JP4644278B2 - Refrigeration cycle equipment - Google Patents

Description

  The present invention relates to a refrigeration cycle apparatus using carbon dioxide as a refrigerant and including a compressor, an outdoor heat exchanger, an expander, and an indoor heat exchanger.

The mass circulation amount of the refrigerant circulating through the refrigeration cycle apparatus is the same at any point in the refrigeration cycle. If the suction density of the refrigerant passing through the compressor is DC and the suction density of the refrigerant passing through the expander is DE, DE / DC ( The density ratio is always kept constant.
On the other hand, ozone depletion is zero and global warming coefficient much smaller compared to CFCs, carbon dioxide (hereinafter, CO of ₂₎ Although the refrigeration cycle apparatus using the refrigerant is focused in recent years, CO ₂ When the refrigerant has a critical temperature as low as 31.06 ° C. and a temperature higher than this temperature is used, the CO ₂ refrigerant is condensed on the high-pressure side of the refrigeration cycle apparatus (compressor outlet to radiator to decompressor inlet). This is a supercritical state in which no refrigeration occurs, and the operating efficiency of the refrigeration cycle apparatus is reduced as compared with conventional refrigerants. Therefore, in the refrigeration cycle apparatus using the CO ₂ refrigerant, it is important to maintain the optimum COP, and when the refrigerant temperature changes, it is necessary to set the optimum refrigerant pressure for the refrigerant temperature.
However, when an expander is provided in the refrigeration cycle apparatus and the power recovered by the expander is used as part of the driving force of the compressor, the rotation speed of the expander and the compressor must be the same. Under the constraint of a constant density ratio, it is difficult to maintain an optimal COP when the operating conditions change.
Therefore, a configuration has been proposed in which an optimum COP is maintained by providing a bypass pipe that bypasses the expander and controlling the amount of refrigerant flowing into the expander (see, for example, Patent Document 1 and Patent Document 2).
JP 2000-234814 A (paragraph numbers (0024) (0025) FIG. 1) JP 2001-116371 A (paragraph number (0023) FIG. 1)

However, as the difference between the volume flow rate flowing into the expander and the optimum design flow rate increases, the amount of refrigerant passing through the bypass increases, and as a result, the power that can be recovered cannot be recovered sufficiently. have.
By using the power recovered by the expander as the driving force of an auxiliary compressor that is different from the compressor, it is possible to remove the restriction that the rotation speed of the expander and the compressor must be the same. is there. However, even when the auxiliary compressor is driven by the expander in this way, the density ratio is limited and it is still necessary to control the amount of refrigerant flowing into the expander.

  Accordingly, an object of the present invention is to avoid the restriction of a constant density ratio as much as possible and to obtain a high power recovery effect in a wide operation range.

The refrigeration cycle apparatus according to the first aspect of the present invention uses carbon dioxide as a refrigerant, and includes a compressor, a first heat exchanger, an expander, and a second heat exchanger, and power recovered by the expander. Is a refrigeration cycle apparatus for driving the compressor, wherein a sub-expander is provided in parallel with the expander, and a generator is connected to the sub-expander.
The refrigeration cycle apparatus of the present invention according to claim 2 uses carbon dioxide as a refrigerant, includes a compressor, a first heat exchanger, an expander, and a second heat exchanger, and recovers power recovered by the expander. Is a refrigeration cycle apparatus used for driving the compressor, wherein a sub-expander connected to a generator is provided on the suction side of the expander.
The refrigeration cycle apparatus of the present invention according to claim 3 uses carbon dioxide as a refrigerant, includes a compressor, a first heat exchanger, an expander, and a second heat exchanger, and recovers power recovered by the expander. Is a refrigeration cycle apparatus used for driving the compressor, wherein a sub-expander connected to a generator is provided on the discharge side of the expander.
The refrigeration cycle apparatus of the present invention described in claim 4 uses carbon dioxide as a refrigerant, includes a compressor, a first heat exchanger, an expander, and a second heat exchanger, and recovers power recovered by the expander. Is used for driving the compressor, wherein a first sub expander is provided on the suction side of the expander, and a second sub expander is provided in parallel with the expander and the first sub expander. A generator is connected to each of the first sub expander and the second sub expander.
The refrigeration cycle apparatus of the present invention according to claim 5 uses carbon dioxide as a refrigerant, and includes a compressor, a first heat exchanger, an expander, and a second heat exchanger, and power recovered by the expander. Is used for driving the compressor, a sub-expander is provided on the suction side of the expander, a bypass flow path is provided in parallel with the expander and the sub-expander, and the bypass flow path is provided. A bypass valve is provided.
The refrigeration cycle apparatus of the present invention described in claim 6 uses carbon dioxide as a refrigerant, and includes a compressor, a first heat exchanger, an expander, and a second heat exchanger, and the power recovered by the expander. In which a pre-expansion valve is provided on the suction side of the expander, and a sub-expander is provided in parallel with the expander and the pre-expansion valve. It is characterized by connecting a generator.
The refrigeration cycle apparatus of the present invention according to claim 7 uses carbon dioxide as a refrigerant, includes a compressor, a first heat exchanger, an expander, and a second heat exchanger, and recovers power recovered by the expander. Is used for driving the compressor, wherein a first sub expander is provided on the suction side of the expander, and a second sub expander is provided in parallel with the expander and the first sub expander. The generator connected to the first sub-expander is a generator connected to the second sub-expander, and the generator is connected to one of the first sub-expander and the second sub-expander. A clutch mechanism is provided.
The refrigeration cycle apparatus of the present invention according to claim 8 uses carbon dioxide as a refrigerant, and includes a compressor, a first heat exchanger, an expander, and a second heat exchanger, and power recovered by the expander. In which the first sub-expander is provided on the discharge side of the expander, and the second sub- expander is provided in parallel with the expander and the first sub-expander. The generator connected to the first sub-expander is a generator connected to the second sub-expander, and the generator is connected to one of the first sub-expander and the second sub-expander. A clutch mechanism is provided.
A ninth aspect of the present invention is the refrigeration cycle apparatus according to any one of the first to eighth aspects, wherein an auxiliary compressor is provided on the suction side of the compressor or the discharge side of the compressor, and the expander The power recovered in step 1 is used as power for driving the auxiliary compressor instead of the compressor.
A tenth aspect of the present invention is the refrigeration cycle apparatus according to any one of the first to eighth aspects, wherein the first four-way valve to which a discharge side pipe and a suction side pipe of the compressor are connected; And a second four-way valve to which the discharge side pipe and the suction side pipe of the expander and the sub-expander are connected, and the first four-way valve allows the refrigerant discharged from the compressor to be discharged into the second heat exchanger. Alternatively, the refrigerant flows through the second heat exchanger as an alternative, and the direction of the refrigerant flowing through the expander and the sub-expander is always the same by the second four-way valve.
The present invention according to claim 11 is the refrigeration cycle apparatus according to claim 9, wherein the first four-way valve to which the discharge side pipe and the suction side pipe of the compressor and the auxiliary compressor are connected, and the expander And a second four-way valve to which a discharge side pipe and a suction side pipe of the sub-expander are connected, and the first four-way valve allows the refrigerant discharged from the compressor and the auxiliary compressor to be discharged to the second Alternatively, the refrigerant flows through the heat exchanger or the second heat exchanger, and the direction of the refrigerant flowing through the expander and the sub-expander is always the same by the second four-way valve.

  According to the present invention, it is possible to avoid the restriction of a constant density ratio as much as possible, and to obtain a high power recovery effect within a wide operation range.

BEST MODE FOR CARRYING OUT THE INVENTION

In the first embodiment of the present invention, a sub-expander is provided in parallel with the expander, and a generator is connected to the sub-expander. By changing the torque of the generator of the sub-expander, The amount of refrigerant flowing through the expander can be changed, and the amount of refrigerant flowing through the expander can be adjusted to an optimum COP. Therefore, power can be efficiently recovered in the expander, and expansion power can also be recovered by converting the expansion power into electric power by the generator using the refrigerant that bypasses the expander.
In the second embodiment of the present invention, the sub-expander connected to the generator is provided on the suction side of the expander, and the pre-expansion refrigerant is changed by changing the torque of the generator of the sub-expander. The amount can be changed and the amount of refrigerant flowing through the expander can be adjusted to an optimum COP. Accordingly, power recovery can be efficiently performed in the expander, and expansion power can also be recovered and converted into electric power by the generator in the sub-expander that performs pre-expansion.
In the third embodiment of the present invention, a sub-expander connected to a generator is provided on the discharge side of the expander, and a refrigerant for additional expansion is obtained by changing the torque of the generator of the sub-expander. The amount can be changed to optimally control the low pressure side pressure. Accordingly, power recovery can be efficiently performed in the expander, and expansion power can be recovered by converting the expansion power into electric power by the generator even in the sub-expander that performs additional expansion.
According to a fourth embodiment of the present invention, a first sub expander is provided on the suction side of the expander, a second sub expander is provided in parallel with the expander and the first sub expander, and the first sub expander and A generator is connected to each of the second sub expanders. By changing the torque of the generator of the first sub expander, the amount of pre-expansion refrigerant is changed, and the amount of refrigerant flowing through the expander is optimized. It can be adjusted to be COP. Further, by changing the torque of the generator of the second sub-expander, the amount of refrigerant flowing through the sub-expander can be changed, and the amount of refrigerant flowing through the expander can be adjusted to an optimum COP. Accordingly, power recovery can be performed efficiently in the expander, and the first sub-expander that performs pre-expansion and the second sub-expander using the refrigerant that bypasses the expander also generate expansion power. It can be converted into electric power and recovered by the machine.
In the fifth embodiment of the present invention, a sub expander is provided on the suction side of the expander, a bypass flow path is provided in parallel with the expander and the sub expander, and a bypass valve is provided in the bypass flow path. By changing the torque of the generator of the sub-expander, the amount of refrigerant for pre-expansion can be changed, and the amount of refrigerant flowing through the expander can be adjusted to an optimum COP. Further, by changing the opening degree of the bypass valve provided in the bypass passage, the amount of refrigerant flowing through the bypass passage can be changed and the amount of refrigerant flowing through the expander can be adjusted to be an optimum COP. Accordingly, power recovery can be efficiently performed in the expander, and expansion power can also be recovered and converted into electric power by the generator in the sub-expander that performs pre-expansion.
In the sixth embodiment of the present invention, a pre-expansion valve is provided on the suction side of the expander, a sub-expander is provided in parallel with the expander and the pre-expansion valve, and a generator is connected to the sub-expander. By changing the opening degree of the pre-expansion valve, the high-pressure side pressure can be changed and the amount of refrigerant flowing through the expander can be adjusted to an optimum COP. In addition, by changing the torque of the generator of the sub-expander, the amount of refrigerant flowing through the sub-expander can be changed and the amount of refrigerant flowing through the expander can be adjusted to an optimum COP. Therefore, power can be efficiently recovered in the expander, and expansion power can also be recovered by converting the expansion power into electric power by the generator using the refrigerant that bypasses the expander.
In the seventh embodiment of the present invention, a first sub-expander is provided on the suction side of the expander, a second sub-expander is provided in parallel with the expander and the first sub-expander, and the first sub-expander is provided. The generator to be connected is a generator that is connected to the second sub-expander, and the generator is provided with a clutch mechanism that is connected to either the first sub-expander or the second sub-expander. According to the present embodiment, by changing the torque of the generator of the first sub-expander, the amount of pre-expansion refrigerant is changed, and the amount of refrigerant flowing through the expander is adjusted to be an optimal COP. Can do. Further, by changing the torque of the generator of the second sub-expander, the amount of refrigerant flowing through the sub-expander can be changed, and the amount of refrigerant flowing through the expander can be adjusted to an optimum COP. Accordingly, power recovery can be efficiently performed in the expander, and the first sub-expander that performs pre-expansion and the second sub-expander using the refrigerant that bypasses the expander also generate expansion power. It can be converted into electric power and recovered by the machine. In addition, the expansion power of the first sub-expander and the second sub-expander can be converted into electric power and recovered by one generator.
In an eighth embodiment of the present invention, a first sub expander is provided on the discharge side of the expander, a second sub expander is provided in parallel with the expander and the first sub expander, and the first sub expander is provided in the first sub expander. The generator to be connected is a generator that is connected to the second sub-expander, and the generator includes a clutch mechanism that connects to either the first sub-expander or the second sub-expander. According to the present embodiment, by changing the torque of the generator of the first sub-expander, the amount of additional expansion refrigerant can be changed, and the low-pressure side pressure can be optimally controlled. Further, by changing the torque of the generator of the second sub-expander, the amount of refrigerant flowing through the sub-expander can be changed, and the amount of refrigerant flowing through the expander can be adjusted to an optimum COP. Accordingly, power recovery can be efficiently performed in the expander, and the first sub-expander that performs pre-expansion and the second sub-expander using the refrigerant that bypasses the expander also generate expansion power. It can be converted into electric power and recovered by the machine. In addition, the expansion power of the first sub-expander and the second sub-expander can be converted into electric power and recovered by one generator.
In the ninth embodiment according to the present invention, the power recovered by the expander in the first to eighth embodiments can be used as power for driving the auxiliary compressor.
According to a tenth embodiment of the present invention, in the first to eighth embodiments, the first four-way valve to which the discharge side pipe and the suction side pipe of the compressor are connected, the expander, and the sub-expander A second four-way valve connected to the discharge-side pipe and the suction-side pipe, and the refrigerant discharged from the compressor is selectively used as the second heat exchanger or the second heat exchanger by the first four-way valve. The first to eighth embodiments can be used as a cooling / heating type air conditioner by always flowing the refrigerant through the expander and the sub-expander by the second four-way valve.
An eleventh embodiment of the present invention is the same as the ninth embodiment except that the first four-way valve, the expander, and the sub-expander are connected to the discharge side pipe and the suction side pipe of the compressor and the auxiliary compressor. And a second four-way valve to which the discharge-side pipe and the suction-side pipe are connected, and the first four-way valve allows the refrigerant discharged from the compressor and the auxiliary compressor to be transferred to the second heat exchanger or the second heat exchanger. The ninth embodiment can be used as an air-conditioning / cooling air conditioner by flowing the refrigerant alternatively through the chamber and always using the second four-way valve so that the direction of refrigerant flowing through the expander and the sub-expander is always the same. .

Hereinafter, a refrigeration cycle apparatus according to an embodiment of the present invention will be described with reference to the drawings for a heat pump type air conditioning apparatus.
FIG. 1 is a configuration diagram of a heat pump air-conditioning type air conditioner according to the present embodiment.
As shown in the figure, the heat pump air-conditioning type air conditioner according to this example uses a CO ₂ refrigerant as a refrigerant, a compressor 1 having a motor 11, an outdoor heat exchanger 3, an expander 6, It is comprised from the refrigerant circuit which connected the indoor side heat exchanger 8 and the auxiliary compressor 10 with piping.
The refrigerant circuit includes a first four-way valve 2 to which the discharge side pipe and the suction side pipe of the compressor 1 are connected, and a second four-way valve to which the discharge side pipe and the suction side pipe of the expander 6 are connected. 4 and a third four-way valve 9 to which the discharge side pipe and the suction side pipe of the auxiliary compressor 10 are connected. In the case of a refrigerant flow in which the outdoor heat exchanger 3 is a radiator and the indoor heat exchanger 8 is an evaporator, the discharge of the auxiliary compressor 10 is performed by switching between the first four-way valve 2 and the third four-way valve 9. The side is configured to be the suction side of the compressor 1. In the case of a refrigerant flow in which the outdoor heat exchanger 3 is an evaporator and the indoor heat exchanger 8 is a radiator, the first four-way valve 2 and the third four-way valve 9 are switched to switch the compressor 1. The discharge side is configured to be the suction side of the auxiliary compressor 10. Moreover, it is comprised so that the refrigerant | coolant direction which flows through the expander 6 may always become the same direction by switching of the 2nd four-way valve 4. FIG.
On the inflow side of the expander 6, a pre-expansion valve 5 capable of changing the valve opening degree is provided. Further, a bypass circuit for bypassing the pre-expansion valve 5 and the expander 6 is provided, and a bypass valve 7 for adjusting the refrigerant flow rate of the bypass circuit is provided in the bypass circuit.
Furthermore, the drive shaft of the expander 6 and the drive shaft of the auxiliary compressor 10 are connected, and the auxiliary compressor 10 is driven by the power recovered by the expander 6.

The operation of the heat pump type air conditioning apparatus according to this embodiment will be described below.
First, the cooling operation mode using the outdoor heat exchanger 3 as a radiator and the indoor heat exchanger 8 as an evaporator will be described. The refrigerant flow in the cooling operation mode is indicated by solid line arrows in the figure.
The refrigerant in the cooling operation mode is compressed and discharged at high temperature and high pressure by the compressor 1 driven by the motor 11, and is introduced into the outdoor heat exchanger 3 through the first four-way valve 2. In the outdoor heat exchanger 3, since the CO ₂ refrigerant is in a supercritical state, it does not enter a gas-liquid two-phase state but radiates heat to an external fluid such as air or water. Thereafter, the CO ₂ refrigerant is introduced into the expander 6 through the second four-way valve 4 and the pre-expansion valve 5 and is decompressed by the expander 6. At this time, for example, the optimum refrigerant amount flowing to the expander 6 is calculated from the high-pressure refrigerant temperature and the high-pressure refrigerant pressure detected at the outlet side of the outdoor heat exchanger 3, and when the volume flow rate is larger than the calculated optimum refrigerant amount, bypass is performed. Controlling the opening degree of the valve 7 in a direction to increase the volume flow rate flowing into the expander 6, and reducing the opening degree of the pre-expansion valve 5 when the volume flow rate is smaller than the calculated optimum refrigerant amount. The degree of opening of the pre-expansion valve 5 or the bypass valve 7 is adjusted so as to increase the volume flow rate by controlling to the above. The decompressed CO ₂ refrigerant passes through the second four-way valve 4 and evaporates in the indoor heat exchanger 8 to absorb heat. Indoor cooling is performed by this heat absorption. The evaporated refrigerant is guided to the auxiliary compressor 10 through the third four-way valve 9, supercharged by the auxiliary compressor 10, and compressed through the third four-way valve 9 and the first four-way valve 2. Inhaled by machine 1. Energy for expansion in the expander 6 is used for supercharging the auxiliary compressor 10 to recover power.

Next, a heating operation mode using the outdoor heat exchanger 3 as an evaporator and the indoor heat exchanger 8 as a radiator will be described. The refrigerant flow in the heating operation mode is indicated by a wavy arrow in the figure.
The refrigerant in the heating operation mode is compressed and discharged at a high temperature and high pressure by the compressor 1 driven by the motor 11, and is guided to the auxiliary compressor 10 through the first four-way valve 2 and the third four-way valve 9. Further overpressure (expressor) is performed by the compressor 10. The overpressure of the auxiliary compressor 10 uses the expansion energy in the expander 6 to recover power. The overpressured refrigerant is introduced into the indoor heat exchanger 8 through the third four-way valve 9. In the indoor heat exchanger 8, since the CO ₂ refrigerant is in a supercritical state, it does not enter a gas-liquid two-phase state but radiates heat to an external fluid such as air or water. Thereafter, the CO ₂ refrigerant is introduced into the expander 6 through the second four-way valve 4 and the pre-expansion valve 5 and is decompressed by the expander 6. At this time, for example, the optimum refrigerant amount flowing to the expander 6 is calculated from the high-pressure refrigerant temperature and the high-pressure refrigerant pressure detected on the outlet side of the indoor heat exchanger 8, and when the volume flow rate is larger than the calculated optimum refrigerant amount, the bypass is calculated. Controlling the opening degree of the valve 7 in a direction to increase the volume flow rate flowing into the expander 6, and reducing the opening degree of the pre-expansion valve 5 when the volume flow rate is smaller than the calculated optimum refrigerant amount. The degree of opening of the pre-expansion valve 5 or the bypass valve 7 is adjusted so as to increase the volume flow rate by controlling to the above. The decompressed CO ₂ refrigerant passes through the second four-way valve 4 and evaporates in the outdoor heat exchanger 3 to absorb heat. The evaporated refrigerant is sucked into the compressor 1 through the first four-way valve 2.

According to the present embodiment, the compressor 1 that compresses the refrigerant, the expander 6 that recovers power, and the auxiliary compressor 10 are installed separately, and supercharging (charger) is performed by the auxiliary compressor 10 in the cooling operation mode. The expander 6 can be operated as a charger-type expander suitable for cooling by using the configuration in which the refrigeration cycle is switched so as to perform overpressure (expressor) in the heating operation mode. It can also be operated as a type of expander.
As described above, according to the present embodiment, it is possible to provide an air conditioner that recovers power using a CO ₂ refrigerant as a refrigerant capable of performing a highly efficient refrigeration cycle operation even in a wide operation range.

Further, in the heat pump type air conditioner according to the present embodiment, the suction volume of the expander 6 is set to 1 cc, the suction volume of the compressor 1 is set to 4 cc, and the suction volume of the auxiliary compressor 10 is set to 4.3 cc. The suction volume of the auxiliary compressor 10 is preferably changed by the amount of the suction density ratio between the compressor 1 and the auxiliary compressor 10. With this configuration, the rotational speeds (frequency in the case of a motor) of the expander 6 and the compressor 1 during cooling can be made substantially the same.
In the configuration of the suction volume, when the heating operation mode is switched, the rotational speed of the auxiliary compressor 10 can be suppressed to a rotational speed lower than the rotational speed of the compressor 1. For example, when the frequency of the compressor 1 is about 60 Hz, the rotational speed of the auxiliary compressor 10 can be about 40 Hz. By reducing this rotational speed, the mechanical loss (sliding resistance and viscous resistance) of the auxiliary compressor 10 can be reduced, and the operating efficiency can be improved.

Next, a heat pump type air conditioner according to another embodiment will be described with reference to FIG.
FIG. 2 is a configuration diagram of the heat pump type air conditioning apparatus according to the present embodiment.
As shown in the figure, the heat pump air-conditioning type air conditioner according to this embodiment has the second four-way valve 4 of the embodiment shown in FIG. 1 as the first check valve bridge circuit 13 and the third four-way valve 8 as the second. The configuration is replaced with a check valve bridge circuit 15, and the other configurations are the same as those in the embodiment shown in FIG.
The first check valve bridge circuit 13 includes a set of four check valves 13a, 13b, 13c, and 13d. Similarly, the second check valve bridge circuit 15 includes a set of four check valves. The check valves 15a, 15b, 15c, and 15d are connected to each other. For example, in the first check valve bridge circuit 13, the refrigerant flows through the check valve 13a and the check valve 13c in the directions indicated by solid arrows during cooling, and flows through the check valve 13b and the check valve 13d in broken lines during heating. It flows in the direction indicated by the arrow and exhibits the same function as the second four-way valve 4.

According to the present embodiment, there is a switching operation, and the check valve structure is completely sealed and simple compared to a semi-sealed and complicated four-way valve structure, which is preferable in terms of seal reliability and control. . In particular, when the pressure is increased to a supercritical region using a CO ₂ refrigerant, the check valve structure according to this embodiment is preferable.
In this embodiment, in the case of a refrigerant flow using the indoor heat exchanger 8 as an evaporator, the discharge side of the auxiliary compressor 10 is the suction side of the compressor 1, and the refrigerant sucked into the compressor 1 by the auxiliary compressor 10 In the case of a refrigerant flow using the indoor heat exchanger 8 as a radiator, the discharge side of the compressor 1 is used as the suction side of the auxiliary compressor 10, and the refrigerant discharged from the compressor 1 is further added. By adopting a refrigeration cycle apparatus that performs pressure (expressor), high efficiency is achieved by reducing the difference in density ratio due to refrigerant flow (operation mode).
The density ratio according to this embodiment will be described with reference to FIG. The refrigerant flow with the indoor heat exchanger 8 as an evaporator is in the cooling operation mode, the refrigerant flow with the indoor heat exchanger 8 as a radiator is in the heating operation mode, and the discharge side of the auxiliary compressor 10 is The case where the compressor 1 is on the suction side is called a charger system, and the case where the discharge side of the compressor 1 is the suction side of the auxiliary compressor 10 is called an expressor system.
For example, a charger type expander optimal for the cooling operation mode is designed with a fixed density ratio of 4.09. When this expander is used, the fixed density ratio at the time of 1/2 rated operation is 3.36. Further, when this expander is used as a charger system, the fixed density ratio at the rated operation in the heating operation mode is 8.50, and the fixed density ratio at the 1/2 rated operation is 8.02.
On the other hand, when this expander is used as an expresser system, the fixed density ratio at the rated operation in the cooling operation mode is 3.00, and the fixed density ratio at the half rated operation is 2.65. The fixed density ratio during rated operation is 5.99, and the fixed density ratio during 1/2 rated operation is 5.29.
If this expander is used as a charger system, the fixed density ratio during rated operation in the cooling operation mode is 4.09, and the fixed density ratio during rated operation in the heating operation mode is 8.50. Therefore, in the comparison at the rated operation, the difference in the fixed density ratio between the cooling operation mode and the heating operation mode is 4.41.
When this expander is used as an expresser system, the fixed density ratio during rated operation in the cooling operation mode is 3.00, and the fixed density ratio during rated operation in the heating operation mode is 5.99. Therefore, in the comparison at the rated operation, the difference in the fixed density ratio between the cooling operation mode and the heating operation mode is 2.99.
On the other hand, as in this embodiment, the expander 6 is set to the charger method during the cooling operation and the expresser method during the heating operation, so that the fixed density ratio in the rated operation in the cooling operation mode is 4.09, Since the fixed density ratio at the rated operation in the heating operation mode is 5.99, in the comparison at the rated operation, the difference in the fixed density ratio between the cooling operation mode and the heating operation mode is 1.90, and the refrigerant flow ( The difference in density ratio due to the operation mode) can be reduced.
The charger / expressor switching method according to this embodiment is the present invention, and the COP value comparison is shown in FIG.
As a comparative example, a method using a bypass valve and a pre-expansion valve in combination and a generator method were used. Here, the method using both the bypass valve and the pre-expansion valve is to provide a bypass valve in a bypass pipe that bypasses the expander, adjust the amount of refrigerant flowing to the bypass pipe by the bypass valve, and Is provided with a pre-expansion valve, and the flow rate of the refrigerant flowing through the expander is adjusted by the pre-expansion valve. In the generator system, power conversion efficiency is considered in comparison with the optimum cycle control state.
FIG. 4 shows the cooling operation mode rating and 1/2 rating, and the heating operation mode rating and COP value at 1/2 rating when the expander is adjusted during the rated operation in the cooling operation mode. Yes.
As shown in FIG. 4, according to the present embodiment, a high COP value can be obtained even when compared with a method using a bypass valve and a pre-expansion valve in combination.
FIG. 5 shows the relationship between the frequency of the compressor 1 and the auxiliary compressor 10 when the cooling operation rated frequency of the auxiliary compressor 10 is set to the same 40 Hz frequency as the cooling operation rated frequency of the compressor 1. As shown in the figure, the heating operation rated frequency of the auxiliary compressor 10 is 39.3 Hz, which is lower than the heating operation rated frequency 60 Hz of the compressor 1, and the half rated frequency during the heating operation of the auxiliary compressor 10 is 18 .4 Hz, which is lower than the 1/2 rated frequency 30 Hz during the heating operation of the compressor 1, and the 1/2 rated frequency during the cooling operation of the auxiliary compressor 10 is 19.6 Hz, during the cooling operation of the compressor 1. The ½ rated frequency is lower than 20 Hz. Moreover, as shown in the figure, the highest efficiency can be obtained by setting the rated frequency of the auxiliary compressor 10 in a range in the vicinity of 40 Hz. That is, in the case of this type of positive displacement compressor, the leakage loss decreases as the rotational speed increases, but the mechanical loss increases as the rotational speed increases, so the rotational speed of 40 Hz becomes a highly efficient rotational speed.

Hereinafter, a refrigeration cycle apparatus according to another embodiment of the present invention will be described with reference to the drawings.
FIG. 6 is a configuration diagram of the heat pump type air conditioner according to the present embodiment.
As shown in the figure, the heat pump type air conditioner according to this example uses a CO ₂ refrigerant as a refrigerant, a compressor 1 having a motor 12, an outdoor heat exchanger 3, an expander 6, and an indoor side. It is comprised from the refrigerant circuit which connected the heat exchanger 8 with piping.
A bypass circuit that bypasses the expander 6 is provided in parallel with the expander 6, and a sub-expander is provided in the bypass circuit, and a generator 22 is connected to a drive shaft of the sub-expander. .
Moreover, the drive shaft of the expander 6 and the drive shaft of the compressor 1 are connected, and the compressor 1 uses the power recovered by the expander 6 for driving.

The operation of the heat pump type air conditioner according to this embodiment will be described below.
The refrigerant is compressed and discharged at a high temperature and high pressure by the compressor 1 driven by the motor 12, and is introduced into the outdoor heat exchanger 3. In the outdoor heat exchanger 3, since the CO ₂ refrigerant is in a supercritical state, it does not enter a gas-liquid two-phase state but radiates heat to an external fluid such as air or water. Thereafter, the CO ₂ refrigerant is introduced into the expander 6 and the sub expander 21 and is decompressed by the expander 6 or the sub expander 21. The power recovered by the expander 6 during the decompression is used to drive the compressor 1. At this time, for example, the optimum refrigerant amount flowing to the expander 6 is calculated from the high-pressure refrigerant temperature and the high-pressure refrigerant pressure detected at the outlet side of the outdoor heat exchanger 3, and power generation is performed when the volume flow rate is larger than the calculated optimum refrigerant amount. The volume flow rate flowing into the expander 6 is decreased by decreasing the torque (generator load) of the machine 22 and increasing the amount of refrigerant flowing through the bypass circuit. Further, when the optimum refrigerant amount flowing through the expander 6 is smaller than the calculated optimum refrigerant amount, the torque (generator load) of the generator 22 is increased to reduce the refrigerant amount flowing into the bypass circuit, thereby flowing into the expander 6. Increase the volume flow rate.
The CO ₂ refrigerant decompressed by the expander 6 and the sub expander 21 evaporates and absorbs heat in the indoor heat exchanger 8. Indoor cooling is performed by this heat absorption. The refrigerant that has been evaporated is sucked into the compressor 1.

  As described above, according to the present embodiment, the expander is configured by adjusting the amount of refrigerant flowing through the bypass circuit by changing the torque of the generator 22 connected to the sub expander 21 (that is, the load of the generator). 6 can be controlled. Accordingly, power can be efficiently recovered in the expander 6, and higher power recovery can be achieved from the refrigeration cycle by using the power recovered from the sub expander 21 for power generation of the generator 22 during this bypass flow rate control. It can be performed.

Hereinafter, a refrigeration cycle apparatus according to another embodiment of the present invention will be described with reference to the drawings for a heat pump type air conditioning apparatus.
FIG. 7 is a configuration diagram of a heat pump type air conditioning apparatus according to the present embodiment.
As shown in the figure, the heat pump air-conditioning type air conditioner according to the present embodiment uses a CO ₂ refrigerant as a refrigerant, a compressor 1 having a motor 12, an outdoor heat exchanger 3, an expander 6, It is comprised from the refrigerant circuit which connected the indoor side heat exchanger 8 with piping.
The refrigerant circuit includes a first four-way valve 2 to which the discharge side pipe and the suction side pipe of the compressor 1 are connected, and a second four-way valve to which the discharge side pipe and the suction side pipe of the expander 6 are connected. 4 is provided.
A bypass circuit that bypasses the expander 6 is provided in parallel with the expander 6, and a sub-expander is provided in the bypass circuit, and a generator 22 is connected to a drive shaft of the sub-expander. . This bypass circuit is also connected to the second four-way valve 4 in the same manner as the expander 6.
Moreover, the drive shaft of the expander 6 and the drive shaft of the compressor 1 are connected, and the compressor 1 uses the power recovered by the expander 6 for driving.

The operation of the heat pump type air conditioning apparatus according to this embodiment will be described below.
First, the cooling operation mode using the outdoor heat exchanger 3 as a radiator and the indoor heat exchanger 8 as an evaporator will be described. The refrigerant flow in the cooling operation mode is indicated by solid line arrows in the figure.
The refrigerant in the cooling operation mode is compressed and discharged at high temperature and high pressure by the compressor 1 driven by the motor 12, and is introduced into the outdoor heat exchanger 3 through the first four-way valve 2. In the outdoor heat exchanger 3, since the CO ₂ refrigerant is in a supercritical state, it does not enter a gas-liquid two-phase state but radiates heat to an external fluid such as air or water. Thereafter, the CO ₂ refrigerant is introduced into the expander 6 and the sub expander 21 through the second four-way valve 4, and decompressed by the expander 6 or the sub expander 21. The power recovered by the expander 6 during the decompression is used to drive the compressor 1. At this time, for example, the optimum refrigerant amount flowing to the expander 6 is calculated from the high-pressure refrigerant temperature and the high-pressure refrigerant pressure detected at the outlet side of the outdoor heat exchanger 3, and power generation is performed when the volume flow rate is larger than the calculated optimum refrigerant amount. The volume flow rate flowing into the expander 6 is decreased by decreasing the torque (generator load) of the machine 22 and increasing the amount of refrigerant flowing through the bypass circuit. Further, when the optimum refrigerant amount flowing through the expander 6 is smaller than the calculated optimum refrigerant amount, the torque (generator load) of the generator 22 is increased to reduce the refrigerant amount flowing into the bypass circuit, thereby flowing into the expander 6. Increase the volume flow rate.
The CO ₂ refrigerant depressurized by the sub-expander 21 and the expander 6 is guided to the indoor heat exchanger 8 via the second four-way valve 4, and evaporates and absorbs heat in the indoor heat exchanger 8. Indoor cooling is performed by this heat absorption. The refrigerant that has been evaporated is sucked into the compressor 1.

Next, a heating operation mode using the outdoor heat exchanger 3 as an evaporator and the indoor heat exchanger 8 as a radiator will be described. The refrigerant flow in the heating operation mode is indicated by a wavy arrow in the figure.
Refrigerant during the heating operation mode is discharged is compressed to high temperature and high pressure by the compressor 1 which is driven by the motor 12, through the first four-way valve 2, is introduced into the indoor heat exchanger 8. In the indoor heat exchanger 8, CO ₂ refrigerant, since a supercritical state, the refrigerant is not brought liquid two-phase state, and radiated to the outside fluid such as air or water, for example room by utilizing the heat radiation Heating is performed. Thereafter, the CO ₂ refrigerant is introduced into the expander 6 and the sub expander 21 through the second four-way valve 4, and decompressed by the expander 6 or the sub expander 21. The power recovered by the expander 6 during the decompression is used to drive the compressor 1. At this time, for example, the optimum refrigerant amount flowing to the expander 6 is calculated from the high-pressure refrigerant temperature and the high-pressure refrigerant pressure detected at the outlet side of the indoor heat exchanger 8, and power generation is performed when the volume flow rate is larger than the calculated optimum refrigerant amount. The volume flow rate flowing into the expander 6 is decreased by decreasing the torque (generator load) of the machine 22 and increasing the amount of refrigerant flowing through the bypass circuit. Further, when the optimum refrigerant amount flowing through the expander 6 is smaller than the calculated optimum refrigerant amount, the torque (generator load) of the generator 22 is increased to reduce the refrigerant amount flowing into the bypass circuit, thereby flowing into the expander 6. Increase the volume flow rate.
CO ₂ refrigerant decompressed by the expander 6 and the sub-expander 21 is introduced into the outdoor heat exchanger 3 through the second four-way valve 4, it absorbs heat and evaporates in the outdoor side heat exchanger 3 The evaporated refrigerant is sucked into the compressor 1 via the first four-way valve 2.

  As described above, according to the present embodiment, the expander is configured by adjusting the amount of refrigerant flowing through the bypass circuit by changing the torque of the generator 22 connected to the sub expander 21 (that is, the load of the generator). 6 can be controlled. Accordingly, power can be efficiently recovered in the expander 6, and higher power recovery can be achieved from the refrigeration cycle by using the power recovered from the sub expander 21 for power generation of the generator 22 during this bypass flow rate control. It can be performed.

Hereinafter, a refrigeration cycle apparatus according to another embodiment of the present invention will be described with reference to the drawings.
FIG. 8 is a configuration diagram of the heat pump type air conditioner according to the present embodiment.
As shown in the figure, the heat pump type air conditioner according to this example uses a CO ₂ refrigerant as a refrigerant, a compressor 1 having a motor 12, an outdoor heat exchanger 3, an expander 6, and an indoor side. It is comprised from the refrigerant circuit which connected the heat exchanger 8 with piping.
A sub expander 23 is provided on the inflow side of the expander 6, and a generator 24 is connected to a drive shaft of the sub expander 23.
Moreover, the drive shaft of the expander 6 and the drive shaft of the compressor 1 are connected, and the compressor 1 uses the power recovered by the expander 6 for driving.

The operation of the heat pump type air conditioner according to this embodiment will be described below.
The refrigerant is compressed and discharged at a high temperature and high pressure by the compressor 1 driven by the motor 12, and is introduced into the outdoor heat exchanger 3. In the outdoor heat exchanger 3, since the CO ₂ refrigerant is in a supercritical state, it does not enter a gas-liquid two-phase state but radiates heat to an external fluid such as air or water. Thereafter, the CO ₂ refrigerant is introduced into the sub expander 23 and the expander 6, and the pressure is reduced by the sub expander 23 and the expander 6. The power recovered by the expander 6 during the decompression is used to drive the compressor 1. At this time, for example, the optimum refrigerant amount flowing to the expander 6 is calculated from the high-pressure refrigerant temperature and the high-pressure refrigerant pressure detected on the outlet side of the outdoor heat exchanger 3, and power generation is performed when the volume flow rate is smaller than the calculated optimum refrigerant amount. The volume flow rate flowing into the expander 6 is increased by increasing the torque (generator load) of the machine 24 and increasing the high-pressure side pressure. Further, when the optimum refrigerant amount flowing into the expander 6 is larger than the calculated optimum refrigerant amount, the volume flow rate flowing into the expander 6 by decreasing the torque (generator load) of the generator 24 and reducing the high-pressure side pressure. Decrease.
The CO ₂ refrigerant decompressed by the sub-expander 23 and the expander 6 is evaporated by the indoor heat exchanger 8 and absorbs heat. Indoor cooling is performed by this heat absorption. The refrigerant that has been evaporated is sucked into the compressor 1.

  As described above, according to this embodiment, the torque of the generator 24 connected to the sub-expander 23 (that is, the load of the generator) is changed to adjust the high-pressure side pressure to flow into the expander 6. The amount of refrigerant can be controlled. Therefore, power can be recovered efficiently in the expander 6, and higher power can be recovered from the refrigeration cycle by using the power recovered from the sub-expander 23 for power generation by the generator 24.

Hereinafter, a refrigeration cycle apparatus according to another embodiment of the present invention will be described with reference to the drawings for a heat pump type air conditioning apparatus.
FIG. 9 is a configuration diagram of a heat pump type air conditioning apparatus according to the present embodiment.
As shown in the figure, the heat pump air-conditioning type air conditioner according to the present embodiment uses a CO ₂ refrigerant as a refrigerant, a compressor 1 having a motor 12, an outdoor heat exchanger 3, an expander 6, It is comprised from the refrigerant circuit which connected the indoor side heat exchanger 8 with piping.
A sub expander 23 is provided on the inflow side of the expander 6, and a generator 24 is connected to a drive shaft of the sub expander 23.
Moreover, the drive shaft of the expander 6 and the drive shaft of the compressor 1 are connected, and the compressor 1 uses the power recovered by the expander 6 for driving.
The refrigerant circuit is connected to the first four-way valve 2 to which the discharge side pipe and the suction side pipe of the compressor 1 are connected, and to the suction side pipe of the sub expander 23 and the discharge side pipe of the expander 6. The second four-way valve 4 is provided.

The operation of the heat pump type air conditioning apparatus according to this embodiment will be described below.
First, the cooling operation mode using the outdoor heat exchanger 3 as a radiator and the indoor heat exchanger 8 as an evaporator will be described. The refrigerant flow in the cooling operation mode is indicated by solid line arrows in the figure.
The refrigerant in the cooling operation mode is compressed and discharged at a high temperature and a high pressure by the compressor 1 driven by the motor 12, and is introduced into the outdoor heat exchanger 3 through the first four-way valve 2. In the outdoor heat exchanger 3, since the CO ₂ refrigerant is in a supercritical state, it does not enter a gas-liquid two-phase state but radiates heat to an external fluid such as air or water. Thereafter, the CO ₂ refrigerant is introduced into the sub expander 23 and the expander 6 through the second four-way valve 4, and is depressurized by the sub expander 23 and the expander 6. The power recovered by the expander 6 during the decompression is used to drive the compressor 1. At this time, for example, the optimum refrigerant amount flowing to the expander 6 is calculated from the high-pressure refrigerant temperature and the high-pressure refrigerant pressure detected on the outlet side of the outdoor heat exchanger 3, and power generation is performed when the volume flow rate is smaller than the calculated optimum refrigerant amount. The volume flow rate flowing into the expander 6 is increased by increasing the torque (generator load) of the machine 24 and increasing the high-pressure side pressure. Further, when the optimum refrigerant amount flowing into the expander 6 is larger than the calculated optimum refrigerant amount, the volume flow rate flowing into the expander 6 by decreasing the torque (generator load) of the generator 24 and reducing the high-pressure side pressure. Decrease.
The CO ₂ refrigerant decompressed by the sub-expander 23 and the expander 6 is guided to the indoor heat exchanger 8 via the second four-way valve 4, and is evaporated and absorbs heat in the indoor heat exchanger 8. Indoor cooling is performed by this heat absorption. The refrigerant that has been evaporated is sucked into the compressor 1.

Next, a heating operation mode using the outdoor heat exchanger 3 as an evaporator and the indoor heat exchanger 8 as a radiator will be described. The refrigerant flow in the heating operation mode is indicated by a wavy arrow in the figure.
Refrigerant during the heating operation mode is discharged is compressed to high temperature and high pressure by the compressor 1 which is driven by the motor 12, through the first four-way valve 2, is introduced into the indoor heat exchanger 8. In the indoor heat exchanger 8, CO ₂ refrigerant, since a supercritical state, the refrigerant is not brought liquid two-phase state, and radiated to the outside fluid such as air or water, for example room by utilizing the heat radiation Heating is performed. Thereafter, the CO ₂ refrigerant is introduced into the sub expander 23 and the expander 6 through the second four-way valve 4, and is depressurized by the sub expander 23 and the expander 6. The power recovered by the expander 6 during the decompression is used to drive the compressor 1. At this time, for example, the optimum refrigerant amount flowing to the expander 6 is calculated from the high-pressure refrigerant temperature and the high-pressure refrigerant pressure detected at the outlet side of the indoor heat exchanger 8, and power generation is performed when the volume flow rate is smaller than the calculated optimum refrigerant amount. The volume flow rate flowing into the expander 6 is increased by increasing the torque (generator load) of the machine 24 and increasing the high-pressure side pressure. Further, when the optimum refrigerant amount flowing into the expander 6 is larger than the calculated optimum refrigerant amount, the volume flow rate flowing into the expander 6 by decreasing the torque (generator load) of the generator 24 and reducing the high-pressure side pressure. Decrease.
The CO ₂ refrigerant depressurized by the sub-expander 23 and the expander 6 evaporates and absorbs heat in the outdoor heat exchanger 3, and the evaporated refrigerant passes through the first four-way valve 2 and is compressed by the compressor 1. Inhaled.

  As described above, according to this embodiment, the torque of the generator 24 connected to the sub-expander 23 (that is, the load of the generator) is changed to adjust the high-pressure side pressure to flow into the expander 6. The amount of refrigerant can be controlled. Therefore, power can be recovered efficiently in the expander 6, and higher power can be recovered from the refrigeration cycle by using the power recovered from the sub-expander 23 for power generation by the generator 24.

Hereinafter, a refrigeration cycle apparatus according to another embodiment of the present invention will be described with reference to the drawings.
FIG. 10 is a configuration diagram of a heat pump type air conditioner according to the present embodiment.
As shown in the figure, the heat pump type air conditioner according to the present embodiment uses a CO ₂ refrigerant as a refrigerant, a compressor 1 having a motor 12, an outdoor heat exchanger 3, an expander 6, and an indoor side. It is comprised from the refrigerant circuit which connected the heat exchanger 8 with piping.
A sub expander 23 is provided on the discharge side of the expander 6, and a generator 24 is connected to the drive shaft of the sub expander 23.
Moreover, the drive shaft of the expander 6 and the drive shaft of the compressor 1 are connected, and the compressor 1 uses the power recovered by the expander 6 for driving.

The operation of the heat pump type air conditioner according to this embodiment will be described below.
The refrigerant is compressed and discharged at a high temperature and high pressure by the compressor 1 driven by the motor 12, and is introduced into the outdoor heat exchanger 3. In the outdoor heat exchanger 3, since the CO ₂ refrigerant is in a supercritical state, it does not enter a gas-liquid two-phase state but radiates heat to an external fluid such as air or water. Thereafter, the CO ₂ refrigerant is introduced into the expander 6 and the sub-expander 23 and decompressed by the expander 6 and the sub-expander 23. The power recovered by the expander 6 during the decompression is used to drive the compressor 1. At this time, for example, the optimum refrigerant amount flowing to the expander 6 is calculated from the high-pressure refrigerant temperature and the high-pressure refrigerant pressure detected on the outlet side of the outdoor heat exchanger 3, and power generation is performed when the volume flow rate is smaller than the calculated optimum refrigerant amount. The volume flow rate flowing into the expander 6 is increased by increasing the torque (generator load) of the machine 22 and lowering the low pressure side pressure. Further, when the optimum refrigerant amount flowing through the expander 6 is larger than the calculated optimum refrigerant amount, the volume flow rate flowing into the expander 6 by decreasing the torque (generator load) of the generator 22 and increasing the low-pressure side pressure. Decrease.
The CO ₂ refrigerant decompressed by the sub-expander 23 and the expander 6 is evaporated by the indoor heat exchanger 8 and absorbs heat. Indoor cooling is performed by this heat absorption. The refrigerant that has been evaporated is sucked into the compressor 1.

  As described above, according to the present embodiment, the low-pressure side pressure is adjusted by changing the torque of the generator 22 connected to the sub-expander 23 (that is, the load of the generator) to flow into the expander 6. The amount of refrigerant can be controlled. Therefore, power can be recovered efficiently in the expander 6, and higher power can be recovered from the refrigeration cycle by using the power recovered from the sub-expander 23 for power generation by the generator 24.

Hereinafter, a refrigeration cycle apparatus according to another embodiment of the present invention will be described with reference to the drawings for a heat pump type air conditioning apparatus.
FIG. 11 is a configuration diagram of a heat pump air-conditioning type air conditioner according to this embodiment.
As shown in the figure, the heat pump air-conditioning type air conditioner according to the present embodiment uses a CO ₂ refrigerant as a refrigerant, a compressor 1 having a motor 12, an outdoor heat exchanger 3, an expander 6, It is comprised from the refrigerant circuit which connected the indoor side heat exchanger 8 with piping.
A sub expander 23 is provided on the discharge side of the expander 6, and a generator 24 is connected to the drive shaft of the sub expander 23.
Moreover, the drive shaft of the expander 6 and the drive shaft of the compressor 1 are connected, and the compressor 1 uses the power recovered by the expander 6 for driving.
And in this refrigerant circuit, the discharge-side pipe of the compressor 1 and the first four-way valve 2 and the suction side pipe is connected to a discharge side pipe of the sub-expander 23 and a suction side pipe of the expander 6 are connected The second four-way valve 4 is provided.

The operation of the heat pump type air conditioning apparatus according to this embodiment will be described below.
First, the cooling operation mode using the outdoor heat exchanger 3 as a radiator and the indoor heat exchanger 8 as an evaporator will be described. The refrigerant flow in the cooling operation mode is indicated by solid line arrows in the figure.
The refrigerant in the cooling operation mode is compressed and discharged at a high temperature and a high pressure by the compressor 1 driven by the motor 12, and is introduced into the outdoor heat exchanger 3 through the first four-way valve 2. In the outdoor heat exchanger 3, since the CO ₂ refrigerant is in a supercritical state, it does not enter a gas-liquid two-phase state but radiates heat to an external fluid such as air or water. Thereafter, the CO ₂ refrigerant is introduced into the expander 6 and the sub expander 23 through the second four-way valve 4, and is decompressed by the expander 6 and the sub expander 23. The power recovered by the expander 6 during the decompression is used to drive the compressor 1. At this time, for example, the optimum refrigerant amount flowing to the expander 6 is calculated from the high-pressure refrigerant temperature and the high-pressure refrigerant pressure detected on the outlet side of the outdoor heat exchanger 3, and power generation is performed when the volume flow rate is smaller than the calculated optimum refrigerant amount. The volume flow rate flowing into the expander 6 is increased by increasing the torque (generator load) of the machine 22 and lowering the low pressure side pressure. Further, when the optimum refrigerant amount flowing through the expander 6 is larger than the calculated optimum refrigerant amount, the volume flow rate flowing into the expander 6 by decreasing the torque (generator load) of the generator 22 and increasing the low-pressure side pressure. Decrease.
The CO ₂ refrigerant decompressed by the expander 6 and the sub-expander 23 is guided to the indoor heat exchanger 8 via the second four-way valve 4 and is evaporated and absorbs heat by the indoor heat exchanger 8. . Indoor cooling is performed by this heat absorption. The refrigerant that has been evaporated is sucked into the compressor 1.

Next, a heating operation mode using the outdoor heat exchanger 3 as an evaporator and the indoor heat exchanger 8 as a radiator will be described. The refrigerant flow in the heating operation mode is indicated by a wavy arrow in the figure.
Refrigerant during the heating operation mode is discharged is compressed to high temperature and high pressure by the compressor 1 which is driven by the motor 12, through the first four-way valve 2, is introduced into the indoor heat exchanger 8. In the indoor heat exchanger 8, CO ₂ refrigerant, since a supercritical state, the refrigerant is not brought liquid two-phase state, and radiated to the outside fluid such as air or water, for example room by utilizing the heat radiation Heating is performed. Thereafter, the CO ₂ refrigerant is introduced into the expander 6 and the sub expander 23 through the second four-way valve 4, and is decompressed by the expander 6 and the sub expander 23. The power recovered by the expander 6 during the decompression is used to drive the compressor 1. At this time, for example, the optimum refrigerant amount flowing to the expander 6 is calculated from the high-pressure refrigerant temperature and the high-pressure refrigerant pressure detected at the outlet side of the indoor heat exchanger 8, and power generation is performed when the volume flow rate is smaller than the calculated optimum refrigerant amount. The volume flow rate flowing into the expander 6 is increased by increasing the torque (generator load) of the machine 22 and lowering the low pressure side pressure. Further, when the optimum refrigerant amount flowing through the expander 6 is larger than the calculated optimum refrigerant amount, the volume flow rate flowing into the expander 6 by decreasing the torque (generator load) of the generator 22 and increasing the low-pressure side pressure. Decrease.
The CO ₂ refrigerant depressurized by the expander 6 and the sub-expander 23 evaporates and absorbs heat in the outdoor heat exchanger 3, and the refrigerant that has finished evaporating passes through the first four-way valve 2 to compress the compressor 1. Inhaled.

  As described above, according to the present embodiment, the low-pressure side pressure is adjusted by changing the torque of the generator 22 connected to the sub-expander 23 (that is, the load of the generator) to flow into the expander 6. The amount of refrigerant can be controlled. Therefore, power can be recovered efficiently in the expander 6, and higher power can be recovered from the refrigeration cycle by using the power recovered from the sub-expander 23 for power generation by the generator 24.

Hereinafter, a refrigeration cycle apparatus according to another embodiment of the present invention will be described with reference to the drawings.
FIG. 12 is a configuration diagram of a heat pump air conditioner according to the present embodiment.
As shown in the figure, the heat pump type air conditioner according to the present embodiment uses a CO ₂ refrigerant as a refrigerant, a compressor 1 having a motor 12, an outdoor heat exchanger 3, an expander 6, and an indoor side. It is comprised from the refrigerant circuit which connected the heat exchanger 8 with piping.
A sub expander 23 is provided on the inflow side of the expander 6, and a generator 24 is connected to a drive shaft of the sub expander 23.
A bypass circuit that bypasses the sub-expander 23 and the expander 6 is provided in parallel with the sub-expander 23 and the expander 6, and the sub-expander 21 is provided in the bypass circuit, and the drive shaft of the sub-expander 21 Is connected to a generator 22.
Moreover, the drive shaft of the expander 6 and the drive shaft of the compressor 1 are connected, and the compressor 1 uses the power recovered by the expander 6 for driving.

The operation of the heat pump type air conditioner according to this embodiment will be described below.
The refrigerant is compressed and discharged at a high temperature and high pressure by the compressor 1 driven by the motor 12, and is introduced into the outdoor heat exchanger 3. In the outdoor heat exchanger 3, since the CO ₂ refrigerant is in a supercritical state, it does not enter a gas-liquid two-phase state but radiates heat to an external fluid such as air or water. Thereafter, the CO ₂ refrigerant is introduced into the sub expander 23, the expander 6, and the sub expander 21, and decompressed by the sub expander 23, the expander 6, and the sub expander 21. The power recovered by the expander 6 during the decompression is used to drive the compressor 1. At this time, for example, the optimum refrigerant amount flowing to the expander 6 is calculated from the high-pressure refrigerant temperature and the high-pressure refrigerant pressure detected at the outlet side of the outdoor heat exchanger 3, and power generation is performed when the volume flow rate is larger than the calculated optimum refrigerant amount. The volume flow rate flowing into the expander 6 is decreased by decreasing the torque (generator load) of the machine 22 and increasing the amount of refrigerant flowing through the bypass circuit. On the other hand, when the volume flow rate is smaller than the calculated optimum refrigerant amount, the volume flow rate flowing into the expander 6 is increased by increasing the torque (generator load) of the generator 24 and increasing the high-pressure side pressure.
CO ₂ refrigerant decompressed by the sub-expander 23 and the expander 6 CO ₂ refrigerant or sub expander 21 that is decompressed by the absorbs heat to evaporate at the indoor heat exchanger 8. Indoor cooling is performed by this heat absorption. The refrigerant that has been evaporated is sucked into the compressor 1.

  As described above, according to the present embodiment, the expander is configured by adjusting the amount of refrigerant flowing through the bypass circuit by changing the torque of the generator 22 connected to the sub expander 21 (that is, the load of the generator). The amount of refrigerant flowing through the sub-expander 23 can be controlled, while the high-pressure side pressure is adjusted by changing the torque of the generator 24 connected to the sub-expander 23 (ie, the load of the generator). It is possible to control the amount of refrigerant flowing in the tank. Therefore, power can be efficiently recovered in the expander 6, and the power recovered from the sub-expander 21 and the sub-expander 23 is used for power generation by the generator 22 and the generator 24. Power recovery can be performed.

Hereinafter, a refrigeration cycle apparatus according to another embodiment of the present invention will be described with reference to the drawings for a heat pump type air conditioning apparatus.
FIG. 13 is a configuration diagram of a heat pump type air conditioning apparatus according to the present embodiment.
As shown in the figure, the heat pump air-conditioning type air conditioner according to the present embodiment uses a CO ₂ refrigerant as a refrigerant, a compressor 1 having a motor 12, an outdoor heat exchanger 3, an expander 6, It is comprised from the refrigerant circuit which connected the indoor side heat exchanger 8 with piping.
A sub expander 23 is provided on the inflow side of the expander 6, and a generator 24 is connected to a drive shaft of the sub expander 23.
A bypass circuit that bypasses the sub-expander 23 and the expander 6 is provided in parallel with the sub-expander 23 and the expander 6, and the sub-expander 21 is provided in the bypass circuit, and the drive shaft of the sub-expander 21 Is connected to a generator 22. This bypass circuit is also connected to the second four-way valve 4 in the same manner as the sub-expander 23 and the expander 6.
Moreover, the drive shaft of the expander 6 and the drive shaft of the compressor 1 are connected, and the compressor 1 uses the power recovered by the expander 6 for driving.
The refrigerant circuit is connected to the first four-way valve 2 to which the discharge side pipe and the suction side pipe of the compressor 1 are connected, and to the suction side pipe of the sub expander 23 and the discharge side pipe of the expander 6. And a second four-way valve 4 to which a bypass circuit is connected.

The operation of the heat pump type air conditioning apparatus according to this embodiment will be described below.
First, the cooling operation mode using the outdoor heat exchanger 3 as a radiator and the indoor heat exchanger 8 as an evaporator will be described. The refrigerant flow in the cooling operation mode is indicated by solid line arrows in the figure.
The refrigerant in the cooling operation mode is compressed and discharged at a high temperature and a high pressure by the compressor 1 driven by the motor 12, and is introduced into the outdoor heat exchanger 3 through the first four-way valve 2. In the outdoor heat exchanger 3, since the CO ₂ refrigerant is in a supercritical state, it does not enter a gas-liquid two-phase state but radiates heat to an external fluid such as air or water. Thereafter, the CO ₂ refrigerant is introduced into the sub expander 23, the expander 6, and the sub expander 21, and decompressed by the sub expander 23, the expander 6, and the sub expander 21. The power recovered by the expander 6 during the decompression is used to drive the compressor 1. At this time, for example, the optimum refrigerant amount flowing to the expander 6 is calculated from the high-pressure refrigerant temperature and the high-pressure refrigerant pressure detected at the outlet side of the outdoor heat exchanger 3, and when the volume flow rate is larger than the calculated optimum refrigerant amount The volume flow rate flowing into the expander 6 is decreased by decreasing the torque (generator load) of the machine 22 and increasing the amount of refrigerant flowing through the bypass circuit. On the other hand, when the volume flow rate is smaller than the calculated optimum refrigerant amount, the volume flow rate flowing into the expander 6 is increased by increasing the torque (generator load) of the generator 24 and increasing the high-pressure side pressure.
CO ₂ refrigerant decompressed by the sub-expander 23 and the expander 6 CO reduced in pressure by _second refrigerant or sub expander 21 is guided to the indoor heat exchanger 8 through the second four-way valve 4, It evaporates and absorbs heat in the indoor heat exchanger 8. Indoor cooling is performed by this heat absorption. The refrigerant that has been evaporated is sucked into the compressor 1.

Next, a heating operation mode using the outdoor heat exchanger 3 as an evaporator and the indoor heat exchanger 8 as a radiator will be described. The refrigerant flow in the heating operation mode is indicated by a wavy arrow in the figure.
Refrigerant during the heating operation mode is discharged is compressed to high temperature and high pressure by the compressor 1 which is driven by the motor 12, through the first four-way valve 2, is introduced into the indoor heat exchanger 8. In the indoor heat exchanger 8, CO ₂ refrigerant, since a supercritical state, the refrigerant is not brought liquid two-phase state, and radiated to the outside fluid such as air or water, for example room by utilizing the heat radiation Heating is performed. Thereafter, the CO ₂ refrigerant is introduced into the sub expander 23, the expander 6, and the sub expander 21, and decompressed by the sub expander 23, the expander 6, and the sub expander 21. The power recovered by the expander 6 during the decompression is used to drive the compressor 1. At this time, for example, the optimum refrigerant amount flowing to the expander 6 is calculated from the high-pressure refrigerant temperature and the high-pressure refrigerant pressure detected at the outlet side of the indoor heat exchanger 8, and power generation is performed when the volume flow rate is larger than the calculated optimum refrigerant amount. The volume flow rate flowing into the expander 6 is decreased by decreasing the torque (generator load) of the machine 22 and increasing the amount of refrigerant flowing through the bypass circuit. On the other hand, when the volume flow rate is smaller than the calculated optimum refrigerant amount, the volume flow rate flowing into the expander 6 is increased by increasing the torque (generator load) of the generator 24 and increasing the high-pressure side pressure.
CO ₂ refrigerant decompressed by the sub-expander 23 and the expander 6 CO reduced in pressure by _second refrigerant or sub expander 21 is guided to the outdoor heat exchanger 3 through the second four-way valve 4, The refrigerant that has evaporated and absorbed heat in the outdoor heat exchanger 3 and has finished evaporation is sucked into the compressor 1 via the first four-way valve 2.

  As described above, according to the present embodiment, the expander is configured by adjusting the amount of refrigerant flowing through the bypass circuit by changing the torque of the generator 22 connected to the sub expander 21 (that is, the load of the generator). The amount of refrigerant flowing through the sub-expander 23 can be controlled, while the high-pressure side pressure is adjusted by changing the torque of the generator 24 connected to the sub-expander 23 (ie, the load of the generator). It is possible to control the amount of refrigerant flowing in the tank. Therefore, power can be efficiently recovered in the expander 6, and the power recovered from the sub-expander 21 and the sub-expander 23 is used for power generation by the generator 22 and the generator 24. Power recovery can be performed.

Hereinafter, a refrigeration cycle apparatus according to another embodiment of the present invention will be described with reference to the drawings.
FIG. 14 is a configuration diagram of a heat pump type air conditioner according to the present embodiment.
As shown in the figure, the heat pump type air conditioner according to this example uses a CO ₂ refrigerant as a refrigerant, a compressor 1 having a motor 12, an outdoor heat exchanger 3, an expander 6, and an indoor side. It is comprised from the refrigerant circuit which connected the heat exchanger 8 with piping.
A sub expander 23 is provided on the inflow side of the expander 6, and a generator 24 is connected to a drive shaft of the sub expander 23.
A bypass circuit that bypasses the sub-expander 23 and the expander 6 is provided in parallel with the sub-expander 23 and the expander 6, and a bypass valve 7 is provided in the bypass circuit.
Moreover, the drive shaft of the expander 6 and the drive shaft of the compressor 1 are connected, and the compressor 1 uses the power recovered by the expander 6 for driving.

The operation of the heat pump type air conditioner according to this embodiment will be described below.
The refrigerant is compressed and discharged at a high temperature and high pressure by the compressor 1 driven by the motor 12, and is introduced into the outdoor heat exchanger 3. In the outdoor heat exchanger 3, since the CO ₂ refrigerant is in a supercritical state, it does not enter a gas-liquid two-phase state but radiates heat to an external fluid such as air or water. Thereafter, the CO ₂ refrigerant is introduced into the sub-expander 23 and the expander 6 and decompressed by the sub-expander 23 and the expander 6. The power recovered by the expander 6 during the decompression is used to drive the compressor 1. At this time, for example, the optimum refrigerant amount flowing to the expander 6 is calculated from the high-pressure refrigerant temperature and the high-pressure refrigerant pressure detected at the outlet side of the outdoor heat exchanger 3, and when the volume flow rate is larger than the calculated optimum refrigerant amount, bypass is performed. By increasing the opening of the valve 7 and increasing the amount of refrigerant flowing through the bypass circuit, the volume flow rate flowing into the expander 6 is decreased. On the other hand, when the volume flow rate is smaller than the calculated optimum refrigerant amount, the volume flow rate flowing into the expander 6 is increased by increasing the torque (generator load) of the generator 24 and increasing the high-pressure side pressure.
The CO ₂ refrigerant decompressed by the sub expander 23 and the expander 6 evaporates and absorbs heat in the indoor heat exchanger 8. Indoor cooling is performed by this heat absorption. The refrigerant that has been evaporated is sucked into the compressor 1.

  As described above, according to this embodiment, the amount of refrigerant flowing through the expander 6 can be controlled by adjusting the amount of refrigerant flowing through the bypass circuit by changing the opening of the bypass valve 7. The amount of refrigerant flowing through the expander 6 can be controlled by changing the torque of the generator 24 connected to the sub-expander 23 (that is, the load of the generator) to adjust the high-pressure side pressure. Therefore, power can be recovered efficiently in the expander 6 and higher power can be recovered from the refrigeration cycle by using the power recovered from the sub-expander 23 for power generation by the generator 22 and the generator 24. Can do.

Hereinafter, a refrigeration cycle apparatus according to another embodiment of the present invention will be described with reference to the drawings for a heat pump type air conditioning apparatus.
FIG. 15 is a configuration diagram of a heat pump air-conditioning type air conditioner according to the present embodiment.
As shown in the figure, the heat pump air-conditioning type air conditioner according to this example uses a CO ₂ refrigerant as a refrigerant, a compressor 1 having a motor 12, an outdoor heat exchanger 3, an expander 6, It is comprised from the refrigerant circuit which connected the indoor side heat exchanger 8 with piping.
A sub expander 23 is provided on the inflow side of the expander 6, and a generator 24 is connected to a drive shaft of the sub expander 23.
A bypass circuit that bypasses the sub-expander 23 and the expander 6 is provided in parallel with the sub-expander 23 and the expander 6, and a bypass valve 7 is provided in the bypass circuit. This bypass circuit is also connected to the second four-way valve 4 in the same manner as the sub-expander 23 and the expander 6.
Moreover, the drive shaft of the expander 6 and the drive shaft of the compressor 1 are connected, and the compressor 1 uses the power recovered by the expander 6 for driving.
The refrigerant circuit is connected to the first four-way valve 2 to which the discharge side pipe and the suction side pipe of the compressor 1 are connected, and to the suction side pipe of the sub expander 23 and the discharge side pipe of the expander 6. And a second four-way valve 4 to which a bypass circuit is connected.

The operation of the heat pump type air conditioning apparatus according to this embodiment will be described below.
First, the cooling operation mode using the outdoor heat exchanger 3 as a radiator and the indoor heat exchanger 8 as an evaporator will be described. The refrigerant flow in the cooling operation mode is indicated by solid line arrows in the figure.
The refrigerant in the cooling operation mode is compressed and discharged at high temperature and high pressure by the compressor 1 driven by the motor 12, and is introduced into the outdoor heat exchanger 3 through the first four-way valve 2. In the outdoor heat exchanger 3, since the CO ₂ refrigerant is in a supercritical state, it does not enter a gas-liquid two-phase state but radiates heat to an external fluid such as air or water. Thereafter, the CO ₂ refrigerant is introduced into the sub-expander 23 and the expander 6 and decompressed by the sub-expander 23 and the expander 6. The power recovered by the expander 6 during the decompression is used to drive the compressor 1. At this time, for example, the optimum refrigerant amount flowing to the expander 6 is calculated from the high-pressure refrigerant temperature and the high-pressure refrigerant pressure detected on the outlet side of the outdoor heat exchanger 3, and when the volume flow rate is larger than the calculated optimum refrigerant amount, bypass is performed. By increasing the opening of the valve 7 and increasing the amount of refrigerant flowing through the bypass circuit, the volume flow rate flowing into the expander 6 is decreased. On the other hand, when the volume flow rate is smaller than the calculated optimum refrigerant amount, the volume flow rate flowing into the expander 6 is increased by increasing the torque (generator load) of the generator 24 and increasing the high-pressure side pressure.
The CO ₂ refrigerant decompressed by the sub-expander 23 and the expander 6 is guided to the indoor heat exchanger 8 via the second four-way valve 4 and is evaporated and absorbs heat in the indoor heat exchanger 8. . Indoor cooling is performed by this heat absorption. The refrigerant that has been evaporated is sucked into the compressor 1.

Next, a heating operation mode using the outdoor heat exchanger 3 as an evaporator and the indoor heat exchanger 8 as a radiator will be described. The refrigerant flow in the heating operation mode is indicated by a wavy arrow in the figure.
The refrigerant in the heating operation mode is compressed and discharged at a high temperature and high pressure by the compressor 1 driven by the motor 12, and is introduced into the indoor heat exchanger 8 through the first four-way valve 2. In the indoor heat exchanger 8, since the CO ₂ refrigerant is in a supercritical state, the CO ₂ refrigerant does not enter a gas-liquid two-phase state but radiates heat to an external fluid such as air or water. Heating is performed. Thereafter, the CO ₂ refrigerant is introduced into the sub-expander 23 and the expander 6 and decompressed by the sub-expander 23 and the expander 6. The power recovered by the expander 6 during the decompression is used to drive the compressor 1. At this time, for example, the optimum refrigerant amount flowing to the expander 6 is calculated from the high-pressure refrigerant temperature and the high-pressure refrigerant pressure detected at the outlet side of the indoor heat exchanger 8, and when the volume flow rate is larger than the calculated optimum refrigerant amount, bypass is performed. By increasing the opening of the valve 7 and increasing the amount of refrigerant flowing through the bypass circuit, the volume flow rate flowing into the expander 6 is decreased. On the other hand, when the volume flow rate is smaller than the calculated optimum refrigerant amount, the volume flow rate flowing into the expander 6 is increased by increasing the torque (generator load) of the generator 24 and increasing the high-pressure side pressure.
The CO ₂ refrigerant decompressed by the sub-expander 23 and the expander 6 is guided to the outdoor heat exchanger 3 via the second four-way valve 4 and is evaporated and absorbs heat in the outdoor heat exchanger 3. The evaporated refrigerant is sucked into the compressor 1 via the first four-way valve 2.

  As described above, according to this embodiment, the amount of refrigerant flowing through the expander 6 can be controlled by adjusting the amount of refrigerant flowing through the bypass circuit by changing the opening of the bypass valve 7. The amount of refrigerant flowing through the expander 6 can be controlled by changing the torque of the generator 24 connected to the sub-expander 23 (that is, the load of the generator) to adjust the high-pressure side pressure. Therefore, power can be recovered efficiently in the expander 6, and higher power can be recovered from the refrigeration cycle by using the power recovered from the sub-expander 23 for power generation by the generator 24.

Hereinafter, a refrigeration cycle apparatus according to another embodiment of the present invention will be described with reference to the drawings.
FIG. 16 is a configuration diagram of a heat pump type air conditioner according to the present embodiment.
As shown in the figure, the heat pump type air conditioner according to the present embodiment uses a CO ₂ refrigerant as a refrigerant, a compressor 1 having a motor 12, an outdoor heat exchanger 3, an expander 6, and an indoor side. It is comprised from the refrigerant circuit which connected the heat exchanger 8 with piping.
A pre-expansion valve 5 is provided on the inflow side of the expander 6.
A bypass circuit for bypassing the pre-expansion valve 5 and the expander 6 is provided in parallel with the pre-expansion valve 5 and the expander 6, and a sub-expander is provided in the bypass circuit. Is connected to a generator 22.
Moreover, the drive shaft of the expander 6 and the drive shaft of the compressor 1 are connected, and the compressor 1 uses the power recovered by the expander 6 for driving.

The operation of the heat pump type air conditioner according to this embodiment will be described below.
The refrigerant is compressed and discharged at a high temperature and high pressure by the compressor 1 driven by the motor 12, and is introduced into the outdoor heat exchanger 3. In the outdoor heat exchanger 3, since the CO ₂ refrigerant is in a supercritical state, it does not enter a gas-liquid two-phase state but radiates heat to an external fluid such as air or water. Thereafter, the CO ₂ refrigerant is introduced into the pre-expansion valve 5, the expander 6, and the sub-expander 21, and decompressed by the pre-expansion valve 5, the expander 6, and the sub-expander 21. The power recovered by the expander 6 during the decompression is used to drive the compressor 1. At this time, for example, the optimum refrigerant amount flowing to the expander 6 is calculated from the high-pressure refrigerant temperature and the high-pressure refrigerant pressure detected at the outlet side of the outdoor heat exchanger 3, and when the volume flow rate is larger than the calculated optimum refrigerant amount The volume flow rate flowing into the expander 6 is decreased by decreasing the torque (generator load) of the machine 22 and increasing the amount of refrigerant flowing through the bypass circuit. On the other hand, when the volume flow rate is smaller than the calculated optimum refrigerant amount, the volume flow rate flowing into the expander 6 is increased by decreasing the opening of the pre-expansion valve 5 and increasing the high-pressure side pressure.
CO ₂ refrigerant decompressed by the pre-expansion valve 5 and the expander 6 CO ₂ refrigerant or sub expander 21 that is decompressed by the absorbs heat to evaporate at the indoor heat exchanger 8. Indoor cooling is performed by this heat absorption. The refrigerant that has been evaporated is sucked into the compressor 1.

  As described above, according to the present embodiment, the expander is configured by adjusting the amount of refrigerant flowing through the bypass circuit by changing the torque of the generator 22 connected to the sub expander 21 (that is, the load of the generator). The amount of refrigerant flowing to the expander 6 can be controlled by changing the opening of the pre-expansion valve 5 and adjusting the high-pressure side pressure. Therefore, power can be efficiently recovered in the expander 6, and higher power recovery can be performed from the refrigeration cycle by using the power recovered from the sub expander 21 for power generation by the generator 22 and the generator 24. Can do.

Hereinafter, a refrigeration cycle apparatus according to another embodiment of the present invention will be described with reference to the drawings for a heat pump type air conditioning apparatus.
FIG. 17 is a configuration diagram of a heat pump air-conditioning type air conditioner according to the present embodiment.
As shown in the figure, the heat pump air-conditioning type air conditioner according to this example uses a CO ₂ refrigerant as a refrigerant, a compressor 1 having a motor 12, an outdoor heat exchanger 3, an expander 6, It is comprised from the refrigerant circuit which connected the indoor side heat exchanger 8 with piping.
A pre-expansion valve 5 is provided on the inflow side of the expander 6.
A bypass circuit for bypassing the pre-expansion valve 5 and the expander 6 is provided in parallel with the pre-expansion valve 5 and the expander 6, and a sub-expander is provided in the bypass circuit. Is connected to a generator 22. This bypass circuit is also connected to the second four-way valve 4 in the same manner as the sub-expander 23 and the expander 6.
Moreover, the drive shaft of the expander 6 and the drive shaft of the compressor 1 are connected, and the compressor 1 uses the power recovered by the expander 6 for driving.
The refrigerant circuit is connected to the first four-way valve 2 to which the discharge side pipe and the suction side pipe of the compressor 1 are connected, and to the suction side pipe of the pre-expansion valve 5 and the discharge side pipe of the expander 6. And a second four-way valve 4 to which a bypass circuit is connected.

The operation of the heat pump type air conditioning apparatus according to this embodiment will be described below.
First, the cooling operation mode using the outdoor heat exchanger 3 as a radiator and the indoor heat exchanger 8 as an evaporator will be described. The refrigerant flow in the cooling operation mode is indicated by solid line arrows in the figure.
The refrigerant in the cooling operation mode is compressed and discharged at a high temperature and a high pressure by the compressor 1 driven by the motor 12, and is introduced into the outdoor heat exchanger 3 through the first four-way valve 2. In the outdoor heat exchanger 3, since the CO ₂ refrigerant is in a supercritical state, it does not enter a gas-liquid two-phase state but radiates heat to an external fluid such as air or water. Thereafter, the CO ₂ refrigerant is introduced into the pre-expansion valve 5, the expander 6, and the sub-expander 21, and decompressed by the pre-expansion valve 5, the expander 6, and the sub-expander 21. The power recovered by the expander 6 during the decompression is used to drive the compressor 1. At this time, for example, the optimum refrigerant amount flowing to the expander 6 is calculated from the high-pressure refrigerant temperature and the high-pressure refrigerant pressure detected at the outlet side of the outdoor heat exchanger 3, and when the volume flow rate is larger than the calculated optimum refrigerant amount The volume flow rate flowing into the expander 6 is decreased by decreasing the torque (generator load) of the machine 22 and increasing the amount of refrigerant flowing through the bypass circuit. On the other hand, when the volume flow rate is smaller than the calculated optimum refrigerant amount, the volume flow rate flowing into the expander 6 is increased by decreasing the opening of the pre-expansion valve 5 and increasing the high-pressure side pressure.
CO ₂ refrigerant decompressed by the pre-expansion valve 5 and the expander 6 CO ₂ refrigerant or sub expander 21 that is decompressed by is guided to the indoor heat exchanger 8 through the second four-way valve 4, It evaporates and absorbs heat in the indoor heat exchanger 8. Indoor cooling is performed by this heat absorption. The refrigerant that has been evaporated is sucked into the compressor 1.

Next, a heating operation mode using the outdoor heat exchanger 3 as an evaporator and the indoor heat exchanger 8 as a radiator will be described. The refrigerant flow in the heating operation mode is indicated by a wavy arrow in the figure.
The refrigerant in the heating operation mode is compressed and discharged at a high temperature and high pressure by the compressor 1 driven by the motor 12, and is introduced into the indoor heat exchanger 8 through the first four-way valve 2. In the indoor heat exchanger 8, since the CO ₂ refrigerant is in a supercritical state, the CO ₂ refrigerant does not enter a gas-liquid two-phase state but radiates heat to an external fluid such as air or water. Heating is performed. Thereafter, the CO ₂ refrigerant is introduced into the pre-expansion valve 5, the expander 6, and the sub-expander 21, and decompressed by the pre-expansion valve 5, the expander 6, and the sub-expander 21. The power recovered by the expander 6 during the decompression is used to drive the compressor 1. At this time, for example, the optimum refrigerant amount flowing to the expander 6 is calculated from the high-pressure refrigerant temperature and the high-pressure refrigerant pressure detected on the outlet side of the indoor heat exchanger 8, and power generation is performed when the volume flow rate is larger than the calculated optimum refrigerant amount. The volume flow rate flowing into the expander 6 is decreased by decreasing the torque (generator load) of the machine 22 and increasing the amount of refrigerant flowing through the bypass circuit. On the other hand, when the volume flow rate is smaller than the calculated optimum refrigerant amount, the volume flow rate flowing into the expander 6 is increased by decreasing the opening of the pre-expansion valve 5 and increasing the high-pressure side pressure.
CO ₂ refrigerant decompressed by the pre-expansion valve 5 and the expander 6 CO reduced in pressure by _second refrigerant or sub expander 21 is guided to the outdoor heat exchanger 3 through the second four-way valve 4, The refrigerant that has evaporated and absorbed heat in the outdoor heat exchanger 3 and has finished evaporation is sucked into the compressor 1 via the first four-way valve 2.

  As described above, according to the present embodiment, the expander is configured by adjusting the amount of refrigerant flowing through the bypass circuit by changing the torque of the generator 22 connected to the sub expander 21 (that is, the load of the generator). The amount of refrigerant flowing to the expander 6 can be controlled by changing the opening of the pre-expansion valve 5 and adjusting the high-pressure side pressure. Therefore, power can be recovered efficiently in the expander 6 and higher power can be recovered from the refrigeration cycle by using the power recovered from the sub-expander 21 for power generation by the generator 22.

Hereinafter, a refrigeration cycle apparatus according to another embodiment of the present invention will be described with reference to the drawings.
FIG. 18 is a configuration diagram of the heat pump type air conditioner according to the present embodiment.
As shown in the figure, the heat pump type air conditioner according to the present embodiment uses a CO ₂ refrigerant as a refrigerant, a compressor 1 having a motor 12, an outdoor heat exchanger 3, an expander 6, and an indoor side. It is comprised from the refrigerant circuit which connected the heat exchanger 8 with piping.
A sub expander 23 is provided on the inflow side of the expander 6, and a generator 22 is connected to a drive shaft of the sub expander 23.
A bypass circuit that bypasses the sub-expander 23 and the expander 6 is provided in parallel with the sub-expander 23 and the expander 6, and the sub-expander 21 is provided in the bypass circuit, and the drive shaft of the sub-expander 21 Is connected to a generator 22.
Here, the generator 22 includes a clutch mechanism connected to either the sub-expander 21 or the sub-expander 23. A flow path valve 25 is provided on the inflow side of the bypass circuit.
Moreover, the drive shaft of the expander 6 and the drive shaft of the compressor 1 are connected, and the compressor 1 uses the power recovered by the expander 6 for driving.

The operation of the heat pump type air conditioner according to this embodiment will be described below.
The refrigerant is compressed and discharged at a high temperature and high pressure by the compressor 1 driven by the motor 12, and is introduced into the outdoor heat exchanger 3. In the outdoor heat exchanger 3, since the CO ₂ refrigerant is in a supercritical state, it does not enter a gas-liquid two-phase state but radiates heat to an external fluid such as air or water. Thereafter, the CO ₂ refrigerant is introduced into the sub-expander 23 and the expander 6 and decompressed by the sub-expander 23 and the expander 6. The power recovered by the expander 6 during the decompression is used to drive the compressor 1. At this time, for example, the optimum refrigerant amount flowing to the expander 6 is calculated from the high-pressure refrigerant temperature and the high-pressure refrigerant pressure detected on the outlet side of the outdoor heat exchanger 3, and when the volume flow rate is larger than the calculated optimum refrigerant amount, The flow rate valve 25 is opened, the generator 22 is connected to the sub-expander 21 side, and the refrigerant flows through the bypass circuit to reduce the volume flow rate flowing into the expander 6. In this case, the sub expander 23 is not operated. Further, it is preferable to change the bypass amount by adjusting the torque of the generator 22. On the other hand, when the volume flow rate is smaller than the calculated optimum refrigerant amount, the flow volume 25 is closed and the generator 22 is connected to the sub-expander 23 side to increase the high-pressure side pressure and flow into the expander 6. Increase the flow rate. In this case, the sub expander 21 is not operated. It is preferable to change the high-pressure side pressure by adjusting the torque of the generator 22.
Sub expander 23 and CO ₂ refrigerant decompressed by the expander 6, or CO ₂ refrigerant decompressed by the sub-expander 21 and the expander 6, absorbs heat and evaporates in the indoor heat exchanger 8. Indoor cooling is performed by this heat absorption. The refrigerant that has been evaporated is sucked into the compressor 1.

  As described above, according to the present embodiment, the amount of refrigerant flowing through the expander 6 is adjusted by adjusting the amount of refrigerant flowing through the bypass circuit by opening the on-off valve 25 and connecting the generator 22 to the sub-expander 21. On the other hand, by adjusting the high-pressure side pressure by changing the torque of the generator 24 connected to the sub-expander 23 (ie, the load of the generator) by closing the on-off valve 25, the expander 6 can be controlled. Accordingly, power can be efficiently recovered in the expander 6, and the power recovered from the sub-expander 21 or the sub-expander 23 is used for power generation by the generator 22 and the generator 24. Power recovery can be performed.

Hereinafter, a refrigeration cycle apparatus according to another embodiment of the present invention will be described with reference to the drawings for a heat pump type air conditioning apparatus.
FIG. 19 is a configuration diagram of a heat pump type air conditioning apparatus according to the present embodiment.
As shown in the figure, the heat pump air-conditioning type air conditioner according to this example uses a CO ₂ refrigerant as a refrigerant, a compressor 1 having a motor 12, an outdoor heat exchanger 3, an expander 6, It is comprised from the refrigerant circuit which connected the indoor side heat exchanger 8 with piping.
A sub expander 23 is provided on the inflow side of the expander 6, and a generator 22 is connected to a drive shaft of the sub expander 23.
A bypass circuit that bypasses the sub-expander 23 and the expander 6 is provided in parallel with the sub-expander 23 and the expander 6, and the sub-expander 21 is provided in the bypass circuit, and the drive shaft of the sub-expander 21 Is connected to a generator 22. This bypass circuit is also connected to the second four-way valve 4 in the same manner as the sub-expander 23 and the expander 6.
Here, the generator 22 includes a clutch mechanism connected to either the sub-expander 21 or the sub-expander 23. A flow path valve 25 is provided on the inflow side of the bypass circuit.
Moreover, the drive shaft of the expander 6 and the drive shaft of the compressor 1 are connected, and the compressor 1 uses the power recovered by the expander 6 for driving.
The refrigerant circuit is connected to the first four-way valve 2 to which the discharge side pipe and the suction side pipe of the compressor 1 are connected, and to the suction side pipe of the sub expander 23 and the discharge side pipe of the expander 6. And a second four-way valve 4 to which a bypass circuit is connected.

The operation of the heat pump type air conditioning apparatus according to this embodiment will be described below.
First, the cooling operation mode using the outdoor heat exchanger 3 as a radiator and the indoor heat exchanger 8 as an evaporator will be described. The refrigerant flow in the cooling operation mode is indicated by solid line arrows in the figure.
The refrigerant in the cooling operation mode is compressed and discharged at a high temperature and a high pressure by the compressor 1 driven by the motor 12, and is introduced into the outdoor heat exchanger 3 through the first four-way valve 2. In the outdoor heat exchanger 3, since the CO ₂ refrigerant is in a supercritical state, it does not enter a gas-liquid two-phase state but radiates heat to an external fluid such as air or water. Thereafter, the CO ₂ refrigerant is introduced into the sub-expander 23 and the expander 6 and decompressed by the sub-expander 23 and the expander 6. The power recovered by the expander 6 during the decompression is used to drive the compressor 1. At this time, for example, the optimum refrigerant amount flowing to the expander 6 is calculated from the high-pressure refrigerant temperature and the high-pressure refrigerant pressure detected on the outlet side of the outdoor heat exchanger 3, and when the volume flow rate is larger than the calculated optimum refrigerant amount, The flow rate valve 25 is opened, the generator 22 is connected to the sub-expander 21 side, and the refrigerant flows through the bypass circuit to reduce the volume flow rate flowing into the expander 6. In this case, the sub expander 23 is not operated. Further, it is preferable to change the bypass amount by adjusting the torque of the generator 22. On the other hand, when the volume flow rate is smaller than the calculated optimum refrigerant amount, the flow path valve 25 is closed, the generator 22 is connected to the sub expander 23 side, and the high pressure side pressure is increased to flow into the expander 6. Increase volume flow. In this case, the sub expander 21 is not operated. It is preferable to change the high-pressure side pressure by adjusting the torque of the generator 22.
CO ₂ refrigerant decompressed by the sub-expander 23 and the expander 6, or the sub-expander 21 and CO ₂ refrigerant decompressed by the expander 6, an indoor heat exchanger through the second four-way valve 4 8 evaporates in the indoor heat exchanger 8 and absorbs heat. Indoor cooling is performed by this heat absorption. The refrigerant that has been evaporated is sucked into the compressor 1.

Next, a heating operation mode using the outdoor heat exchanger 3 as an evaporator and the indoor heat exchanger 8 as a radiator will be described. The refrigerant flow in the heating operation mode is indicated by a wavy arrow in the figure.
The refrigerant in the heating operation mode is compressed and discharged at a high temperature and high pressure by the compressor 1 driven by the motor 12, and is introduced into the indoor heat exchanger 8 through the first four-way valve 2. In the indoor heat exchanger 8, since the CO ₂ refrigerant is in a supercritical state, the CO ₂ refrigerant does not enter a gas-liquid two-phase state but radiates heat to an external fluid such as air or water. Heating is performed. Thereafter, the CO ₂ refrigerant is introduced into the sub-expander 23 and the expander 6 and decompressed by the sub-expander 23 and the expander 6. The power recovered by the expander 6 during the decompression is used to drive the compressor 1. At this time, for example, the optimum refrigerant amount flowing to the expander 6 is calculated from the high-pressure refrigerant temperature and the high-pressure refrigerant pressure detected at the outlet side of the indoor heat exchanger 8, and when the volume flow rate is larger than the calculated optimum refrigerant amount, The flow rate valve 25 is opened, the generator 22 is connected to the sub-expander 21 side, and the refrigerant flows through the bypass circuit to reduce the volume flow rate flowing into the expander 6. In this case, the sub expander 23 is not operated. Further, it is preferable to change the bypass amount by adjusting the torque of the generator 22. On the other hand, when the volume flow rate is smaller than the calculated optimum refrigerant amount, the flow path valve 25 is closed, the generator 22 is connected to the sub expander 23 side, and the high pressure side pressure is increased to flow into the expander 6. Increase volume flow. In this case, the sub expander 21 is not operated. It is preferable to change the high-pressure side pressure by adjusting the torque of the generator 22.
CO ₂ refrigerant decompressed by the sub-expander 23 and the expander 6, or the sub-expander 21 and CO ₂ refrigerant decompressed by the expander 6, an outdoor heat exchanger via the second four-way valve 4 3, the refrigerant evaporating and absorbing heat in the outdoor heat exchanger 3, and the evaporated refrigerant is sucked into the compressor 1 through the first four-way valve 2.

  As described above, according to the present embodiment, the amount of refrigerant flowing through the expander 6 is adjusted by adjusting the amount of refrigerant flowing through the bypass circuit by opening the on-off valve 25 and connecting the generator 22 to the sub-expander 21. On the other hand, by adjusting the high-pressure side pressure by changing the torque of the generator 24 connected to the sub-expander 23 (ie, the load of the generator) by closing the on-off valve 25, the expander 6 can be controlled. Accordingly, power can be efficiently recovered in the expander 6, and the power recovered from the sub-expander 21 or the sub-expander 23 is used for power generation by the generator 22 and the generator 24. Power recovery can be performed.

Hereinafter, a refrigeration cycle apparatus according to another embodiment of the present invention will be described with reference to the drawings.
FIG. 20 is a configuration diagram of a heat pump type air conditioner according to the present embodiment.
As shown in the figure, the heat pump type air conditioner according to the present embodiment uses a CO ₂ refrigerant as a refrigerant, a compressor 1 having a motor 12, an outdoor heat exchanger 3, an expander 6, and an indoor side. It is comprised from the refrigerant circuit which connected the heat exchanger 8 with piping.
A sub-expander 23 is provided on the discharge side of the expander 6, and a generator 22 is connected to the drive shaft of the sub-expander 23.
A bypass circuit that bypasses the sub-expander 23 and the expander 6 is provided in parallel with the sub-expander 23 and the expander 6, and the sub-expander 21 is provided in the bypass circuit, and the drive shaft of the sub-expander 21 Is connected to a generator 22.
Here, the generator 22 includes a clutch mechanism connected to either the sub-expander 21 or the sub-expander 23. A flow path valve 25 is provided on the inflow side of the bypass circuit.
Moreover, the drive shaft of the expander 6 and the drive shaft of the compressor 1 are connected, and the compressor 1 uses the power recovered by the expander 6 for driving.

The operation of the heat pump type air conditioner according to this embodiment will be described below.
The refrigerant is compressed and discharged at a high temperature and high pressure by the compressor 1 driven by the motor 12, and is introduced into the outdoor heat exchanger 3. In the outdoor heat exchanger 3, since the CO ₂ refrigerant is in a supercritical state, it does not enter a gas-liquid two-phase state but radiates heat to an external fluid such as air or water. Thereafter, the CO ₂ refrigerant is introduced into the expander 6 and the sub-expander 23 and decompressed by the expander 6 and the sub-expander 23. The power recovered by the expander 6 during the decompression is used to drive the compressor 1. At this time, for example, the optimum refrigerant amount flowing to the expander 6 is calculated from the high-pressure refrigerant temperature and the high-pressure refrigerant pressure detected on the outlet side of the outdoor heat exchanger 3, and when the volume flow rate is larger than the calculated optimum refrigerant amount, The flow rate valve 25 is opened, the generator 22 is connected to the sub-expander 21 side, and the refrigerant flows through the bypass circuit to reduce the volume flow rate flowing into the expander 6. In this case, the sub expander 23 is not operated. Further, it is preferable to change the bypass amount by adjusting the torque of the generator 22. On the other hand, when the volume flow rate is smaller than the calculated optimum refrigerant amount, the flow path valve 25 is closed, and the generator 22 is connected to the sub-expander 23 side to reduce the low-pressure side pressure, thereby flowing into the expander 6. Increase the volume flow rate. In this case, the sub expander 21 is not operated. Moreover, it is preferable to change the low pressure side pressure by adjusting the torque of the generator 22.
Sub expander 23 and CO ₂ refrigerant decompressed by the expander 6, or CO ₂ refrigerant decompressed by the sub-expander 21 and the expander 6, absorbs heat and evaporates in the indoor heat exchanger 8. Indoor cooling is performed by this heat absorption. The refrigerant that has been evaporated is sucked into the compressor 1.

  As described above, according to the present embodiment, the amount of refrigerant flowing through the expander 6 is adjusted by adjusting the amount of refrigerant flowing through the bypass circuit by opening the on-off valve 25 and connecting the generator 22 to the sub-expander 21. On the other hand, by adjusting the low pressure side pressure by changing the torque of the generator 24 connected to the sub-expander 23 (ie, the load of the generator) by closing the on-off valve 25, the expander 6 can be controlled. Accordingly, power can be efficiently recovered in the expander 6, and the power recovered from the sub-expander 21 or the sub-expander 23 is used for power generation by the generator 22 and the generator 24. Power recovery can be performed.

Hereinafter, a refrigeration cycle apparatus according to another embodiment of the present invention will be described with reference to the drawings for a heat pump type air conditioning apparatus.
FIG. 21 is a configuration diagram of a heat pump type air conditioning apparatus according to the present embodiment.
As shown in the figure, the heat pump air-conditioning type air conditioner according to this example uses a CO ₂ refrigerant as a refrigerant, a compressor 1 having a motor 12, an outdoor heat exchanger 3, an expander 6, It is comprised from the refrigerant circuit which connected the indoor side heat exchanger 8 with piping.
A sub-expander 23 is provided on the discharge side of the expander 6, and a generator 22 is connected to the drive shaft of the sub-expander 23.
A bypass circuit that bypasses the sub-expander 23 and the expander 6 is provided in parallel with the sub-expander 23 and the expander 6, and the sub-expander 21 is provided in the bypass circuit, and the drive shaft of the sub-expander 21 Is connected to a generator 22. This bypass circuit is also connected to the second four-way valve 4 in the same manner as the sub-expander 23 and the expander 6.
Here, the generator 22 includes a clutch mechanism connected to either the sub-expander 21 or the sub-expander 23. A flow path valve 25 is provided on the inflow side of the bypass circuit.
Moreover, the drive shaft of the expander 6 and the drive shaft of the compressor 1 are connected, and the compressor 1 uses the power recovered by the expander 6 for driving.
The refrigerant circuit is connected to the first four-way valve 2 to which the discharge side pipe and the suction side pipe of the compressor 1 are connected, the discharge side pipe of the sub expander 23 and the inflow side pipe of the expander 6. And a second four-way valve 4 to which a bypass circuit is connected.

The operation of the heat pump type air conditioning apparatus according to this embodiment will be described below.
First, the cooling operation mode using the outdoor heat exchanger 3 as a radiator and the indoor heat exchanger 8 as an evaporator will be described. The refrigerant flow in the cooling operation mode is indicated by solid line arrows in the figure.
The refrigerant in the cooling operation mode is compressed and discharged at a high temperature and a high pressure by the compressor 1 driven by the motor 12, and is introduced into the outdoor heat exchanger 3 through the first four-way valve 2. In the outdoor heat exchanger 3, since the CO ₂ refrigerant is in a supercritical state, it does not enter a gas-liquid two-phase state but radiates heat to an external fluid such as air or water. Thereafter, the CO ₂ refrigerant is introduced into the expander 6 and the sub-expander 23 and decompressed by the expander 6 and the sub-expander 23. The power recovered by the expander 6 during the decompression is used to drive the compressor 1. At this time, for example, the optimum refrigerant amount flowing to the expander 6 is calculated from the high-pressure refrigerant temperature and the high-pressure refrigerant pressure detected on the outlet side of the outdoor heat exchanger 3, and when the volume flow rate is larger than the calculated optimum refrigerant amount, The flow rate valve 25 is opened, the generator 22 is connected to the sub-expander 21 side, and the refrigerant flows through the bypass circuit to reduce the volume flow rate flowing into the expander 6. In this case, the sub expander 23 is not operated. Further, it is preferable to change the bypass amount by adjusting the torque of the generator 22. On the other hand, when the volume flow rate is smaller than the calculated optimum refrigerant amount, the flow path valve 25 is closed, the generator 22 is connected to the sub expander 23 side, and the low pressure side pressure is lowered to flow into the expander 6. Increase volume flow. In this case, the sub expander 21 is not operated. Moreover, it is preferable to change the low pressure side pressure by adjusting the torque of the generator 22.
CO ₂ refrigerant decompressed by the sub-expander 23 and the expander 6, or the sub-expander 21 and CO ₂ refrigerant decompressed by the expander 6, an indoor heat exchanger through the second four-way valve 4 8 evaporates in the indoor heat exchanger 8 and absorbs heat. Indoor cooling is performed by this heat absorption. The refrigerant that has been evaporated is sucked into the compressor 1.

Next, a heating operation mode using the outdoor heat exchanger 3 as an evaporator and the indoor heat exchanger 8 as a radiator will be described. The refrigerant flow in the heating operation mode is indicated by a wavy arrow in the figure.
The refrigerant in the heating operation mode is compressed and discharged at a high temperature and high pressure by the compressor 1 driven by the motor 12, and is introduced into the indoor heat exchanger 8 through the first four-way valve 2. In the indoor heat exchanger 8, since the CO ₂ refrigerant is in a supercritical state, the CO ₂ refrigerant does not enter a gas-liquid two-phase state but radiates heat to an external fluid such as air or water. Heating is performed. Thereafter, the CO ₂ refrigerant is introduced into the expander 6 and the sub-expander 23 and decompressed by the expander 6 and the sub-expander 23. The power recovered by the expander 6 during the decompression is used to drive the compressor 1. At this time, for example, the optimum refrigerant amount flowing to the expander 6 is calculated from the high-pressure refrigerant temperature and the high-pressure refrigerant pressure detected at the outlet side of the indoor heat exchanger 8, and when the volume flow rate is larger than the calculated optimum refrigerant amount, The flow rate valve 25 is opened, the generator 22 is connected to the sub-expander 21 side, and the refrigerant flows through the bypass circuit to reduce the volume flow rate flowing into the expander 6. In this case, the sub expander 23 is not operated. Further, it is preferable to change the bypass amount by adjusting the torque of the generator 22. On the other hand, when the volume flow rate is smaller than the calculated optimum refrigerant amount, the flow path valve 25 is closed, the generator 22 is connected to the sub expander 23 side, and the low pressure side pressure is lowered to flow into the expander 6. Increase volume flow. In this case, the sub expander 21 is not operated. Moreover, it is preferable to change the low pressure side pressure by adjusting the torque of the generator 22.
CO ₂ refrigerant decompressed by the sub-expander 23 and the expander 6, or the sub-expander 21 and CO ₂ refrigerant decompressed by the expander 6, an outdoor heat exchanger via the second four-way valve 4 3, the refrigerant evaporating and absorbing heat in the outdoor heat exchanger 3, and the evaporated refrigerant is sucked into the compressor 1 through the first four-way valve 2.

  As described above, according to the present embodiment, the amount of refrigerant flowing through the expander 6 is adjusted by adjusting the amount of refrigerant flowing through the bypass circuit by opening the on-off valve 25 and connecting the generator 22 to the sub-expander 21. On the other hand, by adjusting the low-pressure side pressure by changing the torque of the generator 22 connected to the sub-expander 23 (ie, the load of the generator) by closing the on-off valve 25, the expander 6 can be controlled. Therefore, power can be efficiently recovered in the expander 6, and higher power recovery is performed from the refrigeration cycle by using the power recovered from the sub expander 21 or the sub expander 23 for power generation of the generator 22. be able to.

Hereinafter, a refrigeration cycle apparatus according to another embodiment of the present invention will be described with reference to the drawings for a heat pump type air conditioning apparatus.
FIG. 22 is a configuration diagram of a heat pump air-conditioning type air conditioner according to the present embodiment.
As shown in the figure, the heat pump air-conditioning type air conditioner according to the present embodiment uses a CO ₂ refrigerant as a refrigerant, a compressor 1 having a motor 12, an outdoor heat exchanger 3, an expander 6, It is comprised from the refrigerant circuit which connected the indoor side heat exchanger 8 and the auxiliary compressor 10 with piping.
The refrigerant circuit is connected to the first four-way valve 2 to which the discharge side piping of the compressor 1 and the suction side piping of the auxiliary compressor 10 are connected, and to the discharge side piping and suction side piping of the expander 6. And a second four-way valve 4.
A bypass circuit that bypasses the expander 6 is provided in parallel with the expander 6, a sub-expander 21 is provided in the bypass circuit, and a generator 22 is connected to the drive shaft of the sub-expander 21. . This bypass circuit is also connected to the second four-way valve 4 in the same manner as the expander 6.
Further, the drive shaft of the expander 6 and the drive shaft of the auxiliary compressor 10 are connected, and the auxiliary compressor 10 is driven by the power recovered by the expander 6.

The operation of the heat pump type air conditioning apparatus according to this embodiment will be described below.
First, the cooling operation mode using the outdoor heat exchanger 3 as a radiator and the indoor heat exchanger 8 as an evaporator will be described. The refrigerant flow in the cooling operation mode is indicated by solid line arrows in the figure.
The refrigerant in the cooling operation mode is compressed and discharged at a high temperature and a high pressure by the compressor 1 driven by the motor 12, and is introduced into the outdoor heat exchanger 3 through the first four-way valve 2. In the outdoor heat exchanger 3, since the CO ₂ refrigerant is in a supercritical state, it does not enter a gas-liquid two-phase state but radiates heat to an external fluid such as air or water. Thereafter, the CO ₂ refrigerant is introduced into the expander 6 and the sub expander 21 through the second four-way valve 4, and decompressed by the expander 6 or the sub expander 21. The power recovered by the expander 6 during this decompression is used to drive the auxiliary compressor 10. At this time, for example, the optimum refrigerant amount flowing to the expander 6 is calculated from the high-pressure refrigerant temperature and the high-pressure refrigerant pressure detected at the outlet side of the outdoor heat exchanger 3, and when the volume flow rate is larger than the calculated optimum refrigerant amount The volume flow rate flowing into the expander 6 is decreased by decreasing the torque (generator load) of the machine 22 and increasing the amount of refrigerant flowing through the bypass circuit. Further, when the optimum refrigerant amount flowing through the expander 6 is smaller than the calculated optimum refrigerant amount, the torque (generator load) of the generator 22 is increased to reduce the refrigerant amount flowing into the bypass circuit, thereby flowing into the expander 6. Increase the volume flow rate.
The CO ₂ refrigerant decompressed by the sub-expander 21 and the expander 6 is guided to the indoor heat exchanger 8 via the second four-way valve 4 and is evaporated and absorbs heat in the indoor heat exchanger 8. Indoor cooling is performed by this heat absorption. The evaporated refrigerant is led to the auxiliary compressor 10 through the first four-way valve 2, supercharged (charged) by the auxiliary compressor 10, and sucked into the compressor 1.

Next, a heating operation mode using the outdoor heat exchanger 3 as an evaporator and the indoor heat exchanger 8 as a radiator will be described. The refrigerant flow in the heating operation mode is indicated by a wavy arrow in the figure.
The refrigerant in the heating operation mode is compressed and discharged at a high temperature and high pressure by the compressor 1 driven by the motor 12, and is introduced into the indoor heat exchanger 8 through the first four-way valve 2. In the indoor heat exchanger 8, since the CO ₂ refrigerant is in a supercritical state, the CO ₂ refrigerant does not enter a gas-liquid two-phase state but radiates heat to an external fluid such as air or water. Heating is performed. Thereafter, the CO ₂ refrigerant is introduced into the expander 6 and the sub expander 21 through the second four-way valve 4, and decompressed by the expander 6 or the sub expander 21. The power recovered by the expander 6 during this decompression is used to drive the auxiliary compressor 10. At this time, for example, the optimum refrigerant amount flowing to the expander 6 is calculated from the high-pressure refrigerant temperature and the high-pressure refrigerant pressure detected on the outlet side of the indoor heat exchanger 8, and power generation is performed when the volume flow rate is larger than the calculated optimum refrigerant amount. The volume flow rate flowing into the expander 6 is decreased by decreasing the torque (generator load) of the machine 22 and increasing the amount of refrigerant flowing through the bypass circuit. Further, when the optimum refrigerant amount flowing through the expander 6 is smaller than the calculated optimum refrigerant amount, the torque (generator load) of the generator 22 is increased to reduce the refrigerant amount flowing into the bypass circuit, thereby flowing into the expander 6. Increase the volume flow rate.
The CO ₂ refrigerant decompressed by the expander 6 and the sub-expander 21 is guided to the outdoor heat exchanger 3 via the second four-way valve 4 and is evaporated and absorbs heat by the outdoor heat exchanger 3. The evaporated refrigerant is led to the auxiliary compressor 10 via the first four-way valve 2, supercharged (charged) by the auxiliary compressor 10, and sucked into the compressor 1.

  As described above, according to the present embodiment, the expander is configured by adjusting the amount of refrigerant flowing through the bypass circuit by changing the torque of the generator 22 connected to the sub expander 21 (that is, the load of the generator). 6 can be controlled. Accordingly, power can be efficiently recovered in the expander 6, and higher power recovery can be achieved from the refrigeration cycle by using the power recovered from the sub expander 21 for power generation of the generator 22 during this bypass flow rate control. It can be performed.

Hereinafter, a refrigeration cycle apparatus according to another embodiment of the present invention will be described with reference to the drawings for a heat pump type air conditioning apparatus.
FIG. 23 is a configuration diagram of a heat pump air-conditioning type air conditioner according to the present embodiment.
As shown in the figure, the heat pump type air conditioning apparatus according to the present embodiment uses a CO ₂ refrigerant as a refrigerant, a compressor 1 having a motor 12, an auxiliary compressor 10, an outdoor heat exchanger 3, and The expander 6 and the indoor heat exchanger 8 are configured by a refrigerant circuit connected by piping.
The refrigerant circuit is connected to the first four-way valve 2 to which the suction side piping of the compressor 1 and the discharge side piping of the auxiliary compressor 10 are connected, and to the discharge side piping and suction side piping of the expander 6. The second four-way valve 4 is provided.
A bypass circuit that bypasses the expander 6 is provided in parallel with the expander 6, a sub-expander 21 is provided in the bypass circuit, and a generator 22 is connected to the drive shaft of the sub-expander 21. . This bypass circuit is also connected to the second four-way valve 4 in the same manner as the expander 6.
Further, the drive shaft of the expander 6 and the drive shaft of the auxiliary compressor 10 are connected, and the auxiliary compressor 10 is driven by the power recovered by the expander 6.

The operation of the heat pump type air conditioning apparatus according to this embodiment will be described below.
First, the cooling operation mode using the outdoor heat exchanger 3 as a radiator and the indoor heat exchanger 8 as an evaporator will be described. The refrigerant flow in the cooling operation mode is indicated by solid line arrows in the figure.
The refrigerant in the cooling operation mode is compressed and discharged at a high temperature and a high pressure by the compressor 1 driven by the motor 12, guided to the auxiliary compressor 10, and further overpressure (expressor) by the auxiliary compressor 10. Then, it is introduced into the outdoor heat exchanger 3 through the first four-way valve 2. In the outdoor heat exchanger 3, since the CO ₂ refrigerant is in a supercritical state, it does not enter a gas-liquid two-phase state but radiates heat to an external fluid such as air or water. Thereafter, the CO ₂ refrigerant is introduced into the expander 6 and the sub expander 21 through the second four-way valve 4, and decompressed by the expander 6 or the sub expander 21. The power recovered by the expander 6 during this decompression is used to drive the auxiliary compressor 10. At this time, for example, the optimum refrigerant amount flowing to the expander 6 is calculated from the high-pressure refrigerant temperature and the high-pressure refrigerant pressure detected at the outlet side of the outdoor heat exchanger 3, and when the volume flow rate is larger than the calculated optimum refrigerant amount The volume flow rate flowing into the expander 6 is decreased by decreasing the torque (generator load) of the machine 22 and increasing the amount of refrigerant flowing through the bypass circuit. Further, when the optimum refrigerant amount flowing through the expander 6 is smaller than the calculated optimum refrigerant amount, the torque (generator load) of the generator 22 is increased to reduce the refrigerant amount flowing into the bypass circuit, thereby flowing into the expander 6. Increase the volume flow rate.
The CO ₂ refrigerant decompressed by the sub-expander 21 and the expander 6 is guided to the indoor heat exchanger 8 via the second four-way valve 4 and is evaporated and absorbs heat in the indoor heat exchanger 8. Indoor cooling is performed by this heat absorption. The evaporated refrigerant is sucked into the compressor 1 through the first four-way valve 2.

Next, a heating operation mode using the outdoor heat exchanger 3 as an evaporator and the indoor heat exchanger 8 as a radiator will be described. The refrigerant flow in the heating operation mode is indicated by a wavy arrow in the figure.
The refrigerant in the heating operation mode is compressed and discharged at a high temperature and high pressure by the compressor 1 driven by the motor 12, guided to the auxiliary compressor 10, and further overpressure (expressor) by the auxiliary compressor 10. Then, it is introduced into the indoor heat exchanger 8 through the first four-way valve 2. In the indoor heat exchanger 8, since the CO ₂ refrigerant is in a supercritical state, the CO ₂ refrigerant does not enter a gas-liquid two-phase state but radiates heat to an external fluid such as air or water. Heating is performed. Thereafter, the CO ₂ refrigerant is introduced into the expander 6 and the sub expander 21 through the second four-way valve 4, and decompressed by the expander 6 or the sub expander 21. The power recovered by the expander 6 during this decompression is used to drive the auxiliary compressor 10. At this time, for example, the optimum refrigerant amount flowing to the expander 6 is calculated from the high-pressure refrigerant temperature and the high-pressure refrigerant pressure detected on the outlet side of the indoor heat exchanger 8, and power generation is performed when the volume flow rate is larger than the calculated optimum refrigerant amount. The volume flow rate flowing into the expander 6 is decreased by decreasing the torque (generator load) of the machine 22 and increasing the amount of refrigerant flowing through the bypass circuit. Further, when the optimum refrigerant amount flowing through the expander 6 is smaller than the calculated optimum refrigerant amount, the torque (generator load) of the generator 22 is increased to reduce the refrigerant amount flowing into the bypass circuit, thereby flowing into the expander 6. Increase the volume flow rate.
The CO ₂ refrigerant depressurized by the expander 6 and the sub-expander 21 is guided to the outdoor heat exchanger 3 via the second four-way valve 4 and is evaporated and absorbs heat in the outdoor heat exchanger 3. The evaporated refrigerant is sucked into the compressor 1 via the first four-way valve 2.

  As described above, according to the present embodiment, the expander is configured by adjusting the amount of refrigerant flowing through the bypass circuit by changing the torque of the generator 22 connected to the sub expander 21 (that is, the load of the generator). 6 can be controlled. Accordingly, power can be efficiently recovered in the expander 6, and higher power recovery can be achieved from the refrigeration cycle by using the power recovered from the sub expander 21 for power generation of the generator 22 during this bypass flow rate control. It can be performed.

Hereinafter, a refrigeration cycle apparatus according to another embodiment of the present invention will be described with reference to the drawings for a heat pump type air conditioning apparatus.
FIG. 24 is a configuration diagram of a heat pump type air conditioning apparatus according to the present embodiment.
As shown in the figure, the heat pump air-conditioning type air conditioner according to the present embodiment uses a CO ₂ refrigerant as a refrigerant, a compressor 1 having a motor 12, an outdoor heat exchanger 3, an expander 6, It is comprised from the refrigerant circuit which connected the indoor side heat exchanger 8 and the auxiliary compressor 10 with piping.
A sub expander 23 is provided on the inflow side of the expander 6, and a generator 24 is connected to a drive shaft of the sub expander 23.
Further, the drive shaft of the expander 6 and the drive shaft of the auxiliary compressor 10 are connected, and the auxiliary compressor 10 is driven by the power recovered by the expander 6.
The refrigerant circuit includes a first four-way valve 2 to which a discharge side pipe of the compressor 1 and a suction side pipe of the auxiliary compressor 10 are connected, a suction side pipe of the sub expander 23, and a discharge side of the expander 6. And a second four-way valve 4 connected to the pipe.

The operation of the heat pump type air conditioning apparatus according to this embodiment will be described below.
First, the cooling operation mode using the outdoor heat exchanger 3 as a radiator and the indoor heat exchanger 8 as an evaporator will be described. The refrigerant flow in the cooling operation mode is indicated by solid line arrows in the figure.
The refrigerant in the cooling operation mode is compressed and discharged at a high temperature and a high pressure by the compressor 1 driven by the motor 12, and is introduced into the outdoor heat exchanger 3 through the first four-way valve 2. In the outdoor heat exchanger 3, since the CO ₂ refrigerant is in a supercritical state, it does not enter a gas-liquid two-phase state but radiates heat to an external fluid such as air or water. Thereafter, the CO ₂ refrigerant is introduced into the sub expander 23 and the expander 6 through the second four-way valve 4, and is depressurized by the sub expander 23 and the expander 6. The power recovered by the expander 6 during this decompression is used to drive the auxiliary compressor 10. At this time, for example, the optimum refrigerant amount flowing to the expander 6 is calculated from the high-pressure refrigerant temperature and the high-pressure refrigerant pressure detected on the outlet side of the outdoor heat exchanger 3, and power generation is performed when the volume flow rate is smaller than the calculated optimum refrigerant amount. The volume flow rate flowing into the expander 6 is increased by increasing the torque (generator load) of the machine 24 and increasing the high-pressure side pressure. Further, when the optimum refrigerant amount flowing into the expander 6 is larger than the calculated optimum refrigerant amount, the volume flow rate flowing into the expander 6 by decreasing the torque (generator load) of the generator 24 and reducing the high-pressure side pressure. Decrease.
The CO ₂ refrigerant decompressed by the sub-expander 23 and the expander 6 is guided to the indoor heat exchanger 8 via the second four-way valve 4, and is evaporated and absorbs heat in the indoor heat exchanger 8. Indoor cooling is performed by this heat absorption. The evaporated refrigerant is led to the auxiliary compressor 10 through the first four-way valve 2, supercharged (charged) by the auxiliary compressor 10, and sucked into the compressor 1.

Next, a heating operation mode using the outdoor heat exchanger 3 as an evaporator and the indoor heat exchanger 8 as a radiator will be described. The refrigerant flow in the heating operation mode is indicated by a wavy arrow in the figure.
The refrigerant in the heating operation mode is compressed and discharged at a high temperature and high pressure by the compressor 1 driven by the motor 12, and is introduced into the indoor heat exchanger 8 through the first four-way valve 2. In the indoor heat exchanger 8, since the CO ₂ refrigerant is in a supercritical state, the CO ₂ refrigerant does not enter a gas-liquid two-phase state but radiates heat to an external fluid such as air or water. Heating is performed. Thereafter, the CO ₂ refrigerant is introduced into the sub expander 23 and the expander 6 through the second four-way valve 4, and is depressurized by the sub expander 23 and the expander 6. The power recovered by the expander 6 during this decompression is used to drive the auxiliary compressor 10. At this time, for example, the optimum refrigerant amount flowing to the expander 6 is calculated from the high-pressure refrigerant temperature and the high-pressure refrigerant pressure detected at the outlet side of the indoor heat exchanger 8, and power generation is performed when the volume flow rate is smaller than the calculated optimum refrigerant amount. The volume flow rate flowing into the expander 6 is increased by increasing the torque (generator load) of the machine 24 and increasing the high-pressure side pressure. Further, when the optimum refrigerant amount flowing into the expander 6 is larger than the calculated optimum refrigerant amount, the volume flow rate flowing into the expander 6 by decreasing the torque (generator load) of the generator 24 and reducing the high-pressure side pressure. Decrease.
The CO ₂ refrigerant depressurized by the sub-expander 23 and the expander 6 evaporates and absorbs heat in the outdoor heat exchanger 3, and the refrigerant that has finished evaporating passes through the first four-way valve 2 and serves as an auxiliary compressor. 10 is supercharged (charged) by the auxiliary compressor 10 and sucked into the compressor 1.

  As described above, according to this embodiment, the torque of the generator 24 connected to the sub-expander 23 (that is, the load of the generator) is changed to adjust the high-pressure side pressure to flow into the expander 6. The amount of refrigerant can be controlled. Therefore, power can be recovered efficiently in the expander 6, and higher power can be recovered from the refrigeration cycle by using the power recovered from the sub-expander 23 for power generation by the generator 24.

Hereinafter, a refrigeration cycle apparatus according to another embodiment of the present invention will be described with reference to the drawings for a heat pump type air conditioning apparatus.
FIG. 25 is a configuration diagram of a heat pump type air conditioning apparatus according to the present embodiment.
As shown in the figure, the heat pump type air conditioning apparatus according to the present embodiment uses a CO ₂ refrigerant as a refrigerant, a compressor 1 having a motor 12, an auxiliary compressor 10, an outdoor heat exchanger 3, and The expander 6 and the indoor heat exchanger 8 are configured by a refrigerant circuit connected by piping.
A sub expander 23 is provided on the inflow side of the expander 6, and a generator 24 is connected to a drive shaft of the sub expander 23.
Further, the drive shaft of the expander 6 and the drive shaft of the auxiliary compressor 10 are connected, and the auxiliary compressor 10 is driven by the power recovered by the expander 6.
The refrigerant circuit includes a first four-way valve 2 to which a suction side pipe of the compressor 1 and a discharge side pipe of the auxiliary compressor 10 are connected, a suction side pipe of the sub expander 23, and a discharge side of the expander 6. And a second four-way valve 4 connected to the pipe.

The operation of the heat pump type air conditioning apparatus according to this embodiment will be described below.
First, the cooling operation mode using the outdoor heat exchanger 3 as a radiator and the indoor heat exchanger 8 as an evaporator will be described. The refrigerant flow in the cooling operation mode is indicated by solid line arrows in the figure.
The refrigerant in the cooling operation mode is compressed and discharged at a high temperature and a high pressure by the compressor 1 driven by the motor 12, guided to the auxiliary compressor 10, and further overpressure (expressor) by the auxiliary compressor 10. Then, it is introduced into the outdoor heat exchanger 3 through the first four-way valve 2. In the outdoor heat exchanger 3, since the CO ₂ refrigerant is in a supercritical state, it does not enter a gas-liquid two-phase state but radiates heat to an external fluid such as air or water. Thereafter, the CO ₂ refrigerant is introduced into the sub expander 23 and the expander 6 through the second four-way valve 4, and is depressurized by the sub expander 23 and the expander 6. The power recovered by the expander 6 during this decompression is used to drive the auxiliary compressor 10. At this time, for example, the optimum refrigerant amount flowing to the expander 6 is calculated from the high-pressure refrigerant temperature and the high-pressure refrigerant pressure detected on the outlet side of the outdoor heat exchanger 3, and power generation is performed when the volume flow rate is smaller than the calculated optimum refrigerant amount. The volume flow rate flowing into the expander 6 is increased by increasing the torque (generator load) of the machine 24 and increasing the high-pressure side pressure. Further, when the optimum refrigerant amount flowing into the expander 6 is larger than the calculated optimum refrigerant amount, the volume flow rate flowing into the expander 6 by decreasing the torque (generator load) of the generator 24 and reducing the high-pressure side pressure. Decrease.
The CO ₂ refrigerant decompressed by the sub-expander 23 and the expander 6 is guided to the indoor heat exchanger 8 via the second four-way valve 4, and is evaporated and absorbs heat in the indoor heat exchanger 8. Indoor cooling is performed by this heat absorption. The evaporated refrigerant is sucked into the compressor 1 through the first four-way valve 2.

Next, a heating operation mode using the outdoor heat exchanger 3 as an evaporator and the indoor heat exchanger 8 as a radiator will be described. The refrigerant flow in the heating operation mode is indicated by a wavy arrow in the figure.
The refrigerant in the heating operation mode is compressed and discharged at a high temperature and high pressure by the compressor 1 driven by the motor 12, guided to the auxiliary compressor 10, and further overpressure (expressor) by the auxiliary compressor 10. Then, it is introduced into the indoor heat exchanger 8 through the first four-way valve 2. In the indoor heat exchanger 8, since the CO ₂ refrigerant is in a supercritical state, the CO ₂ refrigerant does not enter a gas-liquid two-phase state but radiates heat to an external fluid such as air or water. Heating is performed. Thereafter, the CO ₂ refrigerant is introduced into the sub expander 23 and the expander 6 through the second four-way valve 4, and is depressurized by the sub expander 23 and the expander 6. The power recovered by the expander 6 during this decompression is used to drive the auxiliary compressor 10. At this time, for example, the optimum refrigerant amount flowing to the expander 6 is calculated from the high-pressure refrigerant temperature and the high-pressure refrigerant pressure detected at the outlet side of the indoor heat exchanger 8, and power generation is performed when the volume flow rate is smaller than the calculated optimum refrigerant amount. The volume flow rate flowing into the expander 6 is increased by increasing the torque (generator load) of the machine 24 and increasing the high-pressure side pressure. Further, when the optimum refrigerant amount flowing into the expander 6 is larger than the calculated optimum refrigerant amount, the volume flow rate flowing into the expander 6 by decreasing the torque (generator load) of the generator 24 and reducing the high-pressure side pressure. Decrease.
The CO ₂ refrigerant depressurized by the sub-expander 23 and the expander 6 evaporates and absorbs heat in the outdoor heat exchanger 3, and the evaporated refrigerant passes through the first four-way valve 2 and is compressed by the compressor 1. Inhaled.

  As described above, according to this embodiment, the torque of the generator 24 connected to the sub-expander 23 (that is, the load of the generator) is changed to adjust the high-pressure side pressure to flow into the expander 6. The amount of refrigerant can be controlled. Therefore, power can be recovered efficiently in the expander 6, and higher power can be recovered from the refrigeration cycle by using the power recovered from the sub-expander 23 for power generation by the generator 24.

Hereinafter, a refrigeration cycle apparatus according to another embodiment of the present invention will be described with reference to the drawings for a heat pump type air conditioning apparatus.
FIG. 26 is a configuration diagram of a heat pump air-conditioning type air conditioner according to the present embodiment.
As shown in the figure, the heat pump air-conditioning type air conditioner according to the present embodiment uses a CO ₂ refrigerant as a refrigerant, a compressor 1 having a motor 12, an outdoor heat exchanger 3, an expander 6, It is comprised from the refrigerant circuit which connected the indoor side heat exchanger 8 and the auxiliary compressor 10 with piping.
A sub expander 23 is provided on the discharge side of the expander 6, and a generator 24 is connected to the drive shaft of the sub expander 23.
Further, the drive shaft of the expander 6 and the drive shaft of the auxiliary compressor 10 are connected, and the auxiliary compressor 10 is driven by the power recovered by the expander 6.
In this refrigerant circuit, the first four-way valve 2 to which the discharge side piping of the compressor 1 and the suction side piping of the auxiliary compressor 10 are connected, the discharge side piping of the sub expander 23 and the suction side of the expander 6 are connected. And a second four-way valve 4 connected to the pipe.

The operation of the heat pump type air conditioning apparatus according to this embodiment will be described below.
First, the cooling operation mode using the outdoor heat exchanger 3 as a radiator and the indoor heat exchanger 8 as an evaporator will be described. The refrigerant flow in the cooling operation mode is indicated by solid line arrows in the figure.
The refrigerant in the cooling operation mode is compressed and discharged at a high temperature and a high pressure by the compressor 1 driven by the motor 12, and is introduced into the outdoor heat exchanger 3 through the first four-way valve 2. In the outdoor heat exchanger 3, since the CO ₂ refrigerant is in a supercritical state, it does not enter a gas-liquid two-phase state but radiates heat to an external fluid such as air or water. Thereafter, the CO ₂ refrigerant is introduced into the expander 6 and the sub expander 23 through the second four-way valve 4, and is decompressed by the expander 6 and the sub expander 23. The power recovered by the expander 6 during this decompression is used to drive the auxiliary compressor 10. At this time, for example, the optimum refrigerant amount flowing to the expander 6 is calculated from the high-pressure refrigerant temperature and the high-pressure refrigerant pressure detected on the outlet side of the outdoor heat exchanger 3, and power generation is performed when the volume flow rate is smaller than the calculated optimum refrigerant amount. The volume flow rate flowing into the expander 6 is increased by increasing the torque (generator load) of the machine 22 and lowering the low pressure side pressure. Further, when the optimum refrigerant amount flowing through the expander 6 is larger than the calculated optimum refrigerant amount, the volume flow rate flowing into the expander 6 by decreasing the torque (generator load) of the generator 22 and increasing the low-pressure side pressure. Decrease.
The CO ₂ refrigerant decompressed by the expander 6 and the sub-expander 23 is guided to the indoor heat exchanger 8 via the second four-way valve 4 and is evaporated and absorbs heat by the indoor heat exchanger 8. . Indoor cooling is performed by this heat absorption. The evaporated refrigerant is led to the auxiliary compressor 10 through the first four-way valve 2, supercharged (charged) by the auxiliary compressor 10, and sucked into the compressor 1.

Next, a heating operation mode using the outdoor heat exchanger 3 as an evaporator and the indoor heat exchanger 8 as a radiator will be described. The refrigerant flow in the heating operation mode is indicated by a wavy arrow in the figure.
The refrigerant in the heating operation mode is compressed and discharged at a high temperature and high pressure by the compressor 1 driven by the motor 12, and is introduced into the indoor heat exchanger 8 through the first four-way valve 2. In the indoor heat exchanger 8, since the CO ₂ refrigerant is in a supercritical state, the CO ₂ refrigerant does not enter a gas-liquid two-phase state but radiates heat to an external fluid such as air or water. Heating is performed. Thereafter, the CO ₂ refrigerant is introduced into the expander 6 and the sub expander 23 through the second four-way valve 4, and is decompressed by the expander 6 and the sub expander 23. The power recovered by the expander 6 during this decompression is used to drive the auxiliary compressor 10. At this time, for example, the optimum refrigerant amount flowing to the expander 6 is calculated from the high-pressure refrigerant temperature and the high-pressure refrigerant pressure detected at the outlet side of the indoor heat exchanger 8, and power generation is performed when the volume flow rate is smaller than the calculated optimum refrigerant amount. The volume flow rate flowing into the expander 6 is increased by increasing the torque (generator load) of the machine 22 and lowering the low pressure side pressure. Further, when the optimum refrigerant amount flowing through the expander 6 is larger than the calculated optimum refrigerant amount, the volume flow rate flowing into the expander 6 by decreasing the torque (generator load) of the generator 22 and increasing the low-pressure side pressure. Decrease.
The CO ₂ refrigerant decompressed by the expander 6 and the sub-expander 23 evaporates and absorbs heat in the outdoor heat exchanger 3, and the refrigerant that has finished evaporating passes through the first four-way valve 2 and serves as an auxiliary compressor. 10 is supercharged (charged) by the auxiliary compressor 10 and sucked into the compressor 1.

  As described above, according to the present embodiment, the low-pressure side pressure is adjusted by changing the torque of the generator 22 connected to the sub-expander 23 (that is, the load of the generator) to flow into the expander 6. The amount of refrigerant can be controlled. Therefore, power can be recovered efficiently in the expander 6, and higher power can be recovered from the refrigeration cycle by using the power recovered from the sub-expander 23 for power generation by the generator 24.

Hereinafter, a refrigeration cycle apparatus according to another embodiment of the present invention will be described with reference to the drawings for a heat pump type air conditioning apparatus.
FIG. 27 is a configuration diagram of a heat pump air-conditioning type air conditioner according to the present embodiment.
As shown in the figure, the heat pump type air conditioning apparatus according to the present embodiment uses a CO ₂ refrigerant as a refrigerant, a compressor 1 having a motor 12, an auxiliary compressor 10, an outdoor heat exchanger 3, and The expander 6 and the indoor heat exchanger 8 are configured by a refrigerant circuit connected by piping.
A sub expander 23 is provided on the discharge side of the expander 6, and a generator 24 is connected to the drive shaft of the sub expander 23.
Further, the drive shaft of the expander 6 and the drive shaft of the auxiliary compressor 10 are connected, and the auxiliary compressor 10 is driven by the power recovered by the expander 6.
The refrigerant circuit includes a first four-way valve 2 to which a suction side pipe of the compressor 1 and a discharge side pipe of the auxiliary compressor 10 are connected, a discharge side pipe of the sub expander 23, and a suction side of the expander 6. And a second four-way valve 4 connected to the pipe.

The operation of the heat pump type air conditioning apparatus according to this embodiment will be described below.
First, the cooling operation mode using the outdoor heat exchanger 3 as a radiator and the indoor heat exchanger 8 as an evaporator will be described. The refrigerant flow in the cooling operation mode is indicated by solid line arrows in the figure.
The refrigerant in the cooling operation mode is compressed and discharged at a high temperature and a high pressure by the compressor 1 driven by the motor 12, guided to the auxiliary compressor 10, and further overpressure (expressor) by the auxiliary compressor 10. Then, it is introduced into the outdoor heat exchanger 3 through the first four-way valve 2. In the outdoor heat exchanger 3, since the CO ₂ refrigerant is in a supercritical state, it does not enter a gas-liquid two-phase state but radiates heat to an external fluid such as air or water. Thereafter, the CO ₂ refrigerant is introduced into the expander 6 and the sub expander 23 through the second four-way valve 4, and is decompressed by the expander 6 and the sub expander 23. The power recovered by the expander 6 during this decompression is used to drive the auxiliary compressor 10. At this time, for example, the optimum refrigerant amount flowing to the expander 6 is calculated from the high-pressure refrigerant temperature and the high-pressure refrigerant pressure detected on the outlet side of the outdoor heat exchanger 3, and power generation is performed when the volume flow rate is smaller than the calculated optimum refrigerant amount. The volume flow rate flowing into the expander 6 is increased by increasing the torque (generator load) of the machine 22 and lowering the low pressure side pressure. Further, when the optimum refrigerant amount flowing through the expander 6 is larger than the calculated optimum refrigerant amount, the volume flow rate flowing into the expander 6 by decreasing the torque (generator load) of the generator 22 and increasing the low-pressure side pressure. Decrease.
The CO ₂ refrigerant decompressed by the expander 6 and the sub-expander 23 is guided to the indoor heat exchanger 8 via the second four-way valve 4 and is evaporated and absorbs heat by the indoor heat exchanger 8. . Indoor cooling is performed by this heat absorption. The evaporated refrigerant is sucked into the compressor 1 through the first four-way valve 2.

Next, a heating operation mode using the outdoor heat exchanger 3 as an evaporator and the indoor heat exchanger 8 as a radiator will be described. The refrigerant flow in the heating operation mode is indicated by a wavy arrow in the figure.
The refrigerant in the heating operation mode is compressed and discharged at a high temperature and high pressure by the compressor 1 driven by the motor 12, guided to the auxiliary compressor 10, and further overpressure (expressor) by the auxiliary compressor 10. Then, it is introduced into the indoor heat exchanger 8 through the first four-way valve 2. In the indoor heat exchanger 8, since the CO ₂ refrigerant is in a supercritical state, the CO ₂ refrigerant does not enter a gas-liquid two-phase state but radiates heat to an external fluid such as air or water. Heating is performed. Thereafter, the CO ₂ refrigerant is introduced into the expander 6 and the sub expander 23 through the second four-way valve 4, and is decompressed by the expander 6 and the sub expander 23. The power recovered by the expander 6 during this decompression is used to drive the auxiliary compressor 10. At this time, for example, the optimum refrigerant amount flowing to the expander 6 is calculated from the high-pressure refrigerant temperature and the high-pressure refrigerant pressure detected at the outlet side of the indoor heat exchanger 8, and power generation is performed when the volume flow rate is smaller than the calculated optimum refrigerant amount. The volume flow rate flowing into the expander 6 is increased by increasing the torque (generator load) of the machine 22 and lowering the low pressure side pressure. Further, when the optimum refrigerant amount flowing through the expander 6 is larger than the calculated optimum refrigerant amount, the volume flow rate flowing into the expander 6 by decreasing the torque (generator load) of the generator 22 and increasing the low-pressure side pressure. Decrease.
The CO ₂ refrigerant depressurized by the expander 6 and the sub-expander 23 evaporates and absorbs heat in the outdoor heat exchanger 3, and the refrigerant that has finished evaporating passes through the first four-way valve 2 to compress the compressor 1. Inhaled.

  As described above, according to the present embodiment, the low-pressure side pressure is adjusted by changing the torque of the generator 22 connected to the sub-expander 23 (that is, the load of the generator) to flow into the expander 6. The amount of refrigerant can be controlled. Therefore, power can be recovered efficiently in the expander 6, and higher power can be recovered from the refrigeration cycle by using the power recovered from the sub-expander 23 for power generation by the generator 24.

Hereinafter, a refrigeration cycle apparatus according to another embodiment of the present invention will be described with reference to the drawings for a heat pump type air conditioning apparatus.
FIG. 28 is a configuration diagram of a heat pump type air conditioning apparatus according to the present embodiment.
As shown in the figure, the heat pump air-conditioning type air conditioner according to the present embodiment uses a CO ₂ refrigerant as a refrigerant, a compressor 1 having a motor 12, an outdoor heat exchanger 3, an expander 6, It is comprised from the refrigerant circuit which connected the indoor side heat exchanger 8 and the auxiliary compressor 10 with piping.
A sub expander 23 is provided on the inflow side of the expander 6, and a generator 24 is connected to a drive shaft of the sub expander 23.
A bypass circuit that bypasses the sub-expander 23 and the expander 6 is provided in parallel with the sub-expander 23 and the expander 6, and the sub-expander 21 is provided in the bypass circuit, and the drive shaft of the sub-expander 21 Is connected to a generator 22. This bypass circuit is also connected to the second four-way valve 4 in the same manner as the sub-expander 23 and the expander 6.
Further, the drive shaft of the expander 6 and the drive shaft of the auxiliary compressor 10 are connected, and the auxiliary compressor 10 is driven by the power recovered by the expander 6.
The refrigerant circuit includes a first four-way valve 2 to which a discharge side pipe of the compressor 1 and a suction side pipe of the auxiliary compressor 10 are connected, a suction side pipe of the sub expander 23, and a discharge side of the expander 6. A pipe is connected, and a second four-way valve 4 to which a bypass circuit is connected is provided.

The operation of the heat pump type air conditioning apparatus according to this embodiment will be described below.
First, the cooling operation mode using the outdoor heat exchanger 3 as a radiator and the indoor heat exchanger 8 as an evaporator will be described. The refrigerant flow in the cooling operation mode is indicated by solid line arrows in the figure.
The refrigerant in the cooling operation mode is compressed and discharged at a high temperature and a high pressure by the compressor 1 driven by the motor 12, and is introduced into the outdoor heat exchanger 3 through the first four-way valve 2. In the outdoor heat exchanger 3, since the CO ₂ refrigerant is in a supercritical state, it does not enter a gas-liquid two-phase state but radiates heat to an external fluid such as air or water. Thereafter, the CO ₂ refrigerant is introduced into the sub expander 23, the expander 6, and the sub expander 21, and decompressed by the sub expander 23, the expander 6, and the sub expander 21. The power recovered by the expander 6 during this decompression is used to drive the auxiliary compressor 10. At this time, for example, the optimum refrigerant amount flowing to the expander 6 is calculated from the high-pressure refrigerant temperature and the high-pressure refrigerant pressure detected at the outlet side of the outdoor heat exchanger 3, and when the volume flow rate is larger than the calculated optimum refrigerant amount The volume flow rate flowing into the expander 6 is decreased by decreasing the torque (generator load) of the machine 22 and increasing the amount of refrigerant flowing through the bypass circuit. On the other hand, when the volume flow rate is smaller than the calculated optimum refrigerant amount, the volume flow rate flowing into the expander 6 is increased by increasing the torque (generator load) of the generator 24 and increasing the high-pressure side pressure.
CO ₂ refrigerant decompressed by the sub-expander 23 and the expander 6 CO reduced in pressure by _second refrigerant or sub expander 21 is guided to the indoor heat exchanger 8 through the second four-way valve 4, It evaporates and absorbs heat in the indoor heat exchanger 8. Indoor cooling is performed by this heat absorption. The evaporated refrigerant is guided to the auxiliary compressor 10 through the first four-way valve 2, supercharged (charged) by the auxiliary compressor 10, and sucked into the compressor 1.

Next, a heating operation mode using the outdoor heat exchanger 3 as an evaporator and the indoor heat exchanger 8 as a radiator will be described. The refrigerant flow in the heating operation mode is indicated by a wavy arrow in the figure.
The refrigerant in the heating operation mode is compressed and discharged at a high temperature and high pressure by the compressor 1 driven by the motor 12, and is introduced into the indoor heat exchanger 8 through the first four-way valve 2. In the indoor heat exchanger 8, since the CO ₂ refrigerant is in a supercritical state, the CO ₂ refrigerant does not enter a gas-liquid two-phase state but radiates heat to an external fluid such as air or water. Heating is performed. Thereafter, the CO ₂ refrigerant is introduced into the sub expander 23, the expander 6, and the sub expander 21, and decompressed by the sub expander 23, the expander 6, and the sub expander 21. The power recovered by the expander 6 during this decompression is used to drive the auxiliary compressor 10. At this time, for example, the optimum refrigerant amount flowing to the expander 6 is calculated from the high-pressure refrigerant temperature and the high-pressure refrigerant pressure detected on the outlet side of the indoor heat exchanger 8, and power generation is performed when the volume flow rate is larger than the calculated optimum refrigerant amount. The volume flow rate flowing into the expander 6 is decreased by decreasing the torque (generator load) of the machine 22 and increasing the amount of refrigerant flowing through the bypass circuit. On the other hand, when the volume flow rate is smaller than the calculated optimum refrigerant amount, the volume flow rate flowing into the expander 6 is increased by increasing the torque (generator load) of the generator 24 and increasing the high-pressure side pressure.
CO ₂ refrigerant decompressed by the sub-expander 23 and the expander 6 CO reduced in pressure by _second refrigerant or sub expander 21 is guided to the outdoor heat exchanger 3 through the second four-way valve 4, The refrigerant that evaporates and absorbs heat in the outdoor heat exchanger 3 and is evaporated is led to the auxiliary compressor 10 through the first four-way valve 2, and is supercharged (charged) by the auxiliary compressor 10. 1 is inhaled.

  As described above, according to the present embodiment, the expander is configured by adjusting the amount of refrigerant flowing through the bypass circuit by changing the torque of the generator 22 connected to the sub expander 21 (that is, the load of the generator). The amount of refrigerant flowing through the sub-expander 23 can be controlled, while the high-pressure side pressure is adjusted by changing the torque of the generator 24 connected to the sub-expander 23 (ie, the load of the generator). It is possible to control the amount of refrigerant flowing in the tank. Therefore, power can be efficiently recovered in the expander 6, and the power recovered from the sub-expander 21 and the sub-expander 23 is used for power generation by the generator 22 and the generator 24. Power recovery can be performed.

Hereinafter, a refrigeration cycle apparatus according to another embodiment of the present invention will be described with reference to the drawings for a heat pump type air conditioning apparatus.
FIG. 29 is a configuration diagram of a heat pump type air conditioning apparatus according to the present embodiment.
As shown in the figure, the heat pump type air conditioning apparatus according to the present embodiment uses a CO ₂ refrigerant as a refrigerant, a compressor 1 having a motor 12, an auxiliary compressor 10, an outdoor heat exchanger 3, and The expander 6 and the indoor heat exchanger 8 are configured by a refrigerant circuit connected by piping.
A sub expander 23 is provided on the inflow side of the expander 6, and a generator 24 is connected to a drive shaft of the sub expander 23.
A bypass circuit that bypasses the sub-expander 23 and the expander 6 is provided in parallel with the sub-expander 23 and the expander 6, and the sub-expander 21 is provided in the bypass circuit, and the drive shaft of the sub-expander 21 Is connected to a generator 22. This bypass circuit is also connected to the second four-way valve 4 in the same manner as the sub-expander 23 and the expander 6.
Further, the drive shaft of the expander 6 and the drive shaft of the auxiliary compressor 10 are connected, and the auxiliary compressor 10 is driven by the power recovered by the expander 6.
The refrigerant circuit includes a first four-way valve 2 to which a suction side pipe of the compressor 1 and a discharge side pipe of the auxiliary compressor 10 are connected, a suction side pipe of the sub expander 23, and a discharge side of the expander 6. A pipe is connected, and a second four-way valve 4 to which a bypass circuit is connected is provided.

The operation of the heat pump type air conditioning apparatus according to this embodiment will be described below.
First, the cooling operation mode using the outdoor heat exchanger 3 as a radiator and the indoor heat exchanger 8 as an evaporator will be described. The refrigerant flow in the cooling operation mode is indicated by solid line arrows in the figure.
The refrigerant in the cooling operation mode is compressed and discharged at a high temperature and a high pressure by the compressor 1 driven by the motor 12, guided to the auxiliary compressor 10, and further overpressure (expressor) by the auxiliary compressor 10. Then, it is introduced into the outdoor heat exchanger 3 through the first four-way valve 2. In the outdoor heat exchanger 3, since the CO ₂ refrigerant is in a supercritical state, it does not enter a gas-liquid two-phase state but radiates heat to an external fluid such as air or water. Thereafter, the CO ₂ refrigerant is introduced into the sub expander 23, the expander 6, and the sub expander 21, and decompressed by the sub expander 23, the expander 6, and the sub expander 21. The power recovered by the expander 6 during this decompression is used to drive the auxiliary compressor 10. At this time, for example, the optimum refrigerant amount flowing to the expander 6 is calculated from the high-pressure refrigerant temperature and the high-pressure refrigerant pressure detected at the outlet side of the outdoor heat exchanger 3, and when the volume flow rate is larger than the calculated optimum refrigerant amount The volume flow rate flowing into the expander 6 is decreased by decreasing the torque (generator load) of the machine 22 and increasing the amount of refrigerant flowing through the bypass circuit. On the other hand, when the volume flow rate is smaller than the calculated optimum refrigerant amount, the volume flow rate flowing into the expander 6 is increased by increasing the torque (generator load) of the generator 24 and increasing the high-pressure side pressure.
CO ₂ refrigerant decompressed by the sub-expander 23 and the expander 6 CO reduced in pressure by _second refrigerant or sub expander 21 is guided to the indoor heat exchanger 8 through the second four-way valve 4, It evaporates and absorbs heat in the indoor heat exchanger 8. Indoor cooling is performed by this heat absorption. The evaporated refrigerant is sucked into the compressor 1 through the first four-way valve 2.

Next, a heating operation mode using the outdoor heat exchanger 3 as an evaporator and the indoor heat exchanger 8 as a radiator will be described. The refrigerant flow in the heating operation mode is indicated by a wavy arrow in the figure.
The refrigerant in the heating operation mode is compressed and discharged at a high temperature and high pressure by the compressor 1 driven by the motor 12, guided to the auxiliary compressor 10, and further overpressure (expressor) by the auxiliary compressor 10. Then, it is introduced into the indoor heat exchanger 8 through the first four-way valve 2. In the indoor heat exchanger 8, since the CO ₂ refrigerant is in a supercritical state, the CO ₂ refrigerant does not enter a gas-liquid two-phase state but radiates heat to an external fluid such as air or water. Heating is performed. Thereafter, the CO ₂ refrigerant is introduced into the sub expander 23, the expander 6, and the sub expander 21, and decompressed by the sub expander 23, the expander 6, and the sub expander 21. The power recovered by the expander 6 during this decompression is used to drive the auxiliary compressor 10. At this time, for example, the optimum refrigerant amount flowing to the expander 6 is calculated from the high-pressure refrigerant temperature and the high-pressure refrigerant pressure detected on the outlet side of the indoor heat exchanger 8, and power generation is performed when the volume flow rate is larger than the calculated optimum refrigerant amount. The volume flow rate flowing into the expander 6 is decreased by decreasing the torque (generator load) of the machine 22 and increasing the amount of refrigerant flowing through the bypass circuit. On the other hand, when the volume flow rate is smaller than the calculated optimum refrigerant amount, the volume flow rate flowing into the expander 6 is increased by increasing the torque (generator load) of the generator 24 and increasing the high-pressure side pressure.
CO ₂ refrigerant decompressed by the sub-expander 23 and the expander 6 CO reduced in pressure by _second refrigerant or sub expander 21 is guided to the outdoor heat exchanger 3 through the second four-way valve 4, The refrigerant that has evaporated and absorbed heat in the outdoor heat exchanger 3 and has finished evaporation is sucked into the compressor 1 via the first four-way valve 2.

  As described above, according to the present embodiment, the expander is configured by adjusting the amount of refrigerant flowing through the bypass circuit by changing the torque of the generator 22 connected to the sub expander 21 (that is, the load of the generator). The amount of refrigerant flowing through the sub-expander 23 can be controlled, while the high-pressure side pressure is adjusted by changing the torque of the generator 24 connected to the sub-expander 23 (ie, the load of the generator). It is possible to control the amount of refrigerant flowing in the tank. Therefore, power can be efficiently recovered in the expander 6, and the power recovered from the sub-expander 21 and the sub-expander 23 is used for power generation by the generator 22 and the generator 24. Power recovery can be performed.

Hereinafter, a refrigeration cycle apparatus according to another embodiment of the present invention will be described with reference to the drawings for a heat pump type air conditioning apparatus.
FIG. 30 is a configuration diagram of a heat pump air-conditioning type air conditioner according to the present embodiment.
As shown in the figure, the heat pump air-conditioning type air conditioner according to the present embodiment uses a CO ₂ refrigerant as a refrigerant, a compressor 1 having a motor 12, an outdoor heat exchanger 3, an expander 6, It is comprised from the refrigerant circuit which connected the indoor side heat exchanger 8 and the auxiliary compressor 10 with piping.
A sub expander 23 is provided on the inflow side of the expander 6, and a generator 24 is connected to a drive shaft of the sub expander 23.
A bypass circuit that bypasses the sub-expander 23 and the expander 6 is provided in parallel with the sub-expander 23 and the expander 6, and a bypass valve 7 is provided in the bypass circuit. This bypass circuit is also connected to the second four-way valve 4 in the same manner as the sub-expander 23 and the expander 6.
Further, the drive shaft of the expander 6 and the drive shaft of the auxiliary compressor 10 are connected, and the auxiliary compressor 10 is driven by the power recovered by the expander 6.
The refrigerant circuit includes a first four-way valve 2 to which a discharge side pipe of the compressor 1 and a suction side pipe of the auxiliary compressor 10 are connected, a suction side pipe of the sub expander 23, and a discharge side of the expander 6. And a second four-way valve 4 to which a bypass circuit is connected.

The operation of the heat pump type air conditioning apparatus according to this embodiment will be described below.
First, the cooling operation mode using the outdoor heat exchanger 3 as a radiator and the indoor heat exchanger 8 as an evaporator will be described. The refrigerant flow in the cooling operation mode is indicated by solid line arrows in the figure.
The refrigerant in the cooling operation mode is compressed and discharged at a high temperature and a high pressure by the compressor 1 driven by the motor 12, and is introduced into the outdoor heat exchanger 3 through the first four-way valve 2. In the outdoor heat exchanger 3, since the CO ₂ refrigerant is in a supercritical state, it does not enter a gas-liquid two-phase state but radiates heat to an external fluid such as air or water. Thereafter, the CO ₂ refrigerant is introduced into the sub-expander 23 and the expander 6 and decompressed by the sub-expander 23 and the expander 6. The power recovered by the expander 6 during this decompression is used to drive the auxiliary compressor 10. At this time, for example, the optimum refrigerant amount flowing to the expander 6 is calculated from the high-pressure refrigerant temperature and the high-pressure refrigerant pressure detected at the outlet side of the outdoor heat exchanger 3, and when the volume flow rate is larger than the calculated optimum refrigerant amount, bypass is performed. By increasing the opening of the valve 7 and increasing the amount of refrigerant flowing through the bypass circuit, the volume flow rate flowing into the expander 6 is decreased. On the other hand, when the volume flow rate is smaller than the calculated optimum refrigerant amount, the volume flow rate flowing into the expander 6 is increased by increasing the torque (generator load) of the generator 24 and increasing the high-pressure side pressure.
The CO ₂ refrigerant decompressed by the sub-expander 23 and the expander 6 is guided to the indoor heat exchanger 8 via the second four-way valve 4 and is evaporated and absorbs heat in the indoor heat exchanger 8. . Indoor cooling is performed by this heat absorption. The evaporated refrigerant is led to the auxiliary compressor 10 through the first four-way valve 2, supercharged (charged) by the auxiliary compressor 10, and sucked into the compressor 1.

Next, a heating operation mode using the outdoor heat exchanger 3 as an evaporator and the indoor heat exchanger 8 as a radiator will be described. The refrigerant flow in the heating operation mode is indicated by a wavy arrow in the figure.
The refrigerant in the heating operation mode is compressed and discharged at a high temperature and high pressure by the compressor 1 driven by the motor 12, and is introduced into the indoor heat exchanger 8 through the first four-way valve 2. In the indoor heat exchanger 8, since the CO ₂ refrigerant is in a supercritical state, the CO ₂ refrigerant does not enter a gas-liquid two-phase state but radiates heat to an external fluid such as air or water. Heating is performed. Thereafter, the CO ₂ refrigerant is introduced into the sub-expander 23 and the expander 6 and decompressed by the sub-expander 23 and the expander 6. The power recovered by the expander 6 during this decompression is used to drive the auxiliary compressor 10. At this time, for example, the optimum refrigerant amount flowing to the expander 6 is calculated from the high-pressure refrigerant temperature and the high-pressure refrigerant pressure detected at the outlet side of the indoor heat exchanger 8, and when the volume flow rate is larger than the calculated optimum refrigerant amount, bypass is performed. By increasing the opening of the valve 7 and increasing the amount of refrigerant flowing through the bypass circuit, the volume flow rate flowing into the expander 6 is decreased. On the other hand, when the volume flow rate is smaller than the calculated optimum refrigerant amount, the volume flow rate flowing into the expander 6 is increased by increasing the torque (generator load) of the generator 24 and increasing the high-pressure side pressure.
The CO ₂ refrigerant decompressed by the sub-expander 23 and the expander 6 is guided to the outdoor heat exchanger 3 via the second four-way valve 4 and is evaporated and absorbs heat in the outdoor heat exchanger 3. The evaporated refrigerant is guided to the auxiliary compressor 10 via the first four-way valve 2, supercharged (charged) by the auxiliary compressor 10, and sucked into the compressor 1.

  As described above, according to this embodiment, the amount of refrigerant flowing through the expander 6 can be controlled by adjusting the amount of refrigerant flowing through the bypass circuit by changing the opening of the bypass valve 7. The amount of refrigerant flowing through the expander 6 can be controlled by changing the torque of the generator 24 connected to the sub-expander 23 (that is, the load of the generator) to adjust the high-pressure side pressure. Therefore, power can be recovered efficiently in the expander 6, and higher power can be recovered from the refrigeration cycle by using the power recovered from the sub-expander 23 for power generation by the generator 24.

Hereinafter, a refrigeration cycle apparatus according to another embodiment of the present invention will be described with reference to the drawings for a heat pump type air conditioning apparatus.
FIG. 31 is a configuration diagram of a heat pump type air conditioning apparatus according to the present embodiment.
As shown in the figure, the heat pump type air conditioning apparatus according to the present embodiment uses a CO ₂ refrigerant as a refrigerant, a compressor 1 having a motor 12, an auxiliary compressor 10, an outdoor heat exchanger 3, and The expander 6 and the indoor heat exchanger 8 are configured by a refrigerant circuit connected by piping.
A sub expander 23 is provided on the inflow side of the expander 6, and a generator 24 is connected to a drive shaft of the sub expander 23.
A bypass circuit that bypasses the sub-expander 23 and the expander 6 is provided in parallel with the sub-expander 23 and the expander 6, and a bypass valve 7 is provided in the bypass circuit. This bypass circuit is also connected to the second four-way valve 4 in the same manner as the sub-expander 23 and the expander 6.
Further, the drive shaft of the expander 6 and the drive shaft of the auxiliary compressor 10 are connected, and the auxiliary compressor 10 is driven by the power recovered by the expander 6.
The refrigerant circuit includes a first four-way valve 2 to which a suction side pipe of the compressor 1 and a discharge side pipe of the auxiliary compressor 10 are connected, a suction side pipe of the sub expander 23, and a discharge side of the expander 6. And a second four-way valve 4 to which a bypass circuit is connected.

The operation of the heat pump type air conditioning apparatus according to this embodiment will be described below.
First, the cooling operation mode using the outdoor heat exchanger 3 as a radiator and the indoor heat exchanger 8 as an evaporator will be described. The refrigerant flow in the cooling operation mode is indicated by solid line arrows in the figure.
The refrigerant in the cooling operation mode is compressed and discharged at a high temperature and a high pressure by the compressor 1 driven by the motor 12, guided to the auxiliary compressor 10, and further overpressure (expressor) by the auxiliary compressor 10. Then, it is introduced into the outdoor heat exchanger 3 through the first four-way valve 2. In the outdoor heat exchanger 3, since the CO ₂ refrigerant is in a supercritical state, it does not enter a gas-liquid two-phase state but radiates heat to an external fluid such as air or water. Thereafter, the CO ₂ refrigerant is introduced into the sub-expander 23 and the expander 6 and decompressed by the sub-expander 23 and the expander 6. The power recovered by the expander 6 during this decompression is used to drive the auxiliary compressor 10. At this time, for example, the optimum refrigerant amount flowing to the expander 6 is calculated from the high-pressure refrigerant temperature and the high-pressure refrigerant pressure detected at the outlet side of the outdoor heat exchanger 3, and when the volume flow rate is larger than the calculated optimum refrigerant amount, bypass is performed. By increasing the opening of the valve 7 and increasing the amount of refrigerant flowing through the bypass circuit, the volume flow rate flowing into the expander 6 is decreased. On the other hand, when the volume flow rate is smaller than the calculated optimum refrigerant amount, the volume flow rate flowing into the expander 6 is increased by increasing the torque (generator load) of the generator 24 and increasing the high-pressure side pressure.
The CO ₂ refrigerant decompressed by the sub-expander 23 and the expander 6 is guided to the indoor heat exchanger 8 via the second four-way valve 4 and is evaporated and absorbs heat in the indoor heat exchanger 8. . Indoor cooling is performed by this heat absorption. The evaporated refrigerant is sucked into the compressor 1 through the first four-way valve 2.

Next, a heating operation mode using the outdoor heat exchanger 3 as an evaporator and the indoor heat exchanger 8 as a radiator will be described. The refrigerant flow in the heating operation mode is indicated by a wavy arrow in the figure.
The refrigerant in the heating operation mode is compressed and discharged at a high temperature and high pressure by the compressor 1 driven by the motor 12, guided to the auxiliary compressor 10, and further overpressure (expressor) by the auxiliary compressor 10. Then, it is introduced into the indoor heat exchanger 8 through the first four-way valve 2. In the indoor heat exchanger 8, since the CO ₂ refrigerant is in a supercritical state, the CO ₂ refrigerant does not enter a gas-liquid two-phase state but radiates heat to an external fluid such as air or water. Heating is performed. Thereafter, the CO ₂ refrigerant is introduced into the sub-expander 23 and the expander 6 and decompressed by the sub-expander 23 and the expander 6. The power recovered by the expander 6 during this decompression is used to drive the auxiliary compressor 10. At this time, for example, the optimum refrigerant amount flowing to the expander 6 is calculated from the high-pressure refrigerant temperature and the high-pressure refrigerant pressure detected at the outlet side of the indoor heat exchanger 8, and when the volume flow rate is larger than the calculated optimum refrigerant amount, bypass is performed. By increasing the opening of the valve 7 and increasing the amount of refrigerant flowing through the bypass circuit, the volume flow rate flowing into the expander 6 is decreased. On the other hand, when the volume flow rate is smaller than the calculated optimum refrigerant amount, the volume flow rate flowing into the expander 6 is increased by increasing the torque (generator load) of the generator 24 and increasing the high-pressure side pressure.
The CO ₂ refrigerant decompressed by the sub-expander 23 and the expander 6 is guided to the outdoor heat exchanger 3 via the second four-way valve 4 and is evaporated and absorbs heat in the outdoor heat exchanger 3. The evaporated refrigerant is sucked into the compressor 1 via the first four-way valve 2.

  As described above, according to this embodiment, the amount of refrigerant flowing through the expander 6 can be controlled by adjusting the amount of refrigerant flowing through the bypass circuit by changing the opening of the bypass valve 7. The amount of refrigerant flowing through the expander 6 can be controlled by changing the torque of the generator 24 connected to the sub-expander 23 (that is, the load of the generator) to adjust the high-pressure side pressure. Therefore, power can be recovered efficiently in the expander 6, and higher power can be recovered from the refrigeration cycle by using the power recovered from the sub-expander 23 for power generation by the generator 24.

Hereinafter, a refrigeration cycle apparatus according to another embodiment of the present invention will be described with reference to the drawings for a heat pump type air conditioning apparatus.
FIG. 32 is a configuration diagram of a heat pump air-conditioning type air conditioner according to the present embodiment.
As shown in the figure, the heat pump air-conditioning type air conditioner according to the present embodiment uses a CO ₂ refrigerant as a refrigerant, a compressor 1 having a motor 12, an outdoor heat exchanger 3, an expander 6, It is comprised from the refrigerant circuit which connected the indoor side heat exchanger 8 and the auxiliary compressor 10 with piping.
A pre-expansion valve 5 is provided on the inflow side of the expander 6.
A bypass circuit for bypassing the pre-expansion valve 5 and the expander 6 is provided in parallel with the pre-expansion valve 5 and the expander 6, and a sub-expander is provided in the bypass circuit. Is connected to a generator 22. This bypass circuit is also connected to the second four-way valve 4 in the same manner as the sub-expander 23 and the expander 6.
Further, the drive shaft of the expander 6 and the drive shaft of the auxiliary compressor 10 are connected, and the auxiliary compressor 10 is driven by the power recovered by the expander 6.
The refrigerant circuit includes a first four-way valve 2 to which a discharge side pipe of the compressor 1 and a suction side pipe of the auxiliary compressor 10 are connected, a suction side pipe of the pre-expansion valve 5 and a discharge side of the expander 6. And a second four-way valve 4 to which a bypass circuit is connected.

The operation of the heat pump type air conditioning apparatus according to this embodiment will be described below.
First, the cooling operation mode using the outdoor heat exchanger 3 as a radiator and the indoor heat exchanger 8 as an evaporator will be described. The refrigerant flow in the cooling operation mode is indicated by solid line arrows in the figure.
The refrigerant in the cooling operation mode is compressed and discharged at a high temperature and a high pressure by the compressor 1 driven by the motor 12, and is introduced into the outdoor heat exchanger 3 through the first four-way valve 2. In the outdoor heat exchanger 3, since the CO ₂ refrigerant is in a supercritical state, it does not enter a gas-liquid two-phase state but radiates heat to an external fluid such as air or water. Thereafter, the CO ₂ refrigerant is introduced into the pre-expansion valve 5, the expander 6, and the sub-expander 21, and decompressed by the pre-expansion valve 5, the expander 6, and the sub-expander 21. The power recovered by the expander 6 during this decompression is used to drive the auxiliary compressor 10. At this time, for example, the optimum refrigerant amount flowing to the expander 6 is calculated from the high-pressure refrigerant temperature and the high-pressure refrigerant pressure detected at the outlet side of the outdoor heat exchanger 3, and when the volume flow rate is larger than the calculated optimum refrigerant amount The volume flow rate flowing into the expander 6 is decreased by decreasing the torque (generator load) of the machine 22 and increasing the amount of refrigerant flowing through the bypass circuit. On the other hand, when the volume flow rate is smaller than the calculated optimum refrigerant amount, the volume flow rate flowing into the expander 6 is increased by decreasing the opening of the pre-expansion valve 5 and increasing the high-pressure side pressure.
CO ₂ refrigerant decompressed by the pre-expansion valve 5 and the expander 6 CO ₂ refrigerant or sub expander 21 that is decompressed by is guided to the indoor heat exchanger 8 through the second four-way valve 4, It evaporates and absorbs heat in the indoor heat exchanger 8. Indoor cooling is performed by this heat absorption. The evaporated refrigerant is led to the auxiliary compressor 10 through the first four-way valve 2, supercharged (charged) by the auxiliary compressor 10, and sucked into the compressor 1.

Next, a heating operation mode using the outdoor heat exchanger 3 as an evaporator and the indoor heat exchanger 8 as a radiator will be described. The refrigerant flow in the heating operation mode is indicated by a wavy arrow in the figure.
The refrigerant in the heating operation mode is compressed and discharged at a high temperature and high pressure by the compressor 1 driven by the motor 12, and is introduced into the indoor heat exchanger 8 through the first four-way valve 2. In the indoor heat exchanger 8, since the CO ₂ refrigerant is in a supercritical state, the CO ₂ refrigerant does not enter a gas-liquid two-phase state but radiates heat to an external fluid such as air or water. Heating is performed. Thereafter, the CO ₂ refrigerant is introduced into the pre-expansion valve 5, the expander 6, and the sub-expander 21, and decompressed by the pre-expansion valve 5, the expander 6, and the sub-expander 21. The power recovered by the expander 6 during this decompression is used to drive the auxiliary compressor 10. At this time, for example, the optimum refrigerant amount flowing to the expander 6 is calculated from the high-pressure refrigerant temperature and the high-pressure refrigerant pressure detected on the outlet side of the indoor heat exchanger 8, and power generation is performed when the volume flow rate is larger than the calculated optimum refrigerant amount. The volume flow rate flowing into the expander 6 is decreased by decreasing the torque (generator load) of the machine 22 and increasing the amount of refrigerant flowing through the bypass circuit. On the other hand, when the volume flow rate is smaller than the calculated optimum refrigerant amount, the volume flow rate flowing into the expander 6 is increased by decreasing the opening of the pre-expansion valve 5 and increasing the high-pressure side pressure.
CO ₂ refrigerant decompressed by the pre-expansion valve 5 and the expander 6 CO reduced in pressure by _second refrigerant or sub expander 21 is guided to the outdoor heat exchanger 3 through the second four-way valve 4, The refrigerant that evaporates and absorbs heat in the outdoor heat exchanger 3 and is evaporated is led to the auxiliary compressor 10 via the first four-way valve 2 and is supercharged (charged) by the auxiliary compressor 10. 1 is inhaled.

  As described above, according to the present embodiment, the expander is configured by adjusting the amount of refrigerant flowing through the bypass circuit by changing the torque of the generator 22 connected to the sub expander 21 (that is, the load of the generator). The amount of refrigerant flowing to the expander 6 can be controlled by changing the opening of the pre-expansion valve 5 and adjusting the high-pressure side pressure. Therefore, power can be recovered efficiently in the expander 6 and higher power can be recovered from the refrigeration cycle by using the power recovered from the sub-expander 21 for power generation by the generator 22.

Hereinafter, a refrigeration cycle apparatus according to another embodiment of the present invention will be described with reference to the drawings for a heat pump type air conditioning apparatus.
FIG. 33 is a configuration diagram of a heat pump air-conditioning type air conditioner according to the present embodiment.
As shown in the figure, the heat pump type air conditioning apparatus according to the present embodiment uses a CO ₂ refrigerant as a refrigerant, a compressor 1 having a motor 12, an auxiliary compressor 10, an outdoor heat exchanger 3, and The expander 6 and the indoor heat exchanger 8 are configured by a refrigerant circuit connected by piping.
A pre-expansion valve 5 is provided on the inflow side of the expander 6.
A bypass circuit for bypassing the pre-expansion valve 5 and the expander 6 is provided in parallel with the pre-expansion valve 5 and the expander 6, and a sub-expander is provided in the bypass circuit. Is connected to a generator 22. This bypass circuit is also connected to the second four-way valve 4 in the same manner as the sub-expander 23 and the expander 6.
Further, the drive shaft of the expander 6 and the drive shaft of the auxiliary compressor 10 are connected, and the auxiliary compressor 10 is driven by the power recovered by the expander 6.
The refrigerant circuit includes a first four-way valve 2 to which a suction side pipe of the compressor 1 and a discharge side pipe of the auxiliary compressor 10 are connected, a suction side pipe of the pre-expansion valve 5 and a discharge side of the expander 6. And a second four-way valve 4 to which a bypass circuit is connected.

The operation of the heat pump type air conditioning apparatus according to this embodiment will be described below.
First, the cooling operation mode using the outdoor heat exchanger 3 as a radiator and the indoor heat exchanger 8 as an evaporator will be described. The refrigerant flow in the cooling operation mode is indicated by solid line arrows in the figure.
The refrigerant in the cooling operation mode is compressed and discharged at a high temperature and a high pressure by the compressor 1 driven by the motor 12, guided to the auxiliary compressor 10, and further overpressure (expressor) by the auxiliary compressor 10. Then, it is introduced into the outdoor heat exchanger 3 through the first four-way valve 2. In the outdoor heat exchanger 3, since the CO ₂ refrigerant is in a supercritical state, it does not enter a gas-liquid two-phase state but radiates heat to an external fluid such as air or water. Thereafter, the CO ₂ refrigerant is introduced into the pre-expansion valve 5, the expander 6, and the sub-expander 21, and decompressed by the pre-expansion valve 5, the expander 6, and the sub-expander 21. The power recovered by the expander 6 during this decompression is used to drive the auxiliary compressor 10. At this time, for example, the optimum refrigerant amount flowing to the expander 6 is calculated from the high-pressure refrigerant temperature and the high-pressure refrigerant pressure detected at the outlet side of the outdoor heat exchanger 3, and when the volume flow rate is larger than the calculated optimum refrigerant amount The volume flow rate flowing into the expander 6 is decreased by decreasing the torque (generator load) of the machine 22 and increasing the amount of refrigerant flowing through the bypass circuit. On the other hand, when the volume flow rate is smaller than the calculated optimum refrigerant amount, the volume flow rate flowing into the expander 6 is increased by decreasing the opening of the pre-expansion valve 5 and increasing the high-pressure side pressure.
CO ₂ refrigerant decompressed by the pre-expansion valve 5 and the expander 6 CO ₂ refrigerant or sub expander 21 that is decompressed by is guided to the indoor heat exchanger 8 through the second four-way valve 4, It evaporates and absorbs heat in the indoor heat exchanger 8. Indoor cooling is performed by this heat absorption. The evaporated refrigerant is sucked into the compressor 1 through the first four-way valve 2.

Next, a heating operation mode using the outdoor heat exchanger 3 as an evaporator and the indoor heat exchanger 8 as a radiator will be described. The refrigerant flow in the heating operation mode is indicated by a wavy arrow in the figure.
The refrigerant in the heating operation mode is compressed and discharged at a high temperature and high pressure by the compressor 1 driven by the motor 12, guided to the auxiliary compressor 10, and further overpressure (expressor) by the auxiliary compressor 10. Then, it is introduced into the indoor heat exchanger 8 through the first four-way valve 2. In the indoor heat exchanger 8, since the CO ₂ refrigerant is in a supercritical state, the CO ₂ refrigerant does not enter a gas-liquid two-phase state but radiates heat to an external fluid such as air or water. Heating is performed. Thereafter, the CO ₂ refrigerant is introduced into the pre-expansion valve 5, the expander 6, and the sub-expander 21, and decompressed by the pre-expansion valve 5, the expander 6, and the sub-expander 21. The power recovered by the expander 6 during this decompression is used to drive the auxiliary compressor 10. At this time, for example, the optimum refrigerant amount flowing to the expander 6 is calculated from the high-pressure refrigerant temperature and the high-pressure refrigerant pressure detected on the outlet side of the indoor heat exchanger 8, and power generation is performed when the volume flow rate is larger than the calculated optimum refrigerant amount. The volume flow rate flowing into the expander 6 is decreased by decreasing the torque (generator load) of the machine 22 and increasing the amount of refrigerant flowing through the bypass circuit. On the other hand, when the volume flow rate is smaller than the calculated optimum refrigerant amount, the volume flow rate flowing into the expander 6 is increased by decreasing the opening of the pre-expansion valve 5 and increasing the high-pressure side pressure.
CO ₂ refrigerant decompressed by the pre-expansion valve 5 and the expander 6 CO reduced in pressure by _second refrigerant or sub expander 21 is guided to the outdoor heat exchanger 3 through the second four-way valve 4, The refrigerant that has evaporated and absorbed heat in the outdoor heat exchanger 3 and has finished evaporation is sucked into the compressor 1 via the first four-way valve 2.

  As described above, according to the present embodiment, the expander is configured by adjusting the amount of refrigerant flowing through the bypass circuit by changing the torque of the generator 22 connected to the sub expander 21 (that is, the load of the generator). The amount of refrigerant flowing to the expander 6 can be controlled by changing the opening of the pre-expansion valve 5 and adjusting the high-pressure side pressure. Therefore, power can be recovered efficiently in the expander 6 and higher power can be recovered from the refrigeration cycle by using the power recovered from the sub-expander 21 for power generation by the generator 22.

Hereinafter, a refrigeration cycle apparatus according to another embodiment of the present invention will be described with reference to the drawings for a heat pump type air conditioning apparatus.
FIG. 34 is a configuration diagram of a heat pump air-conditioning type air conditioner according to the present embodiment.
As shown in the figure, the heat pump air-conditioning type air conditioner according to the present embodiment uses a CO ₂ refrigerant as a refrigerant, a compressor 1 having a motor 12, an outdoor heat exchanger 3, an expander 6, It is comprised from the refrigerant circuit which connected the indoor side heat exchanger 8 and the auxiliary compressor 10 with piping.
A sub expander 23 is provided on the inflow side of the expander 6, and a generator 22 is connected to a drive shaft of the sub expander 23.
A bypass circuit that bypasses the sub-expander 23 and the expander 6 is provided in parallel with the sub-expander 23 and the expander 6, and the sub-expander 21 is provided in the bypass circuit, and the drive shaft of the sub-expander 21 Is connected to a generator 22. This bypass circuit is also connected to the second four-way valve 4 in the same manner as the sub-expander 23 and the expander 6.
Here, the generator 22 includes a clutch mechanism connected to either the sub-expander 21 or the sub-expander 23. A flow path valve 25 is provided on the inflow side of the bypass circuit.
Further, the drive shaft of the expander 6 and the drive shaft of the auxiliary compressor 10 are connected, and the auxiliary compressor 10 is driven by the power recovered by the expander 6.
The refrigerant circuit includes a first four-way valve 2 to which a discharge side pipe of the compressor 1 and a suction side pipe of the auxiliary compressor 10 are connected, a suction side pipe of the sub expander 23, and a discharge side of the expander 6. And a second four-way valve 4 to which a bypass circuit is connected.

The operation of the heat pump type air conditioning apparatus according to this embodiment will be described below.
First, the cooling operation mode using the outdoor heat exchanger 3 as a radiator and the indoor heat exchanger 8 as an evaporator will be described. The refrigerant flow in the cooling operation mode is indicated by solid line arrows in the figure.
The refrigerant in the cooling operation mode is compressed and discharged at a high temperature and a high pressure by the compressor 1 driven by the motor 12, and is introduced into the outdoor heat exchanger 3 through the first four-way valve 2. In the outdoor heat exchanger 3, since the CO ₂ refrigerant is in a supercritical state, it does not enter a gas-liquid two-phase state but radiates heat to an external fluid such as air or water. Thereafter, the CO ₂ refrigerant is introduced into the sub-expander 23 and the expander 6 and decompressed by the sub-expander 23 and the expander 6. The power recovered by the expander 6 during this decompression is used to drive the auxiliary compressor 10. At this time, for example, the optimum refrigerant amount flowing to the expander 6 is calculated from the high-pressure refrigerant temperature and the high-pressure refrigerant pressure detected on the outlet side of the outdoor heat exchanger 3, and when the volume flow rate is larger than the calculated optimum refrigerant amount, The flow rate valve 25 is opened, the generator 22 is connected to the sub-expander 21 side, and the refrigerant flows through the bypass circuit to reduce the volume flow rate flowing into the expander 6. In this case, the sub expander 23 is not operated. Further, it is preferable to change the bypass amount by adjusting the torque of the generator 22. On the other hand, when the volume flow rate is smaller than the calculated optimum refrigerant amount, the flow path valve 25 is closed, the generator 22 is connected to the sub expander 23 side, and the high pressure side pressure is increased to flow into the expander 6. Increase volume flow. In this case, the sub expander 21 is not operated. It is preferable to change the high-pressure side pressure by adjusting the torque of the generator 22.
CO ₂ refrigerant decompressed by the sub-expander 23 and the expander 6, or the sub-expander 21 and CO ₂ refrigerant decompressed by the expander 6, an indoor heat exchanger through the second four-way valve 4 8 evaporates in the indoor heat exchanger 8 and absorbs heat. Indoor cooling is performed by this heat absorption. The evaporated refrigerant is led to the auxiliary compressor 10 through the first four-way valve 2, supercharged (charged) by the auxiliary compressor 10, and sucked into the compressor 1.

Next, a heating operation mode using the outdoor heat exchanger 3 as an evaporator and the indoor heat exchanger 8 as a radiator will be described. The refrigerant flow in the heating operation mode is indicated by a wavy arrow in the figure.
The refrigerant in the heating operation mode is compressed and discharged at a high temperature and high pressure by the compressor 1 driven by the motor 12, and is introduced into the indoor heat exchanger 8 through the first four-way valve 2. In the indoor heat exchanger 8, since the CO ₂ refrigerant is in a supercritical state, the CO ₂ refrigerant does not enter a gas-liquid two-phase state but radiates heat to an external fluid such as air or water. Heating is performed. Thereafter, the CO ₂ refrigerant is introduced into the sub-expander 23 and the expander 6 and decompressed by the sub-expander 23 and the expander 6. The power recovered by the expander 6 during this decompression is used to drive the auxiliary compressor 10. At this time, for example, the optimum refrigerant amount flowing to the expander 6 is calculated from the high-pressure refrigerant temperature and the high-pressure refrigerant pressure detected at the outlet side of the indoor heat exchanger 8, and when the volume flow rate is larger than the calculated optimum refrigerant amount, The flow rate valve 25 is opened, the generator 22 is connected to the sub-expander 21 side, and the refrigerant flows through the bypass circuit to reduce the volume flow rate flowing into the expander 6. In this case, the sub expander 23 is not operated. Further, it is preferable to change the bypass amount by adjusting the torque of the generator 22. On the other hand, when the volume flow rate is smaller than the calculated optimum refrigerant amount, the flow path valve 25 is closed, the generator 22 is connected to the sub expander 23 side, and the high pressure side pressure is increased to flow into the expander 6. Increase volume flow. In this case, the sub expander 21 is not operated. It is preferable to change the high-pressure side pressure by adjusting the torque of the generator 22.
CO ₂ refrigerant decompressed by the sub-expander 23 and the expander 6, or the sub-expander 21 and CO ₂ refrigerant decompressed by the expander 6, an outdoor heat exchanger via the second four-way valve 4 3, the refrigerant that has evaporated and absorbed heat in the outdoor heat exchanger 3 and has been evaporated is led to the auxiliary compressor 10 via the first four-way valve 2 and is supercharged by the auxiliary compressor 10 ( And is sucked into the compressor 1.

  As described above, according to the present embodiment, the amount of refrigerant flowing through the expander 6 is adjusted by adjusting the amount of refrigerant flowing through the bypass circuit by opening the on-off valve 25 and connecting the generator 22 to the sub-expander 21. On the other hand, by adjusting the high-pressure side pressure by changing the torque of the generator 24 connected to the sub-expander 23 (ie, the load of the generator) by closing the on-off valve 25, the expander 6 can be controlled. Accordingly, power can be efficiently recovered in the expander 6, and the power recovered from the sub-expander 21 or the sub-expander 23 is used for power generation by the generator 22 and the generator 24. Power recovery can be performed.

Hereinafter, a refrigeration cycle apparatus according to another embodiment of the present invention will be described with reference to the drawings for a heat pump type air conditioning apparatus.
FIG. 35 is a configuration diagram of a heat pump type air conditioning apparatus according to the present embodiment.
As shown in the figure, the heat pump type air conditioning apparatus according to the present embodiment uses a CO ₂ refrigerant as a refrigerant, a compressor 1 having a motor 12, an auxiliary compressor 10, an outdoor heat exchanger 3, and The expander 6 and the indoor heat exchanger 8 are configured by a refrigerant circuit connected by piping.
A sub expander 23 is provided on the inflow side of the expander 6, and a generator 22 is connected to a drive shaft of the sub expander 23.
A bypass circuit that bypasses the sub-expander 23 and the expander 6 is provided in parallel with the sub-expander 23 and the expander 6, and the sub-expander 21 is provided in the bypass circuit, and the drive shaft of the sub-expander 21 Is connected to a generator 22. This bypass circuit is also connected to the second four-way valve 4 in the same manner as the sub-expander 23 and the expander 6.
Here, the generator 22 includes a clutch mechanism connected to either the sub-expander 21 or the sub-expander 23. A flow path valve 25 is provided on the inflow side of the bypass circuit.
Further, the drive shaft of the expander 6 and the drive shaft of the auxiliary compressor 10 are connected, and the auxiliary compressor 10 is driven by the power recovered by the expander 6.
The refrigerant circuit includes a first four-way valve 2 to which a suction side pipe of the compressor 1 and a discharge side pipe of the auxiliary compressor 10 are connected, a suction side pipe of the sub expander 23, and a discharge side of the expander 6. And a second four-way valve 4 to which a bypass circuit is connected.

The operation of the heat pump type air conditioning apparatus according to this embodiment will be described below.
First, the cooling operation mode using the outdoor heat exchanger 3 as a radiator and the indoor heat exchanger 8 as an evaporator will be described. The refrigerant flow in the cooling operation mode is indicated by solid line arrows in the figure.
The refrigerant in the cooling operation mode is compressed and discharged at a high temperature and a high pressure by the compressor 1 driven by the motor 12, guided to the auxiliary compressor 10, and further overpressure (expressor) by the auxiliary compressor 10. Then, it is introduced into the outdoor heat exchanger 3 through the first four-way valve 2. In the outdoor heat exchanger 3, since the CO ₂ refrigerant is in a supercritical state, it does not enter a gas-liquid two-phase state but radiates heat to an external fluid such as air or water. Thereafter, the CO ₂ refrigerant is introduced into the sub-expander 23 and the expander 6 and decompressed by the sub-expander 23 and the expander 6. The power recovered by the expander 6 during this decompression is used to drive the auxiliary compressor 10. At this time, for example, the optimum refrigerant amount flowing to the expander 6 is calculated from the high-pressure refrigerant temperature and the high-pressure refrigerant pressure detected on the outlet side of the outdoor heat exchanger 3, and when the volume flow rate is larger than the calculated optimum refrigerant amount, The flow rate valve 25 is opened, the generator 22 is connected to the sub-expander 21 side, and the refrigerant flows through the bypass circuit to reduce the volume flow rate flowing into the expander 6. In this case, the sub expander 23 is not operated. Further, it is preferable to change the bypass amount by adjusting the torque of the generator 22. On the other hand, when the volume flow rate is smaller than the calculated optimum refrigerant amount, the flow path valve 25 is closed, the generator 22 is connected to the sub expander 23 side, and the high pressure side pressure is increased to flow into the expander 6. Increase volume flow. In this case, the sub expander 21 is not operated. It is preferable to change the high-pressure side pressure by adjusting the torque of the generator 22.
CO ₂ refrigerant decompressed by the sub-expander 23 and the expander 6, or the sub-expander 21 and CO ₂ refrigerant decompressed by the expander 6, an indoor heat exchanger through the second four-way valve 4 8 evaporates in the indoor heat exchanger 8 and absorbs heat. Indoor cooling is performed by this heat absorption. The evaporated refrigerant is sucked into the compressor 1 through the first four-way valve 2.

Next, a heating operation mode using the outdoor heat exchanger 3 as an evaporator and the indoor heat exchanger 8 as a radiator will be described. The refrigerant flow in the heating operation mode is indicated by a wavy arrow in the figure.
The refrigerant in the heating operation mode is compressed and discharged at a high temperature and high pressure by the compressor 1 driven by the motor 12, guided to the auxiliary compressor 10, and further overpressure (expressor) by the auxiliary compressor 10. Then, it is introduced into the indoor heat exchanger 8 through the first four-way valve 2. In the indoor heat exchanger 8, since the CO ₂ refrigerant is in a supercritical state, the CO ₂ refrigerant does not enter a gas-liquid two-phase state but radiates heat to an external fluid such as air or water. Heating is performed. Thereafter, the CO ₂ refrigerant is introduced into the sub-expander 23 and the expander 6 and decompressed by the sub-expander 23 and the expander 6. The power recovered by the expander 6 during this decompression is used to drive the auxiliary compressor 10. At this time, for example, the optimum refrigerant amount flowing to the expander 6 is calculated from the high-pressure refrigerant temperature and the high-pressure refrigerant pressure detected at the outlet side of the indoor heat exchanger 8, and when the volume flow rate is larger than the calculated optimum refrigerant amount, The flow rate valve 25 is opened, the generator 22 is connected to the sub-expander 21 side, and the refrigerant flows through the bypass circuit to reduce the volume flow rate flowing into the expander 6. In this case, the sub expander 23 is not operated. Further, it is preferable to change the bypass amount by adjusting the torque of the generator 22. On the other hand, when the volume flow rate is smaller than the calculated optimum refrigerant amount, the flow path valve 25 is closed, the generator 22 is connected to the sub expander 23 side, and the high pressure side pressure is increased to flow into the expander 6. Increase volume flow. In this case, the sub expander 21 is not operated. It is preferable to change the high-pressure side pressure by adjusting the torque of the generator 22.
CO ₂ refrigerant decompressed by the sub-expander 23 and the expander 6, or the sub-expander 21 and CO ₂ refrigerant decompressed by the expander 6, an outdoor heat exchanger via the second four-way valve 4 3, the refrigerant evaporating and absorbing heat in the outdoor heat exchanger 3, and the evaporated refrigerant is sucked into the compressor 1 through the first four-way valve 2.

  As described above, according to the present embodiment, the amount of refrigerant flowing through the expander 6 is adjusted by adjusting the amount of refrigerant flowing through the bypass circuit by opening the on-off valve 25 and connecting the generator 22 to the sub-expander 21. On the other hand, by adjusting the high-pressure side pressure by changing the torque of the generator 24 connected to the sub-expander 23 (ie, the load of the generator) by closing the on-off valve 25, the expander 6 can be controlled. Accordingly, power can be efficiently recovered in the expander 6, and the power recovered from the sub-expander 21 or the sub-expander 23 is used for power generation by the generator 22 and the generator 24. Power recovery can be performed.

Hereinafter, a refrigeration cycle apparatus according to another embodiment of the present invention will be described with reference to the drawings for a heat pump type air conditioning apparatus.
FIG. 36 is a configuration diagram of a heat pump air-conditioning type air conditioner according to the present embodiment.
As shown in the figure, the heat pump air-conditioning type air conditioner according to the present embodiment uses a CO ₂ refrigerant as a refrigerant, a compressor 1 having a motor 12, an outdoor heat exchanger 3, an expander 6, It is comprised from the refrigerant circuit which connected the indoor side heat exchanger 8 and the auxiliary compressor 10 with piping.
A sub-expander 23 is provided on the discharge side of the expander 6, and a generator 22 is connected to the drive shaft of the sub-expander 23.
A bypass circuit that bypasses the sub-expander 23 and the expander 6 is provided in parallel with the sub-expander 23 and the expander 6, and the sub-expander 21 is provided in the bypass circuit, and the drive shaft of the sub-expander 21 Is connected to a generator 22. This bypass circuit is also connected to the second four-way valve 4 in the same manner as the sub-expander 23 and the expander 6.
Here, the generator 22 includes a clutch mechanism connected to either the sub-expander 21 or the sub-expander 23. A flow path valve 25 is provided on the inflow side of the bypass circuit.
Further, the drive shaft of the expander 6 and the drive shaft of the auxiliary compressor 10 are connected, and the auxiliary compressor 10 is driven by the power recovered by the expander 6.
In this refrigerant circuit, the first four-way valve 2 to which the discharge side pipe of the compressor 1 and the suction side pipe of the auxiliary compressor 10 are connected, the discharge side pipe of the sub expander 23 and the inflow side of the expander 6 are connected. And a second four-way valve 4 to which a bypass circuit is connected.

The operation of the heat pump type air conditioning apparatus according to this embodiment will be described below.
First, the cooling operation mode using the outdoor heat exchanger 3 as a radiator and the indoor heat exchanger 8 as an evaporator will be described. The refrigerant flow in the cooling operation mode is indicated by solid line arrows in the figure.
The refrigerant in the cooling operation mode is compressed and discharged at a high temperature and a high pressure by the compressor 1 driven by the motor 12, and is introduced into the outdoor heat exchanger 3 through the first four-way valve 2. In the outdoor heat exchanger 3, since the CO ₂ refrigerant is in a supercritical state, it does not enter a gas-liquid two-phase state but radiates heat to an external fluid such as air or water. Thereafter, the CO ₂ refrigerant is introduced into the expander 6 and the sub-expander 23 and decompressed by the expander 6 and the sub-expander 23. The power recovered by the expander 6 during this decompression is used to drive the auxiliary compressor 10. At this time, for example, the optimum refrigerant amount flowing to the expander 6 is calculated from the high-pressure refrigerant temperature and the high-pressure refrigerant pressure detected on the outlet side of the outdoor heat exchanger 3, and when the volume flow rate is larger than the calculated optimum refrigerant amount, The flow rate valve 25 is opened, the generator 22 is connected to the sub-expander 21 side, and the refrigerant flows through the bypass circuit to reduce the volume flow rate flowing into the expander 6. In this case, the sub expander 23 is not operated. Further, it is preferable to change the bypass amount by adjusting the torque of the generator 22. On the other hand, when the volume flow rate is smaller than the calculated optimum refrigerant amount, the flow path valve 25 is closed, the generator 22 is connected to the sub expander 23 side, and the low pressure side pressure is lowered to flow into the expander 6. Increase volume flow. In this case, the sub expander 21 is not operated. Moreover, it is preferable to change the low pressure side pressure by adjusting the torque of the generator 22.
CO ₂ refrigerant decompressed by the sub-expander 23 and the expander 6, or the sub-expander 21 and CO ₂ refrigerant decompressed by the expander 6, an indoor heat exchanger through the second four-way valve 4 8 evaporates in the indoor heat exchanger 8 and absorbs heat. Indoor cooling is performed by this heat absorption. The evaporated refrigerant is led to the auxiliary compressor 10 through the first four-way valve 2, supercharged (charged) by the auxiliary compressor 10, and sucked into the compressor 1.

Next, a heating operation mode using the outdoor heat exchanger 3 as an evaporator and the indoor heat exchanger 8 as a radiator will be described. The refrigerant flow in the heating operation mode is indicated by a wavy arrow in the figure.
The refrigerant in the heating operation mode is compressed and discharged at a high temperature and high pressure by the compressor 1 driven by the motor 12, and is introduced into the indoor heat exchanger 8 through the first four-way valve 2. In the indoor heat exchanger 8, since the CO ₂ refrigerant is in a supercritical state, the CO ₂ refrigerant does not enter a gas-liquid two-phase state but radiates heat to an external fluid such as air or water. Heating is performed. Thereafter, the CO ₂ refrigerant is introduced into the expander 6 and the sub-expander 23 and decompressed by the expander 6 and the sub-expander 23. The power recovered by the expander 6 during this decompression is used to drive the auxiliary compressor 10. At this time, for example, the optimum refrigerant amount flowing to the expander 6 is calculated from the high-pressure refrigerant temperature and the high-pressure refrigerant pressure detected at the outlet side of the indoor heat exchanger 8, and when the volume flow rate is larger than the calculated optimum refrigerant amount, The flow rate valve 25 is opened, the generator 22 is connected to the sub-expander 21 side, and the refrigerant flows through the bypass circuit to reduce the volume flow rate flowing into the expander 6. In this case, the sub expander 23 is not operated. Further, it is preferable to change the bypass amount by adjusting the torque of the generator 22. On the other hand, when the volume flow rate is smaller than the calculated optimum refrigerant amount, the flow path valve 25 is closed, the generator 22 is connected to the sub expander 23 side, and the low pressure side pressure is lowered to flow into the expander 6. Increase volume flow. In this case, the sub expander 21 is not operated. Moreover, it is preferable to change the low pressure side pressure by adjusting the torque of the generator 22.
CO ₂ refrigerant decompressed by the sub-expander 23 and the expander 6, or the sub-expander 21 and CO ₂ refrigerant decompressed by the expander 6, an outdoor heat exchanger via the second four-way valve 4 3, the refrigerant that has evaporated and absorbed heat in the outdoor heat exchanger 3 and has been evaporated is led to the auxiliary compressor 10 via the first four-way valve 2 and is supercharged by the auxiliary compressor 10 ( And is sucked into the compressor 1.

  As described above, according to the present embodiment, the amount of refrigerant flowing through the expander 6 is adjusted by adjusting the amount of refrigerant flowing through the bypass circuit by opening the on-off valve 25 and connecting the generator 22 to the sub-expander 21. On the other hand, by adjusting the low-pressure side pressure by changing the torque of the generator 22 connected to the sub-expander 23 (ie, the load of the generator) by closing the on-off valve 25, the expander 6 can be controlled. Therefore, power can be efficiently recovered in the expander 6, and higher power recovery is performed from the refrigeration cycle by using the power recovered from the sub expander 21 or the sub expander 23 for power generation of the generator 22. be able to.

Hereinafter, a refrigeration cycle apparatus according to another embodiment of the present invention will be described with reference to the drawings for a heat pump type air conditioning apparatus.
FIG. 37 is a configuration diagram of a heat pump type air conditioning apparatus according to the present embodiment.
As shown in the figure, the heat pump type air conditioning apparatus according to the present embodiment uses a CO ₂ refrigerant as a refrigerant, a compressor 1 having a motor 12, an auxiliary compressor 10, an outdoor heat exchanger 3, and The expander 6 and the indoor heat exchanger 8 are configured by a refrigerant circuit connected by piping.
A sub-expander 23 is provided on the discharge side of the expander 6, and a generator 22 is connected to the drive shaft of the sub-expander 23.
A bypass circuit that bypasses the sub-expander 23 and the expander 6 is provided in parallel with the sub-expander 23 and the expander 6, and the sub-expander 21 is provided in the bypass circuit, and the drive shaft of the sub-expander 21 Is connected to a generator 22. This bypass circuit is also connected to the second four-way valve 4 in the same manner as the sub-expander 23 and the expander 6.
Here, the generator 22 includes a clutch mechanism connected to either the sub-expander 21 or the sub-expander 23. A flow path valve 25 is provided on the inflow side of the bypass circuit.
Further, the drive shaft of the expander 6 and the drive shaft of the auxiliary compressor 10 are connected, and the auxiliary compressor 10 is driven by the power recovered by the expander 6.
The refrigerant circuit includes a first four-way valve 2 to which a suction side pipe of the compressor 1 and a discharge side pipe of the auxiliary compressor 10 are connected, a discharge side pipe of the sub expander 23 and an inflow side of the expander 6. And a second four-way valve 4 to which a bypass circuit is connected.

The operation of the heat pump type air conditioning apparatus according to this embodiment will be described below.
First, the cooling operation mode using the outdoor heat exchanger 3 as a radiator and the indoor heat exchanger 8 as an evaporator will be described. The refrigerant flow in the cooling operation mode is indicated by solid line arrows in the figure.
The refrigerant in the cooling operation mode is compressed and discharged at a high temperature and a high pressure by the compressor 1 driven by the motor 12, guided to the auxiliary compressor 10, and further overpressure (expressor) by the auxiliary compressor 10. Then, it is introduced into the outdoor heat exchanger 3 through the first four-way valve 2. In the outdoor heat exchanger 3, since the CO ₂ refrigerant is in a supercritical state, it does not enter a gas-liquid two-phase state but radiates heat to an external fluid such as air or water. Thereafter, the CO ₂ refrigerant is introduced into the expander 6 and the sub-expander 23 and decompressed by the expander 6 and the sub-expander 23. The power recovered by the expander 6 during this decompression is used to drive the auxiliary compressor 10. At this time, for example, the optimum refrigerant amount flowing to the expander 6 is calculated from the high-pressure refrigerant temperature and the high-pressure refrigerant pressure detected on the outlet side of the outdoor heat exchanger 3, and when the volume flow rate is larger than the calculated optimum refrigerant amount, The flow rate valve 25 is opened, the generator 22 is connected to the sub-expander 21 side, and the refrigerant flows through the bypass circuit to reduce the volume flow rate flowing into the expander 6. In this case, the sub expander 23 is not operated. Further, it is preferable to change the bypass amount by adjusting the torque of the generator 22. On the other hand, when the volume flow rate is smaller than the calculated optimum refrigerant amount, the flow path valve 25 is closed, the generator 22 is connected to the sub expander 23 side, and the low pressure side pressure is lowered to flow into the expander 6. Increase volume flow. In this case, the sub expander 21 is not operated. Moreover, it is preferable to change the low pressure side pressure by adjusting the torque of the generator 22.
CO ₂ refrigerant decompressed by the sub-expander 23 and the expander 6, or the sub-expander 21 and CO ₂ refrigerant decompressed by the expander 6, an indoor heat exchanger through the second four-way valve 4 8 evaporates in the indoor heat exchanger 8 and absorbs heat. Indoor cooling is performed by this heat absorption. The evaporated refrigerant is sucked into the compressor 1 through the first four-way valve 2.

Next, a heating operation mode using the outdoor heat exchanger 3 as an evaporator and the indoor heat exchanger 8 as a radiator will be described. The refrigerant flow in the heating operation mode is indicated by a wavy arrow in the figure.
The refrigerant in the heating operation mode is compressed and discharged at a high temperature and high pressure by the compressor 1 driven by the motor 12, guided to the auxiliary compressor 10, and further overpressure (expressor) by the auxiliary compressor 10. Then, it is introduced into the indoor heat exchanger 8 through the first four-way valve 2. In the indoor heat exchanger 8, since the CO ₂ refrigerant is in a supercritical state, the CO ₂ refrigerant does not enter a gas-liquid two-phase state but radiates heat to an external fluid such as air or water. Heating is performed. Thereafter, the CO ₂ refrigerant is introduced into the expander 6 and the sub-expander 23 and decompressed by the expander 6 and the sub-expander 23. The power recovered by the expander 6 during this decompression is used to drive the auxiliary compressor 10. At this time, for example, the optimum refrigerant amount flowing to the expander 6 is calculated from the high-pressure refrigerant temperature and the high-pressure refrigerant pressure detected at the outlet side of the indoor heat exchanger 8, and when the volume flow rate is larger than the calculated optimum refrigerant amount, The flow rate valve 25 is opened, the generator 22 is connected to the sub-expander 21 side, and the refrigerant flows through the bypass circuit to reduce the volume flow rate flowing into the expander 6. In this case, the sub expander 23 is not operated. Further, it is preferable to change the bypass amount by adjusting the torque of the generator 22. On the other hand, when the volume flow rate is smaller than the calculated optimum refrigerant amount, the flow path valve 25 is closed, the generator 22 is connected to the sub expander 23 side, and the low pressure side pressure is lowered to flow into the expander 6. Increase volume flow. In this case, the sub expander 21 is not operated. Moreover, it is preferable to change the low pressure side pressure by adjusting the torque of the generator 22.
CO ₂ refrigerant decompressed by the sub-expander 23 and the expander 6, or the sub-expander 21 and CO ₂ refrigerant decompressed by the expander 6, an outdoor heat exchanger via the second four-way valve 4 3, the refrigerant evaporating and absorbing heat in the outdoor heat exchanger 3, and the evaporated refrigerant is sucked into the compressor 1 through the first four-way valve 2.

  As described above, according to the present embodiment, the amount of refrigerant flowing through the expander 6 is adjusted by adjusting the amount of refrigerant flowing through the bypass circuit by opening the on-off valve 25 and connecting the generator 22 to the sub-expander 21. On the other hand, by adjusting the low pressure side pressure by changing the torque of the generator 24 connected to the sub-expander 23 (ie, the load of the generator) by closing the on-off valve 25, the expander 6 can be controlled. Therefore, power can be efficiently recovered in the expander 6, and higher power recovery is performed from the refrigeration cycle by using the power recovered from the sub expander 21 or the sub expander 23 for power generation of the generator 22. be able to.

Hereinafter, a refrigeration cycle apparatus according to another embodiment of the present invention will be described with reference to the drawings for a heat pump type air conditioning apparatus.
FIG. 38 is a configuration diagram of a heat pump air-conditioning type air conditioner according to the present embodiment.
As shown in the figure, the heat pump air-conditioning type air conditioner according to the present embodiment uses a CO ₂ refrigerant as a refrigerant, a compressor 1 having a motor 12, an outdoor heat exchanger 3, an expander 6, It is comprised from the refrigerant circuit which connected the indoor side heat exchanger 8 and the auxiliary compressor 10 with piping.
The refrigerant circuit includes a first four-way valve 2 to which a discharge side pipe and a suction side pipe of the compressor 1 are connected, and a second four-way valve to which a discharge side pipe and a suction side pipe of the expander 6 are connected. 4 and a third four-way valve 9 to which the discharge side pipe and the suction side pipe of the auxiliary compressor 10 are connected. In the case of a refrigerant flow in which the outdoor heat exchanger 3 is a radiator and the indoor heat exchanger 8 is an evaporator, the discharge of the auxiliary compressor 10 is performed by switching between the first four-way valve 2 and the third four-way valve 9. The side is configured to be the suction side of the compressor 1. In the case of a refrigerant flow in which the outdoor heat exchanger 3 is an evaporator and the indoor heat exchanger 8 is a radiator, the compressor 1 is switched by switching between the first four-way valve 2 and the third four-way valve 9. The discharge side is configured to be the suction side of the auxiliary compressor 10. Further, the direction of the refrigerant flowing through the expander 6 is always set to the same direction by switching the second four-way valve 4.
A bypass circuit that bypasses the expander 6 is provided in parallel with the expander 6, a sub-expander 21 is provided in the bypass circuit, and a generator 22 is connected to the drive shaft of the sub-expander 21. . This bypass circuit is also connected to the second four-way valve 4 in the same manner as the expander 6.
Further, the drive shaft of the expander 6 and the drive shaft of the auxiliary compressor 10 are connected, and the auxiliary compressor 10 is driven by the power recovered by the expander 6.

The operation of the heat pump type air conditioning apparatus according to this embodiment will be described below.
First, the cooling operation mode using the outdoor heat exchanger 3 as a radiator and the indoor heat exchanger 8 as an evaporator will be described. The refrigerant flow in the cooling operation mode is indicated by solid line arrows in the figure.
The refrigerant in the cooling operation mode is compressed and discharged at a high temperature and a high pressure by the compressor 1 driven by the motor 12, and is introduced into the outdoor heat exchanger 3 through the first four-way valve 2. In the outdoor heat exchanger 3, since the CO ₂ refrigerant is in a supercritical state, it does not enter a gas-liquid two-phase state but radiates heat to an external fluid such as air or water. Thereafter, the CO ₂ refrigerant is introduced into the expander 6 and the sub expander 21 through the second four-way valve 4, and decompressed by the expander 6 or the sub expander 21. The power recovered by the expander 6 during this decompression is used to drive the auxiliary compressor 10. At this time, for example, the optimum refrigerant amount flowing to the expander 6 is calculated from the high-pressure refrigerant temperature and the high-pressure refrigerant pressure detected at the outlet side of the outdoor heat exchanger 3, and when the volume flow rate is larger than the calculated optimum refrigerant amount The volume flow rate flowing into the expander 6 is decreased by decreasing the torque (generator load) of the machine 22 and increasing the amount of refrigerant flowing through the bypass circuit. Further, when the optimum refrigerant amount flowing through the expander 6 is smaller than the calculated optimum refrigerant amount, the torque (generator load) of the generator 22 is increased to reduce the refrigerant amount flowing into the bypass circuit, thereby flowing into the expander 6. Increase the volume flow rate.
The CO ₂ refrigerant decompressed by the sub-expander 21 and the expander 6 is guided to the indoor heat exchanger 8 via the second four-way valve 4 and is evaporated and absorbs heat in the indoor heat exchanger 8. Indoor cooling is performed by this heat absorption. The evaporated refrigerant is guided to the auxiliary compressor 10 through the second four-way valve 9, supercharged (charged) by the auxiliary compressor 10, and sucked into the compressor 1.

Next, a heating operation mode using the outdoor heat exchanger 3 as an evaporator and the indoor heat exchanger 8 as a radiator will be described. The refrigerant flow in the heating operation mode is indicated by a wavy arrow in the figure.
The refrigerant in the heating operation mode is compressed and discharged at a high temperature and high pressure by the compressor 1 driven by the motor 12, and is guided to the auxiliary compressor 10 through the first four-way valve 2 and the third four-way valve 9 to assist. The compressor 10 further overpressures (expressor). The refrigerant overpressured by the auxiliary compressor 10 is introduced into the indoor heat exchanger 8 through the third four-way valve 9. In the indoor heat exchanger 8, since the CO ₂ refrigerant is in a supercritical state, the CO ₂ refrigerant does not enter a gas-liquid two-phase state but radiates heat to an external fluid such as air or water. Heating is performed. Thereafter, the CO ₂ refrigerant is introduced into the expander 6 and the sub expander 21 through the second four-way valve 4, and decompressed by the expander 6 or the sub expander 21. The power recovered by the expander 6 during this decompression is used to drive the auxiliary compressor 10. At this time, for example, the optimum refrigerant amount flowing to the expander 6 is calculated from the high-pressure refrigerant temperature and the high-pressure refrigerant pressure detected on the outlet side of the indoor heat exchanger 8, and power generation is performed when the volume flow rate is larger than the calculated optimum refrigerant amount. The volume flow rate flowing into the expander 6 is decreased by decreasing the torque (generator load) of the machine 22 and increasing the amount of refrigerant flowing through the bypass circuit. Further, when the optimum refrigerant amount flowing through the expander 6 is smaller than the calculated optimum refrigerant amount, the torque (generator load) of the generator 22 is increased to reduce the refrigerant amount flowing into the bypass circuit, thereby flowing into the expander 6. Increase the volume flow rate.
The CO ₂ refrigerant depressurized by the expander 6 and the sub-expander 21 is guided to the outdoor heat exchanger 3 via the second four-way valve 4 and is evaporated and absorbs heat in the outdoor heat exchanger 3. The evaporated refrigerant is sucked into the compressor 1 via the first four-way valve 2.

As described above, according to the present embodiment, the expander is configured by adjusting the amount of refrigerant flowing through the bypass circuit by changing the torque of the generator 22 connected to the sub expander 21 (that is, the load of the generator). 6 can be controlled. Accordingly, power can be efficiently recovered in the expander 6, and higher power recovery can be achieved from the refrigeration cycle by using the power recovered from the sub expander 21 for power generation of the generator 22 during this bypass flow rate control. It can be performed.
Further, according to the present embodiment, the compressor 1 that compresses the refrigerant, the expander 6 that recovers power, and the auxiliary compressor 10 are installed separately, and supercharged (charger) by the auxiliary compressor 10 in the cooling operation mode. The expansion unit 6 can be operated as a charger-type expansion unit suitable for cooling, and can be operated as an expansion unit suitable for heating. It can also be operated as a presser type expander.

Hereinafter, a refrigeration cycle apparatus according to another embodiment of the present invention will be described with reference to the drawings for a heat pump type air conditioning apparatus.
FIG. 39 is a configuration diagram of the heat pump air-conditioning type air conditioner according to the present embodiment.
As shown in the figure, the heat pump air-conditioning type air conditioner according to the present embodiment uses a CO ₂ refrigerant as a refrigerant, a compressor 1 having a motor 12, an outdoor heat exchanger 3, an expander 6, It is comprised from the refrigerant circuit which connected the indoor side heat exchanger 8 and the auxiliary compressor 10 with piping.
A sub expander 23 is provided on the inflow side of the expander 6, and a generator 24 is connected to a drive shaft of the sub expander 23.
Further, the drive shaft of the expander 6 and the drive shaft of the auxiliary compressor 10 are connected, and the auxiliary compressor 10 is driven by the power recovered by the expander 6.
The refrigerant circuit includes a first four-way valve 2 to which a discharge side pipe and a suction side pipe of the compressor 1 are connected, and a second four-way valve to which a discharge side pipe and a suction side pipe of the expander 6 are connected. 4 and a third four-way valve 9 to which the discharge side pipe and the suction side pipe of the auxiliary compressor 10 are connected. In the case of a refrigerant flow in which the outdoor heat exchanger 3 is a radiator and the indoor heat exchanger 8 is an evaporator, the discharge of the auxiliary compressor 10 is performed by switching between the first four-way valve 2 and the third four-way valve 9. The side is configured to be the suction side of the compressor 1. In the case of a refrigerant flow in which the outdoor heat exchanger 3 is an evaporator and the indoor heat exchanger 8 is a radiator, the compressor 1 is switched by switching between the first four-way valve 2 and the third four-way valve 9. The discharge side is configured to be the suction side of the auxiliary compressor 10. Further, the direction of the refrigerant flowing through the expander 6 is always set to the same direction by switching the second four-way valve 4.

The operation of the heat pump type air conditioning apparatus according to this embodiment will be described below.
First, the cooling operation mode using the outdoor heat exchanger 3 as a radiator and the indoor heat exchanger 8 as an evaporator will be described. The refrigerant flow in the cooling operation mode is indicated by solid line arrows in the figure.
The refrigerant in the cooling operation mode is compressed and discharged at a high temperature and a high pressure by the compressor 1 driven by the motor 12, and is introduced into the outdoor heat exchanger 3 through the first four-way valve 2. In the outdoor heat exchanger 3, since the CO ₂ refrigerant is in a supercritical state, it does not enter a gas-liquid two-phase state but radiates heat to an external fluid such as air or water. Thereafter, the CO ₂ refrigerant is introduced into the sub expander 23 and the expander 6 through the second four-way valve 4, and is depressurized by the sub expander 23 and the expander 6. The power recovered by the expander 6 during this decompression is used to drive the auxiliary compressor 10. At this time, for example, the optimum refrigerant amount flowing to the expander 6 is calculated from the high-pressure refrigerant temperature and the high-pressure refrigerant pressure detected on the outlet side of the outdoor heat exchanger 3, and power generation is performed when the volume flow rate is smaller than the calculated optimum refrigerant amount. The volume flow rate flowing into the expander 6 is increased by increasing the torque (generator load) of the machine 24 and increasing the high-pressure side pressure. Further, when the optimum refrigerant amount flowing into the expander 6 is larger than the calculated optimum refrigerant amount, the volume flow rate flowing into the expander 6 by decreasing the torque (generator load) of the generator 24 and reducing the high-pressure side pressure. Decrease.
The CO ₂ refrigerant decompressed by the sub-expander 23 and the expander 6 is guided to the indoor heat exchanger 8 via the second four-way valve 4, and is evaporated and absorbs heat in the indoor heat exchanger 8. Indoor cooling is performed by this heat absorption. The evaporated refrigerant is guided to the auxiliary compressor 10 through the second four-way valve 9, supercharged (charged) by the auxiliary compressor 10, and sucked into the compressor 1.

Next, a heating operation mode using the outdoor heat exchanger 3 as an evaporator and the indoor heat exchanger 8 as a radiator will be described. The refrigerant flow in the heating operation mode is indicated by a wavy arrow in the figure.
The refrigerant in the heating operation mode is compressed and discharged at a high temperature and high pressure by the compressor 1 driven by the motor 12, and is guided to the auxiliary compressor 10 through the first four-way valve 2 and the third four-way valve 9 to assist. The compressor 10 further overpressures (expressor). The refrigerant overpressured by the auxiliary compressor 10 is introduced into the indoor heat exchanger 8 through the third four-way valve 9. In the indoor heat exchanger 8, since the CO ₂ refrigerant is in a supercritical state, the CO ₂ refrigerant does not enter a gas-liquid two-phase state but radiates heat to an external fluid such as air or water. Heating is performed. Thereafter, the CO ₂ refrigerant is introduced into the sub expander 23 and the expander 6 through the second four-way valve 4, and is depressurized by the sub expander 23 and the expander 6. The power recovered by the expander 6 during this decompression is used to drive the auxiliary compressor 10. At this time, for example, the optimum refrigerant amount flowing to the expander 6 is calculated from the high-pressure refrigerant temperature and the high-pressure refrigerant pressure detected at the outlet side of the indoor heat exchanger 8, and power generation is performed when the volume flow rate is smaller than the calculated optimum refrigerant amount. The volume flow rate flowing into the expander 6 is increased by increasing the torque (generator load) of the machine 24 and increasing the high-pressure side pressure. Further, when the optimum refrigerant amount flowing into the expander 6 is larger than the calculated optimum refrigerant amount, the volume flow rate flowing into the expander 6 by decreasing the torque (generator load) of the generator 24 and reducing the high-pressure side pressure. Decrease.
The CO ₂ refrigerant depressurized by the sub-expander 23 and the expander 6 evaporates and absorbs heat in the outdoor heat exchanger 3, and the evaporated refrigerant passes through the first four-way valve 2 and is compressed by the compressor 1. Inhaled.

As described above, according to this embodiment, the torque of the generator 24 connected to the sub-expander 23 (that is, the load of the generator) is changed to adjust the high-pressure side pressure to flow into the expander 6. The amount of refrigerant can be controlled. Therefore, power can be recovered efficiently in the expander 6, and higher power can be recovered from the refrigeration cycle by using the power recovered from the sub-expander 23 for power generation by the generator 24.
Further, according to the present embodiment, the compressor 1 that compresses the refrigerant, the expander 6 that recovers power, and the auxiliary compressor 10 are installed separately, and supercharged (charger) by the auxiliary compressor 10 in the cooling operation mode. The expansion unit 6 can be operated as a charger-type expansion unit suitable for cooling, and can be operated as an expansion unit suitable for heating. It can also be operated as a presser type expander.

Hereinafter, a refrigeration cycle apparatus according to another embodiment of the present invention will be described with reference to the drawings for a heat pump type air conditioning apparatus.
FIG. 40 is a configuration diagram of a heat pump air-conditioning type air conditioner according to the present embodiment.
As shown in the figure, the heat pump air-conditioning type air conditioner according to the present embodiment uses a CO ₂ refrigerant as a refrigerant, a compressor 1 having a motor 12, an outdoor heat exchanger 3, an expander 6, It is comprised from the refrigerant circuit which connected the indoor side heat exchanger 8 and the auxiliary compressor 10 with piping.
A sub expander 23 is provided on the discharge side of the expander 6, and a generator 24 is connected to the drive shaft of the sub expander 23.
Further, the drive shaft of the expander 6 and the drive shaft of the auxiliary compressor 10 are connected, and the auxiliary compressor 10 is driven by the power recovered by the expander 6.
The refrigerant circuit includes a first four-way valve 2 to which a discharge side pipe and a suction side pipe of the compressor 1 are connected, and a second four-way valve to which a discharge side pipe and a suction side pipe of the expander 6 are connected. 4 and a third four-way valve 9 to which the discharge side pipe and the suction side pipe of the auxiliary compressor 10 are connected. In the case of a refrigerant flow in which the outdoor heat exchanger 3 is a radiator and the indoor heat exchanger 8 is an evaporator, the discharge of the auxiliary compressor 10 is performed by switching between the first four-way valve 2 and the third four-way valve 9. The side is configured to be the suction side of the compressor 1. In the case of a refrigerant flow in which the outdoor heat exchanger 3 is an evaporator and the indoor heat exchanger 8 is a radiator, the compressor 1 is switched by switching between the first four-way valve 2 and the third four-way valve 9. The discharge side is configured to be the suction side of the auxiliary compressor 10. Further, the direction of the refrigerant flowing through the expander 6 is always set to the same direction by switching the second four-way valve 4.

The operation of the heat pump type air conditioning apparatus according to this embodiment will be described below.
First, the cooling operation mode using the outdoor heat exchanger 3 as a radiator and the indoor heat exchanger 8 as an evaporator will be described. The refrigerant flow in the cooling operation mode is indicated by solid line arrows in the figure.
The refrigerant in the cooling operation mode is compressed and discharged at a high temperature and a high pressure by the compressor 1 driven by the motor 12, and is introduced into the outdoor heat exchanger 3 through the first four-way valve 2. In the outdoor heat exchanger 3, since the CO ₂ refrigerant is in a supercritical state, it does not enter a gas-liquid two-phase state but radiates heat to an external fluid such as air or water. Thereafter, the CO ₂ refrigerant is introduced into the expander 6 and the sub expander 23 through the second four-way valve 4, and is decompressed by the expander 6 and the sub expander 23. The power recovered by the expander 6 during this decompression is used to drive the auxiliary compressor 10. At this time, for example, the optimum refrigerant amount flowing to the expander 6 is calculated from the high-pressure refrigerant temperature and the high-pressure refrigerant pressure detected on the outlet side of the outdoor heat exchanger 3, and power generation is performed when the volume flow rate is smaller than the calculated optimum refrigerant amount. The volume flow rate flowing into the expander 6 is increased by increasing the torque (generator load) of the machine 22 and lowering the low pressure side pressure. Further, when the optimum refrigerant amount flowing through the expander 6 is larger than the calculated optimum refrigerant amount, the volume flow rate flowing into the expander 6 by decreasing the torque (generator load) of the generator 22 and increasing the low-pressure side pressure. Decrease.
The CO ₂ refrigerant decompressed by the expander 6 and the sub-expander 23 is guided to the indoor heat exchanger 8 via the second four-way valve 4 and is evaporated and absorbs heat by the indoor heat exchanger 8. . Indoor cooling is performed by this heat absorption. The evaporated refrigerant is guided to the auxiliary compressor 10 through the second four-way valve 9, supercharged (charged) by the auxiliary compressor 10, and sucked into the compressor 1.

Next, a heating operation mode using the outdoor heat exchanger 3 as an evaporator and the indoor heat exchanger 8 as a radiator will be described. The refrigerant flow in the heating operation mode is indicated by a wavy arrow in the figure.
The refrigerant in the heating operation mode is compressed and discharged at a high temperature and high pressure by the compressor 1 driven by the motor 12, and is guided to the auxiliary compressor 10 through the first four-way valve 2 and the third four-way valve 9 to assist. The compressor 10 further overpressures (expressor). The refrigerant overpressured by the auxiliary compressor 10 is introduced into the indoor heat exchanger 8 through the third four-way valve 9. In the indoor heat exchanger 8, since the CO ₂ refrigerant is in a supercritical state, the CO ₂ refrigerant does not enter a gas-liquid two-phase state but radiates heat to an external fluid such as air or water. Heating is performed. Thereafter, the CO ₂ refrigerant is introduced into the expander 6 and the sub expander 23 through the second four-way valve 4, and is decompressed by the expander 6 and the sub expander 23. The power recovered by the expander 6 during this decompression is used to drive the auxiliary compressor 10. At this time, for example, the optimum refrigerant amount flowing to the expander 6 is calculated from the high-pressure refrigerant temperature and the high-pressure refrigerant pressure detected at the outlet side of the indoor heat exchanger 8, and power generation is performed when the volume flow rate is smaller than the calculated optimum refrigerant amount. The volume flow rate flowing into the expander 6 is increased by increasing the torque (generator load) of the machine 22 and lowering the low pressure side pressure. Further, when the optimum refrigerant amount flowing through the expander 6 is larger than the calculated optimum refrigerant amount, the volume flow rate flowing into the expander 6 by decreasing the torque (generator load) of the generator 22 and increasing the low-pressure side pressure. Decrease.
The CO ₂ refrigerant depressurized by the expander 6 and the sub-expander 23 evaporates and absorbs heat in the outdoor heat exchanger 3, and the refrigerant that has finished evaporating passes through the first four-way valve 2 to compress the compressor 1. Inhaled.

As described above, according to the present embodiment, the low-pressure side pressure is adjusted by changing the torque of the generator 22 connected to the sub-expander 23 (that is, the load of the generator) to flow into the expander 6. The amount of refrigerant can be controlled. Therefore, power can be recovered efficiently in the expander 6, and higher power can be recovered from the refrigeration cycle by using the power recovered from the sub-expander 23 for power generation by the generator 24.
Further, according to the present embodiment, the compressor 1 that compresses the refrigerant, the expander 6 that recovers power, and the auxiliary compressor 10 are installed separately, and supercharged (charger) by the auxiliary compressor 10 in the cooling operation mode. The expansion unit 6 can be operated as a charger-type expansion unit suitable for cooling, and can be operated as an expansion unit suitable for heating. It can also be operated as a presser type expander.

Hereinafter, a refrigeration cycle apparatus according to another embodiment of the present invention will be described with reference to the drawings for a heat pump type air conditioning apparatus.
FIG. 41 is a configuration diagram of a heat pump air-conditioning type air conditioner according to the present embodiment.
As shown in the figure, the heat pump air-conditioning type air conditioner according to the present embodiment uses a CO ₂ refrigerant as a refrigerant, a compressor 1 having a motor 12, an outdoor heat exchanger 3, an expander 6, It is comprised from the refrigerant circuit which connected the indoor side heat exchanger 8 and the auxiliary compressor 10 with piping.
A sub expander 23 is provided on the inflow side of the expander 6, and a generator 24 is connected to a drive shaft of the sub expander 23.
A bypass circuit that bypasses the sub-expander 23 and the expander 6 is provided in parallel with the sub-expander 23 and the expander 6, and the sub-expander 21 is provided in the bypass circuit, and the drive shaft of the sub-expander 21 Is connected to a generator 22. This bypass circuit is also connected to the second four-way valve 4 in the same manner as the sub-expander 23 and the expander 6.
Further, the drive shaft of the expander 6 and the drive shaft of the auxiliary compressor 10 are connected, and the auxiliary compressor 10 is driven by the power recovered by the expander 6.
The refrigerant circuit includes a first four-way valve 2 to which a discharge side pipe and a suction side pipe of the compressor 1 are connected, and a second four-way valve to which a discharge side pipe and a suction side pipe of the expander 6 are connected. 4 and a third four-way valve 9 to which the discharge side pipe and the suction side pipe of the auxiliary compressor 10 are connected. In the case of a refrigerant flow in which the outdoor heat exchanger 3 is a radiator and the indoor heat exchanger 8 is an evaporator, the discharge of the auxiliary compressor 10 is performed by switching between the first four-way valve 2 and the third four-way valve 9. The side is configured to be the suction side of the compressor 1. In the case of a refrigerant flow in which the outdoor heat exchanger 3 is an evaporator and the indoor heat exchanger 8 is a radiator, the compressor 1 is switched by switching between the first four-way valve 2 and the third four-way valve 9. The discharge side is configured to be the suction side of the auxiliary compressor 10. Further, the direction of the refrigerant flowing through the expander 6 is always set to the same direction by switching the second four-way valve 4.

The operation of the heat pump type air conditioning apparatus according to this embodiment will be described below.
First, the cooling operation mode using the outdoor heat exchanger 3 as a radiator and the indoor heat exchanger 8 as an evaporator will be described. The refrigerant flow in the cooling operation mode is indicated by solid line arrows in the figure.
The refrigerant in the cooling operation mode is compressed and discharged at a high temperature and a high pressure by the compressor 1 driven by the motor 12, and is introduced into the outdoor heat exchanger 3 through the first four-way valve 2. In the outdoor heat exchanger 3, since the CO ₂ refrigerant is in a supercritical state, it does not enter a gas-liquid two-phase state but radiates heat to an external fluid such as air or water. Thereafter, the CO ₂ refrigerant is introduced into the sub expander 23, the expander 6, and the sub expander 21, and decompressed by the sub expander 23, the expander 6, and the sub expander 21. The power recovered by the expander 6 during this decompression is used to drive the auxiliary compressor 10. At this time, for example, the optimum refrigerant amount flowing to the expander 6 is calculated from the high-pressure refrigerant temperature and the high-pressure refrigerant pressure detected at the outlet side of the outdoor heat exchanger 3, and when the volume flow rate is larger than the calculated optimum refrigerant amount The volume flow rate flowing into the expander 6 is decreased by decreasing the torque (generator load) of the machine 22 and increasing the amount of refrigerant flowing through the bypass circuit. On the other hand, when the volume flow rate is smaller than the calculated optimum refrigerant amount, the volume flow rate flowing into the expander 6 is increased by increasing the torque (generator load) of the generator 24 and increasing the high-pressure side pressure.
CO ₂ refrigerant decompressed by the sub-expander 23 and the expander 6 CO reduced in pressure by _second refrigerant or sub expander 21 is guided to the indoor heat exchanger 8 through the second four-way valve 4, It evaporates and absorbs heat in the indoor heat exchanger 8. Indoor cooling is performed by this heat absorption. The evaporated refrigerant is guided to the auxiliary compressor 10 through the second four-way valve 9, supercharged (charged) by the auxiliary compressor 10, and sucked into the compressor 1.

Next, a heating operation mode using the outdoor heat exchanger 3 as an evaporator and the indoor heat exchanger 8 as a radiator will be described. The refrigerant flow in the heating operation mode is indicated by a wavy arrow in the figure.
The refrigerant in the heating operation mode is compressed and discharged at a high temperature and high pressure by the compressor 1 driven by the motor 12, and is guided to the auxiliary compressor 10 through the first four-way valve 2 and the third four-way valve 9 to assist. The compressor 10 further overpressures (expressor). The refrigerant overpressured by the auxiliary compressor 10 is introduced into the indoor heat exchanger 8 through the third four-way valve 9. In the indoor heat exchanger 8, since the CO ₂ refrigerant is in a supercritical state, the CO ₂ refrigerant does not enter a gas-liquid two-phase state but radiates heat to an external fluid such as air or water. Heating is performed. Thereafter, the CO ₂ refrigerant is introduced into the sub expander 23, the expander 6, and the sub expander 21, and decompressed by the sub expander 23, the expander 6, and the sub expander 21. The power recovered by the expander 6 during this decompression is used to drive the auxiliary compressor 10. At this time, for example, the optimum refrigerant amount flowing to the expander 6 is calculated from the high-pressure refrigerant temperature and the high-pressure refrigerant pressure detected on the outlet side of the indoor heat exchanger 8, and power generation is performed when the volume flow rate is larger than the calculated optimum refrigerant amount. The volume flow rate flowing into the expander 6 is decreased by decreasing the torque (generator load) of the machine 22 and increasing the amount of refrigerant flowing through the bypass circuit. On the other hand, when the volume flow rate is smaller than the calculated optimum refrigerant amount, the volume flow rate flowing into the expander 6 is increased by increasing the torque (generator load) of the generator 24 and increasing the high-pressure side pressure.
CO ₂ refrigerant decompressed by the sub-expander 23 and the expander 6 CO reduced in pressure by _second refrigerant or sub expander 21 is guided to the outdoor heat exchanger 3 through the second four-way valve 4, The refrigerant that has evaporated and absorbed heat in the outdoor heat exchanger 3 and has finished evaporation is sucked into the compressor 1 via the first four-way valve 2.

As described above, according to the present embodiment, the expander is configured by adjusting the amount of refrigerant flowing through the bypass circuit by changing the torque of the generator 22 connected to the sub expander 21 (that is, the load of the generator). The amount of refrigerant flowing through the sub-expander 23 can be controlled, while the high-pressure side pressure is adjusted by changing the torque of the generator 24 connected to the sub-expander 23 (ie, the load of the generator). It is possible to control the amount of refrigerant flowing in the tank. Therefore, power can be efficiently recovered in the expander 6, and the power recovered from the sub-expander 21 and the sub-expander 23 is used for power generation by the generator 22 and the generator 24. Power recovery can be performed.
Further, according to the present embodiment, the compressor 1 that compresses the refrigerant, the expander 6 that recovers power, and the auxiliary compressor 10 are installed separately, and supercharged (charger) by the auxiliary compressor 10 in the cooling operation mode. The expansion unit 6 can be operated as a charger-type expansion unit suitable for cooling, and can be operated as an expansion unit suitable for heating. It can also be operated as a presser type expander.

Hereinafter, a refrigeration cycle apparatus according to another embodiment of the present invention will be described with reference to the drawings for a heat pump type air conditioning apparatus.
FIG. 42 is a configuration diagram of a heat pump air-conditioning type air conditioner according to the present embodiment.
As shown in the figure, the heat pump air-conditioning type air conditioner according to the present embodiment uses a CO ₂ refrigerant as a refrigerant, a compressor 1 having a motor 12, an outdoor heat exchanger 3, an expander 6, It is comprised from the refrigerant circuit which connected the indoor side heat exchanger 8 and the auxiliary compressor 10 with piping.
A sub expander 23 is provided on the inflow side of the expander 6, and a generator 24 is connected to a drive shaft of the sub expander 23.
A bypass circuit that bypasses the sub-expander 23 and the expander 6 is provided in parallel with the sub-expander 23 and the expander 6, and a bypass valve 7 is provided in the bypass circuit. This bypass circuit is also connected to the second four-way valve 4 in the same manner as the sub-expander 23 and the expander 6.
Further, the drive shaft of the expander 6 and the drive shaft of the auxiliary compressor 10 are connected, and the auxiliary compressor 10 is driven by the power recovered by the expander 6.
The refrigerant circuit includes a first four-way valve 2 to which a discharge side pipe and a suction side pipe of the compressor 1 are connected, and a second four-way valve to which a discharge side pipe and a suction side pipe of the expander 6 are connected. 4 and a third four-way valve 9 to which the discharge side pipe and the suction side pipe of the auxiliary compressor 10 are connected. In the case of a refrigerant flow in which the outdoor heat exchanger 3 is a radiator and the indoor heat exchanger 8 is an evaporator, the discharge of the auxiliary compressor 10 is performed by switching between the first four-way valve 2 and the third four-way valve 9. The side is configured to be the suction side of the compressor 1. In the case of a refrigerant flow in which the outdoor heat exchanger 3 is an evaporator and the indoor heat exchanger 8 is a radiator, the compressor 1 is switched by switching between the first four-way valve 2 and the third four-way valve 9. The discharge side is configured to be the suction side of the auxiliary compressor 10. Further, the direction of the refrigerant flowing through the expander 6 is always set to the same direction by switching the second four-way valve 4.

The operation of the heat pump type air conditioning apparatus according to this embodiment will be described below.
First, the cooling operation mode using the outdoor heat exchanger 3 as a radiator and the indoor heat exchanger 8 as an evaporator will be described. The refrigerant flow in the cooling operation mode is indicated by solid line arrows in the figure.
The refrigerant in the cooling operation mode is compressed and discharged at a high temperature and a high pressure by the compressor 1 driven by the motor 12, and is introduced into the outdoor heat exchanger 3 through the first four-way valve 2. In the outdoor heat exchanger 3, since the CO ₂ refrigerant is in a supercritical state, it does not enter a gas-liquid two-phase state but radiates heat to an external fluid such as air or water. Thereafter, the CO ₂ refrigerant is introduced into the sub-expander 23 and the expander 6 and decompressed by the sub-expander 23 and the expander 6. The power recovered by the expander 6 during this decompression is used to drive the auxiliary compressor 10. At this time, for example, the optimum refrigerant amount flowing to the expander 6 is calculated from the high-pressure refrigerant temperature and the high-pressure refrigerant pressure detected at the outlet side of the outdoor heat exchanger 3, and when the volume flow rate is larger than the calculated optimum refrigerant amount, bypass is performed. By increasing the opening of the valve 7 and increasing the amount of refrigerant flowing through the bypass circuit, the volume flow rate flowing into the expander 6 is decreased. On the other hand, when the volume flow rate is smaller than the calculated optimum refrigerant amount, the volume flow rate flowing into the expander 6 is increased by increasing the torque (generator load) of the generator 24 and increasing the high-pressure side pressure.
The CO ₂ refrigerant decompressed by the sub-expander 23 and the expander 6 is guided to the indoor heat exchanger 8 via the second four-way valve 4 and is evaporated and absorbs heat in the indoor heat exchanger 8. . Indoor cooling is performed by this heat absorption. The evaporated refrigerant is guided to the auxiliary compressor 10 through the second four-way valve 9, supercharged (charged) by the auxiliary compressor 10, and sucked into the compressor 1.

Next, a heating operation mode using the outdoor heat exchanger 3 as an evaporator and the indoor heat exchanger 8 as a radiator will be described. The refrigerant flow in the heating operation mode is indicated by a wavy arrow in the figure.
The refrigerant in the heating operation mode is compressed and discharged at a high temperature and high pressure by the compressor 1 driven by the motor 12, and is guided to the auxiliary compressor 10 through the first four-way valve 2 and the third four-way valve 9 to assist. The compressor 10 further overpressures (expressor). The refrigerant overpressured by the auxiliary compressor 10 is introduced into the indoor heat exchanger 8 through the third four-way valve 9. In the indoor heat exchanger 8, since the CO ₂ refrigerant is in a supercritical state, the CO ₂ refrigerant does not enter a gas-liquid two-phase state but radiates heat to an external fluid such as air or water. Heating is performed. Thereafter, the CO ₂ refrigerant is introduced into the sub-expander 23 and the expander 6 and decompressed by the sub-expander 23 and the expander 6. The power recovered by the expander 6 during this decompression is used to drive the auxiliary compressor 10. At this time, for example, the optimum refrigerant amount flowing to the expander 6 is calculated from the high-pressure refrigerant temperature and the high-pressure refrigerant pressure detected at the outlet side of the indoor heat exchanger 8, and when the volume flow rate is larger than the calculated optimum refrigerant amount, bypass is performed. By increasing the opening of the valve 7 and increasing the amount of refrigerant flowing through the bypass circuit, the volume flow rate flowing into the expander 6 is decreased. On the other hand, when the volume flow rate is smaller than the calculated optimum refrigerant amount, the volume flow rate flowing into the expander 6 is increased by increasing the torque (generator load) of the generator 24 and increasing the high-pressure side pressure.
The CO ₂ refrigerant decompressed by the sub-expander 23 and the expander 6 is guided to the outdoor heat exchanger 3 via the second four-way valve 4 and is evaporated and absorbs heat in the outdoor heat exchanger 3. The evaporated refrigerant is sucked into the compressor 1 via the first four-way valve 2.

As described above, according to this embodiment, the amount of refrigerant flowing through the expander 6 can be controlled by adjusting the amount of refrigerant flowing through the bypass circuit by changing the opening of the bypass valve 7. The amount of refrigerant flowing through the expander 6 can be controlled by changing the torque of the generator 24 connected to the sub-expander 23 (that is, the load of the generator) to adjust the high-pressure side pressure. Therefore, power can be recovered efficiently in the expander 6, and higher power can be recovered from the refrigeration cycle by using the power recovered from the sub-expander 23 for power generation by the generator 24.
Further, according to the present embodiment, the compressor 1 that compresses the refrigerant, the expander 6 that recovers power, and the auxiliary compressor 10 are installed separately, and supercharged (charger) by the auxiliary compressor 10 in the cooling operation mode. The expansion unit 6 can be operated as a charger-type expansion unit suitable for cooling, and can be operated as an expansion unit suitable for heating. It can also be operated as a presser type expander.

Hereinafter, a refrigeration cycle apparatus according to another embodiment of the present invention will be described with reference to the drawings for a heat pump type air conditioning apparatus.
FIG. 43 is a configuration diagram of a heat pump air-conditioning type air conditioner according to the present embodiment.
As shown in the figure, the heat pump air-conditioning type air conditioner according to the present embodiment uses a CO ₂ refrigerant as a refrigerant, a compressor 1 having a motor 12, an outdoor heat exchanger 3, an expander 6, It is comprised from the refrigerant circuit which connected the indoor side heat exchanger 8 and the auxiliary compressor 10 with piping.
A pre-expansion valve 5 is provided on the inflow side of the expander 6.
A bypass circuit for bypassing the pre-expansion valve 5 and the expander 6 is provided in parallel with the pre-expansion valve 5 and the expander 6, and a sub-expander is provided in the bypass circuit. Is connected to a generator 22. This bypass circuit is also connected to the second four-way valve 4 in the same manner as the sub-expander 23 and the expander 6.
Further, the drive shaft of the expander 6 and the drive shaft of the auxiliary compressor 10 are connected, and the auxiliary compressor 10 is driven by the power recovered by the expander 6.
The refrigerant circuit includes a first four-way valve 2 to which a discharge side pipe and a suction side pipe of the compressor 1 are connected, and a second four-way valve to which a discharge side pipe and a suction side pipe of the expander 6 are connected. 4 and a third four-way valve 9 to which the discharge side pipe and the suction side pipe of the auxiliary compressor 10 are connected. In the case of a refrigerant flow in which the outdoor heat exchanger 3 is a radiator and the indoor heat exchanger 8 is an evaporator, the discharge of the auxiliary compressor 10 is performed by switching between the first four-way valve 2 and the third four-way valve 9. The side is configured to be the suction side of the compressor 1. In the case of a refrigerant flow in which the outdoor heat exchanger 3 is an evaporator and the indoor heat exchanger 8 is a radiator, the compressor 1 is switched by switching between the first four-way valve 2 and the third four-way valve 9. The discharge side is configured to be the suction side of the auxiliary compressor 10. Further, the direction of the refrigerant flowing through the expander 6 is always set to the same direction by switching the second four-way valve 4.

The operation of the heat pump type air conditioning apparatus according to this embodiment will be described below.
First, the cooling operation mode using the outdoor heat exchanger 3 as a radiator and the indoor heat exchanger 8 as an evaporator will be described. The refrigerant flow in the cooling operation mode is indicated by solid line arrows in the figure.
The refrigerant in the cooling operation mode is compressed and discharged at a high temperature and a high pressure by the compressor 1 driven by the motor 12, and is introduced into the outdoor heat exchanger 3 through the first four-way valve 2. In the outdoor heat exchanger 3, since the CO ₂ refrigerant is in a supercritical state, it does not enter a gas-liquid two-phase state but radiates heat to an external fluid such as air or water. Thereafter, the CO ₂ refrigerant is introduced into the pre-expansion valve 5, the expander 6, and the sub-expander 21, and decompressed by the pre-expansion valve 5, the expander 6, and the sub-expander 21. The power recovered by the expander 6 during this decompression is used to drive the auxiliary compressor 10. At this time, for example, the optimum refrigerant amount flowing to the expander 6 is calculated from the high-pressure refrigerant temperature and the high-pressure refrigerant pressure detected at the outlet side of the outdoor heat exchanger 3, and when the volume flow rate is larger than the calculated optimum refrigerant amount The volume flow rate flowing into the expander 6 is decreased by decreasing the torque (generator load) of the machine 22 and increasing the amount of refrigerant flowing through the bypass circuit. On the other hand, when the volume flow rate is smaller than the calculated optimum refrigerant amount, the volume flow rate flowing into the expander 6 is increased by decreasing the opening of the pre-expansion valve 5 and increasing the high-pressure side pressure.
CO ₂ refrigerant decompressed by the pre-expansion valve 5 and the expander 6 CO ₂ refrigerant or sub expander 21 that is decompressed by is guided to the indoor heat exchanger 8 through the second four-way valve 4, It evaporates and absorbs heat in the indoor heat exchanger 8. Indoor cooling is performed by this heat absorption. The evaporated refrigerant is guided to the auxiliary compressor 10 through the second four-way valve 9, supercharged (charged) by the auxiliary compressor 10, and sucked into the compressor 1.

Next, a heating operation mode using the outdoor heat exchanger 3 as an evaporator and the indoor heat exchanger 8 as a radiator will be described. The refrigerant flow in the heating operation mode is indicated by a wavy arrow in the figure.
The refrigerant in the heating operation mode is compressed and discharged at a high temperature and high pressure by the compressor 1 driven by the motor 12, and is guided to the auxiliary compressor 10 through the first four-way valve 2 and the third four-way valve 9 to assist. The compressor 10 further overpressures (expressor). The refrigerant overpressured by the auxiliary compressor 10 is introduced into the indoor heat exchanger 8 through the third four-way valve 9. In the indoor heat exchanger 8, since the CO ₂ refrigerant is in a supercritical state, the CO ₂ refrigerant does not enter a gas-liquid two-phase state but radiates heat to an external fluid such as air or water. Heating is performed. Thereafter, the CO ₂ refrigerant is introduced into the pre-expansion valve 5, the expander 6, and the sub-expander 21, and decompressed by the pre-expansion valve 5, the expander 6, and the sub-expander 21. The power recovered by the expander 6 during this decompression is used to drive the auxiliary compressor 10. At this time, for example, the optimum refrigerant amount flowing to the expander 6 is calculated from the high-pressure refrigerant temperature and the high-pressure refrigerant pressure detected on the outlet side of the indoor heat exchanger 8, and power generation is performed when the volume flow rate is larger than the calculated optimum refrigerant amount. The volume flow rate flowing into the expander 6 is decreased by decreasing the torque (generator load) of the machine 22 and increasing the amount of refrigerant flowing through the bypass circuit. On the other hand, when the volume flow rate is smaller than the calculated optimum refrigerant amount, the volume flow rate flowing into the expander 6 is increased by decreasing the opening of the pre-expansion valve 5 and increasing the high-pressure side pressure.
CO ₂ refrigerant decompressed by the pre-expansion valve 5 and the expander 6 CO reduced in pressure by _second refrigerant or sub expander 21 is guided to the outdoor heat exchanger 3 through the second four-way valve 4, The refrigerant that has evaporated and absorbed heat in the outdoor heat exchanger 3 and has finished evaporation is sucked into the compressor 1 via the first four-way valve 2.

As described above, according to the present embodiment, the expander is configured by adjusting the amount of refrigerant flowing through the bypass circuit by changing the torque of the generator 22 connected to the sub expander 21 (that is, the load of the generator). The amount of refrigerant flowing to the expander 6 can be controlled by changing the opening of the pre-expansion valve 5 and adjusting the high-pressure side pressure. Therefore, power can be recovered efficiently in the expander 6 and higher power can be recovered from the refrigeration cycle by using the power recovered from the sub-expander 21 for power generation by the generator 22.
Further, according to the present embodiment, the compressor 1 that compresses the refrigerant, the expander 6 that recovers power, and the auxiliary compressor 10 are installed separately, and supercharged (charger) by the auxiliary compressor 10 in the cooling operation mode. The expansion unit 6 can be operated as a charger-type expansion unit suitable for cooling, and can be operated as an expansion unit suitable for heating. It can also be operated as a presser type expander.

Hereinafter, a refrigeration cycle apparatus according to another embodiment of the present invention will be described with reference to the drawings for a heat pump type air conditioning apparatus.
FIG. 44 is a configuration diagram of a heat pump air-conditioning type air conditioner according to the present embodiment.
As shown in the figure, the heat pump air-conditioning type air conditioner according to the present embodiment uses a CO ₂ refrigerant as a refrigerant, a compressor 1 having a motor 12, an outdoor heat exchanger 3, an expander 6, It is comprised from the refrigerant circuit which connected the indoor side heat exchanger 8 and the auxiliary compressor 10 with piping.
A sub expander 23 is provided on the inflow side of the expander 6, and a generator 22 is connected to a drive shaft of the sub expander 23.
A bypass circuit that bypasses the sub-expander 23 and the expander 6 is provided in parallel with the sub-expander 23 and the expander 6, and the sub-expander 21 is provided in the bypass circuit, and the drive shaft of the sub-expander 21 Is connected to a generator 22. This bypass circuit is also connected to the second four-way valve 4 in the same manner as the sub-expander 23 and the expander 6.
Here, the generator 22 includes a clutch mechanism connected to either the sub-expander 21 or the sub-expander 23. A flow path valve 25 is provided on the inflow side of the bypass circuit.
Further, the drive shaft of the expander 6 and the drive shaft of the auxiliary compressor 10 are connected, and the auxiliary compressor 10 is driven by the power recovered by the expander 6.
The refrigerant circuit includes a first four-way valve 2 to which a discharge side pipe and a suction side pipe of the compressor 1 are connected, and a second four-way valve to which a discharge side pipe and a suction side pipe of the expander 6 are connected. 4 and a third four-way valve 9 to which the discharge side pipe and the suction side pipe of the auxiliary compressor 10 are connected. In the case of a refrigerant flow in which the outdoor heat exchanger 3 is a radiator and the indoor heat exchanger 8 is an evaporator, the discharge of the auxiliary compressor 10 is performed by switching between the first four-way valve 2 and the third four-way valve 9. The side is configured to be the suction side of the compressor 1. In the case of a refrigerant flow in which the outdoor heat exchanger 3 is an evaporator and the indoor heat exchanger 8 is a radiator, the compressor 1 is switched by switching between the first four-way valve 2 and the third four-way valve 9. The discharge side is configured to be the suction side of the auxiliary compressor 10. Further, the direction of the refrigerant flowing through the expander 6 is always set to the same direction by switching the second four-way valve 4.

The operation of the heat pump type air conditioning apparatus according to this embodiment will be described below.
First, the cooling operation mode using the outdoor heat exchanger 3 as a radiator and the indoor heat exchanger 8 as an evaporator will be described. The refrigerant flow in the cooling operation mode is indicated by solid line arrows in the figure.
The refrigerant in the cooling operation mode is compressed and discharged at a high temperature and a high pressure by the compressor 1 driven by the motor 12, and is introduced into the outdoor heat exchanger 3 through the first four-way valve 2. In the outdoor heat exchanger 3, since the CO ₂ refrigerant is in a supercritical state, it does not enter a gas-liquid two-phase state but radiates heat to an external fluid such as air or water. Thereafter, the CO ₂ refrigerant is introduced into the sub-expander 23 and the expander 6 and decompressed by the sub-expander 23 and the expander 6. The power recovered by the expander 6 during this decompression is used to drive the auxiliary compressor 10. At this time, for example, the optimum refrigerant amount flowing to the expander 6 is calculated from the high-pressure refrigerant temperature and the high-pressure refrigerant pressure detected on the outlet side of the outdoor heat exchanger 3, and when the volume flow rate is larger than the calculated optimum refrigerant amount, The flow rate valve 25 is opened, the generator 22 is connected to the sub-expander 21 side, and the refrigerant flows through the bypass circuit to reduce the volume flow rate flowing into the expander 6. In this case, the sub expander 23 is not operated. Further, it is preferable to change the bypass amount by adjusting the torque of the generator 22. On the other hand, when the volume flow rate is smaller than the calculated optimum refrigerant amount, the flow path valve 25 is closed, the generator 22 is connected to the sub expander 23 side, and the high pressure side pressure is increased to flow into the expander 6. Increase volume flow. In this case, the sub expander 21 is not operated. It is preferable to change the high-pressure side pressure by adjusting the torque of the generator 22.
CO ₂ refrigerant decompressed by the sub-expander 23 and the expander 6, or the sub-expander 21 and CO ₂ refrigerant decompressed by the expander 6, an indoor heat exchanger through the second four-way valve 4 8 evaporates in the indoor heat exchanger 8 and absorbs heat. Indoor cooling is performed by this heat absorption. The evaporated refrigerant is guided to the auxiliary compressor 10 through the second four-way valve 9, supercharged (charged) by the auxiliary compressor 10, and sucked into the compressor 1.

Next, a heating operation mode using the outdoor heat exchanger 3 as an evaporator and the indoor heat exchanger 8 as a radiator will be described. The refrigerant flow in the heating operation mode is indicated by a wavy arrow in the figure.
The refrigerant in the heating operation mode is compressed and discharged at a high temperature and high pressure by the compressor 1 driven by the motor 12, and is guided to the auxiliary compressor 10 through the first four-way valve 2 and the third four-way valve 9 to assist. The compressor 10 further overpressures (expressor). The refrigerant overpressured by the auxiliary compressor 10 is introduced into the indoor heat exchanger 8 through the third four-way valve 9. In the indoor heat exchanger 8, since the CO ₂ refrigerant is in a supercritical state, the CO ₂ refrigerant does not enter a gas-liquid two-phase state but radiates heat to an external fluid such as air or water. Heating is performed. Thereafter, the CO ₂ refrigerant is introduced into the sub-expander 23 and the expander 6 and decompressed by the sub-expander 23 and the expander 6. The power recovered by the expander 6 during this decompression is used to drive the auxiliary compressor 10. At this time, for example, the optimum refrigerant amount flowing to the expander 6 is calculated from the high-pressure refrigerant temperature and the high-pressure refrigerant pressure detected at the outlet side of the indoor heat exchanger 8, and when the volume flow rate is larger than the calculated optimum refrigerant amount, The flow rate valve 25 is opened, the generator 22 is connected to the sub-expander 21 side, and the refrigerant flows through the bypass circuit to reduce the volume flow rate flowing into the expander 6. In this case, the sub expander 23 is not operated. Further, it is preferable to change the bypass amount by adjusting the torque of the generator 22. On the other hand, when the volume flow rate is smaller than the calculated optimum refrigerant amount, the flow path valve 25 is closed, the generator 22 is connected to the sub expander 23 side, and the high pressure side pressure is increased to flow into the expander 6. Increase volume flow. In this case, the sub expander 21 is not operated. It is preferable to change the high-pressure side pressure by adjusting the torque of the generator 22.
CO ₂ refrigerant decompressed by the sub-expander 23 and the expander 6, or the sub-expander 21 and CO ₂ refrigerant decompressed by the expander 6, an outdoor heat exchanger via the second four-way valve 4 3, the refrigerant evaporating and absorbing heat in the outdoor heat exchanger 3, and the evaporated refrigerant is sucked into the compressor 1 through the first four-way valve 2.

As described above, according to the present embodiment, the amount of refrigerant flowing through the expander 6 is adjusted by adjusting the amount of refrigerant flowing through the bypass circuit by opening the on-off valve 25 and connecting the generator 22 to the sub-expander 21. On the other hand, by adjusting the high-pressure side pressure by changing the torque of the generator 24 connected to the sub-expander 23 (ie, the load of the generator) by closing the on-off valve 25, the expander 6 can be controlled. Accordingly, power can be efficiently recovered in the expander 6, and the power recovered from the sub-expander 21 or the sub-expander 23 is used for power generation by the generator 22 and the generator 24. Power recovery can be performed.
Further, according to the present embodiment, the compressor 1 that compresses the refrigerant, the expander 6 that recovers power, and the auxiliary compressor 10 are installed separately, and supercharged (charger) by the auxiliary compressor 10 in the cooling operation mode. The expansion unit 6 can be operated as a charger-type expansion unit suitable for cooling, and can be operated as an expansion unit suitable for heating. It can also be operated as a presser type expander.

Hereinafter, a refrigeration cycle apparatus according to another embodiment of the present invention will be described with reference to the drawings for a heat pump type air conditioning apparatus.
FIG. 45 is a configuration diagram of a heat pump type air conditioning apparatus according to the present embodiment.
As shown in the figure, the heat pump air-conditioning type air conditioner according to the present embodiment uses a CO ₂ refrigerant as a refrigerant, a compressor 1 having a motor 12, an outdoor heat exchanger 3, an expander 6, It is comprised from the refrigerant circuit which connected the indoor side heat exchanger 8 and the auxiliary compressor 10 with piping.
A sub-expander 23 is provided on the discharge side of the expander 6, and a generator 22 is connected to the drive shaft of the sub-expander 23.
A bypass circuit that bypasses the sub-expander 23 and the expander 6 is provided in parallel with the sub-expander 23 and the expander 6, and the sub-expander 21 is provided in the bypass circuit, and the drive shaft of the sub-expander 21 Is connected to a generator 22. This bypass circuit is also connected to the second four-way valve 4 in the same manner as the sub-expander 23 and the expander 6.
Here, the generator 22 includes a clutch mechanism connected to either the sub-expander 21 or the sub-expander 23. A flow path valve 25 is provided on the inflow side of the bypass circuit.
Further, the drive shaft of the expander 6 and the drive shaft of the auxiliary compressor 10 are connected, and the auxiliary compressor 10 is driven by the power recovered by the expander 6.
The refrigerant circuit includes a first four-way valve 2 to which a discharge side pipe and a suction side pipe of the compressor 1 are connected, and a second four-way valve to which a discharge side pipe and a suction side pipe of the expander 6 are connected. 4 and a third four-way valve 9 to which the discharge side pipe and the suction side pipe of the auxiliary compressor 10 are connected. In the case of a refrigerant flow in which the outdoor heat exchanger 3 is a radiator and the indoor heat exchanger 8 is an evaporator, the discharge of the auxiliary compressor 10 is performed by switching between the first four-way valve 2 and the third four-way valve 9. The side is configured to be the suction side of the compressor 1. In the case of a refrigerant flow in which the outdoor heat exchanger 3 is an evaporator and the indoor heat exchanger 8 is a radiator, the compressor 1 is switched by switching between the first four-way valve 2 and the third four-way valve 9. The discharge side is configured to be the suction side of the auxiliary compressor 10. Further, the direction of the refrigerant flowing through the expander 6 is always set to the same direction by switching the second four-way valve 4.

The operation of the heat pump type air conditioning apparatus according to this embodiment will be described below.
First, the cooling operation mode using the outdoor heat exchanger 3 as a radiator and the indoor heat exchanger 8 as an evaporator will be described. The refrigerant flow in the cooling operation mode is indicated by solid line arrows in the figure.
The refrigerant in the cooling operation mode is compressed and discharged at a high temperature and a high pressure by the compressor 1 driven by the motor 12, and is introduced into the outdoor heat exchanger 3 through the first four-way valve 2. In the outdoor heat exchanger 3, since the CO ₂ refrigerant is in a supercritical state, it does not enter a gas-liquid two-phase state but radiates heat to an external fluid such as air or water. Thereafter, the CO ₂ refrigerant is introduced into the expander 6 and the sub-expander 23 and decompressed by the expander 6 and the sub-expander 23. The power recovered by the expander 6 during this decompression is used to drive the auxiliary compressor 10. At this time, for example, the optimum refrigerant amount flowing to the expander 6 is calculated from the high-pressure refrigerant temperature and the high-pressure refrigerant pressure detected on the outlet side of the outdoor heat exchanger 3, and when the volume flow rate is larger than the calculated optimum refrigerant amount, The flow rate valve 25 is opened, the generator 22 is connected to the sub-expander 21 side, and the refrigerant flows through the bypass circuit to reduce the volume flow rate flowing into the expander 6. In this case, the sub expander 23 is not operated. Further, it is preferable to change the bypass amount by adjusting the torque of the generator 22. On the other hand, when the volume flow rate is smaller than the calculated optimum refrigerant amount, the flow path valve 25 is closed, the generator 22 is connected to the sub expander 23 side, and the low pressure side pressure is lowered to flow into the expander 6. Increase volume flow. In this case, the sub expander 21 is not operated. Moreover, it is preferable to change the low pressure side pressure by adjusting the torque of the generator 22.
CO ₂ refrigerant decompressed by the sub-expander 23 and the expander 6, or the sub-expander 21 and CO ₂ refrigerant decompressed by the expander 6, an indoor heat exchanger through the second four-way valve 4 8 evaporates in the indoor heat exchanger 8 and absorbs heat. Indoor cooling is performed by this heat absorption. The evaporated refrigerant is guided to the auxiliary compressor 10 through the second four-way valve 9, supercharged (charged) by the auxiliary compressor 10, and sucked into the compressor 1.

Next, a heating operation mode using the outdoor heat exchanger 3 as an evaporator and the indoor heat exchanger 8 as a radiator will be described. The refrigerant flow in the heating operation mode is indicated by a wavy arrow in the figure.
The refrigerant in the heating operation mode is compressed and discharged at a high temperature and high pressure by the compressor 1 driven by the motor 12, and is guided to the auxiliary compressor 10 through the first four-way valve 2 and the third four-way valve 9 to assist. The compressor 10 further overpressures (expressor). The refrigerant overpressured by the auxiliary compressor 10 is introduced into the indoor heat exchanger 8 through the third four-way valve 9. In the indoor heat exchanger 8, since the CO ₂ refrigerant is in a supercritical state, the CO ₂ refrigerant does not enter a gas-liquid two-phase state but radiates heat to an external fluid such as air or water. Heating is performed. Thereafter, the CO ₂ refrigerant is introduced into the expander 6 and the sub-expander 23 and decompressed by the expander 6 and the sub-expander 23. The power recovered by the expander 6 during this decompression is used to drive the auxiliary compressor 10. At this time, for example, the optimum refrigerant amount flowing to the expander 6 is calculated from the high-pressure refrigerant temperature and the high-pressure refrigerant pressure detected at the outlet side of the indoor heat exchanger 8, and when the volume flow rate is larger than the calculated optimum refrigerant amount, The flow rate valve 25 is opened, the generator 22 is connected to the sub-expander 21 side, and the refrigerant flows through the bypass circuit to reduce the volume flow rate flowing into the expander 6. In this case, the sub expander 23 is not operated. Further, it is preferable to change the bypass amount by adjusting the torque of the generator 22. On the other hand, when the volume flow rate is smaller than the calculated optimum refrigerant amount, the flow path valve 25 is closed, the generator 22 is connected to the sub expander 23 side, and the low pressure side pressure is lowered to flow into the expander 6. Increase volume flow. In this case, the sub expander 21 is not operated. Moreover, it is preferable to change the low pressure side pressure by adjusting the torque of the generator 22.
CO ₂ refrigerant decompressed by the sub-expander 23 and the expander 6, or the sub-expander 21 and CO ₂ refrigerant decompressed by the expander 6, an outdoor heat exchanger via the second four-way valve 4 3, the refrigerant evaporating and absorbing heat in the outdoor heat exchanger 3, and the evaporated refrigerant is sucked into the compressor 1 through the first four-way valve 2.

As described above, according to the present embodiment, the amount of refrigerant flowing through the expander 6 is adjusted by adjusting the amount of refrigerant flowing through the bypass circuit by opening the on-off valve 25 and connecting the generator 22 to the sub-expander 21. On the other hand, by adjusting the low pressure side pressure by changing the torque of the generator 24 connected to the sub-expander 23 (ie, the load of the generator) by closing the on-off valve 25, the expander 6 can be controlled. Accordingly, power can be efficiently recovered in the expander 6, and the power recovered from the sub-expander 21 or the sub-expander 23 is used for power generation by the generator 22 and the generator 24. Power recovery can be performed.
Further, according to the present embodiment, the compressor 1 that compresses the refrigerant, the expander 6 that recovers power, and the auxiliary compressor 10 are installed separately, and supercharged (charger) by the auxiliary compressor 10 in the cooling operation mode. The expansion unit 6 can be operated as a charger-type expansion unit suitable for cooling, and can be operated as an expansion unit suitable for heating. It can also be operated as a presser type expander.

  In the said Example, although demonstrated using the heat pump type air conditioning air conditioner, the outdoor side heat exchanger 3 was made into the 1st heat exchanger, the indoor side heat exchanger 8 was made into the 2nd heat exchanger, and these 1st The other refrigeration cycle apparatus using the heat exchanger 1 or the second heat exchanger for a hot / cold water heater or a regenerator may be used.

1 is a block diagram of a heat pump type air conditioning apparatus according to an embodiment of the present invention. The block diagram of the heat pump type air conditioning air conditioner by other Example of this invention The figure which shows an example of the fixed density ratio at the time of air_conditioning | cooling and heating in the charger system in which the discharge side of an auxiliary compressor becomes the suction side of a compressor, and the expresser system in which the discharge side of a compressor becomes the suction side of an auxiliary compressor The figure which shows the comparison of the optimal COP ratio of the switching system of the charger and expressor by this invention, and a comparative example The figure which shows the relationship between the frequency of a compressor and an auxiliary compressor at the time of setting the cooling operation rated frequency of an auxiliary compressor to the same frequency of 37 Hz as the cooling operation rated frequency of a compressor. The block diagram of the heat pump type air conditioner by the other Example of this invention The block diagram of the heat pump type air conditioning air conditioner by other Example of this invention The block diagram of the heat pump type air conditioner by the other Example of this invention The block diagram of the heat pump type air conditioning air conditioner by other Example of this invention The block diagram of the heat pump type air conditioner by the other Example of this invention The block diagram of the heat pump type air conditioning air conditioner by other Example of this invention The block diagram of the heat pump type air conditioner by the other Example of this invention The block diagram of the heat pump type air conditioning air conditioner by other Example of this invention The block diagram of the heat pump type air conditioner by the other Example of this invention The block diagram of the heat pump type air conditioning air conditioner by other Example of this invention The block diagram of the heat pump type air conditioner by the other Example of this invention The block diagram of the heat pump type air conditioning air conditioner by other Example of this invention The block diagram of the heat pump type air conditioner by the other Example of this invention The block diagram of the heat pump type air conditioning air conditioner by other Example of this invention The block diagram of the heat pump type air conditioner by the other Example of this invention The block diagram of the heat pump type air conditioning air conditioner by other Example of this invention The block diagram of the heat pump type air conditioning air conditioner by other Example of this invention The block diagram of the heat pump type air conditioning air conditioner by other Example of this invention The block diagram of the heat pump type air conditioning air conditioner by other Example of this invention The block diagram of the heat pump type air conditioning air conditioner by other Example of this invention The block diagram of the heat pump type air conditioning air conditioner by other Example of this invention The block diagram of the heat pump type air conditioning air conditioner by other Example of this invention The block diagram of the heat pump type air conditioning air conditioner by other Example of this invention The block diagram of the heat pump type air conditioning air conditioner by other Example of this invention The block diagram of the heat pump type air conditioning air conditioner by other Example of this invention The block diagram of the heat pump type air conditioning air conditioner by other Example of this invention The block diagram of the heat pump type air conditioning air conditioner by other Example of this invention The block diagram of the heat pump type air conditioning air conditioner by other Example of this invention The block diagram of the heat pump type air conditioning air conditioner by other Example of this invention The block diagram of the heat pump type air conditioning air conditioner by other Example of this invention The block diagram of the heat pump type air conditioning air conditioner by other Example of this invention The block diagram of the heat pump type air conditioning air conditioner by other Example of this invention The block diagram of the heat pump type air conditioning air conditioner by other Example of this invention The block diagram of the heat pump type air conditioning air conditioner by other Example of this invention The block diagram of the heat pump type air conditioning air conditioner by other Example of this invention The block diagram of the heat pump type air conditioning air conditioner by other Example of this invention The block diagram of the heat pump type air conditioning air conditioner by other Example of this invention The block diagram of the heat pump type air conditioning air conditioner by other Example of this invention The block diagram of the heat pump type air conditioning air conditioner by other Example of this invention The block diagram of the heat pump type air conditioning air conditioner by other Example of this invention

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Compressor 2 1st 4 way valve 3 Outdoor heat exchanger 4 2nd 4 way valve 5 Pre-expansion valve 6 Expander 7 Bypass valve 8 Indoor heat exchanger 9 3rd 4 way valve 10 Auxiliary compressor 11 Motor 13 1st check valve Assembly device 13a, 13b, 13c, 13d Check valve 15 Second check valve assembly device 15a, 15b, 15c, 15d Check valve 21 First auxiliary expander 22, 24 Generator 23 Second auxiliary expander 25 Pre-expansion Valve 26 Bypass expansion valve 27 Common generator 28 Inlet flow path valve 36 Sliding vane expander 37 Vane

Claims (11)

  A refrigeration cycle apparatus that uses carbon dioxide as a refrigerant, includes a compressor, a first heat exchanger, an expander, and a second heat exchanger, and uses the power recovered by the expander to drive the compressor. A refrigeration cycle apparatus comprising a sub-expander in parallel with the expander, and a generator connected to the sub-expander. A refrigeration cycle apparatus that uses carbon dioxide as a refrigerant, includes a compressor, a first heat exchanger, an expander, and a second heat exchanger, and uses the power recovered by the expander to drive the compressor. Te, refrigerating cycle apparatus characterized in that the sub-expander is provided on the suction side of the expander connected to a generator. A refrigeration cycle apparatus that uses carbon dioxide as a refrigerant, includes a compressor, a first heat exchanger, an expander, and a second heat exchanger, and uses the power recovered by the expander to drive the compressor. Te, refrigerating cycle apparatus characterized in that the sub-expander is provided on the discharge side of the expander connected to a generator.   A refrigeration cycle apparatus that uses carbon dioxide as a refrigerant, includes a compressor, a first heat exchanger, an expander, and a second heat exchanger, and uses the power recovered by the expander to drive the compressor. A first sub expander is provided on the suction side of the expander, a second sub expander is provided in parallel with the expander and the first sub expander, and the first sub expander and the second sub expander are provided. A refrigeration cycle apparatus in which a generator is connected to each machine.   A refrigeration cycle apparatus that uses carbon dioxide as a refrigerant, includes a compressor, a first heat exchanger, an expander, and a second heat exchanger, and uses the power recovered by the expander to drive the compressor. A refrigeration cycle apparatus comprising a sub-expander on the suction side of the expander, a bypass flow path provided in parallel with the expander and the sub-expander, and a bypass valve provided in the bypass flow path. .   A refrigeration cycle apparatus that uses carbon dioxide as a refrigerant, includes a compressor, a first heat exchanger, an expander, and a second heat exchanger, and uses the power recovered by the expander to drive the compressor. A refrigeration cycle apparatus comprising: a pre-expansion valve on the suction side of the expander; a sub-expander in parallel with the expander and the pre-expansion valve; and a generator connected to the sub-expander. .   A refrigeration cycle apparatus that uses carbon dioxide as a refrigerant, includes a compressor, a first heat exchanger, an expander, and a second heat exchanger, and uses the power recovered by the expander to drive the compressor. A first sub-expander on the suction side of the expander, a second sub-expander in parallel with the expander and the first sub-expander, and a generator connected to the first sub-expander. A refrigeration cycle apparatus comprising: a generator connected to the second sub expander, wherein the generator includes a clutch mechanism connected to one of the first sub expander and the second sub expander. . A refrigeration cycle apparatus that uses carbon dioxide as a refrigerant, includes a compressor, a first heat exchanger, an expander, and a second heat exchanger, and uses the power recovered by the expander to drive the compressor. A first sub-expander on the discharge side of the expander, a second sub- expander in parallel with the expander and the first sub-expander, and a generator connected to the first sub-expander. A refrigeration cycle apparatus comprising: a generator connected to the second sub expander, wherein the generator includes a clutch mechanism connected to one of the first sub expander and the second sub expander.   An auxiliary compressor is provided on the suction side of the compressor or the discharge side of the compressor, and the power recovered by the expander is used as power for driving the auxiliary compressor instead of the compressor. The refrigeration cycle apparatus according to any one of claims 1 to 8.   A first four-way valve connected to a discharge side pipe and a suction side pipe of the compressor; and a second four-way valve connected to a discharge side pipe and a suction side pipe of the expander and the sub-expander. The refrigerant discharged from the compressor is selectively flowed to the first heat exchanger or the second heat exchanger by the first four-way valve, and the expander and the sub-flow are flown by the second four-way valve. The refrigeration cycle apparatus according to any one of claims 1 to 8, wherein the direction of the refrigerant flowing through the expander is always the same direction.   A first four-way valve to which a discharge side pipe and a suction side pipe of the compressor and the auxiliary compressor are connected, and a second side to which a discharge side pipe and a suction side pipe of the expander and the sub expander are connected. And a refrigerant discharged from the compressor and the auxiliary compressor is selectively flowed to the second heat exchanger or the second heat exchanger by the first four-way valve, and the first 10. The refrigeration cycle apparatus according to claim 9, wherein the direction of the refrigerant flowing through the expander and the sub expander is always set to the same direction by a two-way valve.

Images