JP2010159967A - Heat pump device and outdoor unit for the heat pump device - Google Patents

Heat pump device and outdoor unit for the heat pump device Download PDF

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JP2010159967A
JP2010159967A JP2010096148A JP2010096148A JP2010159967A JP 2010159967 A JP2010159967 A JP 2010159967A JP 2010096148 A JP2010096148 A JP 2010096148A JP 2010096148 A JP2010096148 A JP 2010096148A JP 2010159967 A JP2010159967 A JP 2010159967A
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Japan
Prior art keywords
refrigerant
heat exchanger
compressor
expansion valve
heat
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JP2010096148A
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Japanese (ja)
Inventor
Masanori Aoki
Tetsuji Nanatane
Makoto Saito
Fumitake Unezaki
Masato Yosomiya
哲二 七種
正人 四十宮
史武 畝崎
正則 青木
信 齊藤
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Mitsubishi Electric Corp
三菱電機株式会社
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Abstract

<P>PROBLEM TO BE SOLVED: To obtain a heat pump device capable of exhibiting a sufficient heating capacity even in a cold area where an outside air temperature is lowered to -10°C or lower by improving the heating capacity compared with a conventional gas injection cycle. <P>SOLUTION: The heat pump device includes: a heat exchanger (9) applying the heat of a refrigerant flowing from a heat exchanger (6) toward a heat exchanger (12) to a refrigerant flowing from the heat exchanger (12) toward a compressor (3); a bypass path (13) allowing part of the refrigerant flowing from the heat exchanger (6) toward the heat exchanger (12) to join the refrigerant sucked to the compressor (3) through the heat exchanger (12) and compressed to intermediate pressure; an expansion valve (14) provided in the bypass path (13) to lower the pressure of the refrigerant flowing through the bypass path (13); and a heat exchanger (10) provided in the bypass path (13) to apply the heat of the refrigerant flowing from the heat exchanger (6) toward the heat exchanger (12) to the refrigerant flowing through the bypass path (13). <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a heat pump device and an outdoor unit of the heat pump device, and more particularly, to a heat pump device and an outdoor unit of the heat pump device that perform gas injection to improve the heating capability at a low outside air temperature.

As a conventional refrigeration air conditioner, a gas-liquid separator is installed at the intermediate pressure part between the condenser and the evaporator, and the gas refrigerant separated by the gas-liquid separator is injected into the intermediate pressure part of the compressor to increase the heating capacity. (For example, refer to Patent Document 1).
Also, instead of the gas-liquid separator, a part of the high-pressure liquid refrigerant is bypassed, and after reducing the pressure, heat exchange with the high-pressure liquid refrigerant is carried out to evaporate gas, and then injected into the compressor to improve the heating capacity. There is something like this (see, for example, Patent Document 2).
In addition, there is a configuration in which a liquid receiver is provided in an intermediate pressure portion between the condenser and the evaporator so that heat is exchanged between the refrigerant in the liquid receiver and the refrigerant sucked by the compressor (for example, see Patent Document 3).

JP 2001-304714 A JP 2000-274859 A JP 2001-174091 A

However, the conventional refrigeration and air-conditioning apparatus has the following problems.
First, as in the conventional example described in Patent Document 1, when performing injection with a gas-liquid separator, the amount of liquid in the gas-liquid separator varies depending on the amount of injection, and accordingly, the amount of liquid refrigerant in the refrigeration cycle is distributed. Fluctuated and the operation became unstable.
When the injected gas refrigerant flow rate and the gas refrigerant flow rate of the two-phase refrigerant flowing into the gas-liquid separator are balanced, only the liquid refrigerant flows out to the evaporator side, Although the amount of liquid refrigerant is stable, the flow rate of injected refrigerant decreases, and when the refrigerant flow rate becomes smaller than the gas refrigerant flow rate flowing into the gas-liquid separator, the gas refrigerant also flows out to the evaporator side. Since the gas flows out from the bottom of the vessel, the liquid in the gas-liquid separator is almost discharged.
On the contrary, when the flow rate of the injected refrigerant increases, the gas refrigerant is insufficient, so the liquid refrigerant is also injected into the gas refrigerant, and the liquid flows out from the top of the gas-liquid separator. The liquid inside is almost full.

The injection flow rate is likely to fluctuate depending on the high and low pressures of the refrigeration cycle, the pressure of the gas-liquid separator, the operating capacity of the compressor, etc., so the injection flow rate rarely matches the gas refrigerant flow rate flowing into the gas-liquid separator. The amount of liquid refrigerant in the gas-liquid separator is almost zero or full, and the amount of refrigerant in the gas-liquid separator is likely to vary depending on the operating conditions. As a result, the refrigerant amount distribution in the refrigeration cycle fluctuates and operation instability is likely to occur.
Such operation instability due to fluctuations in the amount of refrigerant in the gas-liquid separator takes the form of bypassing a part of the high-pressure liquid refrigerant and injecting it as in the conventional example described in Patent Document 2. Is solved because there is no. However, the following problems remain even if this format is adopted.

In general, in a refrigeration cycle in which gas injection is performed, the heating capacity can be increased as the injection flow rate is increased and the refrigerant flow rate discharged from the compressor and flowing into the indoor heat exchanger is increased.
However, when the injection flow rate is increased, the liquid refrigerant is also injected into the gas refrigerant, the compressor discharge temperature is lowered, and the refrigerant temperature at the inlet of the indoor heat exchanger is also lowered. Heat exchange capacity is reduced. Therefore, there exists an injection flow rate that maximizes the heating capacity in balance between the refrigerant flow rate and the heat exchange capacity.
In a normal air heat source type heat pump refrigeration air conditioner, the heating capacity is lowered in a cold district where the outside air is -10 ° C. or less, and sufficient heating operation cannot be performed. However, in the gas injection cycle as described above, there is a problem that the heating capacity is limited and sufficient heating operation cannot be performed.

Further, even in the conventional example described in Patent Document 3, there is a problem that the circuit configuration does not have an effect of increasing the heating capacity, and similarly, the heating capacity in a cold region is lowered and sufficient heating operation cannot be performed.
In view of the above problems, the present invention improves the heating capacity of the heat pump apparatus and the outdoor unit of the heat pump apparatus as compared with the conventional gas injection cycle, and has sufficient heating capacity even in a cold district where the outside air is -10 ° C or lower. It aims at obtaining the outdoor unit of the heat pump apparatus and heat pump apparatus which can be exhibited.

  The heat pump device according to the present invention includes an evaporator (12) that absorbs heat of air into the refrigerant, a compressor (3) that sucks the refrigerant from the evaporator (12), and the compressor (3). A load-side heat exchanger (6) for supplying the heat of the refrigerant to the load-side medium, and a first expansion valve (11) for reducing the pressure of the refrigerant flowing from the load-side heat exchanger (6) to the evaporator (12) ) And a main refrigerant circuit connected to circulate the refrigerant, and in the heat pump device using the heat radiated from the load side heat exchanger (6), the load side heat exchanger (6) A first internal heat exchanger (9) that applies heat of the refrigerant flowing from the evaporator (12) toward the evaporator (12) to the refrigerant flowing from the evaporator (12) toward the compressor (3), and the load Cooling flowing from the side heat exchanger (6) toward the evaporator (12) A bypass path (13) that joins the refrigerant that has been sucked into the compressor (3) through the evaporator (12) and compressed to an intermediate pressure, and the bypass path (13), A third expansion valve (14) for reducing the pressure of the refrigerant flowing through the bypass path (13), the main refrigerant circuit, and the bypass path (13) are provided in the evaporation from the load side heat exchanger (6). A second internal heat exchanger (10) that gives heat of the refrigerant flowing toward the vessel (12) to the refrigerant flowing through the bypass path (13), the first expansion valve (11), and the third And a control device (15) for controlling the opening degree of the expansion valve (14).

  As described above, according to the present invention, the heat exchanger (6) exhibits sufficient heat exchange performance, thereby ensuring sufficient heating capacity even under conditions in which the heating capacity is likely to decrease due to low outside air conditions. Can do.

It is a refrigerant circuit figure of the refrigerating and air-conditioning apparatus of Embodiment 1 which concerns on this invention. It is PH diagram showing the driving | running state at the time of the heating operation of the refrigerating air conditioner. It is PH diagram showing the driving | running state at the time of air_conditionaing | cooling operation of the same refrigeration air conditioner. It is a flow figure showing control operation at the time of heating operation of the refrigerating air-conditioner. It is a flowchart which shows the control action at the time of the air_conditionaing | cooling operation of the same refrigeration air conditioner. It is a PH diagram showing the driving | running state at the time of gas injection implementation of the refrigerating air conditioner. It is a figure showing the temperature change of the condenser at the time of gas injection implementation of the refrigerating air conditioner. It is a figure showing the operation characteristic at the time of the gas injection flow rate change of the refrigerating air-conditioner. It is a figure showing the difference in the operation characteristic by the presence or absence of the 1st internal heat exchanger of the refrigerating air-conditioning apparatus. It is another figure showing the operation characteristic at the time of the gas injection flow rate change of the refrigeration air conditioner. It is a refrigerant circuit figure of the refrigerating and air-conditioning apparatus of Embodiment 2 which concerns on this invention.

Embodiment 1 FIG.
1 is a refrigerant circuit diagram of a refrigerating and air-conditioning apparatus (heat pump apparatus) according to Embodiment 1 of the present invention.
In FIG. 1, an outdoor unit 1 includes a compressor 3, a four-way valve 4 that switches between heating and cooling, an outdoor heat exchanger 12 (evaporator (12)), a first expansion valve 11 that is a decompression device, a first 2 an internal heat exchanger 10, a first internal heat exchanger 9, a second expansion valve 8 that is a pressure reducing device, an injection circuit 13 (bypass path (13)), and a third expansion valve 14 that is a pressure reducing device for injection. ing.
The compressor 3 is of a type in which the rotation speed is controlled by an inverter and the capacity is controlled, and has a structure capable of injecting the refrigerant supplied from the injection circuit 13 into the compression chamber in the compressor 3.

The first expansion valve 11, the second expansion valve 8, and the third expansion valve 14 are electronic expansion valves whose opening degree is variably controlled. The outdoor heat exchanger 12 exchanges heat with the outside air blown by a fan or the like.
An indoor heat exchanger 6 (load side heat exchanger (6)) is mounted in the indoor unit 2. The gas pipe 5 and the liquid pipe 7 are connecting pipes that connect the outdoor unit 1 and the indoor unit 2. R410A, which is an HFC mixed refrigerant, is used as the refrigerant of this refrigeration air conditioner.

  A measurement control device 15 and temperature sensors 16 are installed in the outdoor unit 1. The temperature sensor 16 a is on the discharge side of the compressor 3, the temperature sensor 16 b is between the outdoor heat exchanger 12 and the four-way valve 4, the temperature sensor 16 c is on the refrigerant flow path in the middle of the outdoor heat exchanger 12, and the temperature sensor 16 d is outdoor heat. Between the exchanger 12 and the first expansion valve 11, a temperature sensor 16 e is provided between the first internal heat exchanger 9 and the second expansion valve 8, and a temperature sensor 16 f is provided on the suction side of the compressor 3. Measure the refrigerant temperature. The temperature sensor 16g measures the outside air temperature around the outdoor unit 1.

  Temperature sensors 16 h, 16 i, 16 j are installed in the indoor unit 2, the temperature sensor 16 h is on the refrigerant flow path in the middle part of the indoor heat exchanger 6, and the temperature sensor 16 i is connected to the indoor heat exchanger 6 and the liquid pipe 7. The temperature of the refrigerant at each installation location is measured. The temperature sensor 16j measures the temperature of air taken into the indoor heat exchanger 6. When the heat medium serving as a load is another medium such as water, the temperature sensor 16j measures the inflow temperature of the medium.

The temperature sensors 16c and 16h can detect the refrigerant saturation temperature at high and low pressure by detecting the refrigerant temperature in the gas-liquid two-phase state in the middle of the heat exchanger.
In addition, the measurement control device 15 in the outdoor unit 1 is based on the measurement information of the temperature sensor 16 and the operation content instructed by the user of the refrigeration air conditioner, the operation method of the compressor 3, the flow path switching of the four-way valve 4, the outdoor It controls the fan air flow rate of the heat exchanger 12, the opening degree of each expansion valve, and the like.

Next, the operation of this refrigeration air conditioner will be described.
First, the operation during the heating operation will be described with reference to the PH diagrams during the heating operation shown in FIGS.
During the heating operation, the flow path of the four-way valve 4 is set in the direction of the solid line in FIG. The high-temperature and high-pressure gas refrigerant (point 1 in FIG. 2) discharged from the compressor 3 flows out of the outdoor unit 1 through the four-way valve 4 and flows into the indoor unit 2 through the gas pipe 5. Then, it flows into the indoor heat exchanger 6 and condenses and liquefies while dissipating heat in the indoor heat exchanger 6 serving as a condenser to become a high-pressure and low-temperature liquid refrigerant (point 2 in FIG. 2). Heating is performed by applying heat radiated from the refrigerant to a load-side medium such as air or water on the load side.

The high-pressure and low-temperature refrigerant that has exited the indoor heat exchanger 6 flows into the outdoor unit 1 via the liquid pipe 7, and after being slightly decompressed by the second expansion valve 8 (point 3 in FIG. 2), 1 Heat is applied to the low-temperature refrigerant sucked into the compressor 3 by the internal heat exchanger 9 to cool it (point 4 in FIG. 2).
Then, after partially bypassing the refrigerant to the injection circuit 13, the second internal heat exchanger 10 exchanges heat with the refrigerant that has been bypassed by the injection circuit 13 and depressurized by the third expansion valve 14 to a low temperature, and further cooled. (5 in FIG. 2). Thereafter, the refrigerant is depressurized to a low pressure by the first expansion valve 11 to become a two-phase refrigerant (point 6 in FIG. 2), and then flows into the outdoor heat exchanger 12 serving as an evaporator, where it absorbs heat and is evaporated and gasified (FIG. 2). 2 points 7). Thereafter, the heat is exchanged with the high-pressure refrigerant in the first internal heat exchanger 9 through the four-way valve 4, further heated (point 8 in FIG. 2), and sucked into the compressor 3.

On the other hand, the refrigerant bypassed to the injection circuit 13 is depressurized to the intermediate pressure by the third expansion valve 14 to become a low-temperature two-phase refrigerant (point 9 in FIG. 2), and then the high-pressure refrigerant in the second internal heat exchanger 10. The heat is exchanged and heated (point 10 in FIG. 2) and injected into the compressor 3.
Inside the compressor 3, the sucked refrigerant (point 8 in FIG. 2) is compressed and heated to an intermediate pressure (point 11 in FIG. 2), and then merged with the refrigerant to be injected and the temperature is lowered (FIG. 2). Point 12), compressed to high pressure and discharged (point 1 in FIG. 2).

Next, the operation during the cooling operation will be described based on the PH diagrams during the cooling operation shown in FIGS. 1 and 3.
During the cooling operation, the flow path of the four-way valve 4 is set in the direction of the dotted line in FIG. Then, the high-temperature and high-pressure gas refrigerant (point 1 in FIG. 3) discharged from the compressor 3 flows into the outdoor heat exchanger 12 serving as a condenser through the four-way valve 4, where it condenses and liquefies while radiating heat. (Refer to point 2 in FIG. 3). The refrigerant leaving the outdoor heat exchanger 12 is slightly decompressed by the first expansion valve 11 (point 3 in FIG. 3), and then exchanges heat with the low-temperature refrigerant flowing through the injection circuit 13 by the second internal heat exchanger 10. The refrigerant is cooled (point 4 in FIG. 3), and after a part of the refrigerant is bypassed to the injection circuit 13, the first internal heat exchanger 9 continues to exchange heat with the refrigerant sucked into the compressor 3 and is cooled (FIG. 3). 3 points 5).

Thereafter, the pressure is reduced to a low pressure by the second expansion valve 8 to become a two-phase refrigerant (point 6 in FIG. 3), and then flows out of the outdoor unit 1 and flows into the indoor unit 2 through the liquid pipe 7. And it flows in the indoor heat exchanger 6 used as an evaporator, absorbs heat there, and supplies cold heat to a load side medium such as air or water on the indoor unit 2 side while evaporating gas (7 in FIG. 3).
The low-pressure gas refrigerant that has exited the indoor heat exchanger 6 exits the indoor unit 2, flows into the outdoor unit 1 through the gas pipe 5, passes through the four-way valve 4, and then enters the high-pressure refrigerant in the first internal heat exchanger 9. After heat exchange and heating (point 8 in FIG. 3), the air is sucked into the compressor 3.

On the other hand, the refrigerant bypassed to the injection circuit 13 is decompressed to the intermediate pressure by the third expansion valve 14 to become a low-temperature two-phase refrigerant (point 9 in FIG. 3), and then the high-pressure refrigerant in the second internal heat exchanger 10. The heat is exchanged and heated (point 10 in FIG. 3) and injected into the compressor 3. Inside the compressor 3, the sucked refrigerant (point 8 in FIG. 3) is compressed and heated to an intermediate pressure (point 11 in FIG. 3), and then merged with the refrigerant to be injected and after the temperature drops (FIG. 3). Point 12), compressed again to high pressure and discharged (point 1 in FIG. 3).
The PH diagram during the cooling operation is almost the same as that during the heating operation, and the same operation can be realized in either operation mode.

Next, the operation control operation in this refrigeration air conditioner will be described.
First, the control operation during the heating operation will be described based on the flowchart of FIG.
During the heating operation, first, the capacity of the compressor 3, the opening of the first expansion valve 11, the opening of the second expansion valve 8, and the opening of the third expansion valve 14 are set to initial values (step S1).
Then, when a predetermined time has elapsed (step S2), the actuators corresponding to the operating state are controlled as follows.
The capacity of the compressor 3 is basically controlled such that the air temperature measured by the temperature sensor 16j of the indoor unit 2 becomes a temperature set by the user of the refrigeration air conditioner.

That is, the air temperature of the indoor unit 2 is compared with the set value (step S3). When the air temperature is equal to or close to the set temperature, the capacity of the compressor 3 is maintained as it is, and the process proceeds to the next step.
When the air temperature is significantly lower than the set temperature, the capacity of the compressor 3 is increased. When the air temperature is close to the set temperature, the capacity of the compressor 3 is maintained as it is, and the air When the temperature becomes higher than the set temperature, the capacity of the compressor 3 is changed so that the capacity of the compressor 3 is reduced (step S4).

Each expansion valve is controlled as follows.
First, the second expansion valve 8 has an outlet of the indoor heat exchanger 6 that is obtained by a differential temperature between the saturation temperature of the high-pressure refrigerant detected by the temperature sensor 16h and the outlet temperature of the indoor heat exchanger 6 detected by the temperature sensor 16i. The refrigerant supercooling degree SC is controlled to be a preset target value, for example, 10 ° C.
That is, the refrigerant supercooling degree SC at the outlet of the indoor heat exchanger 6 is compared with the target value (step S5). When the refrigerant supercooling degree SC at the outlet of the indoor heat exchanger 6 is equal to or close to the target value, the opening degree of the second expansion valve 8 is maintained as it is, and the process proceeds to the next step.
When the refrigerant supercooling degree SC at the outlet of the indoor heat exchanger 6 is larger than the target value, the opening degree of the second expansion valve 8 is large, and when the refrigerant subcooling degree SC is smaller than the target value, the second degree. The opening degree of the second expansion valve 8 is changed so that the opening degree of the expansion valve 8 is controlled to be small (step S6).

Next, the first expansion valve 11 has the refrigerant 3 superheated by the compressor 3 detected by the temperature difference between the compressor 3 intake temperature detected by the temperature sensor 16f and the saturation temperature of the low-pressure refrigerant detected by the temperature sensor 16c. The degree SH is controlled to be a preset target value, for example, 10 ° C.
That is, the refrigerant superheating degree SH sucked in the compressor 3 is compared with the target value (step S7). When the refrigerant superheat degree SH sucked into the compressor 3 is equal to or close to the target value, the opening degree of the first expansion valve 11 is maintained as it is, and the process proceeds to the next step.
Further, when the refrigerant superheat degree SH sucked by the compressor 3 is larger than the target value, the opening degree of the first expansion valve 11 is large, and when the refrigerant superheat degree SH is smaller than the target value, the first expansion valve 11 The opening degree of the first expansion valve 11 is changed so that the opening degree is reduced (step S8).

Further, the third expansion valve 14 is controlled so that the discharge temperature of the compressor 3 detected by the temperature sensor 16a becomes a preset target value, for example, 90 ° C.
That is, the discharge temperature of the compressor 3 is compared with the target value (step S9). When the discharge temperature of the compressor 3 is equal to or close to the target value, the opening degree of the third expansion valve 14 is maintained as it is, and the process returns to step S2.
The refrigerant state change when the opening degree of the third expansion valve 14 is changed is as follows.
When the opening degree of the third expansion valve 14 increases, the flow rate of the refrigerant flowing through the injection circuit 13 increases. Since the amount of heat exchange in the second internal heat exchanger 10 does not change greatly depending on the flow rate of the injection circuit 13, if the flow rate of the refrigerant flowing through the injection circuit 13 increases, the heat exchange amount on the injection circuit 13 side of the second internal heat exchanger 10 is increased. The refrigerant enthalpy difference (difference between points 9 and 10 in FIG. 2) decreases, and the injected refrigerant enthalpy (point 10 in FIG. 2) decreases.

Therefore, the enthalpy of the refrigerant enthalpy (point 12 in FIG. 2) after the injected refrigerant merges also decreases. As a result, the discharge enthalpy (point 1 in FIG. 2) of the compressor 3 also decreases, and the discharge temperature of the compressor 3 becomes descend.
Conversely, when the opening of the third expansion valve 14 decreases, the discharge enthalpy of the compressor 3 rises and the discharge temperature of the compressor 3 rises. Therefore, the opening degree control of the third expansion valve 14 controls the opening degree of the third expansion valve 14 to be large when the discharge temperature of the compressor 3 is higher than the target value, and conversely the discharge temperature is lower than the target value. In this case, the opening degree of the third expansion valve 14 is changed such that the opening degree of the third expansion valve 14 is controlled to be small (step S10), and thereafter, the process returns to step S2.

Next, the control operation during the cooling operation will be described based on the flowchart of FIG.
During the cooling operation, first, the capacity of the compressor 3, the opening of the first expansion valve 11, the opening of the second expansion valve 8, and the opening of the third expansion valve 14 are set to initial values (step S11).
Thereafter, when a predetermined time elapses (step S12), each actuator corresponding to the operating state is controlled as follows.

First, the capacity of the compressor 3 is basically controlled such that the air temperature measured by the temperature sensor 16j of the indoor unit 2 becomes a temperature set by the user of the refrigeration air conditioner.
That is, the air temperature of the indoor unit 2 is compared with the set temperature (step S13). When the air temperature is equal to or close to the set temperature, the capacity of the compressor 3 is maintained as it is, and the process proceeds to the next step.
When the air temperature is higher than the set temperature, the capacity of the compressor 3 is increased. When the air temperature is lower than the set temperature, the capacity of the compressor 3 is decreased. 3 is changed (step S14).

Each expansion valve is controlled as follows.
First, the first expansion valve 11 has an outdoor heat exchanger 12 outlet that is obtained by the difference between the saturation temperature of the high-pressure refrigerant detected by the temperature sensor 16c and the outlet temperature of the outdoor heat exchanger 12 detected by the temperature sensor 16d. The refrigerant supercooling degree SC is controlled to be a preset target value, for example, 10 ° C.
That is, the refrigerant supercooling degree SC at the outlet of the outdoor heat exchanger 12 is compared with the target value (step S15). When the refrigerant supercooling degree SC at the outlet of the outdoor heat exchanger 12 is equal to or close to the target value, the opening degree of the first expansion valve 11 is maintained as it is, and the process proceeds to the next step.
When the refrigerant supercooling degree SC at the outlet of the outdoor heat exchanger 12 is larger than the target value, the opening degree of the first expansion valve 11 is large, and when the refrigerant supercooling degree SC is smaller than the target value, the first The opening degree of the first expansion valve 11 is changed so that the opening degree of the expansion valve 11 is controlled to be small (step S16).

Next, the second expansion valve 8 is connected to the compressor 3 suction refrigerant detected by the temperature difference between the compressor 3 suction temperature detected by the temperature sensor 16f and the saturation temperature of the low-pressure refrigerant detected by the temperature sensor 16h. The degree SH is controlled to be a preset target value, for example, 10 ° C.
That is, the refrigerant superheating degree SH sucked into the compressor 3 is compared with the target value (step S17). If the refrigerant superheating degree SH sucked into the compressor 3 is equal to or close to the target value, the opening degree of the second expansion valve 8 is maintained as it is, and the process proceeds to the next step.
Further, when the refrigerant superheat degree SH sucked by the compressor 3 is larger than the target value, the opening degree of the second expansion valve 8 is large, and when the refrigerant superheat degree SH is smaller than the target value, the third expansion valve 8 The opening degree of the second expansion valve 8 is changed so that the opening degree is controlled to be small (step S18).

Next, the third expansion valve 14 is controlled so that the discharge temperature of the compressor 3 detected by the temperature sensor 16a becomes a preset target value, for example, 90 ° C.
That is, the discharge temperature of the compressor 3 is compared with the target value (step S19). When the discharge temperature of the compressor 3 is equal to or close to the target value, the opening degree of the third expansion valve 8 is maintained as it is and the process returns to step S12.
Moreover, since the refrigerant | coolant state change when changing the opening degree of the 3rd expansion valve 14 is the same as that at the time of heating operation, when the discharge temperature of the compressor 3 is higher than a target value, the 3rd expansion valve 14's The opening degree of the third expansion valve 14 is changed so that the opening degree is controlled to be large and, conversely, when the discharge temperature is lower than the target value, the opening degree of the third expansion valve 14 is controlled to be small (step S20). Return to step S12.

Next, the circuit configuration of the present embodiment and the operational effects realized by the control will be described. In the configuration of the present apparatus, the same operation can be performed in both the cooling and heating operations, and therefore the heating operation will be particularly described below.
The circuit configuration of this apparatus is a so-called gas injection circuit. That is, the refrigerant is injected into the compressor 3 from among the refrigerant that has been discharged from the indoor heat exchanger 6 serving as a condenser and has been reduced to an intermediate pressure.

In general, the gas-liquid separator often separates the intermediate pressure refrigerant into liquid / gas and is injected, but in this apparatus, as shown in FIG. 6, the heat exchange in the second internal heat exchanger 10 is performed. Thus, the liquid and gas are thermally separated and injected.
By using a gas injection circuit, the following effects can be obtained.
First, by performing gas injection, the refrigerant flow rate discharged from the compressor 3 increases, and the refrigerant flow rate Gdis discharged from the compressor 3 = the refrigerant flow rate Gsuc sucked by the compressor 3 + the injected refrigerant flow rate Ginj Become.
Therefore, since the flow rate of the refrigerant flowing through the heat exchanger serving as a condenser increases, the heating capacity increases in the heating operation.

On the other hand, as shown in FIG. 6 due to heat exchange in the second internal heat exchanger 10, the refrigerant enthalpy flowing into the heat exchanger serving as an evaporator is lowered, and the refrigerant enthalpy difference in the evaporator is increased. Therefore, the cooling capacity increases even during the cooling operation.
In addition, when gas injection is performed, an efficiency improvement effect can be obtained.
The refrigerant flowing into the evaporator is generally a gas-liquid two-phase refrigerant, but the gas refrigerant does not contribute to the cooling capacity. When viewed from the compressor 3, this low-pressure gas refrigerant also works to increase the pressure together with the gas refrigerant evaporated in the evaporator.

When gas injection is performed, some of the gas refrigerant flowing into the evaporator is extracted at an intermediate pressure, injected, boosted from the intermediate pressure to a high pressure, and compressed.
Therefore, with respect to the flow rate of the injected gas refrigerant, compression work for increasing the pressure from a low pressure to an intermediate pressure becomes unnecessary, and the efficiency is improved accordingly. This effect can be obtained in any operation of air conditioning.

Next, the correlation between the gas injection flow rate and the heating capacity will be described.
When the gas injection flow rate is increased, the refrigerant flow rate discharged from the compressor 3 increases as described above, while the discharge temperature of the compressor 3 decreases and the refrigerant temperature flowing into the condenser also decreases.
Looking at the heat exchange performance of the condenser, in general, the higher the temperature distribution in the heat exchanger, the greater the amount of heat exchange. The refrigerant temperature change when the refrigerant temperature at the condenser inlet is different at the same condensation temperature is as shown in FIG. 7, and the temperature distribution of the portion where the refrigerant is in the superheated gas state in the condenser is different.

In the condenser, the heat exchange amount when the refrigerant is in the two-phase state at the condensation temperature occupies a large amount, but the heat exchange amount of the part that is in the superheated gas state is also about 20% to 30% of the total, and the heat exchange amount The impact of is great.
If the injection flow rate is excessively increased and the refrigerant temperature is significantly reduced in the superheated gas portion, the heat exchange performance in the condenser is lowered and the heating capacity is also lowered. The correlation between the gas injection flow rate and the heating capacity is shown in FIG. 8, and there is a gas injection flow rate at which the heating capacity is maximized.

Next, the effect of the 1st internal heat exchanger 9 in this Embodiment is demonstrated.
In the first internal heat exchanger 9, the high-pressure liquid refrigerant exiting the condenser and the suction refrigerant of the compressor 3 are heat-exchanged. Since the high pressure liquid refrigerant is cooled by the first internal heat exchanger 9, the enthalpy of the refrigerant flowing into the evaporator is lowered, so that the refrigerant enthalpy difference in the evaporator is expanded.
Therefore, the cooling capacity increases during the cooling operation.

On the other hand, the refrigerant sucked into the compressor 3 is heated and the suction temperature rises. Along with this, the discharge temperature of the compressor 3 also rises. Further, in the compression process of the compressor 3, even when the same pressure increase is performed, more work is generally required as the high-temperature refrigerant is compressed.
Therefore, the effect on the efficiency due to the provision of the first internal heat exchanger 9 shows both the increase in capacity due to the expansion of the evaporator enthalpy difference and the increase in compression work, and the influence of the increase in capacity due to the expansion of the evaporator enthalpy difference. If it is larger, the operating efficiency of the device increases.

Next, the effect of combining heat exchange by the first internal heat exchanger 9 and gas injection by the injection circuit 13 as in the present embodiment will be described.
When heat exchange is performed by the first internal heat exchanger 9, the intake temperature of the compressor 3 increases. Therefore, in the change in the compressor 3 when the injection is performed, the refrigerant enthalpy (point 11 in FIGS. 2 and 3) increased from the low pressure to the intermediate pressure becomes higher, and after the merged with the injected refrigerant The refrigerant enthalpy (point 12 in FIGS. 2 and 3) also increases.

Therefore, the discharge enthalpy (point 1 in FIGS. 2 and 3) of the compressor 3 is also increased, and the discharge temperature of the compressor 3 is increased. Therefore, FIG. 9 shows a change in the correlation between the gas injection flow rate and the heating capacity with or without heat exchange by the first internal heat exchanger 9.
When there is heat exchange by the first internal heat exchanger 9, since the discharge temperature of the compressor 3 when the same injection amount is performed is increased, the refrigerant temperature at the condenser inlet is also increased, and the condenser heat exchange amount is Increases heating capacity. Therefore, the injection flow rate at which the heating capacity reaches a peak increases, the peak value of the heating capacity itself increases, and more heating capacity can be obtained.

Even when the first internal heat exchanger 9 is not present, the suction superheat degree of the compressor 3 can be increased and the discharge temperature of the compressor 3 can be increased by controlling the opening degree of the first expansion valve 11. .
However, in this case, since the degree of refrigerant superheat at the outlet of the outdoor heat exchanger 12 that becomes the evaporator also increases, the heat exchange efficiency of the outdoor heat exchanger 12 decreases.
When the heat exchange efficiency of the outdoor heat exchanger 12 is lowered, in order to obtain the same heat exchange amount, the evaporation temperature must be lowered, and the operation is performed at a lower pressure.

When the low pressure is lowered, the refrigerant flow rate sucked by the compressor 3 is also reduced. Therefore, when such an operation is performed, the heating capacity is lowered.
In other words, when the first internal heat exchanger 9 is used, the refrigerant state at the outlet of the outdoor heat exchanger 12 serving as an evaporator becomes an appropriate state, and the discharge temperature of the compressor 3 remains in a state with good heat exchange efficiency. Can be increased, a decrease in the low pressure as described above can be avoided, and an increase in heating capacity can be easily realized.

In the circuit configuration of the present embodiment, a part of the high-pressure refrigerant is bypassed and decompressed, and after being superheated and gasified by the second internal heat exchanger 10, the injection is performed.
Therefore, compared to the case of injecting gas separated using a gas-liquid separator as in the conventional example, the refrigerant amount distribution does not change when the injection amount changes according to the control or operating state, etc. Stable operation can be realized.

Although the third expansion valve 14 has been described as being controlled so that the discharge temperature of the compressor 3 becomes the target value, the control target value is set so that the heating capacity is maximized.
As shown in FIG. 9, since there is a discharge temperature that maximizes the heating capacity based on the correlation between the gas injection flow rate, the heating capacity, and the discharge temperature, this discharge temperature is obtained in advance and set to the target value. Note that the target value of the discharge temperature is not necessarily a constant value, and may be changed as needed according to operating conditions and characteristics of equipment such as a condenser.
By performing the discharge temperature control in this way, the gas injection amount can be controlled to be the maximum heating capacity.

The gas injection amount can be controlled not only to maximize the heating capacity but also to maximize the operating efficiency.
When a large amount of heating capacity is required, such as when the refrigeration air conditioner is activated, the maximum capacity is controlled. In such a case, control is performed to maximize efficiency.

There is a correlation as shown in FIG. 10 between the injection flow rate, the heating capacity, and the operation efficiency. Compared to the maximum heating capacity, the injection flow rate is small and the discharge temperature is high when the operation efficiency is maximum.
At the injection flow rate at which the heating capacity is maximized, the discharge temperature is lowered, so that the heat exchange performance of the condenser is lowered, and in order to increase the injection flow rate, the intermediate pressure is lowered and the injection amount is reduced. By increasing the compression work to be compressed, the efficiency is reduced as compared with the case where the operation efficiency is maximized.

Therefore, the discharge temperature target value controlled by the third expansion valve 14 of the injection circuit 13 has not only the target value that maximizes the heating capacity but also the target value that maximizes the operating efficiency, and the operating status, for example, the operating capacity of the compressor 3. If the heating capacity is required according to the indoor unit side air temperature, the target value is set to the maximum heating capacity, and if not, the target value is set to the maximum operating efficiency.
By performing such an operation, it is possible to realize a large amount of heating capacity and to operate a highly efficient apparatus.

Further, the first expansion valve 11 is controlled so that the suction superheat degree of the compressor 3 becomes a target value, but this control can optimize the superheat degree at the outlet of the heat exchanger as an evaporator, and the heat in the evaporator. While ensuring high exchange performance, it can drive | operate so that a refrigerant | coolant enthalpy difference may also be ensured moderately, and a highly efficient driving | operation can be performed.
Although the degree of superheat at the outlet of the evaporator in such an operation varies depending on the characteristics of the heat exchanger, it is about 2 ° C., and since the refrigerant is heated by the first internal heat exchanger 9, the suction of the compressor 3 The target value of the superheat degree becomes higher than this value, and for example, the above-mentioned 10 ° C. is set as the target value.

Therefore, as the control of the first expansion valve 11, the superheat degree at the outlet of the evaporator, and in the case of heating operation, the superheat degree at the outlet of the outdoor heat exchanger 12 obtained by the difference temperature between the temperature sensor 16b and the temperature sensor 16c For example, you may control so that it may become 2 degreeC mentioned above.
However, when directly controlling the degree of superheat at the outlet of the evaporator, if the target value is a low value of about 2 ° C, the evaporator outlet becomes a gas-liquid two-phase state transiently, and the degree of superheat can be detected appropriately. It becomes difficult to control.

  If the suction superheat degree of the compressor 3 is detected, the target value can be set high, and the situation where the superheat degree cannot be detected properly due to the gas-liquid two-phase suction due to the heating in the first internal heat exchanger 9 occurs. Therefore, control can be performed more easily and stable control can be performed.

In addition, the second expansion valve 8 is controlled so that the degree of supercooling at the outlet of the indoor heat exchanger 6 serving as a condenser becomes a target value, and this control ensures high heat exchange performance in the condenser, The operation can be performed so that the refrigerant enthalpy difference is appropriately secured, and a highly efficient operation can be performed.
The degree of supercooling at the outlet of the condenser for such operation varies depending on the characteristics of the heat exchanger, but is generally around 5 to 10 ° C.

In addition, the operation which increased the heating capability can also be performed by setting the target value of a supercooling degree higher than this value, for example, setting to about 10-15 degreeC.
Therefore, the target value of the degree of supercooling is changed according to the operating conditions, and the heating capacity is secured with a higher target value of supercooling when starting up the device, and high efficiency operation is performed with a lower target value of subcooling when the room temperature is stable. You can also do it.

  The refrigerant of the refrigerating and air-conditioning apparatus is not limited to R410A, but is used for other refrigerants, HFC-based refrigerants R134a, R404A, and R407C, natural refrigerants such as CO2, HC-based refrigerants, ammonia, air, and water. be able to. In particular, when CO2 is used as the refrigerant, the first internal heat exchanger 9 and the second internal heat exchanger 10 are used as a configuration of the present apparatus to deal with the disadvantage that the refrigerant enthalpy difference in the evaporator is small and the operation efficiency is low. Since the difference in the enthalpy of the evaporator can be enlarged, the efficiency can be further improved, which is suitable for application of the present apparatus.

In the case of CO 2 , the condensation temperature does not exist, and the temperature of the high-pressure side heat exchanger serving as a radiator decreases with the flow. Therefore, the change in the heat exchange amount in the radiator becomes a certain constant section condensation temperature, and the influence of the inlet temperature becomes larger, unlike an HFC refrigerant that can secure a constant amount of heat exchange.
Therefore, as in the present embodiment, while raising the discharge temperature by a configuration capable of increasing the injection flow rate, HFC system such as from the greater the rate of increase in heating capacity refrigerant, CO 2 refrigerant in this plane the apparatus It is suitable for application.

Further, the arrangement positions of the first internal heat exchanger 9 and the second internal heat exchanger 10 are not limited to the configuration of FIG. 1, and the same effect can be obtained even if the upstream and downstream positional relationships are opposite. . Further, the position where the injection circuit 13 is taken out is not limited to the position shown in FIG. 1, and the same effect can be obtained as long as the position can be taken out from the other intermediate pressure part and the high pressure liquid part.
In consideration of the control stability of the third expansion valve 14, the position where the injection circuit 13 is taken out is preferably a position where the liquid is completely liquid rather than the gas-liquid two-phase state.

In the present embodiment, since the first internal heat exchanger 9, the second internal heat exchanger 10 and the injection circuit 13 are taken out between the first expansion valve 11 and the third expansion valve 8. The operation with the same injection can be performed in any of the cooling and heating operation modes.
Further, the refrigerant saturation temperature is detected by the refrigerant temperature sensor between the condenser and the evaporator. However, a pressure sensor for detecting high and low pressures may be provided, and the measured pressure value may be converted to obtain the saturation temperature. .

Embodiment 2. FIG.
A second embodiment of the present invention is shown in FIG. FIG. 11 is a refrigerant circuit diagram of the refrigerating and air-conditioning apparatus according to Embodiment 2, in which an intermediate pressure receiver 17 is provided in the outdoor unit, and a suction pipe of the compressor 3 passes therethrough.
The refrigerant in the penetrating portion and the refrigerant in the intermediate pressure receiver 17 are configured to exchange heat, and realize the same function as the first internal heat exchanger 9 in the first embodiment.

  Since the operational effects in this embodiment are the same as those in the first embodiment except for the intermediate pressure receiver 17, the description thereof is omitted. In the intermediate pressure receiver 17, the gas-liquid two-phase refrigerant at the outlet of the indoor exchanger 6 flows in during heating operation, and is cooled in the intermediate pressure receiver 17 and flows out as liquid. During the cooling operation, the gas-liquid two-phase refrigerant that has exited the first expansion valve 11 flows in, and is cooled in the intermediate pressure receiver 17 and flows out as liquid.

  The heat exchange in the intermediate pressure receiver 17 is mainly performed by exchanging the gas refrigerant out of the gas-liquid two-phase refrigerant into contact with the suction pipe to be condensed and liquefied. Therefore, the smaller the amount of liquid refrigerant that stays in the intermediate pressure receiver 17, the larger the area where the gas refrigerant and the suction pipe are in contact with each other, and the amount of heat exchange increases. On the contrary, when the amount of liquid refrigerant staying in the intermediate pressure receiver 17 is large, the area where the gas refrigerant and the suction pipe are in contact with each other decreases, and the amount of heat exchange decreases.

By providing the intermediate pressure receiver 17 as described above, the following effects are obtained.
First, since the outlet of the intermediate pressure receiver 17 is liquid, the refrigerant flowing into the third expansion valve 14 during the heating operation is necessarily liquid refrigerant, so that the flow rate characteristic of the third expansion valve 14 is stable and control stability is achieved. Is ensured, and stable device operation can be performed.
In addition, heat exchange in the intermediate pressure receiver 17 stabilizes the pressure of the intermediate pressure receiver 17, stabilizes the inlet pressure of the third expansion valve 14, and stabilizes the flow rate of the refrigerant flowing through the injection circuit 13. is there. For example, when there is a load fluctuation or the like and the high pressure fluctuates, a pressure fluctuation in the intermediate pressure receiver 17 occurs accordingly, but the pressure fluctuation is suppressed by heat exchange in the intermediate pressure receiver 17.

  When the load increases and the high pressure rises, the pressure in the intermediate pressure receiver 17 also rises. At that time, the pressure difference from the low pressure widens and the temperature difference in the heat exchanger in the intermediate pressure receiver 17 also widens, so heat exchange. The amount increases. When the amount of heat exchange increases, the amount of gas refrigerant in the gas-liquid two-phase refrigerant flowing into the intermediate pressure receiver 17 condenses, so that the pressure does not easily increase and the pressure increase of the intermediate pressure receiver 17 is suppressed. .

On the contrary, when the load decreases and the high pressure decreases, the pressure in the intermediate pressure receiver 17 also decreases. At that time, the pressure difference from the low pressure is narrowed, and the temperature difference in the heat exchanger in the intermediate pressure receiver 17 is also narrowed. As a result, the amount of heat exchange decreases. When the amount of heat exchange decreases, the amount of gas refrigerant in the gas-liquid two-phase refrigerant flowing into the intermediate pressure receiver 17 is reduced, so that the pressure is less likely to decrease, and the pressure of the intermediate pressure receiver 17 is suppressed from decreasing. The
As described above, by performing heat exchange in the intermediate pressure receiver 17, a heat exchange amount variation accompanying the operation state variation occurs autonomously, and as a result, the pressure variation in the intermediate pressure receiver 17 is suppressed.

Moreover, there is an effect that the operation of the apparatus itself is stabilized by exchanging heat in the intermediate pressure receiver 17. For example, when the state on the low pressure side fluctuates and the refrigerant superheat degree at the outlet of the outdoor heat exchanger 12 that is an evaporator becomes large, the temperature difference during heat exchange in the intermediate pressure receiver 17 decreases. Since the amount of heat exchange is reduced and the gas refrigerant is less likely to be condensed, the amount of gas refrigerant in the intermediate pressure receiver 17 is increased and the amount of liquid refrigerant is reduced.
The reduced amount of liquid refrigerant moves to the outdoor heat exchanger 12 and the amount of liquid refrigerant in the outdoor heat exchanger 12 increases, so that the refrigerant superheat degree at the outlet of the outdoor heat exchanger 12 is prevented from increasing. Thus, fluctuations in the operation of the apparatus are suppressed.

Conversely, when the state on the low pressure side fluctuates and the degree of refrigerant superheating at the outlet of the outdoor heat exchanger 12 that is an evaporator becomes small, the temperature difference during heat exchange in the intermediate pressure receiver 17 increases. Therefore, the amount of heat exchange increases and the gas refrigerant is easily condensed, so that the amount of gas refrigerant in the intermediate pressure receiver 17 decreases and the amount of liquid refrigerant increases. This amount of liquid refrigerant moves from the outdoor heat exchanger 12, and the amount of liquid refrigerant in the outdoor heat exchanger 12 decreases, so that the degree of refrigerant superheat at the outlet of the outdoor heat exchanger 12 decreases. Is suppressed, and fluctuations in the operation of the apparatus are suppressed.
The effect of suppressing the fluctuation in superheat is also caused by the fact that the heat exchange amount in the intermediate pressure receiver 17 undergoes heat exchange, whereby the heat exchange amount fluctuation accompanying the operation state fluctuation occurs autonomously.

  As described above, the heat exchange in the first internal heat exchanger 9 according to the first embodiment is performed by the intermediate pressure receiver 17, so that even if the apparatus fluctuates, the heat exchange amount fluctuates autonomously. Therefore, the fluctuation can be suppressed and the apparatus can be operated stably.

In addition, although it is the structure which heat-exchanges with the intermediate pressure receiver 17, if it is the structure which heat-exchanges with the refrigerant | coolant in the intermediate pressure receiver 17, what kind of structure will be able to acquire the same effect. For example, a configuration in which the suction pipe of the compressor 3 is brought into contact with the outer periphery of the container of the intermediate pressure receiver 17 to perform heat exchange may be used.
Further, the refrigerant supplied to the injection circuit 13 may be supplied from the bottom of the intermediate pressure receiver 17. In this case, since the liquid refrigerant flows into the third expansion valve 14 in each operation of cooling and heating, the flow rate characteristic of the third expansion valve 14 is stable in both the cooling and heating operations, and control stability is ensured. Is done.

  DESCRIPTION OF SYMBOLS 1 Outdoor unit, 2 Indoor unit, 3 Compressor, 4 Four way valve, 5 Gas pipe, 6 Indoor heat exchanger, 7 Liquid pipe, 8 2nd expansion valve, 9 1st internal heat exchanger, 10 2nd internal heat exchange 11, first expansion valve, 12 outdoor heat exchanger, 13 injection circuit, 14 expansion valve for injection, 15 measurement control device.

Claims (20)

  1. An evaporator (12) that absorbs heat of air into the refrigerant, a compressor (3) that sucks the refrigerant from the evaporator (12), and heat of the refrigerant discharged from the compressor (3) And a first expansion valve (11) for reducing the pressure of the refrigerant flowing from the load side heat exchanger (6) to the evaporator (12) circulates the refrigerant. In the heat pump device that has the main refrigerant circuit connected as described above and uses the heat radiated from the load side heat exchanger (6),
    1st internal heat which gives the heat | fever of the refrigerant | coolant which flows toward the said evaporator (12) from the said load side heat exchanger (6) to the refrigerant | coolant which flows toward the said compressor (3) from the said evaporator (12). An exchanger (9);
    Part of the refrigerant flowing from the load-side heat exchanger (6) toward the evaporator (12) is sucked into the compressor (3) through the evaporator (12) and compressed to an intermediate pressure. A bypass path (13) for joining the refrigerant;
    A third expansion valve (14) provided in the bypass path (13) for reducing the pressure of the refrigerant flowing through the bypass path (13);
    Provided in the main refrigerant circuit and the bypass path (13), the heat of the refrigerant flowing from the load side heat exchanger (6) toward the evaporator (12) is converted into the refrigerant flowing through the bypass path (13). A second internal heat exchanger (10) providing;
    And a control device (15) for controlling the opening degree of the first expansion valve (11) and the third expansion valve (14).
  2. A compressor discharge side temperature sensor (16a) for detecting the discharge temperature of the refrigerant discharged from the compressor (3);
    The control device (15)
    When the refrigerant discharge temperature detected by the compressor discharge-side temperature sensor (16a) is higher than the target value, the opening of the third expansion valve (14) is increased so as to reduce the enthalpy of the refrigerant. 2. The heat pump device according to claim 1, wherein the opening degree of the third expansion valve is controlled to be small so as to increase the enthalpy of the refrigerant when the control value is lower than the target value.
  3. The refrigerant flowing through the bypass path (13) is
    The heat pump device according to claim 1 or 2, wherein a gas-liquid two-phase state is obtained by the third expansion valve (14).
  4. The bypass path (13)
    The heat pump device according to any one of claims 1 to 3, wherein the heat pump device is branched from between the load-side heat exchanger (6) and the first expansion valve (11).
  5. The bypass path (13)
    The heat pump device according to claim 4, wherein the heat pump device is branched from between the first internal heat exchanger (9) and the second internal heat exchanger (10).
  6. The second expansion valve (8) is provided between the load side heat exchanger (6) and the first internal heat exchanger (9). The heat pump apparatus as described.
  7. The heat pump apparatus according to claim 1, wherein the refrigerant is a CO 2 refrigerant.
  8. The heat pump device according to claim 1, wherein the refrigerant is an HC refrigerant.
  9. The heat pump device according to any one of claims 1 to 8, wherein the load side medium that exchanges heat with the refrigerant discharged from the compressor (3) in the load side heat exchanger (6) is air. .
  10. The heat pump device according to any one of claims 1 to 8, wherein the load-side medium that exchanges heat with the refrigerant discharged from the compressor (3) in the load-side heat exchanger (6) is water. .
  11. An evaporator (12) that absorbs heat of air into the refrigerant, and a compressor (3) that sucks the refrigerant from the evaporator (12) and discharges the refrigerant to a load-side heat exchanger (6) provided outside. And a first expansion valve (11) for lowering the pressure of the refrigerant flowing toward the evaporator (12) after applying heat to the load-side medium by the load-side heat exchanger (6) provided outside. In the outdoor unit of the heat pump device that has a main refrigerant circuit connected to circulate the refrigerant and uses heat radiated from the load-side heat exchanger (6),
    1st internal heat which gives the heat | fever of the refrigerant | coolant which flows toward the said evaporator (12) from the said load side heat exchanger (6) to the refrigerant | coolant which flows toward the said compressor (3) from the said evaporator (12). An exchanger (9);
    Part of the refrigerant flowing from the load-side heat exchanger (6) toward the evaporator (12) is sucked into the compressor (3) through the evaporator (12) and compressed to an intermediate pressure. A bypass path (13) for joining the refrigerant;
    A third expansion valve (14) provided in the bypass path (13) for reducing the pressure of the refrigerant flowing through the bypass path (13);
    Provided in the main refrigerant circuit and the bypass path (13), the heat of the refrigerant flowing from the load side heat exchanger (6) toward the evaporator (12) is converted into the refrigerant flowing through the bypass path (13). A second internal heat exchanger (10) providing;
    A control device (15) for controlling the opening degree of the first expansion valve (11) and the third expansion valve (14).
    And an outdoor unit of a heat pump device.
  12. A compressor discharge side temperature sensor (16a) for detecting the discharge temperature of the refrigerant discharged from the compressor (3);
    The control device (15)
    When the refrigerant discharge temperature detected by the compressor discharge-side temperature sensor (16a) is higher than the target value, the opening of the third expansion valve (14) is increased so as to reduce the enthalpy of the refrigerant. The outdoor unit of the heat pump device according to claim 11, wherein the opening degree of the third expansion valve (14) is controlled to be small so as to increase the enthalpy of the refrigerant when the control value is lower than the target value. .
  13. The refrigerant flowing through the bypass path (13) is
    The outdoor unit of the heat pump device according to claim 11 or 12, wherein the third phase expansion valve (14) is in a gas-liquid two-phase state.
  14. The bypass path (13)
    The outdoor unit of the heat pump apparatus according to any one of claims 11 to 13, wherein the outdoor unit branches from between the load-side heat exchanger (6) and the first expansion valve (11).
  15. The bypass path (13)
    The outdoor unit of the heat pump device according to claim 14, wherein the outdoor unit is branched from between the first internal heat exchanger (9) and the second internal heat exchanger (10).
  16. The second expansion valve (8) is provided between the load side heat exchanger (6) and the first internal heat exchanger (9). The outdoor unit of the heat pump apparatus described.
  17. The refrigerant, the outdoor unit of the heat pump apparatus according to any one of claims 11 to 16, characterized in that a CO 2 refrigerant.
  18. The outdoor unit of a heat pump device according to any one of claims 11 to 16, wherein the refrigerant is an HC refrigerant.
  19. The heat pump device according to any one of claims 11 to 18, wherein the load-side medium that exchanges heat with the refrigerant discharged from the compressor (3) in the load-side heat exchanger (6) is air. Outdoor unit.
  20. The heat pump device according to any one of claims 11 to 18, wherein the load-side medium that exchanges heat with the refrigerant discharged from the compressor (3) in the load-side heat exchanger (6) is water. Outdoor unit.
JP2010096148A 2010-04-19 2010-04-19 Heat pump device and outdoor unit for the heat pump device Pending JP2010159967A (en)

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WO2013121844A1 (en) * 2012-02-15 2013-08-22 サンデン株式会社 Vehicle air-conditioning device
JP2013189179A (en) * 2012-02-15 2013-09-26 Sanden Corp Vehicle air conditioner

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