JP2009270785A - Refrigerating cycle device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a refrigerating cycle device of high reliability for performing a stable operation regardless of an operating state, having high efficiency improving effect by an ejector, and coping with clogging and the like caused by aged deterioration. <P>SOLUTION: This refrigerating cycle device includes a refrigerant circuit comprising a compressor 3, a four-way valve 4, an outdoor heat exchanger 11, a first expansion valve 10, a first internal heat exchanger 14, a second expansion valve 8, an indoor heat exchanger 6 and the ejector 12, and a refrigerant circuit in which they are circularly connected corresponding to a heating operation or a cooling operation by the four-way valve 4 is provided. Further a first branch pathway 16 is branched from between the indoor heat exchanger 6 and the second expansion valve 8 in the heating operation to circulate a refrigerant to a driving nozzle 12a of the ejector 12, and a second branch pathway 17 is branched from between the outdoor heat exchanger 11 and the first expansion valve 10 in the cooling operation to circulate the refrigerant to a driving nozzle a of the ejector 12. The first internal heat exchanger 14 exchange heat between the refrigerant flowing from a diffuser 14d of the ejector to a suction port of the compressor 3, and the refrigerant flowing between the first expansion valve 10 and the second expansion valve 8. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a refrigeration cycle apparatus, and more particularly to a refrigeration cycle apparatus in which an ejector is incorporated to reduce expansion loss.

  As a conventional refrigeration cycle device, for example, “a compressor, a condenser, a supercooling heat exchanger, an expansion device, an evaporator, and an ejector are sequentially connected, and one end is connected between the condenser and the expansion device pipe, Provided with a bypass passage whose end is connected to the inlet side of the ejector drive nozzle of the ejector, the outlet side of the evaporator is connected to the suction part of the ejector, and the outlet side of the diffuser is connected to the compressor via the supercooling heat exchanger The refrigerant of the supercooling heat exchanger is cooled by the refrigerant in the bypass passage, ”(for example, see Patent Document 1).

JP 2007-78318 A (summary, FIG. 1)

However, the conventional refrigeration cycle apparatus has the following problems.
First, in the refrigeration cycle apparatus in which the ejector is incorporated as in the conventional example of Patent Document 1 described above, the efficiency improvement effect by the ejector varies depending on the arrangement method of each component, and thus it is necessary to consider. In addition, when an electronic expansion valve is used as the pressure reducing means, the flow rate characteristic also changes depending on the refrigerant state at the inlet, and therefore it is necessary to consider the inlet refrigerant state from the viewpoint of the stability of the refrigeration cycle.

  In view of the above problems, the present invention provides a highly reliable refrigeration cycle apparatus that is capable of stable operation regardless of the operation state, has a high efficiency improvement effect by the ejector, and also supports clogging due to aging. The purpose is to obtain.

  A refrigeration cycle apparatus according to the present invention includes a compressor, a flow path switching unit, a heat source side heat exchanger, a first pressure reducing device, a first internal heat exchanger, a second pressure reducing device, a use side heat exchanger, and an ejector. These are refrigeration cycle devices including a refrigerant circuit that is connected in a predetermined cyclic manner in response to heating operation or cooling operation by switching by the flow path switching means, and during the heating operation, the use side heat A first branch passage that branches off from between the exchanger and the second decompression device and through which refrigerant flows to the drive nozzle of the ejector; and the heat source side heat exchanger and the first decompression device during cooling operation And a second branch passage through which the refrigerant flows to the drive nozzle of the ejector, wherein the first internal heat exchanger is a refrigerant that flows from the booster of the ejector to the suction port of the compressor And the first decompressor And a refrigerant flowing between the serial second decompressor is to heat exchange.

  The refrigeration cycle apparatus according to the present invention includes the first branch path and the second branch path as described above, and the first internal heat exchanger flows from the booster of the ejector to the suction port of the compressor. Heat is exchanged between the refrigerant and the refrigerant flowing between the first decompression device and the second decompression device. For this reason, the operation conditions and the operation state of the heat source side heat exchanger or the use side heat exchanger are exchanged. Regardless of this, an expansion loss in the refrigeration cycle can be reduced, efficiency can be improved, and a highly reliable refrigeration cycle apparatus capable of continuing operation against clogging due to foreign matter due to deterioration over time can be provided.

Embodiment 1 FIG.
Embodiment 1 of the present invention will be described below.
FIG. 1 is a refrigerant circuit diagram of the refrigeration cycle apparatus according to the first embodiment. As shown in FIG. 1, the refrigeration cycle apparatus includes an outdoor unit 1 and an indoor unit 2. In the outdoor unit 1, there are a compressor 3, a four-way valve 4, an outdoor heat exchanger 11 that is a heat source side heat exchanger, a first expansion valve 10 that is a first pressure reducing device, a first internal heat exchanger 14, A second expansion valve 8, which is a decompression device 2, an ejector 12, an electromagnetic valve 13 that opens and closes a bypass circuit that circulates on the inlet side of the drive nozzle 12a of the ejector 12, and a check valve 15 that restricts the flow of refrigerant in one direction. It is installed. The compressor 3 is of a type in which the number of revolutions is controlled by an inverter, for example, and the capacity is controlled. The first expansion valve 10 and the second expansion valve 8 are electronic expansion valves whose opening degree is variably controlled. The outdoor heat exchanger 11 exchanges heat with the outside air blown by a fan (not shown) or the like. The ejector 12 includes a drive nozzle 12a, a suction unit (low pressure refrigerant suction port) 12b, a mixing unit 12c, and a diffuser (pressure increase unit) 12d.

  Inside the indoor unit 2, an indoor heat exchanger 6 that is a use side heat exchanger is mounted. The gas pipe 5 and the liquid pipe 7 are connection pipes that connect the outdoor unit 1 and the indoor unit 2. In addition, the arrow in a figure shows the flow of a refrigerant | coolant. As the refrigerant of the refrigeration cycle apparatus, for example, R410A, which is an HFC mixed refrigerant, is used.

  In the outdoor unit 1, a first branch 16 that branches from between the indoor heat exchanger 6 and the second expansion valve 8 and a second branch that branches from between the outdoor heat exchanger 11 and the first expansion valve 10. 17 is provided, and the first branch path 16 and the second branch path 17 are joined on the way and then connected to the drive nozzle 12a inlet side of the ejector 12 via the electromagnetic valve 13. A check valve 15 is provided in each of the first branch path 16 and the second branch path 17, so that the flow of the refrigerant is in one direction toward the drive nozzle 12 a of the ejector 12. Further, refrigerant flowing through the four-way valve 4 from the evaporator (cooling: indoor heat exchanger 6, heating: outdoor heat exchanger 11) is supplied to the suction part 12b of the ejector 12, and the outlet side of the diffuser 12d of the ejector 12 is It is connected to the suction side of the compressor 3 via the first internal heat exchanger 14.

  In the outdoor unit 1, a measurement control device 22 and temperature sensors 18a, 18b, 18c, 18d, 18e, and 18f are installed. The temperature sensor 18a is on the discharge side of the compressor 3, the temperature sensor 18b is on the suction side of the compressor 3, the temperature sensor 18c is on the refrigerant flow path in the middle of the outdoor heat exchanger 11, and the temperature sensor 18d is on the outdoor heat exchanger 11 and the first expansion valve. 10, the temperature sensor 18e is provided between the outlet side of the diffuser 12d of the ejector 12 and the first internal heat exchanger 14, and measures the refrigerant temperature at the installation location. The temperature sensor 18f measures the outside air temperature around the outdoor unit 1.

  In the indoor unit 2, temperature sensors 18g, 18h, and 18i are installed. The temperature sensor 18g is on the refrigerant flow path in the middle of the indoor heat exchanger 6, and the temperature sensor 18h is the indoor heat exchanger 6 and the liquid pipe 7. The temperature of the refrigerant at each installation location is measured. The temperature sensor 18 i measures the temperature of the 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 18i measures the inflow temperature of the medium.

  The temperature sensors 18c and 18g can detect the high and low pressure refrigerant saturation temperature by detecting the refrigerant temperature in the gas-liquid two-phase state in the middle of the heat exchanger. In the following description, the temperature sensors 18a to 18i are collectively referred to as the temperature sensor 18.

  The measurement control device 22 is configured by a microcomputer or the like, and takes in measurement information of the temperature sensor 18 in the outdoor unit 1 and the indoor unit 2 and operation information instructed by a refrigeration cycle apparatus user. Based on the information, the operation method of the compressor 3, the flow path switching of the four-way valve 4, the fan air flow rate of the outdoor heat exchanger 11, the opening degree of each expansion valve 8, 9 are controlled.

Next, the operation of the refrigeration cycle apparatus will be described.
FIG. 2 is a Ph diagram showing the operating state of the refrigeration cycle apparatus of FIG. 1, and the operation will be described with reference to the refrigerant circuit of FIG. 1 and the Ph diagram of FIG.
First, a heating operation will be described as an example of the operation state.
During the heating operation, the flow path of the four-way valve 4 is set in the direction of the solid line in FIG. 1, and the compressor 3, the four-way valve 4, the indoor heat exchanger 6, the second expansion valve 8, the first internal heat exchanger 14, and the first A refrigerant circuit is formed in which the expansion valve 10, the outdoor heat exchanger 11, the four-way valve 4, and the ejector 12 (suction unit 12b-diffuser 12d) are connected in an annular shape.
During the heating operation, the high-temperature and high-pressure gas refrigerant (point 1 in FIG. 2) discharged from the compressor 3 flows into the indoor heat exchanger 6 acting as a condenser, where it condenses and liquefies while dissipating heat. It becomes a refrigerant (point 2 in FIG. 2). After the refrigerant exiting the indoor heat exchanger 6 is depressurized by the second expansion valve 8 (point 3 in FIG. 2), it flows into the first internal heat exchanger 14 and is cooled by exchanging heat with the low-pressure refrigerant (FIG. 2). 2 point 4), after being depressurized by the first expansion valve 10 (FIG. 2 point 5), it flows to the outdoor heat exchanger 11 acting as an evaporator and reaches its outlet (point 6 in FIG. 2).

  On the other hand, a part of the refrigerant (point 2 in FIG. 2) exiting the indoor heat exchanger 6 is driven from the first branch passage 16 through the electromagnetic valve 13 before being decompressed by the second expansion valve 8, and the drive nozzle of the ejector 12 The refrigerant flows into the inlet side of 12a and is decompressed at a speed (point 7 in FIG. 2), and flows out from the outdoor heat exchanger 11 and sucks the refrigerant (point 6 in FIG. 2) guided to the suction part 12b of the ejector 12. The refrigerant flowing out from the drive nozzle 12a of the ejector 12 and the refrigerant sucked from the suction part 12b of the ejector 12 are mixed by the mixing part 12c of the ejector 12 (point 8 in FIG. 2), and the pressure is increased by the diffuser 12d of the ejector 12 ( FIG. 2 point 9). Thereafter, after being heated and vaporized by the internal heat exchanger 14 (point 10 in FIG. 2), the process returns to the suction of the compressor 3.

Next, the operation of the refrigeration cycle apparatus during the cooling operation will be described. Note that the Ph diagram representing the operating state of the cooling operation is substantially the same as that in the heating operation, and the same operation can be realized in either operation mode, and thus will be described with reference to FIG.
During the cooling operation, the flow path of the four-way valve 4 is set in the direction of the wavy line in FIG. 1, and the compressor 3, the four-way valve 4, the outdoor heat exchanger 11, the first expansion valve 10, the first internal heat exchanger 14, the first A refrigerant circuit is formed in which the two expansion valve 8, the indoor heat exchanger 6, the four-way valve 4, and the ejector 12 (suction part 12b-diffuser 12d) are connected in an annular shape.
During the cooling operation, the high-temperature and high-pressure gas refrigerant (point 1 in FIG. 2) discharged from the compressor 3 flows into the outdoor heat exchanger 11 acting as a condenser, where it condenses and liquefies while dissipating heat, and the high-pressure and low-temperature refrigerant. (Point 2 in FIG. 2). After the refrigerant exiting the outdoor heat exchanger 11 is depressurized by the first expansion valve 10 (point 3 in FIG. 2), it flows to the internal heat exchanger 14 and is cooled by exchanging heat with the low-pressure refrigerant (point in FIG. 2). 4) After being depressurized by the second expansion valve 8 (point 5 in FIG. 2), it flows into the indoor heat exchanger 6 acting as an evaporator and reaches its outlet (point 6 in FIG. 2).

  On the other hand, a part of the refrigerant (point 2 in FIG. 2) exiting the outdoor heat exchanger 11 enters the drive nozzle 12a of the ejector 12 through the electromagnetic valve 13 from the second branch path 17 before flowing into the first expansion valve 10. Then, the refrigerant is decompressed by obtaining a speed (point 7 in FIG. 2), and the refrigerant (point 6 in FIG. 2) flowing out from the indoor heat exchanger 6 and guided to the suction part 12b of the ejector 12 is sucked. The refrigerant flowing out from the drive nozzle 12a of the ejector 12 and the refrigerant sucked from the suction part 12b of the ejector 12 are mixed by the mixing part 12c of the ejector 12 (point 8 in FIG. 2), and the pressure is increased by the diffuser 12d of the ejector 12 ( FIG. 2 point 9). Then, after being heated and vaporized by the first internal heat exchanger 14 (point 10 in FIG. 2), the process returns to the suction of the compressor 3.

Next, the operation control operation of this refrigeration cycle apparatus will be described.
First, the control operation during the heating operation will be described.
During the heating operation, the capacity of the compressor 3, the opening of the first expansion valve 10, and the opening of the second expansion valve 8 are set to initial values. Thereafter, each actuator according to the operating state is controlled as follows.
The capacity of the compressor 3 is basically controlled so that the air temperature measured by the temperature sensor 18 i of the indoor unit 2 becomes a temperature set by the user of the refrigeration air conditioner. Therefore, 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. When the air temperature becomes higher than the set temperature, the capacity of the compressor 3 is reduced. In a so-called low compression ratio operation state where the difference between the high pressure and the low pressure is small at the time of startup or the like, the electromagnetic valve 13 is closed because the power recovery effect at the ejector 12 is not sufficiently obtained, and the condensation detected by the temperature sensor 18g. The difference between the condensation pressure obtained using the temperature as the saturation temperature and the evaporation pressure obtained using the evaporation temperature detected by the temperature sensor 18c as the saturation temperature is sufficiently large, and it is determined that the power recovery effect in the ejector 12 can be obtained. In that case, the solenoid valve 13 is opened, and the refrigerant is allowed to flow to the drive nozzle 12a inlet side of the ejector 12.

The control of each expansion valve 8, 10 is performed as follows.
First, the second expansion valve 8 is provided at the outlet of the indoor heat exchanger 6 obtained by the difference between the saturation temperature of the high-pressure refrigerant detected by the temperature sensor 18g and the outlet temperature of the indoor heat exchanger 6 detected by the temperature sensor 18h. The refrigerant supercooling degree SC is controlled to be a preset target value, for example, 5 ° C. When the refrigerant supercooling degree SC 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 opening degree of the second expansion valve 8 is controlled to be small. Is done.

  Next, the first expansion valve 10 has the refrigerant 3 superheated by the compressor 3 detected by the temperature difference between the compressor 3 suction temperature detected by the temperature sensor 18b and the saturation temperature of the low-pressure refrigerant detected by the temperature sensor 18e. The degree SH is controlled to be a preset target value, for example, 5 ° C. When the refrigerant superheat degree SH is larger than the target value, the opening degree of the first expansion valve 10 is large, and when the refrigerant superheat degree SH is smaller than the target value, the opening degree of the first expansion valve 10 is controlled to be small. .

Next, the control operation during the cooling operation will be described.
During the cooling operation, first, the capacity of the compressor 3, the opening of the first expansion valve 10, and the opening of the second expansion valve 8 are set to initial values. Thereafter, each actuator according to the operating state is controlled as follows.
The capacity of the compressor 3 is basically controlled so that the air temperature measured by the temperature sensor 18 i of the indoor unit 2 becomes a temperature set by the user of the refrigeration air conditioner. Therefore, when the air temperature is higher 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. When the air temperature becomes lower than the set temperature, the capacity of the compressor 3 is reduced. The control of the solenoid valve 13 is the same as in the heating operation, and the temperature sensor 18c is used for detecting the condensation temperature and the temperature sensor 18g is used for detecting the evaporation temperature during the cooling operation.

The expansion valves 10 and 8 are controlled as follows.
First, the first expansion valve 10 is provided at the outlet of the outdoor heat exchanger 11 obtained by the difference between the saturation temperature of the high-pressure refrigerant detected by the temperature sensor 18c and the outlet temperature of the outdoor heat exchanger 11 detected by the temperature sensor 18d. The refrigerant supercooling degree SC is controlled to be a preset target value, for example, 5 ° C. When the refrigerant supercooling degree SC is larger than the target value, the opening degree of the first expansion valve 10 is large, and when the refrigerant subcooling degree SC is smaller than the target value, the opening degree of the first expansion valve 10 is controlled to be small. Is done.

  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 18b and the saturation temperature of the low-pressure refrigerant detected by the temperature sensor 18e. The degree SH is controlled to be a preset target value, for example, 5 ° C. When the refrigerant superheat degree SH 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 opening degree of the second expansion valve 8 is controlled to be small. .

Next, functions and effects realized by the circuit configuration and control of the present embodiment will be described. Note that, in the configuration of the refrigeration cycle apparatus according to the present embodiment, the same operation can be performed in both the cooling and heating operations, and therefore the heating operation will be particularly described below.
In the refrigeration cycle apparatus according to the present embodiment, the refrigerant boosted by the ejector 12 is sucked into the compressor 3, so that the amount of compression work in the compressor 3 is reduced compared to a normal circuit, and the refrigeration cycle has high efficiency. Can be achieved. In order to further enhance the efficiency improvement effect of the refrigeration cycle by the ejector 12, it is necessary to increase the amount of pressure increase in the diffuser 12d of the ejector 12, and for that purpose, it is necessary to increase the amount of expansion power recovered from the drive nozzle 12a of the ejector 12 There is. For this purpose, it is better to make the enthalpy of the refrigerant flowing into the drive nozzle 12a inlet side of the ejector 12 as high as possible, and for that purpose, it is better to make the refrigerant subcooling degree SC at the outlet of the indoor heat exchanger 6 as small as possible. Further, it is preferable that the amount of pressure reduction at the drive nozzle 12a of the ejector 12 is large, and for that purpose, the pressure of the refrigerant at the inlet side of the drive nozzle 12a of the ejector 12 is preferably high.

  On the other hand, in order to increase the amount of heat exchange in the evaporator (heating: outdoor heat exchanger 11), it is better to reduce the refrigerant enthalpy at the inlet of the evaporator as much as possible. For this purpose, the refrigerant at the outlet of the indoor heat exchanger 6 is preferred. Although it is necessary to increase the degree of supercooling SC, this is a contradictory condition for obtaining the efficiency improvement effect of the ejector 12 as described above.

  Therefore, by adopting the configuration as in the present embodiment, first, the second expansion valve 8 controls the refrigerant supercooling degree SC at the outlet of the indoor heat exchanger 6 to be appropriately small, and the electromagnetic valve 13 is opened to open the ejector 12. The enthalpy of the refrigerant flowing in at the inlet side of the drive nozzle 12a can be kept as high as possible and the pressure can be kept high. Then, the refrigerant | coolant enthalpy at the entrance of the outdoor heat exchanger 11 can be reduced by exchanging heat with the low-pressure refrigerant in the first internal heat exchanger 14 to increase the degree of supercooling. Further, the flow rate of the refrigerant flowing to the outdoor heat exchanger 11 is appropriately controlled by the first expansion valve 10, and the two-phase refrigerant after flowing out of the diffuser 12d of the ejector 12 is heat-exchanged via the first internal heat exchanger 14 to be vaporized. After that, the liquid back to the compressor 3 can be prevented by returning to the suction of the compressor 3. Thus, a highly reliable refrigeration cycle can be obtained while enhancing the efficiency improvement effect of the ejector 12.

  In addition, according to the present embodiment as described above, by having the two expansion valves (decompression means) 8 and 10, the same efficiency improvement effect can be obtained in both the cooling operation and the heating operation. Therefore, the effect of improving the refrigeration cycle efficiency by the ejector 12 can be enhanced regardless of the operating state.

  Furthermore, only a part of the refrigerant flow is caused to flow through the drive nozzle 12a of the ejector 12, so that sludge generated due to aging deterioration or deterioration of the refrigeration oil for lubrication of the compressor 3 due to overheating operation causes the drive nozzle 12a of the ejector 12 to drive. Even when the clogging occurs in the throat where the flow path is narrowest, the operation of the refrigeration cycle apparatus can be continued, so that the reliability of the refrigeration cycle apparatus equipped with an ejector against aging can be improved.

Embodiment 2. FIG.
A second embodiment of the present invention is shown in FIG.
FIG. 3 is a refrigerant circuit diagram of the refrigeration cycle apparatus according to the second embodiment. Instead of the first internal heat exchanger 14 of the first embodiment, an intermediate pressure receiver (hereinafter, referred to as an intermediate pressure receiver) 9 with an internal heat exchange function is provided in the outdoor unit 1, and the compressor 3 is provided therein. The suction pipe penetrates. The refrigerant in the penetrating portion and the refrigerant in the intermediate pressure receiver 9 are configured to exchange heat, and realize the same function as the first internal heat exchanger 14 (FIG. 1) of the first embodiment. Yes. For this reason, FIG. 4 which is a Ph diagram representing the driving situation of the second embodiment has the same characteristics as FIG. 2 which is the Ph diagram of the first embodiment.

Since the operational effects in the present embodiment are the same as those in the first embodiment except for the intermediate pressure receiver 9, the description thereof is omitted.
In the intermediate pressure receiver 9, the gas-liquid two-phase refrigerant at the outlet of the second expansion valve 8 flows in during the heating operation, and is cooled in the intermediate pressure receiver 9 and flows out as liquid. During the cooling operation, the gas-liquid two-phase refrigerant that has exited the first expansion valve 10 flows in, cools in the intermediate pressure receiver 9, and flows out as liquid. The heat exchange in the intermediate pressure receiver 9 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 staying in the intermediate pressure receiver 9, the more 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 9 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 such a medium pressure receiver 9 in the refrigerant circuit, the following effects can be obtained.
First, since the refrigerant at the outlet of the intermediate pressure receiver 9 is liquid, the refrigerant flowing into the first expansion valve 10 during the heating operation is necessarily liquid refrigerant, so that the flow rate characteristic of the first expansion valve 10 is stable and the control is stable. Performance is ensured, and stable device operation can be performed.

Further, the heat exchange in the intermediate pressure receiver 9 has an effect that the operation of the apparatus itself is stabilized. For example, when the state on the low pressure side fluctuates and the refrigerant superheat degree at the outlet of the outdoor heat exchanger 11 as an evaporator increases, the temperature difference during heat exchange in the intermediate pressure receiver 9 decreases. Since the amount of heat exchange decreases and the gas refrigerant is less likely to be condensed, the amount of gas refrigerant in the intermediate pressure receiver 9 increases and the amount of liquid refrigerant decreases. The reduced amount of liquid refrigerant moves to the outdoor heat exchanger 11 and the amount of liquid refrigerant in the outdoor heat exchanger 11 increases, so that the refrigerant superheat degree at the outlet of the outdoor heat exchanger 11 is prevented from increasing. Thus, fluctuations in the operation of the apparatus are suppressed. On the other hand, when the state on the low pressure side fluctuates and the refrigerant superheat degree at the outlet of the outdoor heat exchanger 11 as an evaporator becomes small, the temperature difference during heat exchange in the intermediate pressure receiver 9 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 9 decreases and the amount of liquid refrigerant increases. This amount of liquid refrigerant moves from the outdoor heat exchanger 11, and the amount of liquid refrigerant in the outdoor heat exchanger 11 decreases, so that the degree of refrigerant superheat at the outlet of the outdoor heat exchanger 11 decreases. Is suppressed, and fluctuations in the operation of the apparatus are suppressed.
The action of suppressing the fluctuation in superheat degree is also caused by the fact that the heat exchange amount fluctuation accompanying the fluctuation of the operation state is autonomously generated by performing heat exchange in the intermediate pressure receiver 9.

  As described above, the heat exchange in the internal heat exchanger 14 of the first embodiment is performed by the intermediate pressure receiver 9 in the second embodiment, so that even if the operation fluctuation of the apparatus occurs, Since the fluctuation can be suppressed by the autonomous fluctuation of heat exchange amount and the apparatus can be operated stably, the effect of improving the refrigeration cycle efficiency by the ejector 12 can be stably exhibited regardless of the operation state. .

Embodiment 3 FIG.
A third embodiment of the present invention is shown in FIG.
FIG. 5 is a refrigerant circuit diagram of the refrigeration cycle apparatus according to Embodiment 3. The refrigeration cycle apparatus of the present embodiment includes an injection circuit 21 that partially bypasses the refrigerant between the first expansion valve 10 and the second expansion valve 8 and injects the refrigerant into the compression chamber in the compressor 3. The third expansion valve 19 that is the third decompression device, and the second refrigerant that exchanges heat between the refrigerant decompressed by the third expansion valve 19 and the refrigerant between the first expansion valve 10 and the second expansion valve 8. The point provided with the internal heat exchanger 20 is different from the first embodiment.

Next, the operation of the refrigeration cycle apparatus will be described.
First, the operation during heating operation will be described.
FIG. 6 is a Ph diagram showing the operating condition of the refrigeration cycle apparatus of FIG. 5 during heating operation, and the operation will be described with reference to the refrigerant circuit of FIG. 5 and the Ph diagram of FIG. To do.
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. 6) 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 radiating heat in the indoor heat exchanger 6 acting as a condenser to become a high-pressure and low-temperature liquid refrigerant (point 2 in FIG. 6), and the heat radiated from the refrigerant is transferred to the load side. Heating is performed by giving it to a load-side medium such as air or water. After the high-pressure and low-temperature refrigerant exiting the indoor heat exchanger 6 flows into the outdoor unit 1 via the liquid pipe 7, a part of the refrigerant branches off at the first branch passage 16 and then passes through the second expansion valve 8. The pressure is slightly reduced (point 3 in FIG. 6), and the first internal heat exchanger 14 heats and cools the low-temperature refrigerant sucked by the compressor 3 (point 4 in FIG. 6). Then, after partially bypassing the refrigerant to the injection circuit 21, the second internal heat exchanger 20 bypasses the injection circuit 21 and exchanges heat with the refrigerant that has been depressurized by the third expansion valve 19 to a low temperature. It is cooled (point 5 in FIG. 6). Thereafter, the refrigerant is depressurized to a low pressure by the first expansion valve 10 to become a two-phase refrigerant (point 6 in FIG. 6), and then flows into the outdoor heat exchanger 11 acting as an evaporator, where it absorbs heat and evaporates to be gasified. (Point 7 in FIG. 6).

  On the other hand, a part of the refrigerant (point 2 in FIG. 6) flowing into the outdoor unit 1 enters the drive nozzle 12a of the ejector 12 from the first branch passage 16 through the electromagnetic valve 13 before being depressurized by the second expansion valve 8. The refrigerant flows into the side, gains speed and is depressurized (point 8 in FIG. 6), and flows out from the outdoor heat exchanger 11 and sucks the refrigerant (point 7 in FIG. 6) guided to the suction part 12b of the ejector 12. The refrigerant flowing out from the drive nozzle 12a of the ejector 12 and the refrigerant sucked from the ejector 12 suction part 12b are mixed by the mixing part 12c of the ejector 12 (point 9 in FIG. 6), and the pressure is increased by the diffuser 12d of the ejector 12 (FIG. 6). 6 points 10). Thereafter, after being heated and vaporized by the first internal heat exchanger 14 (11 in FIG. 6), the process returns to the suction of the compressor 3.

  The refrigerant bypassed to the injection circuit 21 is decompressed to the intermediate pressure by the third expansion valve 19 to become a low-temperature two-phase refrigerant (point 12 in FIG. 6), and then the second internal heat exchanger 20 and the high-pressure refrigerant. Heat is exchanged and heated (point 13 in FIG. 6) and injected into the pressure chamber of the compressor 3. Inside the compressor 3, after the sucked refrigerant (point 11 in FIG. 6) is compressed and heated to an intermediate pressure (point 14 in FIG. 6), it merges with the refrigerant to be injected and after the temperature drops (FIG. 6). Point 15), compressed to high pressure and discharged (point 1 in FIG. 6).

Next, operation during cooling operation will be described.
FIG. 7 is a Ph diagram showing the operating state of the refrigeration cycle apparatus of FIG. 5 during the cooling operation, and the operation will be described with reference to the refrigerant circuit of FIG. 5 and the Ph diagram of FIG. To do.
During the cooling operation, the flow path of the four-way valve 4 is set in the direction of the broken line in FIG. Then, the high-temperature and high-pressure gas refrigerant (point 1 in FIG. 7) discharged from the compressor 3 flows into the outdoor heat exchanger 11 acting as a condenser through the four-way valve 4, where it condenses and liquefies while radiating heat. (Point 2 in FIG. 7). The refrigerant leaving the outdoor heat exchanger 11 is slightly decompressed by the first expansion valve 10 (point 3 in FIG. 7), and then exchanges heat with the low-temperature refrigerant flowing through the injection circuit 21 by the second internal heat exchanger 20. After being cooled (point 4 in FIG. 7) and partially bypassing the refrigerant to the injection circuit 21, the first internal heat exchanger 14 continues to exchange heat with the refrigerant sucked into the compressor 3 and is cooled (FIG. 7). 7 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. 7), and then flows out of the outdoor unit 1 and flows into the indoor unit 2 through the liquid pipe 7. Then, it flows into the indoor heat exchanger 6 acting as an evaporator, absorbs heat therein, 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. 7).

  On the other hand, a part of the refrigerant (point 4 in FIG. 7) cooled by exchanging heat with the low-temperature refrigerant flowing through the injection circuit 21 in the second internal heat exchanger 20 is bypassed by the injection circuit 21, and the third expansion valve 19. The pressure is reduced to an intermediate pressure to become a low-temperature two-phase refrigerant (point 12 in FIG. 7), and then heat-exchanged with the high-pressure refrigerant in the second internal heat exchanger 20 and heated (point 13 in FIG. 7). It is injected into the room. Inside the compressor 3, after the sucked refrigerant (point 11 in FIG. 7) is compressed and heated to an intermediate pressure (point 14 in FIG. 7), it merges with the refrigerant to be injected and after the temperature drops (FIG. 7). Point 15), compressed to a high pressure and discharged (point 1 in FIG. 7).

  Further, a part of the high-pressure and low-temperature refrigerant (point 2 in FIG. 7) exiting the outdoor heat exchanger 11 flows into the drive nozzle 12a inlet side of the ejector 12 through the electromagnetic valve 13 from the second branch path 17, and the speed Then, the pressure is reduced (point 8 in FIG. 7), and the refrigerant (point 7 in FIG. 7) flowing out from the indoor heat exchanger 6 and guided to the suction part 12b of the ejector 12 is sucked. The refrigerant flowing out from the drive nozzle 12a of the ejector 12 and the refrigerant sucked from the suction part 12b of the ejector 12 are mixed by the mixing part 12c of the ejector 12 (point 9 in FIG. 7), and the pressure is increased by the diffuser 12d of the ejector 12 ( FIG. 7 point 10). Then, after being heated and vaporized by the first internal heat exchanger 14 (11 in FIG. 7), the process returns to the suction of the compressor 3. The Ph diagram during cooling operation is substantially the same as during heating operation, and the same operation can be realized in either operation mode.

Next, the operation control operation of this refrigeration cycle apparatus will be described.
Since each actuator operation in the refrigerant circuit is the same as that of the first embodiment except for the injection circuit 21, the operation of the third expansion valve 19 installed in the injection circuit 21 will be described.
First, the control operation during the heating operation will be described with reference to FIG.
The third expansion valve 19 is controlled so that the discharge temperature of the compressor 3 detected by the temperature sensor 18a becomes a preset target value, for example, 90 ° C. The refrigerant state change when the opening degree of the third expansion valve 19 is changed is as follows. When the opening degree of the third expansion valve 19 increases, the flow rate of the refrigerant flowing through the injection circuit 21 increases. The amount of heat exchange in the second internal heat exchanger 20 does not change greatly depending on the flow rate of the injection circuit 21. Therefore, when the flow rate of refrigerant flowing in the injection circuit 21 increases, the heat exchange amount on the injection circuit 21 side in the second internal heat exchanger 20 is increased. The refrigerant enthalpy difference (difference between points 12 and 13 in FIG. 6) becomes small, and the refrigerant enthalpy (point 13 in FIG. 6) to be injected decreases. Accordingly, the refrigerant enthalpy (point 15 in FIG. 6) after the injected refrigerant merges also decreases, and as a result, the enthalpy (point 1 in FIG. 6) of the refrigerant discharged from the compressor 3 also decreases, and the discharge temperature of the compressor 3 decreases. To do. Conversely, when the opening degree of the third expansion valve 19 decreases, the enthalpy of the refrigerant discharged from the compressor 3 increases and the discharge temperature of the compressor 3 increases. Therefore, the opening degree control of the third expansion valve 19 controls the opening degree of the third expansion valve 19 largely 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 19 is controlled to be small.

The control operation during the cooling operation will be described with reference to FIG.
Since the cooling operation is the same as that of the first embodiment except for the injection circuit 21 as in the case of the heating operation, the operation of the third expansion valve 19 installed in the injection circuit 21 will be described.
The third expansion valve 19 is controlled so that the discharge temperature of the compressor 3 detected by the temperature sensor 18a becomes a preset target value, for example, 90 ° C. The refrigerant state change when the opening degree of the third expansion valve 19 is changed is the same as that during the heating operation. When the discharge temperature of the compressor 3 is higher than the target value, the opening degree of the third expansion valve 19 is changed. When the discharge temperature is lower than the target value, the opening degree of the third expansion valve 19 is controlled to be small.

Next, functions and effects realized by the circuit configuration and control of the present embodiment will be described. In the configuration of the present refrigeration cycle apparatus, the same operation can be performed in any of the cooling and heating operations, and therefore the heating operation will be particularly described below.
The circuit configuration of the refrigeration cycle apparatus is such that an injection circuit 21 is added to a so-called ejector circuit. That is, the refrigerant that has been discharged from the condenser (during heating operation: the indoor heat exchanger 6) and then decompressed to an intermediate pressure is injected into the compressor 3. In the refrigeration cycle in which the ejector 12 is mounted, the pressure increase amount at the drive nozzle 12a is determined according to the expansion power recovered by the drive nozzle 12a of the ejector 12, and the effect of improving the cycle efficiency is determined. Therefore, the greater the difference in inlet / outlet refrigerant pressure at the drive nozzle 12a, that is, the higher the compression ratio operation, the greater the efficiency improvement effect. However, on the other hand, when the high compression ratio operation is performed, for example, in the heating operation, when the outdoor air temperature is a low outdoor air condition of 0 ° C. or less, the refrigerant circulation amount is reduced due to the decrease in the evaporation pressure or the compressor The discharged refrigerant temperature becomes excessively high, and the heating capacity cannot be sufficiently exhibited, or the operation itself cannot be continued, and the efficiency improvement effect of the ejector 12 cannot be obtained. However, by adopting the configuration of this refrigeration cycle apparatus, ejector-driven flow due to a decrease in the discharge temperature of the compressor 3 due to injection and an increase in the amount of refrigerant circulation to the condenser (heating operation: indoor heat exchanger 6) Therefore, the effect of improving the cycle efficiency of the ejector 12 is sufficiently exhibited.

  Furthermore, when the second internal heat exchanger 20 is provided in the injection circuit 21 as in the present embodiment, the injection refrigerant can be a two-phase refrigerant with a high degree of dryness, and the liquid refrigerant is used for injection. In comparison, since the enthalpy of the injection refrigerant can be increased, the compression work of the compressor 3 can be reduced correspondingly, and the efficiency of the cycle can be increased. On the other hand, the refrigerant enthalpy flowing into the evaporator is reduced by the second internal heat exchanger 20, and the refrigerant enthalpy difference in the evaporator is increased. Therefore, the cooling capacity increases even during the cooling operation.

Embodiment 4 FIG.
A fourth embodiment of the present invention is shown in FIG. FIG. 8 is a refrigerant circuit diagram of the refrigeration cycle apparatus according to the fourth embodiment. By mounting the ejector 12, the cycle rate is increased. With the configuration as shown in FIG. 8, for example, when the purpose is to improve the efficiency of the heating operation, such as a heater or a water heater for a cold region, the circuit is simplified compared to the first embodiment. Can be realized at low cost. That is, the refrigerant circuit of the fourth embodiment has a configuration in which the second branch passage 17 and the second expansion valve 8 are omitted in comparison with the refrigerant circuit of FIG. It is comprised so that a function may be exhibited.

An operation during heating operation of the refrigeration cycle apparatus will be described.
FIG. 9 is a Ph diagram showing an operation state during heating operation of the refrigerant circuit of FIG. 8, and an explanation of the operation is given with reference to the refrigerant circuit of FIG. 8 and the Ph diagram of FIG. 9. To do.
During the heating operation, the high-temperature and high-pressure gas refrigerant (point 1 in FIG. 9) discharged from the compressor 3 flows into the indoor heat exchanger 6 acting as a condenser, where it condenses and liquefies while dissipating heat, and the high-pressure and low-temperature refrigerant. (Point 2 in FIG. 9). The refrigerant that has exited the indoor heat exchanger 6 flows into the first internal heat exchanger 14 and is cooled by exchanging heat with the low-pressure refrigerant (point 3 in FIG. 9) and then decompressed by the first expansion valve 10 ( The point 4 in FIG. 9) flows to the outdoor heat exchanger 11 acting as an evaporator and reaches the outlet (point 5 in FIG. 9).

  On the other hand, a part of the refrigerant (point 2 in FIG. 9) exiting the indoor heat exchanger 6 flows from the first branch path (bypass circuit) 16 to the inlet side of the drive nozzle 12a of the ejector 12 through the electromagnetic valve 13, The pressure is reduced at the speed (point 6 in FIG. 9), and the refrigerant (point 5 in FIG. 9) flowing out from the outdoor heat exchanger 11 and guided to the suction part 12b of the ejector 12 is sucked. The refrigerant flowing out from the drive nozzle 12a of the ejector 12 and the refrigerant sucked from the suction part 12b of the ejector 12 are mixed by the mixing part 12c of the ejector 12 (point 7 in FIG. 9), and the pressure is increased by the diffuser 12d of the ejector 12 ( FIG. 9 point 8). Then, after being heated and vaporized by the internal heat exchanger 14 (point 9 in FIG. 9), the process returns to the suction of the compressor 3.

Embodiment 5 FIG.
A fifth embodiment of the present invention is shown in FIG.
FIG. 10 is a refrigerant circuit diagram of the refrigeration cycle apparatus according to the fifth embodiment. The ejector 12 is mounted to increase the cycle rate, and the injection circuit 21 is further mounted. With the configuration as shown in FIG. 10, when the purpose is to improve the efficiency of the heating operation, the circuit can be simplified compared to the third embodiment, and can be realized at a low cost. In the arrangement shown in FIG. 10, the first branch path 16 to the ejector 12 is upstream of the second internal heat exchanger 20 during heating operation. Since the refrigerant having a high enthalpy can flow through the ejector 12, the efficiency improvement effect of the ejector 12 can be kept high.

The operation of the refrigeration cycle apparatus during heating operation will be described.
FIG. 11 is a Ph diagram showing an operation state during heating operation of the refrigerant circuit of FIG. 10, and the operation is described with reference to the refrigerant circuit of FIG. 10 and the Ph diagram of FIG. 11. To do.
The high-temperature and high-pressure gas refrigerant (point 1 in FIG. 11) 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 radiating heat in the indoor heat exchanger 6 acting as a condenser to become a high-pressure and low-temperature liquid refrigerant (point 2 in FIG. 11), and the heat radiated from the refrigerant is transferred to the load side. Heating is performed by giving it to a load-side medium such as air or water. 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 then bypasses a part of the refrigerant to the first branching path 16 before the second internal heat exchange. The refrigerant in the injection circuit 21 is cooled by applying heat to the injection circuit 21 (point 3 in FIG. 11), and after a part of the refrigerant is bypassed to the injection circuit 21, the first internal heat exchanger 14 Heat is applied to the low-temperature refrigerant to cool it (point 4 in FIG. 11). Thereafter, the refrigerant is depressurized to a low pressure by the first expansion valve 10 to become a two-phase refrigerant (point 5 in FIG. 11), and then flows into the outdoor heat exchanger 11 acting as an evaporator, where it absorbs heat, evaporates, and is gasified. (Point 6 in FIG. 11).

  On the other hand, a part of the refrigerant (point 2 in FIG. 11) flowing into the outdoor unit 1 flows into the drive nozzle 12a inlet side of the ejector 12 through the electromagnetic valve 13 from the first branch path 16, and is decompressed to obtain speed. (FIG. 11 point 7), the refrigerant | coolant (FIG. 11 point 6) which flowed out of the outdoor heat exchanger 11 and was guide | induced to the suction part 12b of the ejector 12 is attracted | sucked. The refrigerant flowing out from the drive nozzle 12a of the ejector 12 and the refrigerant sucked from the ejector 12 suction unit 12b are mixed by the mixing unit 12c of the ejector 12 (point 8 in FIG. 11), and the pressure is increased by the diffuser 12d of the ejector 12 (FIG. 11). 11 points 9). Then, after being heated and vaporized by the first internal heat exchanger 14 (point 10 in FIG. 11), the process returns to the suction of the compressor 3.

  The refrigerant bypassed to the injection circuit 21 is decompressed to the intermediate pressure by the third expansion valve 19 to become a low-temperature two-phase refrigerant (point 11 in FIG. 11), and then the high-pressure refrigerant is converted into the second internal heat exchanger 20. Heat is exchanged and heated (point 12 in FIG. 11) and injected into the pressure chamber of the compressor 3. Inside the compressor 3, after the sucked refrigerant (point 10 in FIG. 11) is compressed and heated to an intermediate pressure (point 13 in FIG. 11), it merges with the refrigerant to be injected and after the temperature drops (FIG. 11). Point 14), compressed to high pressure and discharged (point 1 in FIG. 11).

Embodiment 6 FIG.
A sixth embodiment of the present invention is shown in FIG.
FIG. 12 is a refrigerant circuit diagram of the refrigeration cycle apparatus according to Embodiment 6. The ejector 12 is mounted to increase the cycle rate, and the injection circuit 21 is further mounted. With the configuration as shown in FIG. 12, by providing expansion valves before and after the first internal heat exchanger 14, the state of the refrigerant flowing into the drive unit of the ejector 12, and the refrigerant flowing through the evaporator to the ejector suction port Since the amount can be individually controlled, it becomes possible to always control to the optimum state regardless of the cycle operation state as compared with the fifth embodiment, and the improvement effect of the ejector can be obtained.

The operation of the refrigeration cycle apparatus during heating operation will be described.
FIG. 13 is a Ph diagram showing the operation status during the heating operation of the refrigerant circuit of FIG. 12, and the operation will be described with reference to the refrigerant circuit of FIG. 12 and the Ph diagram of FIG. To do. The sixth embodiment is different from the refrigerant circuit of FIG. 10 in that the second expansion valve 8 is provided as described above, and the Ph diagram of FIG. The characteristic after the second expansion valve 8 is different from the Ph diagram of FIG.
The high-temperature and high-pressure gas refrigerant (point 1 in FIG. 13) 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 radiating heat in the indoor heat exchanger 6 acting as a condenser to become a high-pressure and low-temperature liquid refrigerant (point 2 in FIG. 13), and the heat radiated from the refrigerant is transferred to the load side. Heating is performed by giving it to a load-side medium such as air or water. 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 then bypasses a part of the refrigerant to the first branching path 16 before the second internal heat exchange. Heat is supplied to the refrigerant in the injection circuit 21 by the vessel 20 to be cooled (point 3 in FIG. 13), and after a part of the refrigerant is bypassed to the injection circuit 21, the pressure is reduced by the second expansion valve 8 (point 4 in FIG. 13). ), The first internal heat exchanger 14 heats and cools the low-temperature refrigerant sucked by the compressor 3 (point 5 in FIG. 13). Thereafter, the refrigerant is depressurized to a low pressure by the first expansion valve 10 to become a two-phase refrigerant (point 6 in FIG. 13), and then flows into the outdoor heat exchanger 11 acting as an evaporator, where it absorbs heat, evaporates, and is gasified. (Point 7 in FIG. 13).

  On the other hand, a part of the refrigerant (point 2 in FIG. 13) flowing into the outdoor unit 1 flows into the drive nozzle 12a inlet side of the ejector 12 from the first branch path 16 through the electromagnetic valve 13, and is decompressed with speed. (Point 8 in FIG. 13), the refrigerant (point 7 in FIG. 13) flowing out from the outdoor heat exchanger 11 and guided to the suction part 12b of the ejector 12 is sucked. The refrigerant flowing out from the drive nozzle 12a of the ejector 12 and the refrigerant sucked from the suction part 12b of the ejector 12 are mixed by the mixing part 12c of the ejector 12 (point 9 in FIG. 13), and the pressure is increased by the diffuser 12d of the ejector 12 ( FIG. 13 point 10). Thereafter, after being heated and vaporized by the first internal heat exchanger 14 (11 in FIG. 13), the process returns to the suction of the compressor 3.

  Further, the refrigerant bypassed to the injection circuit 21 is decompressed to the intermediate pressure by the third expansion valve 19 and becomes a low-temperature two-phase refrigerant (point 12 in FIG. 13), and then the high-pressure refrigerant is converted by the second internal heat exchanger 20. Heat is exchanged and heated (13 in FIG. 13) and injected into the pressure chamber of the compressor 3. Inside the compressor 3, after the sucked refrigerant (point 11 in FIG. 13) is compressed and heated to an intermediate pressure (point 14 in FIG. 13), it merges with the refrigerant to be injected and the temperature drops (FIG. 13). Point 15), compressed to high pressure and discharged (point 1 in FIG. 13).

Embodiment 7 FIG.
The refrigerant of the refrigeration cycle apparatus is not limited to R410A, but is used for other refrigerants, HFC refrigerants R134a and R404A, R407C, natural refrigerants CO2, HC refrigerants, ammonia, air, water, and the like. be able to.

  In the refrigeration cycle apparatus according to Embodiments 1 to 6, the outdoor unit 1 includes the ejector 12 and the like, and the existing refrigeration cycle apparatus is changed due to, for example, a failure of the outdoor unit. In this case, even if only the outdoor unit 1 is changed and the indoor unit 2 and the extension pipe are diverted, the improvement effect of the ejector 12 can be obtained in the same manner regardless of the form of the indoor unit 2, and high-efficiency operation is realized. can do.

  Moreover, in said Embodiment 3-Embodiment 6, although the example using the 1st internal heat exchanger 14 was demonstrated, you may replace this with the intermediate pressure receiver 9 of said Embodiment 2. FIG. .

It is a refrigerant circuit figure of the refrigerating cycle device concerning Embodiment 1 of the present invention. It is a Ph diagram showing the operating condition of the refrigerating cycle device concerning Embodiment 1 of the present invention. It is a refrigerant circuit figure of the refrigerating cycle device concerning Embodiment 2 of the present invention. It is a Ph diagram showing the operating condition of the refrigerating cycle device concerning Embodiment 2 of the present invention. It is a refrigerant circuit figure of the refrigerating cycle device concerning Embodiment 3 of the present invention. It is a Ph diagram showing the heating operation situation of the refrigerating cycle device concerning Embodiment 3 of the present invention. It is a Ph diagram showing the cooling operation situation of the refrigerating cycle device concerning Embodiment 3 of the present invention. It is a refrigerant circuit figure of the refrigerating cycle device concerning Embodiment 4 of the present invention. It is a Ph diagram showing the operating condition of the refrigerating cycle device concerning Embodiment 4 of the present invention. It is a refrigerant circuit figure of the refrigerating cycle device concerning Embodiment 5 of the present invention. It is a Ph diagram showing the operating condition of the refrigerating cycle device concerning Embodiment 5 of the present invention. It is a refrigerant circuit figure of the refrigerating cycle device concerning Embodiment 6 of the present invention. It is a Ph diagram showing the operating condition of the refrigerating cycle device concerning Embodiment 6 of the present invention.

Explanation of symbols

  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 Medium pressure receiver with internal heat exchange function, 10 1st expansion Valve, 11 Outdoor heat exchanger, 12 Ejector, 13 Solenoid valve, 14 First internal heat exchanger, 15 Check valve, 16 First branch, 17 Second branch, 18 Temperature sensor, 19 Third expansion valve, 20 2nd internal heat exchanger, 21 injection circuit, 22 measurement control apparatus.

Claims (11)

A compressor, a flow path switching means, a heat source side heat exchanger, a first pressure reducing device, a first internal heat exchanger, a second pressure reducing device, a use side heat exchanger, and an ejector, which are flow path switching means A refrigeration cycle apparatus comprising a refrigerant circuit that is connected in a predetermined sequential annular manner corresponding to heating operation or cooling operation by switching according to
At the time of heating operation, a first branch path branched from between the use side heat exchanger and the second pressure reducing device, and a refrigerant flows to a drive nozzle of the ejector;
At the time of cooling operation, a branch is made from between the heat source side heat exchanger and the first pressure reducing device, and a second branch passage through which refrigerant flows to the drive nozzle of the ejector,
The first internal heat exchanger exchanges heat between the refrigerant flowing from the pressure raising unit of the ejector to the suction port of the compressor and the refrigerant flowing between the first pressure reducing device and the second pressure reducing device. A refrigeration cycle apparatus characterized by that. The first internal heat exchanger includes a receiver provided between the first decompression device and the second decompression device, and sucks the compressor from the refrigerant in the receiver and the booster of the ejector. The refrigeration cycle apparatus according to claim 1, wherein heat exchange is performed with the refrigerant flowing in the mouth. The refrigeration cycle according to claim 1, further comprising an injection circuit that branches a refrigerant between the use side heat exchanger and the heat source side heat exchanger and injects the refrigerant into a compression chamber in the compressor. apparatus. The injection circuit heat-exchanges the third decompression device, the refrigerant decompressed by the third decompression device, and the refrigerant between the first decompression device and the second decompression device. The refrigeration cycle apparatus according to claim 3, further comprising an internal heat exchanger. A compressor, a flow path switching means, a heat source side heat exchanger, a first pressure reducing device, a first internal heat exchanger, a use side heat exchanger, and an ejector, which are operated by heating by switching by the flow path switching means or A refrigeration cycle apparatus including a refrigerant circuit that is connected in a predetermined annular manner corresponding to a cooling operation,
A first branch path that branches from between the use side heat exchanger and the second pressure reducing device and through which refrigerant flows to a drive nozzle of the ejector;
The first internal heat exchanger exchanges heat between the refrigerant flowing from the pressure raising unit of the ejector to the suction port of the compressor and the refrigerant flowing between the second pressure reducing device and the first pressure reducing device. A refrigeration cycle apparatus characterized by that. The first internal heat exchanger includes a receiver provided between the use-side heat exchanger and the first pressure reducing device, and sucks the compressor from the refrigerant in the receiver and the pressure booster of the ejector. 6. The refrigeration cycle apparatus according to claim 5, wherein heat exchange is performed with the refrigerant flowing through the mouth. The refrigeration cycle according to claim 5 or 6, further comprising an injection circuit for branching a refrigerant between the use side heat exchanger and the first decompression device and injecting the refrigerant into a compression chamber in the compressor. apparatus. The injection circuit is configured to exchange heat between a third decompression device and the refrigerant decompressed by the third decompression device and the refrigerant between the use-side heat exchanger and the first decompression device. The refrigeration cycle apparatus according to claim 4, further comprising an internal heat exchanger.   The branch point of the injection circuit, the second internal heat exchanger, and the first internal heat exchanger are arranged between the branch point of the first branch path and the first pressure reducing device. The refrigeration cycle apparatus according to claim 8. A second decompression device is provided immediately before the first internal heat exchanger with respect to the flow direction of the refrigerant flowing from the use side heat exchanger to the first internal heat exchanger during heating operation. The refrigeration cycle apparatus according to any one of claims 5 to 9. The refrigeration cycle apparatus according to any one of claims 1 to 10, wherein the ejector is mounted on an outdoor unit on which the heat source side heat exchanger is mounted.

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