JP7146117B2 - refrigeration cycle equipment - Google Patents

Description

The present invention relates to a refrigerating cycle device.

Conventionally, a binary refrigeration cycle device having a high temperature side refrigerant circuit and a low temperature side refrigerant circuit has been used. For example, International Publication No. 2018/008053 (Patent Document 1) describes a dual refrigeration cycle apparatus. In this binary refrigerating cycle apparatus, increasing the subcooling (degree of supercooling) in the cascade heat exchanger increases the enthalpy difference, so that the capacity can be increased.

International Publication No. 2018/008053

The binary refrigerating cycle device described in the above publication functions only as a refrigerator. Therefore, it is impossible to increase the capacity of both cooling and heating.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and an object thereof is to provide a refrigeration cycle apparatus capable of increasing both cooling and heating capacity.

A refrigeration cycle apparatus of the present invention includes a high temperature side refrigerant circuit, a low temperature side refrigerant circuit, and a heat medium circuit. The high temperature side refrigerant circuit has a high temperature side compressor, a hexagonal valve, a high temperature side refrigerant heat exchanger, a high temperature side expansion valve, a cascade heat exchanger and a first heat medium heat exchanger, and has a high temperature side refrigerant. circulate. The low-side refrigerant circuit has a low-side compressor, a four-way valve, a cascade heat exchanger, a low-side expansion valve, and a second heat medium heat exchanger, and circulates the low-side refrigerant. The heat medium circuit circulates the heat medium through the first heat medium heat exchanger and the second heat medium heat exchanger. During cooling operation, the high temperature side refrigerant circuit is configured so that the high temperature side refrigerant flows in the order of the high temperature side compressor, the 6-way valve, the high temperature side refrigerant heat exchanger, the high temperature side expansion valve, the cascade heat exchanger, and the 6-way valve. The six-way valve is switched, and the low-side refrigerant flows through the low-side refrigerant circuit in the order of the low-side compressor, the four-way valve, the cascade heat exchanger, the low-side expansion valve, the second heat medium heat exchanger, and the four-way valve. , heat exchange is performed between the heat medium flowing through the heat medium circuit and the low temperature side refrigerant circulating in the low temperature side refrigerant circuit in the second heat medium heat exchanger. During heating operation, the high-side refrigerant circuit consists of the high-side compressor, the 6-way valve, the first heat medium heat exchanger, the 6-way valve, the cascade heat exchanger, the high-side expansion valve, the high-side refrigerant heat exchanger, the 6-way The hexagonal valves are switched so that the high temperature side refrigerant flows in the order of the valves, and the low temperature side refrigerant circuit is composed of the low temperature side compressor, the four-way valve, the second heat medium heat exchanger, the low temperature side expansion valve, and the cascade heat exchanger. , the four-way valves are switched so that the low temperature side refrigerant flows in the order of the four way valves, and in the second heat medium heat exchanger, the heat medium flowing through the heat medium circuit and the low temperature side refrigerant circulating in the low temperature side refrigerant circuit are switched. In the first heat medium heat exchanger, heat exchange is performed between the heat medium circulating in the heat medium circuit and the high temperature side refrigerant circulating in the high temperature side refrigerant circuit.

According to the refrigerating cycle apparatus of the present invention, heat exchange is performed between the high temperature side refrigerant and the low temperature side refrigerant in the cascade heat exchanger during cooling operation. During heating operation, heat is exchanged between the high temperature side refrigerant and the low temperature side refrigerant in the cascade heat exchanger, and heat exchange is performed between the high temperature side refrigerant and the heat medium in the first heat medium heat exchanger. done. Therefore, it is possible to increase the capacity of both cooling and heating.

1 is a refrigerant circuit diagram of a refrigeration cycle device according to an embodiment; FIG. FIG. 2 is a refrigerant circuit diagram showing the flow of a high temperature side refrigerant during cooling operation in the hexagonal valve of FIG. 1 ; FIG. 2 is a refrigerant circuit diagram showing the flow of high temperature side refrigerant during heating operation in the hexagonal valve of FIG. 1 ; FIG. 4 is a schematic cross-sectional view showing the structure of an example of a hexagonal valve and its operation during cooling operation; FIG. 4 is a schematic cross-sectional view showing the structure of an example of a hexagonal valve and its operation during heating operation; FIG. 2 is a refrigerant circuit diagram showing the flow of high-pressure side refrigerant and heat medium in the first heat medium heat exchanger of FIG. 1 ;

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. In the following description, the same reference numerals are given to the same or corresponding parts, and redundant description will not be repeated. In the embodiment, a chiller will be described as an example of a refrigeration cycle device.

A configuration of a refrigeration cycle apparatus 1 according to an embodiment will be described with reference to FIG.
The refrigeration cycle device 1 includes a high temperature side refrigerant circuit 10 , a low temperature side refrigerant circuit 20 , a heat medium circuit 30 and a control device 40 .

The high-side refrigerant circuit 10 includes a high-side compressor 11, a six-way valve 12, a high-side refrigerant heat exchanger 13, a high-side expansion valve 14, a cascade heat exchanger 15, and a first heat medium heat exchanger 16. have. The high temperature side compressor 11, the six-way valve 12, the high temperature side refrigerant heat exchanger 13, the high temperature side expansion valve 14, the cascade heat exchanger 15 and the first heat medium heat exchanger 16 are connected by piping. The high temperature side refrigerant circuit 10 is configured to circulate the high temperature side refrigerant.

The high pressure side compressor 11 is configured to compress the high pressure side refrigerant. The high-side compressor 11 has a suction port and a discharge port. The high temperature side compressor 11 is configured to compress the high temperature side refrigerant sucked from the suction port and discharge it from the discharge port. The high-side compressor 11 is configured to have a variable capacity. The high-voltage side compressor 11 may be configured to change its capacity by adjusting the rotational speed of the high-voltage side compressor 11 based on an instruction from the control device 40 .

The hexagonal valve 12 is connected to the high temperature side compressor 11 , the high temperature side refrigerant heat exchanger 13 , the cascade heat exchanger 15 and the first heat medium heat exchanger 16 . The hexagonal valve 12 directs the high temperature side refrigerant compressed by the high temperature side compressor 11 to either the high temperature side refrigerant heat exchanger 13 or the first heat medium heat exchanger 16 to the cascade heat exchanger 15. It is configured to be switchable so as to flow. Specifically, the six-way valve 12 allows the high-side refrigerant discharged from the high-side compressor 11 during cooling operation to flow to the high-side refrigerant heat exchanger 13, and discharges it from the high-side compressor 11 during heating operation. The flow of the high temperature side refrigerant is switched so that the high temperature side refrigerant flows to the cascade heat exchanger 15 via the first heat medium heat exchanger 16 .

During cooling operation, the hexagonal valve 12 connects the high-side refrigerant circuit 10 to the high-side compressor 11, the 6-way valve 12, the high-side refrigerant heat exchanger 13, the high-side expansion valve 14, the cascade heat exchanger 15, and the hexagonal heat exchanger. The valves 12 are configured to be switchable so that the high-side refrigerant flows in order.

During heating operation, the hexagonal valve 12 connects the high-side refrigerant circuit 10 to the high-side compressor 11, the 6-way valve 12, the first heat medium heat exchanger 16, the 6-way valve 12, the cascade heat exchanger 15, the high-side expansion The valve 14, the high temperature side refrigerant heat exchanger 13, and the hexagonal valve 12 are configured to be switchable so that the high temperature side refrigerant flows in this order.

The high temperature side refrigerant heat exchanger 13 is configured to exchange heat between the high temperature side refrigerant flowing inside the high temperature side refrigerant heat exchanger 13 and the air around the high temperature side refrigerant heat exchanger 13. ing. The high temperature side refrigerant heat exchanger 13 is connected to the hexagonal valve 12 and the high temperature side expansion valve 14 . The high temperature side refrigerant heat exchanger 13 functions as a condenser that condenses the high temperature side refrigerant during cooling operation, and functions as an evaporator that evaporates the high temperature side refrigerant during heating operation. The high-voltage side refrigerant heat exchanger 13 is, for example, a plate-fin tube heat exchanger having a plurality of fins and tubes passing through the plurality of fins.

The high pressure side expansion valve 14 is configured to reduce the pressure by expanding the high pressure side refrigerant condensed by the condenser. The high-pressure side expansion valve 14 is connected to the high-pressure side refrigerant heat exchanger 13 and the cascade heat exchanger 15 . The high-side expansion valve 14 serves as a throttle device for decompressing the high-side refrigerant condensed by the high-side refrigerant heat exchanger 13 during cooling operation, and the high-side refrigerant condensed by the cascade heat exchanger 15 during heating operation. It becomes a throttling device that reduces the pressure of High-side expansion valve 14 is, for example, a solenoid valve or a capillary tube.

The cascade heat exchanger 15 is configured to exchange heat between the high temperature side refrigerant circulating in the high temperature side refrigerant circuit 10 and the low temperature side refrigerant circulating in the low temperature side refrigerant circuit 20 . The cascade heat exchanger 15 is connected to the high-side expansion valve 14 and the hexagonal valve 12 . The cascade heat exchanger 15 is also connected to the low temperature side refrigerant heat exchanger 23 and the low temperature side expansion valve 24 . The cascade heat exchanger 15 functions as an evaporator that evaporates the high temperature side refrigerant during cooling operation, and functions as a condenser that condenses the high temperature side refrigerant during heating operation.

The first heat medium heat exchanger 16 is configured to exchange heat between the high temperature side refrigerant circulating in the high temperature side refrigerant circuit 10 and the heat medium circulating in the heat medium circuit 30 . The first heat medium heat exchanger 16 is connected to the hexagonal valve 12 . The first heat medium heat exchanger 16 is configured such that the high temperature side refrigerant does not circulate during the cooling operation, and the high temperature side refrigerant circulates during the heating operation.

The first heat medium heat exchanger 16 is configured so that heat exchange is not performed between the heat medium circulating in the heat medium circuit 30 and the high temperature side refrigerant circulating in the high temperature side refrigerant circuit 10 during cooling operation. It is

The first heat medium heat exchanger 16 is configured to perform heat exchange between the heat medium circulating in the heat medium circuit 30 and the high temperature side refrigerant circulating in the high temperature side refrigerant circuit 10 during the heating operation. ing.

The low-side refrigerant circuit 20 includes a low-side compressor 21 , a four-way valve 22 , a low-side refrigerant heat exchanger 23 , a cascade heat exchanger 15 , a low-side expansion valve 24 and a second heat medium heat exchanger 25 . have. The low-side compressor 21, the four-way valve 22, the low-side refrigerant heat exchanger 23, the cascade heat exchanger 15, the low-side expansion valve 24, and the second heat medium heat exchanger 25 are connected by piping. The low temperature side refrigerant circuit 20 is configured to circulate the low temperature side refrigerant.

The low-voltage side compressor 21 is configured to compress the low-voltage side refrigerant. The low pressure side compressor 21 has a suction port and a discharge port. The low temperature side compressor 21 is configured to compress the low temperature side refrigerant sucked from the suction port and discharge it from the discharge port. The low-voltage side compressor 21 is configured to have a variable capacity. The low-voltage side compressor 21 may be configured such that the displacement is changed by adjusting the rotational speed of the low-voltage side compressor 21 based on an instruction from the control device 40 .

The four-way valve 22 is connected to the low temperature side compressor 21 , the low temperature side refrigerant heat exchanger 23 and the second heat medium heat exchanger 25 . The four-way valve 22 is configured to be switchable so as to flow the low temperature side refrigerant compressed by the low temperature side compressor 21 to either the low temperature side refrigerant heat exchanger 23 or the second heat medium heat exchanger 25. there is Specifically, the four-way valve 22 allows the low temperature side refrigerant discharged from the low temperature side compressor 21 to flow to the low temperature side refrigerant heat exchanger 23 during cooling operation, and discharges it from the low temperature side compressor 21 during heating operation. It is configured to switch the flow of the low temperature side refrigerant so as to flow the low temperature side refrigerant to the second heat medium heat exchanger 25 .

During cooling operation, the four-way valve 22 connects the low-side refrigerant circuit 20 to the low-side compressor 21, the four-way valve 22, the cascade heat exchanger 15, the low-side expansion valve 24, the second heat medium heat exchanger 25, and the four-way heat exchanger. It is configured to be switchable so that the low-concentration side refrigerant flows in order of the valves 22 .

During heating operation, the four-way valve 22 connects the low-side refrigerant circuit 20 to the low-side compressor 21, the four-way valve 22, the second heat medium heat exchanger 25, the low-side expansion valve 24, the cascade heat exchanger 15, and the four-way heat exchanger. It is configured to be switchable so that the low-concentration side refrigerant flows in order of the valves 22 .

The low temperature side refrigerant heat exchanger 23 is configured to perform heat exchange between the low temperature side refrigerant flowing inside the low temperature side refrigerant heat exchanger 23 and the air around the low temperature side refrigerant heat exchanger 23. ing. The low-side refrigerant heat exchanger 23 is an auxiliary heat exchanger. The low-side refrigerant heat exchanger 23 is connected to the four-way valve 22 and the cascade heat exchanger 15 . The low temperature side refrigerant heat exchanger 23 functions as a condenser that condenses the low temperature side refrigerant during cooling operation, and functions as an evaporator that evaporates the low temperature side refrigerant during heating operation. The low-side refrigerant heat exchanger 23 is, for example, a plate-fin tube heat exchanger having a plurality of fins and tubes passing through the plurality of fins.

The low-side expansion valve 24 is configured to reduce the pressure by expanding the low-side refrigerant condensed in the condenser. The low-side expansion valve 24 is connected to the cascade heat exchanger 15 and the second heat medium heat exchanger 25 . The low-side expansion valve 24 serves as a throttle device for decompressing the low-side refrigerant condensed by the low-side refrigerant heat exchanger 23 and the cascade heat exchanger 15 during cooling operation, and serves as a second heat medium heat exchanger during heating operation. 25 serves as an expansion device for decompressing the low-side refrigerant condensed. The low-side expansion valve 24 is, for example, an electromagnetic valve or a carrier tube.

The second heat medium heat exchanger 25 is configured to exchange heat between the low temperature side refrigerant circulating in the low temperature side refrigerant circuit 20 and the heat medium circulating in the heat medium circuit 30 . The second heat medium heat exchanger 25 is connected to the low-side expansion valve 24 and the four-way valve 22 . The second heat medium heat exchanger 25 functions as an evaporator that evaporates the low temperature side refrigerant during cooling operation, and functions as a condenser that condenses the low temperature side refrigerant during heating operation.

The second heat medium heat exchanger 25 is configured to perform heat exchange between the heat medium circulating in the heat medium circuit 30 and the low temperature side refrigerant circulating in the low temperature side refrigerant circuit 20 during cooling operation. ing.

The second heat medium heat exchanger 25 is configured to perform heat exchange between the heat medium circulating in the heat medium circuit 30 and the low temperature side refrigerant circulating in the low temperature side refrigerant circuit 20 during the heating operation. ing.

The heat medium circuit 30 is configured to circulate the heat medium through the first heat medium heat exchanger 16 and the second heat medium heat exchanger 25 . The first heat medium heat exchanger 16 and the second heat medium heat exchanger 25 are connected by piping. The heat medium is, for example, water or antifreeze. The heat medium circuit 30 is, for example, connected to a radiator and configured to supply the heat medium to the radiator. This radiator is, for example, a showcase.

The high-side refrigerant is, for example, a combustible refrigerant, and the low-side refrigerant is, for example, a nonflammable refrigerant. Specifically, the high-side refrigerant is, for example, propane, and the low-side refrigerant is, for example, carbon dioxide (CO ₂ ). Also, the high-side refrigerant is, for example, R32, and the low-side refrigerant is, for example, carbon dioxide (CO ₂ ).

The control device 40 is configured to perform calculations, instructions, etc., and control each means, equipment, etc. of the refrigeration cycle apparatus.

Next, operation of the refrigeration cycle apparatus 1 according to the embodiment will be described with reference to FIG.

First, the operation of the refrigeration cycle device 1 during cooling operation will be described. The cooling operation is an operation in which the high-side refrigerant circuit 10, the low-side refrigerant circuit 20, and the heat medium circuit 30 are operated, and the space around a radiator (not shown) is cooled by the heat medium flowing through the heat medium circuit 30. .

In the high temperature side refrigerant circuit 10, during cooling operation, the high temperature side refrigerant circuit 10 includes a high temperature side compressor 11, a six-way valve 12, a high temperature side refrigerant heat exchanger 13, a high temperature side expansion valve 14, and a cascade heat exchange. The hexagonal valve 12 is switched so that the high temperature side refrigerant flows in the order of the vessel 15 and the hexagonal valve 12 .

The high temperature side compressor 11 compresses the high temperature side refrigerant. As a result, the high-side refrigerant becomes a high-temperature, high-pressure gas state. This high temperature and high pressure gas state high temperature side refrigerant is discharged from the high temperature side compressor 11, passes through the hexagonal valve 12, and is condensed by radiating heat to the air in the high temperature side refrigerant heat exchanger 13. , becomes a high-pressure liquid state. This high pressure liquid state high pressure side refrigerant flows into the high pressure side expansion valve 14 and is decompressed by being expanded by the high pressure side expansion valve 14 to become a low temperature and low pressure gas-liquid two-phase state.

This low-temperature, low-pressure gas-liquid two-phase high-side refrigerant flows through the cascade heat exchanger 15 and evaporates as heat is exchanged with the low-side refrigerant circulating in the low-side refrigerant circuit 20 . , to a low-pressure gas state. This low-pressure gaseous high-side refrigerant returns to the high-side compressor 11 via the six-way valve 12 and is compressed by the high-side compressor 11 . In this way, the high temperature side refrigerant circulates in the high temperature side refrigerant circuit during the cooling operation.

In the low energy side refrigerant circuit 20, the low energy side refrigerant circuit 20 includes a low energy side compressor 21, a four-way valve 22, a cascade heat exchanger 15, a low energy side expansion valve 24, a second heat medium heat exchanger 25, and a four way heat exchanger. The four-way valves 22 are switched so that the low-side refrigerant flows in order of the valves 22 .

The low temperature side compressor 21 compresses the low temperature side refrigerant. As a result, the low-side refrigerant enters a high-temperature, high-pressure gas state. This high-temperature, high-pressure gaseous low-side refrigerant is discharged from the high-side compressor 11, passes through the four-way valve 22, and is condensed by dissipating heat to the air in the low-side refrigerant heat exchanger 23. . The low temperature side refrigerant condensed in the low temperature side refrigerant heat exchanger 23 flows to the cascade heat exchanger 15, and heat exchange is performed with the high temperature side refrigerant circulating in the high temperature side refrigerant circuit 10. By condensing at , it becomes a high-pressure liquid state. This high-pressure liquid state low-side refrigerant flows into the low-side expansion valve 24 and is decompressed by being expanded by the low-side expansion valve 24 to become a low-temperature, low-pressure gas-liquid two-phase state.

This low-temperature, low-pressure gas-liquid two-phase low-side refrigerant flows to the second heat medium heat exchanger 25 and evaporates as heat is exchanged with the heat medium flowing through the heat medium circuit 30. It becomes a low-pressure gas state.

This low-pressure gaseous low-side refrigerant returns to the low-side compressor 21 via the four-way valve 22 and is compressed by the low-side compressor 21 . In this manner, the low temperature side refrigerant circulates in the low temperature side refrigerant circuit during the cooling operation.

In the heat medium circuit 30 , the heat medium flows through the first heat medium heat exchanger 16 and the second heat medium heat exchanger 25 . In the second heat medium heat exchanger 25 , heat exchange is performed between the heat medium circulating in the heat medium circuit 30 and the low temperature side refrigerant circulating in the low temperature side refrigerant circuit 20 . During cooling operation, heat is exchanged between the low temperature side refrigerant circulating in the low temperature side refrigerant circuit 20 and the heat medium circulating in the heat medium circuit 30 in the second heat medium heat exchanger 25, whereby the heat medium is Cooled.

Next, the operation of the refrigeration cycle device 1 during heating operation will be described. The heating operation is an operation in which the high-side refrigerant circuit 10, the low-side refrigerant circuit 20, and the heat medium circuit 30 are operated, and the space around a radiator (not shown) is warmed by the heat medium flowing through the heat medium circuit 30. .

In the high temperature side refrigerant circuit 10, during heating operation, the high temperature side refrigerant circuit 10 includes a high temperature side compressor 11, a hexagonal valve 12, a first heat medium heat exchanger 16, a hexagonal valve 12, a cascade heat exchanger 15, The hexagonal valve 12 is switched so that the high temperature side refrigerant flows in the order of the high temperature side expansion valve 14, the high temperature side refrigerant heat exchanger 13, and the 6-way valve 12.

The high temperature side compressor 11 compresses the high temperature side refrigerant. As a result, the high-side refrigerant becomes a high-temperature, high-pressure gas state. This high-temperature high-pressure gas state high-pressure side refrigerant is discharged from the high-side compressor 11, flows through the hexagonal valve 12 to the first heat medium heat exchanger 16, and flows through the heat medium circuit 30. It condenses by heat exchange being performed between. The high temperature side refrigerant condensed in the first heat medium heat exchanger 16 flows through the hexagonal valve 12 to the cascade heat exchanger 15, and flows between the low temperature side refrigerant circulating in the low temperature side refrigerant circuit 20. As heat is exchanged, it condenses into a high-pressure liquid state. This high pressure liquid state high pressure side refrigerant flows into the high pressure side expansion valve 14 and is decompressed by being expanded by the high pressure side expansion valve 14 to become a low temperature and low pressure gas-liquid two-phase state.

This low-temperature, low-pressure gas-liquid two-phase high-side refrigerant undergoes heat exchange with the air in the high-side refrigerant heat exchanger 13 to evaporate and become a low-pressure gas state. This low-pressure gaseous high-side refrigerant returns to the high-side compressor 11 via the six-way valve 12 and is compressed by the high-side compressor 11 . In this manner, the high temperature side refrigerant circulates in the high temperature side refrigerant circuit during the heating operation.

In the low energy side refrigerant circuit 20, the low energy side refrigerant circuit 20 includes a low energy side compressor 21, a four-way valve 22, a second heat medium heat exchanger 25, a low energy side expansion valve 24, a cascade heat exchanger 15, and a four way heat exchanger. The four-way valves 22 are switched so that the low-side refrigerant flows in order of the valves 22 .

The low temperature side compressor 21 compresses the low temperature side refrigerant. As a result, the low-side refrigerant enters a high-temperature, high-pressure gas state. This high-temperature, high-pressure gas state low-side refrigerant is discharged from the low-side compressor 21, flows to the second heat medium heat exchanger 25 via the four-way valve 22, and flows through the heat medium circuit 30 as a heat medium. It is condensed by heat exchange between and becomes a high-pressure liquid state. This high-pressure liquid state low-side refrigerant flows into the low-side expansion valve 24 and is manually expanded by the low-side expansion valve 24 to be decompressed into a low-temperature, low-pressure gas-liquid two-phase state.

This low-temperature, low-pressure gas-liquid two-phase high-temperature-side refrigerant flows through the cascade heat exchanger 15 and evaporates as heat is exchanged with the high-temperature-side refrigerant circulating in the high-temperature-side refrigerant circuit 10. . The low-side refrigerant evaporated in the cascade heat exchanger 15 is heat-exchanged with the air in the low-side refrigerant heat exchanger 23 to evaporate and become a low-pressure gas. This low-pressure gaseous low-side refrigerant returns to the low-side compressor 21 via the four-way valve 22 and is compressed by the low-side compressor 21 . In this manner, the low temperature side refrigerant circulates in the low temperature side refrigerant circuit during heating operation.

In the heat medium circuit 30 , the heat medium flows through the first heat medium heat exchanger 16 and the second heat medium heat exchanger 25 . In the second heat medium heat exchanger 25 , heat exchange is performed between the heat medium circulating in the heat medium circuit 30 and the low temperature side refrigerant circulating in the low temperature side refrigerant circuit 20 . Furthermore, in the first heat medium heat exchanger 16 , heat exchange is performed between the heat medium circulating in the heat medium circuit 30 and the high temperature side refrigerant circulating in the high temperature side refrigerant circuit 10 .

During heating operation, heat is exchanged in the first heat medium heat exchanger 16 between the high temperature side refrigerant circulating in the high temperature side refrigerant circuit 10 and the heat medium circulating in the heat medium circuit 30. The low temperature side refrigerant circulating in the low temperature side refrigerant circuit 20 and the heat medium circulating in the heat medium circuit 30 are heat-exchanged in the heat medium heat exchanger 25 to heat the heat medium.

Next, the hexagonal valve 12 of the refrigeration cycle apparatus 1 according to the embodiment will be described in detail with reference to FIGS. 1 to 5. FIG.

Referring to FIG. 1, the hexagonal valve 12 has a first connection port P1, a second connection port P2, a third connection port P3, a fourth connection port P4, a fifth connection port P5 and a sixth connection port. there is The first connection port P<b>1 is connected to the discharge port of the high pressure side compressor 11 . The second connection port P2 is connected to the suction port of the high pressure side compressor 11 . The third connection port P3 is connected to the high temperature side refrigerant heat exchanger 13 . The fourth connection port P4 is connected to the cascade heat exchanger 15 . The fifth connection port P5 is connected to the refrigerant inlet of the first heat medium heat exchanger 16 . The sixth connection port P6 is connected to the refrigerant outlet of the first heat medium heat exchanger 16 .

Referring to FIG. 2, the first connection port P1 and the third connection port P3 are connected to the high-pressure side of the high-pressure side refrigerant circuit 10 during cooling operation. The second connection port P2, the fourth connection port P4, the fifth connection port P5, and the sixth connection port P6 are connected to the low pressure side of the high pressure side refrigerant circuit 10. As shown in FIG.

Referring to FIG. 3, during heating operation, the first connection port P1, the fourth connection port P4, the fifth connection port P5 and the sixth connection port P6 are connected to the high side of the high side refrigerant circuit 10. there is The second connection port P2 and the third connection port P3 are connected to the low voltage side of the high voltage side refrigerant circuit 10 .

2 and 3, the first connection port P1 is always connected to the high pressure side of the high temperature side refrigerant circuit during cooling operation and heating operation. The second connection port P2 is always connected to the low pressure side of the high source side refrigerant circuit during cooling operation and heating operation.

The structure and operation of an example of the hexagonal valve 12 will be described with reference to FIGS. 4 and 5. FIG. An example of the hexagonal valve 12 is a slide switching valve. The hexagonal valve 12 has a valve body 12a and a valve body 12b. The valve body 12a is a hollow frame. The valve body 12b is configured to be able to switch the flow path in the hexagonal valve 12 by sliding in the valve main body 12a according to the pressure difference. The hexagonal valve 12 has two flow paths provided in the valve body 12b and one flow path between a connection port not connected to the two flow paths and a first connection port.

As shown in FIG. 4, during cooling operation, the first connection port P1 and the third connection port P3 are connected, the second connection port P2 and the fourth connection port P4 are connected, and the fifth connection port P5 is connected. It is connected to the sixth connection port P6.

As shown in FIG. 5, during heating operation, the first connection port P1 and the fifth connection port P5 are connected, the fourth connection port P4 and the sixth connection port P6 are connected, and the second connection port P2 is connected. The third connection port P3 is connected.

During cooling operation and heating operation, the first connection port P1 is always connected to the high-pressure side of the high-side refrigerant circuit, and the second connection port P2 is always connected to the low-pressure side of the high-side refrigerant circuit. It becomes possible to ensure a stable pressure difference.

Furthermore, with reference to FIG. 6, the second heat medium heat exchanger 25 of the refrigeration cycle apparatus 1 according to the embodiment will be described in detail.

The low-side refrigerant flowing through the second heat medium heat exchanger 25 flows from bottom to top during cooling operation, and flows from top to bottom during heating operation. Therefore, the gaseous low temperature refrigerant flows from bottom to top during cooling operation, and the liquid low temperature refrigerant flows from top to bottom during heating operation. The heat medium flowing through the second heat medium heat exchanger 25 flows from bottom to top during cooling operation and heating operation. The low temperature side refrigerant and the heat medium flowing through the second heat medium heat exchanger 25 flow in parallel during cooling operation in which the second heat medium heat exchanger 25 functions as an evaporator. It functions as a condenser and flows in opposite directions during heating operation.

Next, the effects of the refrigeration cycle device 1 according to the embodiment will be described.
According to the refrigerating cycle device 1 according to the embodiment, heat exchange is performed between the high temperature side refrigerant and the low temperature side refrigerant in the cascade heat exchanger 15 during the cooling operation. Therefore, by increasing the subcooling (the degree of supercooling), the enthalpy difference increases, which makes it possible to increase the performance. On the other hand, during heating operation, heat is exchanged between the high temperature side refrigerant and the low temperature side refrigerant in the cascade heat exchanger 15 . Therefore, in the cascade heat exchanger 15, the low-side refrigerant evaporates at an increased temperature, which makes it possible to increase the capacity. Furthermore, in the first heat medium heat exchanger 16, heat exchange is performed between the high pressure side refrigerant and the heat medium. Therefore, in the first heat medium heat exchanger 16, the heat medium can be directly heated by the high pressure side refrigerant. The heat exchange efficiency is such that heat exchange is more direct between the high temperature side refrigerant and the heat medium than when heat is exchanged between the high temperature side refrigerant and the heat medium via the cascade heat exchanger 15. Better if done. Therefore, it is possible to increase the capacity. Therefore, it is possible to increase the capacity of both cooling and heating.

In addition, the six-way valve 12 enables simplification of the high temperature side refrigerant circuit 10 . As a result, it is possible to downsize the equipment that constitutes the high-voltage side refrigerant circuit 10 . Furthermore, the cost of the high-voltage side refrigerant circuit 10 can be reduced.

According to the refrigeration cycle device 1 according to the embodiment, the high-side refrigerant is a combustible refrigerant, and the low-side refrigerant is a nonflammable refrigerant. Since the high temperature side refrigerant does not flow to the first heat medium heat exchanger 16 during cooling operation, the first heat medium heat exchanger 16 is not destroyed by freezing of the heat medium. Therefore, when the first heat medium heat exchanger 16 is destroyed, the combustible refrigerant does not flow into the room. Therefore, safety can be ensured even if the high-pressure side refrigerant is a combustible refrigerant.

In addition, since the high-side refrigerant is a flammable refrigerant such as propane, and the low-side refrigerant is carbon dioxide (CO ₂ ), for example, it is possible to comply with refrigerant regulations that regulate the use of Freon. .

According to the refrigeration cycle apparatus 1 according to the embodiment, the first connection port P1 in the hexagonal valve 12 is always connected to the high-pressure side of the high-side refrigerant circuit during cooling operation and during heating operation, and the second connection port P2 is always connected to the low pressure side of the high source side refrigerant circuit during cooling operation and heating operation. Therefore, when the flow path in the hexagonal valve 12 is switched according to the high and low pressure difference, it is possible to stably ensure the high and low pressure difference.

According to the refrigeration cycle apparatus 1 according to the embodiment, the low-side refrigerant flowing through the second heat medium heat exchanger 25 flows upward during cooling operation, and flows downward during heating operation. . Therefore, the gaseous low temperature refrigerant flows from bottom to top during cooling operation, and the liquid low temperature refrigerant flows from top to bottom during heating operation. If the gaseous low-concentration refrigerant flows downward during the cooling operation, the resistance of the low-concentration refrigerant will increase and the heat transfer efficiency will decrease. In contrast, in the refrigeration cycle apparatus 1 according to the embodiment, the gaseous low-side refrigerant flows upward from the bottom during the cooling operation, thereby suppressing a decrease in heat transfer efficiency.

It should be considered that the embodiments disclosed this time are illustrative in all respects and not restrictive. The scope of the present invention is indicated by the scope of the claims rather than the above description, and is intended to include all changes within the scope and meaning equivalent to the scope of the claims.

1 refrigeration cycle device, 10 high temperature side refrigerant circuit, 11 high temperature side compressor, 12 hexagonal valve, 13 high temperature side refrigerant heat exchanger, 14 high temperature side expansion valve, 15 cascade heat exchanger, 16 first heat medium heat exchanger 20 low-side refrigerant circuit 21 low-side compressor 22 four-way valve 23 low-side refrigerant heat exchanger 24 low-side expansion valve 25 second heat medium heat exchanger 30 heat medium Circuit, 40 control device, P1 first connection port, P2 second connection port, P3 third connection port, P4 fourth connection port, P5 fifth connection port, P6 sixth connection port.

Claims (4)

A high temperature side refrigerant that has a high temperature side compressor, a hexagonal valve, a high temperature side refrigerant heat exchanger, a high temperature side expansion valve, a cascade heat exchanger, and a first heat medium heat exchanger, and circulates the high temperature side refrigerant. a circuit;
a low gas side refrigerant circuit having a low gas side compressor, a four-way valve, the cascade heat exchanger, a low gas side expansion valve and a second heat medium heat exchanger, and circulating a low gas side refrigerant;
A heat medium circuit for circulating a heat medium through the first heat medium heat exchanger and the second heat medium heat exchanger,
During cooling operation,
The high-pressure side refrigerant circuit is composed of the high-pressure side compressor, the 6-way valve, the high-pressure side refrigerant heat exchanger, the high-pressure side expansion valve, the cascade heat exchanger, and the 6-way valve in this order. The hexagonal valve is switched so that
The low-side refrigerant circuit comprises the low-side compressor, the four-way valve, the cascade heat exchanger, the low-side expansion valve, the second heat medium heat exchanger, and the four-way valve in this order. The four-way valve is switched so that
In the second heat medium heat exchanger, heat exchange is performed between the heat medium circulating in the heat medium circuit and the low temperature side refrigerant circulating in the low temperature side refrigerant circuit,
During heating operation,
The high temperature side refrigerant circuit comprises the high temperature side compressor, the 6-way valve, the first heat medium heat exchanger, the 6-way valve, the cascade heat exchanger, the high temperature side expansion valve, and the high temperature side refrigerant heat. The hexagonal valve is switched so that the high pressure side refrigerant flows in the order of the exchanger and the hexagonal valve,
The low-side refrigerant circuit comprises the low-side compressor, the four-way valve, the second heat medium heat exchanger, the low-side expansion valve, the cascade heat exchanger, and the four-way valve in this order. The four-way valve is switched so that
In the second heat medium heat exchanger, heat exchange is performed between the heat medium circulating in the heat medium circuit and the low temperature side refrigerant circulating in the low temperature side refrigerant circuit, and the first heat medium A refrigeration cycle apparatus in which heat exchange is performed between the heat medium circulating in the heat medium circuit and the high temperature side refrigerant circulating in the high temperature side refrigerant circuit in a heat exchanger. The high-pressure side refrigerant is a flammable refrigerant,
2. The refrigeration cycle apparatus according to claim 1, wherein said low-side refrigerant is a nonflammable refrigerant. The hexagonal valve has a first connection port and a second connection port,
The first connection port is always connected to the high-pressure side of the high-side refrigerant circuit during the cooling operation and during the heating operation,
3. The refrigeration cycle apparatus according to claim 1, wherein said second connection port is always connected to the low-pressure side of said high-voltage side refrigerant circuit during said cooling operation and said heating operation. The low-side refrigerant flowing through the second heat medium heat exchanger flows from bottom to top during the cooling operation, and flows from top to bottom during the heating operation. The refrigeration cycle device according to the item.

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