Refrigeration cycle equipment

Abstract

This refrigeration cycle device comprises: a first heat medium circuit through which circulates a first heat medium having heat derived from renewable energy; a refrigerant circuit that has a compressor that compresses a first refrigerant, a first heat exchanger for performing heat exchange between the first heat medium and the first refrigerant, and a refrigerant flow path through which flows the first refrigerant of a second heat exchanger for performing heat exchange between a second heat medium and the first refrigerant; and a second heat medium circuit that is independent of the first heat medium circuit and that has a load-side heat exchanger for performing heat exchange between the second heat medium and a fluid to be heated or to be cooled, and a heat medium flow path through which the second heat medium of the second heat exchanger flows.

Description

Technical Field

[0001] The present disclosure relates to a refrigeration cycle apparatus.

Background Art

[0002] Conventionally, in refrigeration cycle apparatuses such as air conditioners, it has been proposed to utilize so-called renewable energy such as geothermal heat (for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the field of refrigeration cycle apparatuses, in recent years, regulations have been advanced globally to reduce the amount of refrigerant charged. For this reason, in a refrigeration cycle apparatus that utilizes unused heat such as in Patent Document 1, it is conceivable to configure the refrigerant to circulate only inside the heat source machine and circulate a heat medium such as water outside the heat source machine in order to reduce the amount of refrigerant charged. However, when recovering heat derived from renewable energy via a heat medium, depending on the circuit configuration, the recovered heat may be lost, and the effect of improving the energy-saving performance by utilizing renewable energy may not be sufficiently obtained.

[0005] The present disclosure has been made to solve the above problems, and an object thereof is to provide a refrigeration cycle apparatus that suppresses a decrease in energy-saving performance.

Means for Solving the Problems

[0006] The refrigeration cycle device according to this disclosure includes a first heat transfer medium circuit through which a first heat transfer medium having heat derived from renewable energy circulates, a compressor for compressing a first refrigerant, a first heat exchanger for performing heat exchange between the first heat transfer medium and the first refrigerant, and a refrigerant flow path through which the first refrigerant flows in a second heat exchanger for performing heat exchange between a second heat transfer medium and the first refrigerant. A refrigerant heat exchanger that performs heat exchange between the first refrigerant and the outdoor air, A refrigerant circuit having a refrigerant circuit having a load-side heat exchanger that is independent of the first heat transfer circuit and performs heat exchange between the second heat transfer medium and a fluid that is to be heated or cooled, and a heat transfer medium flow path through which the second heat transfer medium of the second heat exchanger flows, A heat source side blower that supplies outdoor air to a refrigerant heat exchanger, a first bypass pipe connecting the upstream and downstream sides of the refrigerant heat exchanger, a first bypass valve provided in the first bypass pipe for adjusting the flow rate of the first refrigerant, and a control device that controls the first bypass valve. Equipped with The control device opens the first bypass valve when the rotation speed of the heat source side blower is below a threshold, and closes the first bypass valve when the rotation speed of the heat source side blower is above the threshold. . [Effects of the Invention]

[0007] According to the refrigeration cycle device of this disclosure, the first heat transfer medium circuit and the second heat transfer medium circuit are independent. Therefore, mixing of the first and second heat transfer mediums and the resulting waste of heat derived from renewable energy are suppressed. Consequently, the refrigeration cycle device of this disclosure can suppress a decrease in energy-saving performance. [Brief explanation of the drawing]

[0008] [Figure 1] This is a refrigerant circuit diagram showing a refrigeration cycle device according to Embodiment 1. [Figure 2] This is a hardware configuration diagram showing the control device according to Embodiment 1. [Figure 3] This is a hardware configuration diagram showing the control device according to Embodiment 1. [Figure 4] This is a functional block diagram showing a refrigeration cycle device according to Embodiment 1. [Figure 5] This is a refrigerant circuit diagram showing a modified refrigeration cycle device according to Embodiment 1. [Figure 6] This is a refrigerant circuit diagram showing a refrigeration cycle device according to Embodiment 2. [Figure 7] This is a functional block diagram showing a refrigeration cycle device according to Embodiment 2. [Figure 8]It is a flowchart showing the operation of the control device according to Embodiment 2. [Figure 9] It is a refrigerant circuit diagram showing the refrigeration cycle device according to Embodiment 3. [Figure 10] It is a functional block diagram showing the refrigeration cycle device according to Embodiment 3. [Figure 11] It is a flowchart showing the operation of the control device according to Embodiment 3. [Figure 12] It is a refrigerant circuit diagram showing the refrigeration cycle device according to Embodiment 4. [Figure 13] It is a functional block diagram showing the refrigeration cycle device according to Embodiment 4. [Figure 14] It is a refrigerant circuit diagram showing the refrigeration cycle device according to Embodiment 5. [Figure 15] It is a functional block diagram showing the refrigeration cycle device according to Embodiment 5. [Figure 16] It is a refrigerant circuit diagram showing the flow of refrigerant and heat medium during full cooling operation and full heating operation in the refrigeration cycle device according to Embodiment 5. [Figure 17] It is a refrigerant circuit diagram showing the flow of refrigerant and heat medium during simultaneous cooling and heating operation in the refrigeration cycle device according to Embodiment 5. [Figure 18] It is a refrigerant circuit diagram showing the flow of refrigerant and heat medium during simultaneous cooling and heating operation in the refrigeration cycle device according to Embodiment 5.

Embodiments for Carrying Out the Invention

[0009] Hereinafter, embodiments will be described based on the drawings. In each figure, those with the same reference numerals are the same or corresponding ones, which is common throughout the entire specification. Also, the forms of the components shown throughout the entire specification are merely examples and are not limited to these descriptions. Furthermore, in the following drawings, the relationship of the sizes of each component may be different from the actual ones.

[0010] Embodiment 1. FIG. 1 is a refrigerant circuit diagram showing the flow of refrigerant during the cooling operation of the refrigeration cycle apparatus 1 according to Embodiment 1. The refrigeration cycle apparatus 1 of Embodiment 1 is an air conditioner that performs indoor cooling and heating. In FIG. 1, the flow of refrigerant during the cooling operation is shown by a solid line, and the flow of refrigerant during the heating operation is shown by a broken line. The refrigeration cycle apparatus 1 includes a heat source machine 2, an auxiliary heat source machine 4, and a load device 5.

[0011] Hereinafter, a case where the refrigeration cycle apparatus 1 is an air conditioner capable of executing at least a cooling operation and a heating operation as operation modes will be described as an example. However, the refrigeration cycle apparatus 1 may be a refrigerator, a freezer, or a vending machine that cools stored items. Further, the refrigeration cycle apparatus 1 may be a refrigeration device provided in a showcase or the like. Furthermore, the refrigeration cycle apparatus 1 may be a water heater that supplies hot water or a chiller that supplies cold water.

[0012] The heat source machine 2 is, for example, an outdoor unit provided outdoors. The heat source machine 2 is a device that supplies warm heat or cold heat to the load device 5. The heat source machine 2 has a compressor 21, a flow path switching device 22, a refrigerant heat exchanger 23, a heat source side blower 24, a first heat exchanger 25, a second heat exchanger 26, a main throttle device 27, a sub throttle device 28, a first heat medium pump 29, a second heat medium pump 30, and a control device 100. The compressor 21, the flow path switching device 22, the refrigerant heat exchanger 23, the first heat exchanger 25, the second heat exchanger 26, the main throttle device 27, and the sub throttle device 28 are connected by a refrigerant pipe 701 to form a refrigerant circuit 81. The refrigerant circuit 81 of Embodiment 1 corresponds to the "refrigerant circuit" of the present disclosure, and the refrigerant circulating in the refrigerant circuit 81 corresponds to the "first refrigerant" of the present disclosure.

[0013] The compressor 21 sucks in and compresses low-pressure gas refrigerant and discharges it as high-pressure gas refrigerant. As the compressor 21, for example, a compressor 21 such as a reciprocating, rotary, scroll, or screw compressor 21 is used.

[0014] The flow path switching device 22 switches between cooling operation, in which the refrigerant heat exchanger 23 functions as a condenser, and heating operation, in which the refrigerant heat exchanger 23 functions as an evaporator. The flow path switching device 22 is, for example, a four-way valve and is controlled by the control device 100. During cooling operation, the flow path switching device 22 switches the flow so that the refrigerant discharged from the compressor 21 flows into the refrigerant heat exchanger 23. During heating operation, the flow path switching device 22 switches the flow so that the refrigerant discharged from the compressor 21 flows into the second heat exchanger 26.

[0015] The refrigerant heat exchanger 23 is, for example, a fin-tube type heat exchanger, which exchanges heat between the refrigerant flowing inside the cylindrical or flattened tube and the outdoor air supplied by the heat source side blower 24. The refrigerant heat exchanger 23 functions as an evaporator during heating operation and as a condenser during cooling operation.

[0016] The heat source side blower 24 is a device that supplies outdoor air to the refrigerant heat exchanger 23. The heat source side blower 24 is positioned adjacent to the refrigerant heat exchanger 23. By supplying outdoor air from the heat source side blower 24, the efficiency of heat exchange between the refrigerant and the outdoor air is improved. A propeller fan, a line flow fan (registered trademark), or a multi-blade centrifugal fan can be used as the heat source side blower 24.

[0017] The first heat exchanger 25 is, for example, a plate heat exchanger, and performs heat exchange between the refrigerant flowing through the refrigerant piping 701 and the first heat transfer medium flowing through the first heat transfer medium piping 801, which will be described later. The first heat exchanger 25 is installed in the refrigerant piping 701 between the main throttling device 27 and the sub-throttling device 28. The first heat exchanger 25 has a refrigerant flow path 25a connected to the refrigerant piping 701 through which the refrigerant flows, and a heat transfer medium flow path 25b connected to the first heat transfer medium piping 801 through which the first heat transfer medium flows. During cooling operation, the first heat exchanger 25 functions as a condenser to condense the refrigerant, and during heating operation, it functions as an evaporator to evaporate the refrigerant.

[0018] The second heat exchanger 26 is, for example, a plate-type heat exchanger, and performs heat exchange between the refrigerant flowing through the refrigerant piping 701 and the second heat transfer medium flowing through the second heat transfer medium piping 802, which will be described later. The second heat exchanger 26 is installed in the refrigerant piping 701 between the main throttling device 27 and the flow path switching device 22. The second heat exchanger 26 has a refrigerant flow path 26a connected to the refrigerant piping 701 through which the refrigerant flows, and a heat transfer medium flow path 26b connected to the second heat transfer medium piping 802 through which the second heat transfer medium flows. During cooling operation, the second heat exchanger 26 functions as an evaporator to evaporate the refrigerant, and during heating operation, it functions as a condenser to condense the refrigerant.

[0019] The main throttling device 27 is an electronically controlled expansion valve with an adjustable opening. The main throttling device 27 is installed in the refrigerant piping 701 between the first heat exchanger 25 and the second heat exchanger 26. The main throttling device 27 depressurizes and expands the refrigerant flowing into or out of the refrigerant heat exchanger 23. The opening of the main throttling device 27 is controlled by the control device 100.

[0020] The auxiliary throttling device 28 is an electronically controlled expansion valve with an adjustable opening. The auxiliary throttling device 28 is installed in the refrigerant piping 701 between the first heat exchanger 25 and the refrigerant heat exchanger 23. The auxiliary throttling device 28 depressurizes and expands the refrigerant flowing into or out of the refrigerant heat exchanger 23. The opening of the auxiliary throttling device 28 is controlled by the control device 100.

[0021] The first heat transfer fluid pump 29 is installed in the first heat transfer fluid piping 801 and circulates the first heat transfer fluid. The first heat transfer fluid pump 29 is, for example, a capacity-controllable inverter-type centrifugal pump.

[0022] The second heat transfer fluid pump 30 is installed in the second heat transfer fluid piping 802 and circulates the second heat transfer fluid. The second heat transfer fluid pump 30 is, for example, a capacity-controllable inverter-type centrifugal pump.

[0023] The control device 100 controls each component of the refrigeration cycle device 1. Figure 2 is a hardware configuration diagram showing the control device 100 according to Embodiment 1. As shown in Figure 2, the control device 100 is dedicated hardware composed of a processing circuit 101 such as an ASIC (Application Specific Integrated Circuit) or FPGA (Field-Programmable Gate Array). Figure 3 is also a hardware configuration diagram showing the control device 100 according to Embodiment 1. When the functions of the control device 100 are executed by software, the control device 100 may be composed of a processor 102 such as a CPU and a memory 103, as shown in Figure 3. Figure 3 shows that the processor 102 and the memory 103 are connected to each other so as to be able to communicate via a bus 104. The functions of the control device 100 are realized by the processor 102 reading and executing programs stored in the memory 103. As the memory 103, a non-volatile or volatile semiconductor memory or a removable recording medium can be used. The functions of the control device 100 will be described later.

[0024] In Figure 1, the control device 100 is located on the heat source unit 2. However, the control device 100 may also be located on the auxiliary heat source unit 4 or the load device 5. Alternatively, individual control devices 100 may be provided on the heat source unit 2, the auxiliary heat source unit 4, and the load device 5, and they may communicate with each other. Furthermore, the control device 100 may be located at a location away from the heat source unit 2, the auxiliary heat source unit 4, and the load device 5.

[0025] The auxiliary heat source unit 4 is a device that supplies heat or cold to the heat source unit 2. As will be described in detail later, the auxiliary heat source unit 4 utilizes renewable energy as its heat source and performs a supplementary function to the heat source unit 2. The auxiliary heat source unit 4 has a heat transfer medium heat exchanger 41 and a third heat transfer medium pump 42.

[0026] The heat exchanger 41 is, for example, a plate heat exchanger, which performs heat exchange between a first heat exchanger and a third heat exchanger. The heat exchanger 41 has a first heat exchanger channel 41a through which the first heat exchanger flows, and a third heat exchanger channel 41b through which the third heat exchanger flows. The first heat exchanger pump 29 of the heat source unit 2, the heat exchanger channel 25b of the first heat exchanger 25, and the first heat exchanger channel 41a of the heat exchanger 41 are connected by a first heat exchanger pipe 801 through which the first heat exchanger flows, thereby forming a first heat exchanger circuit 91. For the first heat exchanger, for example, an aqueous solution of calcium chloride, an aqueous solution of sodium chloride, an aqueous solution of magnesium chloride, a brine containing ethylene glycol, antifreeze, or water can be used.

[0027] The third heat transfer medium channel 41b of the heat transfer medium heat exchanger 41 is connected to a tank 61 in which the third heat transfer medium is stored by a third heat transfer medium pipe 803. The third heat transfer medium is supplied to the third heat transfer medium channel 41b from the tank 61 via the third heat transfer medium pipe 803.

[0028] The third heat transfer fluid pump 42 is installed in the third heat transfer fluid piping 803 and circulates the third heat transfer fluid. The third heat transfer fluid pump 42 is, for example, a capacity-controllable inverter-type centrifugal pump. The third heat transfer fluid circuit 93 is formed by connecting the tank 61, the third heat transfer fluid pump 42, and the third heat transfer fluid flow path 41b of the heat transfer fluid heat exchanger 41 by the third heat transfer fluid piping 803.

[0029] It is desirable that the temperature of the third heat transfer medium circulating in the water circuit remain stable throughout the year. In particular, it is desirable that the temperature of the third heat transfer medium be lower than the outdoor air temperature during cooling operation and higher than the outdoor air temperature during heating operation. During cooling operation, the heat transfer medium heat exchanger 41 performs heat exchange between the first heat transfer medium flowing through the first heat transfer medium channel 41a and the third heat transfer medium flowing through the third heat transfer medium channel 41b, thereby cooling the first heat transfer medium. During heating operation, the heat transfer medium heat exchanger 41 performs heat exchange between the first heat transfer medium and the third heat transfer medium, thereby heating the first heat transfer medium.

[0030] The third heat transfer medium stored in tank 61 is, for example, well water. Well water contains geothermal energy, which is renewable energy found in the earth. In other words, well water is a fluid that has heat derived from geothermal energy, and the heat transfer medium heat exchanger 41 utilizes the geothermal energy contained in the well water as a heat source. Renewable energy refers to energy that is replenished by nature at a rate exceeding its utilization.

[0031] Solar heat may be used as the heat source for the heat transfer medium heat exchanger 41. When solar heat is used as the heat source for the heat transfer medium heat exchanger 41, the third heat transfer medium, heated via solar panels or the like, is stored in the tank 61. In this case, specific third heat transfer mediums that can be used include aqueous calcium chloride solution, aqueous sodium chloride solution, aqueous magnesium chloride solution, brine containing ethylene glycol, antifreeze, or water. However, instead of directly circulating well water through the heat transfer medium heat exchanger 41, a heat exchanger may be provided in the tank 61 to perform heat exchange between the third heat transfer medium (such as aqueous calcium chloride solution, aqueous sodium chloride solution, aqueous magnesium chloride solution, brine containing ethylene glycol, antifreeze, or water) and well water, and the heat-exchanged third heat transfer medium may be circulated through the third heat transfer medium circuit 93. Furthermore, as the fluid flowing through the heat transfer medium heat exchanger 41 as described above, a fluid having heat derived from renewable energy sources other than geothermal and solar heat may be used.

[0032] The load device 5 is, for example, an indoor unit installed in a room. The load device 5 receives cooling or heating from the heat source unit 2 via a refrigerant and performs air conditioning in the room. The load device 5 has a load-side heat exchanger 51 and a load-side blower 52.

[0033] The load-side heat exchanger 51 is, for example, a fin-tube type heat exchanger, and performs heat exchange between a second heat transfer medium flowing inside a circular or flat tube and indoor air supplied by the load-side blower 52. In heating operation, the load-side heat exchanger 51 cools the second heat transfer medium to heat the indoor air, and in cooling operation, it heats the second heat transfer medium to cool the indoor air. If the refrigeration cycle device 1 is, for example, a chiller, the load-side heat exchanger 51 may perform heat exchange between the second heat transfer medium and water to supply chilled water. If the refrigeration cycle device 1 is, for example, a water heater, the load-side heat exchanger 51 may perform heat exchange between the second heat transfer medium and water to supply hot water. In the load-side heat exchanger 51, the fluid with which heat exchange is performed with the refrigerant corresponds to the "fluid" in this disclosure.

[0034] When the refrigeration cycle device 1, which is an air conditioner, is operating in cooling mode, the air in the air-conditioned space where the load device 5 is installed is the "object to be cooled" in this disclosure. Similarly, when the refrigeration cycle device 1, which is a chiller, is supplying chilled water, the water flowing through the load-side heat exchanger 51 is the "object to be cooled" in this disclosure. Likewise, when the refrigeration cycle device 1, which is an air conditioner, is operating in heating mode, the air in the air-conditioned space where the load device 5 is installed is the "object to be heated" in this disclosure. Furthermore, when the refrigeration cycle device 1, which is a water heater, is supplying hot water, the water flowing through the load-side heat exchanger 51 is the "object to be heated" in this disclosure.

[0035] The second heat transfer medium circuit 92 is formed by connecting the second heat transfer medium pump 30 of the heat source unit 2, the heat transfer medium flow path 26b of the second heat exchanger 26, and the load-side heat exchanger 51 by a second heat transfer medium pipe 802 through which the second heat transfer medium flows. The second heat transfer medium can be, for example, an aqueous solution of calcium chloride, an aqueous solution of sodium chloride, an aqueous solution of magnesium chloride, brine containing ethylene glycol, antifreeze, or water. The second heat transfer medium circuit 92 is independent of the first heat transfer medium circuit 91, and the first heat transfer medium flowing through the first heat transfer medium circuit 91 does not flow into the second heat transfer medium circuit 92. Therefore, the second heat transfer medium circuit 92 is not directly affected by the thermal influence of the first heat transfer medium circuit 91.

[0036] The load-side blower 52 is a device that supplies indoor air to the load-side heat exchanger 51. The load-side blower 52 is positioned adjacent to the load-side heat exchanger 51. By supplying indoor air from the load-side blower 52, the efficiency of heat exchange between the refrigerant and the indoor air is improved. A propeller fan, a line flow fan (registered trademark), or a multi-blade centrifugal fan can be used as the load-side blower 52. If the load-side heat exchanger 51 exchanges heat between a fluid such as water and a refrigerant, a pump that circulates the water or other fluid may be used instead of the load-side blower 52.

[0037] The refrigerant temperature sensor 301 is installed in the refrigerant piping 701 between the first heat exchanger 25 and the main throttling device 27. The refrigerant temperature sensor 301 is, for example, a thermistor and measures the temperature of the refrigerant that flows into the first heat exchanger 25 during cooling operation. The indoor air temperature sensor 501 is installed in the load device 5. The indoor air temperature sensor 501 is, for example, a thermistor and measures the temperature of the air in the room where the load device 5 is installed. The refrigerant temperature sensor 301 and the indoor air temperature sensor 501 transmit the measurement results to the control device 100.

[0038] The refrigeration cycle device 1 may also be equipped with temperature sensors or pressure sensors other than the refrigerant temperature sensor 301 and the indoor air temperature sensor 501. For example, the refrigeration cycle device 1 may be equipped with a sensor that detects the temperature of the refrigerant flowing through the refrigerant heat exchanger 23, the temperature of the heat transfer medium flowing through the load-side heat exchanger 51, the temperature of the air blown out from the outlet of the load device 5, the temperature of the outdoor air, or the temperature of the well water. Alternatively, instead of the refrigerant temperature sensor 301, a refrigerant pressure sensor that measures the pressure of the refrigerant flowing out of the first heat exchanger 25 during cooling operation may be provided between the first heat exchanger 25 and the sub-throttling device 28.

[0039] Figure 4 is a functional block diagram showing a refrigeration cycle device 1 according to Embodiment 1. As shown in Figure 4, the control device 100 is wirelessly or wiredly connected to the compressor 21, flow path switching device 22, heat source side blower 24, main throttling device 27, sub-throttling device 28, first heat transfer fluid pump 29, second heat transfer fluid pump 30, third heat transfer fluid pump 42, and load side blower 52 for communication. The control device 100 controls the connection direction of the flow path switching device 22 to switch the operating mode. The control device 100 controls the rotation speed of the compressor 21, the rotation speed of the heat source side blower 24, the opening degree of the main throttling device 27, the rotation speed of the first heat transfer fluid pump 29, the rotation speed of the second heat transfer fluid pump 30, the rotation speed of the third heat transfer fluid pump 42, and the rotation speed of the load side blower 52 so that the temperature of the indoor air measured by the indoor air temperature sensor 501 becomes the temperature set by the user.

[0040] The control device 100 fully opens the sub-throttling device 28 during heating operation. During cooling operation, the control device 100 adjusts the opening of the sub-throttling device 28 to prevent the first heat transfer medium flowing through the first heat exchanger 25 from freezing. Specifically, the control device 100 reduces the opening of the sub-throttling device 28 as the temperature of the refrigerant flowing into the first heat exchanger 25, as measured by the refrigerant temperature sensor 301, decreases.

[0041] The operation of the refrigeration cycle device 1 and the flow of refrigerant will be explained. First, the cooling operation will be explained. The control device 100 performs cooling operation by switching the flow path switching device 22 so that the discharge side of the compressor 21 and the refrigerant heat exchanger 23 are connected. At this time, the refrigerant drawn into the compressor 21 is compressed and discharged in a high-temperature and high-pressure gaseous state. The high-temperature and high-pressure gaseous refrigerant discharged from the compressor 21 passes through the flow path switching device 22 and flows into the refrigerant heat exchanger 23, which acts as a condenser. The refrigerant that flows into the refrigerant heat exchanger 23 exchanges heat with the outside air supplied by the refrigerant heat exchanger 23 and condenses, becoming a high-temperature and high-pressure gas-liquid two-phase state. The high-temperature and high-pressure gas-liquid two-phase refrigerant passes through the sub-throttling device 28 and flows into the first heat exchanger 25, which acts as a condenser. The refrigerant that flows into the first heat exchanger 25 exchanges heat with the first heat transfer medium and condenses, becoming a high-pressure liquid state.

[0042] The high-pressure liquid refrigerant flows into the main throttling device 27, where it is depressurized and expanded to become a low-temperature, low-pressure gas-liquid two-phase refrigerant. The gas-liquid two-phase refrigerant flows into the second heat exchanger 26, which acts as an evaporator. The refrigerant that flows into the second heat exchanger 26 exchanges heat with the second heat transfer medium, causing the liquid phase to evaporate and become a gas. The low-temperature, low-pressure gaseous refrigerant that flows out of the second heat exchanger 26 passes through the flow path switching device 22 and flows back into the compressor 21, where it is compressed and discharged as a high-temperature, high-pressure gas.

[0043] Furthermore, the first heat transfer medium, which circulates through the first heat transfer circuit 91 by the first heat transfer pump 29, is cooled by heat exchange with the third heat transfer medium in the heat transfer heat exchanger 41. The cooled first heat transfer medium flows into the first heat exchanger 25. The first heat transfer medium that flows into the first heat exchanger 25 is heated by heat exchange with the high-temperature refrigerant. At this time, the refrigerant flowing through the first heat exchanger 25 is condensed.

[0044] Furthermore, the second heat transfer medium, circulating through the second heat transfer circuit 92 by the second heat transfer pump 30, is cooled by heat exchange with the low-temperature refrigerant in the second heat exchanger 26. During this process, the refrigerant flowing through the second heat exchanger 26 is evaporated. The cooled second heat transfer medium flows into the load-side heat exchanger 51. The low-temperature second heat transfer medium that flows into the load-side heat exchanger 51 is heated by heat exchange with the indoor air supplied by the load-side blower 52. During this process, the indoor air is cooled, and cooling is performed in the room.

[0045] Next, the heating operation will be explained. The control device 100 performs the heating operation by switching the flow path switching device 22 so that the discharge side of the compressor 21 is connected to the second heat exchanger 26. At this time, the refrigerant drawn into the compressor 21 is compressed and discharged in a high-temperature and high-pressure gaseous state. The high-temperature and high-pressure gaseous refrigerant discharged from the compressor 21 passes through the flow path switching device 22 and flows into the second heat exchanger 26, which acts as a condenser. The refrigerant that flows into the second heat exchanger 26 exchanges heat with the second heat transfer medium and condenses, becoming a low-temperature liquid state.

[0046] The refrigerant, in a low-temperature, high-pressure liquid state, is depressurized in the main throttling device 27 to become a low-temperature, low-pressure gas-liquid two-phase refrigerant. The low-temperature, low-pressure gas-liquid two-phase refrigerant flows into the first heat exchanger 25, which acts as an evaporator. The low-temperature, low-pressure gas-liquid two-phase refrigerant that flows into the first heat exchanger 25 exchanges heat with the first heat transfer medium to become a low-temperature, low-pressure gas-liquid two-phase and gaseous refrigerant. The low-temperature, low-pressure gas-liquid two-phase and gaseous refrigerant that flows out of the first heat exchanger 25 passes through the sub-throttling device 28 and flows into the refrigerant heat exchanger 23, which acts as an evaporator. The low-temperature, low-pressure gas-liquid two-phase and gaseous refrigerant that flows into the refrigerant heat exchanger 23 exchange heat with the outdoor air supplied by the refrigerant heat exchanger 23, causing the liquid phase to evaporate and becoming a low-pressure gaseous refrigerant. The low-pressure gaseous refrigerant that flows out of the refrigerant heat exchanger 23 passes through the flow path switching device 22 and flows back into the compressor 21, where it is compressed and discharged in a high-temperature, high-pressure gaseous state.

[0047] Furthermore, the first heat transfer medium, which circulates through the first heat transfer circuit 91 by the first heat transfer pump 29, is heated in the heat transfer heat exchanger 41 by exchanging heat with the third heat transfer medium. The heated first heat transfer medium flows into the first heat exchanger 25. The first heat transfer medium that flows into the first heat exchanger 25 is cooled by exchanging heat with the low-temperature refrigerant. At this time, a portion of the refrigerant flowing through the first heat exchanger 25 is evaporated.

[0048] Furthermore, the second heat transfer medium, circulating through the second heat transfer circuit 92 by the second heat transfer pump 30, is heated in the second heat exchanger 26 by exchanging heat with the high-temperature refrigerant. During this process, the refrigerant flowing through the second heat exchanger 26 is condensed. The heated second heat transfer medium flows into the load-side heat exchanger 51. The second heat transfer medium that flows into the load-side heat exchanger 51 is cooled by exchanging heat with the indoor air supplied by the load-side blower 52. During this process, the indoor air is warmed, and heating is provided in the room.

[0049] As described above, in the refrigeration cycle device 1 of Embodiment 1, the first heat transfer medium circuit 91 and the second heat transfer medium circuit 92 are independent. Therefore, mixing of the first heat transfer medium and the second heat transfer medium, and the waste of heat derived from renewable energy, is suppressed. Accordingly, the refrigeration cycle device 1 can suppress a decrease in energy saving performance.

[0050] Furthermore, by having a heat exchanger 41 that supplies heat derived from renewable energy sources such as well water to the first heat transfer medium, the rotation speed of the first heat transfer medium pump 29 can be controlled independently of the capacity of the tank 61.

[0051] (Modified version of Embodiment 1) Figure 5 is a refrigerant circuit diagram showing a modified refrigeration cycle device 1A according to Embodiment 1. As shown in Figure 5, the refrigeration cycle device 1A does not have the auxiliary heat source unit 4 having a heat transfer medium heat exchanger 41 and a third heat transfer medium pump 42 as described in Embodiment 1. In the modified embodiment of Embodiment 1, a heat transfer medium such as well water circulates through the first heat transfer medium piping 801 connected to the first heat exchanger 25. In the modified embodiment of Embodiment 1, well water corresponds to the first heat transfer medium. In the modified embodiment of Embodiment 1, the tank 61, the first heat transfer medium pump 29, and the first heat exchanger 25 are connected by the first heat transfer medium piping 801 to form the first heat transfer medium circuit 91. In the modified embodiment of Embodiment 1, the heat transfer medium heat exchanger 41 is omitted, and the thermal energy of well water, etc., can be directly supplied to the refrigerant circuit 81, thereby improving energy saving performance.

[0052] Embodiment 2. Figure 6 is a refrigerant circuit diagram showing the refrigeration cycle device 1B according to Embodiment 2. As shown in Figure 6, the refrigeration cycle device 1B of Embodiment 2 differs from the refrigeration cycle device 1 of Embodiment 1 in that it has a first bypass pipe 901 and a first bypass valve 31. In the following, we will mainly explain the differences from Embodiment 1, and omit the explanation of the common points.

[0053] The heat source unit 2A has a first bypass pipe 901 and a first bypass valve 31. The first bypass pipe 901 is a pipe that connects the upstream and downstream sides of the refrigerant heat exchanger 23. The first bypass valve 31 is an electronically controlled expansion valve installed in the first bypass pipe 901, and its opening degree is adjustable. The first bypass valve 31 adjusts the flow rate of the refrigerant flowing through the first bypass pipe 901 according to its opening degree. The opening degree of the first bypass valve 31 is controlled by the control device 100.

[0054] Figure 7 is a functional block diagram showing a refrigeration cycle device 1B according to Embodiment 2. As shown in Figure 7, the control device 100 is connected to the first bypass valve 31 via wired or wireless communication and controls the opening degree of the first bypass valve 31. The control device 100 opens the first bypass valve 31 when it determines that the heat exchange capacity of the first heat exchanger 25 is balanced with the load or is sufficiently large. Specifically, when the heat exchange capacity of the first heat exchanger 25 is balanced with the load or is sufficiently large, the discharge pressure of the compressor 21 decreases, and in response, the rotational speed of the heat source side blower 24 decreases. For this reason, the control device 100 opens the first bypass valve 31 when the rotational speed of the heat source side blower 24 is below a threshold. The opening degree at this time may be fixed, or it may be set to increase as the rotational speed of the heat source side blower 24 decreases. Also, the control device 100 closes the first bypass valve 31 when the rotational speed of the heat source side blower 24 exceeds a threshold. Furthermore, instead of the rotational speed of the heat source side blower 24, the first bypass valve 31 is opened when the discharge pressure of the compressor 21 is below a threshold.

[0055] When the first bypass valve 31 is open during cooling operation, a portion of the refrigerant discharged from the compressor 21 and flowing toward the refrigerant heat exchanger 23 flows through the first bypass piping 901. This allows the condensation temperature in the refrigerant heat exchanger 23 to be lowered. Also, when the first bypass valve 31 is open during heating operation, a portion of the refrigerant flowing out from the first heat exchanger 25 and flowing toward the refrigerant heat exchanger 23 flows through the first bypass piping 901. This allows the evaporation temperature in the refrigerant heat exchanger 23 to be increased.

[0056] Here, the method for controlling the rotational speed of the refrigerant heat exchanger 23 will be explained using Figure 8. Figure 8 is a flowchart showing the operation of the control device 100 according to Embodiment 2. First, the control device 100 determines whether the rotational speed of the heat source side blower 24 is below a threshold (step S1). If the rotational speed of the heat source side blower 24 is below the threshold (step S1: YES), the control device 100 opens the first bypass valve 31 (step S2). If the rotational speed of the heat source side blower 24 is above the threshold (step S1: NO), the control device 100 closes the first bypass valve 31 (step S3).

[0057] In the refrigeration cycle device 1B of Embodiment 2, the first heat transfer fluid circuit 91 and the second heat transfer fluid circuit 92 are independent, similar to Embodiment 1. Therefore, mixing of the first and second heat transfer fluids and the resulting waste of heat derived from renewable energy are suppressed. Consequently, the refrigeration cycle device 1B can suppress a decrease in energy-saving performance.

[0058] Furthermore, when the first bypass valve 31 is opened, the condensation temperature decreases during cooling operation and the evaporation temperature increases during heating operation. As a result, the refrigeration cycle device 1B can improve its energy-saving performance.

[0059] Embodiment 3. Figure 9 is a refrigerant circuit diagram showing the refrigeration cycle device 1C according to Embodiment 3. As shown in Figure 9, the refrigeration cycle device 1C of Embodiment 3 differs from the refrigeration cycle device 1 of Embodiment 1 in that it has a second bypass pipe 902 and a second bypass valve 32. In the following, we will mainly explain the differences from Embodiment 1, and omit the explanation of the common points.

[0060] The heat source unit 2B has a second bypass pipe 902 and a second bypass valve 32. The second bypass pipe 902 connects the upstream side of the main throttling device 27 and the downstream side of the second heat exchanger 26 in the refrigerant piping 701, based on the flow of refrigerant during cooling operation. The second bypass pipe 902 bypasses the refrigerant flowing toward the second heat exchanger 26 and the main throttling device 27. The second bypass valve 32 is an electronically controlled expansion valve provided in the second bypass pipe 902, and its opening degree is adjustable. The second bypass valve 32 adjusts the flow rate of refrigerant flowing through the second bypass pipe 902 according to its opening degree. The opening degree of the second bypass valve 32 is controlled by the control device 100.

[0061] Figure 10 is a functional block diagram showing a refrigeration cycle device 1C according to Embodiment 3. As shown in Figure 10, the control device 100 is communicated with the second bypass valve 32 by wire or wireless means and controls the opening degree of the second bypass valve 32. The control device 100 opens the second bypass valve 32 during cooling operation. At this time, the control device 100 uses a refrigerant temperature sensor 301 or the like to detect the degree of subcooling of the refrigerant at the outlet of the first heat exchanger 25 and controls the opening degree of the second bypass valve 32 so that the degree of subcooling of the refrigerant is within the target range. The target range for the degree of subcooling of the refrigerant is, for example, 3 to 15°C. If the detected degree of subcooling is greater than the target range, the control device 100 increases the opening degree of the second bypass valve 32, and if the detected degree of subcooling is less than the target range, it decreases the opening degree of the second bypass valve 32. When the second bypass valve 32 is open during cooling operation, a portion of the refrigerant flowing toward the second heat exchanger 26, which acts as an evaporator, flows through the second bypass piping 902. The control device 100 also closes the second bypass valve 32 during heating operation.

[0062] Here, the method for controlling the rotation speed of the refrigerant heat exchanger 23 will be explained using Figure 11. Figure 11 is a flowchart showing the operation of the control device 100 according to Embodiment 3. First, the control device 100 determines whether the operating mode is cooling operation or not (step S4). If the operating mode is cooling operation (step S4: YES), the control device 100 opens the second bypass valve 32 (step S5). The control device 100 controls the opening degree of the second bypass valve 32 so that the degree of subcooling of the refrigerant is within the target range. If the operating mode is heating operation (step S4: NO), the control device 100 closes the second bypass valve 32 (step S6).

[0063] In the refrigeration cycle device 1C of Embodiment 3, the first heat transfer fluid circuit 91 and the second heat transfer fluid circuit 92 are independent, similar to Embodiment 1. Therefore, mixing of the first and second heat transfer fluids and the resulting waste of heat derived from renewable energy are suppressed. Consequently, the refrigeration cycle device 1C can suppress a decrease in energy-saving performance.

[0064] Furthermore, according to Embodiment 3, during cooling operation, a portion of the refrigerant flowing toward the second heat exchanger 26, which acts as an evaporator, opens the second bypass valve 32 provided in the second bypass piping 902 so as to bypass the second heat exchanger 26. As a result, the excess refrigerant generated from the volume difference between the refrigerant heat exchanger 23 and the second heat exchanger 26 circulates through the refrigerant circuit 81 without passing through the second heat exchanger 26, which functions as an evaporator. Therefore, during cooling operation, the liquid phase ratio of the refrigerant from the downstream side of the first heat exchanger 25 to the compressor 21 is improved compared to the case where the second bypass piping 902 is not provided. As a result, the condensation temperature in the refrigerant heat exchanger 23 and the first heat exchanger 25 is reduced, and energy saving performance is improved.

[0065] Embodiment 4. Figure 12 is a refrigerant circuit diagram showing a refrigeration cycle device 1D according to Embodiment 4. As shown in Figure 12, the refrigeration cycle device 1D of Embodiment 4 has a relay unit 7, and the configuration of the heat source unit 2C differs from that of the refrigeration cycle device 1 of Embodiment 1. In the following, we will mainly explain the differences from Embodiment 1, and omit the explanation of the common points.

[0066] The heat source unit 2C does not have the first heat exchanger 25, the sub-throttling device 28, and the first heat transfer fluid pump 29 described in Embodiment 1. In Embodiment 4, the refrigerant circuit 81 is configured by connecting the compressor 21, the flow path switching device 22, the refrigerant heat exchanger 23, the main throttling device 27, and the first heat exchanger 25. The compressor 21 in the heat source unit 2C of Embodiment 4 corresponds to the "auxiliary compressor" in this disclosure. The refrigerant heat exchanger 23 in the heat source unit 2C corresponds to the "auxiliary refrigerant heat exchanger" in this disclosure. The first heat exchanger 25 in the heat source unit 2C corresponds to the "auxiliary heat transfer fluid refrigerant heat exchanger" in this disclosure. The refrigerant circuit 81 corresponds to the "auxiliary refrigerant circuit" in this disclosure, and the refrigerant circulating in the refrigerant circuit 81 corresponds to the "second refrigerant" in this disclosure.

[0067] The relay unit 7 is a device that relays the transfer of cold or hot energy between the heat source unit 2C and the auxiliary heat source unit 4 and the load device 5. The relay unit 7 has a compressor 71, a flow path switching device 72, a first heat exchanger 73, a second heat exchanger 74, a throttling device 75, and a first heat transfer medium pump 29. The compressor 71, the flow path switching device 72, the first heat exchanger 73, the throttling device 75, and the second heat exchanger 74 are connected by refrigerant piping 702 to form a refrigerant circuit 81. The refrigerant circuit 82 of Embodiment 4 corresponds to the "refrigerant circuit" of this disclosure, and the refrigerant circulating in the refrigerant circuit 82 corresponds to the "first refrigerant" of this disclosure.

[0068] The compressor 71 draws in low-pressure gaseous refrigerant, compresses it, and discharges it as high-pressure gaseous refrigerant. Examples of compressors used for the compressor 71 include reciprocating, rotary, scroll, and screw compressors.

[0069] The flow path switching device 72 switches between cooling operation, in which the first heat exchanger 73 functions as a condenser and the second heat exchanger 74 functions as an evaporator, and heating operation, in which the first heat exchanger 73 functions as an evaporator and the second heat exchanger 74 functions as a condenser. The flow path switching device 72 is, for example, a four-way valve and is controlled by the control device 100. During cooling operation, the flow path switching device 72 is switched so that the refrigerant discharged from the compressor 71 flows into the first heat exchanger 73. During heating operation, the flow path switching device 72 is switched so that the refrigerant discharged from the compressor 71 flows into the second heat exchanger 74.

[0070] The first heat exchanger 73 is, for example, a plate heat exchanger, and performs heat exchange between the refrigerant flowing through the refrigerant piping 702 and the first heat transfer medium flowing through the first heat transfer medium piping 801. The first heat exchanger 73 is installed in the refrigerant piping 702 between the throttling device 75 and the flow path switching device 72. The first heat exchanger 73 has a refrigerant flow path 73a connected to the refrigerant piping 702 through which the refrigerant flows, and a first heat transfer medium flow path 73b connected to the first heat transfer medium piping 801 through which the first heat transfer medium flows. During cooling operation, the first heat exchanger 73 functions as a condenser to condense the refrigerant, and during heating operation, it functions as an evaporator to evaporate the refrigerant.

[0071] The first heat transfer fluid pump 76 of the relay unit 7, the heat transfer fluid flow path 73b of the first heat exchanger 73, and the first heat transfer fluid flow path 41a of the heat transfer fluid heat exchanger 41 of the auxiliary heat source unit 4 are connected by a first heat transfer fluid pipe 801 through which the first heat transfer fluid flows, thereby forming the first heat transfer fluid circuit 91.

[0072] The second heat exchanger 74 is, for example, a plate-type heat exchanger, and performs heat exchange between the refrigerant flowing through the refrigerant piping 702 and the second heat transfer medium flowing through the second heat transfer medium piping 802. The second heat exchanger 74 is installed in the refrigerant piping 702 between the throttling device 75 and the flow path switching device 72. The second heat exchanger 74 has a refrigerant flow path 74a connected to the refrigerant piping 702 through which the refrigerant flows, and a second heat transfer medium flow path 74b connected to the second heat transfer medium piping 802 through which the second heat transfer medium flows. During cooling operation, the second heat exchanger 74 functions as an evaporator to evaporate the refrigerant, and during heating operation, it functions as a condenser to condense the refrigerant.

[0073] The second heat transfer fluid pump 30 of the heat source unit 2C, the heat transfer fluid flow path 26b of the second heat exchanger 26, the heat transfer fluid flow path 74b of the second heat exchanger 74 of the relay unit 7, and the load-side heat exchanger 51 of the load device 5 are connected by a second heat transfer fluid pipe 802 through which the second heat transfer fluid flows, thereby forming a second heat transfer fluid circuit 92. In Embodiment 4 as well, the second heat transfer fluid circuit 92 is independent of the first heat transfer fluid circuit 91, and the first heat transfer fluid flowing through the first heat transfer fluid circuit 91 does not flow into the second heat transfer fluid circuit 92. For this reason, the second heat transfer fluid circuit 92 is not directly affected by the thermal influence of the first heat transfer fluid circuit 91.

[0074] The throttling device 75 is an electronically controlled expansion valve with an adjustable opening. The throttling device 75 is installed in the refrigerant piping 702 between the first heat exchanger 73 and the second heat exchanger 74. The throttling device 75 depressurizes and expands the refrigerant flowing into or out of the first heat exchanger 73. The opening of the main throttling device 27 is controlled by the control device 100.

[0075] The first heat transfer fluid pump 76 is installed in the first heat transfer fluid piping 801 and circulates the first heat transfer fluid. The first heat transfer fluid pump 76 is, for example, a capacity-controllable inverter-type centrifugal pump.

[0076] The refrigeration cycle device 1 has a heat transfer medium temperature sensor 401. The heat transfer medium temperature sensor 401 is located upstream of the heat transfer medium heat exchanger 41 in the heat transfer medium piping 601. The heat transfer medium temperature sensor 401 is, for example, a thermistor and measures the temperature of the heat transfer medium flowing into the heat transfer medium heat exchanger 41. The heat transfer medium temperature sensor 401 transmits the measurement result to the control device 100.

[0077] Figure 13 is a functional block diagram showing a refrigeration cycle device 1D according to Embodiment 4. As shown in Figure 13, the control device 100 is wirelessly or wiredly connected to the compressor 21, flow path switching device 22, heat source side blower 24, main throttling device 27, second heat transfer fluid pump 30, third heat transfer fluid pump 42, load side blower 52, compressor 71, flow path switching device 72, throttling device 75, and first heat transfer fluid pump 76 for communication. The control device 100 controls the connection direction of the flow path switching device 22 and the flow path switching device 72 to switch the operating mode. The control device 100 controls the rotational speed of the compressor 21, the rotational speed of the heat source side blower 24, the opening degree of the main throttling device 27, the rotational speed of the second heat transfer fluid pump 30, the rotational speed of the third heat transfer fluid pump 42, the rotational speed of the load side blower 52, the rotational speed of the compressor 71, the opening degree of the throttling device 75, and the rotational speed of the first heat transfer fluid pump 76 so that the temperature of the indoor air measured by the indoor air temperature sensor 501 becomes the temperature set by the user.

[0078] The control device 100 prioritizes the operation of the compressor 71 of the relay unit 7 over the compressor 21 of the heat source unit 2C. If the refrigerant circuit 82 of the relay unit 7 can supply sufficient heat to the load device 5, the control device 100 stops the compressor 21 of the heat source unit 2C. For example, during cooling operation, if the temperature of the heat medium measured by the heat medium temperature sensor 401 is below a first threshold, the control device 100 stops the compressor 21 of the heat source unit 2C and drives only the compressor 71 of the relay unit 7. If the temperature of the heat medium exceeds the first threshold, the control device 100 drives both the compressor 21 of the heat source unit 2C and the compressor 71 of the relay unit 7. Also, during heating operation, if the temperature of the heat medium measured by the heat medium temperature sensor 401 is above a second threshold, the control device 100 stops the compressor 21 of the heat source unit 2C and drives only the compressor 71 of the relay unit 7. When the temperature of the heat transfer medium is below the second threshold, the compressor 21 of the heat source unit 2C and the compressor 71 of the relay unit 7 are driven. The first threshold is set so that, during cooling operation, the cooling supplied to the refrigerant circuit 81 and the second heat transfer medium circuit 92 of the relay unit 7 is sufficient to handle the indoor load. The second threshold is set so that, during heating operation, the heating supplied to the refrigerant circuit 81 and the second heat transfer medium circuit 92 of the relay unit 7 is sufficient to handle the indoor load.

[0079] The operation of the refrigeration cycle unit 1D and the flow of refrigerant will be explained. Here, we will explain the case where both the compressor 21 of the relay unit 7 and the compressor 21 of the heat source unit 2C are driven. First, the cooling operation will be explained. The control device 100 performs cooling operation by switching the flow path switching device 22 so that the discharge side of the compressor 21 of the heat source unit 2C is connected to the refrigerant heat exchanger 23, and by switching the flow path switching device 72 so that the discharge side of the compressor 71 of the relay unit 7 is connected to the first heat exchanger 73. At this time, in the refrigerant circuit 81 of the heat source unit 2C, the refrigerant drawn into the compressor 21 is compressed and discharged in a high-temperature and high-pressure gaseous state. The high-temperature and high-pressure gaseous refrigerant discharged from the compressor 21 passes through the flow path switching device 22 and flows into the refrigerant heat exchanger 23, which acts as a condenser. The refrigerant that flows into the refrigerant heat exchanger 23 exchanges heat with the outdoor air sent by the refrigerant heat exchanger 23 and condenses, becoming a high-temperature and high-pressure liquid state.

[0080] The high-temperature, high-pressure liquid refrigerant flows into the main throttling device 27, where it is depressurized and expanded to become a low-temperature, low-pressure gas-liquid two-phase refrigerant. The gas-liquid two-phase refrigerant flows into the second heat exchanger 26, which acts as an evaporator. The refrigerant that flows into the second heat exchanger 26 exchanges heat with the second heat transfer medium, causing the liquid phase to evaporate and become a gas. The low-temperature, low-pressure gaseous refrigerant that flows out of the second heat exchanger 26 passes through the flow path switching device 22 and flows back into the compressor 21, where it is compressed and discharged as a high-temperature, high-pressure gas.

[0081] Furthermore, in the refrigerant circuit 82 of the relay unit 7, the refrigerant drawn into the compressor 71 is compressed and discharged in a high-temperature, high-pressure gaseous state. The high-temperature, high-pressure gaseous refrigerant discharged from the compressor 71 passes through the flow path switching device 72 and flows into the first heat exchanger 73, which acts as a condenser. The refrigerant that flows into the first heat exchanger 73 exchanges heat with the first heat transfer medium and condenses, becoming a high-temperature, high-pressure liquid state.

[0082] The high-temperature, high-pressure liquid refrigerant flows into the throttling device 75, where it is depressurized and expanded to become a low-temperature, low-pressure gas-liquid two-phase refrigerant. The gas-liquid two-phase refrigerant flows into the second heat exchanger 74, which acts as an evaporator. The refrigerant that flows into the second heat exchanger 74 exchanges heat with the second heat transfer medium, causing the liquid phase to evaporate and become a gas. The low-temperature, low-pressure gaseous refrigerant that flows out of the second heat exchanger 74 passes through the flow path switching device 72 and flows back into the compressor 71, where it is compressed and discharged as a high-temperature, high-pressure gas.

[0083] Furthermore, the first heat transfer medium, which circulates through the first heat transfer circuit 91 by the first heat transfer pump 76, is cooled by heat exchange with the third heat transfer medium in the heat transfer heat exchanger 41. The cooled first heat transfer medium flows into the first heat exchanger 73. The first heat transfer medium that flows into the first heat exchanger 73 is heated by heat exchange with the high-temperature refrigerant. At this time, the refrigerant flowing through the first heat exchanger 73 is condensed.

[0084] Furthermore, the second heat transfer medium, circulating through the second heat transfer circuit 92 by the second heat transfer pump 30, is cooled by heat exchange with the low-temperature refrigerant in the second heat exchanger 74 of the relay unit 7. The cooled second heat transfer medium is further cooled by heat exchange with the low-temperature refrigerant in the second heat exchanger 26 of the heat source unit 2C. The second heat transfer medium, cooled in two stages, flows into the load-side heat exchanger 51. The low-temperature second heat transfer medium that flows into the load-side heat exchanger 51 is heated by heat exchange with the indoor air supplied by the load-side blower 52. At this time, the indoor air is cooled, and cooling is performed in the room.

[0085] Next, the heating operation will be explained. The control device 100 performs the heating operation by switching the flow path switching device 22 so that the discharge side of the compressor 21 of the heat source unit 2C is connected to the second heat exchanger 26, and by switching the flow path switching device 72 so that the discharge side of the compressor 71 of the relay unit 7 is connected to the second heat exchanger 74. At this time, in the refrigerant circuit 81 of the heat source unit 2C, the refrigerant drawn into the compressor 21 is compressed and discharged in a high-temperature and high-pressure gaseous state. The high-temperature and high-pressure gaseous refrigerant discharged from the compressor 21 passes through the flow path switching device 22 and flows into the second heat exchanger 26, which acts as a condenser. The refrigerant that flows into the second heat exchanger 26 exchanges heat with the second heat transfer medium and condenses, becoming a low-temperature and low-pressure liquid state.

[0086] The refrigerant, in a low-temperature, low-pressure liquid state, is depressurized in the main throttling device 27 to become a low-temperature, low-pressure gas-liquid two-phase refrigerant. The low-temperature, low-pressure gas-liquid two-phase refrigerant that flows out of the main throttling device 27 flows into the refrigerant heat exchanger 23, which acts as an evaporator. The low-temperature, low-pressure gas-liquid two-phase refrigerant that flows into the refrigerant heat exchanger 23 exchanges heat with the outside air supplied by the refrigerant heat exchanger 23, causing the liquid phase to evaporate and become a low-pressure gaseous refrigerant. The low-pressure gaseous refrigerant that flows out of the refrigerant heat exchanger 23 passes through the flow path switching device 22 and flows back into the compressor 21, where it is compressed and discharged as a high-temperature, high-pressure gas.

[0087] Furthermore, in the refrigerant circuit 82 of the relay unit 7, the refrigerant drawn into the compressor 71 is compressed and discharged in a high-temperature, high-pressure gaseous state. The high-temperature, high-pressure gaseous refrigerant discharged from the compressor 71 passes through the flow path switching device 72 and flows into the second heat exchanger 74, which acts as a condenser. The refrigerant that flows into the second heat exchanger 74 exchanges heat with the second heat transfer medium and condenses, becoming a high-temperature, high-pressure liquid state.

[0088] The high-temperature, high-pressure liquid refrigerant flows into the throttling device 75, where it is depressurized and expanded to become a low-temperature, low-pressure gas-liquid two-phase refrigerant. The gas-liquid two-phase refrigerant flows into the first heat exchanger 73, which acts as an evaporator. The refrigerant that flows into the first heat exchanger 73 exchanges heat with the first heat transfer medium, causing the liquid phase to evaporate and become a gas. The low-temperature, low-pressure gaseous refrigerant that flows out of the first heat exchanger 73 passes through the flow path switching device 72 and flows back into the compressor 71, where it is compressed and discharged as a high-temperature, high-pressure gas.

[0089] Furthermore, the first heat transfer medium, which circulates through the first heat transfer circuit 91 by the first heat transfer pump 76, is heated in the heat transfer heat exchanger 41 by exchanging heat with the third heat transfer medium. The heated first heat transfer medium flows into the first heat exchanger 73. The first heat transfer medium that flows into the first heat exchanger 73 is cooled by exchanging heat with the low-temperature refrigerant. At this time, the refrigerant flowing through the first heat exchanger 73 is evaporated.

[0090] Furthermore, the second heat transfer medium, circulating through the second heat transfer circuit 92 by the second heat transfer pump 30, is heated by heat exchange with the high-temperature refrigerant in the second heat exchanger 74 of the relay unit 7. The heated second heat transfer medium is further heated by heat exchange with the high-temperature refrigerant in the second heat exchanger 26 of the heat source unit 2C. The second heat transfer medium, heated in two stages, flows into the load-side heat exchanger 51. The second heat transfer medium that flows into the load-side heat exchanger 51 is cooled by heat exchange with the indoor air supplied by the load-side blower 52. At this time, the indoor air is warmed, and heating is performed in the room.

[0091] As described above, in the refrigeration cycle device 1D of Embodiment 4, the first heat transfer medium circuit 91 and the second heat transfer medium circuit 92 are independent, similar to Embodiment 1. Therefore, mixing of the first and second heat transfer mediums and the resulting waste of heat derived from renewable energy are suppressed. Consequently, the refrigeration cycle device 1D can suppress a decrease in energy-saving performance.

[0092] Furthermore, according to Embodiment 4, since the refrigeration cycle device 1D has a refrigerant circuit 81 and a refrigerant circuit 82, the temperature of the cold supplied to the load device 5 can be lowered. Also, the temperature of the hot air supplied to the load device 5 can be increased.

[0093] Furthermore, considering the case where a similar amount of cooling or heating is supplied to the load device 5, the compressor 71 of the relay unit 7, which receives cooling or heating from the auxiliary heat source unit 4, has a lower rotational speed compared to the compressor 21 of the heat source unit 2C. Therefore, by prioritizing the use of the refrigerant circuit 82 of the relay unit 7 over the refrigerant circuit 81 of the heat source unit 2C, energy-saving performance can be improved.

[0094] Embodiment 5. Figure 14 is a refrigerant circuit diagram showing a refrigeration cycle device 1E according to Embodiment 5. As shown in Figure 14, the refrigeration cycle device 1E of Embodiment 5 differs from the refrigeration cycle device 1E of Embodiment 1 in that it has a relay unit 7 and a plurality of load devices 5a and 5b, and performs simultaneous cooling and heating operation. Simultaneous cooling and heating operation means that one of the load devices 5a and 5b performs cooling operation while the other performs heating operation. In the following, the differences from Embodiment 1 will be explained in detail, and the explanation of the common points will be omitted.

[0095] Load devices 5a and 5b are, for example, indoor units installed in a room. Load devices 5a and 5b receive cooling or heating from the heat source unit 2 via a refrigerant and perform air conditioning in the room. Load device 5a has a load-side heat exchanger 51a, a load-side fan 52a, and an outdoor air temperature sensor 501a. Load device 5b has a load-side heat exchanger 51b, a load-side fan 52b, and an outdoor air temperature sensor 501b. Load devices 5a and 5b, and the equipment they have, are all the same as load device 5 described in Embodiment 1. Therefore, a detailed explanation of load devices 5a and 5b will be omitted. Note that when load devices 5a and 5b, and the equipment they have, are not distinguished, the subscripts "a" and "b" will be omitted in the explanation.

[0096] The refrigeration cycle device 1E has a first supply pipe 804, a first return pipe 805, a second supply pipe 806, and a second return pipe 807. The first supply pipe 804 is a pipe in which one end is connected to the heat transfer medium flow path 25b of the first heat exchanger 25, and the other end branches into three directions and connects to the load-side heat exchanger 51 and the heat transfer medium heat exchanger 41. Heat transfer medium flows through the first supply pipe 804 from the first heat exchanger 25 towards the load-side heat exchanger 51 and the heat transfer medium heat exchanger 41. The first return pipe 805 is a pipe in which one end branches into three directions and connects to the load-side heat exchanger 51 and the heat transfer medium heat exchanger 41, and the other end is connected to the heat transfer medium flow path 25b of the first heat exchanger 25. Heat transfer medium flows through the first return pipe 805 from the load-side heat exchanger 51 and the heat transfer medium heat exchanger 41 towards the first heat exchanger 25.

[0097] The second supply pipe 806 has one end connected to the heat transfer medium flow path 26b of the second heat exchanger 26, and the other end branches into three directions, connecting to the respective branch sections of the first supply pipe 804 corresponding to the load-side heat exchanger 51 and the heat transfer medium heat exchanger 41. Heat transfer medium flows through the second supply pipe 806 from the second heat exchanger 26 towards the load-side heat exchanger 51 and the heat transfer medium heat exchanger 41. The second return pipe 807 has one end branching into three directions, connecting to the respective branch sections of the first return pipe 805 corresponding to the load-side heat exchanger 51 and the heat transfer medium heat exchanger 41, and the other end connected to the heat transfer medium flow path 26b of the second heat exchanger 26. Heat transfer medium flows through the second return pipe 807 from the load-side heat exchanger 51 and the heat transfer medium heat exchanger 41 towards the second heat exchanger 26.

[0098] The first heat transfer fluid pump 29 is installed in the first return pipe 805 and circulates the heat transfer fluid. The second heat transfer fluid pump 30 is installed in the second return pipe 807 and circulates the heat transfer fluid.

[0099] As described above, the first heat exchanger 25, the first heat transfer pump 29, the second heat transfer pump 30, the second heat exchanger 26, the load-side heat exchanger 51, and the heat transfer heat exchanger 41 are connected by the first supply pipe 804, the first return pipe 805, the second supply pipe 806, and the second return pipe 807. The heat transfer medium circulates through these. As the heat transfer medium, calcium chloride aqueous solution, sodium chloride aqueous solution, magnesium chloride aqueous solution, brine containing ethylene glycol, antifreeze, or water can be used. However, by providing on-off valves, which will be described later, in the first supply pipe 804, the first return pipe 805, the second supply pipe 806, and the second return pipe 807, multiple independent heat transfer medium circuits are formed so that the heat transfer medium does not circulate between the load device 5 and the auxiliary heat source machine 4, which are in different temperature zones.

[0100] The relay unit 7 is a device for distributing the heat transfer medium to the load device 5 and the auxiliary heat source device 4. The relay unit 7 has first on-off valves 201a to 201c, second on-off valves 202a to 202c, third on-off valves 203a to 203c, and fourth on-off valves 204a to 204c. When the on-off valves are not distinguished, they are referred to as on-off valve 200.

[0101] The first on-off valve 201a is located upstream of the point where the other end of the second on-off valve 806 is connected, in the branch portion of the first supply pipe 804 corresponding to the load-side heat exchanger 51a. The first on-off valve 201a is a valve that can be selectively switched by the control device 100 between an open state that allows the flow of the heat transfer medium from the first heat exchanger 25 toward the load-side heat exchanger 51a, and a closed state that blocks the flow of the heat transfer medium.

[0102] The first on-off valve 201b is located upstream of the point where the other end of the second on-off valve 806 is connected, in the branch portion of the first supply pipe 804 corresponding to the load-side heat exchanger 51b. The first on-off valve 201b is a valve that can be selectively switched by the control device 100 between an open state that allows the flow of the heat transfer medium from the first heat exchanger 25 toward the load-side heat exchanger 51b, and a closed state that blocks the flow of the heat transfer medium.

[0103] The first on-off valve 201c is located upstream of the point where the other end of the second on-off valve 806 is connected to the branch portion of the first supply pipe 804 corresponding to the heat transfer medium heat exchanger 41. The first on-off valve 201c is a valve that can be selectively switched by the control device 100 between an open state that allows the flow of the heat transfer medium from the first heat exchanger 25 toward the heat transfer medium heat exchanger 41, and a closed state that blocks the flow of the heat transfer medium.

[0104] The second on-off valve 202a is located downstream of the point where one end of the second return pipe 807 is connected, in the branch portion of the first return pipe 805 corresponding to the load-side heat exchanger 51a. The second on-off valve 202a is a valve that can be selectively switched by the control device 100 between an open state that allows the flow of the heat transfer medium from the load-side heat exchanger 51a toward the first heat exchanger 25, and a closed state that blocks the flow of the heat transfer medium.

[0105] The second on-off valve 202b is located downstream of the point where one end of the second return pipe 807 is connected, in the branch portion of the first return pipe 805 corresponding to the load-side heat exchanger 51. The second on-off valve 202b is a valve that can be selectively switched by the control device 100 between an open state that allows the flow of the heat transfer medium from the load-side heat exchanger 51b toward the first heat exchanger 25, and a closed state that blocks the flow of the heat transfer medium.

[0106] The second on-off valve 202c is located downstream of the point where one end of the second return pipe 807 is connected, in the branch portion of the first return pipe 805 corresponding to the heat transfer medium heat exchanger 41. The second on-off valve 202c is a valve that can be selectively switched by the control device 100 between an open state that allows the flow of the heat transfer medium from the heat transfer medium heat exchanger 41 toward the first heat exchanger 25, and a closed state that blocks the flow of the heat transfer medium.

[0107] The third on-off valve 203a is provided in the branch portion of the second supply pipe 806 corresponding to the load-side heat exchanger 51a. The third on-off valve 203a is a valve that can be selectively switched by the control device 100 between an open state that allows the flow of the heat transfer medium from the second heat exchanger 26 toward the load-side heat exchanger 51a, and a closed state that blocks the flow of the heat transfer medium.

[0108] The third on-off valve 203b is provided at the branching portion of the second supply pipe 806 corresponding to the load-side heat exchanger 51b. The third on-off valve 203b is a valve that can be selectively switched by the control device 100 between an open state that allows the flow of the heat transfer medium from the second heat exchanger 26 toward the load-side heat exchanger 51b and a closed state that blocks the flow of the heat transfer medium.

[0109] The third on-off valve 203c is provided in the branch portion of the second supply pipe 806 corresponding to the heat transfer medium heat exchanger 41. The third on-off valve 203c is a valve that can be selectively switched by the control device 100 between an open state that allows the flow of the heat transfer medium from the second heat exchanger 26 to the heat transfer medium heat exchanger 41, and a closed state that blocks the flow of the heat transfer medium.

[0110] The fourth on-off valve 204a is provided in the branch portion of the second return pipe 807 corresponding to the load-side heat exchanger 51a. The fourth on-off valve 204a is a valve that can be selectively switched by the control device 100 between an open state that allows the flow of the heat transfer medium from the load-side heat exchanger 51a toward the second heat exchanger 26, and a closed state that blocks the flow of the heat transfer medium.

[0111] The fourth on-off valve 204b is provided in the branch portion of the second return pipe 807 corresponding to the load-side heat exchanger 51b. The fourth on-off valve 204b is a valve that can be selectively switched by the control device 100 between an open state that allows the flow of the heat transfer medium from the load-side heat exchanger 51b toward the second heat exchanger 26, and a closed state that blocks the flow of the heat transfer medium.

[0112] The fourth on-off valve 204c is provided in the branch portion of the second return pipe 807 corresponding to the heat transfer medium heat exchanger 41. The fourth on-off valve 204c is a valve that can be selectively switched by the control device 100 between an open state that allows the flow of the heat transfer medium from the heat transfer medium heat exchanger 41 toward the second heat exchanger 26, and a closed state that blocks the flow of the heat transfer medium.

[0113] Figure 15 is a functional block diagram showing a refrigeration cycle device 1E according to Embodiment 1. As shown in Figure 15, the control device 100 is wirelessly or wiredly connected to the on-off valve 200 for communication. Below, the control of the flow path switching device 22 and the on-off valve 200 will be described for all-out cooling operation when all load devices 5 are in cooling operation, all-out heating operation when all load devices 5 are in heating operation, and simultaneous cooling and heating operation.

[0114] First, the control of the flow path switching device 22 and the on-off valve 200 during full cooling operation and full heating operation will be explained. The control device 100 switches the direction of the flow path switching device 22 so that the discharge side of the compressor 71 is connected to the refrigerant heat exchanger 23 during full cooling operation, and so that the discharge side of the compressor 71 is connected to the second heat exchanger 26 during full heating operation.

[0115] Furthermore, in both full cooling and full heating operation, the control device 100 closes the first on-off valves 201a and 201b, and the second on-off valves 202a and 202b, which correspond to the load devices 5a and 5b, and opens the third on-off valves 203a and 203b, and the fourth on-off valves 204a and 204b. This blocks the flow of the heat transfer medium between the load-side heat exchanger 51 and the first heat exchanger 25, while allowing the flow of the heat transfer medium between the load-side heat exchanger 51 and the second heat exchanger 26. In addition, the control device 100 opens the first on-off valve 201c and the second on-off valve 202c, which correspond to the auxiliary heat source unit 4, and closes the third on-off valve 203c and the fourth on-off valve 204c. This allows the flow of the heat transfer medium between the heat transfer medium heat exchanger 41 and the first heat exchanger 25, while blocking the flow of the heat transfer medium between the load-side heat exchanger 51 and the second heat exchanger 26.

[0116] Figure 16 is a refrigerant circuit diagram showing the flow of refrigerant and heat transfer medium during full cooling and full heating operations in the refrigeration cycle device 1E according to Embodiment 5. In Figure 16, pipes through which the heat transfer medium passes are shown with thick lines, and pipes through which the heat transfer medium does not pass are shown with thin lines. By controlling the open / closed state of the on / off valve 200 as described above, a heat transfer medium circuit 91A is formed in which the heat transfer medium circulates between the first heat exchanger 25 and the heat transfer medium heat exchanger 41, as shown in Figure 16. In addition, a heat transfer medium circuit 92A is formed in which the heat transfer medium circulates between the second heat exchanger 26, the load-side heat exchanger 51a, and the load-side heat exchanger 51b. The former heat transfer medium circuit 91A is a heat transfer medium circuit in which a heat transfer medium having heat derived from renewable energy that has been heat-exchanged by the heat transfer medium heat exchanger 41 circulates. Therefore, the former heat transfer medium circuit 91A corresponds to the "first heat transfer medium circuit" of this disclosure. The heat transfer medium flowing through the heat transfer medium circuit 91A is referred to as the first heat transfer medium. Furthermore, the latter heat transfer medium circuit 92A has a load-side heat exchanger 51a that performs heat exchange between the second heat transfer medium and the fluid, and a heat transfer medium flow path 26b of the second heat exchanger 26, and the first heat transfer medium that flows through the heat transfer medium circuit 91A does not flow into the heat transfer medium circuit 92A. For this reason, the heat transfer medium circuit 92A is an independent circuit that is not directly affected by the heat transfer medium circuit 91A. Thus, the latter heat transfer medium circuit 92A corresponds to the "second heat transfer medium circuit" in this disclosure. The heat transfer medium that flows through the heat transfer medium circuit 92A is referred to as the second heat transfer medium.

[0117] When the load devices 5a and 5b constituting the second heat transfer circuit are operating in cooling mode, the first heat exchanger 25 acts as a condenser to condense the refrigerant, and the second heat exchanger 26 acts as an evaporator to evaporate the refrigerant. When the load devices 5a and 5b constituting the second heat transfer circuit are operating in heating mode, the first heat exchanger 25 acts as an evaporator to evaporate the first refrigerant, and the second heat exchanger 26 acts as a condenser to condense the refrigerant.

[0118] Next, the control of the flow path switching device 22 and the on-off valve 200 during simultaneous cooling and heating operation will be explained. Here, we will explain using the example of simultaneous cooling and heating operation in which the temperature of the third heat medium circulating in the water circuit of the heat medium heat exchanger 41 is lower than the temperature of the outdoor air, and cooling operation is performed in load device 5a and heating operation is performed in load device 5b. The control device 100 switches the flow path switching device 72 to the same direction as in full cooling operation, that is, the direction in which the discharge side of the compressor 71 and the refrigerant heat exchanger 23 are connected. At this time, the heat medium heat exchanger 41 performs heat exchange between the heat medium flowing in the first heat medium flow path 41a and the third heat medium flowing in the third heat medium flow path 41b, and cools the first heat medium. The first heat exchanger 25 functions as a condenser that condenses the refrigerant with the low temperature first heat medium cooled by the third heat medium flowing in the third heat medium flow path 41b. The second heat exchanger 26 acts as an evaporator that evaporates the refrigerant.

[0119] Furthermore, the control device 100 closes the first on-off valve 201a and the second on-off valve 202a, which correspond to the load device 5a, and opens the third on-off valve 203a and the fourth on-off valve 204a. This blocks the flow of the heat transfer medium between the load-side heat exchanger 51a and the first heat exchanger 25, while allowing the flow of the heat transfer medium between the load-side heat exchanger 51a and the second heat exchanger 26. Also, the control device 100 opens the first on-off valve 201b and the second on-off valve 202b, which correspond to the load device 5b, and closes the third on-off valve 203b and the fourth on-off valve 204b. This allows the flow of the heat transfer medium between the load-side heat exchanger 51b and the first heat exchanger 25, while blocking the flow of the heat transfer medium between the load-side heat exchanger 51 and the second heat exchanger 26. Furthermore, the control device 100 opens the first on-off valve 201c and the second on-off valve 202c, which correspond to the auxiliary heat source unit 4, and closes the third on-off valve 203c and the fourth on-off valve 204c. This allows the flow of the heat transfer medium between the heat transfer medium heat exchanger 41 and the first heat exchanger 25, while blocking the flow of the heat transfer medium between the load-side heat exchanger 51 and the second heat exchanger 26.

[0120] Figure 17 is a refrigerant circuit diagram showing the flow of refrigerant and heat transfer medium during simultaneous cooling and heating operation in a refrigeration cycle device 1E according to Embodiment 5. In Figure 17, pipes through which the heat transfer medium passes are shown with thick lines, and pipes through which the heat transfer medium does not pass are shown with thin lines. By controlling the open / closed state of the on / off valve 200 as described above, a heat transfer medium circuit 91B is formed in which the heat transfer medium circulates between the first heat exchanger 25, the heat transfer medium heat exchanger 41, and the load-side heat exchanger 51b, as shown in Figure 17. In addition, a heat transfer medium circuit 92B is formed in which the heat transfer medium circulates between the second heat exchanger 26 and the load-side heat exchanger 51a. The former heat transfer medium circuit 91B is a heat transfer medium circuit in which a heat transfer medium having heat derived from renewable energy that has been heat-exchanged by the heat transfer medium heat exchanger 41 circulates. Therefore, the former heat transfer medium circuit 91B corresponds to the "first heat transfer medium circuit" of this disclosure. The heat transfer medium flowing through the former heat transfer medium circuit is referred to as the first heat transfer medium. Furthermore, the latter heat transfer medium circuit 92B has a load-side heat exchanger 51a that performs heat exchange between the second heat transfer medium and the fluid, and a heat transfer medium flow path 26b of the second heat exchanger 26, and the first heat transfer medium that flows through the heat transfer medium circuit 91B does not flow into the heat transfer medium circuit 92B. For this reason, the heat transfer medium circuit 92B is an independent circuit that is not directly affected by the heat transfer medium circuit 91B. Thus, the heat transfer medium circuit 92B corresponds to the "second heat transfer medium circuit" in this disclosure. The heat transfer medium that flows through the latter heat transfer medium circuit is referred to as the second heat transfer medium.

[0121] Thus, in Embodiment 5, the control of the on-off valve 200 is changed depending on whether the operating state of the refrigeration cycle device 1E is full cooling operation, full heating operation, or simultaneous cooling and heating operation. The combination of the on-off state of the on-off valve 200 determines which heat exchanger and piping heat transfer medium circuit will function as the "first heat transfer medium circuit" or the "second heat transfer medium circuit".

[0122] The operation of the refrigeration cycle device 1E and the flow of the refrigerant and heat transfer medium will be described. For full cooling operation and full heating operation, the only difference from Embodiment 1 is that the second heat transfer medium branches and flows to each of the load devices 5, as shown in Figure 15, so the explanation will be omitted. For this reason, only the case of simultaneous cooling and heating operation will be explained below using Figure 17. Here, the simultaneous cooling and heating operation will be explained as an example when the temperature of the third heat transfer medium circulating in the water circuit of the heat transfer medium heat exchanger 41 is lower than the temperature of the outdoor air, and when cooling operation is performed in load device 5a and heating operation is performed in load device 5b. The control device 100 switches the flow path switching device 72 to the same direction as in full cooling operation, that is, the direction in which the discharge side of the compressor 71 and the refrigerant heat exchanger 23 are connected. At this time, the refrigerant drawn into the compressor 71 is compressed and discharged in a high-temperature and high-pressure gaseous state. The high-temperature and high-pressure gaseous refrigerant discharged from the compressor 71 passes through the flow path switching device 72 and flows into the refrigerant heat exchanger 23, which acts as a condenser. The refrigerant flowing into the refrigerant heat exchanger 23 exchanges heat with the outdoor air supplied by the refrigerant heat exchanger 23 and condenses, becoming a high-temperature, high-pressure gas-liquid two-phase state. The high-temperature, high-pressure gas-liquid two-phase refrigerant passes through the sub-throttling device 28 and flows into the first heat exchanger 25, which acts as a condenser. The refrigerant flowing into the first heat exchanger 25 exchanges heat with the first heat transfer medium and condenses, becoming a high-pressure liquid state.

[0123] The high-pressure liquid refrigerant flows into the main throttling device 27, where it is depressurized and expanded to become a low-temperature, low-pressure gas-liquid two-phase refrigerant. The gas-liquid two-phase refrigerant flows into the second heat exchanger 26, which acts as an evaporator. The refrigerant that flows into the second heat exchanger 26 exchanges heat with the second heat transfer medium, causing the liquid phase to evaporate and become a gas. The low-temperature, low-pressure gaseous refrigerant that flows out of the second heat exchanger 26 passes through the flow path switching device 72 and flows back into the compressor 71, where it is compressed and discharged as a high-temperature, high-pressure gas.

[0124] Furthermore, the first heat transfer medium, which circulates through the heat transfer circuit 91B by the first heat transfer pump 29, is heated in the first heat exchanger 25 by exchanging heat with the high-temperature refrigerant. At this time, the refrigerant flowing through the first heat exchanger 25 is condensed. A portion of the heated first heat transfer medium is cooled in the heat transfer heat exchanger 41 by exchanging heat with the third heat transfer medium. The remaining heated first heat transfer medium flows into the load-side heat exchanger 51b. The high-temperature first heat transfer medium that flows into the load-side heat exchanger 51b is cooled by exchanging heat with the indoor air supplied by the load-side blower 52. At this time, the indoor air is warmed, and heating is performed in the room. The low-temperature first heat transfer medium that has passed through the load-side heat exchanger 51b merges with the low-temperature first heat transfer medium that has passed through the heat transfer heat exchanger 41 and flows back into the first heat exchanger 25. Here, since both the first heat transfer medium that has passed through the load-side heat exchanger 51 and the first heat transfer medium that has passed through the heat transfer medium heat exchanger 41 are low-temperature heat transfer mediums, the waste of the cold energy supplied from the third heat transfer medium in the heat transfer medium heat exchanger 41 is suppressed.

[0125] Furthermore, the second heat transfer medium, circulating through the heat transfer circuit 92B by the second heat transfer pump 30, is cooled by heat exchange with the low-temperature refrigerant in the second heat exchanger 26. During this process, the refrigerant flowing through the second heat exchanger 26 is evaporated. The cooled second heat transfer medium flows into the load-side heat exchanger 51. The low-temperature second heat transfer medium that flows into the load-side heat exchanger 51 is heated by heat exchange with the indoor air supplied by the load-side blower 52. During this process, the indoor air is cooled, and cooling is performed in the room.

[0126] As described above, in the refrigeration cycle device 1E of Embodiment 5, the heat transfer medium circuit 91B and the heat transfer medium circuit 92B are independent during simultaneous cooling and heating operation. Therefore, mixing of the first heat transfer medium and the second heat transfer medium, and the waste of heat derived from renewable energy, is suppressed. Accordingly, the refrigeration cycle device 1E can suppress a decrease in energy saving performance. In particular, according to the example described in Embodiment 5, the cooling energy of the third heat transfer medium can be effectively utilized.

[0127] In the above explanation, the third heat transfer medium circulating in the water circuit of the heat transfer medium heat exchanger 41 was described as being at a lower temperature than the outside air during simultaneous cooling and heating operation. However, the heat transfer medium heat exchanger 41 may also be used when the temperature of the third heat transfer medium circulating in the water circuit of the heat transfer medium heat exchanger 41 is higher than or equal to the temperature of the outside air. Figure 18 is a refrigerant circuit diagram showing the flow of refrigerant and heat transfer medium during simultaneous cooling and heating operation in the refrigeration cycle device 1E according to Embodiment 5. When the temperature of the third heat transfer medium circulating in the water circuit of the heat transfer medium heat exchanger 41 is higher than or equal to the temperature of the outside air, the open / closed state of the on-off valves 200 corresponding to the load devices 5a and 5b is reversed from the open / closed state of the on-off valves 200 shown in Figure 17, as shown in Figure 18. In addition, the flow path switching device 72 is switched to the same direction as during full heating operation, that is, the direction in which the discharge side of the compressor 71 and the second heat exchanger 26 are connected, as shown by the dashed line in Figure 18.

[0128] In this configuration, a heat transfer medium circuit 91C is formed through which the heat transfer medium circulates between the first heat exchanger 25, the heat transfer medium heat exchanger 41, and the load-side heat exchanger 51a. Additionally, a heat transfer medium circuit 92C is formed through which the heat transfer medium circulates between the second heat exchanger 26 and the load-side heat exchanger 51b. The heat transfer medium circuit 91C corresponds to the "first heat transfer medium circuit" of this disclosure, and the heat transfer medium circuit 92C corresponds to the "second heat transfer medium circuit" of this disclosure. The first heat exchanger 25 functions as an evaporator that evaporates the refrigerant using a high-temperature first heat transfer medium heated by a third heat transfer medium flowing through a third heat transfer medium channel 41b and a high-temperature first heat transfer medium heated by passing through the load-side heat exchanger 51a. The second heat exchanger 26 functions as a condenser that evaporates the refrigerant using a low-temperature second heat transfer medium cooled by passing through the load-side heat exchanger 51b. In this case, the thermal energy of the third heat transfer medium can be effectively utilized. Furthermore, simply switching between cooling and heating operations in load devices 5a and 5b only requires reversing the open / closed state of the corresponding on-off valves 200.

[0129] The above describes the embodiments, but this disclosure is not limited to the embodiments described above, and various modifications or combinations are possible without departing from the spirit of this disclosure. The second bypass piping 902 and the second bypass valve 32 described in Embodiment 2 may be applied to the refrigeration cycle device 1 described in Embodiment 3. In addition, in the refrigeration cycle devices of Embodiments 2 to 5, as described in the modification of Embodiment 1, the heat transfer medium heat exchanger 41 may be omitted, and well water or the like may be directly circulated to the first heat exchanger.

[0130] Furthermore, the mounting locations of the first heat transfer fluid pumps 29 and 76, the second heat transfer fluid pump 30, and the third heat transfer fluid pump 42 are not limited as long as they can circulate the heat transfer fluid flowing through each heat transfer fluid pipe described in the embodiment. For example, the first heat transfer fluid pumps 29 and 76 may be installed outside the heat source unit and the relay unit. [Explanation of Symbols]

[0131] 1, 1A, 1B, 1C, 1D, 1E Refrigeration cycle unit, 2, 2A, 2B, 2C Heat source unit, 4 Auxiliary heat source unit, 5 Load unit, 7 Repeater unit, 21 Compressor, 22 Flow path switching device, 23 Refrigerant heat exchanger, 24 Heat source side blower, 25 First heat exchanger, 25a Refrigerant flow path, 25b Heat transfer fluid flow path, 26 Second heat exchanger, 26a Refrigerant flow path, 26b Heat transfer fluid flow path, 27 Main throttling device, 28 Sub-throttling device, 29 First heat transfer fluid pump, 30 Second heat transfer fluid pump, 31 First bypass valve, 32 Second bypass valve, 41 Heat transfer fluid heat exchanger, 41a First heat transfer fluid flow path, 41b Third heat transfer fluid flow path, 42 Third heat transfer fluid pump, 51, 51a, 51b Load side heat exchanger, 52, 52a, 52b Load side blower, 61 Tank, 71 Compressor, 72 Flow path switching device, 73 First heat exchanger, 73a Refrigerant flow path, 73b Heat transfer medium flow path, 74 Second heat exchanger, 74a Refrigerant flow path, 74b Heat transfer medium flow path, 75 Throttle device, 76 First heat transfer medium pump, 81 Refrigerant circuit, 82 Refrigerant circuit, 91 First heat transfer medium circuit, 91A, 92A, 91B, 92B, 91C, 92C Heat transfer medium circuit, 92 Second heat transfer medium circuit, 93 Third heat transfer medium circuit, 100 Control device, 101 Processing circuit, 102 Processor, 103 Memory, 104 Bus, 200 On / off valve, 201a First on / off valve, 202a Second on / off valve, 203a Third on / off valve, 204a Fourth on / off valve, 201b First on / off valve, 202b Second on / off valve, 203b Third on / off valve, 204b 4th shut-off valve, 201c 1st shut-off valve, 202c 2nd shut-off valve, 203c 3rd shut-off valve, 204c 4th shut-off valve, 301 Refrigerant temperature sensor, 401 Heat transfer medium temperature sensor, 501, 501a, 501b Indoor air temperature sensor, 701 Refrigerant piping, 702 Refrigerant piping, 801 1st heat transfer medium piping, 802 2nd heat transfer medium piping, 803 3rd heat transfer medium piping, 804 1st supply pipe, 805 1st return pipe, 806 2nd supply pipe, 807 2nd return pipe, 901 1st bypass pipe, 902 2nd bypass pipe.

Claims

1. A first heat transfer medium circuit in which a first heat transfer medium having heat derived from renewable energy circulates, A refrigerant circuit comprising: a compressor for compressing a first refrigerant; a first heat exchanger for performing heat exchange between the first heat transfer medium and the first refrigerant; a refrigerant flow path through a second heat exchanger for performing heat exchange between the second heat transfer medium and the first refrigerant; and a refrigerant heat exchanger for performing heat exchange between the first refrigerant and outdoor air. A second heat transfer circuit, which is independent of the first heat transfer circuit, and includes a load-side heat exchanger that performs heat exchange between the second heat transfer and a fluid that is to be heated or cooled, and a heat transfer flow path through which the second heat transfer of the second heat exchanger flows, A heat source side blower that supplies the outdoor air to the refrigerant heat exchanger, A first bypass pipe connecting the upstream and downstream sides of the refrigerant heat exchanger, A first bypass valve is provided in the first bypass piping and adjusts the flow rate of the first refrigerant, A control device for controlling the first bypass valve, The control device is If the rotation speed of the heat source side blower is below a threshold, the first bypass valve is opened. If the rotation speed of the heat source side blower is greater than the threshold, the first bypass valve is closed. Refrigeration cycle device.

2. A first heat transfer medium circuit in which a first heat transfer medium having heat derived from renewable energy is circulated, A refrigerant circuit comprising: a compressor for compressing a first refrigerant; a first heat exchanger for performing heat exchange between the first heat transfer medium and the first refrigerant; a refrigerant flow path through a second heat exchanger for performing heat exchange between the second heat transfer medium and the first refrigerant; and a refrigerant heat exchanger for performing heat exchange between the first refrigerant and outdoor air. A second heat transfer circuit, which is independent of the first heat transfer circuit, and includes a load-side heat exchanger that performs heat exchange between the second heat transfer and a fluid that is to be heated or cooled, and a heat transfer flow path through which the second heat transfer of the second heat exchanger flows, A main throttle device for reducing the pressure of the first refrigerant, A second bypass pipe connects the upstream side of the main throttling device to the downstream side of the second heat exchanger, based on the flow of the first refrigerant when cooling the fluid, A second bypass valve is provided in the second bypass piping and adjusts the flow rate of the first refrigerant, A control device for controlling the second bypass valve, and comprising The control device is When heating the fluid, the second bypass valve is closed. When cooling the fluid, the second bypass valve is opened. Refrigeration cycle device.

3. The system further comprises an auxiliary refrigerant circuit having an auxiliary compressor for compressing a second refrigerant different from the first refrigerant, an auxiliary refrigerant heat exchanger for performing heat exchange between the second refrigerant and outdoor air, and an auxiliary heat transfer medium refrigerant heat exchanger for performing heat exchange between the second refrigerant and the second heat transfer medium. A refrigeration cycle apparatus according to claim 1 or 2.

4. The system further includes an auxiliary heat source unit having a heat exchanger that supplies heat derived from renewable energy to the first heat transfer medium by exchanging heat between well water and the first heat transfer medium. A refrigeration cycle apparatus according to claim 1 or 2.

5. It has a load-side heat exchanger for cooling the fluid and a load-side heat exchanger for heating the fluid, The first heat transfer medium circuit is configured such that one of the multiple load-side heat exchangers is connected to the heat transfer medium heat exchanger and the heat transfer medium flow path of the first heat exchanger. The second heat transfer medium circuit is connected to the other of the plurality of load-side heat exchangers and to the heat transfer medium flow path of the second heat exchanger. The refrigeration cycle apparatus according to claim 4.

6. When the load-side heat exchanger constituting the second heat transfer medium circuit cools the fluid, the first heat exchanger acts as a condenser for condensing the first refrigerant, and the second heat exchanger acts as an evaporator for evaporating the first refrigerant. When the load-side heat exchanger constituting the second heat transfer circuit heats the fluid, the first heat exchanger acts as an evaporator to evaporate the first refrigerant, and the second heat exchanger acts as a condenser to condense the first refrigerant. A refrigeration cycle apparatus according to claim 1 or 2.

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