Heat pump device

Abstract

A heat pump device is provided with a heat source device, a relay device connected to the heat source device, and a plurality of load devices connected to the relay device. The heat source machine has a first refrigerant circuit in which a refrigerant circulates, and a first water heat exchanger that exchanges heat with the first refrigerant circuit. The relay device has a second refrigerant circuit in which the refrigerant circulates, and a second water heat exchanger that exchanges heat with the second refrigerant circuit. The first water heat exchanger, the second water heat exchanger, and the load device are connected by a first heat medium pipe to form a first heat medium circuit in which a heat medium circulates.

Description

Technical Field

[0001] The present disclosure relates to a heat pump device. Background Art

[0002] Various heat pump devices using refrigerants and heat media such as water have been disclosed in the past. For example, Patent Document 1 discloses a multi-connected air conditioner with two cold and hot water machines and a plurality of indoor units installed on each floor of a building. In the multi-connected air conditioner with cold and hot water machines, each outdoor unit is connected to a plurality of indoor units through cold and hot water pipes, and by using one outdoor unit for cooling operation and the other outdoor unit for heating operation, cooling operation and heating operation can be performed simultaneously in each indoor unit.

[0003] Patent Document 1: Japanese Patent Application Laid-Open No. 4-214134 Summary of the invention

[0004] Problem that the invention aims to solve

[0005] However, in the multi-connected air conditioner with cold and hot water units of Patent Document 1, the following pipes are required: two cold and hot water pipes connected to one outdoor unit for cold water to flow back and forth; and two cold and hot water pipes connected to the other outdoor unit for hot water to flow back and forth. Therefore, two cold and hot water pipes need to be installed in each outdoor unit installed outdoors, and the number of cold and hot water pipes installed is large, so the burden of the piping project is large.

[0006] The present disclosure has been made to solve the above-mentioned problems, and an object of the present disclosure is to provide a heat pump device capable of reducing the number of pipes connected to a heat source machine.

[0007] Solutions for solving problems

[0008] The heat pump device involved in the present disclosure is a heat pump device comprising a heat source machine, a relay machine connected to the heat source machine, and a plurality of load devices connected to the relay machine, wherein the heat source machine has a first refrigerant circuit for circulation of a refrigerant and a first water heat exchanger for heat exchange with the first refrigerant circuit, the relay machine has a second refrigerant circuit for circulation of a refrigerant and a second water heat exchanger for heat exchange with the second refrigerant circuit, the first water heat exchanger, the second water heat exchanger, and the load devices are connected via a first heat medium piping to form a first heat medium circuit for circulation of a heat medium.

[0009] Effects of the Invention

[0010] According to the present disclosure, when cooling and heating are performed simultaneously in multiple load devices, cooling or heating can be performed respectively using the first refrigerant circuit provided in the heat source machine and the second refrigerant circuit provided in the relay machine, thereby reducing the number of pipes connected to the heat source machine. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 This is a diagram schematically showing the configuration of the heat pump device according to the first embodiment.

[0012] Figure 2 This is a refrigerant circuit diagram of the heat pump device according to Embodiment 1.

[0013] Figure 3 This is a refrigerant circuit diagram showing a configuration in which the first pump is disposed in the relay unit of the heat pump device according to Embodiment 1.

[0014] Figure 4 This is a refrigerant circuit diagram showing a configuration in which a first pump is disposed in a heat source unit and a relay unit of the heat pump device according to Embodiment 1.

[0015] Figure 5 This is a refrigerant circuit diagram showing the flow of the refrigerant and the heat medium when the heat pump device according to Embodiment 1 performs cooling in all load devices.

[0016] Figure 6 This is a refrigerant circuit diagram showing the flow of the refrigerant and the heat medium in the heat pump device according to Embodiment 1 when heating is performed in all load devices.

[0017] Figure 7 This is a refrigerant circuit diagram showing the flows of the refrigerant and the heat medium when the heat pump device according to Embodiment 1 is in cooling main operation.

[0018] Figure 8 This is a refrigerant circuit diagram showing the flows of the refrigerant and the heat medium when the heat pump device according to Embodiment 1 is in heating main operation.

[0019] Fig. 9 This is a refrigerant circuit diagram showing Modification 1 of the heat pump device according to Embodiment 1.

[0020] Fig.10 This is a diagram schematically showing a configuration of a second modification of the heat pump device according to the first embodiment.

[0021] Fig.11 This is a refrigerant circuit diagram of the heat pump device according to Embodiment 2.

[0022] Fig.12This is a graph showing the relationship between the cooling ratio of the load device and the ratio of the flow rate V1 of the heat medium flowing through the bypass flow path to the total flow rate V of the heat medium flowing through the first heat medium circuit in the heat pump device according to Embodiment 2.

[0023] Fig.13 This is a refrigerant circuit diagram of the heat pump device according to Embodiment 3.

[0024] Fig.14 This is a refrigerant circuit diagram of the heat pump device according to Embodiment 3 when hot water is produced in the first heat medium circuit.

[0025] Fig.15 This is a refrigerant circuit diagram of the heat pump device according to Embodiment 3 when chilled water is produced in the first heat medium circuit. DETAILED DESCRIPTION

[0026] Hereinafter, the embodiments of the present disclosure will be described with reference to the drawings. In addition, in each figure, the same or corresponding parts are given the same symbols, and their descriptions are appropriately omitted or simplified. In addition, the shapes, sizes, and configurations of the structures described in each figure can be appropriately changed.

[0027] Implementation method 1.

[0028] Figure 1 This is a diagram schematically showing the configuration of the heat pump device 100 according to the first embodiment. Figure 2 : is a refrigerant circuit diagram of the heat pump device 100 according to Embodiment 1. Figure 2 The hollow arrows shown in the figure represent the flow of the heat medium. Figure 1 and Figure 2 As shown, the heat pump device 100 involved in this embodiment 1 includes a heat source machine 1, a relay machine 2 connected to the heat source machine 1, and two load devices 3A and 3B connected to the relay machine 2. As an example, the heat source machine 1 is an outdoor unit. As an example, the load devices 3A and 3B are indoor units. The heat source machine 1 is, for example, installed on the roof of a building 200. The relay machine 2 and the load devices 3A and 3B are, for example, installed inside the building 200. The structural elements constituting the heat source machine 1, the relay machine 2, and the load devices 3A and 3B are controlled by the control device 6.

[0029] like Figure 2 As shown, the heat source unit 1 has a first refrigerant circuit 10 for refrigerant circulation and a first water heat exchanger 11 for heat exchange with the first refrigerant circuit 10. The relay unit 2 has a second refrigerant circuit 20 for refrigerant circulation, a second water heat exchanger 21 for heat exchange with the second refrigerant circuit 20, and a third water heat exchanger 22 for heat exchange with the second refrigerant circuit 20. The load devices 3A and 3B each have a load-side heat exchanger 30.

[0030] In the first refrigerant circuit 10, for example, flammable refrigerants such as R290, NH3, and olefins (R1234yf, R1234ze(E), R1123, R1132(E), etc.) are sealed. This is because the heat source machine 1 is mainly installed outdoors, and a refrigerant that is flammable but has a small global warming effect is used. In the second refrigerant circuit 20, for example, non-flammable or slightly flammable refrigerants such as R410A, R32, olefins, and mixtures of these refrigerants are sealed. This is because the relay machine 2 is mainly installed indoors. In addition, the refrigerant sealed in the first refrigerant circuit 10 and the refrigerant sealed in the second refrigerant circuit 20 are not limited to the above-mentioned refrigerants, and refrigerants generally used in current air conditioners such as R410A or R32, R290, CO2NH3, olefins, their mixed refrigerants, and other types of refrigerants may also be used. For example, as for the refrigerant sealed in the second refrigerant circuit 20, in consideration of safety, a flammable refrigerant such as R290, NH3, or olefin may be sealed.

[0031] The amount of refrigerant sealed in the first refrigerant circuit 10 is greater than the amount of refrigerant sealed in the second refrigerant circuit 20. As an example, the amount of refrigerant sealed in the first refrigerant circuit 10 is less than 5 kg. As an example, the amount of refrigerant sealed in the second refrigerant circuit 20 is less than 1 kg, which is a benchmark when a flammable refrigerant is used indoors. The first refrigerant circuit 10 is mainly used for load devices 3A and 3B with large operating loads. That is, in order to improve operating efficiency, the amount of refrigerant sealed in the first refrigerant circuit 10 is greater than the amount of refrigerant sealed in the second refrigerant circuit 20.

[0032] In the heat pump device 100, the first water heat exchanger 11, the second water heat exchanger 21, and the load-side heat exchanger 30 are connected by the first heat medium pipe 40 to form a first heat medium circuit 4 in which the heat medium circulates. In addition, in the heat pump device 100, the third water heat exchanger 22 and the load-side heat exchanger 30 are connected by the second heat medium pipe 50 to form a second heat medium circuit 5 in which the heat medium circulates. The first heat medium circuit 4 and the second heat medium circuit 5 are provided with first flow path switching devices 4a and 5a for switching the flow path of the heat medium flowing into the load devices 3A and 3B to the first heat medium circuit 4 or the second heat medium circuit 5. In addition, the heat medium is, for example, water, salt water, or a mixture of salt water and water.

[0033] First, the structure of the heat source machine 1 is described. The heat source machine 1 has a first refrigerant circuit 10 for circulating refrigerant. The first refrigerant circuit 10 is a structure in which a first compressor 12, a first flow path switching valve 13, a heat source side heat exchanger 14, a first expansion mechanism 15, and a first water heat exchanger 11 are sequentially connected through refrigerant piping. In addition, the first refrigerant circuit 10 may also include other structural elements in addition to the above-mentioned structural elements, and a part of the structure may be omitted.

[0034] The first compressor 12 is, for example, a variable frequency compressor. When the first compressor 12 is a variable frequency compressor, the operating frequency can be arbitrarily changed by using a variable frequency circuit or the like to change the ejection capacity of the refrigerant per unit time. In this case, the operation of the variable frequency circuit is controlled by the control device 6. The refrigerant ejected from the first compressor 12 flows into the heat source side heat exchanger 14 and / or the first water heat exchanger 11 via the first flow path switching valve 13.

[0035] As an example, the first flow path switching valve 13 is a four-way valve having a function of switching the flow path of the refrigerant. The first flow path switching valve 13 switches the refrigerant flow path in a manner that connects the refrigerant discharge side of the first compressor 12 to the heat source side heat exchanger 14 and connects the refrigerant suction side of the first compressor 12 to the first water heat exchanger 11 during cooling operation. On the other hand, the first flow path switching valve 13 switches the refrigerant flow path in a manner that connects the refrigerant discharge side of the first compressor 12 to the first water heat exchanger 11 and connects the refrigerant suction side of the first compressor 12 to the heat source side heat exchanger 14 during heating operation. In addition, the first flow path switching valve 13 may be formed by combining a two-way valve or a three-way valve.

[0036] The heat source side heat exchanger 14 functions as a condenser during cooling operation. In addition, the heat source side heat exchanger 14 functions as an evaporator during heating operation. The heat source side heat exchanger 14 sucks outdoor air through the heat source side blower 16, and discharges the air after heat exchange with the refrigerant flowing inside to the outside.

[0037] The first expansion mechanism 15 is for decompressing and expanding the refrigerant flowing in the first refrigerant circuit 10 , and is constituted by, for example, an electronic expansion valve whose opening degree is variably controlled.

[0038] The first water heat exchanger 11 is used to perform heat exchange between the heat medium and the refrigerant. The first water heat exchanger 11 forms the flow path of the first refrigerant circuit 10 and the flow path of the first heat medium circuit 4. That is, the first water heat exchanger 11 forms the device constituting the first refrigerant circuit 10 and the device constituting the first heat medium circuit 4. The first water heat exchanger 11 functions as an evaporator during cooling operation, performs heat exchange between the refrigerant flowing out of the first expansion mechanism 15 and the heat medium, evaporates the refrigerant to gasify, and cools the heat medium. The first water heat exchanger 11 functions as a condenser during heating operation, performs heat exchange between the refrigerant flowing in from the first compressor 12 and the heat medium, condenses the refrigerant to liquefy or gas-liquid two-phase, and heats the heat medium.

[0039] The relay unit 2 includes a second refrigerant circuit 20 for circulating refrigerant, a second water heat exchanger 21 for performing heat exchange with the second refrigerant circuit 20, a third water heat exchanger 22 for performing heat exchange with the second refrigerant circuit 20, and first flow path switching devices 4a and 5a for switching the flow path of the heat medium flowing into the load devices 3A and 3B to the first heat medium circuit 4 or the second heat medium circuit 5. The second refrigerant circuit 20 is a structure in which a second compressor 23, a second flow path switching valve 24, a second water heat exchanger 21, a second expansion mechanism 25, and a third water heat exchanger 22 are sequentially connected through refrigerant piping. In addition, the second refrigerant circuit 20 may include other structural elements in addition to the above-mentioned structural elements, and a part of the structure may be omitted.

[0040] The second compressor 23 is, for example, an inverter compressor and has basically the same structure as the first compressor 12. The refrigerant discharged from the second compressor 23 flows into the second water heat exchanger 21 or the third water heat exchanger 22 via the second flow path switching valve 24.

[0041] As an example, the second flow path switching valve 24 is a four-way valve, and has basically the same structure as the first flow path switching valve 13. The second flow path switching valve 24 switches the refrigerant flow path in a manner that connects the refrigerant discharge side of the second compressor 23 to the second water heat exchanger 21 and connects the refrigerant suction side of the second compressor 23 to the third water heat exchanger 22 during cooling operation. On the other hand, the second flow path switching valve 24 switches the refrigerant flow path in a manner that connects the refrigerant discharge side of the second compressor 23 to the third water heat exchanger 22 and connects the refrigerant suction side of the second compressor 23 to the second water heat exchanger 21 during heating operation. In addition, the second flow path switching valve 24 may be configured by combining a two-way valve or a three-way valve.

[0042] The second expansion mechanism 25 is for decompressing and expanding the refrigerant circulating in the second refrigerant circuit 20 , and is constituted by, for example, an electronic expansion valve whose opening degree is variably controlled.

[0043] The second water heat exchanger 21 is used to perform heat exchange between the heat medium and the refrigerant. The second water heat exchanger 21 becomes the flow path of the second refrigerant circuit 20 and the flow path of the first heat medium circuit 4. In other words, the second water heat exchanger 21 becomes a device constituting the second refrigerant circuit 20 and a device constituting the first heat medium circuit 4. In addition, Figure 1 In the second water heat exchanger 21 shown, it is preferred that, especially when functioning as a condenser, the piping is configured in a manner such that the refrigerant circulating in the second refrigerant circuit 20 and the heat medium circulating in the first heat medium circuit 4 are in countercurrent to improve the heat exchange rate in the second water heat exchanger 21.

[0044] When the second water heat exchanger 21 functions as a condenser, it performs heat exchange between the refrigerant flowing in from the second compressor 23 and the heat medium circulating in the first heat medium pipe 40, condenses the refrigerant to liquefy or gas-liquid two-phase, and heats the heat medium. When the second water heat exchanger 21 functions as an evaporator, it performs heat exchange between the refrigerant flowing out from the second expansion mechanism 25 and the heat medium circulating in the first heat medium pipe 40, evaporates the refrigerant to gasify, and cools the heat medium.

[0045] The third water heat exchanger 22 is used to perform heat exchange between the heat medium and the refrigerant. The third water heat exchanger 22 becomes the flow path of the second refrigerant circuit 20 and the flow path of the second heat medium circuit 5. In other words, the third water heat exchanger 22 becomes a device constituting the second refrigerant circuit 20 and a device constituting the second heat medium circuit 5. In addition, Figure 1 In the third water heat exchanger 22 shown, it is preferred that, especially when functioning as a condenser, the piping is configured in a manner such that the refrigerant circulating in the second refrigerant circuit 20 and the heat medium circulating in the second heat medium circuit 5 are in countercurrent to improve the heat exchange rate in the third water heat exchanger 22.

[0046] When the third water heat exchanger 22 functions as an evaporator, the refrigerant flowing out of the second expansion mechanism 25 exchanges heat with the heat medium circulating in the second heat medium pipe 50, evaporates the refrigerant to gasify it, and cools the heat medium. When the third water heat exchanger 22 functions as a condenser, the refrigerant flowing in from the second compressor 23 exchanges heat with the heat medium circulating in the second heat medium pipe 50, condenses the refrigerant to liquefy it or converts it into a gas-liquid two-phase state, and heats the heat medium.

[0047] The first flow switching device 4a is provided at the inflow side and outflow side of the refrigerant of the load-side heat exchanger 30 in the first heat medium circuit 4. The first flow switching device 5a is provided at the inflow side and outflow side of the refrigerant of the load-side heat exchanger 30 in the second heat medium circuit 5. The first flow switching devices 4a and 5a are composed of, for example, a two-way valve, etc., and are controlled to be opened and closed by the control device 6. In addition, the first flow switching devices 4a and 5a can be composed of, for example, a two-way valve capable of controlling the opening degree (opening area) of the valve. The first flow switching devices 4a and 5a control the heat medium flowing into and out of the load-side heat exchanger 30 by being controlled to be opened and closed.

[0048] A first pump 41 for circulating the heat medium is provided in the first heat medium circuit 4. The first pump 41 is one of the devices constituting the first heat medium circuit 4, and is provided in the heat source machine 1 as an example. The first pump 41 sucks water in the first heat medium circuit 4, pressurizes it, and then sends it out to circulate it. The capacity of the first pump 41 is changed by a pump variable frequency drive device (not shown). The pump variable frequency drive device arbitrarily changes the drive frequency based on an instruction from the control device 6, thereby changing the capacity of the first pump 41.

[0049] Figure 3 This is a refrigerant circuit diagram showing a configuration in which the first pump 41 is disposed in the relay unit 2 of the heat pump device 100 according to Embodiment 1. Figure 4 1 is a refrigerant circuit diagram showing a configuration in which the first pump 41 is disposed in the heat source unit 1 and the relay unit 2 of the heat pump device 100 according to the first embodiment. Figure 3 As shown in FIG. 1 , the first pump 41 may be arranged on the relay machine 2. Figure 4 As shown, they are respectively provided in the heat source machine 1 and the relay machine 2. Figure 4 The heat pump device 100 shown has a structure in which two first pumps 41 are connected in series in consideration of the pressure loss of the heat medium flowing between the heat source device 1 and the relay device 2 and the pressure loss of the heat medium flowing between the relay device 2 and the load devices 3A and 3B.

[0050] In addition, a second pump 51 for circulating the heat medium is provided in the second heat medium circuit 5. The second pump 51 is one of the devices constituting the second heat medium circuit 5. The second pump 51 sucks water in the second heat medium circuit 5, pressurizes it, and then sends it out to circulate it. The capacity of the second pump 51 is changed by a pump variable frequency drive device (not shown). The pump variable frequency drive device arbitrarily changes the drive frequency based on the instruction from the control device 6, thereby changing the capacity of the second pump 51.

[0051] As the second pump 51, a pump having a smaller flow rate or head than the first pump 41 is used. This is because the second heat medium circuit 5 is formed by connecting the relay machine 2 and the load devices 3A and 3B, and the heat medium piping is shorter than the first heat medium circuit 4, and the pressure loss is not so large. By making the second pump 51 smaller than the first pump 41, the cost can be reduced, and the burden of the installation operation can also be reduced. In addition, as the second pump 51, a pump having the same flow rate or head as the first pump 41 can also be used.

[0052] The load devices 3A and 3B include a load-side heat exchanger 30 and a load-side blower 31. The load devices 3A and 3B generate a flow of air that allows air in the indoor space to pass through the load-side heat exchanger 30 and return to the indoor space. As an example, the load-side heat exchanger 30 is a fin-tube heat exchanger that performs heat exchange between the indoor air in the indoor space supplied from the load-side blower 31 and the heat medium. When the load-side heat exchanger 30 is in cooling operation, the heat medium cooler than the air passes through the heat transfer pipe of the load-side heat exchanger 30, thereby cooling the indoor space. On the other hand, when the load-side heat exchanger 30 is in heating operation, the heat medium hotter than the air passes through the heat transfer pipe of the load-side heat exchanger 30, thereby heating the indoor space. In addition, although not shown in the figure, the load devices 3A and 3B may also include a flow control device that adjusts the flow rate of the heat medium flowing into the load-side heat exchanger 30.

[0053] The control device 6 is used to control the overall operation of the heat pump device 100. Specifically, the control device 6 controls the drive frequency of the compressor, the rotation speed of the blower, the switching of the flow path switching device, the opening of the expansion mechanism, the drive frequency of the pump, etc. The control device 6 is composed of a computer having a memory for storing data and programs required for control and a CPU for executing the programs, dedicated hardware such as ASIC or FPGA, or both.

[0054] Next, description will be given of various operation operations performed by the heat pump device 100. The operation operations of the heat pump device 100 include four modes: cooling operation, heating operation, cooling-dominated operation, and heating-dominated operation.

[0055] Cooling operation refers to an operation mode in which only cooling can be performed in the load devices 3A and 3B, and the load devices 3A and 3B are in a state of cooling or stopping. Heating operation refers to an operation mode in which only heating can be performed in the load devices 3A and 3B, and the load devices 3A and 3B are in a state of heating or stopping. Cooling-main operation refers to an operation mode in which cooling and heating can be selected respectively according to the load devices 3A and 3B, and the cooling load is larger than the heating load in the simultaneous cooling and heating operation when the load device 3A or 3B performing cooling and the load device 3A or 3B performing heating exist at the same time. Heating-main operation refers to an operation mode in which cooling and heating can be selected respectively according to the load devices 3A and 3B, and the heating load is larger than the cooling load in the simultaneous cooling and heating operation when the load device 3A or 3B performing cooling and the load device 3A or 3B performing heating exist at the same time.

[0056] (Cooling operation)

[0057] First, refer to Figure 5 The cooling operation of the heat pump device 100 will be described. Figure 5 1 is a refrigerant circuit diagram showing the flow of refrigerant and heat medium in the heat pump device 100 involved in Embodiment 1 when cooling is performed in all load devices 3A and 3B. In addition, the white color indicated by the mark 4a indicates a state where the valve is open. In addition, the black color indicated by the mark 5a indicates a state where the valve is closed. In the heat pump device 100 involved in Embodiment 1, when cooling is performed in all load devices 3A and 3B, the first flow path switching device 4a is set to open, the first flow path switching device 5a is set to close, the second refrigerant circuit 20 is stopped, and only the first refrigerant circuit 10 and the first heat medium circuit 4 are operated.

[0058] In the first refrigerant circuit 10, the high-temperature and high-pressure gas refrigerant ejected from the first compressor 12 passes through the first flow path switching valve 13, flows to the heat source side heat exchanger 14, and exchanges heat with the air to be condensed and liquefied. The condensed and liquefied refrigerant is decompressed by the first expansion mechanism 15 to become a low-pressure gas-liquid two-phase refrigerant, flows to the first water heat exchanger 11, exchanges heat with the heat medium flowing in the first heat medium circuit 4, and evaporates and becomes gas. The gasified refrigerant passes through the first flow path switching valve 13 and is sucked into the first compressor 12 via the accumulator.

[0059] On the other hand, the heat medium flowing in the first heat medium circuit 4 is cooled by the refrigerant flowing to the first water heat exchanger 11 to become cold water, and then flows to the load side heat exchanger 30 via the relay unit 2, and is heated by exchanging heat with the indoor air in the indoor space. The heated heat medium flows into the first water heat exchanger 11 again via the relay unit 2.

[0060] (Heating operation)

[0061] Next, refer to Figure 6 The heating operation of the heat pump device 100 will be described. Figure 6 1 is a refrigerant circuit diagram showing the flow of refrigerant and heat medium in the heat pump device 100 involved in embodiment 1 when heating is performed in all load devices 3A and 3B. In addition, the white color indicated by the mark 4a indicates the state of valve opening. In addition, the black color indicated by the mark 5a indicates the state of valve closing. In the heat pump device 100 involved in embodiment 1, when heating is performed in all load devices 3A and 3B, the first flow path switching device 4a is set to open, the first flow path switching device 5a is set to close, the second refrigerant circuit 20 is stopped, and only the first refrigerant circuit 10 and the first heat medium circuit 4 are operated.

[0062] In the first refrigerant circuit 10, the high-temperature and high-pressure gas refrigerant discharged from the first compressor 12 passes through the first flow path switching valve 13 and flows to the first water heat exchanger 11. The refrigerant flowing to the first water heat exchanger 11 exchanges heat with the heat medium flowing in the first heat medium circuit 4 to be condensed and liquefied, is decompressed by the first expansion mechanism 15 to become a low-pressure gas-liquid two-phase refrigerant, and flows to the heat source side heat exchanger 14. The gas-liquid two-phase refrigerant flowing to the heat source side heat exchanger 14 exchanges heat with the air to be evaporated and gasified, passes through the first flow path switching valve 13, and is sucked into the first compressor 12 via the accumulator.

[0063] On the other hand, the heat medium flowing in the first heat medium circuit 4 is heated by the refrigerant flowing into the first water heat exchanger 11 to become hot water, and then flows to the load side heat exchanger 30 via the relay unit 2, and is cooled by exchanging heat with the indoor air in the indoor space. The cooled heat medium flows into the first water heat exchanger 11 again via the relay unit 2.

[0064] (Refrigeration main operation)

[0065] Next, refer to Figure 7 , a case where cooling is performed in one load device 3A and heating is performed in the other load device 3B, and a cooling-dominated operation is performed with a large cooling load. Figure 7 This is a refrigerant circuit diagram showing the flows of the refrigerant and the heat medium when the heat pump device 100 according to Embodiment 1 is in cooling main operation.

[0066] In the heat pump device 100, when cooling is performed in one load device 3A and heating is performed in the other load device 3B, the first refrigerant circuit 10, the first heat medium circuit 4, the second refrigerant circuit 20, and the second heat medium circuit 5 are operated. Then, in order to connect the load-side heat exchanger 30 of the load device 3A that performs cooling to the first heat medium circuit 4, the first flow switching device 4a is set to open and the first flow switching device 5a is set to close. In addition, in order to connect the load-side heat exchanger 30 of the load device 3B that performs heating to the second heat medium circuit 5, the first flow switching device 4a is set to close and the first flow switching device 5a is set to open.

[0067] In the first refrigerant circuit 10, the high-temperature and high-pressure gas refrigerant discharged from the first compressor 12 passes through the first flow path switching valve 13 and flows to the heat source side heat exchanger 14, where it exchanges heat with the air and is condensed and liquefied. The condensed and liquefied refrigerant is decompressed by the first expansion mechanism 15 to become a low-pressure gas-liquid two-phase refrigerant, flows to the second water heat exchanger 21, exchanges heat with the heat medium flowing in the first heat medium circuit 4, and evaporates and becomes gas. The gasified refrigerant passes through the first flow path switching valve 13 and is sucked into the first compressor 12 via the accumulator.

[0068] On the other hand, the heat medium flowing in the first heat medium circuit 4 is cooled by the refrigerant flowing to the first water heat exchanger 11 to become cold water, and then flows to the load-side heat exchanger 30 of the load device 3A via the relay unit 2, and is heated by heat exchange with the indoor air in the indoor space. The heated heat medium flows to the second water heat exchanger 21, exchanges heat with the refrigerant circulating in the second refrigerant circuit 20 to be cooled, and flows into the first water heat exchanger 11 again.

[0069] In the second refrigerant circuit 20, the high-temperature and high-pressure gas refrigerant ejected from the second compressor 23 flows through the second flow path switching valve 24 and flows to the third water heat exchanger 22, where it exchanges heat with the heat medium flowing in the second heat medium circuit 5 and is condensed and liquefied. The condensed and liquefied refrigerant is decompressed by the second expansion mechanism 25 to become a low-pressure gas-liquid two-phase refrigerant, flows to the second water heat exchanger 21, exchanges heat with the heat medium flowing in the first heat medium circuit 4 and evaporates and becomes gas. The gasified refrigerant passes through the second flow path switching valve 24 and is sucked into the second compressor 23 via the accumulator.

[0070] On the other hand, the heat medium flowing in the second heat medium circuit 5 is heated by the refrigerant flowing into the third water heat exchanger 22 to become hot water, and then flows into the load-side heat exchanger 30 of the load device 3B to exchange heat with the indoor air in the indoor space and be cooled. The cooled heat medium flows into the third water heat exchanger 22 again.

[0071] (Heating main operation)

[0072] Next, refer to Figure 8 , a case where cooling is performed in one load device 3A and heating is performed in the other load device 3B, and a heating-dominated operation with a large heating load is described. Figure 8 This is a refrigerant circuit diagram showing the flows of the refrigerant and the heat medium when the heat pump device according to Embodiment 1 is in heating main operation.

[0073] In the heat pump device 100, when cooling is performed in one load device 3A and heating is performed in the other load device 3B, the first refrigerant circuit 10, the first heat medium circuit 4, the second refrigerant circuit 20, and the second heat medium circuit 5 are operated. Then, in order to connect the load-side heat exchanger 30 of the load device 3A that performs cooling to the second heat medium circuit 5, the first flow switching device 4a is set to be closed and the first flow switching device 5a is set to be opened. In addition, in order to connect the load-side heat exchanger 30 of the load device 3B that performs heating to the first heat medium circuit 4, the first flow switching device 4a is set to be opened and the first flow switching device 5a is set to be closed.

[0074] In the first refrigerant circuit 10, the high-temperature and high-pressure gas refrigerant discharged from the first compressor 12 passes through the first flow path switching valve 13 and flows to the first water heat exchanger 11. The refrigerant flowing to the first water heat exchanger 11 exchanges heat with the heat medium flowing in the first heat medium circuit 4 to be condensed and liquefied, is decompressed by the first expansion mechanism 15 to become a low-pressure gas-liquid two-phase refrigerant, and flows to the heat source side heat exchanger 14. The gas-liquid two-phase refrigerant flowing to the heat source side heat exchanger 14 exchanges heat with the air to be evaporated and gasified, passes through the first flow path switching valve 13, and is sucked into the first compressor 12 via the accumulator.

[0075] On the other hand, the heat medium flowing in the first heat medium circuit 4 is heated by the refrigerant flowing to the first water heat exchanger 11 to become hot water, and then flows to the load-side heat exchanger 30 of the load device 3A via the relay unit 2, and is cooled by heat exchange with the indoor air in the indoor space. The cooled heat medium flows to the second water heat exchanger 21, is heated by heat exchange with the refrigerant circulating in the second refrigerant circuit 20, and flows into the first water heat exchanger 11 again.

[0076] In the second refrigerant circuit 20, the high-temperature and high-pressure gas refrigerant discharged from the second compressor 23 flows through the second flow path switching valve 24 to the second water heat exchanger 21, and exchanges heat with the heat medium flowing in the first heat medium circuit 4 to be condensed and liquefied. The condensed and liquefied refrigerant is decompressed by the second expansion mechanism 25 to become a low-pressure gas-liquid two-phase refrigerant, flows to the third water heat exchanger 22, exchanges heat with the heat medium flowing in the second heat medium circuit 5 to be evaporated and gasified. The gasified refrigerant passes through the second flow path switching valve 24 and is sucked into the second compressor 23 via the accumulator.

[0077] On the other hand, the heat medium flowing in the second heat medium circuit 5 is cooled by the refrigerant flowing to the third water heat exchanger 22 to become cold water, and then flows to the load-side heat exchanger 30 of the load device 3B to exchange heat with the indoor air in the indoor space and be heated. The heated heat medium flows into the third water heat exchanger 22 again.

[0078] (Simultaneous operation of heating and hot water supply)

[0079] Fig. 9 This is a refrigerant circuit diagram showing Modification 1 of the heat pump device 100 according to Embodiment 1. Fig. 9 The heat pump device 100 shown has a structure that includes a hot water storage tank for supplying hot water as a load device 3C. Fig. 9 In the example, one load device 3B is an indoor unit, and the other load device 3C is a hot water storage tank. Fig. 9 In the example, the case where heating is performed in the load device 3B is described, but cooling may also be performed in the load device 3B. Fig. 9 As an example, it is assumed that the heating load is larger than the hot water supply load.

[0080] The heat medium circulating in the second heat medium circuit 5 is water supplied to a hot water storage tank as the load device 3C. The hot water storage tank stores water supplied via a water supply pipe (not shown) and hot water heated by the third water heat exchanger 22 .

[0081] In the heat pump device 100, when heating is performed in one load device 3B and hot water is supplied in the other load device 3C, the first refrigerant circuit 10, the first heat medium circuit 4, the second refrigerant circuit 20, and the second heat medium circuit 5 are operated. Then, in order to connect the load-side heat exchanger 30 of the load device 3B that performs heating to the first heat medium circuit 4, the first flow switching device 4a is set to open and the first flow switching device 5a is set to close. In addition, in order to connect the load-side heat exchanger 30 of the load device 3C that performs hot water supply to the second heat medium circuit 5, the first flow switching device 4a is set to close and the first flow switching device 5a is set to open.

[0082] In the first refrigerant circuit 10, the high-temperature and high-pressure gas refrigerant discharged from the first compressor 12 passes through the first flow path switching valve 13 and flows to the first water heat exchanger 11. The refrigerant flowing to the first water heat exchanger 11 exchanges heat with the heat medium flowing in the first heat medium circuit 4 to be condensed and liquefied, is decompressed by the first expansion mechanism 15 to become a low-pressure gas-liquid two-phase refrigerant, and flows to the heat source side heat exchanger 14. The gas-liquid two-phase refrigerant flowing to the heat source side heat exchanger 14 exchanges heat with the air to be evaporated and gasified, passes through the first flow path switching valve 13, and is sucked into the first compressor 12 via the accumulator.

[0083] On the other hand, the heat medium flowing in the first heat medium circuit 4 is heated by the refrigerant flowing to the first water heat exchanger 11 to become hot water, and then flows to the load-side heat exchanger 30 of the load device 3B via the relay unit 2, and is cooled by heat exchange with the indoor air in the indoor space. The cooled heat medium flows to the second water heat exchanger 21, and is cooled by heat exchange with the refrigerant circulating in the second refrigerant circuit 20, and flows into the first water heat exchanger 11 again.

[0084] In the second refrigerant circuit 20, the high-temperature and high-pressure gas refrigerant ejected from the second compressor 23 flows through the second flow path switching valve 24 and flows to the third water heat exchanger 22, where it exchanges heat with the heat medium flowing in the second heat medium circuit 5 and is condensed and liquefied. The condensed and liquefied refrigerant is decompressed by the second expansion mechanism 25 to become a low-pressure gas-liquid two-phase refrigerant, flows to the second water heat exchanger 21, exchanges heat with the heat medium flowing in the first heat medium circuit 4 and evaporates and becomes gas. The gasified refrigerant passes through the second flow path switching valve 24 and is sucked into the second compressor 23 via the accumulator.

[0085] On the other hand, the heat medium flowing through the second heat medium circuit 5 is heated by the refrigerant flowing through the third water heat exchanger 22 to become hot water, and then stored in the storage tank.

[0086] In addition, the load devices 3B and 3C may all be hot water storage tanks for supplying hot water. In this case, the second flow path switching valve 24 may be omitted from the second refrigerant circuit 20 .

[0087] Fig.10 1 is a schematic structural diagram showing a second modification of the heat pump device 100 according to the first embodiment. The number of the heat source device 1, the relay device 2, and the load devices 3A and 3B is not limited to the above. Fig.10 As shown, more than two heat source machines 1 may be provided. When a plurality of heat source machines 1 are provided, the first heat medium pipes between the heat source machines 1 are connected to each other. In addition, more than two relay machines 2 may be provided. When a plurality of relay machines 2 are provided, the first heat medium pipes between the relay machines 2 are connected to each other. In addition, more than three load devices 3A and 3B connected to each relay machine 2 may be provided. In this case, all of the load devices 3A and 3B may be provided as indoor units, or a part or all of the load devices 3A and 3B may be provided as hot water storage tanks for hot water supply. In addition, a structure in which a part of the load devices 3A and 3B are directly connected to the heat source machine 1 without passing through the relay machine 2 may also be provided.

[0088] As described above, the heat pump device 100 according to the first embodiment includes a heat source machine 1, a relay machine 2 connected to the heat source machine 1, and a plurality of load devices 3A and 3B connected to the relay machine 2. The heat source machine 1 includes a first refrigerant circuit 10 for circulating a refrigerant and a first water heat exchanger 11 for performing heat exchange with the first refrigerant circuit 10. The relay machine 2 includes a second refrigerant circuit 20 for circulating a refrigerant and a second water heat exchanger 21 for performing heat exchange with the second refrigerant circuit 20. The first water heat exchanger 11, the second water heat exchanger 21, and the load devices 3A and 3B are connected by a first heat medium pipe 40, forming a first heat medium circuit 4 for circulating a heat medium.

[0089] Therefore, when the heat pump device 100 according to the first embodiment performs cooling and heating simultaneously in the plurality of load devices 3A and 3B, the first refrigerant circuit 10 provided in the heat source machine 1 and the second refrigerant circuit 20 provided in the relay machine 2 can be used to perform cooling or heating respectively. Therefore, the heat pump device 100 can set the number of pipes connecting the heat source machine 1 and the relay machine 2 to two, thereby reducing the number of pipes and alleviating the burden of the piping project.

[0090] Implementation method 2.

[0091] Next, refer to Fig.11 and Fig.12 A heat pump device 101 according to Embodiment 2 will be described. Fig.11This is a refrigerant circuit diagram of the heat pump device 101 according to Embodiment 2. In addition, the same reference numerals are attached to the same components as those of the heat pump device 100 described in Embodiment 1, and the description thereof is omitted as appropriate.

[0092] In the heat pump device 100, when cooling and heating are performed simultaneously in the plurality of load devices 3A and 3B, the second refrigerant circuit 20 and the second heat medium circuit 5 are operated, thereby reducing the load for generating cold and hot water in the heat source unit 1. Therefore, it is not necessary to allow all the heat medium flowing to the first heat medium circuit 4 to flow into the first water heat exchanger 11.

[0093] Therefore, in the heat pump device 101 according to the second embodiment, a bypass flow path 7 and a flow control device 8 are provided in the first heat medium circuit 4. The bypass flow path 7 is used to connect the first heat medium pipe 40 between the first water heat exchanger 11 and the second water heat exchanger 21 and the first heat medium pipe 40 between the first water heat exchanger 11 and the load side heat exchanger 30. The flow control device 8 is used to adjust the flow rate of the heat medium flowing into the first water heat exchanger 11 and the flow rate of the heat medium flowing into the outlet side of the first water heat exchanger 11 via the bypass flow path 7. The flow control device 8 includes a first flow control valve 8a provided between the inlet end of the bypass flow path 7 and the first water heat exchanger 11 and a second flow control valve 8b provided in the bypass flow path 7. In the heat pump device 101, when cooling and heating are performed simultaneously in the plurality of load devices 3A and 3B, the flow rates of the heat medium flowing to the first water heat exchanger 11 and the bypass flow path 7 can be adjusted by controlling the first flow control valve 8a and the second flow control valve 8b.

[0094] The first flow regulating valve 8a and the second flow regulating valve 8b are composed of, for example, a two-way valve capable of controlling the valve opening (opening area). The first flow regulating valve 8a controls the flow rate of the heat medium flowing into the first water heat exchanger 11 by adjusting the opening. The second flow regulating valve 8b controls the flow rate of the heat medium flowing into the bypass flow path 7 by adjusting the opening. The first flow regulating valve 8a and the second flow regulating valve 8b are controlled by the control device 6.

[0095] Fig.12 100% on the horizontal axis indicates a state in which only cooling is performed in the load devices 3A and 3B. On the other hand, 0% on the horizontal axis indicates a state in which only heating is performed in the load devices 3A and 3B.

[0096] like Fig.12 As shown, when only cooling or only heating is performed in the load devices 3A and 3B, that is, when the cooling ratio on the load side is 100% or 0%, the first flow regulating valve 8a is set to be fully open, the second flow regulating valve 8b is set to be fully closed, and the ratio of the flow rate V1 flowing to the bypass flow path 7 to the total flow rate V of the heat medium flowing in the first heat medium circuit 4 is set to 0%.

[0097] On the other hand, when cooling and heating are performed simultaneously in the plurality of load devices 3A and 3B, the openings of the first flow regulating valve 8a and the second flow regulating valve 8b are controlled according to the cooling ratio of the load devices 3A and 3B to adjust the ratio of the flow rate V1 flowing to the bypass flow path 7 to the total flow rate V of the heat medium flowing in the first heat medium circuit 4. As a result, the flow rate V2 of the heat medium flowing into the heat source unit 1 can be reduced, and thus the heat exchange efficiency can be improved.

[0098] In addition, when the cooling and heating loads in the load devices 3A and 3B remain unchanged ( Fig.12 At point A), the first flow regulating valve 8a is fully closed, the second flow regulating valve 8b is fully opened, and the flow rate V1 flowing to the bypass flow path 7 is set to 100%. In this way, the operation of the heat source machine 1 can be stopped, so the energy saving performance of the heat pump device 100 can be improved.

[0099] In addition, the bypass flow path 7 is provided in the relay unit 2 in the case of the example shown in the figure, but it can also be provided in the heat source unit 1. In addition, the heat pump device 101 involved in the second embodiment can also be as follows Fig. 9 As shown, a storage tank for hot water supply is used as a load device.

[0100] Implementation method 3.

[0101] Next, refer to Figure 13 to Figure 15 A heat pump device 102 according to Embodiment 3 will be described. Fig.13 This is a refrigerant circuit diagram of the heat pump device 102 according to Embodiment 3. In addition, the same reference numerals are attached to the same components as those of the heat pump device 100 described in Embodiment 1, and the description thereof is omitted as appropriate.

[0102] In the heat pump device 102 according to the third embodiment, in the first water heat exchanger 11, the heat exchange rate in the first water heat exchanger 11 is improved by configuring the piping so that the refrigerant circulating in the first refrigerant circuit 10 and the heat medium circulating in the first heat medium circuit 4 are countercurrent, and the heat exchange rate in the first water heat exchanger 11 is improved, and the energy saving performance is improved. The heat pump device 102 according to the third embodiment is particularly effective when a non-azeotropic mixed refrigerant with different boiling points and dew points is used, and the temperature difference between the refrigerant and the water can be reduced in each of the condensation process of the refrigerant (heating the water) and the evaporation process of the refrigerant (cooling the water), thereby improving the system efficiency.

[0103] like Fig.13 As shown, a second flow path switching device 9 for reversing the flow of the heat medium flowing into the first water heat exchanger 11 is provided in the first heat medium circuit 4 of the heat pump device 102. The second flow path switching device 9 has a first bypass pipe 90, a second bypass pipe 91, a first opening and closing valve 92, a second opening and closing valve 93, a third opening and closing valve 94, and a fourth opening and closing valve 95.

[0104] The first inlet end 90a of the first bypass pipe 90 is connected to the first heat medium pipe 40 between the first water heat exchanger 11 and the second water heat exchanger 21, and the first outlet end 90b of the first bypass pipe 90 is connected to the first heat medium pipe 40 between the first water heat exchanger 11 and the load devices 3A and 3B. The second inlet end 91a of the second bypass pipe 91 is connected to the first heat medium pipe 40 between the first water heat exchanger 11 and the first inlet end 90a of the first bypass pipe 90, and the second outlet end 91b of the second bypass pipe 91 is connected to the first outlet end 90b of the first bypass pipe 90 and the first heat medium pipe 40 between the load devices 3A and 3B.

[0105] The first opening and closing valve 92 is provided in the first heat medium pipe 40 between the first inlet end 90a of the first bypass pipe 90 and the second inlet end 91a of the second bypass pipe 91. The second opening and closing valve 93 is provided in the first bypass pipe 90. The third opening and closing valve 94 is provided in the second bypass pipe 91. The fourth opening and closing valve 95 is provided in the first heat medium pipe 40 between the first outlet end 90b of the first bypass pipe 90 and the second outlet end 91b of the second bypass pipe 91. The first opening and closing valve 92, the second opening and closing valve 93, the third opening and closing valve 94 and the fourth opening and closing valve 95 are composed of, for example, two-way valves, and are controlled to be opened and closed by the control device 6.

[0106] Fig.141 is a refrigerant circuit diagram of the heat pump device 102 according to Embodiment 3 when hot water is produced in the first heat medium circuit 4. In addition, the white colors indicated by the marks 92 and 95 indicate a valve open state. In addition, the black colors indicated by the marks 93 and 94 indicate a valve closed state. In the heat pump device 102, as shown in FIG. Fig.14 As shown, when hot water is produced in the first heat medium circuit 4, the first opening and closing valve 92 and the fourth opening and closing valve 95 are set to open, and the second opening and closing valve 93 and the third opening and closing valve 94 are set to close. In this case, the heat medium flowing in the first heat medium circuit 4 flows from the second water heat exchanger 21 to the first water heat exchanger 11, and after being heated by the refrigerant flowing to the first water heat exchanger 11 to become hot water, flows to the load side heat exchanger 30, exchanges heat with the indoor air in the indoor space, and is cooled. In the first refrigerant circuit 10, the high-temperature and high-pressure gas refrigerant ejected from the first compressor 12 flows to the first water heat exchanger 11 after passing through the first flow path switching valve 13. That is, in the first water heat exchanger 11, the refrigerant circulating in the first refrigerant circuit 10 and the heat medium circulating in the first heat medium circuit 4 are countercurrent.

[0107] Fig.15 1 is a refrigerant circuit diagram of the heat pump device 100 according to Embodiment 3 when cold water is produced in the first heat medium circuit 4. In addition, the white colors indicated by the marks 93 and 94 indicate a valve open state. In addition, the black colors indicated by the marks 92 and 95 indicate a valve closed state. In the heat pump device 102, as shown in FIG. Fig.15 As shown, when cold water is produced in the first heat medium circuit 4, the first opening and closing valve 92 and the fourth opening and closing valve 95 are set to be closed, and the second opening and closing valve 93 and the third opening and closing valve 94 are set to be opened. In this case, the heat medium flowing in the first heat medium circuit 4 flows from the second water heat exchanger 21 to the first bypass pipe 90 and flows to the first water heat exchanger 11. After the heat medium flowing to the first water heat exchanger 11 is cooled by the refrigerant flowing to the first water heat exchanger 11 and becomes cold water, it flows to the second bypass pipe 91 and flows to the load side heat exchanger 30, and is heated by heat exchange with the indoor air in the indoor space. In the first refrigerant circuit 10, the high-temperature and high-pressure gas refrigerant discharged from the first compressor 12 passes through the first flow path switching valve 13 and flows to the heat source side heat exchanger 14, and is condensed and liquefied by heat exchange with the air. The condensed and liquefied refrigerant is decompressed by the first expansion mechanism 15 to become a low-pressure gas-liquid two-phase refrigerant, and flows to the first water heat exchanger 11. That is, in the first water heat exchanger 11 , the refrigerant circulating in the first refrigerant circuit 10 and the heat medium circulating in the first heat medium circuit 4 form a countercurrent flow.

[0108] As described above, in the heat pump device 102 according to the third embodiment, in the first water heat exchanger 11, the refrigerant circulating in the first refrigerant circuit 10 and the heat medium circulating in the first heat medium circuit 4 are in countercurrent, thereby improving the heat exchange efficiency and energy saving.

[0109] The heat pump devices (100 to 102) have been described above based on the embodiments.

[0110] (100-102) is not limited to the structure of the above-mentioned embodiment. The structure of the above-mentioned heat pump device (100-102) is an example, and it may also include other structural elements, and it may also omit some structural elements. In short, the heat pump device (100-102) includes the range of design changes and application changes that are usually made by those skilled in the art within the scope of its technical concept.

[0111] (Explanation of Reference Numerals)

[0112] 1: heat source machine; 2: relay machine; 3A, 3B: load device; 4: first heat medium circuit; 4a: first flow path switching device; 5: second heat medium circuit; 5a: first flow path switching device; 6: control device; 7: bypass flow path; 8: flow control device; 8a: first flow control valve; 8b: second flow control valve; 9: second flow path switching device; 10: first refrigerant circuit; 11: first water heat exchanger; 12: first compressor; 13: first flow path switching valve; 14: heat source side heat exchanger; 15: first expansion mechanism; 16: heat source side air blower; 20: second refrigerant circuit; 21: second water heat exchanger; 22: third water heat exchanger; 23: second compressor; 24: second flow path switching valve; 25: second expansion mechanism; 30: load-side heat exchanger; 31: load-side blower; 40: first heat medium pipe; 41: first pump; 50: second heat medium pipe; 51: second pump; 90: first bypass pipe; 90a: first inlet end; 90b: first outlet end; 91: second bypass pipe; 91a: second inlet end; 91b: second outlet end; 92: first opening and closing valve; 93: second opening and closing valve; 94: third opening and closing valve; 95: fourth opening and closing valve; 100, 101, 102: heat pump device; 200: building.

Claims

1. A heat pump device comprising a heat source machine, a relay machine connected to the heat source machine, and a plurality of load devices connected to the relay machine, wherein: The heat source device includes a first refrigerant circuit for circulating a refrigerant and a first water heat exchanger for performing heat exchange with the first refrigerant circuit. The relay unit includes a second refrigerant circuit for circulating refrigerant and a second water heat exchanger for performing heat exchange with the second refrigerant circuit. The first water heat exchanger, the second water heat exchanger, and the load device are connected by a first heat medium pipe to form a first heat medium circuit in which a heat medium circulates.

2. The heat pump device according to claim 1, wherein: The relay unit further includes a third water heat exchanger for performing heat exchange with the second refrigerant circuit. The third water heat exchanger and the load device are connected via a second heat medium pipe to form a second heat medium circuit for circulating the heat medium. The first heat medium circuit and the second heat medium circuit are provided with a first flow path switching device that switches the flow path of the heat medium flowing into the load device to the first heat medium circuit or the second heat medium circuit.

3. The heat pump device according to claim 2, wherein: In the first refrigerant circuit, at least a first compressor, a first flow path switching valve, a heat source side heat exchanger, a first expansion mechanism, and the first water heat exchanger are sequentially connected by refrigerant piping. In the second refrigerant circuit, at least the second compressor, the second water heat exchanger, the second expansion mechanism, and the third water heat exchanger are sequentially connected by refrigerant pipes.

4. The heat pump device according to claim 2 or 3, wherein: A first pump for circulating the heat medium is provided in the first heat medium circuit. A second pump for circulating the heat medium is provided in the second heat medium circuit. The second pump has a smaller flow rate or lift than the first pump.

5. The heat pump device according to claim 4, wherein: The first pump is provided in one or both of the heat source machine and the relay machine.

6. The heat pump device according to any one of claims 1 to 5, wherein: At least one of the plurality of load devices is an indoor unit having a load-side heat exchanger.

7. The heat pump device according to any one of claims 1 to 6, wherein: At least one of the plurality of load devices is a hot water storage tank storing hot water.

8. The heat pump device according to any one of claims 1 to 7, wherein: The amount of refrigerant sealed in the first refrigerant circuit is larger than the amount of refrigerant sealed in the second refrigerant circuit.

9. The heat pump device according to any one of claims 1 to 8, wherein: A flammable refrigerant is sealed in the first refrigerant circuit. The second refrigerant circuit contains a non-flammable or slightly flammable refrigerant.

10. The heat pump device according to any one of claims 1 to 9, wherein: The first heat medium circuit is provided with: a bypass flow path connecting the first heat medium pipe between the first water heat exchanger and the second water heat exchanger and the first heat medium pipe between the first water heat exchanger and the load device; as well as The flow rate regulating device regulates the flow rate of the heat medium flowing into the first water heat exchanger and the flow rate of the heat medium flowing into the outlet side of the first water heat exchanger via the bypass flow path.

11. The heat pump device according to any one of claims 1 to 9, wherein: The first heat medium circuit is provided with a second flow switching device for reversing the flow of the heat medium flowing into the first water heat exchanger.

12. The heat pump device according to claim 11, wherein: The second flow path switching device comprises: a first bypass pipe, wherein a first inlet end of the first bypass pipe is connected to the first heat medium pipe between the first water heat exchanger and the second water heat exchanger, and a first outlet end of the first bypass pipe is connected to the first heat medium pipe between the first water heat exchanger and the load device; a second bypass pipe, wherein a second inlet end of the second bypass pipe is connected to the first heat medium pipe between the first water heat exchanger and the first inlet end of the first bypass pipe, and a second outlet end of the second bypass pipe is connected to the first heat medium pipe between the first outlet end of the first bypass pipe and the load device; a first on-off valve provided on the first heat medium pipe between the first inlet end and the second inlet end; A second on-off valve is provided on the first bypass pipe; a third on-off valve, disposed on the second bypass pipe; as well as The fourth on-off valve is provided in the first heat medium pipe between the first outlet end and the second outlet end.

13. The heat pump device according to any one of claims 1 to 12, wherein: A plurality of the heat source machines are arranged, and the first heat medium pipes are connected to each other.

14. The heat pump device according to any one of claims 1 to 13, wherein: A plurality of the relay machines are arranged, and the first heat medium pipes are connected to each other.

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