Heat pump apparatus

Abstract

This heat pump apparatus comprises: 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 device has a first refrigerant circuit through 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 through 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 devices are connected by a first heat medium piping, and form a first heat medium circuit through which a heat medium circulates.

Description

heat pump equipment

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

[0002] Various heat pump systems using a refrigerant and a heat medium such as water have been disclosed. For example, Patent Document 1 discloses a water chiller / heater multi-air conditioner system including two water chillers and heaters and multiple indoor units installed on each floor of a building. In this water chiller / heater multi-air conditioner system, each outdoor unit is connected to the multiple indoor units by a water chiller / heater pipe. One outdoor unit is used for cooling operation and the other outdoor unit is used for heating operation, allowing each indoor unit to perform cooling and heating operations simultaneously.

[0003] Japanese Patent Application Publication No. 4-214134

[0004] However, the hot and cold water multi-air conditioner of Patent Document 1 requires two hot and cold water pipes connected to one outdoor unit for circulating cold water, and two hot and cold water pipes connected to the other outdoor unit for circulating hot water. Therefore, two hot and cold water pipes must be installed for each outdoor unit installed outdoors, and the large number of hot and cold water pipes required results in a heavy workload for piping work.

[0005] The present disclosure has been made to solve the above-mentioned problems, and aims to provide a heat pump device that can reduce the number of pipes connected to a heat source unit.

[0006] The heat pump device according to the present disclosure is a heat pump device including a heat source unit, a relay unit connected to the heat source unit, and a plurality of load devices connected to the relay unit, wherein the heat source unit has a first refrigerant circuit through which a refrigerant circulates and a first water heat exchanger that exchanges heat with the first refrigerant circuit, the relay unit has a second refrigerant circuit through which a refrigerant circulates and a second water heat exchanger that exchanges heat with the second refrigerant circuit, and the first water heat exchanger, the second water heat exchanger, and the load devices are connected by a first heat medium pipe to form a first heat medium circuit through which a heat medium circulates.

[0007] According to the present disclosure, when cooling and heating are performed simultaneously using multiple load devices, cooling or heating can be performed using the first refrigerant circuit provided in the heat source unit and the second refrigerant circuit provided in the relay unit, respectively, thereby reducing the number of pipes connected to the heat source unit.

[0008] 1 is a schematic configuration diagram of a heat pump device according to Embodiment 1. FIG. 2 is a refrigerant circuit diagram of a heat pump device according to Embodiment 1. FIG. 3 is a refrigerant circuit diagram of a heat pump device according to Embodiment 1, showing a configuration in which a first pump is arranged in a relay unit. FIG. 4 is a refrigerant circuit diagram of a heat pump device according to Embodiment 1, showing a configuration in which a first pump is arranged in a heat source unit and a relay unit. FIG. 5 is a refrigerant circuit diagram of a heat pump device according to Embodiment 1, showing the flow of refrigerant and heat medium when cooling is performed by all load devices. FIG. 6 is a refrigerant circuit diagram of a heat pump device according to Embodiment 1, showing the flow of refrigerant and heat medium when heating is performed by all load devices. FIG. 7 is a refrigerant circuit diagram of a heat pump device according to Embodiment 1, showing the flow of refrigerant and heat medium when cooling is mainly performed. FIG. 8 is a refrigerant circuit diagram of a heat pump device according to Embodiment 1, showing the flow of refrigerant and heat medium when heating is mainly performed. Fig. 10 is a graph showing the relationship between the cooling rate of a load device and the ratio of the flow rate V1 of the heat medium flowing in the bypass flow path to the total flow rate V of the heat medium flowing in the first heat medium circuit in a heat pump device according to embodiment 2. Fig. 11 is a refrigerant circuit diagram of a heat pump device according to embodiment 3. Fig. 12 is a refrigerant circuit diagram of a heat pump device according to embodiment 3 when hot water is produced in the first heat medium circuit. Fig. 13 is a refrigerant circuit diagram of a heat pump device according to embodiment 3 when cold water is produced in the first heat medium circuit.

[0009] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. In each drawing, the same or corresponding parts are denoted by the same reference numerals, and their description will be omitted or simplified as appropriate. Furthermore, the shape, size, arrangement, etc. of the configurations shown in each drawing may be changed as appropriate.

[0010] Embodiment 1. FIG. 1 is a schematic diagram illustrating a heat pump apparatus 100 according to Embodiment 1. FIG. 2 is a refrigerant circuit diagram of the heat pump apparatus 100 according to Embodiment 1. Note that the outline arrows in FIG. 2 indicate the flow of the heat medium. As shown in FIGS. 1 and 2 , the heat pump apparatus 100 according to Embodiment 1 includes a heat source apparatus 1, a relay apparatus 2 connected to the heat source apparatus 1, and two load apparatuses 3A and 3B connected to the relay apparatus 2. The heat source apparatus 1 is, for example, an outdoor unit. The load apparatuses 3A and 3B are, for example, indoor units. The heat source apparatus 1 is installed, for example, on the roof of a building 200. The relay apparatus 2 and the load apparatuses 3A and 3B are installed, for example, inside the building 200. The components constituting the heat source apparatus 1, the relay apparatus 2, and the load apparatuses 3A and 3B are controlled by a control apparatus 6.

[0011] 2 , the heat source unit 1 has a first refrigerant circuit 10 through which a refrigerant circulates, and a first water heat exchanger 11 that exchanges heat with the first refrigerant circuit 10. The relay unit 2 has a second refrigerant circuit 20 through which a refrigerant circulates, a second water heat exchanger 21 that exchanges heat with the second refrigerant circuit 20, and a third water heat exchanger 22 that exchanges heat with the second refrigerant circuit 20. The load devices 3A and 3B each have a load-side heat exchanger 30.

[0012] The first refrigerant circuit 10 contains, for example, R290, NH ３The second refrigerant circuit 20 is filled with a non-flammable or slightly flammable refrigerant such as R410A, R32, olefin, or a mixture of these refrigerants. This is because the heat source unit 1 is mainly installed outdoors, and so a flammable refrigerant with a small global warming effect is used. The second refrigerant circuit 20 is filled with a non-flammable or slightly flammable refrigerant such as R410A, R32, olefin, or a mixture of these refrigerants. This is because the relay unit 2 is mainly installed indoors. The refrigerant filled in the first refrigerant circuit 10 and the second refrigerant circuit 20 is not limited to the above-mentioned refrigerants, and may be refrigerants commonly used in air conditioning at present, such as R410A or R32, R290, CO ２ NH ３ For example, the refrigerant sealed in the second refrigerant circuit 20 may be, in consideration of safety, R290, NH ３ A flammable refrigerant such as olefin may be enclosed.

[0013] The amount of refrigerant circulating through the first refrigerant circuit 10 is greater than the amount of refrigerant circulating through the second refrigerant circuit 20. The amount of refrigerant circulated through the first refrigerant circuit 10 is, for example, 5 kg or less. The amount of refrigerant circulated through the second refrigerant circuit 20 is, for example, less than 1 kg, which is the standard for indoor use of a flammable refrigerant. The first refrigerant circuit 10 is mainly used for the load devices 3A and 3B, which have a heavy operating load. In other words, to improve operating efficiency, the amount of refrigerant circulating through the first refrigerant circuit 10 is greater than the amount of refrigerant circulating through the second refrigerant circuit 20.

[0014] In the heat pump unit 100, the first water heat exchanger 11, the second water heat exchanger 21, and the load side heat exchanger 30 are connected by a first heat medium piping 40 to form a first heat medium circuit 4 through which the heat medium circulates. In the heat pump unit 100, the third water heat exchanger 22 and the load side heat exchanger 30 are connected by a second heat medium piping 50 to form a second heat medium circuit 5 through 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 that switch 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 heat medium is, for example, water, brine, or a mixture of brine and water.

[0015] First, we will explain the configuration of the heat source machine 1. The heat source machine 1 has a first refrigerant circuit 10 through which a refrigerant circulates. The first refrigerant circuit 10 is configured such that a first compressor 12, a first flow switching valve 13, a heat source side heat exchanger 14, a first expansion mechanism 15, and a first water heat exchanger 11 are connected in sequence by refrigerant piping. Note that the first refrigerant circuit 10 may include other components in addition to the above-mentioned components, or may omit some components.

[0016] The first compressor 12 is, for example, an inverter compressor. When the first compressor 12 is an inverter compressor, the operating frequency may be changed arbitrarily by an inverter circuit or the like to change the refrigerant discharge capacity per unit time. In this case, the operation of the inverter circuit is controlled by the control device 6. The refrigerant discharged from the first compressor 12 flows into the heat source side heat exchanger 14 and the first water heat exchanger 11 via the first flow path switching valve 13.

[0017] The first flow path switching valve 13 is, for example, a four-way valve and has a function of switching the refrigerant flow path. During cooling operation, the first flow path switching valve 13 connects the refrigerant discharge side of the first compressor 12 to the heat source side heat exchanger 14 and switches the refrigerant flow path to connect the refrigerant suction side of the first compressor 12 to the first water heat exchanger 11. Meanwhile, during heating operation, the first flow path switching valve 13 connects the refrigerant discharge side of the first compressor 12 to the first water heat exchanger 11 and switches the refrigerant flow path to connect the refrigerant suction side of the first compressor 12 to the heat source side heat exchanger 14. The first flow path switching valve 13 may be configured as a combination of two-way valves or three-way valves.

[0018] The heat source-side heat exchanger 14 functions as a condenser during cooling operation. The heat source-side heat exchanger 14 also functions as an evaporator during heating operation. The heat source-side heat exchanger 14 draws in outdoor air using the heat source-side blower 16, exchanges heat with the refrigerant flowing inside, and discharges the air to the outside.

[0019] The first expansion mechanism 15 reduces the pressure of the refrigerant flowing through the first refrigerant circuit 10 to expand it, and is configured, for example, by an electronic expansion valve whose opening degree is variably controlled.

[0020] The first water heat exchanger 11 exchanges heat between the heat medium and the refrigerant. The first water heat exchanger 11 is a flow path of the first refrigerant circuit 10 and a flow path of the first heat medium circuit 4. That is, the first water heat exchanger 11 is a component of the first refrigerant circuit 10 and a component of the first heat medium circuit 4. The first water heat exchanger 11 functions as an evaporator during cooling operation and exchanges heat between the refrigerant flowing out of the first expansion mechanism 15 and the heat medium, evaporating the refrigerant and gasifying it, thereby cooling the heat medium. The first water heat exchanger 11 functions as a condenser during heating operation and exchanges heat between the refrigerant flowing in from the first compressor 12 and the heat medium, condensing the refrigerant to liquefy it or to form a two-phase gas-liquid state, thereby heating the heat medium.

[0021] The relay unit 2 includes a second refrigerant circuit 20 through which a refrigerant circulates, a second water heat exchanger 21 that exchanges heat with the second refrigerant circuit 20, a third water heat exchanger 22 that exchanges heat with the second refrigerant circuit 20, and first flow path switching devices 4a and 5a that switch 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 includes a second compressor 23, a second flow path switching valve 24, the second water heat exchanger 21, a second expansion mechanism 25, and the third water heat exchanger 22, which are connected in sequence by refrigerant piping. Note that the second refrigerant circuit 20 may include other components in addition to the above components, or some components may be omitted.

[0022] The second compressor 23 is, for example, an inverter compressor, and has basically the same configuration 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 a second flow path switching valve 24.

[0023] The second flow path switching valve 24 is, for example, a four-way valve and has basically the same configuration as the first flow path switching valve 13. During cooling operation, the second flow path switching valve 24 switches the refrigerant flow path to connect the refrigerant discharge side of the second compressor 23 to the second water heat exchanger 21 and to connect the refrigerant suction side of the second compressor 23 to the third water heat exchanger 22. On the other hand, during heating operation, the second flow path switching valve 24 switches the refrigerant flow path to connect the refrigerant discharge side of the second compressor 23 to the third water heat exchanger 22 and to connect the refrigerant suction side of the second compressor 23 to the second water heat exchanger 21. The second flow path switching valve 24 may be configured as a combination of two-way valves or three-way valves.

[0024] The second expansion mechanism 25 reduces the pressure of the refrigerant circulating in the second refrigerant circuit 20 to expand it, and is configured, for example, by an electronic expansion valve whose opening degree is variably controlled.

[0025] The second water heat exchanger 21 exchanges heat between the heat medium and the refrigerant. The second water heat exchanger 21 forms a flow path of the second refrigerant circuit 20 and a flow path of the first heat medium circuit 4. In other words, the second water heat exchanger 21 forms a component of the second refrigerant circuit 20 and a component of the first heat medium circuit 4. In the second water heat exchanger 21 shown in Fig. 1, particularly when functioning as a condenser, it is preferable to configure the piping so that the refrigerant circulating through the second refrigerant circuit 20 and the heat medium circulating through the first heat medium circuit 4 flow in counterflow directions to increase the heat exchange rate in the second water heat exchanger 21.

[0026] When functioning as a condenser, the second water heat exchanger 21 exchanges heat between the refrigerant flowing in from the second compressor 23 and the heat medium circulating through the first heat medium piping 40, condensing the refrigerant to liquefy or convert it to a gas-liquid two-phase state, and heating the heat medium. When functioning as an evaporator, the second water heat exchanger 21 exchanges heat between the refrigerant flowing out from the second expansion mechanism 25 and the heat medium circulating through the first heat medium piping 40, evaporating the refrigerant to vaporize it, and cooling the heat medium.

[0027] The third water heat exchanger 22 exchanges heat between the heat medium and the refrigerant. The third water heat exchanger 22 serves as a flow path of the second refrigerant circuit 20 and a flow path of the second heat medium circuit 5. In other words, the third water heat exchanger 22 serves as a component of the second refrigerant circuit 20 and a component of the second heat medium circuit 5. In the third water heat exchanger 22 shown in Fig. 1, particularly when functioning as a condenser, it is preferable to configure the piping so that the refrigerant circulating through the second refrigerant circuit 20 and the heat medium circulating through the second heat medium circuit 5 flow in counterflow directions to increase the heat exchange rate in the third water heat exchanger 22.

[0028] When functioning as an evaporator, the third water heat exchanger 22 exchanges heat between the refrigerant flowing out from the second expansion mechanism 25 and the heat medium circulating through the second heat medium piping 50, evaporating the refrigerant and cooling the heat medium. When functioning as a condenser, the third water heat exchanger 22 exchanges heat between the refrigerant flowing in from the second compressor 23 and the heat medium circulating through the second heat medium piping 50, condensing the refrigerant to liquefy or convert it into a gas-liquid two-phase state, and heating the heat medium.

[0029] The first flow switching devices 4a are provided in the first heat medium circuit 4 on the inlet and outlet sides of the refrigerant of the load-side heat exchanger 30. The first flow switching devices 5a are provided in the second heat medium circuit 5 on the inlet and outlet sides of the refrigerant of the load-side heat exchanger 30. The first flow switching devices 4a and 5a are configured, for example, as two-way valves, and their opening and closing is controlled by the control device 6. The first flow switching devices 4a and 5a may be configured, for example, as two-way valves whose valve opening degree (opening area) can be controlled. The first flow switching devices 4a and 5a control the heat medium flowing in and out of the load-side heat exchanger 30 by controlling their opening and closing.

[0030] The first heat medium circuit 4 is provided with a first pump 41 that circulates the heat medium. The first pump 41 is one of the devices that constitute the first heat medium circuit 4, and is provided in the heat source unit 1, as an example. The first pump 41 draws water in the first heat medium circuit 4, applies pressure to it, and sends it out to circulate. The capacity of the first pump 41 is changed by a pump inverter drive device (not shown). The pump inverter drive device changes the capacity of the first pump 41 by arbitrarily changing the drive frequency based on instructions from the control device 6.

[0031] FIG. 3 is a refrigerant circuit diagram of the heat pump apparatus 100 according to the first embodiment, showing a configuration in which the first pump 41 is disposed in the relay unit 2. FIG. 4 is a refrigerant circuit diagram of the heat pump apparatus 100 according to the first embodiment, showing a configuration in which the first pump 41 is disposed in the heat source unit 1 and the relay unit 2. The first pump 41 may be provided in the relay unit 2 as shown in FIG. 3. Alternatively, the first pump 41 may be provided in each of the heat source unit 1 and the relay unit 2 as shown in FIG. 4. The heat pump apparatus 100 shown in FIG. 4 has two first pumps 41 connected in series, taking into account the pressure loss of the heat medium flowing between the heat source unit 1 and the relay unit 2 and the pressure loss of the heat medium flowing between the relay unit 2 and the load devices 3A and 3B.

[0032] The second heat medium circuit 5 is also provided with a second pump 51 for circulating the heat medium. The second pump 51 is one of the components constituting the second heat medium circuit 5. The second pump 51 draws water in the second heat medium circuit 5, applies pressure to it, and sends it out to circulate. The capacity of the second pump 51 is changed by a pump inverter drive device (not shown). The pump inverter drive device changes the capacity of the second pump 51 by arbitrarily changing the drive frequency based on instructions from the control device 6.

[0033] The second pump 51 has a smaller flow rate or head than the first pump 41. This is because the second heat medium circuit 5 connects the relay unit 2 and the load devices 3A and 3B, and has shorter heat medium piping than the first heat medium circuit 4, so pressure loss is not as large. Making the second pump 51 smaller than the first pump 41 reduces costs and the burden of installation work. The second pump 51 may have the same flow rate or head as the first pump 41.

[0034] The load devices 3A and 3B each include a load-side heat exchanger 30 and a load-side blower 31. The load devices 3A and 3B generate an air flow that passes air from the indoor space through the load-side heat exchanger 30 and returns the air to the indoor space. The load-side heat exchanger 30 is, for example, a fin-tube heat exchanger that exchanges heat between the indoor air in the indoor space supplied from the load-side blower 31 and a heat medium. During cooling operation, a heat medium that is colder than the indoor air passes through the heat transfer tubes of the load-side heat exchanger 30 to cool the indoor space. On the other hand, during heating operation, a heat medium that is warmer than the indoor air passes through the heat transfer tubes of the load-side heat exchanger 30 to heat the indoor space. Although not shown, the load devices 3A and 3B may each include a flow rate control device that adjusts the flow rate of the heat medium flowing into the load-side heat exchanger 30.

[0035] The control device 6 controls 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, 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 including a memory for storing data and programs required for control and a CPU for executing programs, dedicated hardware such as an ASIC or FPGA, or both.

[0036] Next, a description will be given of various operating modes performed by the heat pump device 100. The heat pump device 100 operates in four modes: cooling operation, heating operation, cooling-dominated operation, and heating-dominated operation.

[0037] Cooling operation is an operation mode in which only cooling is possible in the load devices 3A and 3B, and the load devices 3A and 3B are either cooling or stopped. Heating operation is an operation mode in which only heating is possible in the load devices 3A and 3B, and the load devices 3A and 3B are either heating or stopped. Cooling-dominated operation is an operation mode in which cooling or heating can be selected for each load device 3A and 3B, and in which the cooling load is larger than the heating load in simultaneous cooling and heating operation in which the load device 3A or 3B performing cooling and the load device 3A or 3B performing heating are present simultaneously. Heating-dominated operation is an operation mode in which cooling or heating can be selected for each load device 3A and 3B, and in which the heating load is larger than the cooling load in simultaneous cooling and heating operation in which the load device 3A or 3B performing cooling and the load device 3A or 3B performing heating are present simultaneously.

[0038] (Cooling Operation) First, referring to Figure 5, the cooling operation of the heat pump unit 100 will be described. Figure 5 is a refrigerant circuit diagram showing the flow of refrigerant and heat medium in the heat pump unit 100 according to embodiment 1 when cooling is performed by all of the load devices 3A and 3B. Note that the white color indicated by reference symbol 4a indicates an open state of the valve. Furthermore, the black color indicated by reference symbol 5a indicates a closed state of the valve. In the heat pump unit 100 according to embodiment 1, when cooling is performed by all of the load devices 3A and 3B, the first flow switching device 4a is opened, the first flow switching device 5a is closed, the second refrigerant circuit 20 is stopped, and only the first refrigerant circuit 10 and the first heat medium circuit 4 are operated.

[0039] In the first refrigerant circuit 10, high-temperature, high-pressure gas refrigerant discharged from the first compressor 12 passes through the first flow switching valve 13 and flows to the heat source side heat exchanger 14, where it exchanges heat with air and condenses and liquefies. 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, where it exchanges heat with the heat medium flowing in the first heat medium circuit 4 and evaporates into gas. The gasified refrigerant passes through the first flow switching valve 13 and is drawn into the first compressor 12 via an accumulator.

[0040] On the other hand, the heat medium flowing through the first heat medium circuit 4 is cooled by the refrigerant flowing through the first water heat exchanger 11 to become cold water, and then flows through the relay unit 2 to the load-side heat exchanger 30, where it is heated by heat exchange with the indoor air in the indoor space. The heated heat medium passes through the relay unit 2 and flows into the first water heat exchanger 11 again.

[0041] (Heating Operation) Next, with reference to Fig. 6, a heating operation of the heat pump unit 100 will be described. Fig. 6 is a refrigerant circuit diagram showing the flow of refrigerant and heat medium in the heat pump unit 100 according to embodiment 1 when heating is performed by all of the load devices 3A and 3B. Note that the white color indicated by reference symbol 4a indicates an open state of the valve. Furthermore, the black color indicated by reference symbol 5a indicates a closed state of the valve. In the heat pump unit 100 according to embodiment 1, when heating is performed by all of the load devices 3A and 3B, the first flow switching device 4a is opened, the first flow switching device 5a is closed, the second refrigerant circuit 20 is stopped, and only the first refrigerant circuit 10 and the first heat medium circuit 4 are operated.

[0042] In the first refrigerant circuit 10, high-temperature, high-pressure gas refrigerant discharged from the first compressor 12 passes through the first flow switching valve 13 and flows to the first water heat exchanger 11. The refrigerant that flows into the first water heat exchanger 11 exchanges heat with the heat medium flowing through the first heat medium circuit 4, condenses, and liquefies, and is reduced in pressure by the first expansion mechanism 15 to become a low-pressure gas-liquid two-phase refrigerant, which flows to the heat source-side heat exchanger 14. The gas-liquid two-phase refrigerant that flows into the heat source-side heat exchanger 14 exchanges heat with air and evaporates, passes through the first flow switching valve 13, and is drawn into the first compressor 12 via an accumulator.

[0043] On the other hand, the heat medium flowing through the first heat medium circuit 4 is heated by the refrigerant flowing through the first water heat exchanger 11 to become hot water, and then flows through the relay unit 2 to the load-side heat exchanger 30, where it is cooled by heat exchange with the indoor air in the indoor space. The cooled heat medium passes through the relay unit 2 and flows into the first water heat exchanger 11 again.

[0044] (Cooling-dominated operation) Next, a case where one load device 3A performs cooling and the other load device 3B performs heating, and cooling-dominated operation with a large cooling load, will be described with reference to Fig. 7. Fig. 7 is a refrigerant circuit diagram showing the flow of the refrigerant and the heat medium in the heat pump device 100 according to the first embodiment when cooling is dominant operation.

[0045] In the heat pump unit 100, when one load device 3A performs cooling and the other load device 3B performs heating, 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, 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 opened and the first flow switching device 5a is closed. Also, 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 closed and the first flow switching device 5a is opened.

[0046] In the first refrigerant circuit 10, high-temperature, high-pressure gas refrigerant discharged from the first compressor 12 passes through the first flow switching valve 13 and flows to the heat source side heat exchanger 14, where it exchanges heat with air and condenses and liquefies. 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 second water heat exchanger 21, where it exchanges heat with the heat medium flowing in the first heat medium circuit 4 and evaporates and gasifies. The gasified refrigerant passes through the first flow switching valve 13 and is drawn into the first compressor 12 via an accumulator.

[0047] On the other hand, the heat medium flowing through the first heat medium circuit 4 is cooled by the refrigerant flowing through the first water heat exchanger 11 to become cold water, and then flows via the relay unit 2 to the load-side heat exchanger 30 of the load device 3A, where it 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, where it is cooled by heat exchange with the refrigerant circulating through the second refrigerant circuit 20, and then flows into the first water heat exchanger 11 again.

[0048] In the second refrigerant circuit 20, high-temperature, high-pressure gas refrigerant discharged from the second compressor 23 passes through the second flow switching valve 24 and flows to the third water heat exchanger 22, where it condenses and liquefies through heat exchange with the heat medium flowing in the second heat medium circuit 5. 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, and exchanges heat with the heat medium flowing in the first heat medium circuit 4 to evaporate and gasify. The gasified refrigerant passes through the second flow switching valve 24 and is drawn into the second compressor 23 via an accumulator.

[0049] 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 flows into the load-side heat exchanger 30 of the load device 3B, where it is cooled by heat exchange with the indoor air in the indoor space. The cooled heat medium flows into the third water heat exchanger 22 again.

[0050] (Heating-dominated operation) Next, a case where one load device 3A performs cooling and the other load device 3B performs heating, and heating-dominated operation with a large heating load, will be described with reference to Fig. 8. Fig. 8 is a refrigerant circuit diagram showing the flow of the refrigerant and the heat medium in the heat pump device according to embodiment 1 in heating-dominated operation.

[0051] In the heat pump unit 100, when one load device 3A performs cooling and the other load device 3B performs heating, 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, 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 closed and the first flow switching device 5a is opened. Also, 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 opened and the first flow switching device 5a is closed.

[0052] In the first refrigerant circuit 10, high-temperature, high-pressure gas refrigerant discharged from the first compressor 12 passes through the first flow switching valve 13 and flows to the first water heat exchanger 11. The refrigerant that flows into the first water heat exchanger 11 exchanges heat with the heat medium flowing through the first heat medium circuit 4, condenses, and liquefies, and is reduced in pressure by the first expansion mechanism 15 to become a low-pressure gas-liquid two-phase refrigerant, which flows to the heat source-side heat exchanger 14. The gas-liquid two-phase refrigerant that flows into the heat source-side heat exchanger 14 exchanges heat with air and evaporates, passes through the first flow switching valve 13, and is drawn into the first compressor 12 via an accumulator.

[0053] On the other hand, the heat medium flowing through the first heat medium circuit 4 is heated by the refrigerant flowing through the first water heat exchanger 11 to become hot water, and then flows via the relay unit 2 to the load-side heat exchanger 30 of the load device 3A, where it 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, where it is heated by heat exchange with the refrigerant circulating through the second refrigerant circuit 20, and then flows into the first water heat exchanger 11 again.

[0054] In the second refrigerant circuit 20, high-temperature, high-pressure gas refrigerant discharged from the second compressor 23 passes through the second flow switching valve 24 and flows to the second water heat exchanger 21, where it condenses and liquefies through heat exchange with the heat medium flowing in the first heat medium circuit 4. The condensed and liquefied refrigerant is reduced in pressure by the second expansion mechanism 25 to become a low-pressure gas-liquid two-phase refrigerant, 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 to evaporate and gasify. The gasified refrigerant passes through the second flow switching valve 24 and is drawn into the second compressor 23 via an accumulator.

[0055] On the other hand, the heat medium flowing through the second heat medium circuit 5 is cooled by the refrigerant flowing through the third water heat exchanger 22 to become cold water, and then flows into the load-side heat exchanger 30 of the load device 3B, where it is heated by heat exchange with the indoor air in the indoor space. The heated heat medium flows into the third water heat exchanger 22 again.

[0056] (Simultaneous operation of heating and hot water supply) FIG. 9 is a refrigerant circuit diagram showing a first modification of the heat pump apparatus 100 according to the first embodiment. The heat pump apparatus 100 shown in FIG. 9 is configured to have a hot water storage tank that supplies hot water as a load apparatus 3C. In FIG. 9, one load apparatus 3B is an indoor unit, and the other load apparatus 3C is a hot water storage tank. In FIG. 9, as an example, a case where heating is performed by the load apparatus 3B is described, but cooling may also be performed by the load apparatus 3B. Also, in FIG. 9, as an example, the heating load is assumed to be greater than the hot water supply load.

[0057] The heat medium circulating through the second heat medium circuit 5 is water supplied to a hot water storage tank, which is a load device 3C. The hot water storage tank stores water supplied via a water supply pipe (not shown) and hot water heated in the third water heat exchanger 22.

[0058] In the heat pump unit 100, when one load device 3B performs heating and the other load device 3C performs hot water supply, 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, 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 opened and the first flow switching device 5a is closed. Also, 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 closed and the first flow switching device 5a is opened.

[0059] In the first refrigerant circuit 10, high-temperature, high-pressure gas refrigerant discharged from the first compressor 12 passes through the first flow switching valve 13 and flows to the first water heat exchanger 11. The refrigerant that flows into the first water heat exchanger 11 exchanges heat with the heat medium flowing through the first heat medium circuit 4, condenses, and liquefies, and is reduced in pressure by the first expansion mechanism 15 to become a low-pressure gas-liquid two-phase refrigerant, which flows to the heat source-side heat exchanger 14. The gas-liquid two-phase refrigerant that flows into the heat source-side heat exchanger 14 exchanges heat with air and evaporates, passes through the first flow switching valve 13, and is drawn into the first compressor 12 via an accumulator.

[0060] On the other hand, the heat medium flowing through the first heat medium circuit 4 is heated by the refrigerant flowing through the first water heat exchanger 11 to become hot water, and then flows via the relay unit 2 to the load-side heat exchanger 30 of the load device 3B, where it 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, where it is cooled by heat exchange with the refrigerant circulating through the second refrigerant circuit 20, and then flows into the first water heat exchanger 11 again.

[0061] In the second refrigerant circuit 20, high-temperature, high-pressure gas refrigerant discharged from the second compressor 23 passes through the second flow switching valve 24 and flows to the third water heat exchanger 22, where it condenses and liquefies through heat exchange with the heat medium flowing in the second heat medium circuit 5. 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, and exchanges heat with the heat medium flowing in the first heat medium circuit 4 to evaporate and gasify. The gasified refrigerant passes through the second flow switching valve 24 and is drawn into the second compressor 23 via an accumulator.

[0062] 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 the hot water is stored in the storage tank.

[0063] The load devices 3B and 3C may all be hot water storage tanks that supply hot water. In this case, the second refrigerant circuit 20 may omit the second flow path switching valve 24.

[0064] FIG. 10 is a schematic diagram illustrating a second modification of the heat pump apparatus 100 according to the first embodiment. The number of heat source units 1, relay units 2, and load devices 3A and 3B is not limited to the above. As shown in FIG. 10 , two or more heat source units 1 may be installed. When multiple heat source units 1 are installed, the first heat medium pipes of the heat source units 1 are connected to each other. Furthermore, two or more relay units 2 may be installed. When multiple relay units 2 are installed, the first heat medium pipes of the relay units 2 are connected to each other. Furthermore, three or more load devices 3A and 3B may be installed and connected to each relay unit 2. In this case, all of the load devices 3A and 3B may be indoor units, or some or all of the load devices 3A and 3B may be hot water storage tanks for supplying hot water. Furthermore, some of the load devices 3A and 3B may be directly connected to the heat source unit 1 without going through the relay unit 2.

[0065] As described above, the heat pump apparatus 100 according to the first embodiment includes the heat source apparatus 1, the relay apparatus 2 connected to the heat source apparatus 1, and a plurality of load apparatuses 3A and 3B connected to the relay apparatus 2. The heat source apparatus 1 includes a first refrigerant circuit 10 through which a refrigerant circulates, and a first water heat exchanger 11 that exchanges heat with the first refrigerant circuit 10. The relay apparatus 2 includes a second refrigerant circuit 20 through which a refrigerant circulates, and a second water heat exchanger 21 that exchanges heat with the second refrigerant circuit 20. The first water heat exchanger 11, the second water heat exchanger 21, and the load apparatuses 3A and 3B are connected by a first heat medium pipe 40 to form a first heat medium circuit 4 through which a heat medium circulates.

[0066] Therefore, in the heat pump device 100 according to the first embodiment, when cooling and heating are performed simultaneously in a plurality of load devices 3A and 3B, cooling or heating can be performed by the first refrigerant circuit 10 provided in the heat source unit 1 and the second refrigerant circuit 20 provided in the relay unit 2. Therefore, the heat pump device 100 can reduce the number of pipes connecting the heat source unit 1 and the relay unit 2 to two, which reduces the number of pipes required and reduces the burden of piping work.

[0067] Embodiment 2 Next, a heat pump device 101 according to Embodiment 2 will be described with reference to Fig. 11 and Fig. 12. Fig. 11 is a refrigerant circuit diagram of the heat pump device 101 according to Embodiment 2. Note that the same components as those in the heat pump device 100 described in Embodiment 1 are denoted by the same reference numerals, and descriptions thereof will be omitted as appropriate.

[0068] In the heat pump apparatus 100, when cooling and heating are performed simultaneously by 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 producing chilled or hot water in the heat source unit 1. Therefore, it is not necessary to cause all of the heat medium flowing through the first heat medium circuit 4 to flow into the first water heat exchanger 11.

[0069] Therefore, in the heat pump apparatus 101 according to the second embodiment, a bypass flow path 7 and a flow rate control device 8 are provided in the first heat medium circuit 4. The bypass flow path 7 connects a first heat medium pipe 40 between the first water heat exchanger 11 and the second water heat exchanger 21 with a first heat medium pipe 40 between the first water heat exchanger 11 and the load side heat exchanger 30. The flow rate control device 8 adjusts the flow rate of the heat medium flowing into the first water heat exchanger 11 and the flow rate of the heat medium flowing to the outlet side of the first water heat exchanger 11 via the bypass flow path 7. The flow rate control device 8 includes a first flow rate 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 rate control valve 8b provided in the bypass flow path 7. In the heat pump device 101, when cooling and heating are performed simultaneously in multiple load devices 3A and 3B, the flow rate of the heat medium flowing through 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.

[0070] The first flow control valve 8a and the second flow control valve 8b are configured, for example, as two-way valves that can control the valve opening (opening area). The first flow control valve 8a adjusts its opening to control the flow rate of the heat medium flowing into the first water heat exchanger 11. The second flow control valve 8b adjusts its opening to control the flow rate of the heat medium flowing into the bypass flow path 7. The first flow control valve 8a and the second flow control valve 8b are controlled by the control device 6.

[0071] 12 is a graph showing the relationship between the cooling ratios of the load devices 3A and 3B and the ratio of the flow rate V1 of the heat medium flowing through the bypass flow path 7 to the total flow rate V of the heat medium flowing through the first heat medium circuit 4 in the heat pump device 101 according to embodiment 2. The horizontal axis represents the cooling ratios of the load devices 3A and 3B. The vertical axis represents the ratio of the flow rate V1 of the heat medium flowing through the bypass flow path 7 to the total flow rate V of the heat medium flowing through the first heat medium circuit 4. 100% on the horizontal axis represents a state in which only cooling is performed by the load devices 3A and 3B. On the other hand, 0% on the horizontal axis represents a state in which only heating is performed by the load devices 3A and 3B.

[0072] As shown in FIG. 12 , when the load devices 3A and 3B perform only cooling or only heating, that is, when the cooling ratio on the load side is 100% or 0%, the first flow control valve 8a is fully opened and the second flow control valve 8b is fully closed, and the ratio of the flow rate V1 flowing through the bypass flow path 7 to the total flow rate V of the heat medium flowing through the first heat medium circuit 4 is set to 0%.

[0073] On the other hand, when cooling and heating are performed simultaneously in a plurality of load devices 3A and 3B, the opening degrees of the first flow control valve 8a and the second flow control valve 8b are controlled according to the cooling ratio of the load devices 3A and 3B, and the ratio of the flow rate V1 flowing through the bypass flow path 7 to the total flow rate V of the heat medium flowing through the first heat medium circuit 4 is adjusted. This makes it possible to reduce the flow rate V2 of the heat medium flowing into the heat source unit 1, thereby improving the heat exchange efficiency.

[0074] When the cooling and heating loads of the load devices 3A and 3B do not change (point A in FIG. 12 ), the first flow control valve 8a is fully closed and the second flow control valve 8b is fully opened, and the flow rate V1 flowing through the bypass flow path 7 is set to 100%. This allows the operation of the heat source unit 1 to be stopped, thereby improving the energy efficiency of the heat pump device 100.

[0075] In the illustrated example, the bypass flow path 7 is provided in the relay unit 2, but may be provided in the heat source unit 1. The heat pump unit 101 according to the second embodiment may be configured as a storage tank for supplying hot water as a load device, as shown in FIG.

[0076] Embodiment 3 Next, a heat pump device 102 according to Embodiment 3 will be described with reference to Figures 13 to 15. Figure 13 is a refrigerant circuit diagram of the heat pump device 102 according to Embodiment 3. Note that the same components as those in the heat pump device 100 described in Embodiment 1 are denoted by the same reference numerals, and descriptions thereof will be omitted as appropriate.

[0077] In the heat pump device 102 according to the third embodiment, the piping is configured so that the refrigerant circulating in the first refrigerant circuit 10 and the heat medium circulating in the first heat medium circuit 4 flow in countercurrent directions in the first water heat exchanger 11, thereby increasing the heat exchange rate in the first water heat exchanger 11 and improving energy efficiency. The heat pump device 102 according to the third embodiment is particularly effective when a non-azeotropic refrigerant mixture having different boiling points and dew points is used, and can reduce the temperature difference between the refrigerant and water in each of the refrigerant condensation process (heating water) and the refrigerant evaporation process (cooling water), thereby improving system efficiency.

[0078] 13 , the first heat medium circuit 4 of the heat pump unit 102 is provided with a second flow switching device 9 that reverses the flow of the heat medium flowing into the first water heat exchanger 11. The second flow switching device 9 has a first bypass piping 90, a second bypass piping 91, a first on-off valve 92, a second on-off valve 93, a third on-off valve 94, and a fourth on-off valve 95.

[0079] The first bypass piping 90 has a first inlet end 90a connected to the first heat medium piping 40 between the first water heat exchanger 11 and the second water heat exchanger 21, and a first outlet end 90b connected to the first heat medium piping 40 between the first water heat exchanger 11 and the load devices 3A and 3B. The second bypass piping 91 has a second inlet end 91a connected to the first heat medium piping 40 between the first water heat exchanger 11 and the first inlet end 90a of the first bypass piping 90, and a second outlet end 91b connected to the first heat medium piping 40 between the first outlet end 90b of the first bypass piping 90 and the load devices 3A and 3B.

[0080] The first on-off valve 92 is provided in the first heat medium pipe 40 between the first inlet end 90 a of the first bypass pipe 90 and the second inlet end 91 a of the second bypass pipe 91. The second on-off valve 93 is provided in the first bypass pipe 90. The third on-off valve 94 is provided in the second bypass pipe 91. The fourth on-off valve 95 is provided in the first heat medium pipe 40 between the first outlet end 90 b of the first bypass pipe 90 and the second outlet end 91 b of the second bypass pipe 91. The first on-off valve 92, the second on-off valve 93, the third on-off valve 94, and the fourth on-off valve 95 are, for example, two-way valves, and their opening and closing is controlled by the control device 6.

[0081] 14 is a refrigerant circuit diagram of a heat pump unit 102 according to Embodiment 3, in which hot water is produced in the first heat medium circuit 4. The white colors indicated by the reference numerals 92 and 95 indicate that the valves are open. The black colors indicated by the reference numerals 93 and 94 indicate that the valves are closed. In the heat pump unit 102, as shown in FIG. 14 , when hot water is produced in the first heat medium circuit 4, the first on-off valve 92 and the fourth on-off valve 95 are opened, and the second on-off valve 93 and the third on-off valve 94 are closed. In this case, the heat medium flowing through the first heat medium circuit 4 flows from the second water heat exchanger 21 to the first water heat exchanger 11, where it is heated by the refrigerant flowing in the first water heat exchanger 11 to become hot water. After that, it flows to the load-side heat exchanger 30, where it is cooled by heat exchange with the indoor air in the indoor space. In the first refrigerant circuit 10, high-temperature, 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. 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 flow in counter directions.

[0082] FIG. 15 is a refrigerant circuit diagram of the heat pump unit 100 according to the third embodiment, in which chilled water is produced in the first heat medium circuit 4. The white colors indicated by the reference numerals 93 and 94 indicate that the valves are open. The black colors indicated by the reference numerals 92 and 95 indicate that the valves are closed. In the heat pump unit 102, as shown in FIG. 15 , when chilled water is produced in the first heat medium circuit 4, the first on-off valve 92 and the fourth on-off valve 95 are closed, and the second on-off valve 93 and the third on-off valve 94 are opened. In this case, the heat medium flowing through the first heat medium circuit 4 flows from the second water heat exchanger 21 to the first bypass piping 90 and then to the first water heat exchanger 11. The heat medium flowing in the first water heat exchanger 11 is cooled by the refrigerant flowing in the first water heat exchanger 11 to become chilled water, and then flows into the second bypass piping 91 and the load-side heat exchanger 30, where it is heated by heat exchange with the indoor air in the indoor space. In the first refrigerant circuit 10, high-temperature, high-pressure gas refrigerant discharged from the first compressor 12 passes through the first flow switching valve 13 and flows to the heat source side heat exchanger 14, where it exchanges heat with air and is condensed and liquefied. The condensed and liquefied refrigerant is reduced in pressure 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 flow in counter directions.

[0083] As described above, in the heat pump device 102 according to the third embodiment, the refrigerant circulating through the first refrigerant circuit 10 and the heat medium circulating through the first heat medium circuit 4 flow in countercurrent directions in the first water heat exchanger 11, thereby increasing the heat exchange rate and improving energy efficiency.

[0084] The heat pump devices (100-102) have been described above based on the embodiments, but the heat pump devices (100-102) are not limited to the configurations of the above-described embodiments. The configurations of the heat pump devices (100-102) described above are merely examples, and other components may be included, or some components may be omitted. In short, the heat pump devices (100-102) include the range of design modifications and application variations that are normally made by those skilled in the art, as long as they do not deviate from the technical concept thereof.

[0085] 1 Heat source unit, 2 Relay unit, 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 rate control device, 8a First flow rate control valve, 8b Second flow rate 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 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 piping, 41 First pump, 50 Second heat medium piping, 51 Second pump, 90 First bypass piping, 90a: First inlet end, 90b: First outlet end, 91: Second bypass piping, 91a: Second inlet end, 91b: Second outlet end, 92: First on-off valve, 93: Second on-off valve, 94: Third on-off valve, 95: Fourth on-off valve, 100, 101, 102: Heat pump device, 200: Building.

Claims

1. A heat pump apparatus including a heat source unit, a relay unit connected to the heat source unit, and a plurality of load devices connected to the relay unit, The heat source unit has a first refrigerant circuit through which a refrigerant circulates, and a first water heat exchanger that exchanges heat with the first refrigerant circuit, The relay unit has a second refrigerant circuit through which a 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 through which the heat medium circulates.

2. The relay unit further includes a third water heat exchanger that exchanges heat with the second refrigerant circuit, The third water heat exchanger and the load device are connected by a second heat medium pipe to form a second heat medium circuit in which a heat medium circulates, 2. The heat pump device according to claim 1, wherein the first heat medium circuit and the second heat medium circuit are provided with a first flow path switching device that switches a 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 first refrigerant circuit includes at least a first compressor, a first flow switching valve, a heat source side heat exchanger, a first expansion mechanism, and the first water heat exchanger, which are connected in sequence by refrigerant piping; The heat pump apparatus according to claim 2 , wherein the second refrigerant circuit includes at least a second compressor, the second water heat exchanger, a second expansion mechanism, and the third water heat exchanger, which are connected in sequence by refrigerant piping.

4. The first heat medium circuit is provided with a first pump that circulates a heat medium, The second heat medium circuit is provided with a second pump that circulates the heat medium, The heat pump apparatus according to claim 2 or 3, wherein the second pump has a flow rate or a head smaller than that of the first pump.

5. The heat pump apparatus according to claim 4 , wherein the first pump is provided in either one or both of the heat source unit and the relay unit.

6. The heat pump apparatus according to any one of claims 1 to 3, 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 3, wherein at least one of the plurality of load devices is a hot water storage tank for storing hot water.

8. The heat pump apparatus according to any one of claims 1 to 3, wherein an amount of refrigerant circulating through the first refrigerant circuit is greater than an amount of refrigerant circulating through the second refrigerant circuit.

9. A flammable refrigerant is sealed in the first refrigerant circuit, The heat pump apparatus according to any one of claims 1 to 3, wherein a non-flammable or slightly flammable refrigerant is sealed in the second refrigerant circuit.

10. The first heat medium circuit includes a bypass flow path connecting the first heat medium piping between the first water heat exchanger and the second water heat exchanger and the first heat medium piping between the first water heat exchanger and the load device; A flow rate control device is provided to adjust 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. The heat pump device according to any one of claims 1 to 3.

11. The heat pump apparatus according to any one of claims 1 to 3, wherein the first heat medium circuit is provided with a second flow path switching device that reverses the flow of the heat medium flowing into the first water heat exchanger.

12. The second flow path switching device is a first bypass pipe having a first inlet end connected to the first heat medium pipe between the first water heat exchanger and the second water heat exchanger and a first outlet end connected to the first heat medium pipe between the first water heat exchanger and the load device; a second bypass piping having a second inlet end connected to the first heat medium piping between the first water heat exchanger and the first inlet end of the first bypass piping, and a second outlet end connected to the first heat medium piping between the first outlet end of the first bypass piping and the load device; a first on-off valve provided in the first heat medium piping between the first inlet end and the second inlet end; a second on-off valve provided in the first bypass pipe; a third on-off valve provided in the second bypass pipe; The heat pump apparatus according to claim 11 , further comprising: a fourth on-off valve provided in the first heat medium pipe between the first outlet end and the second outlet end.

13. The heat pump apparatus according to any one of claims 1 to 3, wherein a plurality of the heat source units are arranged, and the first heat medium pipes are connected to each other.

14. The heat pump apparatus according to any one of claims 1 to 3, wherein a plurality of the relay units are arranged, and the first heat medium pipes are connected to each other.