Heat pump device

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

Technical Field

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

Background Art

[0002] Conventionally, various heat pump devices that utilize a refrigerant and a heat medium such as water have been disclosed. For example, in Patent Document 1, a chilled water multi-air conditioner including two chilled water units and a plurality of indoor units installed on each floor of a building is disclosed. In this chilled water multi-air conditioner, each outdoor unit and the plurality of indoor units are connected by chilled water pipes, respectively. By using one outdoor unit for cooling operation and the other outdoor unit for heating operation, cooling operation and heating operation can be simultaneously performed in each indoor unit.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the chilled water multi-air conditioner of Patent Document 1, two chilled water pipes through which cold water circulates and is connected to one outdoor unit, and two chilled water pipes through which warm water circulates and is connected to the other outdoor unit are required. Therefore, it is necessary to install two chilled water pipes for each outdoor unit installed outdoors. Since the number of installed chilled water pipes is large, the burden of piping work is great.

[0005] The present disclosure has been made to solve the above problems, and an object thereof is to provide a heat pump device capable of reducing the number of pipes connected to a heat source machine.

Means for Solving the Problems

[0006] The heat pump device according to this disclosure comprises 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, and 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, A third 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 transfer medium piping, forming a first heat transfer medium circuit through which the heat transfer medium circulates. Furthermore, the third water heat exchanger and the load device are connected by a second heat transfer piping, forming a second heat transfer circuit through which the heat transfer medium circulates, and the first heat transfer circuit and the second heat transfer circuit are provided with a first flow path switching device that switches the flow path of the heat transfer medium flowing into the load device to either the first heat transfer circuit or the second heat transfer circuit. They exist. [Effects of the Invention]

[0007] According to this disclosure, when cooling and heating are performed simultaneously by multiple load devices, the first refrigerant circuit provided in the heat source unit and the second refrigerant circuit provided in the relay unit can be used for cooling or heating respectively, thus reducing the number of pipes connected to the heat source unit. [Brief explanation of the drawing]

[0008] [Figure 1] This is a schematic diagram showing the heat pump device according to Embodiment 1. [Figure 2] This is a refrigerant circuit diagram of a heat pump device according to Embodiment 1. [Figure 3] This is a refrigerant circuit diagram showing a heat pump device according to Embodiment 1, in which the first pump is located in a relay unit. [Figure 4] This is a refrigerant circuit diagram showing a heat pump device according to Embodiment 1, in which the first pump is arranged in a heat source unit and a relay unit. [Figure 5] This is a refrigerant circuit diagram showing the flow of refrigerant and heat transfer medium in a heat pump device according to Embodiment 1 when cooling is performed on all load devices. [Figure 6] This is a refrigerant circuit diagram showing the flow of refrigerant and heat transfer medium in a heat pump device according to Embodiment 1 when heating is performed on all load devices. [Figure 7] This is a refrigerant circuit diagram showing the flow of refrigerant and heat transfer medium in a heat pump device according to Embodiment 1 when primarily operating in cooling mode. [Figure 8] This is a refrigerant circuit diagram showing the flow of refrigerant and heat transfer medium in a heat pump device according to Embodiment 1 when primarily operating for heating. [Figure 9] This is a refrigerant circuit diagram showing a modified example 1 of the heat pump device according to Embodiment 1. [Figure 10] This is a schematic diagram showing a modified example 2 of the heat pump device according to Embodiment 1. [Figure 11] This is a refrigerant circuit diagram of a heat pump device according to Embodiment 2. [Figure 12] This graph shows 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 channel to the total flow rate V of the heat medium flowing through the first heat medium circuit, in a heat pump device according to Embodiment 2. [Figure 13] This is a refrigerant circuit diagram of a heat pump device according to Embodiment 3. [Figure 14] This is a refrigerant circuit diagram for a heat pump device according to Embodiment 3, in which hot water is produced in the first heat transfer medium circuit. [Figure 15] This is a refrigerant circuit diagram for a heat pump device according to Embodiment 3, in which chilled water is produced in the first heat transfer medium circuit. [Modes for carrying out the invention]

[0009] Embodiments of this disclosure will be described below with reference to the drawings. In each drawing, the same or corresponding parts are denoted by the same reference numerals, and their descriptions are omitted or simplified as appropriate. Furthermore, the shape, size, and arrangement of the components shown in each drawing can be modified as appropriate.

[0010] Embodiment 1. FIG. 1 is a configuration diagram schematically showing a heat pump device 100 according to Embodiment 1. FIG. 2 is a refrigerant circuit diagram of the heat pump device 100 according to Embodiment 1. The white arrows shown in FIG. 2 indicate the flow of the heat medium. As shown in FIGS. 1 and 2, the heat pump device 100 according to 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. The heat source machine 1 is, for example, an outdoor unit. The load devices 3A and 3B are, for example, indoor units. The heat source machine 1 is installed, for example, on the roof of a building 200. The relay machine 2 and the load devices 3A and 3B are installed, for example, inside the building 200. The components constituting the heat source machine 1, the relay machine 2, the load devices 3A and 3B are controlled by a control device 6.

[0011] As shown in FIG. 2, the heat source machine 1 has a first refrigerant circuit 10 in which the refrigerant circulates and a first water heat exchanger 11 that exchanges heat with the first refrigerant circuit 10. The relay machine 2 has a second refrigerant circuit 20 in which the 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 is filled with a flammable refrigerant such as R290, NH3, or olefins (R1234yf, R1234ze(E), R1123, R1132(E), etc.). This is because the heat source unit 1 is mainly installed outdoors, and a refrigerant that is flammable but has a low global warming effect is used. The second refrigerant circuit 20 is filled with a non-flammable or slightly flammable refrigerant such as R410A, R32, olefins, or mixtures of these refrigerants. This is because the repeater unit 2 is mainly installed indoors. Note that the refrigerants filled in the first refrigerant circuit 10 and the second refrigerant circuit 20 are not limited to the refrigerants mentioned above, and other types of refrigerants commonly used in air conditioning today, such as R410A or R32, R290, CO2NH3, olefins, mixtures of these, or other types of refrigerants may be used. For example, the refrigerant sealed in the second refrigerant circuit 20 may be a flammable refrigerant such as R290, NH3, or olefin, while taking safety into consideration.

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

[0014] In the heat pump device 100, a first water heat exchanger 11, a second water heat exchanger 21, and a load-side heat exchanger 30 are connected by a first heat medium pipe 40, and a first heat medium circuit 4 through which the heat medium circulates is formed. Further, in the heat pump device 100, a third water heat exchanger 22 and the load-side heat exchanger 30 are connected by a second heat medium pipe 50, and a second heat medium circuit 5 through which the heat medium circulates is formed. 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. The heat medium is, for example, water, brine, or a mixture of brine and water.

[0015] First, the configuration of the heat source machine 1 will be described. The heat source machine 1 has a first refrigerant circuit 10 in which the refrigerant circulates. The first refrigerant circuit 10 is configured such that 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 by refrigerant pipes. In addition to the above-described components, the first refrigerant circuit 10 may include other components or may omit some of the configurations.

[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 arbitrarily changed by an inverter circuit or the like to change the discharge capacity of the refrigerant per unit time. In that 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 or and the first water heat exchanger 11 through the first flow path switching valve 13.

[0017] The first flow path switching valve 13 is, for example, a four-way valve and has the function of switching the flow path of the refrigerant. During cooling operation, the first flow path switching valve 13 switches the refrigerant flow path so that it connects the refrigerant discharge side of the first compressor 12 to the heat source side heat exchanger 14 and the refrigerant suction side of the first compressor 12 to the first water heat exchanger 11. On the other hand, during heating operation, the first flow path switching valve 13 switches the refrigerant flow path so that it connects the refrigerant discharge side of the first compressor 12 to the first water heat exchanger 11 and 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 by combining a two-way valve or a three-way valve.

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

[0019] The first expansion mechanism 15 depressurizes and expands the refrigerant flowing through the first refrigerant circuit 10, and is composed of, for example, an electronic expansion valve whose opening degree is variably controlled.

[0020] The first water heat exchanger 11 performs heat exchange between the heat transfer 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 transfer medium circuit 4. In other words, the first water heat exchanger 11 is a component of the first refrigerant circuit 10 and the first heat transfer medium circuit 4. During cooling operation, the first water heat exchanger 11 functions as an evaporator, performing heat exchange between the refrigerant flowing out from the first expansion mechanism 15 and the heat transfer medium, evaporating the refrigerant and vaporizing it, thereby cooling the heat transfer medium. During heating operation, the first water heat exchanger 11 functions as a condenser, performing heat exchange between the refrigerant flowing in from the first compressor 12 and the heat transfer medium, condensing the refrigerant into a liquefied or gas-liquid two-phase state, thereby heating the heat transfer medium.

[0021] The relay unit 2 includes a second refrigerant circuit 20 through which the 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 transfer medium flowing into the load devices 3A and 3B to either the first heat transfer medium circuit 4 or the second heat transfer medium circuit 5. The second refrigerant circuit 20 is configured such that 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 by refrigerant piping. In addition to the above-mentioned components, the second refrigerant circuit 20 may include other components, or some components may be omitted.

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

[0023] The second flow path switching valve 24 is, for example, a four-way valve, and is 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 by combining a two-way valve or a three-way valve.

[0024] The second expansion mechanism 25 depressurizes and expands the refrigerant circulating in the second refrigerant circuit 20, and is composed of, for example, an electronic expansion valve whose opening degree is variably controlled.

[0025] The second water heat exchanger 21 performs heat exchange between the heat transfer medium and the refrigerant. The second water heat exchanger 21 forms the flow path of the second refrigerant circuit 20 and the flow path of the first heat transfer medium circuit 4. In other words, the second water heat exchanger 21 is a component of the second refrigerant circuit 20 and a component of the first heat transfer medium circuit 4. In the second water heat exchanger 21 shown in Figure 1, it is preferable to configure the piping so that the refrigerant circulating in the second refrigerant circuit 20 and the heat transfer medium circulating in the first heat transfer medium circuit 4 flow in opposite directions, especially when the second water heat exchanger 21 functions as a condenser, in order to increase the heat exchange rate in the second water heat exchanger 21.

[0026] When the second water heat exchanger 21 functions as a condenser, it exchanges heat between the refrigerant flowing in from the second compressor 23 and the heat transfer medium circulating in the first heat transfer medium piping 40, condensing the refrigerant into liquefaction or gas-liquid two-phase phase, and heating the heat transfer medium. When the second water heat exchanger 21 functions as an evaporator, it exchanges heat between the refrigerant flowing out from the second expansion mechanism 25 and the heat transfer medium circulating in the first heat transfer medium piping 40, evaporating the refrigerant into vapor, and cooling the heat transfer medium.

[0027] The third water heat exchanger 22 performs heat exchange between the heat transfer medium and the refrigerant. The third water heat exchanger 22 forms the flow path of the second refrigerant circuit 20 and the flow path of the second heat transfer medium circuit 5. In other words, the third water heat exchanger 22 is a component of the second refrigerant circuit 20 and a component of the second heat transfer medium circuit 5. In the third water heat exchanger 22 shown in Figure 1, it is preferable to configure the piping so that the refrigerant circulating in the second refrigerant circuit 20 and the heat transfer medium circulating in the second heat transfer medium circuit 5 flow in opposite directions, especially when the third water heat exchanger 22 functions as a condenser, in order to increase the heat exchange rate in the third water heat exchanger 22.

[0028] When the third water heat exchanger 22 functions as an evaporator, it exchanges heat between the refrigerant flowing out of the second expansion mechanism 25 and the heat transfer medium circulating in the second heat transfer medium piping 50, evaporating and vaporizing the refrigerant while cooling the heat transfer medium. When the third water heat exchanger 22 functions as a condenser, it exchanges heat between the refrigerant flowing in from the second compressor 23 and the heat transfer medium circulating in the second heat transfer medium piping 50, condensing and liquefying or creating a gas-liquid two-phase system from the refrigerant, while also heating the heat transfer medium.

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

[0030] The first heat transfer medium circuit 4 is equipped with a first pump 41 for circulating the heat transfer medium. The first pump 41 is one of the components of the first heat transfer medium circuit 4 and is provided in the heat source unit 1 as an example. In the first heat transfer medium circuit 4, the first pump 41 draws in water, applies pressure, and sends it out for circulation. 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] Figure 3 is a refrigerant circuit diagram of a heat pump device 100 according to Embodiment 1, in which the first pump 41 is located on the relay unit 2. Figure 4 is a refrigerant circuit diagram of a heat pump device 100 according to Embodiment 1, in which the first pump 41 is located on the heat source unit 1 and the relay unit 2. The first pump 41 may be located on the relay unit 2, as shown in Figure 3. Alternatively, the first pump 41 may be located on the heat source unit 1 and the relay unit 2, respectively, as shown in Figure 4. The heat pump device 100 shown in Figure 4 has a configuration in which two first pumps 41 are connected in series, taking into account the pressure loss of the heat transfer medium flowing between the heat source unit 1 and the relay unit 2, and the pressure loss of the heat transfer medium flowing between the relay unit 2 and the load devices 3A and 3B.

[0032] Furthermore, the second heat transfer medium circuit 5 is equipped with a second pump 51 for circulating the heat transfer medium. The second pump 51 is one of the components of the second heat transfer medium circuit 5. In the second heat transfer medium circuit 5, the second pump 51 draws in water, applies pressure, and sends it out for circulation. 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 is designed to have a smaller flow rate or head than the first pump 41. The second heat transfer fluid circuit 5 connects the relay unit 2 with the load devices 3A and 3B, and the heat transfer fluid piping is shorter than that of the first heat transfer fluid circuit 4, resulting in less pressure loss. By making the second pump 51 smaller than the first pump 41, costs can be reduced and the burden of installation work can be lessened. Alternatively, 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 airflow that passes indoor air through the load-side heat exchanger 30 and returns it to the indoor space. The load-side heat exchanger 30 is, for example, a fin-tube type heat exchanger that performs heat exchange between indoor air supplied from the load-side blower 31 and a heat transfer medium. During cooling operation, the load-side heat exchanger 30 cools the indoor space by passing a heat transfer medium colder than air through its heat transfer tubes. On the other hand, during heating operation, the load-side heat exchanger 30 heats the indoor space by passing a heat transfer medium warmer than air through its heat transfer tubes. Although not shown in the diagram, the load devices 3A and 3B may also have a flow rate adjustment device that adjusts the flow rate of the heat transfer medium flowing into the load-side heat exchanger 30.

[0035] The control device 6 controls the operation of the entire heat pump system 100. Specifically, the control device 6 controls the compressor drive frequency, the blower rotation speed, the switching of the flow path switching device, the opening degree of the expansion mechanism, the pump drive frequency, etc. The control device 6 consists of a computer equipped with memory for storing data and programs necessary for control and a CPU for executing programs, dedicated hardware such as an ASIC or FPGA, or both.

[0036] Next, the operating operations of the heat pump system 100 during various operations will be described. There are four operating modes for the heat pump system 100: cooling operation, heating operation, cooling-dominant operation, and heating-dominant operation.

[0037] Cooling operation is an operating mode in which only cooling is possible for load devices 3A and 3B, and load devices 3A and 3B are either cooling or stopped. Heating operation is an operating mode in which only heating is possible for load devices 3A and 3B, and load devices 3A and 3B are either heating or stopped. Cooling-dominant operation is an operating mode in simultaneous cooling and heating operation where cooling or heating can be selected for each load device 3A and 3B, and a load device 3A or 3B performing cooling and a load device 3A or 3B performing heating are present at the same time, where the cooling load is greater than the heating load. Heating-dominant operation is an operating mode in simultaneous cooling and heating operation where cooling or heating can be selected for each load device 3A and 3B, and a load device 3A or 3B performing cooling and a load device 3A or 3B performing heating are present at the same time, where the heating load is greater than the cooling load.

[0038] (Air conditioning operation) First, the cooling operation of the heat pump device 100 will be explained with reference to Figure 5. Figure 5 is a refrigerant circuit diagram showing the flow of refrigerant and heat transfer medium when cooling is performed on all load devices 3A and 3B in the heat pump device 100 according to Embodiment 1. The white color indicated by reference numeral 4a indicates that the valve is open. The black color indicated by reference numeral 5a indicates that the valve is closed. In the heat pump device 100 according to Embodiment 1, when cooling is performed on all load devices 3A and 3B, the first flow path switching device 4a is opened, the first flow path switching device 5a is closed, the second refrigerant circuit 20 is stopped, and only the first refrigerant circuit 10 and the first heat transfer medium circuit 4 are operated.

[0039] In the first refrigerant circuit 10, the high-temperature, high-pressure gaseous refrigerant discharged from the first compressor 12 flows through the first flow path switching valve 13 to the heat source side heat exchanger 14, where it exchanges heat with air and condenses into a liquid. The condensed liquid refrigerant is depressurized in the first expansion mechanism 15 to become a low-pressure gas-liquid two-phase refrigerant, which flows to the first water heat exchanger 11, where it exchanges heat with the heat transfer medium flowing through the first heat transfer medium circuit 4 and evaporates into a gas. The gasified refrigerant passes through the first flow path switching valve 13 and is drawn into the first compressor 12 via the accumulator.

[0040] Meanwhile, the heat transfer medium flowing through the first heat transfer medium circuit 4 is cooled by the refrigerant that flows through the first water heat exchanger 11 to become chilled water. This chilled water then flows through the relay unit 2 to the load-side heat exchanger 30, where it is heated through heat exchange with the indoor air in the indoor space. The heated heat transfer medium then flows back into the first water heat exchanger 11 via the relay unit 2.

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

[0042] In the first refrigerant circuit 10, the high-temperature, high-pressure gaseous 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 that flows to the first water heat exchanger 11 exchanges heat with the heat transfer medium flowing through the first heat transfer medium circuit 4, condenses and liquefies, is depressurized in 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 that flows to the heat source side heat exchanger 14 exchanges heat with air, evaporates and becomes a gas, passes through the first flow path switching valve 13, and is drawn into the first compressor 12 via the accumulator.

[0043] Meanwhile, the heat transfer medium flowing through the first heat transfer medium circuit 4 is heated by the refrigerant flowing through the first water heat exchanger 11 to become hot water. This hot water 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 transfer medium then flows back into the first water heat exchanger 11 via the relay unit 2.

[0044] (Mainly air conditioning operation) Next, referring to Figure 7, we will describe a case where one load device 3A performs cooling and the other load device 3B performs heating, and where cooling is the primary mode of operation due to the larger cooling load. Figure 7 is a refrigerant circuit diagram showing the flow of refrigerant and heat transfer medium in a heat pump device 100 according to Embodiment 1 when cooling is the primary mode of operation.

[0045] In the heat pump system 100, when one load device 3A provides cooling and the other load device 3B provides heating, the first refrigerant circuit 10, the first heat transfer medium circuit 4, the second refrigerant circuit 20, and the second heat transfer medium circuit 5 are operated. Then, in order to connect the load-side heat exchanger 30 of the load device 3A that provides cooling with the first heat transfer medium circuit 4, the first flow path switching device 4a is opened and the first flow path switching device 5a is closed. Similarly, in order to connect the load-side heat exchanger 30 of the load device 3B that provides heating with the second heat transfer medium circuit 5, the first flow path switching device 4a is closed and the first flow path switching device 5a is opened.

[0046] In the first refrigerant circuit 10, the high-temperature, high-pressure gaseous 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 air and condenses into a liquid. The condensed liquid refrigerant is depressurized in the first expansion mechanism 15 to become a low-pressure gas-liquid two-phase refrigerant, which flows to the second water heat exchanger 21, where it exchanges heat with the heat transfer medium flowing through the first heat transfer medium circuit 4 and evaporates into a gas. The gasified refrigerant passes through the first flow path switching valve 13 and is drawn into the first compressor 12 via the accumulator.

[0047] Meanwhile, the heat transfer medium flowing through the first heat transfer medium circuit 4 is cooled by the refrigerant flowing through the first water heat exchanger 11 to become chilled water. This chilled water then flows through the relay unit 2 to the load-side heat exchanger 30 of the load device 3A, where it is heated through heat exchange with the indoor air in the indoor space. The heated heat transfer medium then flows to the second water heat exchanger 21, where it is cooled through heat exchange with the refrigerant circulating in the second refrigerant circuit 20, and then flows back into the first water heat exchanger 11.

[0048] In the second refrigerant circuit 20, the high-temperature, high-pressure gaseous refrigerant discharged from the second compressor 23 flows through the second flow path switching valve 24 to the third water heat exchanger 22, where it exchanges heat with the heat transfer medium flowing through the second heat transfer medium circuit 5 and condenses into a liquid. The condensed liquid refrigerant is depressurized in the second expansion mechanism 25 to become a low-pressure gas-liquid two-phase refrigerant, which flows to the second water heat exchanger 21, where it exchanges heat with the heat transfer medium flowing through the first heat transfer medium circuit 4 and evaporates into a gas. The gasified refrigerant passes through the second flow path switching valve 24 and is drawn into the second compressor 23 via the accumulator.

[0049] Meanwhile, the heat transfer medium flowing through the second heat transfer medium circuit 5 is heated by the refrigerant flowing through the third water heat exchanger 22 to become hot water, which then flows 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 transfer medium then flows back into the third water heat exchanger 22.

[0050] (Mainly heating operation) Next, referring to Figure 8, we will describe a case where cooling is performed with one load device 3A and heating is performed with the other load device 3B, and where heating is the primary operation with a large heating load. Figure 8 is a refrigerant circuit diagram showing the flow of refrigerant and heat transfer medium in a heat pump device according to Embodiment 1 when heating is the primary operation.

[0051] In the heat pump system 100, when one load device 3A provides cooling and the other load device 3B provides heating, the first refrigerant circuit 10, the first heat transfer medium circuit 4, the second refrigerant circuit 20, and the second heat transfer medium circuit 5 are operated. Then, in order to connect the load-side heat exchanger 30 of the load device 3A that provides cooling with the second heat transfer medium circuit 5, the first flow path switching device 4a is closed and the first flow path switching device 5a is opened. Similarly, in order to connect the load-side heat exchanger 30 of the load device 3B that provides heating with the first heat transfer medium circuit 4, the first flow path switching device 4a is opened and the first flow path switching device 5a is closed.

[0052] In the first refrigerant circuit 10, the high-temperature, high-pressure gaseous 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 that flows to the first water heat exchanger 11 exchanges heat with the heat transfer medium flowing through the first heat transfer medium circuit 4, condenses and liquefies, is depressurized in 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 that flows to the heat source side heat exchanger 14 exchanges heat with air, evaporates and becomes a gas, passes through the first flow path switching valve 13, and is drawn into the first compressor 12 via the accumulator.

[0053] Meanwhile, the heat transfer medium flowing through the first heat transfer medium circuit 4 is heated by the refrigerant flowing through the first water heat exchanger 11 to become hot water. This hot water then flows through 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 transfer medium then flows to the second water heat exchanger 21, where it is heated by heat exchange with the refrigerant circulating in the second refrigerant circuit 20, and then flows back into the first water heat exchanger 11.

[0054] In the second refrigerant circuit 20, the high-temperature, high-pressure gaseous refrigerant discharged from the second compressor 23 flows through the second flow path switching valve 24 to the second water heat exchanger 21, where it exchanges heat with the heat transfer medium flowing through the first heat transfer medium circuit 4 and condenses into a liquid. The condensed liquid refrigerant is depressurized in the second expansion mechanism 25 to become a low-pressure gas-liquid two-phase refrigerant, which flows to the third water heat exchanger 22, where it exchanges heat with the heat transfer medium flowing through the second heat transfer medium circuit 5 and evaporates into a gas. The gasified refrigerant passes through the second flow path switching valve 24 and is drawn into the second compressor 23 via the accumulator.

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

[0056] (Simultaneous operation of heating and hot water supply) Figure 9 is a refrigerant circuit diagram showing a modified example 1 of the heat pump device 100 according to Embodiment 1. The heat pump device 100 shown in Figure 9 has a hot water storage tank that supplies hot water as a load device 3C. In Figure 9, one load device 3B is the indoor unit, and the other load device 3C is the hot water storage tank. In Figure 9, the case where heating is performed by load device 3B is described as an example, but cooling may also be performed by load device 3B. Also, in Figure 9, as an example, the heating load is assumed to be greater than the hot water supply load.

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

[0058] In the heat pump system 100, when heating is performed by one load device 3B and hot water is supplied by the other load device 3C, the first refrigerant circuit 10, the first heat transfer medium circuit 4, the second refrigerant circuit 20, and the second heat transfer medium circuit 5 are operated. Then, in order to connect the load-side heat exchanger 30 of the heating load device 3B to the first heat transfer medium circuit 4, the first flow path switching device 4a is opened and the first flow path switching device 5a is closed. Similarly, in order to connect the load-side heat exchanger 30 of the hot water supply load device 3C to the second heat transfer medium circuit 5, the first flow path switching device 4a is closed and the first flow path switching device 5a is opened.

[0059] In the first refrigerant circuit 10, the high-temperature, high-pressure gaseous 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 that flows to the first water heat exchanger 11 exchanges heat with the heat transfer medium flowing through the first heat transfer medium circuit 4, condenses and liquefies, is depressurized in 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 that flows to the heat source side heat exchanger 14 exchanges heat with air, evaporates and becomes a gas, passes through the first flow path switching valve 13, and is drawn into the first compressor 12 via the accumulator.

[0060] Meanwhile, the heat transfer medium flowing through the first heat transfer medium circuit 4 is heated by the refrigerant flowing through the first water heat exchanger 11 to become hot water. This hot water then flows through 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 transfer medium then flows to the second water heat exchanger 21, where it is cooled by heat exchange with the refrigerant circulating in the second refrigerant circuit 20, and then flows back into the first water heat exchanger 11.

[0061] In the second refrigerant circuit 20, the high-temperature, high-pressure gaseous refrigerant discharged from the second compressor 23 flows through the second flow path switching valve 24 to the third water heat exchanger 22, where it exchanges heat with the heat transfer medium flowing through the second heat transfer medium circuit 5 and condenses into a liquid. The condensed liquid refrigerant is depressurized in the second expansion mechanism 25 to become a low-pressure gas-liquid two-phase refrigerant, which flows to the second water heat exchanger 21, where it exchanges heat with the heat transfer medium flowing through the first heat transfer medium circuit 4 and evaporates into a gas. The gasified refrigerant passes through the second flow path switching valve 24 and is drawn into the second compressor 23 via the accumulator.

[0062] Meanwhile, the heat transfer medium flowing through the second heat transfer medium circuit 5 is heated by the refrigerant flowing through the third water heat exchanger 22 to become hot water, which is then stored in the storage tank.

[0063] In addition, 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] Figure 10 is a schematic diagram showing a modified example 2 of the heat pump device 100 according to Embodiment 1. The number of heat source units 1, relay units 2, and load devices 3A and 3B is not limited to those described above. As shown in Figure 10, two or more heat source units 1 may be installed. When multiple heat source units 1 are installed, the first heat transfer fluid piping of the heat source units 1 is connected to each other. Also, two or more relay units 2 may be installed. When multiple relay units 2 are installed, the first heat transfer fluid piping of the relay units 2 is connected to each other. Also, three or more load devices 3A and 3B connected to each relay unit 2 may be installed. In this case, all load devices 3A and 3B may be indoor units, or some or all load devices 3A and 3B may be hot water storage tanks for supplying hot water. Also, some load devices 3A and 3B may be directly connected to the heat source unit 1 without going through the relay units 2.

[0065] As described above, the heat pump device 100 according to this embodiment 1 comprises a heat source unit 1, a relay unit 2 connected to the heat source unit 1, and a plurality of load devices 3A and 3B connected to the relay unit 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, 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 devices 3A and 3B are connected by a first heat transfer medium piping 40, forming a first heat transfer medium circuit 4 through which the heat transfer medium circulates.

[0066] Therefore, in the heat pump device 100 according to this embodiment 1, when cooling and heating are performed simultaneously by multiple load devices 3A and 3B, the first refrigerant circuit 10 provided in the heat source unit 1 and the second refrigerant circuit 20 provided in the relay unit 2 can perform cooling or heating, respectively. 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, thus reducing the number of pipes required and alleviating the burden of piping work.

[0067] Embodiment 2. Next, the heat pump device 101 according to this second embodiment will be described with reference to Figures 11 and 12. Figure 11 is a refrigerant circuit diagram of the heat pump device 101 according to this second embodiment. Components identical to those in the heat pump device 100 described in the first embodiment are denoted by the same reference numerals, and their descriptions are omitted as appropriate.

[0068] In the heat pump system 100, when cooling and heating are performed simultaneously by multiple load devices 3A and 3B, the second refrigerant circuit 20 and the second heat transfer fluid circuit 5 are operated, thereby reducing the load on the heat source unit 1 to generate chilled and hot water. As a result, it is no longer necessary to flow all the heat transfer fluid flowing through the first heat transfer fluid circuit 4 into the first water heat exchanger 11.

[0069] Therefore, in the heat pump device 101 according to this second embodiment, the first heat transfer medium circuit 4 is provided with a bypass flow path 7 and a flow rate adjustment device 8. The bypass flow path 7 connects the first heat transfer medium piping 40 between the first water heat exchanger 11 and the second water heat exchanger 21, and the first heat transfer medium piping 40 between the first water heat exchanger 11 and the load-side heat exchanger 30. The flow rate adjustment device 8 adjusts the flow rate of the heat transfer medium flowing into the first water heat exchanger 11 and the flow rate of the heat transfer medium flowing into the outlet side of the first water heat exchanger 11 via the bypass flow path 7. The flow rate adjustment device 8 has a first flow rate adjustment 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 adjustment 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 transfer 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 composed of, for example, two-way valves that can control the valve opening (opening area). The first flow control valve 8a controls the flow rate of the heat transfer medium flowing into the first water heat exchanger 11 by adjusting its opening. The second flow control valve 8b controls the flow rate of the heat transfer medium flowing into the bypass flow path 7 by adjusting its opening. The first flow control valve 8a and the second flow control valve 8b are controlled by the control device 6.

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

[0072] As shown in Figure 12, when 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, so that 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 0%.

[0073] On the other hand, when cooling and heating are performed simultaneously in multiple 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 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 reduces the flow rate V2 of the heat medium flowing into the heat source unit 1, thereby increasing the heat exchange efficiency.

[0074] Furthermore, if the cooling and heating loads in load devices 3A and 3B remain unchanged (point A in Figure 12), the first flow control valve 8a is fully closed and the second flow control valve 8b is fully opened to set the flow rate V1 in the bypass channel 7 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] Furthermore, although the bypass channel 7 is provided in the relay unit 2 in the illustrated example, it may also be provided in the heat source unit 1. In addition, the heat pump device 101 according to Embodiment 2 may be configured as a storage tank for supplying hot water as a load device, as shown in Figure 9.

[0076] Embodiment 3. Next, the heat pump device 102 according to this third embodiment 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 this third embodiment. Note that components identical to those of the heat pump device 100 described in the first embodiment are denoted by the same reference numerals, and their descriptions are omitted as appropriate.

[0077] In the heat pump device 102 according to this third embodiment, the piping in the first water heat exchanger 11 is configured such that the refrigerant circulating in the first refrigerant circuit 10 and the heat transfer medium circulating in the first heat transfer medium circuit 4 flow in opposite directions, thereby increasing the heat exchange rate in the first water heat exchanger 11 and improving energy efficiency. The heat pump device 102 according to this third embodiment is particularly effective when using a non-azeotropic mixed refrigerant with different boiling and dew points, as it can reduce the temperature difference between the refrigerant and water in both the refrigerant condensation process (heating the water) and the refrigerant evaporation process (cooling the water), thereby increasing system efficiency.

[0078] As shown in Figure 13, the first heat transfer medium circuit 4 of the heat pump device 102 is provided with a second flow path switching device 9 that reverses the flow of the heat transfer medium into the first water heat exchanger 11. The second flow path switching device 9 includes a first bypass pipe 90, a second bypass pipe 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 pipe 90 has its first inlet end 90a connected to the first heat transfer medium pipe 40 between the first water heat exchanger 11 and the second water heat exchanger 21, and its first outlet end 90b connected to the first heat transfer medium pipe 40 between the first water heat exchanger 11 and load devices 3A and 3B. The second bypass pipe 91 has its second inlet end 91a connected to the first heat transfer medium pipe 40 between the first water heat exchanger 11 and the first inlet end 90a of the first bypass pipe 90, and its second outlet end 91b connected to the first heat transfer medium pipe 40 between the first outlet end 90b of the first bypass pipe 90 and load devices 3A and 3B.

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

[0081] Figure 14 is a refrigerant circuit diagram for a heat pump device 102 according to Embodiment 3, when hot water is produced in the first heat transfer medium circuit 4. The white color indicated by reference numerals 92 and 95 indicates that the valves are open. The black color indicated by reference numerals 93 and 94 indicates that the valves are closed. In the heat pump device 102, as shown in Figure 14, when hot water is produced in the first heat transfer 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 transfer medium flowing through the first heat transfer medium circuit 4 flows from the second water heat exchanger 21 to the first water heat exchanger 11, is heated by the refrigerant flowing through the first water heat exchanger 11 to become hot water, and then 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, the high-temperature, high-pressure gaseous 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. In other words, in the first water heat exchanger 11, the refrigerant circulating in the first refrigerant circuit 10 and the heat transfer medium circulating in the first heat transfer medium circuit 4 flow in opposite directions.

[0082] Figure 15 is a refrigerant circuit diagram for a heat pump device 100 according to Embodiment 3, when chilled water is produced in the first heat transfer medium circuit 4. The white color indicated by reference numerals 93 and 94 indicates that the valves are open. The black color indicated by reference numerals 92 and 95 indicates that the valves are closed. In the heat pump device 102, as shown in Figure 15, when chilled water is produced in the first heat transfer 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 transfer medium flowing through the first heat transfer 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 transfer medium that has flowed to the first water heat exchanger 11 is cooled by the refrigerant flowing through the first water heat exchanger 11 to become chilled water, which then flows to the second bypass piping 91 and then to 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, the high-temperature, high-pressure gaseous 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 air and condenses into a liquid. The condensed liquid refrigerant is then depressurized in the first expansion mechanism 15 to become a low-pressure gas-liquid two-phase refrigerant, which flows to the first water heat exchanger 11. In other words, in the first water heat exchanger 11, the refrigerant circulating in the first refrigerant circuit 10 and the heat transfer medium circulating in the first heat transfer medium circuit 4 flow in opposite directions.

[0083] As described above, in the heat pump device 102 according to this embodiment 3, in the first water heat exchanger 11, the refrigerant circulating in the first refrigerant circuit 10 and the heat transfer medium circulating in the first heat transfer medium circuit 4 are in a counterflow, so the heat exchange rate can be increased and energy saving can be improved.

[0084] Although the heat pump devices (100-102) have been described above based on the embodiments, the heat pump devices (100-102) are not limited to the configurations of the embodiments described above. The configurations of the heat pump devices (100-102) described above are 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 changes and application variations that are normally performed by those skilled in the art, without departing from the technical concept. [Explanation of symbols]

[0085] 1 Heat source unit, 2 Repeater unit, 3A, 3B Load device, 4 First heat transfer fluid circuit, 4a First flow path switching device, 5 Second heat transfer fluid circuit, 5a First flow path switching device, 6 Control device, 7 Bypass flow path, 8 Flow rate adjustment device, 8a First flow rate adjustment valve, 8b Second flow rate adjustment 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 transfer fluid piping, 41 First pump, 50 Second heat transfer fluid 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 shut-off valve, 93 Second shut-off valve, 94 Third shut-off valve, 95 Fourth shut-off valve, 100, 101, 102 Heat pump system, 200 Building.

Claims

1. A heat pump system comprising 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 includes 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 includes a second refrigerant circuit through which the refrigerant circulates, a second water heat exchanger that exchanges heat with the second refrigerant circuit, and a third 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 transfer medium piping, forming a first heat transfer medium circuit through which the heat transfer medium circulates. The third water heat exchanger and the load device are connected by a second heat transfer fluid piping, forming a second heat transfer fluid circuit through which the heat transfer fluid circulates. A heat pump device wherein the first heat transfer medium circuit and the second heat transfer medium circuit are provided with a first flow path switching device that switches the flow path of the heat transfer medium flowing into the load device to the first heat transfer medium circuit or the second heat transfer medium circuit.

2. The first refrigerant circuit is configured such that at least a first compressor, a first flow path switching valve, a heat source side heat exchanger, a first expansion mechanism, and a first water heat exchanger are sequentially connected by refrigerant piping. The heat pump device according to claim 1, wherein the second refrigerant circuit comprises at least a second compressor, a second water heat exchanger, a second expansion mechanism, and a third water heat exchanger, all connected sequentially by refrigerant piping.

3. The first heat transfer medium circuit is provided with a first pump for circulating the heat transfer medium. The second heat transfer medium circuit is provided with a second pump for circulating the heat transfer medium. The heat pump device according to claim 1 or 2, wherein the second pump has a smaller flow rate or head than the first pump.

4. The heat pump apparatus according to claim 3, wherein the first pump is provided in either the heat source unit or the relay unit, or both.

5. The heat pump apparatus according to claim 1 or 2, wherein at least one of the plurality of load devices is an indoor unit having a load-side heat exchanger.

6. The heat pump device according to claim 1 or 2, wherein at least one of the plurality of load devices is a hot water storage tank for storing hot water.

7. The heat pump device according to claim 1 or 2, wherein the amount of refrigerant circulating in the first refrigerant circuit is greater than the amount of refrigerant circulating in the second refrigerant circuit.

8. The first refrigerant circuit is filled with a flammable refrigerant. The heat pump device according to claim 1 or 2, wherein the second refrigerant circuit is filled with a non-flammable or slightly flammable refrigerant.

9. The first heat transfer medium circuit includes a bypass channel connecting the first heat transfer medium piping between the first water heat exchanger and the second water heat exchanger, and the first heat transfer medium piping between the first water heat exchanger and the load device. The heat pump apparatus according to claim 1 or 2, further comprising a flow rate adjustment device for adjusting the flow rate of the heat transfer medium flowing into the first water heat exchanger and the flow rate of the heat transfer medium flowing into the outlet side of the first water heat exchanger via the bypass channel.

10. The heat pump apparatus according to claim 1 or 2, wherein the first heat transfer medium circuit is provided with a second flow path switching device for reversing the flow of the heat transfer medium into the first water heat exchanger.

11. The second flow path switching device is A first bypass pipe has its first inlet end connected to the first heat transfer medium piping between the first heat exchanger and the second heat exchanger, and its first outlet end connected to the first heat transfer medium piping between the first heat exchanger and the load device, A second bypass pipe has its second inlet end connected to the first heat transfer medium pipe between the first water heat exchanger and the first inlet end of the first bypass pipe, and its second outlet end connected to the first heat transfer medium pipe between the first outlet end of the first bypass pipe and the load device, A first on / off valve is provided in the first heat transfer fluid piping between the first inlet end and the second inlet end, A second on-off valve is provided in the first bypass piping, A third on-off valve is provided in the second bypass piping, The heat pump device according to claim 10, further comprising a fourth on-off valve provided in the first heat transfer fluid piping between the first outlet end and the second outlet end.

12. The heat pump apparatus according to claim 1 or 2, wherein a plurality of heat source units are arranged and the first heat transfer fluid pipes are connected to each other.

13. The heat pump apparatus according to claim 1 or 2, wherein a plurality of relay units are arranged and the first heat transfer fluid pipes are connected to each other.

14. A heat pump system comprising 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 includes 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 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 transfer medium piping, forming a first heat transfer medium circuit through which the heat transfer medium circulates. The first heat transfer medium circuit includes a bypass channel connecting the first heat transfer medium piping between the first water heat exchanger and the second water heat exchanger, and the first heat transfer medium piping between the first water heat exchanger and the load device. A heat pump system is provided with a flow rate adjustment device that adjusts the flow rate of the heat transfer medium flowing into the first water heat exchanger and the flow rate of the heat transfer medium flowing into the outlet side of the first water heat exchanger via the bypass flow path.

15. A heat pump system comprising 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 includes 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 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 transfer medium piping, forming a first heat transfer medium circuit through which the heat transfer medium circulates. The first heat transfer medium circuit is provided with a second flow path switching device that reverses the flow of the heat transfer medium flowing into the first water heat exchanger depending on whether the first refrigerant circuit is producing hot water or cold water. The second flow path switching device is A first bypass pipe has its first inlet end connected to the first heat transfer medium piping between the first heat exchanger and the second heat exchanger, and its first outlet end connected to the first heat transfer medium piping between the first heat exchanger and the load device, A second bypass pipe has its second inlet end connected to the first heat transfer medium pipe between the first water heat exchanger and the first inlet end of the first bypass pipe, and its second outlet end connected to the first heat transfer medium pipe between the first outlet end of the first bypass pipe and the load device, A first on / off valve is provided in the first heat transfer fluid piping between the first inlet end and the second inlet end, A second on-off valve is provided in the first bypass piping, A third on-off valve is provided in the second bypass piping, A heat pump device having a fourth on-off valve provided in the first heat transfer fluid piping between the first outlet end and the second outlet end.

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