HEAT PUMP DEVICE

Abstract

A heat pump device comprises a heat source unit, which includes a first refrigerant circuit configured to switch between cooling and heating operation and in which refrigerant circulates, and which includes a first heat transfer fluid heat exchanger configured to perform heat exchange with the first refrigerant circuit; a relay unit configured to switch between cooling and heating operation and which includes a second refrigerant circuit, which is configured to switch between cooling and heating operation and in which refrigerant circulates, and which includes a second heat transfer fluid heat exchanger configured to perform heat exchange with the second refrigerant circuit; a first load device comprising a first load-side heat exchanger; a second load device comprising a second load-side heat exchanger; and a first heat transfer fluid circuit.a second heat transfer circuit in which the first heat transfer fluid heat exchanger and the first load-side heat exchanger are connected by a drain heat transfer fluid line and a return heat transfer fluid line, and in which a heat transfer fluid circulates; a second heat transfer fluid circuit in which the second heat transfer fluid heat exchanger and the second load-side heat exchanger are connected by a heat transfer fluid line, and in which a heat transfer fluid circulates.

Description

Technical field

[0001] The present disclosure relates to a heat pump device. State of the art

[0002] Various heat pump devices using refrigerants and heat transfer fluids have been disclosed to date (see, for example, patent literature 1). For example, patent literature 1 discloses a cold and hot water multi-room air conditioning device comprising two cold and hot water devices and a plurality of indoor units installed on each floor of a building. In this cold and hot water multi-room air conditioning device, each outdoor unit is connected to a plurality of indoor units via cold and hot water lines. One outdoor unit of one of the cold and hot water multi-room air conditioning devices is used for cooling operation, and one outdoor unit of the other cold and hot water multi-room air conditioning device is used for heating operation, thus enabling simultaneous cooling and heating in each indoor unit. List of citations, patent literature

[0003] Patent Literature 1: JPH04-214134A Summary of the invention: Technical problem

[0004] However, in the cold and hot water multi-room air conditioning system described in patent literature 1, two cold and hot water lines are required for circulating cold water, connected to the outdoor unit of one of the cold and hot water multi-room air conditioning systems, and two cold and hot water lines are required for circulating hot water, connected to the outdoor unit of the other cold and hot water multi-room air conditioning system. Therefore, two cold and hot water lines must be installed at each externally located outdoor unit, and due to the large number of cold and hot water lines to be installed, the costs for laying the lines and the effort required for pipework increase, which poses a problem in terms of constructability.

[0005] The heat pump device of the present disclosure was designed to overcome the above-mentioned problems, and its purpose is to provide a heat pump device that reduces line costs and improves manufacturability by reducing the number of heat transfer lines connected to the heat source unit. Solution to the problem

[0006] A heat pump device according to an embodiment of the present disclosure comprises a heat source unit comprising a first refrigerant circuit configured to switch between cooling and heating operation and in which refrigerant circulates, and comprising a first heat transfer medium heat exchanger configured to perform heat exchange with the first refrigerant circuit, a relay unit comprising a second refrigerant circuit configured to switch between cooling and heating operation and in which refrigerant circulates, a second heat transfer medium heat exchanger configured to perform heat exchange with the second refrigerant circuit, a first load device comprising a first load-side heat exchanger, a second load device comprising a second load-side heat exchanger, a first heat transfer medium circuit,in which the first heat transfer fluid heat exchanger and the first load-side heat exchanger are connected by a drain heat transfer fluid line and a return heat transfer fluid line and in which a heat transfer fluid circulates, and comprises a second heat transfer fluid circuit in which the second heat transfer fluid heat exchanger and the second load-side heat exchanger are connected by a heat transfer fluid line and in which a heat transfer fluid circulates. Advantageous effects of the invention

[0007] According to one embodiment of the heat pump device of the present disclosure, when cooling and heating operation is carried out simultaneously on a plurality of load devices, either cooling or heating can be performed for each operation using the first refrigerant circuit in the heat source unit and the second refrigerant circuit in the relay unit. Therefore, the number of heat transfer lines connected to the heat source unit can be limited to two: the discharge heat transfer line and the return heat transfer line. Compared to conventional systems, this reduces the number of lines connected to the heat source unit, thereby lowering line costs and simplifying line design. This, in turn, improves ease of design. Brief description of the drawings [ Fig. 1] Fig. Figure 1 is a refrigerant circuit diagram showing an example of the circuit design of a heat pump device according to embodiment 1. [ Fig. 2] Fig. Figure 2 is a refrigerant cycle diagram showing the flows of the refrigerant and the heat transfer fluid when the heat pump device according to embodiment 1 operates in pure cooling mode. [ Fig. 3] Fig. Figure 3 is a refrigerant cycle diagram showing the flows of the refrigerant and the heat transfer fluid when pure heating operation is carried out in the heat pump device according to embodiment 1. [ Fig. 4] Fig. Figure 4 is a refrigerant cycle diagram showing the flows of the refrigerant and the heat transfer fluid when a main cooling operation is carried out in the heat pump device according to embodiment 1. [ Fig. 5] Fig. Figure 5 is a refrigerant cycle diagram showing the flows of the refrigerant and the heat transfer fluid when a main heating operation is carried out in the heat pump device according to embodiment 1. [ Fig. 6] Fig. Figure 6 is a refrigerant circuit diagram showing an example of the circuit design of the heat pump device according to embodiment 2. Description of the embodiments

[0008] The embodiments of this disclosure are explained below with reference to the drawings. However, this disclosure is not limited to the embodiments described below. Furthermore, the dimensions of the components in the following drawings may differ from those of the actual components. Design 1.

[0009] Fig. Figure 1 is a refrigerant circuit diagram showing an example of the circuit design of a heat pump device 100 according to embodiment 1. As shown in Fig. As shown in Figure 1, the heat pump device 100 according to embodiment 1 comprises a heat source unit 10, a plurality of load devices (four in embodiment 1), a relay unit 30, and a control unit 40. Of the four load devices, three are first load devices 20Aa, 20Ab, and 20Ac for switching between cooling and heating operations, each performing the same operation. One is a second load device 20B for simultaneous cooling and heating operations, performing the same or different operations as the first load devices 20Aa, 20Ab, and 20Ac. The heat pump device 100 has a configuration in which the heat source unit 10 and the three first load devices 20Aa, 20Ab, and 20Ac are connected via two heat transfer lines (a discharge heat transfer line 5a and a return heat transfer line 5b). Additionally, the first three load devices 20Aa, 20Ab and 20Ac are connected in parallel to the heat source unit 10. Even if in Fig. Figure 1 shows three first load devices 20Aa, 20Ab, 20Ac. The number of load devices is not limited to three and can be any number, as long as there is one or more. For example, the heat source unit 10 is an outdoor unit. The first load devices 20Aa, 20Ab, 20Ac and the second load device 20B are, for example, indoor units. The heat source unit 10 is, for example, installed on the roof of a building. The relay unit 30, the first load devices 20Aa, 20Ab, 20Ac and the second load device 20B are, for example, installed inside the building. The heat source 10, the first load devices 20Aa, 20Ab, 20Ac, the second load device 20B and the relay unit 30 are controlled by the controller 40.

[0010] Furthermore, the heat pump device 100 comprises a first refrigerant circuit 1 and a second refrigerant circuit 2 in which refrigerant circulates, as well as a first heat transfer circuit 3 and a second heat transfer circuit 4 in which a heat transfer fluid circulates. The first refrigerant circuit 1, for example, has a configuration in which a first compressor 11, a first flow switching device 12, a heat source-side heat exchanger 13, a first expansion device 15, a first heat transfer fluid heat exchanger 16, and an accumulator 17 are cyclically connected to one another in that order via a refrigerant line.The second refrigerant circuit 2, for example, has a configuration in which a second compressor 31, a second flow switching device 32, a third heat transfer fluid heat exchanger 33, a second expansion device 34, and a second heat transfer fluid heat exchanger 35 are cyclically connected in that order via a refrigerant line. The first heat transfer fluid circuit 3, for example, has a configuration in which a first pump 18, the first heat transfer fluid heat exchanger 16, the third heat transfer fluid heat exchanger 33, and the first load devices 20Aa, 20Ab, 20Ac are cyclically connected in that order via a discharge heat transfer fluid line 5a and a return heat transfer fluid line 5b. The second heat transfer fluid circuit 4, for example, has a configuration in which a second pump 36, the second heat transfer fluid heat exchanger 35, and the second load device 20B are cyclically connected in that order via a heat transfer fluid line.In embodiment 1, the first refrigerant circuit 1 is installed in the heat source unit 10, while the second refrigerant circuit 2 is installed in the relay unit 30.

[0011] The refrigerant charged into the first refrigerant circuit 1 and the second refrigerant circuit 2 can be, for example, a single-component refrigerant such as R1234yf, R1234ze, R32, and R290; a blend of two or more of these; a blend of one of these refrigerants with another; a blend containing R1132(E); or a blend containing R1123. Furthermore, blend refrigerants such as R516A, R445A, R444A, R454C, R444B, R454A, R455A, R457A, R459B, R452B, R454B, R447B, R447A, R446A, and R459A can be used. The refrigerant filled into the first refrigerant circuit 1 and the refrigerant filled into the second refrigerant circuit 2 can be the same or different.

[0012] Examples of heat transfer fluids used in the first heat transfer circuit 3 and the second heat transfer circuit 4 are water and brine. Additionally, the heat transfer fluid used in the first heat transfer circuit 3 and the heat transfer fluid used in the second heat transfer circuit 4 can be the same or different. [Heat source unit 10]

[0013] The heat source unit 10 comprises the first compressor 11, the first flow switching device 12, the heat source-side heat exchanger 13, the heat source-side fan 14, the first expansion device 15, the first heat transfer fluid heat exchanger 16, the accumulator 17, the first pump 18, and an opening and closing valve 19. The first compressor 11 draws in the refrigerant and compresses it to a state of high temperature and high pressure. The first compressor 11 may, for example, be a variable-speed inverter compressor. The first compressor 11 used may be of the low-pressure housing type. The low-pressure housing compressor has a compression chamber inside a sealed container that creates a low-pressure refrigerant atmosphere. It draws in the low-pressure refrigerant inside the sealed container and compresses it.The first flow switching device 12 is, for example, a four-way valve and can switch between cooling and heating operation by redirecting the refrigerant flow. Alternatively, the first flow switching device could also be formed by a combination of two-way and three-way valves. The heat source-side heat exchanger 13 can serve as an evaporator or condenser, which performs the heat exchange between the air and the refrigerant to evaporate and vaporize or condense and liquefy the refrigerant. The heat source-side heat exchanger 13 serves as an evaporator during heating operation and as a condenser during cooling operation. The heat source-side fan 14 is installed near the heat source-side heat exchanger 13 and supplies it with air. The first expansion device 15 reduces the pressure and expands the refrigerant.The first expansion valve can, for example, be an electronic expansion valve that can adjust the opening degree. By adjusting the opening degree, it regulates the pressure of the refrigerant flowing into the heat source heat exchanger 13 during heating operation and the pressure of the refrigerant flowing into the first heat transfer fluid heat exchanger 16 during cooling operation. The first heat transfer fluid heat exchanger 16 has a heat transfer section for the refrigerant and another heat transfer section for the heat transfer fluid, which facilitates heat exchange between the refrigerant and the heat transfer fluid. During heating operation, the first heat transfer fluid heat exchanger 16 acts as a condenser, allowing the refrigerant to heat the heat transfer fluid by radiating heat from the refrigerant.During cooling operation, the first heat transfer fluid heat exchanger acts as an evaporator, allowing the refrigerant to cool the heat transfer fluid by absorbing heat. The accumulator 17, located on the suction side of the first compressor 11, stores excess refrigerant that arises due to the difference between the required refrigerant quantity for heating and cooling operation or due to temporary changes in operation. The first pump 18 is a heat transfer fluid pump that circulates the heat transfer fluid into the second heat transfer fluid circuit 4. By varying the speed of its integrated motor (not shown), the first pump can adjust the flow rate of the heat transfer fluid. The open / close valve 19, designed, for example, as a two-way valve, can control the flow of the heat transfer fluid by opening and closing it. [First load devices 20Aa, 20Ab, 20Ac]

[0014] The first load devices 20Aa, 20Ab, and 20Ac each serve to supply heat from the heat source unit 10 for the cooling or heating load and to perform air conditioning or heating of the room to be air-conditioned. The first load device 20Aa comprises a first load-side heat exchanger 21Aa and a first load-side fan 22Aa. The first load device 20Ab comprises a first load-side heat exchanger 21Ab and a first load-side fan 22Ab. The first load device 20Ac comprises a first load-side heat exchanger 21Ac and a first load-side fan 22Ac.

[0015] In the following explanation, the first load device 20Aa, the first load device 20Ab, and the first load device 20Ac will, unless there is a particular need to distinguish between them, simply be referred to as "the first load device 20A," where appropriate. Furthermore, the first load-side heat exchanger 21Aa, the first load-side heat exchanger 21Ab, and the first load-side heat exchanger 21Ac have the same configuration, and the first load-side fan 22Aa, the first load-side fan 22Ab, and the first load-side fan 22Ac also have the same configuration. Therefore, the first load-side heat exchanger 21Aa and the first load-side fan 22Aa will be used as examples in the following.

[0016] The first load-side heat exchanger 21Aa performs heat exchange between the indoor air and the heat transfer fluid. Specifically, during cooling operation, the first load-side heat exchanger 21Aa cools the indoor air by allowing the heat transfer fluid to absorb heat. Additionally, during heating operation, the first load-side heat exchanger 21Aa heats the indoor air by allowing the heat transfer fluid to release heat. It should be noted that the first load-side heat exchanger 21Aa is installed so that it is supplied with indoor air by the nearby first load-side fan 22Aa. [Second load device 20B]

[0017] The second load device 20B supplies heat from the relay unit 30 to the cooling or heating load and performs either a cooling or a heating operation for the room to be air-conditioned. The second load device 20B comprises a second load-side heat exchanger 21B and a second load-side fan 22B.

[0018] The second load-side heat exchanger 21B performs the heat exchange between the indoor air and the heat transfer fluid. Specifically, during cooling operation, the second load-side heat exchanger 21B cools the indoor air by allowing the heat transfer fluid to absorb heat. Additionally, during heating operation, the second load-side heat exchanger 21B heats the indoor air by allowing the heat transfer fluid to release heat. It should be noted that the second load-side heat exchanger 21B is installed so that it is supplied with indoor air by the nearby second load-side fan 22B. [Relay Unit 30]

[0019] The relay unit 30 comprises the second compressor 31, the second flow switching device 32, the third heat transfer fluid heat exchanger 33, the second expansion device 34, the second heat transfer fluid heat exchanger 35, and the second pump 36. The second compressor 31 draws in the refrigerant, compresses it, and brings it to a state of high temperature and high pressure. The second compressor 31 can, for example, be a variable-speed inverter compressor. The second compressor 31 can, for example, have a low-pressure housing design. The compressor with a low-pressure housing design has a compression chamber inside a sealed container, which creates an atmosphere of low refrigerant pressure. It draws in the low-pressure refrigerant inside the sealed container and compresses it.The second flow switching device 32, which is, for example, a four-way valve, is configured to switch between cooling and heating operation by changing the direction of the refrigerant flow. Instead of a four-way valve, a combination of a two-way and a three-way valve can also be used for the second flow switching device 32. The third heat transfer fluid heat exchanger 33 has a heat transfer section for passing refrigerant and another heat transfer section for passing a heat transfer fluid, which facilitates heat exchange between the refrigerant and the heat transfer fluid. During cooling operation, the third heat transfer fluid heat exchanger 33 acts as a condenser, allowing the refrigerant to release heat to heat the heat transfer fluid. Conversely, during heating operation, the third heat transfer fluid heat exchanger 33 acts as an evaporator, allowing the refrigerant to absorb heat to cool the heat transfer fluid.The second expansion device 34 reduces the pressure and expands the refrigerant. The second expansion device 34 is, for example, an electronic expansion valve with an adjustable opening degree. By adjusting the opening degree, it controls the pressure of the refrigerant flowing into the third heat transfer fluid heat exchanger 33 during heating operation and the pressure of the refrigerant flowing into the second heat transfer fluid heat exchanger 35 during cooling operation. The second heat transfer fluid heat exchanger 35 has one heat transfer section for passing refrigerant and another heat transfer section for passing a heat transfer fluid, thereby facilitating heat exchange between the refrigerant and the heat transfer fluid.The second heat transfer fluid heat exchanger 35 acts as a condenser during heating operation, causing the refrigerant to transfer heat to the heat transfer fluid and thus heat it. During cooling operation, it acts as an evaporator, causing the refrigerant to absorb heat from the heat transfer fluid and thus cool it. The second pump 36 is a heat transfer fluid pump that circulates the heat transfer fluid into the first heat transfer fluid circuit 3. The second pump 36 can vary the delivery rate, which is the volume of heat transfer fluid being pumped, by changing the speed of its built-in motor (not shown in the figure) within a specific range. [Control 40]

[0020] The controller 40 controls the entire heat pump device 100. For example, depending on the operating processes of the heat pump device 100, the controller 40 controls the first refrigerant circuit 1, the second refrigerant circuit 2, the first heat transfer circuit 3, and the second heat transfer circuit 4. The various functions of the controller 40 are achieved by executing software on computing devices such as microcomputers or can consist of hardware such as circuit devices that implement various functions.

[0021] Next, the operating behavior of the heat pump device 100 during various processes is described. The operating modes of the heat pump device 100 comprise four types: pure cooling operation, pure heating operation, primary cooling operation, and primary heating operation.

[0022] "Pure cooling operation" refers to an operating mode in which only cooling operation is possible in the first load device 20A and the second load device 20B; that is, the state in which the first load device 20A and the second load device 20B perform cooling operation. "Pure heating operation" refers to an operating mode in which only heating operation is possible at the first load device 20A and the second load device 20B; that is, the state in which the first load device 20A and the second load device 20B perform heating operation. "Main cooling operation" refers to an operating mode in which the cooling load exceeds the heating load with simultaneous cooling and heating operation, in which the first load device 20A performs cooling operation and the second load device 20B performs heating operation.“Main heating operation” refers to an operating mode in which the heating load exceeds the cooling load during simultaneous cooling and heating operation, with the first load device 20A performing a heating operation and the second load device 20B performing a cooling operation. [Pure cooling operation]

[0023] First, with reference to Fig. 2 the pure cooling operation of the heat pump device 100 is explained. Fig. Figure 2 is a refrigerant circuit diagram showing the flows of the refrigerant and the heat transfer fluid when the heat pump device according to embodiment 1 is operating in pure cooling mode. Furthermore, the diagrams shown in Figure 2 illustrate the flow patterns of the refrigerant and the heat transfer fluid when the heat pump device according to embodiment 1 is operating in pure cooling mode. Fig. The solid arrows shown in Figure 2 indicate the flow of the refrigerant, while the hollow arrows indicate the flow of the heat transfer fluid.

[0024] In the first refrigerant circuit 1, the high-temperature, high-pressure gaseous refrigerant discharged from the first compressor 11 flows through the first flow reversing device 12 to the heat source-side heat exchanger 13, where it undergoes heat exchange with the outside air to condense and liquefy. The condensed and liquefied refrigerant is depressurized by the first expansion device 15, becoming a low-pressure, two-phase gas-liquid refrigerant, and flows into the first heat transfer fluid heat exchanger 16, where it exchanges heat with the heat transfer fluid flowing in the first heat transfer fluid circuit 3 to evaporate and vaporize. The evaporated and vaporized refrigerant flows through the first flow reversing device 12 and is drawn back into the first compressor 11 via the accumulator 17.

[0025] In the second refrigerant circuit 2, the hot, high-pressure gaseous refrigerant exiting the second compressor 31 flows through the second flow reversing device 32 to the third heat transfer fluid heat exchanger 33, where it exchanges heat with the heat transfer fluid flowing in the first heat transfer fluid circuit 3 to condense and liquefy. The condensed, liquefied refrigerant is depressurized in the second expansion device 34, becoming a low-pressure, two-phase gas-liquid refrigerant, and flows into the second heat transfer fluid heat exchanger 35, where it exchanges heat with the heat transfer fluid flowing in the second heat transfer fluid circuit 4 to evaporate and vaporize. The evaporated and vaporized refrigerant flows through the second flow reversing device 32 and is drawn back into the second compressor 31.

[0026] In the first heat transfer circuit 3, the heat transfer fluid pumped by the first pump 18 is cooled by the refrigerant flowing through the first heat transfer fluid heat exchanger 16, becoming cold water. The heat transfer fluid then flows into the first load-side heat exchangers 21Aa, 21Ab, and 21Ac, where it exchanges heat with the indoor air and is thereby heated, while the indoor air is simultaneously cooled. The heated heat transfer fluid then flows into the third heat transfer fluid heat exchanger 33, where it is further heated by heat exchange with the refrigerant flowing through the second refrigerant circuit 2. The heated heat transfer fluid is then drawn back into the first pump 18.

[0027] In the second heat transfer circuit 4, the heat transfer fluid pumped by the second pump 36 is cooled by the refrigerant flowing through the second heat transfer fluid heat exchanger 35 and becomes cold water. The heat transfer fluid then flows into the second load-side heat exchanger 21B, where it exchanges heat with the interior air to warm it and simultaneously cool the interior air. The heated heat transfer fluid is then drawn back in by the second pump 36. [Pure heating operation]

[0028] The following describes the pure heating operation of the heat pump device 100 with reference to Fig. 3 described. Fig. Figure 3 is a refrigerant circuit diagram showing the flows of the refrigerant and the heat transfer fluid when the heat pump device 100 according to embodiment 1 is operating in pure heating mode. It should be noted that the Fig. The three solid arrows shown indicate the flow of the refrigerant and the hollow arrows indicate the flow of the heat transfer fluid.

[0029] In the first refrigerant circuit 1, the high-temperature, high-pressure gaseous refrigerant discharged from the first compressor 11 flows through the first flow switching device 12 and into the first heat transfer fluid heat exchanger 16. The refrigerant flowing into the first heat transfer fluid heat exchanger 16 exchanges heat with the heat transfer fluid flowing through the first heat transfer fluid circuit 3, condenses and liquefies, and is reduced in pressure by the first expansion device 15, thereby becoming a low-pressure, two-phase gas-liquid refrigerant, which then flows to the heat source-side heat exchanger 13. The two-phase gas-liquid refrigerant flowing into the heat source-side heat exchanger 13 exchanges heat with the outside air to evaporate and gasify, then flows through the first flow switching device 12 and is drawn into the first compressor 11 via the accumulator 17.

[0030] In the second refrigerant circuit 2, the high-temperature, high-pressure gaseous refrigerant exiting the second compressor 31 flows through the second flow reversing device 32 and into the second heat transfer fluid heat exchanger 35, where it exchanges heat with the heat transfer fluid flowing in the second heat transfer fluid circuit 4 to condense and liquefy. The condensed and liquefied refrigerant is depressurized by the second expansion device 34, becoming a low-pressure, two-phase gas-liquid refrigerant, and then flows into the third heat transfer fluid heat exchanger 33, where it exchanges heat with the heat transfer fluid flowing through the first heat transfer fluid circuit 3 to evaporate and vaporize. The evaporated and vaporized refrigerant flows through the second flow reversing device 32 and is drawn back into the second compressor 31.

[0031] In the first heat transfer circuit 3, the heat transfer fluid pumped by the first pump 18 is converted into hot water after being heated by the refrigerant flowing through the first heat transfer heat exchanger 16. It then flows into the first load-side heat exchangers 21Aa, 21Ab, 21Ac, where it releases heat to the indoor air, is cooled, and in turn heats the indoor air. The cooled heat transfer fluid flows into the third heat transfer heat exchanger 33 and exchanges heat with the refrigerant flowing in the second refrigerant circuit 2 to be cooled. The cooled heat transfer fluid is then drawn back into the first pump 18.

[0032] In the second heat transfer circuit 4, the heat transfer fluid pumped by the second pump 36 is converted into hot water after being heated by the refrigerant flowing through the second heat transfer fluid heat exchanger 35. This hot water flows into the second load-side heat exchanger 21B, where it releases heat to the indoor air in the room and is cooled, while the indoor air is heated. The cooled heat transfer fluid is then drawn in again by the second pump 36. [Main cooling operation]

[0033] The following refers to Fig. 4 describes the case in which the cooling operation is carried out by the first load device 20A, the heating operation by the second load device 20B and a main cooling operation with a large cooling load. Fig. Figure 4 is a refrigerant circuit diagram showing the flows of the refrigerant and the heat transfer fluid when the main cooling operation is carried out in the heat pump device 100 according to embodiment 1. It should be noted that the in Fig. The solid arrows shown in Figure 4 represent the flow of the refrigerant, and the dashed arrows represent the flow of the heat transfer fluid.

[0034] In the first refrigerant circuit 1, the high-temperature, high-pressure gaseous refrigerant discharged from the first compressor 11 flows through the first flow reversing device 12 and into the heat source-side heat exchanger 13, where it exchanges heat with the outside air to condense and liquefy. The condensed and liquefied refrigerant is depressurized by the first expansion device 15 and becomes a low-pressure, two-phase gas-liquid refrigerant, which then flows into the first heat transfer fluid heat exchanger 16 and exchanges heat with the heat transfer fluid flowing through the first heat transfer fluid circuit 3 to evaporate and vaporize. The evaporated and vaporized refrigerant flows through the first flow reversing device 12 and is drawn back into the first compressor 11 via the accumulator 17.

[0035] In the second refrigerant circuit 2, the high-temperature, high-pressure gaseous refrigerant exiting the second compressor 31 flows through the second flow reversing device 32 to the second heat transfer fluid heat exchanger 35, where it exchanges heat with the heat transfer fluid flowing in the second heat transfer fluid circuit 4 to condense and liquefy. The condensed and liquefied refrigerant is then depressurized by the second expansion device 34 and becomes a low-pressure, two-phase gaseous-liquid refrigerant, which flows into the third heat transfer fluid heat exchanger 33. There, it exchanges heat with the heat transfer fluid flowing through the first heat transfer fluid circuit 3 to evaporate and gasify. The evaporated and gaseous refrigerant flows through the second flow reversing device 32 and is drawn back into the second compressor 31.

[0036] In the first heat transfer circuit 3, the heat transfer fluid pumped by the first pump 18 is cooled by the refrigerant flowing through the first heat transfer heat exchanger 16 and converted into cold water. This cold water then flows into the first load-side heat exchangers 21Aa, 21Ab, and 21Ac, where it exchanges heat with the indoor air and is thereby heated while simultaneously cooling the air. The heated heat transfer fluid then flows into the third heat transfer heat exchanger 33, where it exchanges heat with the refrigerant flowing through the second refrigerant circuit 2 and is thereby cooled. The cooled heat transfer fluid is then drawn back into the first pump 18.

[0037] In the second heat transfer circuit 4, the heat transfer fluid pumped by the second pump 36 is heated by the refrigerant flowing through the second heat transfer fluid heat exchanger 35 and becomes hot water. This hot water then flows into the second load-side heat exchanger 21B, where it exchanges heat with the indoor air to be cooled, while the indoor air is heated. The cooled heat transfer fluid is then drawn back into the second pump 36. [Main heating operation]

[0038] With reference to Fig. Section 5 below describes the case in which heating operation is carried out by the first load device 20A and cooling operation by the second load device 20B, and then explains the case in which heating operation with high load, referred to as main heating operation. Fig. Figure 5 is a refrigerant circuit diagram showing the flows of the refrigerant and the heat transfer fluid when the main heating operation is carried out in the heat pump device 100 according to embodiment 1. The Fig. The solid arrows shown in the diagram indicate the flow of the refrigerant, while the hollow arrows indicate the flow of the heat transfer fluid.

[0039] In the first refrigerant circuit 1, the high-temperature, high-pressure gaseous refrigerant discharged from the first compressor 11 flows through the first flow switching device 12 and into the first heat transfer fluid heat exchanger 16. The refrigerant flowing into the first heat transfer fluid heat exchanger 16 exchanges heat with the heat transfer fluid flowing through the first heat transfer fluid circuit 3 in order to condense and liquefy. Subsequently, the condensed and liquefied refrigerant is depressurized by the first expansion device 15 to become a low-pressure, two-phase gas-liquid refrigerant, which flows into the heat source-side heat exchanger 13. The two-phase gas-liquid refrigerant flowing into the heat source-side heat exchanger 13 exchanges heat with outside air to be evaporated and gasified, then flows through the first flow switching device 12 and is drawn into the first compressor 11 via the accumulator 17.

[0040] In the second refrigerant circuit 2, the high-temperature, high-pressure gaseous refrigerant discharged from the second compressor 31 flows through the second flow switching device 32 and into the third heat transfer fluid heat exchanger 33. Here, the high-temperature, high-pressure gaseous refrigerant exchanges heat with the heat transfer fluid flowing through the first heat transfer fluid circuit 3 to condense and liquefy. The condensed and liquefied refrigerant is depressurized by the second expansion device 34 and becomes a low-pressure, two-phase gas-liquid refrigerant. The low-pressure, two-phase gas-liquid refrigerant then flows into the second heat transfer fluid heat exchanger 35 and exchanges heat with the heat transfer fluid flowing through the second heat transfer fluid circuit 4 to evaporate and vaporize. The evaporated and gasified refrigerant flows through the second flow switching device 32 and is drawn back into the second compressor 31.

[0041] In the first heat transfer circuit 3, the heat transfer fluid pumped by the first pump 18 is heated by the refrigerant flowing through the first heat transfer fluid heat exchanger 16, becoming hot water. This hot water then flows through the first load-side heat exchangers 21Aa, 21Ab, 21Ac, where it exchanges heat with the indoor air in the room and is thereby cooled while simultaneously heating the indoor air. The cooled heat transfer fluid then flows into the third heat transfer fluid heat exchanger 33, where it is heated by heat exchange with the refrigerant flowing through the second refrigerant circuit 2. The heated heat transfer fluid is then drawn back into the first pump 18.

[0042] In the second heat transfer circuit 4, the heat transfer fluid pumped by the second pump 36 is cooled by the refrigerant flowing through the second heat transfer fluid heat exchanger 35 and becomes cold water. It then flows into the second load-side heat exchanger 21B, where it exchanges heat with the indoor air of the room to be heated, while the indoor air is cooled. The heated heat transfer fluid is then drawn back into the second pump 36.

[0043] It follows from the foregoing that in the heat pump device 100 according to embodiment 1, when both cooling and heating operations are carried out simultaneously with multiple load devices, a first refrigerant circuit 1, provided at the heat source unit 10, and a second refrigerant circuit 2, provided at the relay unit 30, can perform either the cooling or the heating operation individually. Therefore, the number of heat transfer lines connected to the heat source unit 10 can be reduced to two: the discharge heat transfer line 5a and the return heat transfer line 5b. Consequently, this reduction in the number of lines connected to the heat source unit 10, compared to conventional systems, can lower line costs, reduce the effort required for line construction, and improve ease of design.

[0044] As described above, the heat pump device 100 according to embodiment 1 comprises the heat source unit 10, which has the first refrigerant circuit 1 in which the refrigerant circulates and which is switchable between cooling and heating operation, and the first heat transfer medium heat exchanger 16, which exchanges heat with the first refrigerant circuit 1. The heat pump device 100 also comprises a relay unit 30, which includes a second refrigerant circuit 2, which is switchable between cooling and heating operation and in which refrigerant circulates, and a second heat transfer medium heat exchanger 35, which exchanges heat with the second refrigerant circuit 2. The heat pump device 100 also includes a first load device 20Aa, 20Ab and 20Ac, which have first load-side heat exchangers 21Aa, 21Ab and 21Ac, and a second load device 20B, which includes a second load-side heat exchanger 21B.The heat pump device 100 also comprises a first heat transfer circuit 3 in which a heat transfer fluid circulates and in which the first heat transfer fluid heat exchanger 16 and the first load-side heat exchangers 21Aa, 21Ab and 21Ac are connected by the discharge heat transfer fluid line 5a and a return heat transfer fluid line 5b. The heat pump device 100 also comprises a second heat transfer circuit 4, and the second heat transfer fluid heat exchanger 35 and the second load-side heat exchanger 21B are connected by a heat transfer fluid line in which a heat transfer fluid circulates.

[0045] According to embodiment 1 of the heat pump device 100, when cooling and heating operations are carried out simultaneously on multiple load devices, either the cooling or the heating operation can be performed using the first refrigerant circuit 1 in the heat source unit 10 and the second refrigerant circuit 2 in the relay unit 30 for each operation. Therefore, the number of heat transfer lines connected to the heat source unit 10 can be limited to two: the discharge heat transfer line 5a and the return heat transfer line 5b. This reduces the number of lines connected to the heat source unit 10 compared to conventional systems, thereby lowering line costs and simplifying line design. This, in turn, improves ease of design. Design 2.

[0046] The following describes embodiment 2. Explanations of parts that overlap with embodiment 1 are omitted, and parts that are identical or equivalent to those of embodiment 1 are provided with the same reference numerals.

[0047] Fig. Figure 6 is a refrigerant circuit diagram showing an example of the circuit design of a heat pump device 100A according to embodiment 2. In the heat pump device 100A according to embodiment 2, as shown in Fig. Figure 6 shows no relay unit 30, and in addition to the second refrigerant circuit 2, the second heat transfer circuit 4 is provided in the second load device 20B1 for simultaneous heating and cooling operation. The remaining configuration corresponds to the heat pump device 100A according to embodiment 1, so further explanation is unnecessary.

[0048] As described above, the heat pump device 100 according to embodiment 2 comprises a heat source unit 10, which includes a first refrigerant circuit 1 that is switchable between cooling and heating operation and in which refrigerant circulates, and a first heat transfer fluid heat exchanger 16 that exchanges heat with the first refrigerant circuit 1. The heat pump device 100 also includes the first load devices 20Aa, 20Ab, and 20Ac, which have the first load-side heat exchangers 21Aa, 21Ab, and 21Ac. The heat pump device 100 also includes a first heat transfer fluid circuit 3 in which the first heat transfer fluid heat exchanger 16 and the first load-side heat exchangers 21Aa, 21Ab, and 21Ac are connected by the outgoing heat transfer fluid line 5a and the return heat transfer fluid line 5b, and in which a heat transfer fluid circulates.The heat pump device 100 also includes the second load device 20B1, which includes the second refrigerant circuit 2, which is switchable between cooling and heating operation and in which refrigerant circulates, the second heat transfer fluid heat exchanger 35, which is configured to exchange heat with the second refrigerant circuit 2, and the second heat transfer fluid circuit 4, in which the second heat transfer fluid heat exchanger 35 and the second load-side heat exchanger 21B are connected by the heat transfer fluid line and in which the heat transfer fluid circulates.

[0049] According to the heat pump device 100A of embodiment 2, when cooling and heating operation are carried out simultaneously on several load devices, either the cooling operation or the heating operation can be carried out with the first refrigerant circuit 1 in the heat source unit 10 and the second refrigerant circuit 2 in the relay unit 30 for each operation. This allows the number of heat transfer lines connected to the heat source unit 10 to be reduced to two, namely the discharge heat transfer line 5a and the return heat transfer line 5b. This lowers the line costs and reduces the complexity of the line design. This, in turn, improves the ease of design. Reference symbol list

[0050] 1: First refrigerant circuit, 2: Second refrigerant circuit, 3: First heat transfer circuit, 4: Second heat transfer circuit, 5a: Outlet heat transfer line, 5b: Return heat transfer line, 10: Heat source unit, 11: First compressor, 12: First flow diverter, 13: Heat source-side heat exchanger, 14: Heat source-side fan, 15: First expansion device, 16: First heat transfer fluid heat exchanger, 17: Accumulator, 18: First pump, 19: Opening and closing valve, 20A: First load device, 20Aa: First load device, 20Ab: First load device, 20Ac: First load device, 20B: Second load device, 20B1: Second load device, 21Aa: First load-side heat exchanger, 21Ab: First load-side heat exchanger, 21Ac: First load-side heat exchanger 21B: second load-side heat exchanger, 22Aa: first load-side fan, 22Ab: first load-side fan, 22Ac: first load-side fan, 22B: second load-side fan, 30: relay unit,31: second compressor, 32: second flow switching device, 33: third heat transfer fluid heat exchanger, 34: second expansion device, 35: second heat transfer fluid heat exchanger, 36: second pump, 40: control unit, 100: heat pump device QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] JPH04-214134A

[0003]

Claims

[1] Heat pump device comprising: a heat source unit comprising a first refrigerant circuit designed to switch between cooling and heating operation and in which refrigerant circulates, and comprising a first heat transfer medium heat exchanger designed to perform heat exchange with the first refrigerant circuit, a relay unit configured to switch between cooling and heating operation, comprising a second refrigerant circuit configured to switch between cooling and heating operation and in which refrigerant circulates, and comprising a second heat transfer medium heat exchanger configured to perform heat exchange with the second refrigerant circuit, a first load device comprising a first load-side heat exchanger, a second load device comprising a second load-side heat exchanger, a first heat transfer circuit in which the first heat transfer fluid heat exchanger and the first load-side heat exchanger are connected by a drain heat transfer fluid line and a return heat transfer fluid line, and in which a heat transfer fluid circulates, and a second heat transfer circuit in which the second heat transfer fluid heat exchanger and the second load-side heat exchanger are connected by a heat transfer fluid line and in which a heat transfer fluid circulates. [2] Heat pump device comprising: a heat source unit comprising a first refrigerant circuit designed to switch between cooling and heating operation and in which refrigerant circulates, and comprising a first heat transfer medium heat exchanger designed to perform heat exchange with the first refrigerant circuit, a first load device comprising a first load-side heat exchanger, a first heat transfer circuit in which the first heat transfer fluid heat exchanger and the first load-side heat exchanger are connected by a drain heat transfer fluid line and a return heat transfer fluid line, and in which a heat transfer fluid circulates, and a second load device comprising a second refrigerant circuit, designed to switch between cooling and heating operation, in which refrigerant circulates, a second heat transfer fluid heat exchanger, which is designed to perform a heat exchange with the second refrigerant circuit, and a second heat transfer circuit in which the second heat transfer fluid heat exchanger and the second load-side heat exchanger are connected by a heat transfer fluid line and in which a heat transfer fluid circulates. [3] Heat pump device according to claim 1 or 2, wherein the first heat transfer fluid heat exchanger and the second heat transfer fluid heat exchanger are each designed to to serve as an evaporator in cooling operation and in heating mode they serve as a capacitor, and and are set up to ensure that the first heat transfer fluid heat exchanger serves as an evaporator and the second heat transfer fluid heat exchanger as a condenser, or the first heat transfer fluid heat exchanger serves as a condenser and the second heat transfer fluid heat exchanger as an evaporator.

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