Refrigeration cycle device

Abstract

This refrigeration cycle device is provided with a heat source machine, a relay machine, and a plurality of load devices. The heat source machine includes a first refrigerant circuit and a first heat medium heat exchanger. The relay machine includes a second refrigerant circuit, a second heat medium heat exchanger, and a third heat medium heat exchanger. In the refrigeration cycle device, the first heat medium heat exchanger and the plurality of load devices are connected by first heat medium piping to form a first heat medium circuit through which a heat medium circulates. The heat source machine further includes a fourth heat medium heat exchanger. In the refrigeration cycle device, the fourth heat medium heat exchanger, the second heat medium heat exchanger, the plurality of load devices, and the third heat medium heat exchanger are connected in the stated order by second heat medium piping, and a second heat medium circuit that merges with the first heat medium piping between the downstream side of the plurality of load devices and the upstream side of the first heat medium heat exchanger, and a third heat medium circuit that branches from the upstream side of the first heat medium heat exchanger in the first heat medium circuit and that is connected to the fourth heat medium heat exchanger, are formed on the downstream side of the third heat medium heat exchanger.

Description

Refrigeration Cycle Equipment

[0001] The present disclosure relates to a refrigeration cycle device capable of simultaneous cooling and heating operations.

[0002] An example of a refrigeration cycle device capable of simultaneous cooling and heating operation is the air conditioner disclosed in Patent Document 1. The air conditioner of Patent Document 1 has one outdoor unit as a heat source unit, multiple indoor units as load units, and a relay unit interposed between the outdoor unit and the multiple indoor units, and the outdoor unit and the relay unit, and the relay unit and the indoor units are each connected by two pipes through which water, which serves as a heat medium, flows. In the air conditioner of Patent Document 1, the indoor unit that performs cooling is connected to a heat medium circuit through which cold water circulates, and the indoor unit that performs heating is connected to a heat medium circuit through which hot water circulates, allowing each indoor unit to freely select between cooling and heating.

[0003] International Publication No. 2014 / 097870

[0004] The air conditioner of Patent Document 1 has a configuration in which a heat medium circuit connected to an indoor unit that performs cooling and through which cold water circulates is independent from a heat medium circuit connected to an indoor unit that performs heating and through which hot water circulates. The air conditioner of Patent Document 1 has independent heat medium circuits through which cold water circulates and hot water circulates, and does not consider heat transfer between the two circuits, resulting in ineffective use of the heat recovered from the heat medium that has passed through the indoor unit. For this reason, the air conditioner of Patent Document 1 has issues in terms of reducing power consumption.

[0005] The present disclosure is made to solve the above-mentioned problems, and has an object to provide a refrigeration cycle device that can reduce power consumption.

[0006] A refrigeration cycle apparatus according to the present disclosure is a refrigeration cycle apparatus including a heat source unit, a relay unit connected to the heat source unit, and a plurality of load devices connected to the relay unit, wherein the heat source unit includes a first refrigerant circuit through which a refrigerant circulates, the first refrigerant circuit having a first heat medium heat exchanger that exchanges heat between the refrigerant flowing in the first refrigerant circuit and a heat medium flowing therein, the relay unit includes a second refrigerant circuit through which the refrigerant circulates, the second refrigerant circuit having a second heat medium heat exchanger that exchanges heat between the refrigerant flowing in the second refrigerant circuit and the heat medium flowing therein, and a third heat medium heat exchanger that exchanges heat between the refrigerant flowing in the second refrigerant circuit and the heat medium flowing therein, and the first heat medium heat exchanger and the plurality of load devices are connected to a first heat medium piping. a first heat medium circuit through which a heat medium circulates, and the heat source machine further has a fourth heat medium heat exchanger that exchanges heat between the refrigerant flowing in the first refrigerant circuit and the heat medium flowing therein, and the fourth heat medium heat exchanger, the second heat medium heat exchanger, the plurality of load devices, and the third heat medium heat exchanger are connected in this order by second heat medium piping, forming a second heat medium circuit in which the downstream side of the third heat medium heat exchanger joins with the first heat medium piping between the downstream side of the plurality of load devices and the upstream side of the first heat medium heat exchanger, and a third heat medium circuit that branches off from the first heat medium circuit upstream of the first heat medium heat exchanger and has third heat medium piping connected to the fourth heat medium heat exchanger.

[0007] A refrigeration cycle device according to the present disclosure includes a first heat medium circuit, a second heat medium circuit, and a third heat medium circuit, which are interconnected to perform heat accommodation. The refrigeration cycle device performs heat accommodation, thereby reducing power consumption.

[0008] 1 is a refrigerant circuit diagram of a refrigeration cycle device according to Embodiment 1. FIG. 1 is a refrigerant circuit diagram showing the flow of a heat medium in cooling operation of the refrigeration cycle device according to Embodiment 1. FIG. 2 is a refrigerant circuit diagram showing the flow of a heat medium in heating operation of the refrigeration cycle device according to Embodiment 1. FIG. 3 is a refrigerant circuit diagram showing the flow of a heat medium in cooling-dominated operation of the refrigeration cycle device according to Embodiment 1. FIG. 4 is a refrigerant circuit diagram showing the flow of a heat medium in heating-dominated operation of the refrigeration cycle device according to Embodiment 1. FIG. 5 is a refrigerant circuit diagram showing the flow of a heat medium in cooling-dominated operation of the refrigeration cycle device according to Embodiment 1. FIG. 6 is a refrigerant circuit diagram showing the flow of a refrigerant and a heat medium in cooling-dominated operation of a comparative example. FIG. 7 is a refrigerant circuit diagram showing the flow of a refrigerant and a heat medium in heating-dominated operation of a comparative example. FIG. 8 is a diagram showing temperature changes of the refrigerant and the heat medium in an evaporator of a second refrigerant circuit in cooling-dominated operation of the refrigeration cycle device according to Embodiment 1. FIG. 9 is a diagram showing temperature changes of the refrigerant and the heat medium in an evaporator of the second refrigerant circuit in cooling-dominated operation of a comparative example. FIG. 10 is a diagram showing temperature changes of the refrigerant and the heat medium in a condenser of the second refrigerant circuit in cooling-dominated operation of the refrigeration cycle device according to Embodiment 1. FIG. 11 is a diagram showing temperature changes of the refrigerant and the heat medium in a condenser of the second refrigerant circuit in cooling-dominated operation of a comparative example. 1 is a refrigerant circuit diagram showing a flow of a heat medium in a cooling-dominated operation in a modified example of the refrigeration cycle apparatus 100 according to Embodiment 1. FIG. 2 is a refrigerant circuit diagram showing a flow of a heat medium in a heating-dominated operation in a modified example of the refrigeration cycle apparatus 100 according to Embodiment 1.

[0009] Hereinafter, in each embodiment, an example of a refrigeration cycle device according to the present disclosure will be described with reference to the drawings. Herein, in the following drawings including FIG. 1, the same reference numerals are used to denote the same or equivalent parts. This rule will be applied to all of the embodiments described below. The refrigeration cycle device according to the present disclosure is not limited to the form described in the specification.

[0010] Embodiment 1. Fig. 1 is a refrigerant circuit diagram of a refrigeration cycle apparatus 100 according to Embodiment 1. As shown in Fig. 1, the refrigeration cycle apparatus according to Embodiment 1 includes a heat source unit 1, a relay unit 2 connected to the heat source unit 1, and a plurality of load devices 3 connected to the relay unit 2. Hereinafter, an example is shown in which four load devices 3A, 3B, 3C, and 3D are connected, but the number of load devices 3 may be two or more. Hereinafter, when there is no need to distinguish between the load devices 3A, 3B, 3C, and 3D, they will be collectively referred to as the load devices 3.

[0011] The heat source unit 1 is, for example, an outdoor unit. The load device 3 is, for example, an indoor unit that supplies temperature-controlled air indoors. The heat source unit 1 is installed, for example, on the roof of a building. The relay unit 2 and the load device 3 are installed, for example, inside the building. The components that make up the heat source unit 1, the relay unit 2, and the load device 3 are controlled by a control device 101.

[0012] As shown in Fig. 1, the heat source unit 1 includes a first refrigerant circuit 10 through which a refrigerant circulates. The first refrigerant circuit 10 includes a first heat medium heat exchanger 11 that exchanges heat between the refrigerant flowing through the first refrigerant circuit 10 and a heat medium flowing therein, and a fourth heat medium heat exchanger 17 that exchanges heat between the refrigerant flowing through the first refrigerant circuit 10 and the heat medium flowing therein. The relay unit 2 includes a second refrigerant circuit 20 through which a refrigerant circulates. The second refrigerant circuit 20 includes a second heat medium heat exchanger 21 that exchanges heat between the refrigerant flowing through the second refrigerant circuit 20 and the heat medium flowing therein, and a third heat medium heat exchanger 22 that exchanges heat between the refrigerant flowing through the second refrigerant circuit 20 and the heat medium flowing therein. The load device 3 includes a load-side heat exchanger 30.

[0013] The first refrigerant circuit 10 contains, for example, R290, NH ３The second refrigerant circuit 20 is filled with a non-flammable or slightly flammable refrigerant such as R410A, R32, olefin, or a mixture of these refrigerants. This is because the heat source unit 1 is mainly installed outdoors, and so a flammable refrigerant with a small global warming effect is used. The second refrigerant circuit 20 is filled with a non-flammable or slightly flammable refrigerant such as R410A, R32, olefin, or a mixture of these refrigerants. This is because the relay unit 2 is mainly installed indoors. The refrigerant filled in the first refrigerant circuit 10 and the second refrigerant circuit 20 is not limited to the above-mentioned refrigerants, and may be refrigerants commonly used in air conditioning at present, such as R410A or R32, R290, CO ２ , N.H. ３ For example, the refrigerant filled in the second refrigerant circuit 20 may be, in consideration of safety, R290, NH ３ Alternatively, a flammable refrigerant such as olefin may be enclosed.

[0014] The amount of refrigerant circulating through the first refrigerant circuit 10 is greater than the amount of refrigerant circulating through the second refrigerant circuit 20. The amount of refrigerant charged in the first refrigerant circuit 10 is, for example, 5 kg or less. The amount of refrigerant charged in the second refrigerant circuit 20 is, for example, less than 1 kg, which is the standard for using a flammable refrigerant indoors. The first refrigerant circuit 10 is mainly used for load devices 3 with heavy operating loads. In other words, in order to improve operating efficiency, the refrigeration cycle apparatus 100 has a greater amount of refrigerant circulating through the first refrigerant circuit 10 than the amount of refrigerant circulating through the second refrigerant circuit 20.

[0015] In the refrigeration cycle apparatus 100, the first heat medium heat exchanger 11 and the load side heat exchanger 30 are connected by a first heat medium piping 40 to form a first heat medium circuit 4 through which a heat medium circulates. The refrigeration cycle apparatus 100 also has a second heat medium circuit 5. The second heat medium circuit 5 is a circuit in which the fourth heat medium heat exchanger 17, the second heat medium heat exchanger 21, the load side heat exchanger 30, and the third heat medium heat exchanger 22 are connected in this order by the second heat medium piping 50, and the downstream side of the third heat medium heat exchanger 22 merges at a junction A with the first heat medium piping 40 between the downstream side of the load side heat exchanger 30 and the upstream side of the first heat medium heat exchanger 11. The refrigeration cycle apparatus 100 also includes a third heat medium circuit 8 having a third heat medium pipe 80 that branches off from a branch point B upstream of the first heat medium heat exchanger 11 in the first heat medium circuit 4 and is connected to a fourth heat medium heat exchanger 17. The third heat medium circuit 8 is configured by the third heat medium pipe 80.

[0016] In the refrigeration cycle apparatus 100, the heat source unit 1 and the relay unit 2 are connected by two pipes of a first heat medium circuit 4. In addition, in the refrigeration cycle apparatus 100, the heat source unit 1 and the relay unit 2 are connected by one pipe of a second heat medium circuit 5. In other words, in the refrigeration cycle apparatus 100, the heat source unit 1 and the relay unit 2 are connected by three pipes.

[0017] Here, the outlet of the second heat medium pipe 50 is connected to the first heat medium pipe 40 at a junction A between the load device 3 and the first heat medium heat exchanger 11 in the first heat medium circuit 4. The inlet of the third heat medium pipe 80 is connected to the first heat medium pipe 40 at a branch point B upstream of the first heat medium heat exchanger 11 in the first heat medium circuit 4. The junction point A is located inside the relay unit 2, and the branch point B is located inside the heat source unit 1. If the junction point A were located inside the heat source unit 1 or the branch point B were located inside the relay unit 2, the number of pipes between the heat source unit 1 and the relay unit 2 would increase. However, in the refrigeration cycle apparatus 100, the junction point A is located inside the relay unit 2 and the branch point B is located inside the heat source unit 1, so the number of pipes between the heat source unit 1 and the relay unit 2 is three.

[0018] The first heat medium circuit 4 and the second heat medium circuit 5 are provided with a first flow switching device 6a that switches the flow path of the heat medium flowing into the load device 3 to either the first heat medium circuit 4 or the second heat medium circuit 5. The first heat medium circuit 4 and the second heat medium circuit 5 are also provided with a second flow switching device 6b that switches the flow path of the heat medium flowing out of the load device 3 to either the first heat medium circuit 4 or the second heat medium circuit 5. The second heat medium circuit 5 is provided with a flow switching device 9 that guides the refrigerant flowing out of the fourth heat medium heat exchanger 17 to the second heat medium heat exchanger 21. The heat medium is, for example, water, brine, or a mixture of brine and water.

[0019] First, a configuration of the heat source unit 1 will be described. The heat source unit 1 includes a first refrigerant circuit 10 through which a refrigerant circulates. The first refrigerant circuit 10 includes a first compressor 12, a first flow switching valve 13, a heat source side heat exchanger 14, a first expansion mechanism 15, a first heat medium heat exchanger 11, a third expansion mechanism 18, and a fourth heat medium heat exchanger 17. In the first refrigerant circuit 10, the first compressor 12, the first flow switching valve 13, the heat source side heat exchanger 14, the first expansion mechanism 15, and the first heat medium heat exchanger 11 are connected in sequence by refrigerant piping.

[0020] In the first refrigerant circuit 10, the third expansion mechanism 18 and the fourth heat medium heat exchanger 17 are connected in parallel to the first expansion mechanism 15 and the heat source side heat exchanger 14. More specifically, a circuit in which the third expansion mechanism 18 and the fourth heat medium heat exchanger 17 are connected in series by refrigerant piping is connected in parallel to a circuit in which the first expansion mechanism 15 and the heat source side heat exchanger 14 are connected in series by refrigerant piping. The first refrigerant circuit 10 may include other components in addition to the above-mentioned components, or may omit some components.

[0021] The first compressor 12 is, for example, an inverter compressor. When the first compressor 12 is an inverter compressor, the operating frequency may be changed arbitrarily by an inverter circuit or the like to change the refrigerant discharge capacity per unit time. In this case, the operation of the inverter circuit is controlled by the control device 101. The refrigerant discharged from the first compressor 12 flows into the heat source side heat exchanger 14 and the fourth heat medium heat exchanger 17, or the first heat medium heat exchanger 11, via the first flow path switching valve 13.

[0022] The first flow path switching valve 13 is, for example, a four-way valve and has a function of switching the refrigerant flow path. During cooling operation, the first flow path switching valve 13 connects the refrigerant discharge side of the first compressor 12 to the heat source side heat exchanger 14 and the fourth heat medium heat exchanger 17, and switches the refrigerant flow path to connect the refrigerant suction side of the first compressor 12 to the first heat medium heat exchanger 11. Meanwhile, during heating operation, the first flow path switching valve 13 connects the refrigerant discharge side of the first compressor 12 to the first heat medium heat exchanger 11, and switches the refrigerant flow path to connect the refrigerant suction side of the first compressor 12 to the heat source side heat exchanger 14 and the fourth heat medium heat exchanger 17. The first flow path switching valve 13 may be configured as a combination of two-way valves or three-way valves.

[0023] The heat source-side heat exchanger 14 functions as a condenser during cooling operation. The heat source-side heat exchanger 14 also functions as an evaporator during heating operation. The heat source-side heat exchanger 14 draws in outdoor air using the heat source-side blower 16, exchanges heat with the refrigerant flowing inside, and discharges the air to the outside.

[0024] The first expansion mechanism 15 reduces the pressure of the refrigerant flowing through the first refrigerant circuit 10 to expand it, and is configured, for example, by an electronic expansion valve whose opening degree is variably controlled.

[0025] The first heat medium heat exchanger 11 exchanges heat between the heat medium and the refrigerant. The first heat medium heat exchanger 11 is a flow path of the first refrigerant circuit 10 and a flow path of the first heat medium circuit 4. That is, the first heat medium heat exchanger 11 is a component of the first refrigerant circuit 10 and a component of the first heat medium circuit 4. The first heat medium heat exchanger 11 functions as an evaporator during cooling operation and exchanges heat between the refrigerant flowing out of the first expansion mechanism 15 and the third expansion mechanism 18 and the heat medium, evaporating the refrigerant and cooling the heat medium. The first heat medium heat exchanger 11 functions as a condenser during heating operation and exchanges heat between the refrigerant flowing in from the first compressor 12 and the heat medium, condensing the refrigerant to liquefy or convert it into a gas-liquid two-phase state, and heating the heat medium.

[0026] The third expansion mechanism 18 reduces the pressure of the refrigerant flowing through the first refrigerant circuit 10 to expand it, and is configured, for example, by an electronic expansion valve whose opening degree is variably controlled.

[0027] The fourth heat medium heat exchanger 17 exchanges heat between the heat medium and the refrigerant. The fourth heat medium heat exchanger 17 serves as a flow path for the first refrigerant circuit 10, the second heat medium circuit 5, and the third heat medium circuit 8. In other words, the fourth heat medium heat exchanger 17 serves as a component of the first refrigerant circuit 10, the second heat medium circuit 5, and the third heat medium circuit 8. The refrigerant and the heat medium pass through the fourth heat medium heat exchanger 17 in the cooling-dominated operation and the heating-dominated operation described below, but neither the refrigerant nor the heat medium passes through the fourth heat medium heat exchanger 17 in the cooling-only operation and the heating-only operation.

[0028] The fourth heat medium heat exchanger 17 functions as a condenser during cooling-dominated operation, exchanging heat between the refrigerant flowing in from the first compressor 12 and the heat medium, condensing the refrigerant to liquefy or convert it into a gas-liquid two-phase state, and heating the heat medium. The fourth heat medium heat exchanger 17 functions as an evaporator during heating-dominated operation, exchanging heat between the refrigerant flowing out from the third expansion mechanism 18 and the heat medium, evaporating the refrigerant to vaporize it, and cooling the heat medium.

[0029] The relay unit 2 includes a second refrigerant circuit 20 through which a refrigerant circulates. The second refrigerant circuit 20 includes a second heat medium heat exchanger 21, a third heat medium heat exchanger 22, and first flow switching devices 6a and 6b. The second refrigerant circuit 20 includes a second compressor 23, a second flow switching valve 24, the second heat medium heat exchanger 21, a second expansion mechanism 25, and the third heat medium heat exchanger 22, which are sequentially connected by refrigerant piping. The second refrigerant circuit 20 may include other components in addition to the above-described components, or may omit some components.

[0030] The second compressor 23 is, for example, an inverter compressor, and has basically the same configuration as the first compressor 12. The refrigerant discharged from the second compressor 23 flows into the second heat medium heat exchanger 21 or the third heat medium heat exchanger 22 via a second flow path switching valve 24.

[0031] The second flow path switching valve 24 is, for example, a four-way valve and has basically the same configuration as the first flow path switching valve 13. The second flow path switching valve 24 switches the flow direction of the refrigerant discharged from the second compressor 23 to the second heat medium heat exchanger 21 or the third heat medium heat exchanger 22. During cooling operation, the second flow path switching valve 24 connects the refrigerant discharge side of the second compressor 23 to the second heat medium heat exchanger 21 and switches the refrigerant flow path to connect the refrigerant suction side of the second compressor 23 to the third heat medium heat exchanger 22. On the other hand, during heating operation, the second flow path switching valve 24 connects the refrigerant discharge side of the second compressor 23 to the third heat medium heat exchanger 22 and switches the refrigerant flow path to connect the refrigerant suction side of the second compressor 23 to the second heat medium heat exchanger 21. The second flow path switching valve 24 may be configured as a combination of two-way valves or three-way valves.

[0032] The second expansion mechanism 25 reduces the pressure of the refrigerant circulating in the second refrigerant circuit 20 to expand it, and is configured, for example, by an electronic expansion valve whose opening degree is variably controlled.

[0033] The second heat medium heat exchanger 21 exchanges heat between the heat medium and the refrigerant. The second heat medium heat exchanger 21 serves as a flow path for the second refrigerant circuit 20 and the second heat medium circuit 5. That is, the second heat medium heat exchanger 21 serves as a component of the second refrigerant circuit 20 and a component of the second heat medium circuit 5. In particular, when the second heat medium heat exchanger 21 functions as a condenser, it is preferable to configure the piping so that the refrigerant circulating through the second refrigerant circuit 20 and the heat medium passing through the second heat medium circuit 5 flow in counterflow directions to increase the heat exchange rate in the second heat medium heat exchanger 21.

[0034] When functioning as a condenser, the second heat medium heat exchanger 21 exchanges heat between the refrigerant flowing in from the second compressor 23 and the heat medium flowing out from the fourth heat medium heat exchanger 17, condensing the refrigerant to liquefy or convert the refrigerant into a gas-liquid two-phase state and heating the heat medium. When functioning as an evaporator, the second heat medium heat exchanger 21 exchanges heat between the refrigerant flowing out from the second expansion mechanism 25 and the heat medium flowing out from the fourth heat medium heat exchanger 17, evaporating the refrigerant to vaporize it and cooling the heat medium.

[0035] The third heat medium heat exchanger 22 exchanges heat between the heat medium and the refrigerant. The third heat medium heat exchanger 22 serves as a flow path for the second refrigerant circuit 20 and the second heat medium circuit 5. That is, the third heat medium heat exchanger 22 serves as a component of the second refrigerant circuit 20 and a component of the second heat medium circuit 5. In particular, when the third heat medium heat exchanger 22 functions as a condenser, it is preferable to configure the piping so that the refrigerant circulating through the second refrigerant circuit 20 and the heat medium passing through the second heat medium circuit 5 flow in counterflow directions to increase the heat exchange rate in the third heat medium heat exchanger 22.

[0036] When functioning as an evaporator, the third heat medium heat exchanger 22 exchanges heat between the refrigerant flowing out from the second expansion mechanism 25 and the heat medium flowing out from the load side heat exchanger 30, evaporating the refrigerant and cooling the heat medium. When functioning as a condenser, the third heat medium heat exchanger 22 exchanges heat between the refrigerant flowing in from the second compressor 23 and the heat medium flowing out from the load side heat exchanger 30, condensing the refrigerant to liquefy or convert it into a gas-liquid two-phase state, and heating the heat medium.

[0037] The first flow switching device 6a is provided in common to the first heat medium circuit 4 and the second heat medium circuit 5, and is provided on the heat medium inlet side of the load-side heat exchanger 30. The first flow switching device 6a switches the flow path of the heat medium. The first flow switching device 6a switches the destination of the heat medium flowing into the load-side heat exchanger 30 to either the first heat medium circuit 4 or the second heat medium circuit 5.

[0038] Here, the first flow path switching device 6a is configured as a three-way valve. The three-way valve constituting the first flow path switching device 6a has three ports connected to the first heat medium heat exchanger 11, the second heat medium heat exchanger 21, and the load-side heat exchanger 30. The three-way valve constituting the first flow path switching device 6a is switched between a first state in which the port connected to the first heat medium heat exchanger 11 communicates with the port connected to the load-side heat exchanger 30, and a second state in which the port connected to the second heat medium heat exchanger 21 communicates with the port connected to the load-side heat exchanger 30. When the first flow path switching device 6a is in the first state, the heat medium flows into the first heat medium heat exchanger 11. When the first flow path switching device 6a is in the second state, the heat medium flows into the load-side heat exchanger 30.

[0039] The first flow path switching device 6a is controlled by the control device 101. The first flow path switching device 6a is not limited to a three-way valve, and may be configured, for example, by combining two two-way valves whose valve opening degrees (opening areas) can be controlled.

[0040] The second flow path switching device 6b is provided in common to the first heat medium circuit 4 and the second heat medium circuit 5, and is provided on the heat medium outlet side of the load-side heat exchanger 30. The second flow path switching device 6b switches the flow path of the heat medium. The second flow path switching device 6b switches the destination of the heat medium flowing out of the load-side heat exchanger 30 to either the first heat medium circuit 4 or the second heat medium circuit 5.

[0041] The second flow path switching device 6b is configured as a three-way valve. The three-way valve constituting the second flow path switching device 6b has three ports connected to the third heat medium heat exchanger 22, a junction C (described later), and the load-side heat exchanger 30. The three-way valve constituting the second flow path switching device 6b is switched between a first state in which the port connected to the junction C communicates with the port connected to the load-side heat exchanger 30, and a second state in which the port connected to the third heat medium heat exchanger 22 communicates with the port connected to the load-side heat exchanger 30. When the second flow path switching device 6b is in the first state, the heat medium from the load-side heat exchanger 30 flows to the junction C. When the second flow path switching device 6b is in the second state, the heat medium from the load-side heat exchanger 30 flows to the third heat medium heat exchanger 22. The junction C is a portion on the first heat medium pipe 40 where the heat medium flowing out from each load device 3 in the first heat medium circuit 4 joins.

[0042] The second flow path switching device 6b is controlled to switch by the control device 101. The second flow path switching device 6b is not limited to a three-way valve, and may be configured, for example, by combining two two-way valves whose valve opening degrees (opening areas) can be controlled.

[0043] The flow path switching device 9 is configured as a three-way valve and is provided upstream of the second heat medium heat exchanger 21 in the second heat medium pipe 50 inside the relay unit 2. The flow path switching device 9 is switched so as to always guide the refrigerant flowing out of the fourth heat medium heat exchanger 17 to the second heat medium heat exchanger 21.

[0044] The first heat medium circuit 4 is provided with a pump 41 that circulates the heat medium. The pump 41 is one of the devices that make up the first heat medium circuit 4, and is provided in the heat source unit 1, for example. The pump 41 draws water in the first heat medium circuit 4, applies pressure to it, and sends it out to circulate. The capacity of the pump 41 is changed by a pump inverter drive device (not shown). The pump inverter drive device changes the capacity of the pump 41 by arbitrarily changing the drive frequency based on instructions from the control device 101.

[0045] The pump 41 may be provided in the heat source unit 1 or in the relay unit 2. Furthermore, the pump 41 may be provided in both the heat source unit 1 and the relay unit 2. The refrigeration cycle device 100 shown in Fig. 1 is configured such that one pump 41 is connected in consideration of the pressure loss of the heat medium flowing between the heat source unit 1 and the load device 3. The pump 41 may also be provided in some or all of the multiple load devices 3.

[0046] The load device 3 includes a load-side heat exchanger 30 and a load-side blower 31. The load device 3 passes air from the indoor space through the load-side heat exchanger 30, generating an air flow that returns the air to the indoor space. The load-side heat exchanger 30 is, for example, a fin-tube heat exchanger that exchanges heat between the indoor air in the indoor space supplied from the load-side blower 31 and a heat medium. During cooling operation, a heat medium that is colder than the indoor air passes through the heat transfer tubes of the load-side heat exchanger 30 to cool the indoor space. On the other hand, during heating operation, a heat medium that is warmer than the indoor air passes through the heat transfer tubes of the load-side heat exchanger 30 to heat the indoor space. Although not shown, the load device 3 may include a flow rate control device that adjusts the flow rate of the heat medium flowing into the load-side heat exchanger 30.

[0047] The control device 101 controls the operation of the entire refrigeration cycle device. Specifically, the control device 101 controls the drive frequency of the compressor, the rotation speed of the blower, switching of the flow path switching device, the opening degree of the expansion mechanism, the drive frequency of the pump, etc. The control device 101 is composed of a computer including a memory for storing data and programs required for control and a CPU for executing programs, dedicated hardware such as an ASIC or FPGA, or both.

[0048] 1 illustrates the refrigeration cycle apparatus 100 in a configuration in which the relay unit 2 is equipped with the first flow path switching devices 6a and 6b, but the first flow path switching devices 6a and 6b may be configured separately from the relay unit 2. In other words, the refrigeration cycle apparatus 100 may be configured such that the distribution device having the first flow path switching devices 6a and 6b and the relay unit 2 having the second compressor 23, the second flow path switching valve 24, the second heat medium heat exchanger 21, the second expansion mechanism 25, and the third heat medium heat exchanger 22 are independent and housed in separate housings.

[0049] Next, a description will be given of various operation modes performed by the refrigeration cycle apparatus 100. The operation modes of the refrigeration cycle apparatus include four modes: cooling only operation, heating only operation, cooling-dominated operation, and heating-dominated operation.

[0050] Cooling operation is an operation mode in which only cooling is possible in the load device 3, and the load device 3 is either cooling or stopped. Heating operation is an operation mode in which only heating is possible in the load device 3, and the load device 3 is either heating or stopped. Cooling-dominated operation is an operation mode in which cooling or heating can be selected for each load device 3, and in simultaneous cooling and heating operation in which a load device 3 performing cooling and a load device 3 performing heating exist simultaneously, the cooling load is larger than the heating load. Heating-dominated operation is an operation mode in which cooling or heating can be selected for each load device 3, and in simultaneous cooling and heating operation in which a load device 3 performing cooling and a load device 3 performing heating exist simultaneously, the heating load is larger than the cooling load.

[0051] In the following, it is assumed that the load on each load device 3 is the same, and that an operation with a larger number of load devices 3 has a larger load than an operation with a smaller number of load devices 3. In other words, if three of the four load devices are performing cooling and one is performing heating, the cooling load is assumed to be larger than the heating load.

[0052] Before describing each operation, we will explain how to read the figures common to FIGS. 2 to 5, which will be described later. In FIGS. 2 to 5, the black and white triangles of the symbols 6a and 6b indicate the switching states of the first flow path switching device 6a and the second flow path switching device 6b. In the symbols 6a and 6b, when the upper triangle of the three triangles on the left, right, and bottom is black, it means that the first flow path switching device 6a and the second flow path switching device 6b are switched to the first state. In the symbols 6a and 6b, when the left triangle of the three triangles on the left, right, and bottom is black, it means that the first flow path switching device 6a and the second flow path switching device 6b are switched to the second state.

[0053] (Cooling operation) Fig. 2 is a refrigerant circuit diagram showing the flow of the heat medium during cooling operation of the refrigeration cycle apparatus 100 according to Embodiment 1. Fig. 2 shows the flow of the heat medium when cooling is performed by all of the load devices 3. In the refrigeration cycle apparatus 100 according to Embodiment 1, when cooling is performed by all of the load devices 3, the first flow switching device 6a and the second flow switching device 6b are set to the first state, the second refrigerant circuit 20 is stopped, and only the first refrigerant circuit 10 and the first heat medium circuit 4 are operated. Furthermore, the refrigeration cycle apparatus 100 fully closes the third expansion mechanism 18, so that neither the refrigerant nor the heat medium passes through the fourth heat medium heat exchanger 17.

[0054] In the first refrigerant circuit 10, high-temperature, high-pressure gas refrigerant discharged from the first compressor 12 passes through the first flow switching valve 13 and flows to the heat source side heat exchanger 14, where it exchanges heat with air and is condensed and liquefied. The condensed and liquefied refrigerant is decompressed in the first expansion mechanism 15 to become a low-pressure gas-liquid two-phase refrigerant, and flows to the first heat medium heat exchanger 11, where it exchanges heat with the heat medium flowing in the first heat medium circuit 4 and is evaporated and gasified. The gasified refrigerant passes through the first flow switching valve 13 and is drawn into the first compressor 12 via an accumulator.

[0055] On the other hand, the heat medium flowing through the first heat medium circuit 4 is cooled by the refrigerant flowing through the first heat medium heat exchanger 11 to become cold water, and then flows through the relay unit 2 to the load side heat exchanger 30, where it is heated by heat exchange with the indoor air in the indoor space. The heated heat medium passes through the relay unit 2 and flows into the first heat medium heat exchanger 11 again.

[0056] (Heating operation) Fig. 3 is a refrigerant circuit diagram showing the flow of the heat medium during heating operation of the refrigeration cycle apparatus 100 according to Embodiment 1. Fig. 3 shows the flow of the heat medium when heating is performed by all of the load devices 3. In the refrigeration cycle apparatus 100 according to Embodiment 1, when heating is performed by all of the load devices 3, the first flow switching device 6a and the second flow switching device 6b are set to the first state, the second refrigerant circuit 20 is stopped, and the first refrigerant circuit 10 and the first heat medium circuit 4 are operated. Furthermore, the refrigeration cycle apparatus 100 fully closes the third expansion mechanism 18, so that neither the refrigerant nor the heat medium passes through the fourth heat medium heat exchanger 17.

[0057] In the first refrigerant circuit 10, high-temperature, high-pressure gas refrigerant discharged from the first compressor 12 passes through the first flow switching valve 13 and flows to the first heat medium heat exchanger 11. The refrigerant flowing into the first heat medium heat exchanger 11 exchanges heat with the heat medium flowing through the first heat medium circuit 4, condenses, and liquefies, and is reduced in pressure by the first expansion mechanism 15 to become a low-pressure gas-liquid two-phase refrigerant, which flows to the heat source-side heat exchanger 14. The gas-liquid two-phase refrigerant flowing into the heat source-side heat exchanger 14 exchanges heat with air and evaporates, passes through the first flow switching valve 13, and is drawn into the first compressor 12 via an accumulator.

[0058] On the other hand, the heat medium flowing through the first heat medium circuit 4 is heated by the refrigerant flowing through the first heat medium heat exchanger 11 to become hot water, and then flows through the relay unit 2 to the load side heat exchanger 30, where it is cooled by heat exchange with the indoor air in the indoor space. The cooled heat medium passes through the relay unit 2 and flows into the first heat medium heat exchanger 11 again.

[0059] (Cooling-dominated operation) Fig. 4 is a refrigerant circuit diagram showing the flow of the heat medium in cooling-dominated operation of the refrigeration cycle apparatus 100 according to embodiment 1. Fig. 4 shows an example in which the load devices 3A, 3B, and 3C perform cooling, and the load device 3D performs heating. Note that the temperatures [°C] and flow rates [L / min] shown in the figure are merely examples, and are not limited to the temperatures and flow rates shown. This also applies to the subsequent figures.

[0060] In the refrigeration cycle apparatus 100, when cooling is performed in some of the load devices 3A, 3B, and 3C and heating is performed in the remaining load device 3D, the first refrigerant circuit 10, the first heat medium circuit 4, the second refrigerant circuit 20, the second heat medium circuit 5, and the third heat medium circuit 8 are operated. The refrigeration cycle apparatus 100 switches the first flow switching device 6a and the second flow switching device 6b connected to the load-side heat exchangers 30 of the load devices 3A, 3B, and 3C that perform cooling to the first state. The refrigeration cycle apparatus 100 switches the first flow switching device 6a and the second flow switching device 6b connected to the load-side heat exchanger 30 of the load device 3D that performs heating to the second state.

[0061] In the first refrigerant circuit 10, high-temperature, high-pressure gas refrigerant discharged from the first compressor 12 passes through the first flow switching valve 13 and flows to the heat source side heat exchanger 14 and the fourth heat medium heat exchanger 17. The refrigerant that flows into the heat source side heat exchanger 14 exchanges heat with air and condenses and liquefies. The refrigerant that flows into the fourth heat medium heat exchanger 17 exchanges heat with the heat medium that flows in from the third heat medium circuit 8 and condenses and liquefies. The condensed and liquefied refrigerant is decompressed by the first expansion mechanism 15 and the third expansion mechanism 18 to become a low-pressure gas-liquid two-phase refrigerant, and flows to the first heat medium heat exchanger 11, where it exchanges heat with the heat medium flowing in the first heat medium circuit 4 and evaporates and gasifies. The gasified refrigerant passes through the first flow switching valve 13 and is drawn into the first compressor 12 via an accumulator.

[0062] Meanwhile, the heat medium flowing through the first heat medium circuit 4 is cooled by the refrigerant flowing through the first heat medium heat exchanger 11 to become chilled water, and then flows via the relay unit 2 to the load-side heat exchangers 30 of the load devices 3A, 3B, and 3C that perform cooling, where it is heated by heat exchange with the indoor air in the indoor space. The heated heat medium merges at the junction C, passes through the junction A, and flows out of the relay unit 2. The heat medium flowing out of the relay unit 2 branches at the branch point B, with one branch flowing back into the first heat medium heat exchanger 11 and the other flowing through the third heat medium pipe 80 into the fourth heat medium heat exchanger 17.

[0063] The heat medium that flows into the fourth heat medium heat exchanger 17 in the second heat medium circuit 5 is heated by the refrigerant flowing through the fourth heat medium heat exchanger 17 to become high-temperature water, which then flows out of the heat source unit 1 and into the relay unit 2. In the illustrated example, between the heat source unit 1 and the relay unit 2, a 7°C heat medium that flows out of the first heat medium heat exchanger 11 and heads toward the relay unit 2, a 12°C heat medium that flows out of the relay unit 2 and heads toward the heat source unit 1, and a 17°C heat medium that flows out of the fourth heat medium heat exchanger 17 and heads toward the relay unit 2 pass. The fourth heat medium heat exchanger 17 produces high-temperature water at 17°C, which is the highest of the temperatures of 7°C, 12°C, and 17°C.

[0064] The high-temperature water that has flowed into the relay unit 2 first flows into the second heat medium heat exchanger 21, where it is further heated by the refrigerant flowing through the second refrigerant circuit 20, and then flows into the load-side heat exchanger 30 of the load device 3D that performs heating, where it is cooled by heat exchange with the indoor air in the indoor space. The cooled heat medium then flows into the third heat medium heat exchanger 22, where it is cooled by the refrigerant flowing through the second refrigerant circuit 20, and flows to the junction A where it merges with the heat medium flowing through the first heat medium circuit 4. As described above, the heat medium after the junction branches at the branch point B, with one flow flowing into the first heat medium heat exchanger 11 and the other flowing through the third heat medium pipe 80 into the fourth heat medium heat exchanger 17.

[0065] (Heating-dominated operation) Fig. 5 is a refrigerant circuit diagram showing the flow of the heat medium in heating-dominated operation of the refrigeration cycle apparatus 100 according to Embodiment 1. Fig. 5 shows an example in which the load devices 3A, 3B, and 3C perform heating, and the load device 3D performs cooling.

[0066] In the refrigeration cycle apparatus 100, when some of the load devices 3A, 3B, and 3C perform heating and the remaining load device 3D performs cooling, the first refrigerant circuit 10, the first heat medium circuit 4, the second refrigerant circuit 20, the second heat medium circuit 5, and the third heat medium circuit 8 are operated. The refrigeration cycle apparatus 100 switches the first flow switching device 6a and the second flow switching device 6b connected to the load-side heat exchangers 30 of the load devices 3A, 3B, and 3C that perform heating to the first state. The refrigeration cycle apparatus 100 switches the first flow switching device 6a and the second flow switching device 6b connected to the load-side heat exchanger 30 of the load device 3D that performs cooling to the second state.

[0067] In the first refrigerant circuit 10, high-temperature, high-pressure gas refrigerant discharged from the first compressor 12 passes through the first flow switching valve 13 and flows into the first heat medium heat exchanger 11. The refrigerant flowing into the first heat medium heat exchanger 11 exchanges heat with the heat medium flowing through the first heat medium circuit 4, condenses, and liquefies. The refrigerant is then reduced in pressure by the first expansion mechanism 15 and the third expansion mechanism 18 to become a low-pressure gas-liquid two-phase refrigerant, and flows into the heat source side heat exchanger 14 and the fourth heat medium heat exchanger 17. The gas-liquid two-phase refrigerant flowing into the heat source side heat exchanger 14 exchanges heat with air and evaporates. The gas-liquid two-phase refrigerant flowing into the fourth heat medium heat exchanger 17 exchanges heat with the heat medium flowing in from the third heat medium circuit 8 and evaporates. The evaporated heat medium passes through the first flow switching valve 13, passes through an accumulator, and is drawn into the first compressor 12.

[0068] Meanwhile, the heat medium flowing through the first heat medium circuit 4 is heated by the refrigerant flowing through the first heat medium heat exchanger 11 to become hot water, and then flows via the relay unit 2 to the load-side heat exchangers 30 of the heating load devices 3A, 3B, and 3C, where it is cooled by heat exchange with the indoor air in the indoor space. The cooled heat medium merges at the junction C, passes through the junction A, and flows out of the relay unit 2. The heat medium flowing out of the relay unit 2 branches at the branch point B, with one branch flowing back into the first heat medium heat exchanger 11 and the other flowing through the third heat medium pipe 80 into the fourth heat medium heat exchanger 17.

[0069] The heat medium that flows into the fourth heat medium heat exchanger 17 in the second heat medium circuit 5 is cooled by the refrigerant flowing through the fourth heat medium heat exchanger 17 to become low-temperature water, which then flows out of the heat source unit 1 and into the relay unit 2. In the illustrated example, between the heat source unit 1 and the relay unit 2, a 45°C heat medium that flows out of the first heat medium heat exchanger 11 and heads toward the relay unit 2, a 40°C heat medium that flows out of the relay unit 2 and heads toward the heat source unit 1, and a 17°C heat medium that flows out of the fourth heat medium heat exchanger 17 and heads toward the relay unit 2 pass. The fourth heat medium heat exchanger 17 produces low-temperature water at 17°C, the lowest of 17°C, 40°C, and 45°C.

[0070] The low-temperature water that flows into the relay unit 2 first flows into the second heat medium heat exchanger 21, where it is further cooled by the refrigerant flowing through the second refrigerant circuit 20, and then flows into the load-side heat exchanger 30 of the load device 3D that performs cooling, where it is heated by heat exchange with the indoor air in the indoor space. The heated heat medium then flows into the third heat medium heat exchanger 22, where it is heated by the refrigerant flowing through the second refrigerant circuit 20, and flows to the junction A where it merges with the heat medium flowing through the first heat medium circuit 4. As described above, the heat medium after the junction branches at the branch point B, with one flow flowing into the first heat medium heat exchanger 11 and the other flowing through the third heat medium pipe 80 into the fourth heat medium heat exchanger 17.

[0071] The above-described configuration and the action of the fluid flow will be described in comparison with the configuration of a comparative example. The refrigeration cycle device 100 achieves reduced power consumption compared to the comparative example in cooling-dominated operation and heating-dominated operation.

[0072] 6 and 7 are refrigerant circuit diagrams showing the configuration of a comparative example. The refrigeration cycle apparatus 100a of the comparative example has a heat source unit 1a, a relay unit 2a, and multiple load devices 3Aa and 3Ba. The refrigeration cycle apparatus 100a of the comparative example has a heat medium circuit connected to a load device 3 that performs cooling and through which chilled water circulates, and a heat medium circuit connected to a load device 3 that performs heating and through which hot water circulates, independent of each other. Compared to the refrigeration cycle apparatus 100, the refrigeration cycle apparatus 100a of the comparative example has a fourth heat medium heat exchanger 17 omitted from the heat source unit 1.

[0073] 6 is a refrigerant circuit diagram showing the flow of the refrigerant and the heat medium in the cooling-dominated operation in the comparative example. Hereinafter, the cooling-dominated operation in which one load device 3Aa performs cooling and the other load device 3Ba performs heating and the cooling load is large will be described.

[0074] In the refrigeration cycle apparatus 100a, when one load device 3Aa performs cooling and the other load device 3Ba performs heating, the first refrigerant circuit 10a, the first heat medium circuit 4a, the second refrigerant circuit 20a, and the second heat medium circuit 5a are operated. To connect the load-side heat exchanger 30a of the cooling load device 3Aa to the first heat medium circuit 4a, the first flow switching device 4aa is opened and the first flow switching device 5aa is closed. To connect the load-side heat exchanger 30a of the heating load device 3Ba to the second heat medium circuit 5a, the first flow switching device 4aa is closed and the first flow switching device 5aa is opened. In the refrigeration cycle apparatus 100a of the comparative example, the first heat medium circuit 4a connected to the cooling load device 3Aa and the second heat medium circuit 5a connected to the heating load device 3Ba are independent.

[0075] In the first refrigerant circuit 10a, high-temperature, high-pressure gas refrigerant discharged from the first compressor 12a passes through the first flow switching valve 13a and flows to the heat source side heat exchanger 14a, where it exchanges heat with air and is condensed and liquefied. The condensed and liquefied refrigerant is decompressed by the first expansion mechanism 15a to become a low-pressure gas-liquid two-phase refrigerant, and flows to the first heat medium heat exchanger 11a, where it exchanges heat with the heat medium flowing in the first heat medium circuit 4a and is evaporated and gasified. The gasified refrigerant passes through the first flow switching valve 13a and is drawn into the first compressor 12a via an accumulator.

[0076] The heat medium flowing through the first heat medium circuit 4a is cooled by the refrigerant flowing through the first heat medium heat exchanger 11a to become cold water, and then flows through the relay unit 2a to the load-side heat exchanger 30a of the load device 3Aa, where it is heated by heat exchange with the indoor air in the indoor space. The heated heat medium then flows to the second heat medium heat exchanger 21a, where it is cooled by heat exchange with the refrigerant circulating through the second refrigerant circuit 20a, and then flows back into the first heat medium heat exchanger 11a.

[0077] In the second refrigerant circuit 20a, high-temperature, high-pressure gas refrigerant discharged from the second compressor 23a passes through the second flow switching valve 24a and flows to the third heat medium heat exchanger 22a, where it condenses and liquefies through heat exchange with the heat medium flowing in the second heat medium circuit 5a. The condensed and liquefied refrigerant is decompressed by the second expansion mechanism 25a to become a low-pressure gas-liquid two-phase refrigerant, and flows to the second heat medium heat exchanger 21a, where it exchanges heat with the heat medium flowing in the first heat medium circuit 4a to evaporate and gasify. The gasified refrigerant passes through the second flow switching valve 24a and is drawn into the second compressor 23a via an accumulator.

[0078] On the other hand, the heat medium flowing through the second heat medium circuit 5a is heated by the refrigerant flowing through the third heat medium heat exchanger 22a to become hot water, and then flows into the load-side heat exchanger 30a of the load device 3Ba, where it is cooled by heat exchange with the indoor air in the indoor space. The cooled heat medium then flows into the third heat medium heat exchanger 22a again.

[0079] 7 is a refrigerant circuit diagram showing the flow of the refrigerant and the heat medium in the heating-dominated operation in a comparative example. Hereinafter, the heating-dominated operation in which one load device 3Aa performs cooling and the other load device 3Ba performs heating and the heating load is large will be described.

[0080] In the refrigeration cycle apparatus 100a, when one load device 3Aa performs cooling and the other load device 3Ba performs heating, the first refrigerant circuit 10a, the first heat medium circuit 4a, the second refrigerant circuit 20a, and the second heat medium circuit 5a are operated. To connect the load-side heat exchanger 30a of the cooling load device 3Aa to the second heat medium circuit 5a, the first flow switching device 4aa is closed and the first flow switching device 5aa is opened. To connect the load-side heat exchanger 30a of the heating load device 3Ba to the first heat medium circuit 4a, the first flow switching device 4aa is opened and the first flow switching device 5aa is closed. In the refrigeration cycle apparatus 100a of the comparative example, the first heat medium circuit 4a connected to the cooling load device 3Aa and the second heat medium circuit 5a connected to the heating load device 3Ba are independent.

[0081] In the first refrigerant circuit 10a, high-temperature, high-pressure gas refrigerant discharged from the first compressor 12a passes through the first flow switching valve 13a and flows to the first heat medium heat exchanger 11a. The refrigerant flowing in the first heat medium heat exchanger 11a exchanges heat with the heat medium flowing in the first heat medium circuit 4a to condense and liquefy, is decompressed by the first expansion mechanism 15a to become low-pressure gas-liquid two-phase refrigerant, and flows to the heat source side heat exchanger 14a. The gas-liquid two-phase refrigerant flowing in the heat source side heat exchanger 14a exchanges heat with air to evaporate and gasify, passes through the first flow switching valve 13a, and is drawn into the first compressor 12a via an accumulator.

[0082] The heat medium flowing through the first heat medium circuit 4a is heated by the refrigerant flowing through the first heat medium heat exchanger 11a to become hot water, and then flows through the relay unit 2a to the load-side heat exchanger 30a of the load device 3Aa, where it is cooled by heat exchange with the indoor air in the indoor space. The cooled heat medium then flows to the second heat medium heat exchanger 21a, where it is heated by heat exchange with the refrigerant circulating through the second refrigerant circuit 20a, and then flows back into the first heat medium heat exchanger 11a.

[0083] In the second refrigerant circuit 20a, high-temperature, high-pressure gas refrigerant discharged from the second compressor 23a passes through the second flow switching valve 24a and flows to the second heat medium heat exchanger 21a, where it condenses and liquefies through heat exchange with the heat medium flowing in the first heat medium circuit 4a. The condensed and liquefied refrigerant is decompressed by the second expansion mechanism 25a to become a low-pressure gas-liquid two-phase refrigerant, and flows to the third heat medium heat exchanger 22a, where it exchanges heat with the heat medium flowing in the second heat medium circuit 5a to evaporate and gasify. The gasified refrigerant passes through the second flow switching valve 24a and is drawn into the second compressor 23a via an accumulator.

[0084] On the other hand, the heat medium flowing through the second heat medium circuit 5a is cooled by the refrigerant flowing through the third heat medium heat exchanger 22a to become cold water, and then flows into the load-side heat exchanger 30a of the load device 3Aa, where it is heated by heat exchange with the indoor air in the indoor space. The heated heat medium then flows into the third heat medium heat exchanger 22a again.

[0085] (Effects in Cooling-Dominated Operation) The refrigeration cycle apparatus 100 can more efficiently recover heat from the load device 3D that performs heating in cooling-dominated operation than the comparative example. This point will be described below.

[0086] Fig. 8 is a diagram showing temperature changes of the refrigerant and the heat medium in the evaporator of the second refrigerant circuit 20 during cooling-dominated operation of the refrigeration cycle apparatus 100 according to Embodiment 1. Fig. 9 is a diagram showing temperature changes of the refrigerant and the heat medium in the evaporator of the second refrigerant circuit during cooling-dominated operation of a comparative example. Fig. 10 is a diagram showing temperature changes of the refrigerant and the heat medium in the condenser of the second refrigerant circuit 20 during cooling-dominated operation of the refrigeration cycle apparatus 100 according to Embodiment 1. Fig. 11 is a diagram showing temperature changes of the refrigerant and the heat medium in the condenser of the second refrigerant circuit during cooling-dominated operation of a comparative example.

[0087] In Figures 8 to 11, the horizontal axis represents the position in the pipe length direction in the heat medium heat exchanger, and the vertical axis represents temperature. In Figures 8 to 9, the lines with left-pointing arrows represent the heat medium, and the lines with right-pointing arrows represent the refrigerant. In Figures 8 to 9, the temperature at the right end of the line representing the heat medium is the temperature of the heat medium at the inlet of the evaporator of the second refrigerant circuit, and the temperature at the left end of the line representing the heat medium is the temperature of the heat medium at the outlet of the evaporator of the second refrigerant circuit. In Figures 10 to 11, the lines with left-pointing arrows represent the refrigerant, and the lines with right-pointing arrows represent the heat medium. In Figures 10 to 11, the temperature at the left end of the line representing the heat medium is the temperature of the heat medium at the inlet of the condenser of the second refrigerant circuit, and the temperature at the right end of the line representing the heat medium is the temperature of the heat medium at the outlet of the condenser of the second refrigerant circuit. The temperatures in Figures 8 to 11 are merely examples and are not limited to the temperatures shown.

[0088] The heat recovery, specifically, the recovery of hot heat, from the heat medium that has passed through the load device 3D that performs heating is performed by a heat exchanger that functions as an evaporator in the second refrigerant circuit 20. During cooling-dominant operation, the heat exchanger that functions as an evaporator in the second refrigerant circuit 20 is the third heat medium heat exchanger 22. As shown in Figures 4 and 8 , the heat medium at 40°C that flows out from the load device 3D that performs heating flows into the third heat medium heat exchanger 22. Therefore, the refrigerant flowing through the third heat medium heat exchanger 22 exchanges heat with the heat medium at 40°C, thereby recovering hot heat from the heat medium at 40°C. The refrigerant that has recovered the hot heat flows to the second heat medium heat exchanger 21 that functions as a condenser in the second refrigerant circuit 20, and provides hot heat to the heat medium heading toward the load device 3D that performs heating in the second heat medium heat exchanger 21.

[0089] On the other hand, in the comparative example, the heat exchanger functioning as an evaporator in the second refrigerant circuit 20a is the second heat medium heat exchanger 21a. As shown in FIG. 6 , the heat medium flowing out from the load device 3Aa performing cooling flows into the second heat medium heat exchanger 21a. In the comparative example, as shown in FIG. 9 , the heat medium at 12°C flowing out from the load device 3Aa performing cooling flows into the second heat medium heat exchanger 21a functioning as an evaporator. Therefore, the refrigerant flowing through the second heat medium heat exchanger 21a exchanges heat with the heat medium at 12°C, thereby recovering heat from the heat medium at 12°C. The refrigerant from which the heat heat has been recovered flows to the third heat medium heat exchanger 22a functioning as a condenser in the second refrigerant circuit 20a, and provides heat to the heat medium flowing to the load device 3B performing heating in the third heat medium heat exchanger 22a.

[0090] Comparing the refrigeration cycle apparatus 100 with the comparative example, the comparative example recovers hot heat from a heat medium at 12°C, whereas the refrigeration cycle apparatus 100a recovers hot heat from a heat medium at 40°C. Therefore, the refrigeration cycle apparatus 100 can recover hot heat more efficiently than the comparative example, which recovers hot heat from a heat medium at 12°C. As the refrigeration cycle apparatus 100 can recover hot heat efficiently, it is possible to reduce the power consumption of the heat source machine 1 as a result, and energy efficiency is improved.

[0091] As described above, the comparative example has separate heat medium circuits connected to a load device that performs cooling and through which cold water circulates, and connected to a load device that performs heating and through which hot water circulates. In the comparative example, heat is provided to the refrigerant passing through the condenser of the second refrigerant circuit 20a by recovering heat from the heat medium at 12°C in the evaporator of the second refrigerant circuit 20a.

[0092] In contrast, the refrigeration cycle apparatus 100 has the same configuration as the comparative example, but the heat source unit 1 has a fourth heat medium heat exchanger 17. The refrigeration cycle apparatus 100 has a first heat medium circuit 4, a second heat medium circuit 5, and a third heat medium circuit 8, which are connected to each other by merging and branching to provide heat accommodation. Specifically, the refrigeration cycle apparatus 100 has a first heat medium circuit 4, a second heat medium circuit 5, and a third heat medium circuit 8, which are connected to each other at a merging point A and a branching point B. In this way, the refrigeration cycle apparatus 100 does not have independent heat medium circuits connected to load devices 3 that perform cooling and through which chilled water circulates, and heat medium circuits connected to load devices 3 that perform heating and through which hot water passes, but rather provides heat accommodation between the two circuits.

[0093] The refrigeration cycle apparatus 100 has the above configuration, and thus in cooling-dominated operation, it is possible to send a heat medium at a higher temperature (40°C in this case) than in the comparative example to the evaporator (third heat medium heat exchanger 22) in the relay unit 2. In cooling-dominated operation, the refrigeration cycle apparatus 100 generates high-temperature water in the fourth heat medium heat exchanger 17 and sends the high-temperature water to the condenser (second heat medium heat exchanger 21) in the relay unit 2 via the second heat medium circuit 5, thereby making it possible to send a heat medium at a higher temperature (40°C in this case) than in the comparative example to the evaporator (third heat medium heat exchanger 22) in the relay unit 2.

[0094] 8 and 9 show that the temperature of the heat medium flowing out from the condenser in the relay unit is the same, 45° C., in the refrigeration cycle apparatus 100 and the comparative example.

[0095] Below, we will explain, in comparison with a comparative example, why the fourth heat medium heat exchanger 17 generates high-temperature water and sends it to the condenser (second heat medium heat exchanger 21) in the relay unit 2, making it possible to send a heat medium at a higher temperature than in the comparative example to the evaporator (third heat medium heat exchanger 22) in the relay unit 2.

[0096] In the comparative example, the heat medium flowing out of the first heat medium heat exchanger 11a is passed through the load device 3Aa that performs cooling, and then passed through the evaporator (second heat medium heat exchanger 21a) in the relay unit 2a, and returned to the heat source unit 1a. Due to this flow of the heat medium, the refrigerant in the evaporator (second heat medium heat exchanger 21a) in the relay unit 2a recovers heat from the relatively low-temperature heat medium that has passed through the load device 3Aa that performs cooling.

[0097] In the refrigeration cycle apparatus 100, the heat medium flowing out of the first heat medium heat exchanger 11 passes through the load devices 3A, 3B, and 3C that perform cooling, and then returns to the first heat medium heat exchanger 11 of the heat source device 1 without passing through the second heat medium heat exchanger 21 and the third heat medium heat exchanger 22 in the relay unit 2. Because the heat medium flows in this manner in the refrigeration cycle apparatus 100, the evaporator (third heat medium heat exchanger 22) in the relay unit 2 does not recover heat from the relatively low-temperature heat medium that has passed through the load devices 3A, 3B, and 3C that perform cooling.

[0098] On the other hand, in the refrigeration cycle apparatus 100, the heat source unit 1 has a fourth heat medium heat exchanger 17, and first, high-temperature water is generated in the fourth heat medium heat exchanger 17 and sent to the condenser (second heat medium heat exchanger 21) in the relay unit 2. In this way, the refrigeration cycle apparatus 100 generates a 45°C heat medium in the condenser (second heat medium heat exchanger 21) by generating high-temperature water in the fourth heat medium heat exchanger 17 and sending it to the condenser (second heat medium heat exchanger 21) in the relay unit 2, and sends it to the load device 3D that performs heating. Then, the refrigeration cycle apparatus 100 sends the relatively high-temperature heat medium of 40°C after heat exchange with the indoor air in the load device 3D that performs heating to the evaporator (third heat medium heat exchanger 22).

[0099] If high-temperature water is not sent from the heat source unit 1 to the condenser (second heat medium heat exchanger 21) in the relay unit 2, it is necessary to use the heat medium at 40°C after passing through the load device 3D that performs heating as the heat medium to be sent to the condenser (second heat medium heat exchanger 21). For this reason, if high-temperature water is not sent from the heat source unit 1 to the condenser (second heat medium heat exchanger 21) in the relay unit 2, the relatively high-temperature heat medium at 40°C after passing through the load device 3D that performs heating cannot be sent to the evaporator (third heat medium heat exchanger 22).

[0100] In contrast, the refrigeration cycle apparatus 100 generates high-temperature water in the fourth heat medium heat exchanger 17 of the heat source unit 1 and sends it to the condenser (second heat medium heat exchanger 21) in the relay unit 2. Therefore, the refrigeration cycle apparatus 100 can send the heat medium at a relatively high temperature of 40°C after passing through the load device 3D that performs heating to the evaporator (third heat medium heat exchanger 22) rather than the condenser (second heat medium heat exchanger 21).

[0101] In this way, during cooling-dominated operation, the refrigeration cycle apparatus 100 can efficiently recover heat from the heating load device 3. As a result, the refrigeration cycle apparatus 100 can reduce the power consumption of the heat source unit 1 and improve energy efficiency.

[0102] (Operational Effects in Heating-Dominated Operation) The refrigeration cycle apparatus 100 can more efficiently recover cold energy from the load device 3D that performs cooling in heating-dominated operation than the comparative example. This point will be described below.

[0103] The heat recovery, specifically, the recovery of cold energy from the heat medium that has passed through the load device 3D that performs cooling, is performed by a heat exchanger that functions as a condenser in the second refrigerant circuit 20. During heating-dominant operation, the heat exchanger that functions as a condenser in the second refrigerant circuit 20 is the third heat medium heat exchanger 22. As shown in FIG. 5 , the heat medium at 12°C that flows out from the load device 3D that performs cooling flows into the third heat medium heat exchanger 22. Therefore, the refrigerant flowing through the third heat medium heat exchanger 22 exchanges heat with the heat medium at 12°C, thereby recovering cold energy from the heat medium at 12°C. The refrigerant that has recovered cold energy flows to the second heat medium heat exchanger 21 that functions as an evaporator in the second refrigerant circuit 20, and provides cold energy to the heat medium heading toward the load device 3D that performs cooling in the second heat medium heat exchanger 21.

[0104] On the other hand, in the comparative example, the heat exchanger functioning as a condenser in the second refrigerant circuit 20a is the second heat medium heat exchanger 21a. As shown in Fig. 7 , a heat medium at, for example, 40°C flowing out from the load device 3Ba that performs heating flows into the second heat medium heat exchanger 21a. Therefore, the refrigerant flowing through the second heat medium heat exchanger 21a exchanges heat with the heat medium at 40°C flowing out from the load device 3Ba that performs heating, thereby recovering cold from the heat medium at 40°C. The refrigerant from which the cold has been recovered flows to the third heat medium heat exchanger 22a that functions as an evaporator in the second refrigerant circuit 20a, and provides cold to the heat medium flowing to the load device 3B that performs cooling in the third heat medium heat exchanger 22a.

[0105] Comparing the refrigeration cycle apparatus 100 with the comparative example, the comparative example recovers cold energy from a heat medium at 40°C, whereas the refrigeration cycle apparatus 100a recovers cold energy from a heat medium at 12°C. Therefore, the refrigeration cycle apparatus 100 can recover cold energy more efficiently than the comparative example, which recovers cold energy from a heat medium at 40°C. As the refrigeration cycle apparatus 100 can recover cold energy efficiently, it is possible to reduce the power consumption of the heat source unit 1 and improve energy efficiency.

[0106] As described above, the comparative example has separate heat medium circuits connected to a load device that performs cooling and through which cold water circulates, and connected to a load device that performs heating and through which hot water circulates. In the comparative example, heat is recovered from the heat medium at 40°C in the condenser of the second refrigerant circuit 20a to provide cold to the refrigerant passing through the evaporator of the second refrigerant circuit 20a.

[0107] In contrast, in the refrigeration cycle apparatus 100, in addition to the configuration of the comparative example, the heat source unit 1 has a fourth heat medium heat exchanger 17. The refrigeration cycle apparatus 100 has a first heat medium circuit 4, a second heat medium circuit 5, and a third heat medium circuit 8, which are connected to each other by merging and branching. Specifically, the refrigeration cycle apparatus 100 has a first heat medium circuit 4, a second heat medium circuit 5, and a third heat medium circuit 8, which are connected to each other at a merging point A and a branching point B. In this way, in the refrigeration cycle apparatus 100, the heat medium circuit connected to the load device 3 that performs cooling and through which chilled water circulates and the heat medium circuit connected to the load device 3 that performs heating and through which hot water passes are not independent, and heat is shared between the two.

[0108] The refrigeration cycle apparatus 100 has the above configuration, and thus in heating-dominated operation, it is possible to send a heat medium at a temperature (12°C in this case) lower than that in the comparative example to the condenser (third heat medium heat exchanger 22) in the relay unit 2. In heating-dominated operation, the refrigeration cycle apparatus 100 produces low-temperature water in the fourth heat medium heat exchanger 17 and sends the low-temperature water to the evaporator (second heat medium heat exchanger 21) in the relay unit 2 via the second heat medium circuit 5, thereby making it possible to send a heat medium at a temperature (12°C in this case) lower than that in the comparative example to the condenser (third heat medium heat exchanger 22) in the relay unit 2.

[0109] Below, we will explain, in comparison with a comparative example, why the fourth heat medium heat exchanger 17 generates low-temperature water and sends it to the evaporator (second heat medium heat exchanger 21) in the relay unit 2, making it possible to send a heat medium at a lower temperature than in the comparative example to the condenser (third heat medium heat exchanger 22) in the relay unit 2.

[0110] In the comparative example, the heat medium flowing out of the first heat medium heat exchanger 11a is passed through the load device 3Ba that performs heating, and then passed through the evaporator (second heat medium heat exchanger 21a) in the relay unit 2a, and returned to the heat source unit 1a. Due to this flow of the heat medium, the refrigerant in the evaporator (second heat medium heat exchanger 21a) in the relay unit 2a recovers cold energy from the relatively high-temperature heat medium that has passed through the load device 3Aa that performs heating.

[0111] In the refrigeration cycle apparatus 100, the heat medium flowing out of the first heat medium heat exchanger 11 passes through the load devices 3A, 3B, and 3C that perform heating, and then returns to the first heat medium heat exchanger 11 of the heat source device 1 without passing through the second heat medium heat exchanger 21 and the third heat medium heat exchanger 22 in the relay unit 2. Because the heat medium flows in this manner in the refrigeration cycle apparatus 100, the condenser (third heat medium heat exchanger 22) in the relay unit 2 does not recover cold energy from the relatively high-temperature heat medium that has passed through the load devices 3A, 3B, and 3C that perform heating.

[0112] On the other hand, in the refrigeration cycle apparatus 100, the heat source unit 1 has a fourth heat medium heat exchanger 17, and first, low-temperature water is generated in the fourth heat medium heat exchanger 17 and sent to the evaporator (second heat medium heat exchanger 21) in the relay unit 2. In this way, the refrigeration cycle apparatus 100 generates a heat medium at 7°C in the evaporator (second heat medium heat exchanger 21) by generating low-temperature water in the fourth heat medium heat exchanger 17 and sending it to the evaporator (second heat medium heat exchanger 21) in the relay unit 2, and sends it to the load device 3D that performs cooling. Then, the refrigeration cycle apparatus 100 sends the heat medium at a relatively low temperature of 12°C after heat exchange with indoor air in the load device 3D that performs cooling to the condenser (third heat medium heat exchanger 22).

[0113] If low-temperature water is not sent from the heat source unit 1 to the evaporator (second heat medium heat exchanger 21) in the relay unit 2, it is necessary to use the heat medium at 12°C after passing through the load device 3D that performs cooling as the heat medium to be sent to the evaporator (second heat medium heat exchanger 21). For this reason, if low-temperature water is not sent from the heat source unit 1 to the evaporator (second heat medium heat exchanger 21) in the relay unit 2, the relatively low-temperature heat medium at 12°C after passing through the load device 3D that performs cooling cannot be sent to the condenser (third heat medium heat exchanger 22).

[0114] In contrast, the refrigeration cycle apparatus 100 generates low-temperature water in the fourth heat medium heat exchanger 17 of the heat source unit 1 and sends it to the evaporator (second heat medium heat exchanger 21) in the relay unit 2. Therefore, the refrigeration cycle apparatus 100 can send the heat medium at a relatively low temperature of 12°C after passing through the load device 3D that performs cooling to the condenser (third heat medium heat exchanger 22) rather than the evaporator (second heat medium heat exchanger 21).

[0115] In this way, during heating-dominated operation, the refrigeration cycle apparatus 100 can efficiently recover cold energy from the load device 3 that performs cooling. As a result, the refrigeration cycle apparatus 100 can reduce the power consumption of the heat source unit 1 and improve energy efficiency.

[0116] The refrigeration cycle device 100 is not limited to the structure shown in FIGS. 1 to 5, and can be modified as follows, for example, without departing from the gist of the present disclosure.

[0117] In the refrigeration cycle apparatus 100, all of the load devices 3 may be indoor units, or may be hot water storage tanks for supplying hot water to some or all of the multiple load devices 3. In the refrigeration cycle apparatus 100, when the load devices 3 are hot water storage tanks, the heat medium flowing through the heat medium circuit is water supplied to the hot water storage tanks that are the load devices 3. The hot water storage tanks store water supplied via a water supply pipe (not shown). The hot water storage tanks store hot water heated by the heat source unit 1, the relay unit 2, or the relay unit 2. When the load devices 3 are hot water storage tanks, hot water storage is performed, for example, in the same operation as the heating operation of the load devices 3 described above.

[0118] In the refrigeration cycle apparatus 100 described above, the second refrigerant circuit 20 includes a second flow path switching valve 24. The second refrigerant circuit 20 is configured to be switchable between a flow direction in which the refrigerant sequentially flows through the second compressor 23, the second heat medium heat exchanger 21, the second expansion mechanism 25, and the third heat medium heat exchanger 22, and a flow direction in which the refrigerant sequentially flows through the second compressor 23, the third heat medium heat exchanger 22, the second expansion mechanism 25, and the second heat medium heat exchanger 21. As shown in the following Figures 12 and 13 , the refrigeration cycle apparatus 100 may be configured such that the second flow path switching valve 24 is eliminated from the second refrigerant circuit 20, and the refrigerant circulates in only one direction in the second refrigerant circuit 20.

[0119] Fig. 12 is a refrigerant circuit diagram showing the flow of a heat medium in cooling-dominated operation in a modified example of the refrigeration cycle apparatus 100 according to Embodiment 1. Fig. 13 is a refrigerant circuit diagram showing the flow of a heat medium in heating-dominated operation in a modified example of the refrigeration cycle apparatus 100 according to Embodiment 1. The modified refrigeration cycle apparatus 100 shown in Figs. 12 and 13 has the second flow path switching valve 24 deleted from the configuration shown in Fig. 1 etc. Furthermore, the modified refrigeration cycle apparatus 100 shown in Figs. 12 and 13 has a third flow path switching device 90 added to the configuration shown in Fig. 1 etc.

[0120] In the second refrigerant circuit 20, the refrigerant circulates through the second compressor 23, the second heat medium heat exchanger 21, the second expansion mechanism 25, and the third heat medium heat exchanger 22 in this order, with the second heat medium heat exchanger 21 functioning as a condenser and the third heat medium heat exchanger 22 functioning as an evaporator. In the second refrigerant circuit 20, the refrigerant circulates through the second compressor 23, the third heat medium heat exchanger 22, the second expansion mechanism 25, and the second heat medium heat exchanger 21 in this order, with the third heat medium heat exchanger 22 functioning as a condenser and the second heat medium heat exchanger 21 functioning as an evaporator.

[0121] The third flow path switching device 90 has multiple third flow path switching valves 90a. The third flow path switching valves 90a are, for example, three-way valves and have a function of switching the flow path of the heat medium. In the cooling-dominated operation shown in FIG. 12 , the third flow path switching device 90 switches the third flow path switching valve 90a to form a heat medium flow path so that the heat medium flows into the load device 3D performing heating from the second heat medium heat exchanger 21 functioning as a condenser, and the heat medium flows out from the load device 3D performing heating to the third heat medium heat exchanger 22 functioning as an evaporator. In the heating-dominated operation shown in FIG. 13 , the third flow path switching device 90 switches the third flow path switching valve 90a to form a heat medium flow path so that the heat medium flows into the load device 3D performing cooling from the third heat medium heat exchanger 22 functioning as an evaporator, and the heat medium flows out from the load device 3D performing cooling to the second heat medium heat exchanger 21 functioning as a condenser.

[0122] In the illustrated example, the third flow path switching device 90 has five third flow path switching valves 90a, but the number of third flow path switching valves 90a is not limited to five. Furthermore, the third flow path switching device 90 is not limited to being configured with only three-way valves, and may be configured with a combination of two-way valves and three-way valves. In short, the number and combination of valves in the third flow path switching device 90 are not limited as long as the above-described flow of the heat medium can be formed.

[0123] In this way, the refrigeration cycle apparatus 100 may be configured such that the second refrigerant circuit 20 circulates the refrigerant in one direction.

[0124] As described above, the refrigeration cycle apparatus 100 of the first embodiment includes a heat source unit 1, a relay unit 2 connected to the heat source unit 1, and a plurality of load devices 3 connected to the relay unit 2. The heat source unit 1 includes a first refrigerant circuit 10 through which a refrigerant circulates. The first refrigerant circuit 10 has a first heat medium heat exchanger 11 that exchanges heat between the refrigerant flowing through the first refrigerant circuit 10 and a heat medium flowing therein. The relay unit 2 includes a second refrigerant circuit 20 through which a refrigerant circulates. The second refrigerant circuit 20 has a second heat medium heat exchanger 21 that exchanges heat between the refrigerant flowing through the second refrigerant circuit 20 and the heat medium flowing therein, and a third heat medium heat exchanger 22 that exchanges heat between the refrigerant flowing through the second refrigerant circuit 20 and the heat medium flowing therein. The first heat medium heat exchanger 11 and the plurality of load devices 3 are connected by first heat medium piping 40 to form a first heat medium circuit 4 through which a heat medium circulates. The heat source unit 1 further includes a fourth heat medium heat exchanger 17 that exchanges heat between the refrigerant flowing through the first refrigerant circuit 10 and the heat medium flowing therein. The heat source unit 1 includes a second heat medium circuit 5 and a third heat medium circuit 8. The second heat medium circuit 5 includes the fourth heat medium heat exchanger 17, a second heat medium heat exchanger 21, a plurality of load devices 3, and a third heat medium heat exchanger 22, connected in this order by second heat medium piping 50, and the downstream side of the third heat medium heat exchanger merges with the first heat medium piping 40 between the downstream side of the plurality of load devices 3 and the upstream side of the first heat medium heat exchanger 11. The third heat medium circuit 8 includes the second heat medium circuit 5 and a third heat medium piping 80 that branches off from the first heat medium circuit 4 upstream of the first heat medium heat exchanger 11 and is connected to the fourth heat medium heat exchanger 17.

[0125] With the above-described configuration, the refrigeration cycle apparatus 100 has the first heat medium circuit 4, the second heat medium circuit 5, and the third heat medium circuit 8, and these circuits merge and branch and are connected to each other for heat accommodation. Therefore, the refrigeration cycle apparatus 100 can effectively utilize the heat quantity recovered from the heat medium that has passed through the load device 3, and can reduce power consumption.

[0126] The second heat medium piping 50 merges with the first heat medium piping 40 between the plurality of load devices 3 and the first heat medium heat exchanger 11 inside the relay unit 2, and the third heat medium piping 80 is connected to the first heat medium piping 40 so as to branch off from the upstream of the first heat medium heat exchanger 11 of the first heat medium circuit 4 inside the heat source unit 1.

[0127] With the above configuration, the refrigeration cycle apparatus 100 can be configured such that the heat source unit 1 and the relay unit 2 are connected by three pipes.

[0128] The refrigeration cycle apparatus 100 includes a control device 101 that controls a heat source unit 1, a relay unit 2, and a plurality of load devices 3. The refrigeration cycle apparatus 100 includes a first flow path switching device 6a that is provided in a first heat medium circuit 4 and a second heat medium circuit 5 and that switches the flow path of the heat medium flowing into the plurality of load devices 3 to the first heat medium circuit 4 or the second heat medium circuit 5. The refrigeration cycle apparatus 100 includes a second flow path switching device 6b that is provided in the first heat medium circuit 4 and the second heat medium circuit 5 and that switches the flow path of the heat medium flowing out of the plurality of load devices 3 to the first heat medium circuit 4 or the second heat medium circuit 5. When the plurality of load devices 3 are in a cooling-dominated operation mode in which heating operation and cooling operation are mixed and the cooling load is larger than the heating load, the control device 101 switches the first flow path switching device 6a and the second flow path switching device 6b so that at least one load device 3 performing a heating operation among the plurality of load devices 3 is connected to the second heat medium circuit 5. When the control device 101 is in a heating-dominated operation mode in which heating and cooling operations are mixed in multiple load devices 3 and the heating load is larger than the cooling load, the control device 101 switches the first flow path switching device 6a and the second flow path switching device 6b so that at least one load device 3 performing cooling operation among the multiple load devices 3 is connected to the second heat medium circuit 5.

[0129] With the above configuration, when the refrigeration cycle apparatus 100 is in a cooling-dominated operation mode, the refrigeration cycle apparatus 100 can effectively utilize the heat recovered from the heat medium that has passed through the load device 3 that is performing a heating operation, thereby reducing power consumption. Also, when the refrigeration cycle apparatus 100 is in a heating-dominated operation mode, the refrigeration cycle apparatus 100 can effectively utilize the heat recovered from the heat medium that has passed through the load device 3 that is performing a cooling operation, thereby reducing power consumption.

[0130] The first refrigerant circuit 10 includes at least a first compressor 12, a first flow switching valve 13, a heat source side heat exchanger 14, a first expansion mechanism 15, a first heat medium heat exchanger 11, a third expansion mechanism 18, and a fourth heat medium heat exchanger 17. The second refrigerant circuit 20 includes at least a second compressor 23, a second heat medium heat exchanger 21, a second expansion mechanism 25, and a third heat medium heat exchanger 22. The second refrigerant circuit 20 may include a second flow switching valve 24 that switches the flow direction of the refrigerant discharged from the second compressor 23 to the second heat medium heat exchanger 21 or the third heat medium heat exchanger 22, or may be configured to circulate in only one direction. When the second refrigerant circuit 20 is configured to circulate in only one direction, the refrigeration cycle apparatus 100 includes a third flow switching device 90 that switches the flow path of the heat medium.

[0131] With the above configuration, the refrigeration cycle apparatus 100 can effectively utilize the heat recovered from the heat medium that has passed through the load device 3, thereby reducing power consumption.

[0132] 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 .

[0133] With the above configuration, the refrigeration cycle device 100 can improve operating efficiency compared to a configuration in which the amount of refrigerant circulating in the first refrigerant circuit 10 is less than the amount of refrigerant circulating in the second refrigerant circuit 20.

[0134] Although the refrigeration cycle apparatus 100 has been described above based on the embodiment, the refrigeration cycle apparatus 100 is not limited to the configuration of the above-described embodiment. The configuration of the refrigeration cycle apparatus 100 described above is an example, and other components may be included, or some components may be omitted. In short, the refrigeration cycle apparatus 100 includes a range of design modifications and application variations that are normally made by a person skilled in the art, as long as they do not deviate from the technical concept thereof.

[0135] 1 Heat source machine, 1a Heat source machine, 2 Relay machine, 2a Relay machine, 3 Load device, 3A Load device, 3Aa Load device, 3B Load device, 3Ba Load device, 3C Load device, 3D Load device, 4 First heat medium circuit, 4a First heat medium circuit, 4aa First flow switching device, 5 Second heat medium circuit, 5a Second heat medium circuit, 5aa First flow switching device, 6a First flow switching device, 6b Second flow switching device, 8 Third heat medium circuit, 9 Flow switching device, 10 First refrigerant circuit, 10a First refrigerant circuit, 11 First heat medium heat exchanger, 11a First heat medium heat exchanger, 12 First compressor, 12a First compressor, 13 First flow switching valve, 13a First flow switching valve, 14 Heat source side heat exchanger, 14a Heat source side heat exchanger, 15 First expansion mechanism, 15a First expansion mechanism, 16 heat source side blower, 17 fourth heat medium heat exchanger, 18 third expansion mechanism, 20 second refrigerant circuit, 20a second refrigerant circuit, 21 second heat medium heat exchanger, 21a second heat medium heat exchanger, 22 third heat medium heat exchanger, 22a third heat medium heat exchanger, 23 second compressor, 23a second compressor, 24 second flow path switching valve, 24a second flow path switching valve, 25 second expansion mechanism, 25a second expansion mechanism, 30 load side heat exchanger, 30a load side heat exchanger, 31 load side blower, 40 first heat medium piping, 41 pump, 50 second heat medium piping, 80 third heat medium piping, 90 third flow path switching device, 90a third flow path switching valve, 100 refrigeration cycle device, 100a refrigeration cycle device, 101 control device, A junction point, B branch point, C Confluence point.

Claims

1. A refrigeration cycle apparatus comprising a heat source machine, a relay machine connected to the heat source machine, and a plurality of load devices connected to the relay machine, wherein the heat source machine comprises a first refrigerant circuit through which a refrigerant circulates, the first refrigerant circuit having a first heat medium heat exchanger that exchanges heat between the refrigerant flowing in the first refrigerant circuit and a heat medium flowing therein; the relay machine comprises a second refrigerant circuit through which a refrigerant circulates, the second refrigerant circuit having a second heat medium heat exchanger that exchanges heat between the refrigerant flowing in the second refrigerant circuit and the heat medium flowing therein, and a third heat medium heat exchanger that exchanges heat between the refrigerant flowing in the second refrigerant circuit and the heat medium flowing therein; the first heat medium heat exchanger and the plurality of load devices are connected by first heat medium piping to form a first heat medium circuit through which a heat medium circulates; and the heat source machine further comprises a fourth heat medium heat exchanger that exchanges heat between the refrigerant flowing in the first refrigerant circuit and the heat medium flowing therein. the fourth heat medium heat exchanger, the second heat medium heat exchanger, the plurality of load devices, and the third heat medium heat exchanger are connected in this order by second heat medium piping, and a second heat medium circuit is formed in which a downstream side of the third heat medium heat exchanger joins the first heat medium piping between the downstream side of the plurality of load devices and the upstream side of the first heat medium heat exchanger; and a third heat medium circuit is formed in which a third heat medium piping branches off from the first heat medium circuit upstream of the first heat medium heat exchanger and is connected to the fourth heat medium heat exchanger.

2. The refrigeration cycle apparatus according to claim 1, wherein the second heat medium piping joins the first heat medium piping between the plurality of load devices and the first heat medium heat exchanger inside the relay unit, and the third heat medium piping is connected to the first heat medium piping so as to branch off from an upstream side of the first heat medium heat exchanger of the first heat medium circuit inside the heat source unit.

3. A control device for controlling the heat source unit, the relay unit, and the plurality of load devices; a first flow path switching device provided in the first heat medium circuit and the second heat medium circuit, for switching the flow path of the heat medium flowing into the plurality of load devices to the first heat medium circuit or the second heat medium circuit; and a second flow path switching device provided in the first heat medium circuit and the second heat medium circuit, for switching the flow path of the heat medium flowing out of the plurality of load devices to the first heat medium circuit or the second heat medium circuit, wherein the control device switches the first flow path switching device and the second flow path switching device so that a load device performing a heating operation among the plurality of load devices is connected to the second heat medium circuit when the plurality of load devices are performing a mixture of heating and cooling operations and in a cooling-dominated operation mode in which the cooling load is larger than the heating load; and when the plurality of load devices are performing a mixture of heating and cooling operations and in a heating-dominated operation mode in which the heating load is larger than the cooling load, 3. The refrigeration cycle apparatus according to claim 1, wherein the first flow path switching device and the second flow path switching device are switched so that a load device performing cooling operation among the plurality of load devices is connected to the second heat medium circuit.

4. A refrigeration cycle device according to any one of claims 1 to 3, wherein the first refrigerant circuit comprises at least a first compressor, a first flow switching valve, a heat source side heat exchanger, a first expansion mechanism, the first heat medium heat exchanger, a third expansion mechanism and the fourth heat medium heat exchanger, and the second refrigerant circuit comprises at least a second compressor, the second heat medium heat exchanger, a second expansion mechanism and the third heat medium heat exchanger.

5. A refrigeration cycle device according to claim 4, wherein the second refrigerant circuit is provided with a second flow path switching valve that switches the flow direction of the refrigerant discharged from the second compressor to the second heat medium heat exchanger or the third heat medium heat exchanger.

6. A refrigeration cycle device according to claim 4, wherein the second refrigerant circuit is connected in sequence by refrigerant piping so that the refrigerant flows through the second compressor, the second heat medium heat exchanger, the second expansion mechanism, and the third heat medium heat exchanger in that order, or the refrigerant flows through the second compressor, the third heat medium heat exchanger, the second expansion mechanism, and the second heat medium heat exchanger in that order.

7. A refrigeration cycle apparatus according to claim 6, which is dependent on claim 3, comprising a third flow path switching device that switches the flow path of the heat medium, wherein the third flow path switching device forms a heat medium flow path such that in the cooling-dominated operation mode, the source of the heat medium flowing into a load device that performs heating among the plurality of load devices is one of the second heat medium heat exchanger and the third heat medium heat exchanger that functions as a condenser, and the destination of the heat medium flowing from a load device that performs heating among the plurality of load devices is one of the second heat medium heat exchanger and the third heat medium heat exchanger that functions as an evaporator, and in the heating-dominated operation mode, the source of the heat medium flowing into a load device that performs cooling among the plurality of load devices is one of the second heat medium heat exchanger and the third heat medium heat exchanger that functions as an evaporator, and the destination of the heat medium flowing from a load device that performs cooling among the plurality of load devices is one of the second heat medium heat exchanger and the third heat medium heat exchanger that functions as a condenser.

8. A refrigeration cycle device according to any one of claims 1 to 7, wherein the first heat medium circuit is provided with at least one pump for circulating the heat medium, and the at least one pump is provided in one of the heat source unit and the relay unit.

9. A refrigeration cycle device according to any one of claims 1 to 8, wherein the first heat medium circuit is provided with at least one pump for circulating the heat medium, and the at least one pump is a plurality of pumps, and is provided in at least one of the heat source unit and the relay unit, and in some or all of the plurality of load devices.

10. A refrigeration cycle device according to any one of claims 1 to 9, wherein the amount of refrigerant circulating in the first refrigerant circuit is greater than the amount of refrigerant circulating in the second refrigerant circuit.

11. A refrigeration cycle device according to any one of claims 1 to 10, wherein the first refrigerant circuit is filled with a flammable refrigerant, and the second refrigerant circuit is filled with a non-flammable or slightly flammable refrigerant.

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