Refrigeration cycle device

Abstract

This refrigeration cycle device comprises a heat source unit, a relay unit, and three or more load devices. The heat source unit comprises a first refrigerant circuit through which a refrigerant circulates, and the first refrigerant circuit has a first heat-medium heat exchanger. The relay unit comprises a second refrigerant circuit through which the refrigerant circulates, and the second refrigerant circuit has a second heat-medium heat exchanger and a third heat-medium heat exchanger. The refrigeration cycle device has formed therein: a first heat medium circuit through which a heat medium circulates and in which the first heat-medium heat exchanger, the second heat-medium heat exchanger, and at least two or more of the load devices among the three or more load devices are connected by first heat medium piping; a second heat medium circuit through which the heat medium circulates and in which the third heat-medium heat exchanger and at least two or more of the load devices are connected by second heat medium piping; and a third heat medium circuit through which the heat medium circulates, without passing through the relay unit, to the first heat-medium heat exchanger and to another load device among the three or more load devices.

Description

Refrigeration cycle equipment

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

[0002] Conventionally, as an example of a refrigeration cycle device, there is an air conditioner having an outdoor unit as a heat source unit, a relay unit connected to the outdoor unit, and a plurality of indoor units connected to the relay unit (see, for example, Patent Document 1). The air conditioner of Patent Document 1 is configured to allow each indoor unit to freely select heating or cooling using chilled water and hot water produced in the relay unit, and to enable simultaneous cooling and heating operation.

[0003] International Publication No. 2014 / 097870

[0004] In an air conditioner, some of the multiple indoor units may be operated in either heating or cooling mode. For example, multiple indoor units installed in a building corridor may be operated in either heating or cooling mode depending on the season. A group of indoor units operated in either heating or cooling mode in this way does not need to operate in both heating and heating mode simultaneously.

[0005] In the air conditioner of Patent Document 1, all of the indoor units are connected to the heat source unit via a relay unit, and all of the indoor units are capable of simultaneous cooling and heating operation. In the air conditioner of Patent Document 1, the indoor units that do not require simultaneous cooling and heating operation are also connected to the heat source unit via a relay unit, which ultimately leads to higher costs.

[0006] The present disclosure is made to solve the above-mentioned problems, and has an object to provide a refrigeration cycle device that enables simultaneous cooling and heating operation while reducing costs.

[0007] 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 three or more load devices, 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 through the first refrigerant circuit and a heat medium flowing therein, the relay unit includes 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 through the second refrigerant circuit and the heat medium flowing therein, and a second heat medium heat exchanger that exchanges heat between the refrigerant flowing through the second refrigerant circuit and the heat medium flowing therein. and a third heat medium heat exchanger connected to the first heat medium heat exchanger and at least two of the three or more load devices by a first heat medium piping to form a first heat medium circuit through which the heat medium circulates, a second heat medium circuit through which the third heat medium heat exchanger and at least two of the three or more load devices are connected by a second heat medium piping to form a third heat medium circuit through which the heat medium circulates, without passing through a relay device.

[0008] The refrigeration cycle apparatus according to the present disclosure includes a heat source unit, a relay unit, and three or more load devices, and is capable of simultaneous cooling and heating operation in at least two of the three or more load devices. Other load devices among the three or more load devices do not require simultaneous cooling and heating operation and are connected directly to the first heat medium heat exchanger of the heat source unit without going through the relay unit. By connecting the other load devices directly to the first heat medium heat exchanger of the heat source unit without going through the relay unit, the overall configuration of the refrigeration cycle apparatus can be simplified. As a result, the refrigeration cycle apparatus can achieve simultaneous cooling and heating operation while reducing costs.

[0009] Fig. 1 is a refrigerant circuit diagram of a refrigeration cycle device according to embodiment 1. Fig. 2 is a refrigerant circuit diagram of the refrigeration cycle device according to embodiment 1, showing the flows of refrigerant and heat medium when all load devices perform cooling. Fig. 3 is a refrigerant circuit diagram of the refrigeration cycle device according to embodiment 1, showing the flows of refrigerant and heat medium when all load devices perform heating. Fig. 4 is a refrigerant circuit diagram of the refrigeration cycle device according to embodiment 1, showing the flows of refrigerant and heat medium when cooling is the dominant operation. Fig. 5 is a refrigerant circuit diagram of the refrigeration cycle device according to embodiment 1, showing the flows of refrigerant and heat medium when heating is the dominant operation. Fig. 6 is a refrigerant circuit diagram of a refrigeration cycle device according to embodiment 1, showing the flows of refrigerant and heat medium when heating is the dominant operation. Fig. 7 is a refrigerant circuit diagram of a refrigeration cycle device according to embodiment 1, showing a first modified example. Fig. 8 is a refrigerant circuit diagram of a refrigeration cycle device according to embodiment 2.

[0010] 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.

[0011] 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 100 according to Embodiment 1 includes a heat source unit 1, a relay unit 2 connected to the heat source unit 1, two load devices 3A and 3B connected to the heat source unit 1 via the relay unit 2, and two load devices 3C and 3D connected directly to the heat source unit 1. The heat source unit 1 is, for example, an outdoor unit. The load devices 3A, 3B, 3C, and 3D are, for example, indoor units that supply temperature-controlled air to a room. The heat source unit 1 is installed, for example, on the roof of a building. The relay unit 2 and the load devices 3A, 3B, 3C, and 3D are installed, for example, inside the building. The components constituting the heat source unit 1, the relay unit 2, and the load devices 3A, 3B, 3C, and 3D are controlled by a control device 101. 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 device 3.

[0012] The refrigeration cycle apparatus 100 has a configuration in which at least two or more of the three or more load devices 3 are connected to the heat source machine 1 via the relay unit 2, and the other load devices 3 of the three or more load devices 3 are connected directly to the heat source machine 1 without going through the relay unit 2. In the example shown, there are four load devices 3, two of which, load devices 3A and 3B, are connected to the heat source machine 1 via the relay unit 2, and the other two, load devices 3C and 3D, are connected directly to the heat source machine 1 without going through the relay unit 2. It is sufficient that there are at least two or more load devices 3 connected to the heat source machine 1 via the relay unit 2. It is also sufficient that there is at least one or more load devices 3 connected directly to the heat source machine 1 without going through the relay unit 2.

[0013] The refrigeration cycle apparatus 100 has a configuration in which load devices 3A and 3B connected to the heat source unit 1 via a relay unit 2 and load devices 3C and 3D connected directly to the heat source unit 1 are mixed. In the refrigeration cycle apparatus 100, only the load devices 3A and 3B connected to the heat source unit 1 via the relay unit 2 are capable of simultaneous cooling and heating operation. The load devices 3C and 3D connected directly to the heat source unit 1 without going through the relay unit 2 are not capable of simultaneous cooling and heating operation. The refrigeration cycle apparatus 100 has a configuration in which the load devices 3C and 3D that do not need to be capable of simultaneous cooling and heating operation are connected directly to the heat source unit 1 without going through the relay unit 2, thereby reducing costs. Furthermore, the refrigeration cycle apparatus 100 has a configuration in which the heat source unit 1 and the relay unit 2 are connected by two pipes, allowing simultaneous cooling and heating operation, while maintaining ease of installation.

[0014] 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 has a first heat medium heat exchanger 11 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 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 load device 3 includes a load-side heat exchanger 30.

[0015] The first refrigerant circuit 10 contains, for example, R290, NH ３ 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 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. ３For example, the refrigerant sealed 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.

[0016] 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, to improve operating efficiency, the amount of refrigerant circulating through the first refrigerant circuit 10 is greater than the amount of refrigerant circulating through the second refrigerant circuit 20.

[0017] In the refrigeration cycle apparatus 100, the first heat medium heat exchanger 11, the second heat medium heat exchanger 21, and the load side heat exchanger 30 are connected by a first heat medium pipe 40 to form a first heat medium circuit 4 through which the heat medium circulates. In the refrigeration cycle apparatus 100, the third heat medium heat exchanger 22 and the load side heat exchanger 30 are connected by a second heat medium pipe 50 to form a second heat medium circuit 5 through which the heat medium circulates. The first heat medium circuit 4 and the second heat medium circuit 5 are provided with a flow path switching device 6 that switches the flow path of the heat medium flowing into the load device 3 between the first heat medium circuit 4 and the second heat medium circuit 5. The heat medium is, for example, water, brine, or a mixture of brine and water.

[0018] First, the 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, and a first heat medium heat exchanger 11. The first refrigerant circuit 10 includes 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, which are sequentially connected by refrigerant piping. Note that the first refrigerant circuit 10 may include other components in addition to the above-described components, or may omit some components.

[0019] 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 or the first heat medium heat exchanger 11 via the first flow path switching valve 13.

[0020] The first flow path switching valve 13 is, for example, a four-way valve and has a function of switching the refrigerant flow path. During cooling operation, the first flow path switching valve 13 connects the refrigerant discharge side of the first compressor 12 to the heat source side heat exchanger 14 and switches the refrigerant flow path to connect the refrigerant suction side of the first compressor 12 to the first heat medium heat exchanger 11. 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. The first flow path switching valve 13 may be configured as a combination of two-way valves or three-way valves.

[0021] 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.

[0022] 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.

[0023] 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 heat medium, evaporating the refrigerant and gasifying the refrigerant, thereby 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, thereby heating the heat medium.

[0024] 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 a flow path switching device 6 that switches the flow path of the heat medium flowing into the load device 3 between the first heat medium circuit 4 and the second heat medium circuit 5. The second refrigerant circuit 20 includes a second compressor 23, a second flow path switching valve 24, the second heat medium heat exchanger 21, a second expansion mechanism 25, and the third heat medium heat exchanger 22, which are connected in sequence by refrigerant piping. Note that the second refrigerant circuit 20 may include other components in addition to the above-described components, or may omit some components.

[0025] 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.

[0026] The second flow path switching valve 24 is, for example, a four-way valve and has basically the same configuration as the first flow path switching valve 13. During cooling operation, the second flow path switching valve 24 switches the refrigerant flow path to connect the refrigerant discharge side of the second compressor 23 to the second heat medium heat exchanger 21 and 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 switches the refrigerant flow path to connect the refrigerant discharge side of the second compressor 23 to the third heat medium heat exchanger 22 and 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.

[0027] 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.

[0028] 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 a flow path for the first heat medium circuit 4. That is, the second heat medium heat exchanger 21 serves as a component of the second refrigerant circuit 20 and a component of the first heat medium circuit 4. 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 circulating through the first heat medium circuit 4 flow in counterflow directions to increase the heat exchange rate in the second heat medium heat exchanger 21.

[0029] 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 circulating through the first heat medium pipe 40, 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 circulating through the first heat medium pipe 40, evaporating the refrigerant to vaporize it and cooling the heat medium.

[0030] 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 the third heat medium heat exchanger 22 shown in FIG. 1 , particularly when functioning as a condenser, it is preferable to configure the piping so that the refrigerant circulating through the second refrigerant circuit 20 and the heat medium circulating through the second heat medium circuit 5 flow in counterflow directions to increase the heat exchange rate in the third heat medium heat exchanger 22.

[0031] 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 circulating through the second heat medium pipe 50, 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 circulating through the second heat medium pipe 50, condensing the refrigerant to liquefy or convert it into a gas-liquid two-phase state, and heating the heat medium.

[0032] The flow path switching device 6 includes a flow path switching device 6a and a flow path switching device 6b. The flow path 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 inflow side of the load-side heat exchanger 30. The flow path switching device 6a switches the flow path of the heat medium. The flow path switching device 6a switches the inflow 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.

[0033] The flow path switching device 6a is configured as a three-way valve. The three-way valve configuring the flow path switching device 6a has three ports connected to the first heat medium heat exchanger 11, the third heat medium heat exchanger 22, and the load-side heat exchanger 30. The three-way valve configuring the 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 third heat medium heat exchanger 22 communicates with the port connected to the load-side heat exchanger 30. The flow path switching device 6a is controlled by the control device 101. The 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 openings (opening areas) can be controlled.

[0034] The 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 flow path switching device 6b switches the flow path of the heat medium. The 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.

[0035] Here, the flow path switching device 6b is configured as a three-way valve. The three-way valve configuring the flow path switching device 6b has three ports connected to the second heat medium heat exchanger 21, the third heat medium heat exchanger 22, and the load-side heat exchanger 30. The three-way valve configuring the flow path switching device 6b is switchable between a first 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, 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. The flow path switching device 6b is controlled by the control device 101. The 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 openings (opening areas) can be controlled.

[0036] When the flow path switching devices 6a and 6b connected to the load device 3 are in the first state, the load device 3 becomes a device that constitutes the first heat medium circuit 4. When the flow path switching devices 6a and 6b connected to the load device 3 are in the second state, the load device 3 becomes a device that constitutes the second heat medium circuit 5.

[0037] The first heat medium circuit 4 is provided with a first pump 41 that circulates the heat medium. The first pump 41 is one of the devices that constitute the first heat medium circuit 4, and is provided in the heat source unit 1, as an example. The first pump 41 draws water in the first heat medium circuit 4, applies pressure to it, and sends it out to circulate. The capacity of the first pump 41 is changed by a pump inverter drive device (not shown). The pump inverter drive device changes the capacity of the first pump 41 by arbitrarily changing the drive frequency based on instructions from the control device 101.

[0038] The first pump 41 may be provided in the heat source unit 1 or in the relay unit 2. Furthermore, the first pump 41 may be provided in both the heat source unit 1 and the relay unit 2. The refrigeration cycle apparatus 100 shown in FIG. 1 is configured such that one first 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.

[0039] The second heat medium circuit 5 is also provided with a second pump 51 for circulating the heat medium. The second pump 51 is one of the components constituting the second heat medium circuit 5. The second pump 51 draws water in the second heat medium circuit 5, applies pressure to it, and sends it out to circulate. The capacity of the second pump 51 is changed by a pump inverter drive device (not shown). The pump inverter drive device changes the capacity of the second pump 51 by arbitrarily changing the drive frequency based on instructions from the control device 101.

[0040] The second pump 51 has a smaller flow rate or head than the first pump 41. This is because the second heat medium circuit 5 connects the relay unit 2 and the load devices 3A and 3B, and has shorter heat medium piping than the first heat medium circuit 4, so pressure loss is not as large. Making the second pump 51 smaller than the first pump 41 reduces costs and the burden of installation work. The second pump 51 may have the same flow rate or head as the first pump 41.

[0041] The load device 3 includes a load-side heat exchanger 30 and a load-side blower 31. The load device 3 passes air in the indoor space through the load-side heat exchanger 30, generating an air flow that is returned 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 cooler than the air passes through the heat transfer tubes of the load-side heat exchanger 30, thereby cooling the indoor space. On the other hand, during heating operation, a heat medium that is warmer than the air passes through the heat transfer tubes of the load-side heat exchanger 30, thereby heating the indoor space.

[0042] As described above, the load devices 3A and 3B are connected to the first heat medium heat exchanger 11 of the heat source unit 1 via the first heat medium circuit 4 and the second heat medium circuit 5. The load devices 3C and 3D are connected to the first heat medium heat exchanger 11 of the heat source unit 1 via the third heat medium circuit 7. The load devices 3C and 3D are connected to the first heat medium heat exchanger 11 so that the heat medium circulates between the load devices 3C and 3D and the first heat medium heat exchanger 11 without passing through the relay unit 2.

[0043] The third heat medium circuit 7 is a circuit in which the heat medium circulates between the first heat medium heat exchanger 11 and the load devices 3C and 3D without passing through the relay unit 2. The third heat medium circuit 7 has a third heat medium piping 70 that passes the heat medium through the load devices 3C and 3D. One end of the third heat medium piping 70 is connected to the first heat medium piping 40 between the downstream of the first heat medium heat exchanger 11 and the upstream of the load devices 3A and 3B. The other end of the third heat medium piping 70 is connected to the first heat medium piping 40 between the downstream of the second heat medium heat exchanger 21 and the upstream of the first heat medium heat exchanger 11.

[0044] The third heat medium pipe 70 constituting the third heat medium circuit 7 is provided with a flow control device 7a that controls the flow rate of the heat medium passing through the load devices 3C and 3D. The number of flow control devices 7a corresponds to the number of load devices 3 provided in the third heat medium circuit 7, and two are provided here. The flow control device 7a is configured with an adjustable valve, such as a solenoid valve or an expansion valve driven by a stepping motor, for example. The opening of the flow control device 7a is controlled by a control device 101. Although not shown, the refrigeration cycle apparatus 100 may also have a flow control device that adjusts the flow rate of the heat medium passing through the load-side heat exchangers 30 of the load devices 3A and 3B.

[0045] The third heat medium circuit 7 is a circuit in which the first heat medium heat exchanger 11, the load side heat exchanger 30, and the flow rate control device 7a are connected in sequence by piping. In this example, the third heat medium circuit 7 has two load side heat exchangers 30, which are connected by piping so that the heat medium passes through them in parallel.

[0046] The third heat medium circuit 7 is connected in parallel to the repeater-routing circuit 8 of the first heat medium circuit 4. The repeater-routing circuit 8 is a circuit in the first heat medium circuit 4 that runs from point A in FIG. 1 through the repeater 2, passes through the flow path switching device 6a, the load-side heat exchanger 30, the flow path switching device 6b, and the second heat medium heat exchanger 21, and reaches point B. Point A is the inlet point of the heat medium to the repeater 2 in the first heat medium circuit 4. Point B is the outlet point of the heat medium from the repeater 2 in the first heat medium circuit 4. In this way, the third heat medium circuit 7 is connected in parallel to the repeater-routing circuit 8 and is a non-repeater-routing circuit that does not pass through the repeater 2.

[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 flow path switching devices 6a and 6b, but the 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 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, the third heat medium heat exchanger 22, and the second pump 51 are independent and housed in separate housings.

[0049] Furthermore, in the refrigeration cycle apparatus 100, the numbers of heat source units 1, relay units 2, and load devices 3 are not limited to the numbers shown in the figure. Two or more heat source units 1 may be installed. One load device 3 may be directly connected to the heat source unit 1, or three or more load devices 3 may be installed. Two or more relay units 2 may be installed. Three or more load devices 3 may be connected to each relay unit 2.

[0050] 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 100 include cooling operation, heating operation, cooling-dominated operation, and heating-dominated operation.

[0051] 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.

[0052] 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 3 are performing cooling and one load device 3 is performing heating, it is assumed that the cooling load is larger than the heating load.

[0053] Before describing each operation, we will explain how to read the figures common to FIGS. 2 to 7, which will be described later. In FIGS. 2 to 7, the black and white triangles of the symbols 6a and 6b indicate the switching states of the flow path switching devices 6a and 6b. In the symbols 6a and 6b, when the left triangle of the three triangles on the left, right, and bottom is black, the flow path switching devices 6a and 6b are switched to the first state and the load-side heat exchanger 30 is connected to the first heat medium circuit 4. In the symbols 6a and 6b, when the bottom triangle of the three triangles on the left, right, and bottom is black, the flow path switching devices 6a and 6b are switched to the second state and the load-side heat exchanger 30 is connected to the second heat medium circuit 5.

[0054] In the following description, the state in which the flow path switching devices 6a and 6b are switched to the first state and the load-side heat exchanger 30 is connected to the first heat medium circuit 4 will be expressed as "the flow path switching devices 6a and 6b are open to the first heat medium circuit 4 side." Furthermore, the state in which the flow path switching devices 6a and 6b are switched to the second state and the load-side heat exchanger 30 is connected to the second heat medium circuit 5 will be expressed as "the flow path switching devices 6a and 6b are open to the second heat medium circuit 5 side."

[0055] (Cooling Operation) First, the cooling operation of the refrigeration cycle apparatus 100 will be described with reference to Fig. 2. Fig. 2 is a refrigerant circuit diagram showing the flow of refrigerant and heat medium in the refrigeration cycle apparatus 100 according to the first embodiment when all the load devices 3 are performing cooling. Note that "when all the load devices 3 are performing cooling" means when all the load devices 3 in operation are performing cooling, and some of the load devices 3 may be stopped. Fig. 2 shows the flow of refrigerant and heat medium when the load device 3A is stopped, the load device 3B is performing cooling, the load device 3C is performing cooling, and the load device 3D is performing cooling.

[0056] In cooling operation, the refrigeration cycle apparatus 100 stops the second refrigerant circuit 20 and operates only the first refrigerant circuit 10 and the first heat medium circuit 4. In the operation example of Fig. 2, the refrigeration cycle apparatus 100 opens the flow switching devices 6a and 6b connected to the load device 3A to be stopped to the second heat medium circuit 5 side, and opens the flow switching devices 6a and 6b connected to the load device 3B performing cooling to the first heat medium circuit 4 side. The refrigeration cycle apparatus 100 also opens the flow control device 7a connected to the load devices 3C and 3D performing cooling. The opening degree of the flow control device 7a is adjusted by the control device 101 depending on the loads of the load devices 3C and 3D.

[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 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.

[0058] 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 cold water, and then flows to the load device 3B via the relay unit 2. A portion of the heat medium flowing through the first heat medium circuit 4 flows to the load devices 3C and 3D via the third heat medium circuit 7. The heat medium flowing through the load side heat exchangers 30 of the load devices 3B, 3C, and 3D is heated by heat exchange with the indoor air in the indoor space. The heat medium heated in the load side heat exchanger 30 of the load device 3B flows back into the first heat medium heat exchanger 11 via the relay unit 2. The heat medium heated in the load side heat exchangers 30 of the load devices 3C and 3D flows back into the first heat medium heat exchanger 11 without passing through the relay unit 2. In addition, when the load device 3A is stopped, the flow path switching devices 6a and 6b connected to the load device 3A are opened to the second heat medium circuit 5 side, and the second pump 51 is stopped due to the stop of the second refrigerant circuit 20, so that the heat medium does not circulate in the load side heat exchanger 30 of the load device 3A, and the load device 3A is in a stopped state.

[0059] (Heating Operation) Next, the heating operation of the refrigeration cycle apparatus 100 will be described with reference to Fig. 3. Fig. 3 is a refrigerant circuit diagram showing the flow of the refrigerant and heat medium in the refrigeration cycle apparatus 100 according to embodiment 1 when all of the load devices 3 perform heating. Note that "when all of the load devices 3 perform heating" means when all of the load devices 3 in operation perform heating, and some of the load devices 3 may be stopped. Fig. 3 shows the flow of the refrigerant and heat medium when the load device 3A is stopped, the load device 3B performs heating, the load device 3C performs heating, and the load device 3D performs heating.

[0060] In heating operation, the refrigeration cycle apparatus 100 stops the second refrigerant circuit 20 and operates only the first refrigerant circuit 10 and the first heat medium circuit 4. In the operation example of Fig. 3, the refrigeration cycle apparatus 100 opens the flow switching devices 6a and 6b connected to the load device 3B that performs heating to the first heat medium circuit 4 side, and opens the flow switching devices 6a and 6b connected to the load device 3A that is stopped to the second heat medium circuit 5 side. The refrigeration cycle apparatus 100 also opens the flow control device 7a connected to the load devices 3C and 3D that perform heating. The opening degree of the flow control device 7a is adjusted by the control device 101 depending on the loads on the load devices 3C and 3D.

[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 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, and is then decompressed by the first expansion mechanism 15 to become a low-pressure gas-liquid two-phase refrigerant and flows into 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.

[0062] 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 to the load device 3B via the relay unit 2. The heat medium flowing through the first heat medium circuit 4 also flows to the load devices 3C and 3D without passing through the relay unit 2. The heat medium flowing through the load side heat exchangers 30 of the load devices 3B, 3C, and 3D exchanges heat with the indoor air in the indoor space and is cooled. The heat medium cooled in the load side heat exchanger 30 of the load device 3B flows back into the first heat medium heat exchanger 11 via the relay unit 2. The heat medium cooled in the load side heat exchangers 30 of the load devices 3C and 3D also flows back into the first heat medium heat exchanger 11 without passing through the relay unit 2. In addition, when the load device 3A is stopped, the flow path switching devices 6a and 6b connected to the load device 3A are opened to the second heat medium circuit 5 side, and the second pump 51 is stopped due to the stop of the second refrigerant circuit 20, so that the heat medium does not circulate in the load side heat exchanger 30 of the load device 3A, and the load device 3A is in a stopped state.

[0063] (Cooling-dominated operation) Next, referring to Fig. 4, a case where cooling is performed by some of the load devices 3 and heating is performed by the remaining load devices 3, and cooling-dominated operation with a large cooling load is described. Fig. 4 is a refrigerant circuit diagram showing the flow of refrigerant and heat medium in the refrigeration cycle device 100 according to embodiment 1 when cooling is the dominant operation. Fig. 4 shows the flow of refrigerant and heat medium when load device 3A performs cooling, load device 3B performs heating, load device 3C performs cooling, and load device 3D performs cooling.

[0064] In cooling-dominated operation, the refrigeration cycle apparatus 100 operates the first refrigerant circuit 10, the first heat medium circuit 4, the second refrigerant circuit 20, and the second heat medium circuit 5. In the operation example of Fig. 4, the refrigeration cycle apparatus 100 opens the flow switching devices 6a and 6b connected to the load device 3A that performs cooling to the first heat medium circuit 4 side. The refrigeration cycle apparatus 100 opens the flow switching devices 6a and 6b connected to the load device 3B that performs heating to the second heat medium circuit 5 side. The refrigeration cycle apparatus 100 also opens the flow control device 7a connected to the load devices 3C and 3D that perform cooling. The opening degree of the flow control device 7a is adjusted by the control device 101 depending on the loads of the load devices 3C and 3D.

[0065] 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.

[0066] 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. The chilled water from the first heat medium circuit 4 flows to the load device 3 that performs cooling. Specifically, of the load devices 3A, 3C, and 3D that perform cooling, the chilled water from the first heat medium circuit 4 flows into the load device 3A via the relay unit 2, and into the load devices 3C and 3D via the third heat medium circuit 7 without passing through the relay unit 2. The chilled water that flows into the load side heat exchanger 30 of the load device 3A exchanges heat with the indoor air in the indoor space and is heated. The heated heat medium flows through the relay unit 2 and then flows back into the first heat medium heat exchanger 11. The chilled water that flows into the load side heat exchangers 30 of the load devices 3C and 3D exchanges heat with the indoor air in the indoor space and is heated. The heated heat medium flows back into the first heat medium heat exchanger 11.

[0067] In the second refrigerant circuit 20, high-temperature, high-pressure gas refrigerant discharged from the second compressor 23 passes through the second flow switching valve 24 and flows to the third heat medium heat exchanger 22, where it condenses and liquefies through heat exchange with the heat medium flowing in the second heat medium circuit 5. The condensed and liquefied refrigerant is decompressed by the second expansion mechanism 25 to become a low-pressure gas-liquid two-phase refrigerant, and flows to the second heat medium heat exchanger 21, where it exchanges heat with the heat medium flowing in the first heat medium circuit 4 and evaporates into gas. The gasified refrigerant passes through the second flow switching valve 24 and is drawn into the second compressor 23 via an accumulator.

[0068] On the other hand, the heat medium flowing through the second heat medium circuit 5 is heated by the refrigerant flowing through the third heat medium heat exchanger 22 to become hot water, and then flows to the load-side heat exchanger 30 of the load device 3B that performs heating, where it is cooled by heat exchange with the indoor air in the indoor space. The cooled heat medium flows into the third heat medium heat exchanger 22 again.

[0069] In this way, in cooling-dominated operation, load devices 3A and 3B connected to heat source unit 1 via relay unit 2 perform simultaneous cooling and heating operation, while load devices 3C and 3D connected to heat source unit 1 without going through relay unit 2 perform uniform cooling operation.

[0070] (Heating-dominated operation) Next, with reference to Fig. 5 , a case where some of the load devices 3 perform cooling and the remaining load devices 3 perform heating, and where heating-dominated operation is performed with a large heating load, will be described. Fig. 5 is a refrigerant circuit diagram showing the flow of refrigerant and heat medium in the refrigeration cycle device 100 according to embodiment 1 when heating-dominated operation is performed. Fig. 5 shows the flow of refrigerant and heat medium when load device 3A performs cooling, load device 3B performs heating, load device 3C performs heating, and load device 3D performs heating.

[0071] In the heating-dominated operation, the refrigeration cycle apparatus 100 operates the first refrigerant circuit 10, the first heat medium circuit 4, the second refrigerant circuit 20, and the second heat medium circuit 5. In the operation example of Fig. 5, the refrigeration cycle apparatus 100 opens the flow switching devices 6a and 6b connected to the load device 3B that performs heating to the first heat medium circuit 4 side. The refrigeration cycle apparatus 100 opens the flow switching devices 6a and 6b connected to the load device 3A that performs cooling to the second heat medium circuit 5 side. The refrigeration cycle apparatus 100 also opens the flow control device 7a connected to the load devices 3C and 3D that perform heating. The opening degree of the flow control device 7a is adjusted by the control device 101 depending on the loads of the load devices 3C and 3D.

[0072] 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, and is then decompressed by the first expansion mechanism 15 to become a low-pressure gas-liquid two-phase refrigerant and flows into 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.

[0073] 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 and becomes hot water. The hot water in the first heat medium circuit 4 flows to the load device 3 that performs heating. Specifically, of the load devices 3B, 3C, and 3D that perform heating, the hot water in the first heat medium circuit 4 flows into the load device 3B via the relay unit 2, and into the load devices 3C and 3D via the third heat medium circuit 7 without passing through the relay unit 2. The hot water that flows into the load side heat exchanger 30 of the load device 3B exchanges heat with the indoor air in the indoor space and is cooled. The cooled heat medium flows through the relay unit 2 and then flows back into the first heat medium heat exchanger 11. The hot water that flows into the load side heat exchangers 30 of the load devices 3C and 3D exchanges heat with the indoor air in the indoor space and is cooled. The cooled heat medium flows back into the first heat medium heat exchanger 11.

[0074] In the second refrigerant circuit 20, high-temperature, high-pressure gas refrigerant discharged from the second compressor 23 passes through the second flow switching valve 24 and flows to the second heat medium heat exchanger 21, where it condenses and liquefies through heat exchange with the heat medium flowing in the first heat medium circuit 4. The condensed and liquefied refrigerant is decompressed by the second expansion mechanism 25 to become a low-pressure gas-liquid two-phase refrigerant, and flows to the third heat medium heat exchanger 22, where it exchanges heat with the heat medium flowing in the second heat medium circuit 5 and evaporates into gas. The gasified refrigerant passes through the second flow switching valve 24 and is drawn into the second compressor 23 via an accumulator.

[0075] On the other hand, the heat medium flowing through the second heat medium circuit 5 is cooled by the refrigerant flowing through the third heat medium heat exchanger 22 to become cold water, and then flows to the load-side heat exchanger 30 of the load device 3A that performs cooling, where it is heated by heat exchange with the indoor air in the indoor space. The heated heat medium flows into the third heat medium heat exchanger 22 again.

[0076] In this way, in heating-dominated operation, load devices 3A and 3B connected to heat source unit 1 via relay unit 2 perform simultaneous heating and cooling operation, while load devices 3C and 3D connected to heat source unit 1 without going through relay unit 2 perform uniform heating operation.

[0077] (Simultaneous operation of cooling and hot water supply) Figure 6 is a refrigerant circuit diagram showing Modification 1 of the refrigeration cycle apparatus 100 according to Embodiment 1, illustrating simultaneous operation of cooling and hot water supply. The refrigeration cycle apparatus 100 of Modification 1 is the same as the refrigeration cycle apparatus 100 of Figure 1 except that the load device 3B is a hot water supply device that supplies hot water. The refrigeration cycle apparatus 100 of Modification 1 has a configuration in which indoor units and hot water supply devices are mixed in multiple load devices 3. Figure 6 shows the flow of refrigerant and heat medium when load device 3A performs cooling, load device 3B performs hot water supply, load device 3C performs cooling, and load device 3D performs cooling.

[0078] The load device 3B has a load-side heat exchanger 91, a hot water storage tank 92, and a hot water pump 93. The load-side heat exchanger 91, the hot water storage tank 92, and the hot water pump 93 are connected by a water pipe 90 to form a hot water circuit 9 through which water circulates. The load-side heat exchanger 91 is a heat exchanger that exchanges heat between the heat medium circulating through the second heat medium circuit 5 and the water circulating through the hot water circuit 9. The hot water pump 93 draws water in the hot water circuit 9, applies pressure, and sends it out to circulate. The load device 3B, which is a hot water supply device, heats the water circulating through the hot water circuit 9 and the heat medium circulating through the second heat medium circuit 5 in the load-side heat exchanger 91, and stores the heated hot water in the hot water storage tank 92.

[0079] In Fig. 6, the flow of the refrigerant and the heat medium is the same as in the cooling-dominated operation shown in Fig. 4, and therefore description thereof will be omitted. In the refrigeration cycle device 100, hot water circulating through the second heat medium circuit 5 and water circulating through the hot water circuit 9 by the hot water supply pump 93 are heated by heat exchange in the load-side heat exchanger 91, and the heated hot water is stored in the hot water storage tank 92.

[0080] In this way, in simultaneous operation of air conditioning and hot water supply, load devices 3A and 3B connected to heat source unit 1 via relay unit 2 operate in simultaneous air conditioning and hot water supply, while load devices 3C and 3D connected to heat source unit 1 without going through relay unit 2 operate in a unified air conditioning mode.

[0081] (Simultaneous operation of heating and hot water supply) Fig. 7 is a refrigerant circuit diagram showing Modification 1 of the refrigeration cycle apparatus 100 according to Embodiment 1, in which heating and hot water supply are simultaneously performed. The configuration of the refrigeration cycle apparatus 100 is the same as that shown in Fig. 6. Fig. 7 shows the flow of the refrigerant and heat medium when load device 3A performs heating, load device 3B performs hot water supply, load device 3C performs heating, and load device 3D performs heating.

[0082] In the simultaneous heating and hot water supply operation, the refrigeration cycle apparatus 100 operates the first refrigerant circuit 10, the first heat medium circuit 4, the second refrigerant circuit 20, the second heat medium circuit 5, and the hot water supply circuit 9. In the operation example of Fig. 7 , the refrigeration cycle apparatus 100 opens the flow path switching devices 6a and 6b connected to the load device 3A that performs heating to the first heat medium circuit 4 side. The refrigeration cycle apparatus 100 opens the flow path switching devices 6a and 6b connected to the load device 3B that performs hot water supply to the second heat medium circuit 5 side. The refrigeration cycle apparatus 100 also opens the flow control device 7a connected to the load devices 3C and 3D that perform heating. The opening degree of the flow control device 7a is adjusted by the control device 101 according to the loads of the load devices 3C and 3D.

[0083] The operation of the first refrigerant circuit 10 is the same as in the heating-dominant operation, and therefore a description thereof will be omitted. 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. The hot water from the first heat medium circuit 4 flows to the load devices 3 that perform heating. Specifically, of the load devices 3A, 3C, and 3D that perform heating, the hot water from the first heat medium circuit 4 flows into the load device 3A via the relay unit 2, and into the load devices 3C and 3D via the third heat medium circuit 7 without passing through the relay unit 2. The hot water that flows into the load-side heat exchanger 30 of the load device 3A exchanges heat with the indoor air in the indoor space and is cooled. The cooled heat medium flows through the relay unit 2 and then flows back into the first heat medium heat exchanger 11. The hot water that flows into the load-side heat exchangers 30 of the load devices 3C and 3D exchanges heat with the indoor air in the indoor space and is cooled. The cooled heat medium flows into the first heat medium heat exchanger 11 again.

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

[0085] On the other hand, the heat medium flowing through the second heat medium circuit 5 is heated by the refrigerant flowing through the third heat medium heat exchanger 22 to become hot water for hot water supply, and then flows to the load-side heat exchanger 91 of the load device 3B, which is a hot water supply device, and is cooled by heat exchange with water circulating through the hot water supply circuit 9. The cooled heat medium flows into the third heat medium heat exchanger 22 again.

[0086] The water circulating through the hot water supply circuit 9 is heated by the refrigerant flowing through the load-side heat exchanger 91 to become hot water, and then stored in the hot water storage tank 92 .

[0087] In this way, in simultaneous operation of heating and hot water supply, load devices 3A and 3B connected to heat source unit 1 via relay unit 2 operate in simultaneous heating and hot water supply, while load devices 3C and 3D connected to heat source unit 1 without going through relay unit 2 operate in a unified heating operation.

[0088] Note that some or all of the load devices 3 connected to the relay unit 2 may be hot water supply devices as shown in the figure. In this case, the second flow path switching valve 24 may be omitted from the second refrigerant circuit 20.

[0089] As described above, the refrigeration cycle apparatus 100 according to the first embodiment includes the heat source apparatus 1, the relay apparatus 2 connected to the heat source apparatus 1, and three or more load devices 3. The heat source apparatus 1 includes a first refrigerant circuit 10 through which a refrigerant circulates and a first heat medium heat exchanger 11 that exchanges heat with the first refrigerant circuit 10. The relay apparatus 2 includes a second refrigerant circuit 20 through which a refrigerant circulates, a second heat medium heat exchanger 21 that exchanges heat with the second refrigerant circuit 20, and a third heat medium heat exchanger 22 that exchanges heat with the second refrigerant circuit 20. In the refrigeration cycle apparatus 100, the first heat medium heat exchanger 11, the second heat medium heat exchanger 21, and at least two or more of the three or more load devices 3 are connected by the first heat medium piping 40 to form a first heat medium circuit 4 through which a heat medium circulates. In the refrigeration cycle apparatus 100, the third heat medium heat exchanger 22 and at least two or more load devices 3 are connected by second heat medium piping 50 to form a second heat medium circuit 5 through which the heat medium circulates. In the refrigeration cycle apparatus 100, a third heat medium circuit 7 is formed in which the heat medium circulates between the first heat medium heat exchanger 11 and other load devices 3 of the three or more load devices 3 without passing through the relay unit 2. In the example of Fig. 1 , the "three or more load devices 3" are load devices 3A, 3B, 3C, and 3D, the "at least two or more load devices 3" are load devices 3A and 3B, and the "other load devices 3" are load devices 3C and 3D.

[0090] As described above, the refrigeration cycle apparatus 100 is an apparatus capable of simultaneous cooling and heating operation, including a heat source apparatus 1, a relay apparatus 2, and three or more load apparatuses 3. The refrigeration cycle apparatus 100 has load apparatuses 3A and 3B connected directly to the heat source apparatus 1 without going through the relay apparatus 2. The refrigeration cycle apparatus 100 is configured so that load apparatuses 3C and 3D, which do not require simultaneous cooling and heating operation, are directly connected to the heat source apparatus 1 without going through the relay apparatus 2, thereby simplifying the overall configuration of the refrigeration cycle apparatus compared to a configuration that goes through the relay apparatus 2. If the load apparatuses 3C and 3D were configured to go through the relay apparatus 2, it would be necessary to provide two relay apparatuses 2, one for the load apparatuses 3A and 3B and one for the load apparatuses 3C and 3D, complicating the configuration. The refrigeration cycle apparatus 100 is configured so that load apparatuses 3C and 3D, which do not require simultaneous cooling and heating operation, are directly connected to the heat source apparatus 1 without going through the relay apparatus 2, thereby avoiding such a complicated configuration. As described above, the refrigeration cycle apparatus 100 can achieve simultaneous heating and cooling operations while reducing costs.

[0091] Furthermore, in the refrigeration cycle apparatus 100, when cooling and heating are performed simultaneously in the load devices 3A and 3B connected to the relay unit 2 among the three or more load devices 3, the first refrigerant circuit 10 provided in the heat source unit 1 and the second refrigerant circuit 20 provided in the relay unit 2 can perform cooling or heating, respectively. Therefore, the refrigeration cycle apparatus 100 can reduce the number of pipes connecting the heat source unit 1 and the relay unit 2 to two, which reduces the number of pipes required and reduces the burden of piping construction.

[0092] The third heat medium circuit 7 has a third heat medium piping 70 that passes a heat medium through the load devices 3C and 3D. One end of the third heat medium piping 70 is connected to the first heat medium piping 40 between the downstream of the first heat medium heat exchanger 11 and the upstream of the load devices 3A and 3B. The other end of the third heat medium piping 70 is connected to the first heat medium piping 40 between the downstream of the second heat medium heat exchanger 21 and the upstream of the first heat medium heat exchanger 11.

[0093] In this way, the refrigeration cycle apparatus 100 can be configured such that the third heat medium circuit 7 has the third heat medium pipe 70, and the load devices 3C and 3D are directly connected to the relay unit 2.

[0094] The third heat medium circuit 7 is provided with a flow rate control device 7a that controls the flow rate of the heat medium flowing into the load devices 3C and 3D.

[0095] In this way, the refrigeration cycle device 100 of this embodiment 1 has a flow control device 7a, so that the flow rate of the heat medium flowing to the load devices 3C and 3D can be controlled according to the operating state of the load devices 3C and 3D, and the capacity can be adjusted.

[0096] Second Embodiment Next, a refrigeration cycle apparatus 100 according to a second embodiment will be described with reference to Fig. 8. Fig. 8 is a refrigerant circuit diagram of the refrigeration cycle apparatus 100 according to the second embodiment. Note that the same components as those in the refrigeration cycle apparatus 100 described in the first embodiment are denoted by the same reference numerals, and the description thereof will be omitted as appropriate.

[0097] The refrigeration cycle apparatus 100 of the second embodiment further includes a bypass pipe 60 and a bypass valve 61 in addition to the components of the refrigeration cycle apparatus 100 of the first embodiment shown in Fig. 1 . The bypass pipe 60 and the bypass valve 61 are provided in the relay unit 2. The bypass pipe 60 is a pipe that merges a portion of the heat medium supplied from the heat source unit 1 to the relay unit 2 in the first heat medium circuit 4 with the heat medium flowing from the load unit 3 to the second heat medium heat exchanger 21 in the first heat medium circuit 4. The upstream end of the bypass pipe 60 is connected to the first heat medium pipe 40 between the downstream of the first heat medium heat exchanger 11 and the upstream of the load side heat exchanger 30 in the first heat medium circuit 4. The downstream end of the bypass pipe 60 is connected to the first heat medium pipe 40 between the downstream of the load side heat exchanger 30 and the upstream of the second heat medium heat exchanger 21 in the first heat medium circuit 4.

[0098] The bypass valve 61 adjusts the flow rate of the heat medium flowing through the bypass pipe 60. The bypass valve 61 is, for example, a two-way valve, and its opening and closing are controlled by the control device 101. The bypass valve 61 may also be a two-way valve whose valve opening (opening area) can be controlled. The bypass valve 61 is closed during cooling operation and heating operation, and is opened during mixed operation in specific cases described below. Mixed operation is an operation in which, among the multiple load devices 3A, 3B, 3C, and 3D, load devices 3A and 3B connected to the relay unit 2 are connected to a first heat medium circuit 4 and a second heat medium circuit 5. Mixed operation includes cooling-dominated operation, heating-dominated operation, simultaneous cooling and hot water supply operation, and simultaneous heating and hot water supply operation.

[0099] In mixed operation, if the main load, which is the load of the load device 3 connected to the first heat medium circuit 4 among the load devices 3 connected to the relay unit 2, and the secondary load, which is the load of the load device 3 connected to the second heat medium circuit 5 among the load devices 3 connected to the relay unit 2, are in the "main load < secondary load" state, the following problem occurs.

[0100] This problem will be explained in the case where the mixed operation is cooling-dominated operation. In cooling-dominated operation, the main load is a cooling load and the secondary load is a heating load. In the refrigeration cycle apparatus 100, when the "main load < secondary load" during mixed operation, if the bypass piping 60 is not provided, the refrigerant in the second refrigerant circuit 20 cannot sufficiently absorb heat from the heat medium in the second heat medium heat exchanger 21. As a result, the refrigeration cycle apparatus 100 cannot ensure sufficient capacity to process the heating load, which is the secondary load. Specifically, in the example of FIG. 4 , when the cooling load of the load device 3A that performs cooling and the heating load of the load device 3B that performs heating are smaller than the cooling load, the refrigeration cycle apparatus 100 cannot ensure sufficient capacity to process the heating load.

[0101] In the refrigeration cycle apparatus 100, there is a restriction on the temperature of the heat medium, and the temperature of the heat medium needs to be above 0°C to prevent freezing. In cooling-dominated operation, the temperature of the heat medium in the first heat medium circuit 4 that passes from the load device 3 through the second heat medium heat exchanger 21 and returns to the heat source unit 1 needs to be above 0°C. Because of this restriction, if the refrigeration cycle apparatus 100 does not have the bypass piping 60, when the load of the load device 3 connected to the relay unit 2 is "primary load < secondary load," the refrigerant in the second refrigerant circuit 20 cannot absorb a sufficient amount of heat from the heat medium in the second heat medium heat exchanger 21.

[0102] The refrigeration cycle apparatus 100 of the second embodiment has a bypass pipe 60, and part of the heat medium flowing from the heat source unit 1 to the relay unit 2 in the first heat medium circuit 4 is merged with the heat medium flowing from the load device 3 to the second heat medium heat exchanger 21 in the first heat medium circuit 4. This allows the refrigeration cycle apparatus 100 to increase the flow rate of the heat medium flowing into the second heat medium heat exchanger 21, and increase the amount of heat absorbed by the refrigerant in the second refrigerant circuit 20 from the heat medium. As a result, the refrigeration cycle apparatus 100 can ensure sufficient capacity to process the heating load, which is a secondary load.

[0103] Next, a case where the mixed operation is heating-dominated operation will be described. In the refrigeration cycle apparatus 100, there are restrictions on the temperature of the equipment used, and the temperature of the heat medium must be below the heat resistance temperature of the equipment (e.g., 50°C). In heating-dominated operation, if the load of the load device 3 connected to the relay unit 2 is "primary load < secondary load," that is, if the heating load < cooling load, if the bypass piping 60 is not provided, the refrigerant in the second refrigerant circuit 20 cannot sufficiently dissipate heat to the heat medium in the second heat medium heat exchanger 21.

[0104] The refrigeration cycle apparatus 100 of the second embodiment has a bypass pipe 60, and part of the heat medium flowing from the heat source unit 1 to the relay unit 2 in the first heat medium circuit 4 is merged with the heat medium flowing from the load device 3 to the second heat medium heat exchanger 21 in the first heat medium circuit 4. This allows the refrigeration cycle apparatus 100 to increase the flow rate of the heat medium flowing into the second heat medium heat exchanger 21, and increase the amount of heat released by the refrigerant in the second heat medium heat exchanger 21 to the heat medium. As a result, the refrigeration cycle apparatus 100 can ensure sufficient capacity to process the cooling load, which is the secondary load.

[0105] In cooling-dominant operation and heating-dominant operation, the refrigeration cycle apparatus 100 opens the bypass valve 61 when the load on the load device 3 connected to the relay unit 2 is "main load < secondary load." This allows the refrigeration cycle apparatus 100 to ensure sufficient capacity to process the secondary load. Note that in cooling-dominant operation and heating-dominant operation, the refrigeration cycle apparatus 100 closes the bypass valve 61 when the load on the load device 3 connected to the relay unit 2 is "main load > secondary load." Similarly, in simultaneous cooling and hot water supply operation and simultaneous heating and hot water supply operation, the refrigeration cycle apparatus 100 opens the bypass valve 61 when "main load < secondary load" and closes the bypass valve 61 when "main load > secondary load." The bypass valve 61 is not limited to being opened or closed, and its opening degree may be adjusted, for example, according to the difference between the main load and the secondary load.

[0106] The refrigeration cycle device 100 of the second embodiment can obtain the same effects as those of the first embodiment, and by having the bypass piping 60 and the bypass valve 61, it can ensure sufficient capacity to process the secondary load when the "primary load < secondary load" during mixed operation.

[0107] 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.

[0108] 1 Heat source unit, 2 Relay unit, 3 Load device, 3A Load device, 3B Load device, 3C Load device, 3D Load device, 4 First heat medium circuit, 5 Second heat medium circuit, 6 Flow path switching device, 6a Flow path switching device, 6b Flow path switching device, 7 Third heat medium circuit, 7a Flow control device, 8 Relay unit via circuit, 9 Hot water supply circuit, 10 First refrigerant circuit, 11 First heat medium heat exchanger, 12 First compressor, 13 First flow path switching valve, 14 Heat source side heat exchanger, 15 First expansion mechanism, 16 Heat source side blower, 20 Second refrigerant circuit, 21 Second heat medium heat exchanger, 22 Third heat medium heat exchanger, 23 Second compressor, 24 Second flow path switching valve, 25 Second expansion mechanism, 30 Load side heat exchanger, 31 Load side blower, 40 First heat medium piping, 41 First pump, 50 Second heat medium piping, 51 Second pump, 60 Bypass piping, 61 Bypass valve, 70 Third heat medium piping, 90 Water piping, 91 Load side heat exchanger, 92 Hot water storage tank, 93 Hot water pump, 100 Refrigeration cycle device, 101 Control device, A Inlet portion, B Outlet portion.

Claims

1. A refrigeration cycle system comprising a heat source unit, a relay unit connected to the heat source unit, and three or more load devices, The heat source unit includes a first refrigerant circuit through which a refrigerant circulates, and the first refrigerant circuit includes a first heat transfer medium heat exchanger that exchanges heat between the refrigerant flowing through the first refrigerant circuit and a heat transfer medium flowing inside it. The relay unit includes a second refrigerant circuit through which a refrigerant circulates, and the second refrigerant circuit includes a second heat exchanger that exchanges heat between the refrigerant flowing through the second refrigerant circuit and a heat transfer medium flowing inside, and a third heat exchanger that exchanges heat between the refrigerant flowing through the second refrigerant circuit and a heat transfer medium flowing inside. The first heat transfer medium heat exchanger, the second heat transfer medium heat exchanger, and at least two of the three or more load devices are connected by a first heat transfer medium piping, forming a first heat transfer medium circuit through which the heat transfer medium circulates. The third heat transfer fluid heat exchanger and the at least two load devices are connected by a second heat transfer fluid piping, and a second heat transfer fluid circuit is formed through which the heat transfer fluid circulates. A refrigeration cycle apparatus is formed in which a third heat transfer medium circuit is formed, through which the heat transfer medium circulates between the first heat transfer medium heat exchanger and the other load devices among the three or more load devices, without passing through the aforementioned relay device.

2. The third heat transfer circuit has a third heat transfer pipe that passes the heat transfer medium to the other load device, The refrigeration cycle apparatus according to claim 1, wherein one end of the third heat transfer piping is connected in the first heat transfer piping between the downstream of the first heat transfer heat exchanger and the upstream of the at least two load devices, and the other end is connected in the first heat transfer piping between the downstream of the second heat transfer heat exchanger and the upstream of the first heat transfer heat exchanger.

3. The refrigeration cycle apparatus according to claim 1 or 2, wherein the third heat transfer medium circuit is provided with a flow control device for controlling the flow rate of the heat transfer medium passing through the other load device.

4. A bypass pipe in the first heat transfer medium circuit that connects a portion of the heat transfer medium supplied from the heat source to the relay to the heat transfer medium going from the at least two load devices to the second heat transfer medium heat exchanger in the first heat transfer medium circuit, A refrigeration cycle apparatus according to claim 1 or claim 2, further comprising a bypass valve for adjusting the flow rate of a heat transfer medium flowing through the bypass piping.

5. The system includes a flow path switching device provided in the first heat transfer fluid circuit and the second heat transfer fluid circuit, The flow path of the heat transfer medium passing through each of the at least two load devices is connected to the first heat transfer medium circuit or the second heat transfer medium circuit by the flow path switching device. The aforementioned bypass valve is In mixed operation in which at least two or more load devices are connected to the first heat transfer fluid circuit and load devices are connected to the second heat transfer fluid circuit, The refrigeration cycle apparatus according to claim 4, wherein a main load, which is the load of a load device connected to the first heat transfer medium circuit, and a secondary load, which is the load of a load device connected to the second heat transfer medium circuit, are opened when the main load < the secondary load, and closed when the main load > the secondary load.

6. The refrigeration cycle apparatus according to claim 1 or claim 2, wherein at least one of the three or more load devices is an indoor unit having a load-side heat exchanger.

7. The refrigeration cycle apparatus according to claim 6, wherein at least one of the three or more load devices is a hot water supply device having a hot water storage tank.