EP4653780A1

EP4653780A1 - Refrigeration cycle device

Info

Publication number: EP4653780A1
Application number: EP23917537.5A
Authority: EP
Inventors: Kosuke Miyawaki; Yuki Mizuno; Jun Nishio; Hirokuni Shiba; Takashi Okazaki; Hiroaki Asanuma; Kosuke Kawano
Original assignee: Mitsubishi Electric Corp
Current assignee: Mitsubishi Electric Corp
Priority date: 2023-01-20
Filing date: 2023-01-20
Publication date: 2025-11-26
Also published as: EP4653780A4; JP7378685B1; WO2024154324A1; JPWO2024154324A1

Abstract

A refrigeration cycle apparatus according to the present disclosure includes a heat medium circuit in which a heat medium circulates. The heat medium circuit includes a plurality of load-side heat exchangers that cause heat exchange to be performed between first refrigerant and the heat medium, a plurality of use-side heat exchangers into which the heat medium supplied from at least one of the load-side heat exchangers flows, and a pump. In the heat medium circuit, the heat medium is supplied to a first load-side heat exchanger and a second load-side heat exchanger by the one pump, where the first load-side heat exchanger is one of the load-side heat exchangers, and the second load-side heat exchanger is one of those of the load-side heat exchangers that supply the heat medium having a temperature different from a temperature of the heat medium that is supplied by the first load-side heat exchanger.

Description

Technical Field

The present disclosure relates to a refrigeration cycle apparatus.

Background Art

In existing refrigeration cycle apparatuses, a plurality of load-side heat exchangers are provided, and configured to cause heat exchange to be performed between first refrigerant and a heat medium different from the first refrigerant. In addition, of such existing refrigeration cycle apparatuses, a refrigeration cycle apparatus has been proposed that includes at least two load-side heat exchangers configured to supply heat media that have different temperatures and can flow into respective use-side heat exchangers (see, for example, Patent Literature 1). In the case where the refrigeration cycle apparatus is used as an air-conditioning apparatus, the use-side heat exchangers are heat exchangers configured to cool or heat an indoor space. Hereinafter, one of the plurality of load-side heat exchangers configured to supply heat media having different temperatures will be referred to as a first load-side heat exchanger. Furthermore, of the plurality of load-side heat exchangers configured to supply heat media having different temperatures, one of load-side heat exchangers configured to supply a heat medium having a temperature different from that of a heat medium to be supplied by the first load-side heat exchanger will be referred to as a second load-side heat exchanger.

Citation List

Patent Literature

Patent Literature 1: International Publication No. 2011/080802

Summary of Invention

Technical Problem

In the existing refrigeration cycle apparatus including the at least two load-side heat exchangers configured to supply heat media that have different temperatures and can flow into the respective use-side heat exchangers, a heat medium circuit in which a heat medium circulates includes: a pump configured to supply the heat medium to the first load-side heat exchanger; and a pump configured to supply the heat medium to the second load-side heat exchanger. In other words, the heat medium circuit of the existing refrigeration cycle apparatus needs to supply the heat media to the first load-side heat exchanger and the second load-side heat exchanger, using by the respective pumps. It should be noted that the pumps configured to supply a heat medium to the load-side heat exchangers are expensive. In addition, as the number of pumps configured to supply a heat medium to the load-side heat exchangers increases, the probability of occurrence of a pump failure also increases. Thus, in the existing refrigeration cycle apparatus including the at least two load-side heat exchangers configured to supply heat media that have different temperatures and can flow into the respective use-side heat exchangers, the manufacturing cost increases and the reliability decreases.
The present disclosure is applied to solve such problems as described above, and relates to a refrigeration cycle apparatus that includes at least two load-side heat exchangers configured to supply heat media having different temperatures, in which the heat media having different temperatures can flow into respective use-side heat exchangers, and that can be manufactured at a lower cost and be improved in reliability, as compared with existing refrigeration cycle apparatuses.

Solution to Problem

A refrigeration cycle apparatus according to an embodiment of the present disclosure includes: a heat medium circuit including a plurality of load-side heat exchangers and a plurality of use-side heat exchangers, the plurality of load-side heat exchangers being configured to cause heat exchange to be performed between first refrigerant and a heat medium different from the first refrigerant, the plurality of use-side heat exchangers being supplied with the heat medium supplied from at least one of the load-side heat exchangers, the heat medium circuit being a circuit in which the heat medium circulates. The heat medium circuit further includes: a joining portion configured to cause the heat medium that flows out from a first use-side heat exchanger and the heat medium that flows out from a second use-side heat exchanger to join together; a branching portion configured to cause a first heat medium pipe through which the heat medium that flows out from the joining portion flows to branch into a second heat medium pipe that is connected with a first load-side heat exchanger and a third heat medium pipe that is connected with a second load-side heat exchanger, the branching portion connecting the first load-side heat exchanger and the second load-side heat exchanger in parallel; and a pump provided between the joining portion and the branching portion and configured to circulate the heat medium, where the first load-side heat exchanger is one of the load-side heat exchangers, the first use-side heat exchanger is one of the use-side heat exchangers, into which the heat medium supplied from the first load-side heat exchanger flows, the second load-side heat exchanger is one of those of the load-side heat exchangers that are configured to supply the heat medium having a temperature different from a temperature of the heat medium that is supplied by the first load-side heat exchanger, and the second use-side heat exchanger is one of those of the use-side heat exchangers, into which the heat medium supplied from the second load-side heat exchanger flows, the one of the use-side heat exchangers being other than the first use-side heat exchanger.

Advantageous Effects of Invention

The heat medium circuit of the refrigeration cycle apparatus according to the embodiment of the present disclosure is capable of supplying the heat medium, by using the one pump, to the first load-side heat exchanger and the second load-side heat exchanger. Thus, in the refrigeration cycle apparatus according to the embodiment of the present disclosure, it is possible to reduce the number of pumps included in the heat medium circuit, as compared with existing refrigeration cycle apparatuses.
Accordingly, in the refrigeration cycle apparatus according to the embodiment of the present disclosure, it is possible to reduce the manufacturing cost and improve the reliability, as compared with the existing refrigeration cycle apparatuses.

Brief Description of Drawings

[Fig. 1] Fig. 1 is a refrigerant circuit diagram illustrating a refrigeration cycle apparatus according to Embodiment 1.
[Fig. 2] Fig. 2 is a refrigerant circuit diagram illustrating a modification of the refrigeration cycle apparatus according to Embodiment 1.
[Fig. 3] Fig. 3 is a refrigerant circuit diagram illustrating an example of a refrigeration cycle apparatus according to Embodiment 2.
[Fig. 4] Fig. 4 is a refrigerant circuit diagram illustrating another example of the refrigeration cycle apparatus according to Embodiment 2.
[Fig. 5] Fig. 5 is a refrigerant circuit diagram illustrating still another example of the refrigeration cycle apparatus according to Embodiment 2.
Figs. 7 to 10 are refrigerant circuit diagrams illustrating examples of a refrigeration cycle apparatus according to Embodiment 4.
[Fig. 6] Fig. 6 is a refrigerant circuit diagram illustrating a refrigeration cycle apparatus according to Embodiment 3.
[Fig. 7] Fig. 7 is a refrigerant circuit diagram illustrating an example of a refrigeration cycle apparatus according to Embodiment 4.
[Fig. 8] Fig. 8 is a refrigerant circuit diagram illustrating another example of the refrigeration cycle apparatus according to Embodiment 4.
[Fig. 9] Fig. 9 is a refrigerant circuit diagram illustrating still another example of the refrigeration cycle apparatus according to Embodiment 4.
[Fig. 10] Fig. 10 is a refrigerant circuit diagram illustrating a further example of the refrigeration cycle apparatus according to Embodiment 4.

Description of Embodiments

Examples of refrigeration cycle apparatuses according to the embodiments of the present disclosure will be described below with reference to, for example, drawings. It should be noted that in each of figures including Fig. 1 that will be referred to below, components that are the same as or equivalent to those in a previous figure or previous figures are denoted by the same reference signs. The same is true of the entire text of descriptions concerning the embodiments. In addition, in the descriptions concerning the embodiments, terms indicating directions may be used as appropriate in order that the examples of the refrigeration cycle apparatuses according to the embodiments of the present disclosure be easily understood. However, the terms indicating directions are used merely as a matter of convenience for explanation, and do not limit the locations or the orientations of the components of the refrigeration cycle apparatus according to each of the embodiments of the present disclosure. The terms indicating directions are, for example, "up", "down", "right", "left", "forward", and "backward". In addition, the following description concerning the refrigeration cycle apparatus according to each of the embodiments of the present disclosure is made merely as an example. The configurations of the refrigeration cycle apparatuses according to the embodiments of the present disclosure are not limited to those in the descriptions. In addition, the following descriptions concerning the embodiments are made by way of example with respect to the case where the refrigeration cycle apparatus according to each of the embodiments of the present disclosure is used as an air-conditioning apparatus. However, it suffices that the refrigeration cycle apparatus according to each of the embodiments of the present disclosure is used for refrigeration or air conditioning. That is, the refrigeration cycle apparatus according to each of the embodiments of the present disclosure can be used as, for example, a refrigerator, a freezer, a vending machine, an air-conditioning apparatus, a refrigeration apparatus, and a hot-water supply apparatus.

Embodiment 1

Fig. 1 is a refrigerant circuit diagram illustrating a refrigeration cycle apparatus according to Embodiment 1.
A refrigeration cycle apparatus 200 includes a heat medium circuit 8 in which a heat medium circulates. The heat medium circuit 8 includes a plurality of load-side heat exchangers and a plurality of use-side heat exchangers 3. Fig. 1 illustrates by way of example the refrigeration cycle apparatus 200 including two load-side heat exchangers and two use-side heat exchangers 3. The plurality of load-side heat exchangers are configured to cause heat exchange to be performed between a heat medium and first refrigerant different from the heat medium. A heat medium supplied from at least one of the load-side heat exchangers flows into the plurality of use-side heat exchangers 3.
The heat medium and the first refrigerant are not particularly limited; however, for example, the following substances are usable as the heat medium and the first refrigerant. For example, the heat medium is a calcium chloride solution, a sodium chloride solution, a magnesium chloride solution, brine containing ethylene glycol, antifreeze, or water. For example, the first refrigerant is olefin-based refrigerant, an ethylene-based refrigerant, an ethane-based refrigerant, propane, or dimethyl ether. In addition, for example, the first refrigerant is mixed refrigerant in which at least two of olefin-based refrigerant, ethylene-based refrigerant, ethane-based refrigerant, propane, and dimethyl ether are mixed. Such olefin-based refrigerant is, for example, tetrafluoropropene. In addition, tetrafluoropropene is, for example, HFO1234yf or HFO1234ze(E). Such ethylene-based refrigerant is, for example, difluoroethylene. Such ethane-based refrigerant is, for example, tetrafluoroethane.
It should be noted that at least some of the plurality of load-side heat exchangers of the heat medium circuit 8 are capable of supplying heat media having different temperatures. Hereinafter, one of the load-side heat exchangers will be referred to as a first load-side heat exchanger 1. In addition, hereinafter, of the load-side heat exchangers, one of load-side heat exchangers configured to supply a heat medium having a temperature different from that of a heat medium to be supplied by the first load-side heat exchanger 1 will be referred to as a second load-side heat exchanger 2.
In addition, hereinafter, one of the use-side heat exchangers 3 into which the heat medium supplied from the first load-side heat exchanger 1 flows may be referred to as a first use-side heat exchanger. Specifically, in the refrigeration cycle apparatus 200 as illustrated in Fig. 1, the use-side heat exchanger 3 located on the upper side of the figure is configured such that the heat medium supplied from the first load-side heat exchanger 1 flows into the use-side heat exchanger 3. Thus, in the refrigeration cycle apparatus 200 as illustrated in Fig. 1, the use-side heat exchanger 3 located on the upper side of the figure is the first use-side heat exchanger. In addition, hereinafter, one of the use-side heat exchangers into which the heat medium supplied from the second load-side heat exchanger 2 flows and which are other than the first use-side heat exchanger flows may be referred to as a second use-side heat exchanger. Specifically, in the refrigeration cycle apparatus 200 as illustrated in Fig. 1, the use-side heat exchanger 3 located on the lower side of the figure is configured such that the heat medium supplied from the second load-side heat exchanger 2 flows into that use-side heat exchanger 3. Thus, in the refrigeration cycle apparatus 200 illustrated as in Fig. 1, the use-side heat exchanger 3 located on the lower side of the figure is the second use-side heat exchanger.
Furthermore, the heat medium circuit 8 according to Embodiment 1 includes a joining portion 31, a branching portion 32, and a pump 6. The joining portion 31 causes the heat medium that flows out from the first use-side heat exchanger and the heat medium that flow out from the second use-side heat exchanger to join together. That is, in Embodiment 1, the joining portion 31 causes the heat medium that flows out from the use-side heat exchanger 3 located on the upper side of the figure and the heat medium that flows out from the use-side heat exchanger 3 located on the lower side of the figure to join together. The branching portion 32 causes a first heat medium pipe 8a through which the heat medium that flows out from the joining portion 31 flows to branch into a second heat medium pipe 8b connected to the first load-side heat exchanger 1 and a third heat medium pipe 8c connected to the second load-side heat exchanger 2. That is, the branching portion 32 connects the first load-side heat exchanger 1 and the second load-side heat exchanger 2 in parallel. The pump 6 is provided between the joining portion 31 and the branching portion 32 and circulates a heat medium in the heat medium circuit 8. In other words, the pump 6 is provided at the first heat medium pipe 8a.
A structure for causing the first refrigerant to flow in the first load-side heat exchanger 1 and the second load-side heat exchanger 2 is not particularly limited. The refrigeration cycle apparatus 200 according to Embodiment 1 includes a first refrigerant circuit 7 as a structure for causing the first refrigerant to flow in the first load-side heat exchanger 1 and the second load-side heat exchanger 2. The first refrigerant circuit 7 includes the first load-side heat exchanger 1 and the second load-side heat exchanger 2, and is a circuit in which the first refrigerant circulates. The configuration of the first refrigerant circuit 7 is not particularly limited, and in Embodiment 1, the first refrigerant circuit 7 is configured as follows.
The first refrigerant circuit 7 includes a compressor 14, a flow switching device 41, a heat-source-side heat exchanger 4, the first load-side heat exchanger 1, the second load-side heat exchanger 2, a first expansion device 21, and a second expansion device 22.
The compressor 14 sucks the first refrigerant, compresses the sucked first refrigerant to change it into high-temperature and high-pressure refrigerant, and discharges the high-temperature and high-pressure refrigerant. As the compressor 14, for example, a rotary compressor, a scroll compressor, a screw compressor, or a reciprocating compressor can be used. A discharge port and a suction port of the compressor 14 for the first refrigerant are connected to the flow switching device 41.
The flow switching device 41 is, for example, a four-way valve, and switches its flow passage for the first refrigerant to change the connection of the discharge port and suction port of the compressor 14. To be more specific, in Embodiment 1, when the flow passage of the flow switching device 41 is switched to a flow passage indicated by solid lines in Fig. 1, the discharge port of the compressor 14 is connected to the heat-source-side heat exchanger 4, and the suction port of the compressor 14 is connected to the second load-side heat exchanger 2; and when the flow passage of the flow switching device 41 is switched to a flow passage indicated by dashed lines in Fig. 1, the discharge port of the compressor 14 is connected to the second load-side heat exchanger 2, and the suction port of the compressor 14 is connected to the heat-source-side heat exchanger 4.
The flow switching device 41 is not limited to the four-way valve. The flow switching device 41 may be, for example, a two-way valve or a three-way valve. The same is true of flow switching devices to be described below that are other than the flow switching device 41.
The heat-source-side heat exchanger 4 operates as an evaporator or a radiator. When the heat-source-side heat exchanger 4 operates as an evaporator, the heat-source-side heat exchanger 4 causes heat exchange to be performed between the first refrigerant flowing in the heat-source-side heat exchanger 4 and outdoor air to evaporate and gasify the first refrigerant. Furthermore, when the heat-source-side heat exchanger 4 operates as a radiator, the heat-source-side heat exchanger 4 causes heat exchange to be performed between the refrigerant flowing in the heat-source-side heat exchanger 4 and outdoor air to condense and liquefy the first refrigerant. The operating state of the refrigeration cycle apparatus 200 in which the heat-source-side heat exchanger 4 operates as an evaporator and the operating state of the refrigeration cycle apparatus 200 in which the heat-source-side heat exchanger 4 operates as a radiator will be described later. Meanwhile, as the refrigerant, refrigerant that is condensed when flowing in the radiator and being cooled by a heat exchange target, and refrigerant that is not condensed when flowing in the radiator and being cooled by the heat exchange target are present. The following description concerning Embodiment 1 is made by way of example with respect to the case where refrigerant to be condensed in the radiator is used as the first refrigerant that circulates in the first refrigerant circuit 7. It should be noted that in the case where the refrigerant to be condensed in the radiator flows in the radiator, the radiator will also be referred to as a condenser.
In the past, as heat exchangers, heat exchangers having various configurations have been proposed, such as a finned tube heat exchanger, a microchannel heat exchanger, a shell and tube heat exchanger, a heat pipe heat exchanger, a double-pipe heat exchanger, and a plate heat exchanger. It is possible to select any of those heat exchangers as appropriate and to use the selected heat exchanger as the heat-source-side heat exchanger 4. In Embodiment 1, a fan 5 is provided adjacent to the heat-source-side heat exchanger 4 to improve the efficiency of heat exchange between the refrigerant and outdoor air in the heat-source-side heat exchanger 4. The configuration of the fan 5 is not particularly limited. It suffices that as the fan 5, for example, a propeller fan, a line flow fan (registered trademark), or a multi-blade centrifugal fan is selected on the basis of operating conditions such as the flow rate and the static pressure of outdoor air that is supplied to the heat-source-side heat exchanger 4. In addition, when the heat-source-side heat exchanger 4 is configured to exchange heat with a heat medium such as water, the heat medium may be supplied to the heat-source-side heat exchanger 4 by a pump, for example.
One of end portions of the heat-source-side heat exchanger 4 is connected to the flow switching device 41, and the other end portion of the heat-source-side heat exchanger 4 is connected to the first load-side heat exchanger 1 through the first expansion device 21.
The first expansion device 21 is provided between the heat-source-side heat exchanger 4 and the first load-side heat exchanger 1. The first expansion device 21 operates as a pressure reducing valve or an expansion valve and decompresses and expands the first refrigerant. The first expansion device 21 is, for example, an electric expansion valve capable of adjusting the flow rate of the first refrigerant. It should be noted that the first expansion device 21 is not limited to the electric expansion valve. For example, the first expansion device 21 may be a mechanical expansion valve using a diaphragm as a pressure receiving portion. In addition, for example, part of the first expansion device 21 may be a capillary tube. The same is true of the other expansion devices that will be described below.
The first load-side heat exchanger 1 operates as an evaporator or a radiator. When the first load-side heat exchanger 1 operates as an evaporator, the first load-side heat exchanger 1 causes heat exchange to be performed between the first refrigerant flowing in the first load-side heat exchanger 1 and the heat medium circulating in the heat medium circuit 8 to evaporate and gasify the first refrigerant. When the first load-side heat exchanger 1 operates as a radiator, the first load-side heat exchanger 1 causes heat exchange to be performed between the first refrigerant flowing in the first load-side heat exchanger 1 and the heat medium circulating in the heat medium circuit 8 to condense and liquefy the first refrigerant. The operating state of the refrigeration cycle apparatus 200 in the case where the first load-side heat exchanger 1 operates as an evaporator and the operating state of the refrigeration cycle apparatus 200 in the case where the first load-side heat exchanger 1 operates as a radiator will be described later.
In the past, as heat exchangers, various types of heat exchangers have been proposed. For example, the various types of heat exchangers are a finned tube heat exchanger, a microchannel heat exchanger, a shell and tube heat exchanger, a heat pipe heat exchanger, a double-pipe heat exchanger, and a plate heat exchanger. It is possible to appropriately select and use any of these heat exchangers as the first load-side heat exchanger 1. The same is true of the second load-side heat exchanger 2.
As described above, one of end portions of the first load-side heat exchanger 1 is connected to the heat-source-side heat exchanger 4 through the first expansion device 21, and the other end portion of the first load-side heat exchanger 1 is connected to the second load-side heat exchanger 2 through the second expansion device 22. That is, in the first refrigerant circuit 7 according to Embodiment 1, the first load-side heat exchanger 1 and the second load-side heat exchanger 2 are connected in series to the heat-source-side heat exchanger 4.
The second expansion device 22 is provided between the first load-side heat exchanger 1 and the second load-side heat exchanger 2. The second expansion device 22, as well as the first expansion device 21, operates as a pressure reducing valve or an expansion valve and decompresses and expands the first refrigerant.
The second load-side heat exchanger 2, as well as the first expansion device 21, operates as an evaporator or a radiator. When the second load-side heat exchanger 2 operates as an evaporator, the second load-side heat exchanger 2 causes heat exchange to be performed between the first refrigerant flowing in the second load-side heat exchanger 2 and the heat medium circulating in the heat medium circuit 8 to evaporate and gasify the first refrigerant. When the second load-side heat exchanger 2 operates as a radiator, the second load-side heat exchanger 2 causes heat exchange to be performed between the first refrigerant flowing in the second load-side heat exchanger 2 and the heat medium circulating in the heat medium circuit 8 to condense and liquefy the first refrigerant. The operating state of the refrigeration cycle apparatus 200 in the case where the second load-side heat exchanger 2 operates as an evaporator and the operating state of the refrigeration cycle apparatus 200 in the case where the second load-side heat exchanger 2 operates as a radiator will be described later.
As described above, one of end portions of the second load-side heat exchanger 2 is connected to the first load-side heat exchanger 1 through the second expansion device 22, and the other end portion of the second load-side heat exchanger 2 is connected to the flow switching device 41.
At least some of the above components of the refrigeration cycle apparatus 200 are mounted in a unit. In Embodiment 1, the refrigeration cycle apparatus 200 includes a heat source unit 201. In addition, the refrigeration cycle apparatus 200 includes heat load units 202 as units different from the heat source unit 201. In addition, the refrigeration cycle apparatus 200 includes, as a unit different from the heat source unit 201, a relay unit 203 connecting the heat source unit 201 and the heat load units 202. Then, the compressor 14, the flow switching device 41, the heat-source-side heat exchanger 4, and the fan 5 are provided in the heat source unit 201. The first expansion device 21, the second expansion device 22, the first load-side heat exchanger 1, the second load-side heat exchanger 2, the pump 6, the joining portion 31, and the branching portion 32 are provided in the relay unit 203. The use-side heat exchangers 3 are provided in the heat load units 202. In Embodiment 1, the use-side heat exchangers 3 are provided in the respective heat load units 202.
Furthermore, the refrigeration cycle apparatus 200 according to Embodiment 1 includes a controller 210 that controls the operating state of the refrigeration cycle apparatus 200. Specifically, the controller 210 causes the flow passage of the flow switching device 41 to be switched between the flow passages described above. In addition, the controller 210 starts and stops the compressor 14. The controller 210 may be configured to control the rotation speed of the compressor 14 during driving of the compressor 14, whereby it is possible to control the amount of the first refrigerant that is discharged from the compressor 14. Furthermore, the controller 210 controls the opening degree of each of the first expansion device 21 and the second expansion device 22. In addition, the controller 210 starts and stops the fan 5. The controller 210 may be configured to control the rotation speed of the fan 5 during driving of the fan 5. Also, the controller 210 starts and stops the pump 6. The controller 210 may be configured to control the rotation speed of the pump 6 during driving of the pump 6, whereby it is possible to control the amount of the heat medium that is discharged from the pump 6. The unit in which the controller 210 is mounted is not particularly limited, and in Embodiment 1, the controller 210 is mounted in the heat source unit 201.
The controller 210 is dedicated hardware or a central processing unit (CPU) that runs a program stored in memory. The CPU is also referred to as a central processing unit, a processing unit, an arithmetic unit, a microprocessor, a microcomputer, or a processor.
In the case where the controller 210 is dedicated hardware, the controller 210 corresponds to, for example, a single circuit, a composite circuit, an application specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or a combination of these circuits. Functional units of the controller 210 may be respective hardware or single hardware.
In the case where the controller 210 is a CPU, functions of the controller 210 are implemented by software, firmware, or a combination of software and firmware. Such software and firmware are each written as a program and stored in memory. The CPU reads and runs a program stored in the memory to fulfill an associated one of the functions of the controller 210. It should be noted that the memory is a nonvolatile or volatile semiconductor memory such as RAM, ROM, flash memory, EPROM, or EEPROM.
Some of the functions of the controller 210 may be implemented by dedicated hardware, and others of the functions of the controller 210 may be implemented by software or firmware.
Next, operations of the refrigeration cycle apparatus 200 will be described. First of all, a cooling-only operation of the refrigeration cycle apparatus 200 will be described. The cooling-only is an operation in which all the use-side heat exchangers mounted in the heat load unit or units 202 that are in in operation cool indoor air.
When the refrigeration cycle apparatus 200 performs the cooling-only operation, the first refrigerant circuit 7 operates as follows. In the first refrigerant circuit 7, the flow passage of the flow switching device 41 is switched to the flow passage indicated by the solid lines in Fig. 1. In addition, in the first refrigerant circuit 7, the heat-source-side heat exchanger 4 operates as a radiator, and the first load-side heat exchanger 1 and the second load-side heat exchanger 2 each operate as an evaporator.
When the compressor 14 is driven in the cooling-only operation, first refrigerant is discharged as high-temperature and high-pressure gas refrigerant from the discharge port of the compressor 14. The first refrigerant discharged from the compressor 14 flows into the heat-source-side heat exchanger 4 through the flow switching device 41. The first refrigerant that has flowed as the high-temperature and high-pressure gas refrigerant into the heat-source-side heat exchanger 4 is cooled and condensed by outdoor air supplied by the fan 5 to change into high-pressure liquid refrigerant. Then, after flowing out from the heat-source-side heat exchanger 4, the first refrigerant flows into the first expansion device 21. It should be noted that the first refrigerant that has flowed as the high-temperature and high-pressure gas refrigerant into the heat-source-side heat exchanger 4 may be cooled and condensed by outdoor air to change into two-phase gas-liquid refrigerant, which is a mixture of gas refrigerant and liquid refrigerant.
The first refrigerant that has flowed as the high-pressure liquid refrigerant into the first expansion device 21 is decompressed to change into low-pressure two-phase gas-liquid refrigerant. Then, after flowing out from the first expansion device 21, the first refrigerant flows as the low-pressure two-phase gas-liquid refrigerant in the first load-side heat exchanger 1 and the second load-side heat exchanger 2 in this order. In this case, for example, the second expansion device 22 is in a completely open state. In the process of flowing in the first load-side heat exchanger 1 and the second load-side heat exchanger 2, the first refrigerant that flows as the low-pressure two-phase gas-liquid refrigerant is heated by the heat medium in the heat medium circuit 8, whereby the liquid refrigerant of the low-pressure two-phase gas-liquid refrigerant is evaporated and the low-pressure two-phase gas-liquid refrigerant changes into low-pressure gas refrigerant. In other words, in the first load-side heat exchanger 1 and the second load-side heat exchanger 2, the heat medium in the heat medium circuit 8 is cooled by the first refrigerant in the first refrigerant circuit 7.
After flowing out from the second load-side heat exchanger 2, the first refrigerant that flows as the low-pressure gas refrigerant passes through the flow switching device 41, is sucked into the compressor 14 through the suction port of the compressor 14, and is re-compressed and then discharged by the compressor 14. Thereafter, this cycle is repeated in the first refrigerant circuit 7.
Furthermore, when the refrigeration cycle apparatus 200 performs the cooling-only operation, the heat medium circuit 8 operates as follows. Part of the heat medium discharged from a discharge port of the pump 6 flows into the first load-side heat exchanger 1 through the branching portion 32. In addition, the remaining part of the heat medium discharged from the discharge port of the pump 6 flows into the second load-side heat exchanger 2 through the branching portion 32.
The heat medium that has flowed into the first load-side heat exchanger 1 is cooled by the first refrigerant in the first refrigerant circuit 7. After flowing out from the first load-side heat exchanger 1, the heat medium flows into the use-side heat exchanger 3 located on the upper side of the figure and cools indoor air. That is, an indoor space where the use-side heat exchanger 3 is provided is cooled.
Similarly, the heat medium that has flowed into the second load-side heat exchanger 2 is cooled by the first refrigerant in the first refrigerant circuit 7. After flowing out from the second load-side heat exchanger 2, the heat medium flows into the use-side heat exchanger 3 located on the lower side of the figure and cools indoor air. That is, an indoor space where the use-side heat exchanger 3 is provided is cooled.
The heat media that have flowed out from the respective use-side heat exchangers 3 join together at the joining portion 31 to combine into a heat medium. This heat medium is then sucked into the pump 6 through the suction port of the pump 6 and is re-discharged from the pump 6. Thereafter, this cycle is repeated in the heat medium circuit 8.
Next, a heating-only operation by the refrigeration cycle apparatus 200 will be described. The heating-only operation is an operation in which all the use-side heat exchangers mounted in the heat load unit or units 202 that are in operation heat indoor air.
When the refrigeration cycle apparatus 200 performs the heating-only operation, the first refrigerant circuit 7 operates as follows. In the first refrigerant circuit 7, the flow passage of the flow switching device 41 is switched to the flow passage indicated by the dashed lines in Fig. 1. In addition, in the first refrigerant circuit 7, the first load-side heat exchanger 1 and the second load-side heat exchanger 2 each operate as a radiator, and the heat-source-side heat exchanger 4 operates as an evaporator.
When the compressor 14 is driven in the heating-only operation, the first refrigerant is discharged as high-temperature and high-pressure gas refrigerant from the compressor 14 through the discharge port thereof. The first refrigerant discharged from the compressor 14 flows in the second load-side heat exchanger 2 and the first load-side heat exchanger 1 in this order through the flow switching device 41. In this case, for example, the second expansion device 22 is in the completely open state. In the process of flowing in the second load-side heat exchanger 2 and the first load-side heat exchanger 1, the first refrigerant that flows as the high-temperature and high-pressure gas refrigerant is cooled and condensed by the heat medium in the heat medium circuit 8 to change into high-pressure liquid refrigerant. In other words, in the second load-side heat exchanger 2 and the first load-side heat exchanger 1, the heat medium in the heat medium circuit 8 is heated by the first refrigerant in the first refrigerant circuit 7. Then, after flowing out from the first load-side heat exchanger 1, the first refrigerant flows into the first expansion device 21.
The first refrigerant that has flowed as the high-pressure liquid refrigerant into the first expansion device 21 is decompressed to change into low-pressure two-phase gas-liquid refrigerant. Then, after flowing out from the first expansion device 21, the first refrigerant flows as the low-pressure two-phase gas-liquid refrigerant into the heat-source-side heat exchanger 4. The first refrigerant that has flowed as the low-pressure two-phase gas-liquid refrigerant into the heat-source-side heat exchanger 4 is heated by outdoor air supplied by the fan 5, whereby the liquid refrigerant of the low-pressure two-phase gas-liquid refrigerant is evaporated and the low-pressure two-phase gas-liquid refrigerant changes into low-pressure gas refrigerant.
After flowing out from the heat-source-side heat exchanger 4, the first refrigerant that flows as the low-pressure gas refrigerant passes through the flow switching device 41, is sucked into the compressor 14 through the suction port thereof, and is re-compressed and then discharged by the compressor 14. Thereafter, this cycle is repeated in the first refrigerant circuit 7.
Furthermore, when the refrigeration cycle apparatus 200 performs the heating-only operation, the heat medium circuit 8 operates as follows. Part of the heat medium discharged from the discharge port of the pump 6 flows into the first load-side heat exchanger 1 through the branching portion 32. In addition, the remaining part of the heat medium discharged from the discharge port of the pump 6 flows into the second load-side heat exchanger 2 through the branching portion 32.
The heat medium that has flowed into the first load-side heat exchanger 1 is heated by the first refrigerant in the first refrigerant circuit 7. After flowing out from the first load-side heat exchanger 1, the heat medium flows into the use-side heat exchanger 3 located on the upper side of the figure and heats indoor air. That is, the indoor space where the use-side heat exchanger 3 is provided is heated.
Similarly, the heat medium that has flowed into the second load-side heat exchanger 2 is heated by the first refrigerant in the first refrigerant circuit 7. After flowing out from the second load-side heat exchanger 2, the heat medium flows into the use-side heat exchanger 3 located on the lower side of the figure and heats indoor air. That is, the indoor space where the use-side heat exchanger 3 is provided is heated.
The heat media flow out from the respective use-side heat exchangers 3, and then join together at the joining portion 31 to combine into a heat medium. This heat medium is then sucked into the pump 6 through the suction port thereof and is re-discharged from the pump 6. Thereafter, this cycle is repeated in the heat medium circuit 8.
Next, a cooling and heating mixed operation of the refrigeration cycle apparatus 200 will be described. The cooling and heating mixed operation is an operation in which one or some of the use-side heat exchangers mounted in the heat load units 202 cool indoor air when the heat load units 202 are in operation and one or some of the use-side heat exchangers mounted in the heat load units 202 heat indoor air when the heat load units 202 are in operation.
When the refrigeration cycle apparatus 200 performs the cooling and heating mixed operation, the first refrigerant circuit 7 operates as follows. In the first refrigerant circuit 7, the flow passage of the flow switching device 41 is switched to the passage indicated by the solid lines in Fig. 1. In addition, in the first refrigerant circuit 7, the heat-source-side heat exchanger 4 and the first load-side heat exchanger 1 each operate as a radiator, and the second load-side heat exchanger 2 operates as an evaporator.
When the compressor 14 is driven in the cooling and heating mixed operation, the first refrigerant is discharged as high-temperature and high-pressure gas refrigerant from the compressor 14 through the discharge port thereof. The first refrigerant discharged from the compressor 14 flows into the heat-source-side heat exchanger 4 through the flow switching device 41. The first refrigerant that has flowed as the high-temperature and high-pressure gas refrigerant into the heat-source-side heat exchanger 4 is cooled and condensed by outdoor air supplied by the fan 5 to change into high-pressure two-phase gas-liquid refrigerant. Then, after flowing out from the heat-source-side heat exchanger 4, the first refrigerant flows into the first load-side heat exchanger 1 through the first expansion device 21. In this case, for example, the first expansion device 21 is in a completely open state.
The first refrigerant that has flowed as the high-pressure two-phase gas-liquid refrigerant into the first load-side heat exchanger 1 is cooled by the heat medium in the heat medium circuit 8, whereby gas refrigerant of the high-pressure two-phase gas-liquid refrigerant condenses and the high-pressure two-phase gas-liquid refrigerant changes into high-pressure liquid refrigerant. In other words, in the first load-side heat exchanger 1, the heat medium in the heat medium circuit 8 is heated by the first refrigerant in the first refrigerant circuit 7. Then, after flowing out from the first load-side heat exchanger 1, the first refrigerant flows into the second expansion device 22. The first refrigerant that has flowed as the high-pressure liquid refrigerant into the second expansion device 22 is decompressed to change into low-pressure two-phase gas-liquid refrigerant. Then, after flowing out from the second expansion device 22, the first refrigerant that flows as the low-pressure two-phase gas-liquid refrigerant flows into the second load-side heat exchanger 2. The first refrigerant that has flowed as the low-pressure two-phase gas-liquid refrigerant into the second load-side heat exchanger 2 is heated by the heat medium in the heat medium circuit 8, whereby liquid refrigerant of the low-pressure two-phase gas-liquid refrigerant evaporates and the low-pressure two-phase gas-liquid refrigerant changes into low-pressure gas refrigerant. In other words, in the second load-side heat exchanger 2, the heat medium in the heat medium circuit 8 is cooled by the first refrigerant in the first refrigerant circuit 7.
After flowing out from the second load-side heat exchanger 2, the first refrigerant that flows as the low-pressure gas refrigerant passes through the flow switching device 41, is sucked into the compressor 14 through the suction port thereof, and is re-compressed and then discharged by the compressor 14. Thereafter, this cycle is repeated in the first refrigerant circuit 7.
In addition, when the refrigeration cycle apparatus 200 performs the cooling and heating mixed operation, the heat medium circuit 8 operates as follows. Part of the heat medium discharged from the pump 6 flows into the first load-side heat exchanger 1 through the branching portion 32. In addition, the remaining part of the heat medium discharged from the discharge port of the pump 6 flows into the second load-side heat exchanger 2 through the branching portion 32.
The heat medium that has flowed into the first load-side heat exchanger 1 is heated by the first refrigerant in the first refrigerant circuit 7. After flowing out from the first load-side heat exchanger 1, the heat medium flows into the use-side heat exchanger 3 located on the upper side of the figure and heats indoor air. That is, the indoor space where the use-side heat exchanger 3 is provided is heated.
The heat medium that has flowed into the second load-side heat exchanger 2 is cooled by the first refrigerant in the first refrigerant circuit 7. After flowing out from the second load-side heat exchanger 2, the heat medium flows into the use-side heat exchanger 3 located on the lower side of the figure and cools indoor air. That is, the indoor space where the use-side heat exchanger 3 is provided is cooled.
The heat media flows out from the respective use-side heat exchangers 3, and then join together at the joining portion 31 to combine into a heat medium. This heat medium is then sucked into the pump 6 through the suction port thereof and is re-discharged from the pump 6. Thereafter, this cycle is repeated in the heat medium circuit 8.
The use-side heat exchanger 3 into which the heat medium supplied from the first load-side heat exchanger 1 flows and the use-side heat exchanger 3 into which the heat medium supplied from the second load-side heat exchanger 2 flows may be mounted in the same heat load unit 202. In this case, when the refrigeration cycle apparatus 200 performs an operation similar to the above cooling and heating mixed operation, one or more of the use-side heat exchangers 3 cools and dehumidifies indoor air, and one or more of the use-side heat exchangers 3 heats the dehumidified indoor air. It is therefore possible to return the heated air to the indoor space. Accordingly, in the case where the use-side heat exchanger 3 into which the heat medium supplied from the first load-side heat exchanger 1 flows and the use-side heat exchanger 3 into which the heat medium supplied from the second load-side heat exchanger 2 flows are mounted in the same heat load unit 202, it is possible to perform a dehumidifying operation to dehumidify air in the indoor space where the heat load unit 202 is provided.
In addition, the refrigeration cycle apparatus 200 according to Embodiment 1 can also perform the cooling and heating mixed operation or the dehumidifying operation by switching the flow passage of the flow switching device 41 to the flow passage indicated by the dashed lines in Fig. 1 and controlling the opening degree of the first expansion device 21. In this case, in the first refrigerant circuit 7, the second load-side heat exchanger 2 operates as a radiator, and the heat-source-side heat exchanger 4 and the first load-side heat exchanger 1 each operate as an evaporator.
As described above, the refrigeration cycle apparatus 200 according to Embodiment 1 includes the heat medium circuit 8 in which a heat medium different from the first refrigerant circulates. The heat medium circuit 8 includes the plurality of load-side heat exchangers and the plurality of use-side heat exchangers 3. The plurality of load-side heat exchangers cause heat exchange to be performed between the first refrigerant and the heat medium. The heat medium supplied from at least one of the load-side heat exchangers flows into the plurality of use-side heat exchangers 3. The first load-side heat exchanger 1, the first use-side heat exchanger, the second load-side heat exchanger 2, and the second use-side heat exchanger are defined as follows. One of the load-side heat exchangers is the first load-side heat exchanger 1. One of the use-side heat exchangers 3 into which the heat medium supplied from the first load-side heat exchanger 1 flows is the first use-side heat exchanger. Of the load-side heat exchangers, one of load-side heat exchangers configured to supply the heat medium having a temperature different from that of the heat medium that is supplied by the first load-side heat exchanger 1 is the second load-side heat exchanger 2. Of the use-side heat exchangers 3 into which the heat medium supplied from the second load-side heat exchanger 2 flows, one of the use-side heat exchangers that are other than the first use-side heat exchanger is the second use-side heat exchanger. In addition, the heat medium circuit 8 includes the joining portion 31, the branching portion 32, and the pump 6. At the joining portion 31, the heat medium that flows out from the first use-side heat exchanger and the heat medium that flows out from the second use-side heat exchanger join together. The branching portion 32 causes the first heat medium pipe 8a in which the medium that flows out from the joining portion 31 flows to branch into the second heat medium pipe 8b connected to the first load-side heat exchanger 1 and the third heat medium pipe 8c connected to the second load-side heat exchanger 2. The branching portion 32 connects the first load-side heat exchanger 1 and the second load-side heat exchanger 2 in parallel. The pump 6 is provided between the joining portion 31 and the branching portion 32 and is configured to circulate the heat medium.
In the case where the first load-side heat exchanger 1 and the second load-side heat exchanger 2 are defined as described above, in an existing refrigeration cycle apparatus, a heat medium circuit includes a pump configured to supply the heat medium to the first load-side heat exchanger 1 and a pump configured to supply the heat medium to the second load-side heat exchanger 2. In other words, the heat medium circuit of the existing refrigeration cycle apparatus needs to supply the heat media by using the different respective pumps to the first load-side heat exchanger 1 and the second load-side heat exchanger 2. It should be noted that the pumps configured to supply the heat media to the load-side heat exchangers are expensive. In addition, in the case where the number of pumps configured to supply the heat media to the load-side heat exchangers increases, the probability of occurrence of a pump failure also increases. Thus, in the existing refrigeration cycle apparatus, the manufacturing cost increases and the reliability decreases.
By contrast, in the heat medium circuit 8 of the refrigeration cycle apparatus 200 according to Embodiment 1, the heat media can be supplied to the first load-side heat exchanger 1 and the second load-side heat exchanger 2 by the one pump 6. Thus, in the refrigeration cycle apparatus 200 according to Embodiment 1, the number of pumps 6 included in the heat medium circuit 8 is smaller than in the existing refrigeration cycle apparatuses. Therefore, in the refrigeration cycle apparatus 200 according to Embodiment 1, the manufacturing cost is lower and the reliability is higher than in the existing refrigeration cycle apparatus.
The refrigeration cycle apparatus 200 according to Embodiment 1 has been described above. Finally, a modification of the refrigeration cycle apparatus 200 according to Embodiment 1 will be introduced. In the modification of the refrigeration cycle apparatus 200 according to Embodiment 1, it is possible to obtain further advantages in addition to the above advantages in which the manufacturing cost is reduced and the reliability is improved.
Fig. 2 is a refrigerant circuit diagram illustrating the modification of the refrigeration cycle apparatus according to Embodiment 1.
In the refrigeration cycle apparatus 200 as illustrated in Fig. 2, a heat-medium inlet of the first use-side heat exchanger and a heat-medium inlet of the second use-side heat exchanger are connected with a heat-medium outlet of the first load-side heat exchanger 1 and a heat-medium outlet of the second load-side heat exchanger 2. That is, in the refrigeration cycle apparatus 200 as illustrated in Fig. 2, a heat-medium inlet of the use-side heat exchanger 3 located on the upper side of the figure and an heat-medium inlet of the use-side heat exchanger 3 located on the lower side of the figure are connected with the heat-medium outlet of the first load-side heat exchanger 1 and the heat-medium outlet of the second load-side heat exchanger 2.
Then, the heat medium circuit 8 of the refrigeration cycle apparatus 200 as illustrated in Fig. 2 includes first flow control units 60 provided on the heat-medium inlet side of the first use-side heat exchanger and the heat-medium inlet side of the second use-side heat exchanger. The first flow control units 60 are configured to control the flow rate of the heat medium supplied from the first load-side heat exchanger 1 and that of the heat medium supplied from the second load-side heat exchanger 2. The first flow control units 60 are controlled by the controller 210.
That is, the heat medium circuit 8 as illustrated in Fig. 2 is configured to enable the heat media to flow from both the first load-side heat exchanger 1 and the second load-side heat exchanger 2 into both the two use-side heat exchangers 3. In this configuration, when the heat medium supplied from the first load-side heat exchanger 1 flows into the use-side heat exchanger 3 located on the upper side of the figure and the heat medium supplied from the second load-side heat exchanger 2 flows into the use-side heat exchanger 3 located on the lower side of the figure, the use-side heat exchanger 3 located on the upper side of the figure is the first use-side heat exchanger, and the use-side heat exchanger 3 located on the lower side of the figure is the second use-side heat exchanger. In addition, when the heat medium supplied from the first load-side heat exchanger 1 flows into the use-side heat exchanger 3 located on the lower side of the figure and the heat medium supplied from the second load-side heat exchanger 2 flows into the use-side heat exchanger 3 located on the upper side of the figure, the use-side heat exchanger 3 located on the lower side of the figure is the first use-side heat exchanger, and the use-side heat exchanger 3 located on the upper side of the figure is the second use-side heat exchanger. In addition, when the heat media supplied from the first load-side heat exchanger 1 and the second load-side heat exchanger 2 flow into both the two use-side heat exchangers 3, one of the two use-side heat exchangers 3 is the first use-side heat exchanger, and the other of the two use-side heat exchangers 3 is the second use-side heat exchanger.
The configuration of each of first flow control units 60 is not particularly limited. In the refrigeration cycle apparatus 200 as illustrated in Fig. 2, each of the first flow control units 60 includes a joining portion 33, a flow control device 61, and a flow control device 62. The joining portion 33 is located on the heat-medium inlet side of an associated one of the use-side heat exchangers 3, and at the joining portion 33, a heat medium pipe that extends from the heat-medium outlet of the first load-side heat exchanger 1, toward the use-side heat exchanger 3, and a heat medium pipe that extends from the heat-medium outlet of the second load-side heat exchanger 2 toward the use-side heat exchanger 3, join together. The flow control device 61 is provided at the heat medium pipe that extends toward the use-side heat exchanger 3, from the heat-medium outlet of the first load-side heat exchanger 1 and is configured to adjust the flow rate of the heat medium that is supplied from the first load-side heat exchanger 1 to the use-side heat exchanger 3. The flow control device 62 is provided at the heat medium pipe that extends toward the use-side heat exchanger 3, from the heat-medium outlet of the second load-side heat exchanger 2, and is configured to adjust the flow rate of the heat medium that is supplied from the second load-side heat exchanger 2 to the use-side heat exchanger 3.
In the following, for example, it is assumed as an operating state that in the cooling and heating mixed operation, the first load-side heat exchanger 1 is required to have a high heat exchange capacity and the second load-side heat exchanger 2 is required to have a low heat exchange capacity. As described above, the existing refrigeration cycle apparatus needs to supply the heat media to the first load-side heat exchanger 1 and the second load-side heat exchanger 2 by using the respective pumps. Thus, when the existing refrigeration cycle apparatus is in the above assumed operating state, in some cases, the pump that supplies the heat medium to the first load-side heat exchanger 1 lacks sufficient capacity, while the pump that supplies the heat medium to the second load-side heat exchanger 2 has surplus capacity. That is, when the existing refrigeration cycle apparatus is in the above assumed operating state, in some cases, although the pump that supplies the heat medium to the second load-side heat exchanger 2 has sufficient capacity, the amount of the heat medium supplied to the first load-side heat exchanger 1 is insufficient. In such a manner, when the amount of the heat medium supplied to the first load-side heat exchanger 1 is insufficient, the energy efficiency of the refrigeration cycle apparatus decreases. In the existing refrigeration cycle apparatus, as a method of reducing a decrease in the energy efficiency, it is conceivable to enlarge each of the pumps. However, if each of the pumps is enlarged, the refrigeration cycle apparatus will become larger.
By contrast, in the refrigeration cycle apparatus 200 as illustrated in Fig. 2, the first flow control unit 60 is capable of adjusting the distribution ratio between the heat medium that is supplied to the first load-side heat exchanger 1 and the heat medium that is supplied to the second load-side heat exchanger 2. Thus, in the refrigeration cycle apparatus 200 as illustrated in Fig. 2, it is possible to reduce occurrence of insufficiency of the amount of the heat medium supplied to the first load-side heat exchanger 1 without enlarging the pump 6. Therefore, it is possible to reduce a decrease in energy efficiency of the refrigeration cycle apparatus 200 as illustrated in Fig. 2 and an increase in size of the refrigeration cycle apparatus 200. The flow control device 61 and the flow control device 62 each may be either an opening-degree control valve whose opening degree can be controlled or an on-off valve that can only be opened and closed. In the case where on-off valves are used as the flow control device 61 and the flow control device 62, by controlling the number of the use-side heat exchangers 3 to which the heat medium is supplied from the first load-side heat exchanger 1 is controlled, it is possible to control the distribution ratio between the heat medium that is supplied to the first load-side heat exchanger 1 and the heat medium that is supplied to the second load-side heat exchanger 2.

Embodiment 2

The configuration of the first refrigerant circuit 7 is not limited to that in Embodiment 1. For example, the first refrigerant circuit 7 may be configured as described below regarding Embodiment 2. Regarding Embodiment 2, matters that are the same as those in Embodiment 1 will not be particularly described. In addition, in Embodiment 2, components that have the same functions as in Embodiment 1 will be denoted by the same reference signs.
Figs. 3 to 5 are refrigerant circuit diagrams illustrating examples of a refrigeration cycle apparatus according to Embodiment 2.
The refrigeration cycle apparatus 200 according to Embodiment 2, as well as the refrigeration cycle apparatus 200 according to Embodiment 1, is capable of performing the cooling-only operation, the heating-only operation, and the cooling and heating mixed operation. Furthermore, the refrigeration cycle apparatus 200 according to Embodiment 2, as well as the refrigeration cycle apparatus 200 according to Embodiment 1, can perform a dehumidifying operation to dehumidify air in an indoor space where the heat load unit 202 is provided, by mounting the use-side heat exchanger 3 into which the heat medium supplied from the first load-side heat exchanger 1 flows and the use-side heat exchanger 3 into which the heat medium supplied from the second load-side heat exchanger 2 flows in the same heat load unit 202, and by causing the refrigeration cycle apparatus 200 according to Embodiment 2 to perform an operation similar to the cooling and heating mixed operation.
Specifically, in the case where the refrigeration cycle apparatus 200 as illustrated in Fig. 3 performs the cooling-only operation, the flow passage of a flow switching device 42 is switched to a flow passage indicated by solid lines in Fig. 3, the flow passage of a flow switching device 43 is switched to a flow passage indicated by dashed lines in Fig. 3, at least one of an opening and closing device 51 and an opening and closing device 52 is made to be in an open state, and at least one of an opening and closing device 53 and an opening and closing device 54 is made to be in an open state. As a result, in the first refrigerant circuit 7, the heat-source-side heat exchanger 4 operates as a radiator, and the first load-side heat exchanger 1 and the second load-side heat exchanger 2 each operate as an evaporator. Then, the refrigeration cycle apparatus 200 as illustrated in Fig. 3 can perform the cooling-only operation. The first refrigerant that flows from the heat-source-side heat exchanger 4 into the first load-side heat exchanger 1 is decompressed and expanded by an expansion device 17. In addition, the first refrigerant that flows from the heat-source-side heat exchanger 4 into the second load-side heat exchanger 2 is decompressed and expanded by an expansion device 18.
Furthermore, in the case where the refrigeration cycle apparatus 200 as illustrated in Fig. 3 performs the heating-only operation, the flow passage of the flow switching device 42 is switched to a flow passage indicated by dashed lines in Fig. 3, the flow passage of the flow switching device 43 is switched to a flow passage indicated by solid lines in Fig. 3, the opening and closing device 51 is made to be in the open state, the opening and closing device 52 is made to be in a closed state, the opening and closing device 53 is made to be in a closed state, and the opening and closing device 54 is made to be in the open state. As a result, in the first refrigerant circuit 7, the first load-side heat exchanger 1 and the second load-side heat exchanger 2 each operate as a radiator, and the heat-source-side heat exchanger 4 operates as an evaporator. As a result, the refrigeration cycle apparatus 200 as illustrated in Fig. 3 can perform the heating-only operation. After flowing out from the first load-side heat exchanger 1, the first refrigerant that will flow into the heat-source-side heat exchanger 4 is decompressed and expanded by the expansion device 17. In addition, after flowing out from the second load-side heat exchanger 2, the first refrigerant that will flow into the heat-source-side heat exchanger 4 is decompressed and expanded by the expansion device 18.
In the case where the refrigeration cycle apparatus 200 as illustrated in Fig. 3 performs the cooling and heating mixed operation, the flow passage of the flow switching device 42 is switched to the flow passage indicated by the dashed lines in Fig. 3, the flow passage of the flow switching device 43 is switched to the flow passage indicated by the solid lines in Fig. 3, the opening and closing device 51 is made to be in the open state, the opening and closing device 52 is made to be in the closed state, the opening and closing device 53 is made to be in the open state, and the opening and closing device 54 is made to be in a closed state. Thus, in the first refrigerant circuit 7, the first load-side heat exchanger 1 operates as a radiator, and the heat-source-side heat exchanger 4 and the second load-side heat exchanger 2 each operate as an evaporator. Then, the refrigeration cycle apparatus 200 as illustrated in Fig. 3 can perform the cooling and heating mixed operation. It should be noted that after flowing out from the first load-side heat exchanger 1, the first refrigerant that will flow into the heat-source-side heat exchanger 4 and the second load-side heat exchanger 2 is decompressed and expanded by the expansion device 17, for example.
In the case where the refrigeration cycle apparatus 200 as illustrated in Fig. 3 performs the cooling and heating mixed operation, the flow passage of the flow switching device 42 is switched to the flow passage indicated by the dashed lines in Fig. 3, the flow passage of the flow switching device 43 is switched to the flow passage indicated by the dashed lines in Fig. 3, the opening and closing device 51 is made to be in a closed state, the opening and closing device 52 is made to be in the open state, the opening and closing device 53 is made to be in the closed state, and the opening and closing device 54 is made to be in the open state. Thus, in the first refrigerant circuit 7, the heat-source-side heat exchanger 4 and the second load-side heat exchanger 2 each operate as a radiator, and the first load-side heat exchanger 1 operates as an evaporator. Then, the refrigeration cycle apparatus 200 as illustrated in Fig. 3 can perform the cooling and heating mixed operation. It should be noted that after flowing from the heat-source-side heat exchanger 4 and the second load-side heat exchanger 2, the first refrigerant that will flow into the first load-side heat exchanger 1 is decompressed and expanded by the expansion device 17, for example.
Specifically, in the case where the refrigeration cycle apparatus 200 as illustrated in each of Figs. 4 and 5 performs the cooling-only operation, the flow passage of the flow switching device 42 is switched to the flow passage indicated by the solid lines in Figs. 4 and 5, and the flow passage of the flow switching device 43 is switched to the flow passage indicated by the solid lines in Figs. 4 and 5. Thus, in the first refrigerant circuit 7, the heat-source-side heat exchanger 4 operates as a radiator, and the first load-side heat exchanger 1 and the second load-side heat exchanger 2 each operate as an evaporator. Then, the refrigeration cycle apparatus 200 as illustrated in each of Figs. 4 and 5 can perform the cooling-only operation. After flowing out from the heat-source-side heat exchanger 4, the first refrigerant that will flow into the first load-side heat exchanger 1 is decompressed and expanded by an expansion device 17. In addition, after flowing out from the heat-source-side heat exchanger 4, the first refrigerant that will flow into the second load-side heat exchanger 2 is decompressed and expanded by an expansion device 18.
In the case where the refrigeration cycle apparatus 200 as illustrated in each of Figs. 4 and 5 performs the heating-only operation, the flow passage of the flow switching device 42 is switched to the flow passage indicated by the dashed lines in Figs. 4 and 5, and the flow passage of the flow switching device 43 is switched to the flow passage indicated by the dashed lines in Figs. 4 and 5. Thus, in the first refrigerant circuit 7, the first load-side heat exchanger 1 and the second load-side heat exchanger 2 each operate as a radiator, and the heat-source-side heat exchanger 4 operates as an evaporator. Then, the refrigeration cycle apparatus 200 as illustrated in each of Figs. 4 and 5 can perform the heating-only operation. After flowing out from the first load-side heat exchanger 1, the first refrigerant that will flow into the heat-source-side heat exchanger 4 is decompressed and expanded by the expansion device 17. In addition, after flowing out from the second load-side heat exchanger 2, the first refrigerant that will flow into the heat-source-side heat exchanger 4 is decompressed and expanded by the expansion device 18.
In the case where the refrigeration cycle apparatus 200 as illustrated in each of Figs. 4 and 5 performs the cooling and heating mixed operation, the flow passage of the flow switching device 42 is switched to the flow passage indicated by the dashed lines in Figs. 4 and 5, and the flow passage of the flow switching device 43 is switched to the flow passage indicated by the solid lines in Figs. 4 and 5. Thus, in the first refrigerant circuit 7, the first load-side heat exchanger 1 operates as a radiator, and the heat-source-side heat exchanger 4 and the second load-side heat exchanger 2 each operate as an evaporator. Then, the refrigeration cycle apparatus 200 as illustrated in each of Figs. 4 and 5 can perform the cooling and heating mixed operation. After flowing out from the first load-side heat exchanger 1, the first refrigerant that will flow into the heat-source-side heat exchanger 4 and the second load-side heat exchanger 2 is decompressed and expanded by the expansion device 17, for example.
In the case where the refrigeration cycle apparatus 200 as illustrated in each of Figs. 4 and 5 performs the cooling and heating mixed operation, the flow passage of the flow switching device 42 is switched to the flow passage indicated by the solid lines in Figs. 4 and 5, and the flow passage of the flow switching device 43 is switched to the flow passage indicated by the dashed lines in Figs. 4 and 5. Thus, in the first refrigerant circuit 7, the heat-source-side heat exchanger 4 and the second load-side heat exchanger 2 each operate as a radiator, and the first load-side heat exchanger 1 operates as an evaporator. Then, the refrigeration cycle apparatuses 200 as illustrated in Figs. 4 and 5 can perform the cooling and heating mixed operation. After flowing out from the heat-source-side heat exchanger 4 and the second load-side heat exchanger 2, the first refrigerant that will flows into the first load-side heat exchanger 1 is decompressed and expanded by the expansion device 17, for example.
It should be noted that in the first refrigerant circuit 7 of the refrigeration cycle apparatus 200 according to Embodiment 2, in the case where either the cooling-only operation or a heating operation is performed, the first load-side heat exchanger 1 and the second load-side heat exchanger 2 are connected in parallel to the heat-source-side heat exchanger 4. In other words, in the first refrigerant circuit 7 of the refrigeration cycle apparatus 200 according to Embodiment 2, in the case where the first load-side heat exchanger 1 and the second load-side heat exchanger 2 each operate as a radiator, and in the case where the first load-side heat exchanger 1 and the second load-side heat exchanger 2 each operate as an evaporator, the first load-side heat exchanger 1 and the second load-side heat exchanger 2 are connected in parallel to the heat-source-side heat exchanger 4.
In the refrigeration cycle apparatus 200 according to Embodiment 1, in the case where the cooling-only operation is performed, the first load-side heat exchanger 1 and the second load-side heat exchanger 2 that each operate as an evaporator are connected in series. In this case, the state of the first refrigerant that flows into the second load-side heat exchanger 2 varies depending on the load on the first load-side heat exchanger 1. In addition, in the refrigeration cycle apparatus 200 according to Embodiment 1, in the case where the heating-only operation is performed, the first load-side heat exchanger 1 and the second load-side heat exchanger 2 that each operate as an evaporator are connected in series. In this case, the state of the first refrigerant that flows into the first load-side heat exchanger 1 varies depending on the load on the second load-side heat exchanger 2. Therefore, in the refrigeration cycle apparatus 200 according to Embodiment 1, in the case where the cooling-only operation or the heating operation is performed, in some cases, the distribution ratio between the heat medium that is supplied to the first load-side heat exchanger 1 and the heat medium that is supplied to the second load-side heat exchanger 2 needs to be adjusted using, for example, the first flow control units 60, by the heat exchange capacities of the first load-side heat exchanger 1 and the second load-side heat exchanger 2. However, when the distribution ratio between the heat medium that is supplied to the first load-side heat exchanger 1 and the heat medium that is supplied to the second load-side heat exchanger 2 is adjusted, the flow resistance of the heat medium in the heat medium circuit 8 is increased, thus reducing the flow rate of the heat medium. As a result, the energy efficiency of the refrigeration cycle apparatus 200 is reduced.
By contrast, in the refrigeration cycle apparatus 200 according to Embodiment 2, as described above, in the case where the cooling-only operation or the heating operation is performed, the first load-side heat exchanger 1 and the second load-side heat exchanger 2 are connected in parallel to the heat-source-side heat exchanger 4. Thus, in the refrigeration cycle apparatus 200 according to Embodiment 2, in the case where the cooling-only operation or the heating operation is performed, it is possible to supply the first refrigerant the state of which does not vary depending on the load on one of the first load-side heat exchanger 1 and the second load-side heat exchanger 2 to the other of the first load-side heat exchanger 1 and the second load-side heat exchanger 2. Therefore, the refrigeration cycle apparatus 200 according to Embodiment 2 does not require a mechanism that adjusts the distribution ratio between the heat medium that is supplied to the first load-side heat exchanger 1 and the heat medium that is supplied to the second load-side heat exchanger 2, in the case where the cooling-only operation or the heating operation is performed. Thus, the refrigeration cycle apparatus 200 according to Embodiment 2 is improved in energy efficiency, as compared with the refrigeration cycle apparatus 200 that is configured such that the first load-side heat exchanger 1 and the second load-side heat exchanger 2 are connected in series in the case where the cooling-only operation or the heating operation is performed. It should be noted that as illustrated in Fig. 6, in the case where the refrigeration cycle apparatus 200 according to Embodiment 2 includes the first flow control units 60, it suffices that the flow control devices 61 and the flow control devices 62 are completely opened.
Furthermore, in the first refrigerant circuit 7 of the refrigeration cycle apparatus 200 according to Embodiment 2, in the case where the cooling and heating mixed operation or the dehumidifying operation is performed, the heat-source-side heat exchanger 4 and the second load-side heat exchanger 2 are connected in parallel to the first load-side heat exchanger 1. In other words, in the first refrigerant circuit 7 of the refrigeration cycle apparatus 200 according to Embodiment 2, in the case where the first load-side heat exchanger 1 operates as one of a radiator and an evaporator and the heat-source-side heat exchanger 4 and the second load-side heat exchanger 2 operate as the other of the radiator and the evaporator, the heat-source-side heat exchanger 4 and the second load-side heat exchanger 2 are connected in parallel to the first load-side heat exchanger 1.
In the cooling and heating mixed operation or the dehumidifying operation, in the case where the heat-source-side heat exchanger 4 and the second load-side heat exchanger 2 are connected in series to the first load-side heat exchanger 1, the capacity of the second load-side heat exchanger 2 may be insufficient. For example, In the case where the heat-source-side heat exchanger 4 and the second load-side heat exchanger 2 are connected in series to the first load-side heat exchanger 1, when the load required for cooling is greater than the load required for heating, the heat-source-side heat exchanger 4 and the second load-side heat exchanger 2 each operate as a radiator. In this case, the first refrigerant that is gas refrigerant discharged from the compressor 14 is condensed in the heat-source-side heat exchanger 4 to change into two-phase gas-liquid refrigerant, and this two-phase gas-liquid refrigerant then flows into the second load-side heat exchanger 2. That is, the first refrigerant whose amount of gas is small flows into the second load-side heat exchanger 2. Thus, the capacity of the second load-side heat exchanger 2 may be insufficient. In order to compensate for the insufficiency of the capacity, it is necessary to increase the rotation speed of the compressor 14. This, however, reduces the energy efficiency of the refrigeration cycle apparatus 200.
By contrast, in the refrigeration cycle apparatus 200 according to Embodiment 2, as described above, in the case where the cooling and heating mixed operation or the dehumidifying operation is performed, the heat-source-side heat exchanger 4 and the second load-side heat exchanger 2 are connected in parallel to the first load-side heat exchanger 1. Thus, in the refrigeration cycle apparatus 200 according to Embodiment 2, in the case where the heat-source-side heat exchanger 4 and the second load-side heat exchanger 2 operate as a radiator, the first refrigerant that is gas refrigerant discharged from the compressor 14 flows into both the heat-source-side heat exchanger 4 and the second load-side heat exchanger 2. Therefore, the refrigeration cycle apparatus 200 according to Embodiment 2 can reduce occurrence of the insufficiency of the capacity of the second load-side heat exchanger 2 in the case where the cooling and heating mixed operation or the dehumidifying operation is performed. Thus, the refrigeration cycle apparatus 200 according to Embodiment 2 is improved in energy efficiency, as compared with the refrigeration cycle apparatus 200 in which the heat-source-side heat exchanger 4 and the second load-side heat exchanger 2 are connected in series in the case where the cooling and heating mixed operation or the dehumidifying operation is performed.

Embodiment 3

In the case where the refrigeration cycle apparatus 200 is configured as described below regarding Embodiment 3, it is further improved in energy efficiency. Regarding Embodiment 3, matters that are the same as those in Embodiment 1 and/or Embodiment 2 will not particularly be described. In addition, regarding Embodiment 3, components that have the same functions as those in Embodiment 1 and/or Embodiment 2 will be denoted by the same reference signs.
Fig. 6 is a refrigerant circuit diagram illustrating a refrigeration cycle apparatus according to Embodiment 3.
In the heat medium circuit 8 of the refrigeration cycle apparatus 200 according to Embodiment 3, a heat-medium outlet of the first use-side heat exchanger and a heat-medium outlet of the second use-side heat exchanger are connected with a fourth heat medium pipe 8d connected with the joining portion 31 and a fifth heat medium pipe 8e connected with the joining portion 31. In other words, in the heat medium circuit 8 of the refrigeration cycle apparatus 200 according to Embodiment 3, the outlets of the two use-side heat exchangers 3 are connected with the fourth heat medium pipe 8d connected with the joining portion 31 and the fifth heat medium pipe 8e connected with the joining portion 31. In Embodiment 3, end portions of the fourth heat medium pipe 8d and the fifth heat medium pipe 8e, which are closer to the use-side heat exchanger 3, are formed as a common heat medium pipe. In other words, in Embodiment 3, the heat medium pipe extending from the use-side heat exchanger 3 toward the joining portion 31 branches into the fourth heat medium pipe 8d and the fifth heat medium pipe 8e at a branching portion 34.
In addition, the heat medium circuit 8 of the refrigeration cycle apparatus 200 according to Embodiment 3 includes second flow control units 65 provided on a heat-medium outlet side of the first use-side heat exchanger and a heat-medium outlet side of the second use-side heat exchanger. The second flow control units 65 are each configured to adjust the flow rate of the heat medium that flows into the fourth heat medium pipe 8d and the flow rate of the heat medium that flows into the fifth heat medium pipe 8e. Each of the second flow control units 65 are controlled by the controller 210.
The configuration of the second flow control unit 65 is not particularly limited. In the refrigeration cycle apparatus 200 according to Embodiment 3, the second flow control unit 65 includes a flow control device 66 and a flow control device 67. The flow control device 66 is provided at the fourth heat medium pipe 8d and adjusts the flow rate of the heat medium that flows from the use-side heat exchanger 3 into the fourth heat medium pipe 8d. The flow control device 67 is provided at the fifth heat medium pipe 8e and adjusts the flow rate of the heat medium that flows from the use-side heat exchanger 3 into the fifth heat medium pipe 8e.
Furthermore, the refrigeration cycle apparatus 200 according to Embodiment 3 includes a second refrigerant circuit 9 in which second refrigerant circulates. The second refrigerant is not particularly limited, but, for example, the following substances can be usable as the second refrigerant. For example, the first refrigerant is olefin-based refrigerant, ethylene-based refrigerant, ethane-based refrigerant, propane, or dimethyl ether. Alternatively, for example, the first refrigerant is mixed refrigerant in which at least two of olefin-based refrigerant, ethylene-based refrigerant, ethane-based refrigerant, propane, and dimethyl ether are mixed. The second refrigerant may be the same as or different from the first refrigerant.
The second refrigerant circuit 9 includes a compressor 16 that circulates the second refrigerant, an expansion device 20 that decompresses and expands the second refrigerant, a first heat recovery heat exchanger 11, and a second heat recovery heat exchanger 12. The first heat recovery heat exchanger 11 is provided between the second use-side heat exchanger and the heat-medium outlet of the second load-side heat exchanger 2, and causes heat exchange to be performed between the second refrigerant and the heat medium. The second heat recovery heat exchanger 12 causes heat exchange to be performed between the second refrigerant and the heat medium that flows through the fifth heat medium pipe 8e. It should be noted that starting and stopping of the compressor 16 are controlled by the controller 210. The controller 210 may be configured to control the rotation speed of the compressor 16 during driving of the compressor 16.
When one of the first heat recovery heat exchanger 11 and the second heat recovery heat exchanger 12 operates as a radiator, the other of the first heat recovery heat exchanger 11 and the second heat recovery heat exchanger 12 operates as an evaporator. The second refrigerant circuit 9 according to Embodiment 3 includes a flow switching device 45 that enables the function of the first heat recovery heat exchanger 11 and that of the second heat recovery heat exchanger 12 to be interchanged. To be more specific, for example, in the case where the first heat recovery heat exchanger 11 operates as a radiator and the second heat recovery heat exchanger 12 operates as an evaporator, when the flow passage of the flow switching device 45 is switched, the first heat recovery heat exchanger 11 operates as an evaporator and the second heat recovery heat exchanger 12 operates as a radiator. It should be noted that the controller 210 performs switching between the flow passages of the flow switching device 45.
The second refrigerant circuit 9 operates as follows. The second refrigerant circuit 9 operates in such a manner as to cause the difference between the temperature of the heat medium that flows through the fifth heat medium pipe 8e toward the joining portion 31 after passing through the second heat recovery heat exchanger 12 and the temperature of the heat medium that flows through the fourth heat medium pipe 8d toward the joining portion 31 to reach a predetermined temperature difference. The method for measuring the temperature of the heat medium that flows through the fifth heat medium pipe 8e toward the joining portion 31 after passing through the second heat recovery heat exchanger 12 is not particularly limited. In Embodiment 3, a temperature measuring device 72 is provided at part of the fifth heat medium pipe 8e that is located between the second heat recovery heat exchanger 12 and the joining portion 31. The temperature measuring device 72 measures the temperature of the heat medium that flows through the fifth heat medium pipe 8e toward the joining portion 31 after passing through the second heat recovery heat exchanger 12. Also, the method for measuring the temperature of the heat medium that flows through the fourth heat medium pipe 8d toward the joining portion 31 is not particularly limited. In Embodiment 3, a temperature measuring device 71 is provided at the fourth heat medium pipe 8d. The temperature measuring device 71 measures the temperature of the heat medium that flows through the fourth heat medium pipe 8d toward the joining portion 31.
Specifically, for example, the second flow control unit 65 is controlled such that the temperature of the heat medium that flows into the fifth heat medium pipe 8e is lower than the temperature of the heat medium that flows into the fourth heat medium pipe 8d. For example, in the case where the second flow control unit 65 is controlled such that the heat medium that flows out from the use-side heat exchanger 3 configured to cool indoor air flows into the fifth heat medium pipe 8e and such that the heat medium that flows out from the use-side heat exchanger 3 configured to heat indoor air flows into the fourth heat medium pipe 8d, the flow passage of the flow switching device 45 of the second refrigerant circuit 9 is switched to a flow passage that causes the first heat recovery heat exchanger 11 to operate as an evaporator and the second heat recovery heat exchanger 12 to operate as a condenser. Then, for example, when the difference between the temperature measured by the temperature measuring device 72 and the temperature measured by the temperature measuring device 71 exceeds a predetermined temperature difference, the compressor 16 in the second refrigerant circuit 9 is started. In addition, when the difference between the temperature measured by the temperature measuring device 72 and the temperature measured by the temperature measuring device 71 falls to or below a predetermined temperature difference, in the second refrigerant circuit 9, the compressor 16 is stopped, or the rotation speed of the compressor 16 is reduced. In the second refrigerant circuit 9, the rotation speed of the compressor 16 may be changed such that the greater the difference between the temperature measured by the temperature measuring device 72 and the temperature measured by the temperature measuring device 71, the higher the rotation speed of the compressor 16.
In the heat medium circuit 8 of each of the refrigeration cycle apparatuses 200 according to Embodiments 1 to 3, the heat medium that flows out from the first load-side heat exchanger 1 and the heat medium that flows out from the second load-side heat exchanger 2 join together at the joining portion 31 to combine into a single heat medium. Then, in the heat medium circuit 8 of each of the refrigeration cycle apparatuses 200 according to Embodiments 1 to 3, at the branching portion 32, the above single heat medium branches into a heat medium that flows into the first load-side heat exchanger 1 and a heat medium that flows into the second load-side heat exchanger 2. Thus, in the refrigeration cycle apparatuses 200 according to Embodiments 1 and 2 that do not include the second refrigerant circuit 9, in the case where the cooling and heating mixed operation is performed, the difference between the temperature of the heat medium that flows into the first load-side heat exchanger 1 and the temperature of the heat medium that flows out from the first load-side heat exchanger 1 is greater than in a configuration in which the heat medium that flows out from the first load-side heat exchanger 1 does not join the heat medium that flows out from the second load-side heat exchanger 2 and returns to the first load-side heat exchanger 1. Similarly, in the refrigeration cycle apparatuses 200 according to Embodiments 1 and 2 that do not include the second refrigerant circuit 9, in the case where the cooling and heating mixed operation is performed, the difference between the temperature of the heat medium that flows into the second load-side heat exchanger 2 and the temperature of the heat medium that flows out from the second load-side heat exchanger 2 is greater than in the configuration in which the heat medium that flows out from the first load-side heat exchanger 1 does not join the heat medium that flows out from the second load-side heat exchanger 2 and returns to the first load-side heat exchanger 1. In such a manner, in the case where the difference between the temperature of the heat medium that flows into a load-side heat exchanger and the temperature of the heat medium that flows out from the load-side heat exchanger increases, the performance of the heat medium circuit 8 may be deteriorated.
By contrast, the refrigeration cycle apparatus 200 according to Embodiment 3 that includes the second refrigerant circuit 9 can reduce the difference between the temperature of the heat medium that flows into the first load-side heat exchanger 1 and the temperature of the heat medium that flows out from the first load-side heat exchanger 1, in the case where the cooling and heating mixed operation is performed, as compared with the refrigeration cycle apparatuses 200 according to Embodiments 1 and 2. In addition, the refrigeration cycle apparatus 200 according to Embodiment 3 including the second refrigerant circuit 9 can reduce the difference between the temperature of the heat medium that flows into the second load-side heat exchanger 2 and the temperature of the heat medium that flows out from the second load-side heat exchanger 2, in the case where the cooling and heating mixed operation is performed, as compared with the refrigeration cycle apparatuses 200 according to Embodiments 1 and 2. Therefore, in the refrigeration cycle apparatus 200 according to Embodiment 3 including the second refrigerant circuit 9, the performance of the heat medium circuit 8 at the time of performing the cooling and heating mixed operation is improved, as compared with the refrigeration cycle apparatuses 200 according to Embodiments 1 and 3. In other words, in the refrigeration cycle apparatus 200 according to Embodiment 3 including the second refrigerant circuit 9, the energy efficiency is improved, as compared with the refrigeration cycle apparatuses 200 according to Embodiments 1 and 2.
In the cooling and heating mixed operation of the refrigeration cycle apparatus 200, the cooling capacity and the heating capacity may differ from each other. In such a case, it is preferable that the refrigerant that flows out from one of the use-side heat exchangers 3 that performs an operation with a lower capacity flow into the fifth heat medium pipe 8e and the second heat recovery heat exchanger 12. With this configuration, it is possible to reduce the size of the second heat recovery heat exchanger 12 and that of the second refrigerant circuit 9. Accordingly, it is possible to improve the energy efficiency of the refrigeration cycle apparatus 200 while reducing an increase in the size of the refrigeration cycle apparatus 200.
In addition, in the refrigeration cycle apparatus 200 in which in the cooling and heating mixed operation or the dehumidifying operation, the heat-source-side heat exchanger 4 and the second load-side heat exchanger 2 are connected in series to the first load-side heat exchanger 1, because of provision of the second refrigerant circuit 9, it is possible to achieve the following advantage. Specifically, in the refrigeration cycle apparatus 200 configured in the above manner, a heat exchanger having a lower heat exchange capacity than the first load-side heat exchanger 1 is used as the second load-side heat exchanger 2. In this case, by operating the second refrigerant circuit 9 such that the second load-side heat exchanger 2 and the first heat recovery heat exchanger 11 of the second refrigerant circuit 9 fulfill the same function, the heat exchange capacity of the second load-side heat exchanger 2 can be supplemented by the first heat recovery heat exchanger 11.

Embodiment 4

A configuration in which the components of the heat medium circuit 8 are mounted in units is not limited to the examples descried regarding Embodiments 1 to 4. The components of the heat medium circuit 8 may be mounted in units as descried below regarding Embodiment 4. Regarding Embodiment 4, matters that are the same as those in any of Embodiments 1 to 3 will not particularly be described. In addition, regarding Embodiment 4, components that have the same functions as those in in any of Embodiments 1 to 3 will be denoted by the same reference signs.
Figs. 7 to 10 are refrigerant circuit diagrams illustrating examples of a refrigeration cycle apparatus according to Embodiment 4.
In the refrigeration cycle apparatus 200 according to Embodiment 4, part of the heat medium circuit 8 is mounted in the heat source unit 201, the use-side heat exchangers 3 are mounted in the heat load units 202, and part of the heat medium circuit 8 is mounted in the relay unit 203. Specifically, the first load-side heat exchanger 1, the second load-side heat exchanger 2, the pump 6, and the branching portion 32 are mounted in the heat source unit 201. The joining portion 31 is provided in the relay unit.
For example, regarding fluorocarbon-based refrigerant that is commonly used in a refrigerant circuit, it is hoped that the amount of fluorocarbon-based refrigerant to be filled in the refrigerant circuit will be reduced. In this case, by mounting the first refrigerant circuit 7 in the heat source unit 201, it is possible to reduce the length of the first refrigerant circuit 7 and reduce the amount of first refrigerant that is filled into the first refrigerant circuit 7. In this case, for example, in the case where components of the heat medium circuit 8 that are other than the first load-side heat exchanger 1 and the second load-side heat exchanger 2 are mounted in the relay unit 203, the number of heat medium pipes of the heat medium circuit 8 that connect the heat source unit 201 and the relay unit 203 is four. By contrast, by mounting the components of the heat medium circuit 8 in the heat source unit 201 and the relay unit 203 as in Embodiment 4, it is possible to reduce the number of heat medium pipes of the heat medium circuit 8 that connect the heat source unit 201 and the relay unit 203 to three. Therefore, by mounting the components of the heat medium circuit 8 in the heat source unit 201 and the relay unit 203 as in Embodiment 4, it is possible to reduce the space where the refrigeration cycle apparatus 200 is installed.
Regarding Embodiments 1 to 4, the refrigeration cycle apparatuses 200 are described above. However, the refrigeration cycle apparatuses 200 as described regarding Embodiments 1 to 4 are merely examples of the refrigeration cycle apparatus according to the present disclosure. For example, the refrigeration cycle apparatus according to the present disclosure may have a configuration that is obtained by combining a well-known technique or well-known techniques not described regarding any of Embodiments 1 to 4 with any of the refrigeration cycle apparatuses 200 described regarding any of Embodiments 1 to 4. In addition, for example, the refrigeration cycle apparatus according to the present disclosure may have a configuration that is obtained by omitting or modifying part of the configuration of any of the refrigeration cycle apparatuses 200 described regarding Embodiments 1 to 4 without departing from the gist of the present disclosure.

Reference Signs List

1: first load-side heat exchanger, 2: second load-side heat exchanger, 3: use-side heat exchanger, 4: heat-source-side heat exchanger, 5: fan, 6: pump, 7: first refrigerant circuit, 8: heat medium circuit, 8a: first heat medium pipe, 8b: second heat medium pipe, 8c: third heat medium pipe, 8d: fourth heat medium pipe, 8e: fifth heat medium pipe, 9: second refrigerant circuit, 11: first heat recovery heat exchanger, 12: second heat recovery heat exchanger, 14: compressor, 16: compressor, 17: expansion device, 18: expansion device, 20: expansion device, 21: first expansion device, 22: second expansion device, 31: joining portion, 32: branching portion, 33: joining portion, 34: branching portion, 41: flow switching device, 42: flow switching device, 43: flow switching device, 45: flow switching device, 51: opening and closing device, 52: opening and closing device, 53: opening and closing device, 54: opening and closing device, 60: first flow control unit, 61: flow control device, 62: flow control device, 65: second flow control unit, 66: flow control device, 67: flow control device, 71: temperature measuring device, 72: temperature measuring device, 200: refrigeration cycle apparatus, 201: heat source unit, 202: heat load unit, 203: relay unit, 210: controller

Claims

A refrigeration cycle apparatus comprising:
a heat medium circuit including a plurality of load-side heat exchangers and a plurality of use-side heat exchangers, the plurality of load-side heat exchangers being configured to cause heat exchange to be performed between first refrigerant and a heat medium different from the first refrigerant, the plurality of use-side heat exchangers being supplied with the heat medium supplied from at least one of the load-side heat exchangers, the heat medium circuit being a circuit in which the heat medium circulates,

wherein

the heat medium circuit further includes
a joining portion configured to cause the heat medium that flows out from a first use-side heat exchanger and the heat medium that flows out from a second use-side heat exchanger to join together,

a branching portion configured to cause a first heat medium pipe through which the heat medium that flows out from the joining portion flows to branch into a second heat medium pipe that is connected with a first load-side heat exchanger and a third heat medium pipe that is connected with a second load-side heat exchanger, the branching portion connecting the first load-side heat exchanger and the second load-side heat exchanger in parallel, and

a pump provided between the joining portion and the branching portion and configured to circulate the heat medium,

where the first load-side heat exchanger is one of the load-side heat exchangers,

the first use-side heat exchanger is one of the use-side heat exchangers, into which the heat medium supplied from the first load-side heat exchanger flows,

the second load-side heat exchanger is one of those of the load-side heat exchangers that are configured to supply the heat medium having a temperature different from a temperature of the heat medium that is supplied by the first load-side heat exchanger, and

the second use-side heat exchanger is one of those of the use-side heat exchangers, into which the heat medium supplied from the second load-side heat exchanger flows, the one of the use-side heat exchangers being other than the first use-side heat exchanger.
The refrigeration cycle apparatus of claim 1, further comprising a first refrigerant circuit in which the first refrigerant circulates, the first refrigerant circuit including the first load-side heat exchanger and the second load-side heat exchanger.
The refrigeration cycle apparatus of claim 2, wherein
the first refrigerant circuit further includes
a heat-source-side heat exchanger,

a first expansion device provided between the heat-source-side heat exchanger and the first load-side heat exchanger, and

a second expansion device provided between the first load-side heat exchanger and the second load-side heat exchanger, and

the first load-side heat exchanger and the second load-side heat exchanger are connected in series to the heat-source-side heat exchanger.
The refrigeration cycle apparatus of claim 2, wherein
the first refrigerant circuit further includes a heat-source-side heat exchanger, and

when the first load-side heat exchanger and the second load-side heat exchanger each operate as a radiator, and when the first load-side heat exchanger and the second load-side heat exchanger each operate as an evaporator, the first load-side heat exchanger and the second load-side heat exchanger are connected in parallel to the heat-source-side heat exchanger.
The refrigeration cycle apparatus of claim 2 or 4, wherein
the first refrigerant circuit further includes a heat-source-side heat exchanger, and

when the first load-side heat exchanger operates as one of a radiator and an evaporator, and when the heat-source-side heat exchanger and the second load-side heat exchanger each operate as an other of the radiator and the evaporator, the heat-source-side heat exchanger and the second load-side heat exchanger are connected in parallel to the first load-side heat exchanger.
The refrigeration cycle apparatus of any one of claims 1 to 5, wherein
a heat-medium inlet of the first use-side heat exchanger and a heat-medium inlet of the second use-side heat exchanger are connected with a heat-medium outlet of the first load-side heat exchanger and a heat-medium outlet of the second load-side heat exchanger, and

the heat medium circuit further includes first flow control units that are provided on a heat-medium inlet side of the first use-side heat exchanger and a heat-medium inlet side of the second use-side heat exchanger, the first flow control units being configured to adjust a flow rate of the heat medium supplied from the first load-side heat exchanger and a flow rate of the heat medium supplied from the second load-side heat exchanger.
The refrigeration cycle apparatus of any one of claims 1 to 6, further comprising a second refrigerant circuit in which second refrigerant circulates,
wherein
in the heat medium circuit, a heat-medium outlet of the first use-side heat exchanger and a heat-medium outlet of the second use-side heat exchanger are connected with a fourth heat medium pipe connected with the joining portion and a fifth heat medium pipe connected with the joining portion,

the heat medium circuit further includes second flow control units that are provided on a heat-medium outlet side of the first use-side heat exchanger and a heat-medium outlet side of the second use-side heat exchanger, the second flow control units being configured to adjust a flow rate of the heat medium that flows into the fourth heat medium pipe and a flow rate of the heat medium that flows into the fifth heat medium pipe,

the second refrigerant circuit includes
a first heat recovery heat exchanger provided between the second use-side heat exchanger and a heat-medium outlet of the second load-side heat exchanger, the first heat recovery heat exchanger being configured to cause heat exchange to be performed between the second refrigerant and the heat medium, and

a second heat recovery heat exchanger configured to cause heat exchange to be performed between the second refrigerant and the heat medium that flows through the fifth heat medium pipe, and

in the second refrigerant circuit, when one of the first heat recovery heat exchanger and the second heat recovery heat exchanger operates as a radiator, an other of the first heat recovery heat exchanger and the second heat recovery heat exchanger operates as an evaporator.
The refrigeration cycle apparatus of any one of claims 1 to 7, further comprising:
a heat source unit in which part of the heat medium circuit is mounted; and

a relay unit in which part of the heat medium circuit is mounted, the relay unit connecting the heat source unit and heat load units in which the use-side heat exchangers are mounted,

wherein

the first load-side heat exchanger, the second load-side heat exchanger, the pump, and the branching portion are mounted in the heat source unit, and

the joining portion is mounted in the relay unit.