Refrigeration cycle device

Abstract

A refrigeration circuit device according to one embodiment of the present invention comprises a heat source unit. The heat source unit includes a heat transfer medium heat exchanger. A refrigerant circulating in a refrigerant circuit and a heat transfer medium, which is a medium other than the refrigerant, exchange heat in the heat transfer medium heat exchanger. The heat source unit discharges the heat transfer medium, which has exchanged heat with the refrigerant in the heat transfer medium heat exchanger, to the outside of the heat source unit. The refrigeration circuit device includes a heat transfer medium circuit in which the heat transfer medium supplied by the heat source unit circulates.The heat transfer fluid circuit has several heat exchangers on the load side and a switching mechanism configured to change the distribution state of the heat transfer fluid, causing it to flow into and out of each of the heat exchangers on the load side. The refrigeration circuit also includes a distribution unit that houses the switching mechanism.

Description

Technical field

[0001] The present invention relates to a refrigeration circuit device. State of the art

[0002] To date, a refrigeration circuit device is known that incorporates a chiller-type heat source unit. The chiller-type heat source unit causes the refrigerant circulating within a refrigerant circuit and a heat transfer medium (a medium other than the refrigerant) to exchange heat in a heat transfer medium heat exchanger. The heat source unit then discharges the heat transfer medium, which has exchanged heat with the refrigerant in the heat transfer medium heat exchanger, to the outside of the heat source unit. In addition to the chiller-type heat source unit, the refrigeration circuit device also includes a heat transfer medium circuit in which the heat transfer medium supplied by the heat source unit circulates.

[0003] A refrigeration circuit device, including a chiller-type heat source unit, has also been proposed, featuring multiple heat exchangers on the load side within a heat transfer medium circuit. For example, patent literature 1 discloses that a refrigeration circuit device comprising a chiller-type heat source unit and multiple heat exchangers on the load side is used as an air conditioning device, as an example of its application. That is, the refrigeration circuit device disclosed in patent literature 1 utilizes the multiple heat exchangers on the load side as an indoor heat exchanger.

[0004] In a known refrigeration circuit device comprising a chiller-type heat source unit and several heat exchangers on the load side, a heat transfer fluid circuit is configured as follows. The heat transfer fluid circuit has a main line that allows heat transfer fluid flowing out of the heat source unit to pass through it and returns the heat transfer fluid to the heat source unit. Each of the heat exchangers on the load side is connected to the main line via a branch line.

[0005] The distribution state of the heat transfer medium, which flows into and out of each of the heat exchangers on the load side, is switched by a switching mechanism located in the branch line connected to the corresponding heat exchanger on the load side. That is, the switching mechanisms, each located in the branch line connected to the corresponding heat exchanger on the load side, each perform a switching operation to determine whether the heat transfer medium should be allowed to flow into and out of the corresponding heat exchanger on the load side. Bibliography Patent literature

[0006] Patent Literature 1: Japanese Unexamined Patent Application Publication JP H4 - 214 134 A Summary of the invention: Technical problem

[0007] When an installation of the type of known refrigeration circuit described above is carried out at the installation site, comprising a chiller-type heat source unit and several heat exchangers on the load side, the main line of the heat transfer medium circuit is positioned so that it passes close to each of the heat exchangers on the load side. Each of the heat exchangers on the load side is connected to a portion of the main line located near the heat exchanger on the load side via a branch line. Consequently, this type of known refrigeration circuit requires a long main line.

[0008] Additionally, the heat transfer fluids flowing through the individual heat exchangers on the load side combine and flow through the main line. To reduce the pressure losses caused by the heat transfer fluid flowing through the main line, the main line must be thick. This means that for the type of known refrigeration circuit described above, which has a chiller-type heat source unit and several heat exchangers on the load side, a long, thick main line must be installed at the installation site. Therefore, installing this type of known refrigeration circuit at the installation site takes time.

[0009] The present invention was designed to solve the problem described above. It is therefore an object of the invention to provide a refrigeration circuit device with a chiller-type heat source unit and several heat exchangers on the load side, which enables a reduction in installation time at the point of use compared to previous methods. Solution to the problem

[0010] A refrigeration circuit device according to one embodiment of the present invention comprises a heat source unit. The heat source unit includes a heat transfer medium heat exchanger. A refrigerant circulating in a refrigerant circuit and a heat transfer medium, which is a medium other than the refrigerant, exchange heat in the heat transfer medium heat exchanger. The heat source unit discharges the heat transfer medium, which has exchanged heat with the refrigerant in the heat transfer medium heat exchanger, to the outside of the heat source unit.

[0011] The refrigeration circuit includes a heat transfer fluid circuit in which the heat transfer fluid supplied by the heat source unit circulates. The heat transfer fluid circuit has multiple heat exchangers on the load side and a switching mechanism configured to change the distribution state of the heat transfer fluid, directing it into and out of each of the heat exchangers on the load side. The refrigeration circuit also includes a distribution unit that houses the switching mechanism. Advantageous effects of the invention

[0012] In the refrigeration circuit device according to one embodiment of the present invention, the line to be installed at the installation site, which is equivalent to the main line of a known refrigeration circuit device, is a line connecting a heat source unit and a distribution unit. Therefore, in the refrigeration circuit device according to one embodiment of the invention, the line to be installed at the installation site can be shorter than the main line of the known refrigeration circuit device. The installation time of the refrigeration circuit device at the installation site according to one embodiment of the invention can thus be reduced compared to the previous method. Brief description of the drawings Fig. Figure 1 is a diagram showing an example of the circuit configuration of a refrigeration circuit device according to embodiment 1, operating in a cooling-only mode. Fig. Figure 2 is a diagram showing a refrigerant flow and that of a heat transfer medium when the refrigeration circuit device according to embodiment 1 is operating in a main cooling mode. Fig. Figure 3 is a diagram showing a refrigerant flow and that of a heat transfer medium when the refrigeration circuit device according to embodiment 1 is operating in a heating-only mode. Fig. Figure 4 is a diagram showing a refrigerant flow and that of a heat transfer medium when the refrigeration circuit device according to embodiment 1 is operating in a heating main operating mode. Fig. Figure 5 is a diagram showing an example of the circuit configuration of a refrigeration circuit device according to embodiment 2. Fig. Figure 6 is a diagram showing an example of the circuit configuration of the refrigeration circuit device according to embodiment 2. Fig. Figure 7 is a diagram showing an example of the circuit configuration of a refrigeration circuit device according to embodiment 3. Fig. Figure 8 is a diagram showing an example of the circuit configuration of the refrigeration circuit device according to embodiment 3. Fig. Figure 9 is a diagram showing an example of the circuit configuration of a refrigeration circuit device according to embodiment 4. Fig. Figure 10 is a diagram showing an example of the circuit configuration of the refrigeration circuit device according to embodiment 4. Fig. Figure 11 is a diagram showing an example of the circuit configuration of a refrigeration circuit device according to embodiment 5. Description of embodiments

[0013] An example of a refrigeration circuit device according to an embodiment of the invention is described below with reference to the drawings and other details by illustrating embodiments 1 to 5. The drawings, including Fig. In 1, elements with the same reference numeral are identical or corresponding elements. This applies to the entire text in embodiments 1 through 5. The refrigeration circuit device according to an embodiment of the invention, described by illustrating embodiments 1 through 5, is merely an example. The refrigeration circuit device of an embodiment of the invention is not limited to the modes described in the description. In embodiments 1 through 5, the refrigeration circuit device of an embodiment of the invention is used as an application example in the context of an air conditioning device. Design 1

[0014] Fig. Figure 1 is a diagram showing an example of the circuit configuration of a refrigeration circuit device according to embodiment 1, operating in a cooling-only mode. The arrows with solid lines, whose heads are filled in black, indicate in Fig. Numbers 1 to 11 indicate the direction of a refrigerant flow. The arrows with dashed lines and black heads point in... Fig. Numbers 1 to 11 indicate the direction of flow of a heat transfer medium. Fig. Figures 1 to 11 show a flow path in the open state such that the corresponding valve or mechanism is filled with white, while a flow path in the closed state is shown such that the corresponding valve or mechanism is filled with black.

[0015] A refrigeration circuit device 200 has a chiller-type heat source unit 201 and a heat transfer medium circuit 110 in which a heat transfer medium circulates, supplied by the heat source unit 201.

[0016] The heat source unit 201 comprises a refrigerant circuit 100, in which refrigerant circulates, and a heat transfer medium heat exchanger. In other words, the refrigerant circuit 100 and the heat transfer medium heat exchanger are contained within the heat source unit 201. The heat transfer medium heat exchanger acts as a condenser or evaporator within the refrigerant circuit 100 and causes the refrigerant circulating in the circuit 100 and a heat transfer medium (a different medium than the refrigerant) to exchange heat. The heat source unit 201 then discharges the heat transfer medium, which has exchanged heat with the refrigerant in the heat transfer medium heat exchanger, to the outside of the unit.

[0017] The type of refrigerant to circulate in refrigerant circuit 100 is not limited to a specific type. In one example, the refrigerant to circulate in refrigerant circuit 100 is an olefin-based refrigerant, an ethylene-based refrigerant, an ethane-based refrigerant, propane, or dimethyl ether. In another example, the refrigerant to circulate in refrigerant circuit 100 is a blend of at least two of the following: an olefin-based refrigerant, an ethylene-based refrigerant, an ethane-based refrigerant, propane, and a dimethyl ether. The olefin-based refrigerant is, for example, tetrafluoropropene, such as HFO1234yf and HFO1234ze (E).

[0018] The ethylene-based refrigerant is, for example, difluoroethylene. The ethane-based refrigerant is, for example, tetrafluoroethane. The type of heat transfer medium that exchanges heat with the refrigerant in the heat transfer medium heat exchanger is also not limited to a specific type. Examples of heat transfer media include brine, antifreeze, and water. Brine contains, for example, a calcium chloride solution, a sodium chloride solution, a magnesium chloride solution, or ethylene glycol.

[0019] In embodiment 1, a first heat transfer medium heat exchanger 1 and a second heat transfer medium heat exchanger 2 are arranged as the heat transfer medium heat exchanger. The refrigeration circuit device 200 can also have only one of the first heat transfer medium heat exchanger 1 and the second heat transfer medium heat exchanger 2. That is, the refrigeration circuit device 200 can also have only a single heat transfer medium heat exchanger. In embodiment 1, the following applies: If one of the first heat transfer medium heat exchanger 1 and the second heat transfer medium heat exchanger 2 operates as a condenser, the other of the first heat transfer medium heat exchanger 1 and the second heat transfer medium heat exchanger 2 can operate as an evaporator. That is, the heat source unit 201 according to embodiment 1 can supply a heated heat transfer medium and a cooled heat transfer medium simultaneously.Because of this configuration, in embodiment 1 the refrigerant circuit 100 is configured as follows, for example.

[0020] The refrigerant circuit 100 comprises the following: a compressor 14, a first flow switching device 41, a second flow switching device 42, an outdoor heat exchanger 4, a first expansion device 21, a second expansion device 22, a first opening / closing valve 51, a second opening / closing valve 52, a third opening / closing valve 53, and a fourth opening / closing valve 54. The first heat transfer medium heat exchanger 1 and the second heat transfer medium heat exchanger 2 also form part of the refrigerant circuit 100.

[0021] Compressor 14 draws in refrigerant, compresses it to a high-temperature / high-pressure state, and discharges the resulting refrigerant. Compressor 14 can be, for example, a rotary compressor, a scroll compressor, a screw compressor, or a reciprocating compressor. The refrigerant outlet of compressor 14 is connected to the first flow switching device 41 and the second flow switching device 42. More precisely, a refrigerant line connected to the refrigerant outlet of compressor 14 branches at a junction and is divided into two refrigerant lines.

[0022] One of the split refrigerant lines is connected to the first flow switching device 41, while the other split refrigerant line is connected to the second flow switching device 42. The refrigerant intake inlet of the compressor 14 is also connected to both the first flow switching device 41 and the second flow switching device 42. More precisely: The refrigerant line connected to the refrigerant intake inlet of the compressor 14 branches and is divided into two refrigerant lines. One of the split refrigerant lines is connected to the first flow switching device 41, while the other split refrigerant line is connected to the second flow switching device 42.

[0023] The first flow switching device 41 is, for example, a four-way valve. The first flow switching device 41 switches a current with respect to whether the refrigerant outlet of the compressor 14 is allowed to communicate with the outdoor heat exchanger 4. The first flow switching device 41 also switches a current with respect to whether the refrigerant intake inlet of the compressor 14 is allowed to communicate with the outdoor heat exchanger 4. The second flow switching device 42 is, for example, a four-way valve.

[0024] The second flow switching device 42 switches a current to determine whether the refrigerant outlet of the compressor 14 is allowed to communicate with the third open / close valve 53 and the fourth open / close valve 54. The first flow switching device 41 switches a current to determine whether the refrigerant intake inlet of the compressor 14 is allowed to communicate with the third open / close valve 53 and the fourth open / close valve 54.

[0025] The outdoor heat exchanger 4 functions as either an evaporator or a condenser. When the outdoor heat exchanger 4 functions as an evaporator, it performs a heat exchange between the refrigerant and the outside air flowing inside, causing the refrigerant to evaporate and become gaseous. When the outdoor heat exchanger 4 functions as a condenser, it performs a heat exchange between the refrigerant and the outside air flowing inside, causing the refrigerant to condense and become liquid.

[0026] In embodiment 1, to improve the heat exchange between the refrigerant and the outside air in the outside heat exchanger 4, an outside fan 5, which supplies outside air to the outside heat exchanger 4, is arranged adjacent to the outside heat exchanger 4. The outside fan 5 can be, for example, a propeller fan, a line-flow fan (registered trademark), or a multi-blade centrifugal fan, based on the operating conditions, such as the volume flow rate and the static pressure of the outside air to be supplied to the outside heat exchanger 4.

[0027] Each of the first expansion device 21 and the second expansion device 22 functions as a reducing valve or an expansion valve and is used to expand the refrigerant, thus reducing its pressure. Each of the first expansion device 21 and the second expansion device 22 is, for example, an electronic expansion valve capable of controlling the refrigerant flow rate. The first expansion device 21 and the second expansion device 22 are connected in parallel to the outdoor heat exchanger 4. More precisely, the refrigerant line connected to the outdoor heat exchanger 4 branches at junction b and is divided into two refrigerant lines.

[0028] One of the split refrigerant lines is connected to the first expansion device 21, while the other split refrigerant line is connected to the second expansion device 22. The first expansion device 21 and the second expansion device 22 are not limited to an electronic expansion valve and can also be a mechanical expansion valve that uses a diaphragm for the pressure-receiving part. The first expansion device 21 and the second expansion device 22 can, for example, be partially formed by a capillary tube.

[0029] As discussed above, the first heat transfer medium heat exchanger 1 and the second heat transfer medium heat exchanger 2 each function as a condenser or an evaporator in the refrigerant circuit 100. When the first heat transfer medium heat exchanger 1 and the second heat transfer medium heat exchanger 2 operate as evaporators, they perform a heat exchange between the refrigerant and a heat transfer medium flowing inside, causing the refrigerant to evaporate and enter a gaseous state. In this case, the heat transfer medium is cooled by the refrigerant.

[0030] When the first heat transfer medium heat exchanger 1 and the second heat transfer medium heat exchanger 2 operate as condensers, they perform a heat exchange between the refrigerant and a heat transfer medium flowing inside, causing the refrigerant to condense and liquefy. In this case, the heat transfer medium is heated by the refrigerant. One end of the refrigerant flow path of the first heat transfer medium heat exchanger 1 is connected to the first expansion device 21. One end of the refrigerant flow path of the second heat transfer medium heat exchanger 2 is connected to the second expansion device 22.

[0031] Each of the first open / close valve 51, the second open / close valve 52, the third open / close valve 53, and the fourth open / close valve 54, for example, is a two-way valve and opens and closes the flow path where the corresponding open / close valve is installed. The first open / close valve 51 and the third open / close valve 53 are connected in parallel to the other end of the refrigerant flow path of the first heat transfer medium heat exchanger 1. The second open / close valve 52 and the fourth open / close valve 54 are connected in parallel to the other end of the refrigerant flow path of the second heat transfer medium heat exchanger 2. The first opening / closing valve 51 and the second opening / closing valve 52 are connected at a node c by a line that connects the refrigerant intake inlet of the compressor 14 and the first flow switching device 41.The third opening / closing valve 53 and the fourth opening / closing valve 54 are connected to the second flow switching device 42.

[0032] As mentioned above, the heat transfer medium circuit 110 is a circuit in which a heat transfer medium circulates, supplied by the heat source unit 201. That is, the heat transfer medium circuit 110 is a circuit in which a heat transfer medium circulates that has exchanged heat with the refrigerant in the heat transfer medium heat exchanger. The heat transfer medium circuit 110 has several heat exchangers on the load side and a switching mechanism 70. The switching mechanism 70 changes the distribution state of a heat transfer medium so that it flows into and out of each of the heat exchangers on the load side. In embodiment 1, the heat transfer medium circuit 110 has heat exchangers 3a and 3b on the load side as the multiple heat exchangers on the load side.

[0033] The switching mechanism 70 therefore switches the distribution state of a heat transfer medium so that it flows into and out of each of the heat exchangers 3a and 3b on the load side. As mentioned above, the refrigeration circuit device 200 according to embodiment 1 is used as an air conditioning device. The heat exchangers 3a and 3b on the load side are therefore used as an indoor heat exchanger that heats or cools indoor air. The heat exchangers 3a and 3b on the load side are housed in different heat load units 202 and installed in the indoor space, which is the room to be air-conditioned.

[0034] The use of the refrigeration circuit device 200 as an air conditioning unit is merely one application example. The refrigeration circuit device 200 can also be used as a device other than an air conditioning unit. For example, the heat exchangers 3a and 3b on the load side can be installed under the floor and used as underfloor heating. In another example, the heat exchangers 3a and 3b on the load side can be used to heat water stored in a hot water storage tank. In yet another example, the heat exchangers 3a and 3b on the load side can be used to cool the air inside a freezer.

[0035] As discussed above, in embodiment 1, the heat source unit 201 comprises the first heat transfer medium heat exchanger 1 and the second heat transfer medium heat exchanger 2. The heat transfer medium circuit 110 in embodiment 1 therefore has a first circuit 111, which allows a heat transfer medium to flow through it into the first heat transfer medium heat exchanger 1, and a second circuit 112, which allows a heat transfer medium to flow through it into the second heat transfer medium heat exchanger 2. The switching mechanism 70 reverses the distribution state of a heat transfer medium flowing from the first heat transfer medium heat exchanger 1, so that it flows into each of the heat exchangers on the load side.The switching mechanism 70 also switches the distribution state of a heat transfer medium flowing from the second heat transfer medium heat exchanger 2, so that it flows into each of the heat exchangers on the load side.

[0036] The switching mechanism 70 is explained in more detail: The switching mechanism 70 has a first flow switching mechanism 71, a second flow switching mechanism 72, a third flow switching mechanism 73, and a fourth flow switching mechanism 74. Each of the first flow switching mechanism 71, the second flow switching mechanism 72, the third flow switching mechanism 73, and the fourth flow switching mechanism 74 is, for example, a three-way valve. However, they are not limited to a three-way valve and can be formed by a combination of several two-way valves.

[0037] The first flow switching mechanism 71 is connected to the heat transfer medium flow outlet of the first heat transfer medium heat exchanger 1. The first flow switching mechanism 71 is also connected to the inlet of heat exchanger 3a on the load side. The first flow switching mechanism 71 is also connected to a line that connects the third flow switching mechanism 73 and heat exchanger 3b on the load side. The first flow switching mechanism 71 allows two of the three connection points to communicate with the first flow switching mechanism 71.

[0038] The second flow switching mechanism 72 is connected to the heat transfer medium flow inlet of the first heat transfer medium heat exchanger 1. A first pump 6, which will be discussed later, is installed between the second flow switching mechanism 72 and the heat transfer medium flow inlet of the first heat transfer medium heat exchanger 1. It can therefore be said that the second flow switching mechanism 72 is connected to the first pump 6. The second flow switching mechanism 72 is also connected to the outlet of heat exchanger 3a on the load side. The second flow switching mechanism 72 is also connected to a line that connects the fourth flow switching mechanism 74 and heat exchanger 3b on the load side. The second flow switching mechanism 72 allows two of the three connection points to communicate with the second flow switching mechanism 72.

[0039] The third flow switching mechanism 73 is connected to the heat transfer medium flow outlet of the second heat transfer medium heat exchanger 2. The third flow switching mechanism 73 is also connected to a line that connects the first flow switching mechanism 71 and the heat exchanger 3a on the load side. The third flow switching mechanism 73 is also connected to the inlet of the heat exchanger 3b on the load side. The third flow switching mechanism 73 allows communication between two of the three connection points.

[0040] The fourth flow switching mechanism 74 is connected to the heat transfer medium flow inlet of the second heat transfer medium heat exchanger 2. A second pump 7, which will be discussed later, is installed between the fourth flow switching mechanism 74 and the heat transfer medium flow inlet of the second heat transfer medium heat exchanger 2. It can therefore be said that the fourth flow switching mechanism 74 is connected to the second pump 7. The fourth flow switching mechanism 74 is also connected to a line that links the second flow switching mechanism 72 and the heat exchanger 3a on the load side. The fourth flow switching mechanism 74 is also connected to the outlet of the heat exchanger 3b on the load side. The fourth flow switching mechanism 74 allows two of the three connection points to communicate with the fourth flow switching mechanism 74.

[0041] The heat exchanger 3a on the load side becomes part of the first circuit 111 when it communicates with the first heat transfer medium heat exchanger 1. The flow switching mechanism that allows the first heat transfer medium heat exchanger 1 and the heat exchanger 3a on the load side to communicate with each other, located under the first flow switching mechanism 71, the second flow switching mechanism 72, the third flow switching mechanism 73, and the fourth flow switching mechanism 74, also becomes part of the first circuit 111. The line that allows the first heat transfer medium heat exchanger 1 and the heat exchanger 3a on the load side to communicate with each other also becomes part of the first circuit 111.

[0042] The heat exchanger 3a on the load side becomes part of the second circuit 112 when it communicates with the second heat transfer medium heat exchanger 2. The flow switching mechanism that allows the second heat transfer medium heat exchanger 2 and the heat exchanger 3a on the load side to communicate with each other, located under the first flow switching mechanism 71, the second flow switching mechanism 72, the third flow switching mechanism 73, and the fourth flow switching mechanism 74, also becomes part of the second circuit 112. The line that allows the second heat transfer medium heat exchanger 2 and the heat exchanger 3a on the load side to communicate with each other also becomes part of the second circuit 112.

[0043] The heat exchanger 3b on the load side similarly becomes part of the first circuit 111 when it communicates with the first heat transfer medium heat exchanger 1. The flow switching mechanism that allows the first heat transfer medium heat exchanger 1 and the heat exchanger 3b on the load side to communicate with each other also becomes part of the first circuit 111 under the first flow switching mechanism 71, the second flow switching mechanism 72, the third flow switching mechanism 73, and the fourth flow switching mechanism 74. The line that allows the first heat transfer medium heat exchanger 1 and the heat exchanger 3b on the load side to communicate with each other also becomes part of the first circuit 111. The heat exchanger 3b on the load side becomes part of the second circuit 112 when it communicates with the second heat transfer medium heat exchanger 2.

[0044] The flow switching mechanism that allows the second heat transfer medium heat exchanger 2 and the heat exchanger 3b on the load side to communicate with each other is located under the first flow switching mechanism 71, the second flow switching mechanism 72, the third flow switching mechanism 73, and the fourth flow switching mechanism 74. This flow switching mechanism also forms part of the second circuit 112. The line that allows the second heat transfer medium heat exchanger 2 and the heat exchanger 3b on the load side to communicate with each other also forms part of the second circuit 112.

[0045] The refrigeration circuit device 200 includes a relay unit 203. The switching mechanism 70 described above is incorporated in the relay unit 203. In other words, the refrigeration circuit device 200 includes the relay unit 203, in which the switching mechanism 70 is incorporated.

[0046] In embodiment 1, the heat transfer medium circuit 110 includes a pump that circulates the heat transfer medium within the circuit. More precisely, the heat transfer medium circuit 110 includes a first pump 6, located in the first circuit 111, and a second pump 7, located in the second circuit 112. The first pump 6 is positioned in the first circuit 111 where a heat transfer medium flows, destined to return to the first heat transfer medium heat exchanger 1. The first pump 6 discharges the heat transfer medium, allowing it to return to the first heat transfer medium heat exchanger 1. The second pump 7 is positioned in the second circuit 112 where a heat transfer medium flows, destined to return to the second heat transfer medium heat exchanger 2. The second pump 7 releases the heat transfer medium, so that it returns to the second heat transfer medium heat exchanger 2.In embodiment 1, the first pump 6 and the second pump 7 are included in the forwarding unit 203.

[0047] The refrigeration circuit device 200 according to embodiment 1 has a controller 210 that controls the operating state of the refrigeration circuit device 200. More precisely: The controller 210 starts and stops the compressor 14. The controller 210 can also control the speed of the compressor 14 when it is operating. This allows the amount of refrigerant to be discharged from the compressor 14 to be adjusted. The controller 210 also switches the flow path of each of the first flow switching device 41 and the second flow switching device 42. The controller 210 also starts and stops the outdoor fan 5.

[0048] The controller 210 can control the speed of the outdoor fan 5 when it is operating. The controller 210 also controls the opening degree of each of the first expansion device 21 and the second expansion device 22. The controller 210 also controls the open / closed state of each of the first open / close valve 51, the second open / close valve 52, the third open / close valve 53, and the fourth open / close valve 54. The controller 210 also switches the flow path of the changeover mechanism 70. That is, the controller 210 switches the flow path of each of the first flow changeover mechanism 71, the second flow changeover mechanism 72, the third flow changeover mechanism 73, and the fourth flow changeover mechanism 74. The controller 210 also starts and stops the first pump 6 and the second pump 7.The controller 210 can also control the speed of each of the first pump 6 and the second pump 7 when they are operating. This allows the amount of refrigerant to be discharged from the first pump 6 and that from the second pump 7 to be set.

[0049] The Controller 210, configured as described above, consists of dedicated hardware or a CPU (central processing unit) that executes a program stored in memory. The CPU can also be referred to as a central processing unit, processing unit, arithmetic unit, microprocessor, microcomputer, or processor.

[0050] If the controller 210 is implemented using dedicated hardware, it could be, for example, a single circuit, a composite circuit, an ASIC (application-specific integrated circuit), an FPGA (field-programmable gate array), or a combination thereof. The individual functional units to be implemented by the controller 210 can be implemented by individual hardware units or by a single hardware unit.

[0051] If the controller 210 is implemented by a CPU, the individual functions to be performed by the controller 210 are implemented by software, firmware, or a combination of these. The software and firmware are described as a program, and the program is stored in memory. The CPU reads the program stored in memory and executes it, thus implementing the individual functions of the controller 210. The memory is a volatile or non-volatile semiconductor memory, such as RAM, ROM, flash memory, EPROM, or EEPROM.

[0052] Some of the functions of the controller 210 can be implemented by dedicated hardware, and some of the functions can be implemented by software or firmware. In embodiment 1, the controller 210 is included in the heat source unit 201. However, at least part of the controller 210 can also be included in a location different from the heat source unit 201. For example, the configuration of the controller 210 can be distributed across and included in the heat source unit 201 and the distribution unit 203.

[0053] A refrigeration circuit has been proposed to date that includes a chiller-type heat source unit and several heat exchangers on the load side. In such a known refrigeration circuit, the heat transfer medium circuit is configured as follows. The heat transfer medium circuit has a main line that allows the heat transfer medium flowing out of the heat source unit to pass through it and returns the heat transfer medium to the heat source unit. Each of the heat exchangers on the load side is connected to the main line via a branch line.

[0054] The distribution state of the heat transfer medium, which flows into and out of each of the heat exchangers on the load side, is switched by a switching mechanism located in the branch line connected to the corresponding heat exchanger on the load side. That is, the switching mechanisms, each located in the branch line connected to the corresponding heat exchanger on the load side, each perform a switching operation to determine whether the heat transfer medium is allowed to flow into or out of the corresponding heat exchanger on the load side.

[0055] With the configuration described above, the following applies: When an installation of the type of known refrigeration circuit device described above is carried out at the installation site, comprising a chiller-type heat source unit and several heat exchangers on the load side, the main line of the heat transfer medium circuit is positioned so that it passes near each of the heat exchangers on the load side. Each of the heat exchangers on the load side is connected to a portion of the main line located near the heat exchanger on the load side via the corresponding branch line. Consequently, this type of known refrigeration circuit device requires a long main line. Additionally, the heat transfer media flowing through the individual heat exchangers on the load side combine and flow through the main line.To reduce the pressure losses caused by the flow of the heat transfer medium through the main line, the main line must be thick. This means that for the type of refrigeration circuit described above, a long, thick main line must be installed at the installation site.

[0056] Therefore, installing the type of refrigeration circuit described above at the installation site takes time. It is also necessary to individually install the switching mechanisms at the installation site on the branch lines connected to the corresponding heat exchangers on the load side. This process also makes the installation of the refrigeration circuit time-consuming. Since the heat transfer medium circuit of the type of refrigeration circuit described above has a long, thick main line, it also takes time to purge or expel the air from the heat transfer medium circuit when a heat transfer medium is introduced into it. This process also makes the installation of the refrigeration circuit time-consuming.The heat transfer medium circuit of the type described above, with a known refrigeration circuit device, has a long, thick main line, and consequently a large amount of heat transfer medium is needed to be absorbed in the heat transfer medium circuit.

[0057] In contrast, the on-site installation of the refrigeration circuit device 200 according to embodiment 1 is carried out as follows. The heat source unit 201, the distribution unit 203, and the heat load units 202 are installed at predetermined locations. Then, the heat source unit 201 and the distribution unit 203 are connected to each other by a line, and the distribution unit 203 and the heat load units 202 are connected to each other by a line. In the refrigeration circuit device 200 according to embodiment 1, the line that is equivalent to the main line of the heat transfer medium circuit of the known refrigeration circuit device is the line that connects the heat transfer medium heat exchanger and the switching mechanism 70.

[0058] This means that the line connecting the heat source unit 201 and the distribution unit 203 in the refrigeration circuit device 200 in embodiment 1 is part of the line equivalent to the main line of the known refrigeration circuit device. The remaining part of the line equivalent to the main line of the known refrigeration circuit device is incorporated into the heat source unit 201 and the distribution unit 203 in the refrigeration circuit device 200 according to embodiment 1. This means that when the heat source unit 201 and the distribution unit 203 are installed, the installation of the remaining part of the line equivalent to the main line of the known refrigeration circuit device is completed simultaneously.

[0059] In the refrigeration circuit device 200 according to embodiment 1, the line to be installed at the installation site, which is equivalent to the main line of the known refrigeration circuit device, can therefore be made shorter than the main line of the heat transfer medium circuit of the known refrigeration circuit device. Therefore, the installation time of the refrigeration circuit device 200 at the installation site according to embodiment 1 can be reduced compared to the previous version. Furthermore, in the refrigeration circuit device 200 according to embodiment 1, when the transfer unit 203 is installed, the installation of the switching mechanism 70 is also completed. In this respect as well, the installation time of the refrigeration circuit device 200 at the installation site according to embodiment 1 can be reduced compared to the previous version.

[0060] In the refrigeration circuit device 200 according to embodiment 1, the distribution unit 203 and the heat load units 202 are connected to each other by a line, and the line can therefore be made shorter, equivalent to the main line of the known refrigeration circuit device. In the refrigeration circuit device 200 according to embodiment 1, the following applies: Since the line can be reduced in length, equivalent to the main line of the known refrigeration circuit device, the occurrence of pressure losses generated by a heat transfer medium flowing through the line can be reduced. This also makes it possible to make the size of the line in the refrigeration circuit device 200 according to embodiment 1 smaller than the main line of the known refrigeration circuit device.

[0061] Consequently, the time required to purge or expel air from the heat transfer medium circuit 110 when a heat transfer medium is added to the circuit can be shorter than before. In this respect as well, the installation time of the refrigeration circuit device at the installation site 200 according to embodiment 1 can be reduced compared to the previous version. Regarding the refrigeration circuit device 200 according to embodiment 1, the following applies: Since the line can be made shorter and smaller, equivalent to the main line of the known refrigeration circuit device, the amount of heat transfer medium added to the circuit 110 can also be reduced compared to the previous version.

[0062] The operation of the refrigeration circuit device 200 is described below with reference to a refrigerant flow and that of a heat transfer medium. The refrigeration circuit device 200 can be operated in cooling-only mode, heating-only mode, cooling-primary mode, and heating-primary mode. Cooling-only mode is an operating mode in which all heat load units 202 perform cooling operations. Heating-only mode is an operating mode in which all heat load units 202 perform heating operations. Cooling-primary mode is an operating mode in which some heat load units 202 perform cooling operations, some perform heating operations, and the cooling load is higher than the heating load.The heating main operating mode is an operating mode in which some heat load units 202 perform cooling operation and some heat load units 202 perform heating operation and the heating load is higher than the cooling load. Cooling-only operating mode

[0063] Initially, this is based on Fig. 1. An explanation of the cooling-only operating mode, performed by the refrigeration circuit device 200. The cooling-only operating mode is described below with reference to Fig. 1 described, namely by illustrating an example in which all heat load units 202 perform cooling operation. In other words: Fig. Figure 1 illustrates an example in which a cooling energy load is generated in both heat exchangers 3a and 3b on the load side.

[0064] In cooling-only operating mode, the controller 210 switches the flow path of the first flow switching device 41 so that the refrigerant outlet of the compressor 14 communicates with the outdoor heat exchanger 4. The controller 210 also switches the flow path of the second flow switching device 42 so that the refrigerant intake inlet of the compressor 14 communicates with the third open / close valve 53 and the fourth open / close valve 54. The controller 210 also sets the first open / close valve 51 and the second open / close valve 52 to the open position and sets the third open / close valve 53 and the fourth open / close valve 54 to the closed position.

[0065] The controller 210 also switches the flow path of the first flow switching mechanism 71 so that the heat transfer medium flow outlet of the first heat transfer medium heat exchanger 1 and the heat exchanger 3a on the load side communicate with each other. The controller 210 also switches the flow path of the second flow switching mechanism 72 so that the heat transfer medium flow inlet of the first heat transfer medium heat exchanger 1 and the heat exchanger 3a on the load side communicate with each other.

[0066] The controller 210 also switches the flow path of the third flow switching mechanism 73 so that the heat transfer medium flow outlet of the second heat transfer medium heat exchanger 2 and the heat exchanger 3b on the load side communicate with each other. The controller 210 also switches the flow path of the fourth flow switching mechanism 74 so that the heat transfer medium flow inlet of the second heat transfer medium heat exchanger 2 and the heat exchanger 3b on the load side communicate with each other. The controller 210 also starts the compressor 14, the first pump 6, the second pump 7, and the outdoor fan 5.

[0067] When compressor 14 is operating, the refrigerant flows through refrigerant circuit 100 as follows. Compressor 14 compresses low-temperature, low-pressure refrigerant and releases it as a gaseous, high-temperature, high-pressure refrigerant. The gaseous, high-temperature, high-pressure refrigerant released from compressor 14 flows into the outdoor heat exchanger 4, which acts as a condenser, via node a and the first flow changeover device 41. The gaseous, high-temperature, high-pressure refrigerant is then transformed into a liquid, high-pressure refrigerant while transferring heat to the outdoor air. The liquid, high-pressure refrigerant flowing from the outdoor heat exchanger 4 branches at node b and flows into the first expansion device 21 and the second expansion device 22.

[0068] The liquid high-pressure refrigerant flowing into the first expansion device 21 is then expanded into a two-phase, low-temperature, low-pressure gas-liquid refrigerant and flows into the first heat transfer medium heat exchanger 1, which acts as an evaporator. The two-phase, low-temperature, low-pressure gas-liquid refrigerant flowing into the first heat transfer medium heat exchanger 1 then absorbs heat from a heat transfer medium and is transformed into gaseous, low-pressure refrigerant while cooling the heat transfer medium.

[0069] Similarly, the liquid high-pressure refrigerant flowing into the second expansion device 22 expands into a two-phase, low-temperature, low-pressure gas-liquid refrigerant and flows into the second heat transfer medium heat exchanger 2, which acts as an evaporator. The two-phase, low-temperature, low-pressure gas-liquid refrigerant flowing into the second heat transfer medium heat exchanger 2 then absorbs heat from a heat transfer medium and is transformed into a gaseous, low-pressure refrigerant while cooling the heat transfer medium.

[0070] The gaseous low-pressure refrigerant flowing from the first heat transfer medium heat exchanger 1 passes through the first opening / closing valve 51. The gaseous low-pressure refrigerant flowing from the second heat transfer medium heat exchanger 2 passes through the second opening / closing valve 52. These low-pressure gaseous refrigerants pass through node c and are drawn back into the compressor 14.

[0071] When the first pump 6 and the second pump 7 are operating, the heat transfer medium flows through the heat transfer medium circuit 110 as follows. The heat transfer medium discharged from the first pump 6 flows into the heat source unit 201 and enters the first heat transfer medium heat exchanger 1. The heat transfer medium is then cooled by the refrigerant and flows out of the first heat transfer medium heat exchanger 1. The heat transfer medium then flows into the distribution unit 203 and passes through the first flow switching mechanism 71. The heat transfer medium then flows into the heat load unit 202 and enters the heat exchanger 3a on the load side. The heat transfer medium then absorbs heat from the interior air and cools it. The heat transfer medium flowing from the heat exchanger 3a on the load side flows into the transfer unit 203 and passes through the second flow switching mechanism 72. The heat transfer medium is then drawn back into the first pump 6.

[0072] The heat transfer medium discharged from the second pump 7 flows into the heat source unit 201 and enters the second heat transfer medium heat exchanger 2. The heat transfer medium is then cooled by the refrigerant and flows out of the second heat transfer medium heat exchanger 2. The heat transfer medium then flows into the distribution unit 203 and passes through the third flow switching mechanism 73. The heat transfer medium then flows into the heat load unit 202 and enters the heat exchanger 3b on the load side. The heat transfer medium then absorbs heat from the interior air and cools it. The heat transfer medium flowing out of the heat exchanger 3b on the load side flows into the distribution unit 203 and passes through the fourth flow switching mechanism 74. The heat transfer medium is then drawn back into the second pump 7.

[0073] While the refrigeration circuit device 200 operates in cooling-only mode, the cycle described above is repeated in the refrigerant circuit 100 and in the heat transfer medium circuit 110. Cooling main operating mode

[0074] Fig. Figure 2 is a diagram showing the refrigerant flow and the flow of a heat transfer medium when the refrigeration circuit device according to embodiment 1 is operating in the main cooling mode. The main cooling mode is described below with reference to Fig. 2. This is described by illustrating an example in which the heat load unit 202, which accommodates the heat exchanger 3a on the load side, performs the cooling operation, and the heat load unit 202, which accommodates the heat exchanger 3b on the load side, performs the heating operation. In other words: Fig. Figure 2 illustrates an example in which a cooling energy load is generated in heat exchanger 3a on the load side and a heating energy load is generated in heat exchanger 3b on the load side.

[0075] In the main cooling operating mode, the controller 210 switches the flow path of the first flow switching device 41 so that the refrigerant outlet of the compressor 14 communicates with the outdoor heat exchanger 4. The controller 210 also switches the flow path of the second flow switching device 42 so that the refrigerant outlet of the compressor 14 communicates with the third open / close valve 53 and the fourth open / close valve 54. The controller 210 also sets the first open / close valve 51 and the fourth open / close valve 54 to the open state and sets the second open / close valve 52 and the third open / close valve 53 to the closed state.

[0076] The controller 210 also switches the flow path of the first flow switching mechanism 71 so that the heat transfer medium flow outlet of the first heat transfer medium heat exchanger 1 and the heat exchanger 3a on the load side communicate with each other. The controller 210 also switches the flow path of the second flow switching mechanism 72 so that the heat transfer medium flow inlet of the first heat transfer medium heat exchanger 1 and the heat exchanger 3a on the load side communicate with each other.

[0077] The controller 210 also switches the flow path of the third flow switching mechanism 73 so that the heat transfer medium flow outlet of the second heat transfer medium heat exchanger 2 and the heat exchanger 3b on the load side communicate with each other. The controller 210 also switches the flow path of the fourth flow switching mechanism 74 so that the heat transfer medium flow inlet of the second heat transfer medium heat exchanger 2 and the heat exchanger 3b on the load side communicate with each other. The controller 210 also starts the compressor 14, the first pump 6, the second pump 7, and the outdoor fan 5.

[0078] When compressor 14 is operated, the refrigerant flows through refrigerant circuit 100 as follows. Compressor 14 compresses low-temperature, low-pressure refrigerant and releases it as gaseous, high-temperature, high-pressure refrigerant. The gaseous, high-temperature, high-pressure refrigerant released from compressor 14 branches at node a and is divided into refrigerant that flows into the outdoor heat exchanger 4 via the first flow switching device 41, and refrigerant that flows into the second flow switching device 42.

[0079] The gaseous high-temperature, high-pressure refrigerant flowing into the outdoor heat exchanger 4, which acts as a condenser, is transformed into liquid high-pressure refrigerant while transferring heat to the outdoor air. The gaseous high-temperature, high-pressure refrigerant flowing into the second flow switching device 42 passes through the fourth open / close valve 54 and enters the second heat transfer medium heat exchanger 2, which also acts as a condenser. The gaseous high-temperature, high-pressure refrigerant entering the second heat transfer medium heat exchanger 2 transfers heat to the heat transfer medium and is transformed into liquid high-pressure refrigerant or two-phase high-pressure gas-liquid refrigerant while heating the heat transfer medium.

[0080] The refrigerant flowing out of the outdoor heat exchanger 4 flows towards node b. The refrigerant flowing out of the second heat transfer medium heat exchanger 2 passes through the second expansion unit 22 and also flows towards node b. These refrigerants combine at node b, and the combined refrigerant flows into the first expansion unit 21. The refrigerant flowing into the first expansion unit 21 is then expanded to a two-phase, low-temperature, low-pressure gas-liquid refrigerant and flows into the first heat transfer medium heat exchanger 1, which acts as an evaporator.

[0081] The two-phase, low-temperature, low-pressure gas-liquid refrigerant then absorbs heat from a heat transfer medium and is transformed into gaseous, low-pressure refrigerant while cooling the heat transfer medium. The gaseous, low-pressure refrigerant flowing from the first heat transfer medium heat exchanger 1 passes through the first open / close valve 51 and is drawn back into the compressor 14 via node c.

[0082] When the first pump 6 and the second pump 7 are operating, the heat transfer medium flows through the heat transfer medium circuit 110 as follows. The heat transfer medium discharged from the first pump 6 flows into the heat source unit 201 and enters the first heat transfer medium heat exchanger 1. The heat transfer medium is then cooled by the refrigerant and flows out of the first heat transfer medium heat exchanger 1. The heat transfer medium then flows into the distribution unit 203 and passes through the first flow switching mechanism 71. The heat transfer medium then flows into the heat load unit 202 and enters the heat exchanger 3a on the load side. The heat transfer medium then absorbs heat from the interior air and cools it. The heat transfer medium flowing from the heat exchanger 3a on the load side flows into the transfer unit 203 and passes through the second flow switching mechanism 72. The heat transfer medium is then drawn back into the first pump 6.

[0083] The heat transfer medium discharged from the second pump 7 flows into the heat source unit 201 and enters the second heat transfer medium heat exchanger 2. The heat transfer medium is then heated by the refrigerant and flows out of the second heat transfer medium heat exchanger 2. The heat transfer medium then flows into the distribution unit 203 and passes through the third flow switching mechanism 73. The heat transfer medium then flows into the heat load unit 202 and enters the heat exchanger 3b on the load side. The heat transfer medium then transfers heat to the interior air, warming it. The heat transfer medium flowing out of the heat exchanger 3b on the load side flows into the distribution unit 203 and passes through the fourth flow switching mechanism 74. The heat transfer medium is then drawn back into the second pump 7.

[0084] While the refrigeration circuit device 200 is operating in the main cooling mode, the cycle described above is repeated in the refrigerant circuit 100 and in the heat transfer medium circuit 110. Heat-only operating mode

[0085] Fig. Figure 3 is a diagram showing the refrigerant flow and the flow of a heat transfer medium when the refrigeration circuit device according to embodiment 1 is operating in heat-only mode. The heat-only mode is described below with reference to Fig. 3 described, namely by illustrating an example in which all heat load units 202 perform the heating operation. In other words: Fig. Figure 3 illustrates an example in which a heating energy load is generated in both heat exchangers 3a and 3b on the load side.

[0086] In the heating-only operating mode, the controller 210 switches the flow path of the first flow switching device 41 so that the refrigerant intake inlet of the compressor 14 communicates with the outdoor heat exchanger 4. The controller 210 also switches the flow path of the second flow switching device 42 so that the refrigerant outlet of the compressor 14 communicates with the third open / close valve 53 and the fourth open / close valve 54. The controller 210 also sets the first open / close valve 51 and the second open / close valve 52 to the closed position and sets the third open / close valve 53 and the fourth open / close valve 54 to the open position.

[0087] The controller 210 also switches the flow path of the first flow switching mechanism 71 so that the heat transfer medium flow outlet of the first heat transfer medium heat exchanger 1 and the heat exchanger 3a on the load side communicate with each other. The controller 210 also switches the flow path of the second flow switching mechanism 72 so that the heat transfer medium flow inlet of the first heat transfer medium heat exchanger 1 and the heat exchanger 3a on the load side communicate with each other. The controller 210 also switches the flow path of the third flow switching mechanism 73 so that the heat transfer medium flow outlet of the second heat transfer medium heat exchanger 2 and the heat exchanger 3b on the load side communicate with each other.The controller 210 also switches the flow path of the fourth flow switching mechanism 74 so that the heat transfer medium flow inlet of the second heat transfer medium heat exchanger 2 and the heat exchanger 3b on the load side communicate with each other. The controller 210 also starts the compressor 14, the first pump 6, the second pump 7 and the outdoor fan 5.

[0088] When compressor 14 is operated, the refrigerant flows through the refrigerant circuit 100 as follows. Compressor 14 compresses low-temperature, low-pressure refrigerant and releases it as gaseous, high-temperature, high-pressure refrigerant. The gaseous, high-temperature, high-pressure refrigerant released from compressor 14 flows into the third open / close valve 53 and the fourth open / close valve 54 via the second flow changeover device 42.

[0089] The high-pressure liquid refrigerant flowing into the third open / close valve 53 enters the first heat transfer medium heat exchanger 1, which acts as a condenser. The high-temperature, high-pressure gaseous refrigerant flowing into the first heat transfer medium heat exchanger 1 transfers heat to a heat transfer medium and is transformed into high-pressure liquid refrigerant while heating the heat transfer medium. The high-pressure liquid refrigerant flowing out of the first heat transfer medium heat exchanger 1 flows into the first expansion device 21 and is expanded into a two-phase, low-temperature, low-pressure gas-liquid refrigerant.

[0090] Similarly, the liquid high-pressure refrigerant flowing into the fourth open / close valve 54 enters the second heat transfer medium heat exchanger 2, which acts as a condenser. The gaseous high-temperature, high-pressure refrigerant flowing into the second heat transfer medium heat exchanger 2 transfers heat to a heat transfer medium and is transformed into liquid high-pressure refrigerant while heating the heat transfer medium. The liquid high-pressure refrigerant flowing out of the second heat transfer medium heat exchanger 2 flows into the second expansion device 22 and is expanded into a two-phase, low-temperature, low-pressure gas-liquid refrigerant.

[0091] The two-phase, low-temperature, low-pressure gas-liquid refrigerant flowing from the first expansion unit 21 and the two-phase, low-temperature, low-pressure gas-liquid refrigerant flowing from the second expansion unit 22 merge at node b, and the combined refrigerant flows into the outdoor heat exchanger 4, which acts as an evaporator. The two-phase, low-temperature, low-pressure gas-liquid refrigerant then absorbs heat from the outdoor air and is transformed into gaseous, low-pressure refrigerant. The gaseous, low-pressure refrigerant flowing from the outdoor heat exchanger 4 passes through the first flow changeover device 41 and is drawn back into the compressor 14.

[0092] When the first pump 6 and the second pump 7 are operated, the heat transfer medium flows through the heat transfer medium circuit 110 as follows. The heat transfer medium discharged from the first pump 6 flows into the heat source unit 201 and enters the first heat transfer medium heat exchanger 1.

[0093] The heat transfer medium is then heated by the refrigerant and flows out of the first heat transfer medium heat exchanger 1. The heat transfer medium then flows into the distribution unit 203 and passes through the first flow switching mechanism 71. The heat transfer medium then flows into the heat load unit 202 and into the heat exchanger 3a on the load side. The heat transfer medium then transfers heat to the interior air, heating it. The heat transfer medium flowing out of the heat exchanger 3a on the load side flows into the distribution unit 203 and passes through the second flow switching mechanism 72. The heat transfer medium is then drawn back into the first pump 6.

[0094] The heat transfer medium discharged from the second pump 7 flows into the heat source unit 201 and enters the second heat transfer medium heat exchanger 2. The heat transfer medium is then heated by the refrigerant and flows out of the second heat transfer medium heat exchanger 2. The heat transfer medium then flows into the distribution unit 203 and passes through the third flow switching mechanism 73. The heat transfer medium then flows into the heat load unit 202 and enters the heat exchanger 3b on the load side. The heat transfer medium then transfers heat to the interior air, warming it. The heat transfer medium flowing out of the heat exchanger 3b on the load side flows into the distribution unit 203 and passes through the fourth flow switching mechanism 74. The heat transfer medium is then drawn back into the second pump 7.

[0095] While the refrigeration circuit device 200 operates in heating-only mode, the cycle described above is repeated in the refrigerant circuit 100 and in the heat transfer medium circuit 110. Heating - Main operating mode

[0096] Fig. Figure 4 is a diagram showing the refrigerant flow and the flow of a heat transfer medium when the refrigeration circuit device according to embodiment 1 is operating in the heating main operating mode. The heating main operating mode is described below with reference to Fig. 4. This is described by illustrating an example in which the heat load unit 202, which accommodates the heat exchanger 3a on the load side, performs the cooling operation, and the heat load unit 202, which accommodates the heat exchanger 3b on the load side, performs the heating operation. In other words: Fig. Figure 4 illustrates an example in which a cooling energy load is generated in heat exchanger 3a on the load side and a heating energy load is generated in heat exchanger 3b on the load side.

[0097] In the heating main operating mode, the controller 210 switches the flow path of the first flow switching device 41 so that the refrigerant intake inlet of the compressor 14 communicates with the outdoor heat exchanger 4. The controller 210 also switches the flow path of the second flow switching device 42 so that the refrigerant outlet of the compressor 14 communicates with the third open / close valve 53 and the fourth open / close valve 54. The controller 210 also sets the first open / close valve 51 and the fourth open / close valve 54 to the open state and sets the second open / close valve 52 and the third open / close valve 53 to the closed state.

[0098] The controller 210 also switches the flow path of the first flow switching mechanism 71 so that the heat transfer medium flow outlet of the first heat transfer medium heat exchanger 1 and the heat exchanger 3a on the load side communicate with each other. The controller 210 also switches the flow path of the second flow switching mechanism 72 so that the heat transfer medium flow inlet of the first heat transfer medium heat exchanger 1 and the heat exchanger 3a on the load side communicate with each other.

[0099] The controller 210 also switches the flow path of the third flow switching mechanism 73 so that the heat transfer medium flow outlet of the second heat transfer medium heat exchanger 2 and the heat exchanger 3b on the load side communicate with each other. The controller 210 also switches the flow path of the fourth flow switching mechanism 74 so that the heat transfer medium flow inlet of the second heat transfer medium heat exchanger 2 and the heat exchanger 3b on the load side communicate with each other. The controller 210 also starts the compressor 14, the first pump 6, the second pump 7, and the outdoor fan 5.

[0100] When compressor 14 is operated, the refrigerant flows through the refrigerant circuit 100 as follows. Compressor 14 compresses low-temperature, low-pressure refrigerant and releases it as a gaseous, high-temperature, high-pressure refrigerant. The gaseous, high-temperature, high-pressure refrigerant released from compressor 14 flows into the fourth open / close valve 54 via the second flow changeover device 42.

[0101] The high-pressure liquid refrigerant flowing into the fourth open / close valve 54 enters the second heat transfer medium heat exchanger 2, which acts as a condenser. The high-temperature, high-pressure gaseous refrigerant flowing into the second heat transfer medium heat exchanger 2 transfers heat to a heat transfer medium and is transformed into high-pressure liquid refrigerant while heating the heat transfer medium. The high-pressure liquid refrigerant flowing out of the second heat transfer medium heat exchanger 2 flows into the second expansion device 22 and is expanded into a two-phase, low-temperature, low-pressure gas-liquid refrigerant.

[0102] The two-phase, low-temperature, low-pressure gas-liquid refrigerant flowing from the second expansion unit 22 branches at node b. Part of the two-phase, low-temperature, low-pressure gas-liquid refrigerant flowing from the second expansion unit 22 passes through the first expansion unit 21 and flows into the first heat transfer medium heat exchanger 1, which acts as an evaporator. The remaining part of the two-phase, low-temperature, low-pressure gas-liquid refrigerant flowing from the second expansion unit 22 flows into the outdoor heat exchanger 4, which acts as an evaporator.

[0103] The two-phase, low-temperature, low-pressure gas-liquid refrigerant flowing into the first heat transfer medium heat exchanger 1 absorbs heat from the heat transfer medium and is transformed into gaseous, low-pressure refrigerant while cooling the heat transfer medium. The two-phase, low-temperature, low-pressure gas-liquid refrigerant flowing into the outdoor space heat exchanger 4 absorbs heat from the outdoor air and is transformed into gaseous, low-pressure refrigerant. The gaseous, low-pressure refrigerant flowing from the heat transfer medium heat exchanger 1 passes through the first open / close valve 51 and flows towards node c. The gaseous, low-pressure refrigerant flowing from the outdoor space heat exchanger 4 passes through the first flow changeover device 41 and also flows towards node c.These low-pressure gas refrigerants then combine at node c, and the combined refrigerant is drawn back into compressor 14.

[0104] When the first pump 6 and the second pump 7 are operating, the heat transfer medium flows through the heat transfer medium circuit 110 as follows. The heat transfer medium discharged from the first pump 6 flows into the heat source unit 201 and enters the first heat transfer medium heat exchanger 1. The heat transfer medium is then cooled by the refrigerant and flows out of the first heat transfer medium heat exchanger 1. The heat transfer medium then flows into the distribution unit 203 and passes through the first flow switching mechanism 71. The heat transfer medium then flows into the heat load unit 202 and enters the heat exchanger 3a on the load side. The heat transfer medium then absorbs heat from the interior air and cools it. The heat transfer medium flowing from the heat exchanger 3a on the load side flows into the transfer unit 203 and passes through the second flow switching mechanism 72. The heat transfer medium is then drawn back into the first pump 6.

[0105] The heat transfer medium discharged from the second pump 7 flows into the heat source unit 201 and enters the second heat transfer medium heat exchanger 2. The heat transfer medium is then heated by the refrigerant and flows out of the second heat transfer medium heat exchanger 2. The heat transfer medium then flows into the distribution unit 203 and passes through the third flow switching mechanism 73. The heat transfer medium then flows into the heat load unit 202 and enters the heat exchanger 3b on the load side. The heat transfer medium then transfers heat to the interior air, warming it. The heat transfer medium flowing out of the heat exchanger 3b on the load side flows into the distribution unit 203 and passes through the fourth flow switching mechanism 74. The heat transfer medium is then drawn back into the second pump 7.

[0106] While the refrigeration circuit device 200 is operating in the heating main operating mode, the cycle described above is repeated in the refrigerant circuit 100 and in the heat transfer medium circuit 110.

[0107] As described above, the refrigeration circuit device 200 according to embodiment 1 includes a heat source unit 201. The heat source unit 201 has a heat transfer medium heat exchanger in which refrigerant circulating in a refrigerant circuit 100 and a heat transfer medium, which is a medium other than the refrigerant, exchange heat. The heat source unit 201 discharges the heat transfer medium, which has exchanged heat with the refrigerant in the heat transfer medium heat exchanger, to the outside of the heat source unit 201. The refrigeration circuit device 200 also has a heat transfer medium circuit 110 in which the heat transfer medium supplied by the heat source unit 201 circulates.The heat transfer medium circuit 110 has several heat exchangers on the load side and a switching mechanism 70 configured to switch the distribution state of the heat transfer medium so that it flows into and out of each of the heat exchangers on the load side. The refrigeration circuit device 200 also has a distribution unit 203 that incorporates the switching mechanism 70.

[0108] In the refrigeration circuit device 200, configured as described above, the line to be installed at the installation site, which is equivalent to the main line of a known refrigeration circuit device, is a line connecting the heat source unit and the distribution unit. Therefore, in the refrigeration circuit device 200, configured as described above, the line to be installed at the installation site can be shorter than the main line of the known refrigeration circuit device. Consequently, the installation time of the refrigeration circuit device 200 at the installation site can be reduced compared to the previous configuration. Design 2

[0109] By adding a bypass circuit, as discussed in embodiment 2, to the refrigeration circuit device 200 in embodiment 1, the reliability of the refrigeration circuit device 200 is improved. Aspects similar to those in embodiment 1 are not described in embodiment 2, and those elements in embodiment 2 that perform functions similar to those in embodiment 1 are provided with the same reference numerals as in embodiment 1.

[0110] Fig. 5 and Fig. Figure 6 shows an example of a circuit configuration of the refrigeration circuit device according to embodiment 2. Fig. Figure 5 illustrates the operating state of the refrigeration circuit device 200, which performs frost protection operation in cooling-only operating mode. Fig. Figure 5 illustrates the operating state of the refrigeration circuit device 200, which performs an antifreeze operation in the main cooling operating mode.

[0111] The heat transfer medium circuit 110 of the refrigeration circuit device 200 according to embodiment 2 has a bypass circuit 8. The bypass circuit 8 connects a portion of the first circuit 111 between the first heat transfer medium heat exchanger 1 and the first pump 6 with a portion of the second circuit 112 between the second heat transfer medium heat exchanger 2 and the second pump 7. In other words, one end of the bypass circuit 8 is connected to the portion of the first circuit 111 between the first heat transfer medium heat exchanger 1 and the first pump 6, while the other end of the bypass circuit 8 is connected to the portion of the second circuit 112 between the second heat transfer medium heat exchanger 2 and the second pump 7. The bypass circuit 8 is incorporated in the distribution unit 203.The position where the bypass circuit 8 is connected to the part of the first circuit 111 between the first heat transfer medium heat exchanger 1 and the first pump 6 is referred to as node e.

[0112] While the heat transfer medium heat exchanger is operating as an evaporator, the following applies: If the temperature of the refrigerant flowing through the heat transfer medium heat exchanger becomes excessively low, the heat transfer medium can reach the freezing point of water and freeze within the heat transfer medium heat exchanger. To counteract this, the following applies: When a predefined operating condition is met, the controller 210 of the refrigeration circuit device 200 performs frost protection operation to prevent the heat transfer medium from freezing within the heat transfer medium heat exchanger. For example, the operating condition is that the temperature of the refrigerant flowing into the heat transfer medium heat exchanger, operating as an evaporator, becomes lower than or equal to a first predefined temperature.

[0113] The operating condition is, for example, the condition that the temperature of the heat transfer medium flowing from the heat transfer medium heat exchanger, which acts as an evaporator, becomes lower than or equal to a second predetermined temperature. The pressure of the refrigerant flowing into the heat transfer medium heat exchanger, which acts as an evaporator, and the pressure of the refrigerant flowing out of the heat transfer medium heat exchanger, which acts as an evaporator, are correlated with the evaporation temperature of the refrigerant flowing through this heat transfer medium heat exchanger. Consequently, the operating condition can be, for example, the condition that the pressure of the refrigerant flowing into the heat transfer medium heat exchanger, which acts as an evaporator, becomes lower than or equal to a predetermined pressure.Consequently, the operating condition can be, for example, the condition that the pressure of the refrigerant flowing from the heat transfer medium heat exchanger, which acts as an evaporator, becomes lower than or equal to a predetermined pressure.

[0114] In one example, the refrigeration circuit device 200 has a sensor 81, which is a temperature sensor or a pressure sensor, located between the first expansion device 21 and the first heat transfer medium heat exchanger 1 in the refrigerant circuit 100. This enables the controller 210 to detect, based on the detection value of the sensor 81, whether the first heat transfer medium heat exchanger 1, which operates as an evaporator, meets the operating conditions for performing the frost protection operation.

[0115] In one example, the refrigeration circuit device 200 has a sensor 82, which is a pressure sensor, located between the first heat transfer medium heat exchanger 1 and the first opening / closing valve 51 in the refrigerant circuit 100. This enables the controller 210 to detect, based on the detection value of the sensor 82, whether the first heat transfer medium heat exchanger 1, which operates as an evaporator, meets the operating conditions for performing the frost protection operation.

[0116] In one example, the refrigeration circuit device 200 has a sensor 83, which is either a temperature or pressure sensor, located between the second expansion device 22 and the second heat transfer medium heat exchanger 2 in the refrigerant circuit 100. This allows the controller 210 to detect, based on the detection value of sensor 83, whether the second heat transfer medium heat exchanger 2, which operates as an evaporator, meets the operating conditions for performing frost protection operation. In another example, the refrigeration circuit device 200 has a sensor 84, which is a pressure sensor, located between the second heat transfer medium heat exchanger 2 and the second open / close valve 52 in the refrigerant circuit 100.This enables the control unit 210 to detect, based on the detection value of the sensor 84, whether the second heat transfer medium heat exchanger 2, which operates as an evaporator, meets the operating conditions for carrying out the frost protection operation.

[0117] In one example, the refrigeration circuit device 200 has a sensor 85, which is a pressure sensor, located between node c and the intake inlet of the compressor 14 in the refrigerant circuit 100. This allows the controller 210 to detect, based on the detection value of sensor 85, whether one of the heat transfer medium heat exchangers, which operate as evaporators, meets the operating condition for performing the frost protection operation. In another example, the refrigeration circuit device 200 has a sensor 86, which is a temperature sensor, located between the first heat transfer medium heat exchanger 1 and the first flow switching mechanism 71 in the heat transfer medium circuit 110.

[0118] This enables the controller 210 to detect, based on the detection value of sensor 86, whether the first heat transfer medium heat exchanger 1, which operates as an evaporator, meets the operating conditions for performing frost protection. In one example, the refrigeration circuit device 200 has a sensor 87, which is a temperature sensor, located between the second heat transfer medium heat exchanger 2 and the third flow switching mechanism 73 in the heat transfer medium circuit 110. This enables the controller 210 to detect, based on the detection value of sensor 87, whether the second heat transfer medium heat exchanger 2, which operates as an evaporator, meets the operating conditions for performing frost protection.

[0119] It is not essential that the refrigeration circuit device 200 has all of the sensors 81 to 87 described above. The necessary sensors can be selected from among 81 to 87 so that the controller 210 can detect whether the corresponding heat transfer medium heat exchanger meets the operating conditions.

[0120] The operation of the refrigeration circuit device 200 is described below with reference to a refrigerant flow and that of a heat transfer medium. The following description explains the operation of the refrigeration circuit device 200 by illustrating the frost protection operation in cooling-only mode and in main cooling mode. The frost protection operation in cooling-only mode and in main cooling mode is discussed by illustrating an example in which the first heat transfer medium heat exchanger 1 fulfills the operating conditions for performing the frost protection operation. Frost protection operation in cooling-only operating mode

[0121] In the state where the refrigeration circuit device 200 is operating in cooling-only mode, as in Fig. As shown in Figure 1, the following applies: If it is detected that the first heat transfer medium heat exchanger 1 meets the operating condition for performing the frost protection operation, the refrigeration circuit device 200 performs the frost protection operation as shown in Figure 1. Fig. 5 illustrates.

[0122] The controller 210 positions the second open / close valve 52 in the closed state. The controller 210 also switches the flow path of the third flow switching mechanism 73 so that the heat exchanger 3b on the load side communicates with the line connecting the first flow switching mechanism 71 and the heat exchanger 3a on the load side. The controller 210 can also increase the opening degree of the first expansion device 21, thus increasing the temperature of the refrigerant flowing into the first heat transfer medium heat exchanger 1.

[0123] The section where the line running from the third flow switching mechanism 73 connects to the line connecting the first flow switching mechanism 71 and the heat exchanger 3a on the load side is referred to as node d. The section where the line running from the fourth flow switching mechanism 74 connects to the line connecting the second flow switching mechanism 72 and the heat exchanger 3b on the load side is referred to as node f.

[0124] In frost protection mode, the refrigerant flow in refrigerant circuit 100 is increased from the state in Fig. 1 is modified as follows. As a result of the second opening / closing valve 52 being set to the closed state, the refrigerant flow into the second heat transfer medium heat exchanger 2 is interrupted. That is, the refrigerant does not flow through the second heat transfer medium heat exchanger 2. Apart from this, the refrigerant flow is similar to that in Fig. 1.

[0125] In frost protection mode, the flow of the heat transfer medium in heat transfer medium circuit 110 is changed from the state in Fig. 1 is modified as follows. As a result of the flow path of the third flow switching mechanism 73 being switched as described above, the flow of the heat transfer medium from the second heat transfer medium heat exchanger 2 to the heat exchanger 3b on the load side is interrupted. This prevents the heat transfer medium from flowing through the second heat transfer medium heat exchanger 2. Instead, the heat transfer medium flows from the first heat transfer medium heat exchanger 1 to the heat exchanger 3b on the load side.

[0126] This is described in more detail below. The heat transfer medium discharged from the second pump 7 passes through the bypass circuit 8 and merges with the heat transfer medium discharged from the first pump 6 at node e. The combined heat transfer medium flows into the first heat transfer medium heat exchanger 1. The heat transfer medium is then cooled by the refrigerant and flows out of the first heat transfer medium heat exchanger 1. The heat transfer medium then flows into the distribution unit 203 and passes through the first flow switching mechanism 71. The heat transfer medium then branches at node d. A portion of the heat transfer medium passing through the first flow switching mechanism 71 flows into the heat load unit 202 and enters the heat exchanger 3a on the load side. The remaining heat transfer medium passing through the first flow switching mechanism 71 passes through the second flow switching mechanism 72.

[0127] The heat transfer medium entering heat exchanger 3a on the load side absorbs heat from the indoor air and cools it. The heat transfer medium flowing out of heat exchanger 3a on the load side flows into the distribution unit 203 and passes through the second flow switching mechanism 72. The heat transfer medium is then drawn into the first pump 6. Meanwhile, the heat transfer medium passing through the second flow switching mechanism 72 flows into the heat load unit 202 and enters heat exchanger 3b on the load side. The heat transfer medium then absorbs heat from the indoor air and cools it. The heat transfer medium flowing out of heat exchanger 3b on the load side flows into the distribution unit 203 and passes through the fourth flow switching mechanism 74. The heat transfer medium is then drawn into the second pump 7. Frost protection operation in cooling main operating mode

[0128] In the state in which the refrigeration circuit device 200 is operating in main cooling mode, as in Fig. As shown in Figure 2, the following applies: If it is detected that the first heat transfer medium heat exchanger 1 meets the operating condition for performing the frost protection operation, the refrigeration circuit device 200 performs the frost protection operation as shown in Figure 2. Fig. 6 illustrates.

[0129] The controller 210 sets the fourth open / close valve 54 to the closed position. The controller 210 also switches the flow path of the third flow switching mechanism 73 so that the heat exchanger 3b on the load side communicates with the line connecting the first flow switching mechanism 71 and the heat exchanger 3a on the load side. The controller 210 also switches the flow path of the fourth flow switching mechanism 74 so that the second pump 7 communicates with the line connecting the second flow switching mechanism 72 and the heat exchanger 3a on the load side. The controller 210 can also increase the opening degree of the first expansion device 21, thus increasing the temperature of the refrigerant flowing into the first heat transfer medium heat exchanger 1.

[0130] In frost protection mode during main cooling operation, the refrigerant flow in refrigerant circuit 100 is increased from the state in Fig. 2 is modified as follows. As a result of the fourth opening / closing valve 54 being set to the closed state, the refrigerant flow into the second heat transfer medium heat exchanger 2 is interrupted. That is, the refrigerant does not flow through the second heat transfer medium heat exchanger 2. Apart from this, the refrigerant flow is similar to that in Fig. 2.

[0131] In frost protection mode during main cooling operation, the flow of the heat transfer medium in heat transfer medium circuit 110 is changed from the state in Fig. 2 as follows. As a result of the flow path of the third flow switching mechanism 73 being switched as described above, the flow of the heat transfer medium from the second heat transfer medium heat exchanger 2 to the heat exchanger 3b on the load side is interrupted.

[0132] This prevents the heat transfer medium from flowing through the second heat transfer medium heat exchanger 2. As a result of the flow path of the fourth flow switching mechanism 74 being switched, as described above, the heat transfer medium does not flow through the heat exchanger 3b on the load side, and instead the heat transfer medium flowing from the heat exchanger 3a on the load side is drawn into the second pump 7.

[0133] This is described in more detail below. The heat transfer medium discharged from the second pump 7 passes through the bypass circuit 8 and merges with the heat transfer medium discharged from the first pump 6 at node e. The combined heat transfer medium flows into the first heat transfer medium heat exchanger 1. The heat transfer medium is then cooled by the refrigerant and flows out of the first heat transfer medium heat exchanger 1. The heat transfer medium then flows into the distribution unit 203 and passes through the first flow switching mechanism 71. The heat transfer medium then flows into the heat load unit 202 and enters the heat exchanger 3a on the load side. The heat transfer medium that has entered heat exchanger 3a on the load side absorbs heat from the interior air and cools it. The heat transfer medium flowing out of heat exchanger 3a on the load side enters the distribution unit 203.

[0134] The heat transfer medium 3a, which entered the distribution unit 203, branches at node f. Part of the heat transfer medium that entered the distribution unit 203 passes through the second flow switching mechanism 72 and is drawn into the first pump 6. The remaining heat transfer medium that entered the distribution unit 203 passes through the fourth flow switching mechanism 74 and is drawn into the second pump 7.

[0135] As described above, the refrigeration circuit device 200 according to embodiment 2 has the bypass circuit 8 and consequently achieves the following advantages, in addition to those according to embodiment 1.

[0136] When the frost protection operation is carried out while the heat load unit 202, which performs the cooling operation, is allowed to continue, the refrigeration circuit device 200 according to embodiment 2 causes a heat transfer medium discharged by the first pump 6 and that from the second pump 7 to flow through the heat transfer medium heat exchanger, which has met the operating condition for carrying out the frost protection operation.

[0137] As a result of the heat transfer medium discharged from the first pump 6 and that from the second pump 7 flowing through this heat transfer medium heat exchanger, the volume flow rate of the heat transfer medium in this heat transfer medium heat exchanger is increased, thus preventing the heat transfer medium from freezing in the heat transfer medium heat exchanger. In other words, by operating the frost protection mode, the refrigeration circuit device 200 according to embodiment 2 can prevent the heat transfer medium from freezing in the heat transfer medium heat exchanger, while allowing the heat load unit 202, which performs the cooling operation, to continue. embodiment 3

[0138] By adding an opening / closing valve, discussed in embodiment 3, to the bypass circuit 8 of the refrigeration circuit device 200 in embodiment 2, a deterioration in the performance of the refrigeration circuit device 200 is suppressed. Aspects similar to those in embodiment 1 or 2 are not described in embodiment 3, and those elements in embodiment 3 that perform functions similar to those in embodiment 1 or 2 are provided with the same reference numerals as in embodiment 1 or 2.

[0139] Fig. 7 and Fig. Figure 8 shows a diagram illustrating an example of the circuit configuration of a refrigeration circuit device according to embodiment 3. Fig. Figure 7 illustrates the operating state of the refrigeration circuit device 200, which performs the frost protection operation in cooling-only operating mode. Fig. Figure 8 illustrates the operating state of the refrigeration circuit device 200, which performs the frost protection operation in the main cooling operating mode.

[0140] The heat transfer medium circuit 110 of the refrigeration circuit device 200 according to embodiment 3 has an opening / closing valve 9, which is arranged in the bypass circuit 8, so that the bypass circuit 8 is opened and closed. The open / closed state of the opening / closing valve 9 is controlled by the controller 210.

[0141] The refrigeration circuit device 200 according to embodiment 3 is operated as follows. While the refrigeration circuit device 200 is not performing frost protection operation, it controls the opening / closing valve 9 in the closed position. While the refrigeration circuit device 200 is performing frost protection operation, it controls the opening / closing valve 9 in the open position.

[0142] It is now assumed that the refrigeration circuit device 200, which has the bypass circuit 8, operates in either cooling or heating mode. In other words, it is assumed that the refrigeration circuit device 200, which has the bypass circuit 8, cools a heat transfer medium in one circuit between the first heat transfer medium heat exchanger 1 and the second heat transfer medium heat exchanger 2, and heats a heat transfer medium in the other circuit between the first heat transfer medium heat exchanger 1 and the second heat transfer medium heat exchanger 2. That is, in the heat transfer medium circuit 110 of the refrigeration circuit device 200, the temperature of the heat transfer medium circulating in the first circuit 111 and that in the second circuit 112 are different from each other.

[0143] It is also assumed that in the heat transfer medium circuit 110, the pressure of the heat transfer medium discharged from the first pump 6, located in the first circuit 111, and that of the second pump 7, located in the second circuit 112, differ from each other. Under such operating conditions, the following phenomenon can occur if the open / close valve 9 is not located in the bypass circuit 8: The heat transfer medium can pass through the bypass circuit 8 and flow from one end of the first circuit 111 and the second circuit 112 to the other end of the first circuit 111 and the second circuit 112. This can lead to a deterioration in the performance of the refrigeration circuit device 200.

[0144] The refrigeration circuit device 200 according to embodiment 3 can address the problem described above by ensuring that the opening / closing valve 9 is in the closed position when it is not performing the frost protection operation. That is, the refrigeration circuit device 200 according to embodiment 3 can suppress the performance deterioration that would be caused by providing the bypass circuit 8. Design 4

[0145] By adding an air purge valve, which is discussed in embodiment 4, to the bypass circuit 8 of the refrigeration circuit device 200 in embodiment 2 or 3, the on-site installation of the refrigeration circuit device 200 is facilitated. Aspects similar to those of embodiments 1 to 3 are not described in embodiment 4, and those elements in embodiment 4 that perform functions similar to those in embodiments 1 to 3 are provided with the same reference numerals as in embodiments 1 to 3.

[0146] Fig. 9 and Fig. Figure 10 are diagrams illustrating an example of the circuit configuration of a refrigeration circuit device according to embodiment 4. Fig. Figure 9 illustrates the operating state of the refrigeration circuit device 200, which performs the frost protection operation in cooling-only operating mode. Fig. Figure 10 illustrates the operating state of the refrigeration circuit device 200, which performs the frost protection operation in the main cooling operating mode.

[0147] The heat transfer medium circuit 110 of the refrigeration circuit device 200 according to embodiment 4 has an air purge valve 10, which is arranged in the bypass circuit 8. The air purge valve 10 is opened when air purging or air expulsion is carried out from the heat transfer medium circuit 110. The air purge valve 10 is closed at all other times. The air purge valve 10 is opened and closed, for example, by an operator.

[0148] When the on-site installation of the refrigeration circuit device 200 is carried out, the heat source unit 201, the distribution unit 203, and the heat load units 202 are installed at predetermined locations. Then, the heat source unit 201 and the distribution unit 203 are connected to each other by a pipe, and the distribution unit 203 and the heat load units 202 are also connected to each other by a pipe. A heat transfer medium is then introduced into the heat transfer medium circuit 110. At this time, it is necessary to expel or purge the air from the heat transfer medium circuit 110.

[0149] If the refrigeration circuit device 200 does not have the bypass circuit 8 and the air purge valve 10, the air purge from the heat transfer medium circuit 110 is carried out, for example, as follows. The flow path of each of the first flow switching mechanism 71, the second flow switching mechanism 72, the third flow switching mechanism 73, and the fourth flow switching mechanism 74 is first switched so that the heat exchangers 3a and 3b on the load side form the first circuit 111. In other words, the flow path of each of the first flow switching mechanism 71, the second flow switching mechanism 72, the third flow switching mechanism 73, and the fourth flow switching mechanism 74 is switched so that the heat exchangers 3a and 3b on the load side communicate with the first heat transfer medium heat exchanger 1.

[0150] The air purge from the first circuit 111 is then carried out. The flow path of each of the first flow switching mechanism 71, the second flow switching mechanism 72, the third flow switching mechanism 73, and the fourth flow switching mechanism 74 is then switched so that the heat exchangers 3a and 3b on the load side form the second circuit 112. In other words, the flow path of each of the first flow switching mechanism 71, the second flow switching mechanism 72, the third flow switching mechanism 73, and the fourth flow switching mechanism 74 is switched so that the heat exchangers 3a and 3b on the load side communicate with the second heat transfer medium heat exchanger 2. Then the air purge from the second circuit 112 is carried out.

[0151] In contrast, in the heat transfer medium circuit 110 of the refrigeration circuit device 200 according to embodiment 4, the first circuit 111 and the second circuit 112 communicate with each other via the bypass circuit 8. With this configuration of the heat transfer medium circuit 110 of the refrigeration circuit device 200 according to embodiment 4, the flow path of each of the first flow switching mechanism 71, the second flow switching mechanism 72, the third flow switching mechanism 73 and the fourth flow switching mechanism 74 is switched such that the heat exchangers 3a and 3b on the load side form the first circuit 111 or the second circuit 112.In other words, the flow path of each of the first flow switching mechanism 71, the second flow switching mechanism 72, the third flow switching mechanism 73, and the fourth flow switching mechanism 74 is switched such that the heat exchangers 3a and 3b on the load side communicate with the first heat transfer medium heat exchanger 1 or the second heat transfer medium heat exchanger 2.

[0152] Then the air purge valve 10 is opened. As a result, the refrigeration circuit device 200 according to embodiment 4 can purge air from the heat transfer medium circuit 110 at a time without having to re-switch the flow path of each of the first flow switching mechanism 71, the second flow switching mechanism 72, the third flow switching mechanism 73, and the fourth flow switching mechanism 74. This simplifies the installation of the refrigeration circuit device 200 according to embodiment 4 at the installation site. Design 5

[0153] The refrigeration circuit devices 200 according to embodiments 1 to 4 have a single heat source unit. That is, the refrigeration circuit devices 200 according to embodiments 1 to 4 have the heat source unit 201 as the heat source unit. However, the refrigeration circuit device can also have several heat source units. Aspects similar to those according to embodiments 1 to 4 are not described in embodiment 5, and those elements in embodiment 5 that perform functions similar to those in embodiments 1 to 4 are provided with the same reference numerals as in embodiments 1 to 4.

[0154] Fig. Figure 11 is a diagram showing an example of the circuit configuration of a refrigeration circuit device according to embodiment 5.

[0155] As a heat source unit, the refrigeration circuit device 200 according to embodiment 5 has a first heat source unit 201a, which accommodates the first heat transfer medium heat exchanger 1, and a second heat source unit 201b, which accommodates the second heat transfer medium heat exchanger 2.

[0156] The refrigerant circuit 100, which is housed in the first heat source unit 201a, is configured as follows. The compressor 14, the outdoor heat exchanger 4, an expansion device 20, and the first heat transfer medium heat exchanger 1 are connected to each other by means of a refrigerant line in a ring-like configuration, thus forming the refrigerant circuit 100 housed in the first heat source unit 201a. The expansion device 20 is configured similarly to the first expansion device 21 and the second expansion device 22. That is, the expansion device 20 functions as a reducing valve or expansion valve and is used to expand the refrigerant, thereby reducing its pressure.

[0157] The refrigerant circuit 100, which is incorporated in the first heat source unit 201a, has a flow switching device 40, which is, for example, a four-way valve. The flow switching device 40 changes the flow path so that the heat exchanger to be connected to the refrigerant outlet of the compressor 14 is switched, and also so that the heat exchanger to be connected to the refrigerant intake inlet of the compressor 14 is switched. More precisely: The flow switching device 40 connects the refrigerant outlet of the compressor 14 to one of the outdoor heat exchangers 4 and the first heat transfer medium heat exchanger 1, while the refrigerant intake inlet of the compressor 14 is connected to the other of the outdoor heat exchanger 4 and the first heat transfer medium heat exchanger 1.By arranging the flow switching device 40, the first heat transfer medium heat exchanger 1 can operate as a condenser and also as an evaporator.

[0158] The refrigerant circuit 100, which is included in the second heat source unit 201b, is configured similarly to the one included in the first heat source unit 201a, except that it has the second heat transfer medium heat exchanger 2 instead of the first heat transfer medium heat exchanger 1.

[0159] The forwarding unit 203, the heat load units 202 and the heat transfer medium circuit 110 are configured as in one of embodiments 1 to 4.

[0160] Even with the heat source unit configured as in embodiment 5, the refrigeration circuit device 200 can achieve the same advantages as those in embodiments 1 to 4. Reference symbol list 1 first heat transfer medium heat exchanger, 2 second heat transfer medium heat exchanger, 3a Heat exchanger on the load side, 3b Heat exchanger on the load side, 4 outdoor heat exchangers, 5 outdoor fans, 6 first pump, 7 second pump, 8 Bypass circuit, 9 opening / closing valves, 10 air purge valve, 14 Compressor, 20 expansion facility, 21 first expansion facility, 22 second expansion facility, 40 Flow switching device, 41 first flow switching device, 42 second flow switching device, 51 first opening / closing valve, 52 second opening / closing valve, 53 third opening / closing valve, 54 fourth opening / closing valve, 70 switching mechanism, 71 first flow switching mechanism, 72 second flow switching mechanism, 73 third flow switching mechanism, 74 fourth flow switching mechanism, 81 Sensor, 82 Sensor, 83 Sensor, 84 Sensor, 85 Sensor, 86 Sensor, 87 Sensor, 100 refrigerant circuit, 110 Heat transfer medium circuit, 111 first circle, 112 second circle, 200 refrigeration circuit device, 201 Heat source unit, 201a first heat source unit, 201b second heat source unit, 202 heat load unit, 203 Forwarding unit, 210 control, a node, b nodes, c nodes, d nodes, e nodes, f nodes QUOTES INCLUDED IN THE DESCRIPTION

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

[0000] JP H4 - 214 134 A

[0006]

Claims

[1] Refrigeration circuit apparatus comprising a heat source unit, wherein the heat source unit comprises a heat transfer medium heat exchanger in which a heat transfer medium, which is a medium other than refrigerant circulating in a refrigerant circuit, and the refrigerant exchange heat with each other, wherein the heat source unit discharges the heat transfer medium, which has exchanged heat with the refrigerant in the heat transfer medium heat exchanger, to the outside of the heat source unit, wherein the refrigeration circuit apparatus comprises: a heat transfer medium circuit in which the heat transfer medium supplied by the heat source unit circulates, wherein the heat transfer medium circuit comprises the following: a plurality of heat exchangers on the load side, a switching mechanism configured to switch a distribution state of the heat transfer medium that is to flow into and out of each of the heat exchangers on the load side, and a forwarding unit that incorporates the switching mechanism. [2] Refrigeration circuit device according to claim 1, wherein: the heat transfer medium heat exchanger has a first heat transfer medium heat exchanger and a second heat transfer medium heat exchanger; The heat transfer medium circuit has the following features: a first circuit that allows the heat transfer medium to pass through it and flow into the first heat transfer medium heat exchanger, and a second circuit that allows the heat transfer medium to pass through it and flow into the second heat transfer medium heat exchanger; and the switching mechanism is configured to switch the distribution state of the heat transfer medium flowing out of the first heat transfer medium heat exchanger so that it flows into each of the heat exchangers on the load side, and the distribution state of the heat transfer medium flowing out of the second heat transfer medium heat exchanger so that it flows into each of the heat exchangers on the load side. [3] Refrigeration circuit device according to claim 2, wherein the heat transfer medium circuit comprises: a first pump, which is located at a position in the first circuit where the heat transfer medium flows, which is to go into the first heat transfer medium heat exchanger, and which discharges the heat transfer medium so that it goes into the first heat transfer medium heat exchanger, a second pump, which is located at a position in the second circuit where the heat transfer medium flows, which is to go into the second heat transfer medium heat exchanger, and which discharges the heat transfer medium so that it goes into the second heat transfer medium heat exchanger, a bypass circuit that connects part of the first circuit between the first heat transfer medium heat exchanger and the first pump and part of the second circuit between the second heat transfer medium heat exchanger and the second pump. [4] Refrigeration circuit device according to claim 3, wherein the heat transfer medium circuit has an opening / closing valve arranged in the bypass circuit for opening and closing the bypass circuit. [5] Refrigeration circuit device according to claim 3 or 4, wherein the heat transfer medium circuit has an air purge valve arranged in the bypass circuit. [6] Refrigeration circuit device according to one of claims 2 to 5, wherein the heat source unit comprises a first heat source unit and a second heat source unit, wherein the first heat source unit accommodates the first heat transfer medium heat exchanger therein, and wherein the second heat source unit accommodates the second heat transfer medium heat exchanger therein.

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