Refrigeration device

Abstract

A first heat exchanger (13), a compressor (12), and an expansion valve (15) included in a refrigeration device (R1) are provided outdoors, and are connected to a first pipe (11) for circulating a first working medium (an outdoor-side circuit (10)). A second heat exchanger (23) included in a refrigeration device (R1) is provided indoors and is connected to a second pipe (21) for circulating a second working medium to the second heat exchanger (indoor-side circuit 20). The refrigeration device (R1) is further provided with a secondary heat exchanger (30) that is provided between the first pipe (11) and the second pipe (21), is provided outdoors, and exchanges heat between the first working medium and the second working medium. The first working medium contains at least fluoroolefin, and the second working medium does not contain fluoroolefin. Thus, even if the fluoroolefin is subjected to a disproportionation reaction, the influence of the disproportionation reaction on the fluoroolefin can be well prevented from entering the room.

Description

Technical Field

[0001] The present invention relates to a refrigeration apparatus using a refrigeration cycle working medium containing fluoroolefin, and more particularly to a refrigeration apparatus capable of satisfactorily avoiding the influence of a disproportionation reaction of fluoroolefin. Background Art

[0002] The working medium for the refrigeration cycle is usually composed of a refrigerant and refrigeration oil (lubricating oil stored in a sealed compressor). HCFC (hydrochlorofluorocarbon) was previously used as a refrigerant, but HCFC has a great impact on ozone layer destruction. Therefore, in recent years, HFC (hydrofluorocarbon) with an ozone depletion potential (ODP) of 0 is used. Representative HFCs include difluoromethane (HFC32, R32).

[0003] However, HFC, which is stable as a working medium for refrigeration cycles, has a large global warming potential (GWP) due to its long atmospheric life. Therefore, the use of fluoroolefins, especially hydrofluoroolefins (HFO), with a lower GWP (Global Warming Potential) has recently been proposed. Among HFOs, 1,1,2-trifluoroethylene (HFO1123) is known as an HFO with a low GWP, high cooling capacity, and performance close to that of the currently widely used R32.

[0004] As a refrigeration device using fluoroolefin such as HFO1123, for example, a device disclosed in Patent Document 1 has been proposed.

[0005] The refrigeration device disclosed in Patent Document 1 has a binary cycle (double cycle) of a heat source heat medium circuit and a load heat medium circuit, and at least one of the heat source heat medium and the load heat medium used in these circuits is a refrigerant containing HFO1123. The heat source heat medium circuit includes a cascade heat exchanger for performing heat exchange between the heat source heat medium and the load heat medium.

[0006] In this refrigeration device, the heat source heat medium circuit is arranged in the outdoor space, and the load heat exchanger in the load heat medium circuit is arranged in the indoor space. Therefore, the cascade heat exchanger included in the heat source heat medium circuit is arranged in the outdoor space.

[0007] Prior art literature

[0008] Patent Literature

[0009] Patent Document 1: International Publication No. 2015 / 140872 Summary of the invention

[0010] Technical problem to be solved by the invention

[0011] The low GWP of fluoroolefins means that their atmospheric lifetime is short. In other words, fluoroolefins are easily chemically decomposed and have low stability. Therefore, it is known that a self-polymerization reaction called a disproportionation reaction (hereinafter referred to as a disproportionation reaction) is easily generated in fluoroolefins such as HFO1123.

[0012] It is generally believed that the disproportionation reaction is easily induced by high pressure or heat during the use of the working medium for the refrigeration cycle. It is also known that since a large amount of heat is released during the disproportionation reaction, the disproportionation reaction occurs in a chain reaction. As a result, a large amount of soot is generated, which may reduce the reliability of the refrigeration cycle system.

[0013] In the refrigeration device disclosed in Patent Document 1, as described above, in the binary cycle of the heat source heat medium circuit and the load heat medium circuit, HFO1123 can be used as either working medium (heat source heat medium and load heat medium). However, in Patent Document 1, when fluoroolefins such as HFO1123 undergo a disproportionation reaction, the influence of the disproportionation reaction on the heat source heat medium circuit and the load heat medium circuit is not considered.

[0014] The present invention is completed to solve the above-mentioned technical problems. Its purpose is to use fluoroolefins as working media in a refrigeration device that forms a binary cycle of indoor and outdoor circuits, so that even if fluoroolefins undergo disproportionation reaction, their influence can be well avoided from affecting the indoor environment.

[0015] Technical means for solving technical problems

[0016] In order to solve the above technical problems, the refrigeration device of the present invention includes a first heat exchanger, a second heat exchanger, a compressor and an expansion mechanism, wherein the first heat exchanger, the compressor and the expansion mechanism are arranged outdoors and are connected to a first pipe to form an outdoor side circuit, wherein the first pipe is used to circulate a first working medium to the first heat exchanger, the compressor and the expansion mechanism, and the second heat exchanger is arranged indoors and is connected to a second pipe used to circulate a second working medium to the second heat exchanger to form an indoor side circuit, and the refrigeration device also includes a secondary heat exchanger, which is arranged between the first pipe and the second pipe and is used to exchange heat between the first working medium and the second working medium, and the secondary heat exchanger is arranged outdoors, the first working medium contains at least fluoroolefins, and the second working medium does not contain fluoroolefins.

[0017] According to the above structure, fluoroolefins that may undergo a disproportionation reaction are not used in the second working medium circulating in the indoor circuit, and fluoroolefins are used in the first working medium circulating in the outdoor circuit. In addition, a secondary heat exchanger capable of performing heat exchange between the indoor circuit and the outdoor circuit is arranged outdoors. Thus, even if a disproportionation reaction occurs in the fluoroolefin in the outdoor circuit and its influence spreads to the secondary heat exchanger, the influence can be limited to the outdoor equipment. Therefore, the influence of the disproportionation reaction can be effectively prevented from spreading to the indoor room.

[0018] The following detailed description of preferred embodiments will make clear the above-mentioned objects, other objects, features and advantages of the present invention.

[0019] Effects of the Invention

[0020] In the present invention, by adopting the above structure, in a refrigeration apparatus using fluoroolefin as a working medium and forming a binary cycle of an indoor circuit and an outdoor circuit, even if the fluoroolefin undergoes a disproportionation reaction, its influence can be well avoided from affecting the indoor environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a schematic circuit diagram showing a typical configuration example of a refrigeration device according to an embodiment of the present invention.

[0022] Figure 2 This is a schematic circuit diagram showing a typical configuration example of a refrigeration apparatus according to Embodiment 2 of the present invention.

[0023] Figure 3 This is a schematic circuit diagram showing a typical configuration example of a refrigeration apparatus according to Embodiment 3 of the present invention. DETAILED DESCRIPTION

[0024] The refrigeration device of the present invention includes a first heat exchanger, a second heat exchanger, a compressor and an expansion mechanism, wherein the first heat exchanger, the compressor and the expansion mechanism are arranged outdoors and are connected to a first pipe to form an outdoor side circuit, wherein the first pipe is used to circulate a first working medium to the first heat exchanger, the compressor and the expansion mechanism, and the second heat exchanger is arranged indoors and is connected to a second pipe used to circulate a second working medium to the second heat exchanger to form an indoor side circuit, and the refrigeration device also includes a secondary heat exchanger, which is arranged between the first pipe and the second pipe and is used to exchange heat between the first working medium and the second working medium, and the secondary heat exchanger is arranged outdoors, the first working medium contains at least fluoroolefins, and the second working medium does not contain fluoroolefins.

[0025] According to the above structure, fluoroolefins that may undergo a disproportionation reaction are not used in the second working medium circulating in the indoor circuit, and fluoroolefins are used in the first working medium circulating in the outdoor circuit. In addition, a secondary heat exchanger capable of performing heat exchange between the indoor circuit and the outdoor circuit is arranged outdoors. Thus, even if a disproportionation reaction occurs in the fluoroolefin in the outdoor circuit and its influence spreads to the secondary heat exchanger, the influence can be limited to the outdoor equipment. Therefore, the influence of the disproportionation reaction can be effectively prevented from spreading to the indoor.

[0026] The refrigeration device having the above structure may further include a bypass pipe including a shutoff valve connected in parallel to the secondary heat exchanger in the first pipe, wherein the bypass pipe is provided outdoors.

[0027] In addition, in the refrigeration device of the above structure, the indoor side circuit may also include: a pump for pressurizing the second working medium to the second heat exchanger; and an indoor side inflow stop valve for cutting off the flow of the second working medium into the secondary heat exchanger, and the pump stops when the indoor side inflow stop valve cuts off the flow of the second working medium.

[0028] In the refrigeration device having the above structure, the indoor circuit may further include a gas-liquid separator connected to the second pipe and provided outdoors, and the gas-liquid separator may include a safety valve for releasing gas at a predetermined pressure.

[0029] Furthermore, in the refrigeration device having the above structure, the indoor circuit may further include an indoor outflow stop valve provided on an outflow side of the gas-liquid separator.

[0030] In addition, in the refrigeration device of the above structure, it may also include: a controller; and a first working medium temperature measuring device for measuring the temperature of the first working medium flowing in the first piping, and when the first working medium temperature measuring device reaches a specified temperature, the controller opens the stop valve included in the bypass piping.

[0031] In addition, in the refrigeration device of the above structure, it may also include: a controller; and a first working medium temperature measuring device for measuring the temperature of the first working medium flowing in the first piping, and the outdoor side circuit also includes an outdoor side circulation shut-off valve for cutting off the inflow and outflow of the first working medium to the secondary heat exchanger, and when the first working medium temperature measuring device reaches a specified temperature, the controller closes the outdoor side circulation shut-off valve and stops the operation of the outdoor side circuit.

[0032] In addition, in the refrigeration device having the above structure, the secondary heat exchanger may be any one of a plate heat exchanger, a double-tube heat exchanger, and a shell and tube heat exchanger.

[0033] Furthermore, in the refrigeration device having the above structure, the first working medium may be a mixed refrigerant containing propane in addition to the above fluoroolefin.

[0034] In addition, in the refrigeration device of the above structure, the first working medium may further contain a disproportionation inhibitor.

[0035] In addition, in the refrigeration device of the above structure, the second working medium may also be a liquid refrigerant or a low-pressure refrigerant.

[0036] Hereinafter, a representative embodiment of the present invention will be described with reference to the accompanying drawings. In addition, in the following, the same reference numerals are attached to the same or corresponding elements in all the drawings, and their repeated descriptions are omitted.

[0037] (Implementation Method 1)

[0038] (Configuration example of refrigeration device)

[0039] Figure 1 The refrigeration device R1 shown in FIG. 1 is a representative configuration example of the first embodiment, and the refrigeration device R1 is configured as an air conditioner. Figure 1 As shown, the refrigeration device R1 of Embodiment 1 is composed of an outdoor circuit 10 and an indoor circuit 20 .

[0040] like Figure 1 As shown in the dotted line frame, the outdoor circuit 10 includes a first pipe 11, a compressor 12, a first heat exchanger 13, a first fan 14, an expansion valve 15, a four-way valve 16, a secondary heat exchanger 30, etc. In addition, the indoor circuit 20 is similar to the outdoor circuit 10. Figure 1 As shown in the dotted line box, it includes a second pipe 21, a pump 22, a second heat exchanger 23, a second fan 24, a secondary heat exchanger 30, etc. Therefore, the secondary heat exchanger 30 is a structure belonging to the outdoor circuit 10 and the indoor circuit 20 (that is, both the outdoor circuit 10 and the indoor circuit 20 include the secondary heat exchanger 30).

[0041] In the outdoor circuit 10 , the compressor 12 , the secondary heat exchanger 30 , the expansion valve 15 , and the first heat exchanger 13 are connected in series by the first pipe 11 so as to circulate sequentially via the four-way valve 16 , thereby constituting one refrigeration cycle.

[0042] The first working medium containing at least fluoroolefin circulates in the outdoor circuit 10. The fluoroolefin contained in the first working medium is, for example, 1,1,2-trifluoroethylene (HFO1123) in the present embodiment 1, but there is no particular limitation. The first working medium may be a single refrigerant of only HFO1123, or a mixed refrigerant containing other refrigerant components in addition to HFO1123. The first working medium will be described in detail later.

[0043] The compressor 12 compresses the first working medium. The first heat exchanger 13 performs heat exchange between the first working medium and outdoor air (external air). The first fan 14 sends outdoor air to the first heat exchanger 13. The expansion valve 15 is an expansion mechanism that expands the first working medium.

[0044] The discharge side (i.e., the exhaust side) and the suction side of the compressor 12 are connected to the four-way valve 16, respectively. The four-way valve 16 changes the flow direction of the first working medium by switching it. If the discharge side of the compressor 12 is switched to the direction of the first heat exchanger 13, it becomes a cooling operation, and if the discharge side of the compressor 12 is switched to the direction of the secondary heat exchanger 30, it becomes a heating operation. The cooling operation and the heating operation will be described later. In addition, in Figure 1 In FIG. 1 , the flow direction of the first working medium during cooling operation is indicated by a black solid arrow F1 , and the flow direction of the first working medium during heating operation is indicated by a white hollow arrow F2 .

[0045] In the indoor circuit 20, the pump 22, the secondary heat exchanger 30, and the second heat exchanger 23 are connected in series by the second pipe 21 so as to circulate in sequence, thereby forming a refrigeration cycle. Figure 1 The thick dotted line shown is the dividing line between the indoor side and the outdoor side. Figure 1 As shown, in the indoor circuit 20, only the second heat exchanger 23 is arranged indoors, and the pump 22 and the secondary heat exchanger 30 are arranged outdoor. In addition, the pump 22 may also be arranged indoors. In addition, the outdoor circuit 10 is entirely arranged outdoor.

[0046] The second working medium that does not contain fluoroolefins circulates in the indoor side circuit 20. As long as the second working medium does not contain fluoroolefins, there is no particular limitation on its composition. For example, as the second working medium, a known liquid refrigerant or a low-pressure refrigerant can be preferably used. In the present embodiment 1, carbon dioxide (CO2) is used as the second working medium. As the liquid refrigerant, water or brine or antifreeze liquid with water as the main component can also be used. The second working medium will be described in detail later.

[0047] The pump 22 pressurizes the second working medium in the second pipe 21. The second heat exchanger 23 performs heat exchange between the second working medium and the indoor air. The second fan 24 delivers the indoor air to the second heat exchanger 23. The indoor circuit 20 does not include a structure such as the four-way valve 16 in the outdoor circuit 10. Therefore, in the indoor circuit 20, the second working medium circulates in only one direction. Figure 1 In FIG. 1 , the flow direction of the second working medium is indicated by a black solid arrow F3.

[0048] As described above, the secondary heat exchanger 30 is included in the outdoor circuit 10 and the indoor circuit 20. The secondary heat exchanger 30 performs heat exchange between the first working medium circulated in the outdoor circuit 10 and the second working medium circulated in the indoor circuit 20. Therefore, the outdoor circuit 10 and the indoor circuit 20 can be thermally connected via the secondary heat exchanger 30.

[0049] Thus, the refrigeration device R1 of the present invention is configured as a binary cycle via the secondary heat exchanger 30, which performs heat exchange between the first working medium and the second working medium. Thus, the outdoor circuit 10 and the indoor circuit 20, which are independent refrigeration cycles, can be cooperatively controlled in one refrigeration device R1.

[0050] In the present invention, there are no special restrictions on the specific structures of the compressor 12, the first heat exchanger 13, the first fan 14, the expansion valve 15, the four-way valve 16, the pump 22, the second heat exchanger 23, the second fan 24, and the secondary heat exchanger 30 that constitute the refrigeration device R1, and the structures known in the field of the refrigeration device R1 can be applied.

[0051] For example, a known sealed refrigerant compressor can be used as the compressor 12. The sealed refrigerant compressor may be any of a reciprocating type, a rotary type, a scroll type, a screw type, etc. In addition, the electric component of the refrigerant compressor may be an outer rotor type motor or an inner rotor type motor as long as it has the same structure as a known electric motor.

[0052] Since the first heat exchanger 13 is a heat exchanger on the "outdoor side", it can be considered as a "condenser" of a general refrigeration device. Similarly, since the second heat exchanger 23 is a heat exchanger on the "indoor side", it can be considered as an "evaporator" of a general refrigeration device. Therefore, a known heat exchanger can be used as a condenser as the first heat exchanger 13, and a known heat exchanger can be used as an evaporator as the second heat exchanger 23. As such a heat exchanger, for example, a plate heat exchanger, a shell and tube heat exchanger, a shell and tube heat exchanger, etc. can be cited, but there is no particular limitation.

[0053] The secondary heat exchanger 30 can also be a known heat exchanger like the first heat exchanger 13 or the second heat exchanger 23. In particular, the secondary heat exchanger 30 does not perform heat exchange between the working medium and the air (outdoor air or indoor air) like the first heat exchanger 13 or the second heat exchanger 23, but performs heat exchange between the first working medium and the second working medium. Therefore, the type of heat exchanger can be selected according to the types of the first working medium and the second working medium.

[0054] In the present invention, the first working medium is a refrigerant containing fluoroolefins. For example, if the second working medium is also a general refrigerant with hydrofluorocarbons (Hydrofluorocarbons) as the main component, a plate heat exchanger can be used. In addition, if the second working medium is a liquid refrigerant such as water, brine, antifreeze, etc., a shell and tube heat exchanger can be used. The shell and tube heat exchanger is a structure in which a plurality of inner tubes are arranged in an outer tube (shell) as a main body, and the second working medium of liquid refrigerant can flow through the inner tubes, and the first working medium containing fluoroolefins can flow through the outer tubes.

[0055] The expansion valve 15 may be a temperature automatic expansion valve, an electronic expansion valve, or other expansion mechanisms. The four-way valve 16, the pump 22, the first fan 14, the second fan 24, etc. may also be various known structures.

[0056] Next, the representative operation of the refrigeration device R1 is described. First, the cooling operation is described. In the outdoor circuit 10, the high-temperature and high-pressure first working medium compressed by the compressor 12 is sent to the first heat exchanger 13 (arrow F1 direction) via the four-way valve 16. In the first heat exchanger 13, the first working medium becomes a high-pressure and medium-temperature liquid by heat exchange with the outdoor air (external air) delivered by the first fan 14 and is sent to the expansion valve 15.

[0057] The first working medium is expanded in the expansion valve 15 to become a low-pressure, low-temperature gas-liquid mixed state and is sent to the secondary heat exchanger 30. In the secondary heat exchanger 30, heat is exchanged between the first working medium and the second working medium of the indoor circuit 20 to become a low-pressure, medium-temperature gas, which is sucked into the suction side of the compressor 12 through the four-way valve 16.

[0058] In the indoor circuit 20, the second working medium is pumped by the pump 22 and sent to the secondary heat exchanger 30 (arrow F3 direction). In the secondary heat exchanger 30, as described above, since heat exchange is performed between the first working medium and the second working medium, the second working medium is cooled by the low-temperature and low-pressure first working medium and sent to the second heat exchanger 23 provided indoors. In the second heat exchanger 23, heat exchange is performed with the indoor air sent by the second fan 24, and the indoor air is cooled by the second working medium, thereby cooling the room.

[0059] Next, the heating operation is described. In the outdoor circuit 10, the high-temperature and high-pressure first working medium compressed by the compressor 12 is sent to the secondary heat exchanger 30 (arrow F2 direction) via the four-way valve 16. In the secondary heat exchanger 30, heat exchange is performed between the first working medium and the second working medium of the indoor circuit 20, whereby the first working medium becomes a high-pressure, medium-temperature liquid and is sent to the expansion valve 15.

[0060] The first working medium expands in the expansion valve 15 to become a low-temperature and low-pressure gas-liquid mixed state and is then sent to the first heat exchanger 13. In the first heat exchanger 13, the first working medium exchanges heat with the outdoor air sent by the first fan 14, and becomes a low-pressure and medium-temperature gas and is sucked into the suction side of the compressor 12.

[0061] In the indoor circuit 20, the second working medium is pumped by the pump 22 and sent to the secondary heat exchanger 30. In the secondary heat exchanger 30, as described above, since heat exchange is performed between the first working medium and the second working medium, the second working medium is heated by the high-temperature and high-pressure first working medium and sent to the second heat exchanger 23 provided indoors. In the second heat exchanger 23, heat is exchanged with the indoor air sent by the second fan 24, and the indoor air is heated by the second working medium, thereby heating the room.

[0062] In the refrigeration device R1 of the present invention, a fluoroolefin with a lower GWP is used in the outdoor circuit 10. For example, in the first embodiment, HFO1123 is used as described above. Such a fluoroolefin has a low GWP, a high cooling capacity, and a performance close to that of the currently widely used R32. However, as described above, fluoroolefins are prone to disproportionation reactions. Since the disproportionation reaction is accompanied by a large amount of heat release, there is a problem that the disproportionation reaction proceeds in a chain reaction.

[0063] Therefore, in the refrigeration device R1 of the present invention, a refrigerant containing fluoroolefin is used as the first working medium circulating in the outdoor circuit 10, and a refrigerant other than fluoroolefin that may undergo a disproportionation reaction is used as the second working medium circulating in the indoor circuit 20. In addition, a secondary heat exchanger 30 capable of performing heat exchange between the outdoor circuit 10 and the indoor circuit 20 is provided outdoors.

[0064] Thus, even if the fluoroolefin undergoes a disproportionation reaction in the outdoor circuit 10 and its influence reaches the secondary heat exchanger 30, the influence is limited to the outdoor equipment. Therefore, it is possible to effectively prevent the influence of the disproportionation reaction from reaching the indoors.

[0065] In addition, as described later, in the present embodiment 1, the first working medium can use a mixed refrigerant containing propane in addition to the fluoroolefin. Propane not only has good physical properties as a working medium for a refrigeration cycle, but also has the effect of suppressing the disproportionation reaction of the fluoroolefin when used in combination with the fluoroolefin. Therefore, by making the first working medium containing the fluoroolefin a mixed refrigerant that also contains propane, the disproportionation reaction of the fluoroolefin can be suppressed well, while achieving good refrigeration capacity.

[0066] In addition, as described later, the first working medium may contain a disproportionation inhibitor in addition to the fluoroolefin. If the fluoroolefin in the first working medium is used as the first refrigerant component, propane is used as the second refrigerant component, but the first working medium may contain a disproportionation inhibitor as a component other than these refrigerant components. This can better suppress the disproportionation reaction of the fluoroolefin.

[0067] That is, since the first working medium contains fluoroolefin, it is necessary to take measures to prevent the disproportionation reaction of fluoroolefin in the outdoor circuit 10 where the first working medium circulates, but by containing propane or a disproportionation inhibitor or both in the first working medium, it is possible to more effectively suppress or actually prevent the disproportionation reaction from occurring in the outdoor circuit 10. In addition, as described later, the first working medium may contain other refrigerant components besides propane.

[0068] In addition, as the second working medium, as described above, a liquid refrigerant (brine) or a low-pressure refrigerant can also be used. The first working medium is a gas refrigerant mainly composed of fluorocarbons containing fluoroolefins, and the second working medium is a liquid refrigerant or a low-pressure refrigerant that is not subject to the Japanese High-Pressure Gas Safety Law. Therefore, even if a disproportionation reaction occurs in the outdoor circuit 10 where the first working medium circulates, the influence of the disproportionation reaction is difficult to affect the indoor circuit 20 where the second working medium circulates.

[0069] (Configuration Example of First Working Medium and Second Working Medium)

[0070] Next, the first working medium and the second working medium used in the refrigeration device R1 of the present invention will be described in detail.

[0071] First, the first working medium used in the outdoor circuit (10) may contain at least fluoroolefin (Fluoroalkene) as a refrigerant component. There is no particular limitation on the specific types of fluoroolefins, such as 1,1,2-trifluoroethylene (HFO1123), trans-1,2-difluoroethylene (HFO1132(E)), cis-1,2-difluoroethylene (HFO1132(Z)), 1,1-difluoroethylene (HFO1132a), tetrafluoroethylene (FO1114, TFE), monofluoroethylene (HFO1141) and other fluoroethylenes; 1,2,3,3,3-pentafluoropropylene (HFO-1225ye), 2,3,3,3-tetrafluoropropylene (HFO-1234yf), 1,3,3,3-tetrafluoropropylene (HFO-1234ze), 1,2,3,3-tetrafluoropropylene (HFO-1234ye), 3,3,3-trifluoropropylene (HFO-1243zf) and other fluoropropylenes; and the like.

[0072] These fluoroolefins may be used alone or in combination of two or more thereof as the refrigerant component. Among them, vinyl fluoride can be used as the refrigerant component, and among these vinyl fluorides, 1,1,2-trifluoroethylene (HFO1123) is particularly suitable.

[0073] In addition, the first working medium may also contain a refrigerant other than fluoroolefin as a refrigerant component. A representative example is propane. Therefore, as the first working medium, a mixed refrigerant of fluoroolefin and propane can be used. In addition, in the present invention, as the refrigerant component of the first working medium, it is also possible to contain "other refrigerant components" other than fluoroolefin and propane. Representative other refrigerants are not particularly limited, and hydrofluorocarbons (HFCs), saturated hydrocarbons other than propane, carbon dioxide, etc. can be listed.

[0074] Specific examples of HFCs include fluoromethanes such as difluoromethane (R32) and trifluoromethane (R23); fluoroethanes such as fluoroethane (R161), 1,1-difluoroethane (R152a), 1,1,1-trifluoroethane (R143a), 1,1,2,2-tetrafluoroethane (R134), 1,1,1,2-tetrafluoroethane (R134a), pentafluoroethane (R125), difluoroethane, and trifluoroethane; and fluoroethanes such as 1,1,1,3,3-pentafluoropropane (R245f a), 1,1,1,2,3,3-hexafluoropropane (R236ea), 1,1,1,3,3,3-hexafluoropropane (R236fa), 1,1,1,2,3,3,3-heptafluoropropane (R227ea) and other fluoropropanes; 1,1,1,3,3-pentafluorobutane (R365mfc) and other fluorobutanes; 1,1,1,2,3,4,4,5,5,5-decafluoropentane (R4310mee), heptafluorocyclopentane (Rc447ef) and other fluoropentanes; etc.

[0075] Specific examples of the saturated hydrocarbons include ethane, n-propane, cyclopropane, n-butane, cyclobutane, isobutane (2-methylpropane), methylcyclopropane, n-pentane, isopentane (2-methylbutane), neopentane (2,2-dimethylpropane), and methylcyclobutane.

[0076] These other refrigerant components can be used in one kind only, or two or more kinds can be appropriately combined and used as refrigerants. Among them, R32 (difluoromethane) can be typically applied. In addition, as described later, saturated hydrocarbons contain saturated hydrocarbons that can be used as disproportionation inhibitors. Therefore, saturated hydrocarbons can be used as other refrigerant components and disproportionation inhibitors at the same time.

[0077] In the present invention, it is known that the first working medium contains fluoroolefins and a disproportionation reaction occurs in the fluoroolefins. Therefore, the first working medium may also contain a disproportionation inhibitor that inhibits the disproportionation reaction of the fluoroolefins. There are no particular restrictions on the specific disproportionation inhibitor, and examples thereof include saturated hydrocarbons having 2 to 5 carbon atoms (but excluding propane), or halogenated alkanes having any one of 1 to 4 carbon atoms except for the case where all halogen atoms are fluorine. For the sake of convenience, the saturated hydrocarbons used as disproportionation inhibitors are referred to as "disproportionation inhibiting alkanes", and the halogenated alkanes used as disproportionation inhibitors are referred to as "disproportionation inhibiting halogenated alkanes".

[0078] As described above, the disproportionation suppressing alkane used as the disproportionation suppressing alkane in the present invention may be any saturated hydrocarbon (alkane) having 2 to 5 carbon atoms, and specifically, ethane, cyclopropane, n-butane, cyclobutane, isobutane (2-methylpropane), methylcyclopropane, n-pentane, isopentane (2-methylbutane), neopentane (2,2-dimethylpropane), methylcyclobutane, etc. These saturated hydrocarbons may be used alone or in combination of two or more thereof.

[0079] These saturated hydrocarbons are all gases at room temperature (the boiling points of n-pentane and methylcyclobutane are the highest at about 36°C, and the boiling points of other hydrocarbons are less than 36°C), and can be well mixed with the refrigerant component of the first working medium. Saturated hydrocarbons with more than 6 carbon atoms are liquids at room temperature, so they are difficult to mix with the refrigerant component of the first working medium, and are therefore not satisfactory.

[0080] In addition, propane, which is a saturated hydrocarbon having 3 carbon atoms, can suppress the disproportionation reaction of fluoroolefins. However, in the present invention, as described above, propane is a refrigerant component that can be used together with fluoroolefins as the first working medium, and therefore is not included in the "disproportionation-suppressing alkane". However, cyclic cyclopropane is different from linear propane (n-propane) as a refrigerant component, and therefore can be used as a disproportionation-suppressing alkane.

[0081] In addition, methane, a saturated hydrocarbon having 1 carbon atom, is not satisfactory because of its particularly large global warming potential (GWP). In addition, among saturated hydrocarbons having 2 to 5 carbon atoms, cyclopentane has a boiling point of 49° C. and is liquid at room temperature, but can be used as a disproportionation inhibitor in the present invention.

[0082] In the present invention, the disproportionation-inhibiting halogenated alkane used as the disproportionation inhibitor may be any one having 1 to 4 carbon atoms except when all halogen atoms are fluorine. More specifically, examples thereof include halogenated methane (halogenated methane) having 1 carbon atom, halogenated ethane (halogenated ethane) having 2 carbon atoms, halogenated propane (halogenated propane) having 3 carbon atoms, halogenated butane (halogenated butane) having 4 carbon atoms, and the like.

[0083] As the disproportionation-inhibited halogenated alkane, any one of methyl halide, ethyl halide, propyl halide and butyl halide can be used, but two or more of these disproportionation-inhibited halogenated alkanes can also be appropriately selected and used in combination. The selection of two or more mentioned here includes not only the case where two or more disproportionation-inhibited halogenated alkanes with different numbers of carbon atoms are selected (for example, a combination of any methyl halide and any methyl halide), but also the case where two or more disproportionation-inhibited halogenated alkanes with the same number of carbon atoms are selected (the types of substituted halogen atoms of the disproportionation-inhibited halogenated alkanes are different) (for example, a combination of a first ethyl halide and a second ethyl halide different therefrom). In addition, the butyl halide can be a straight-chain structure or a branched structure (i.e., a structure having the same carbon skeleton as isobutane or 2-methylpropane).

[0084] Specifically, the disproportionation-suppressed halogenated alkane may have a structure represented by the following molecular formula (1).

[0085] C p H q X r ……(1)

[0086] Wherein, X in the molecular formula (1) is a halogen atom selected from fluorine (F), chlorine (Cl), bromine (Br), and iodine (I), p is an integer of 1 or 2, q is an integer greater than 0, and r is an integer greater than 1, the sum of q and r is 2p+2, and when r is greater than 2, X is the same or different types of halogen atoms.

[0087] However, the disproportionation-reduced halogenated alkanes represented by the above molecular formula (1) exclude disproportionation-reduced halogenated alkanes in which X consists only of F. This is because the disproportionation-reduced halogenated alkanes in which X consists only of F are compounds that can be used in combination with other refrigerant components, but do not substantially function as disproportionation inhibitors.

[0088] In the disproportionation-suppressed halogenated alkane represented by the molecular formula (1), as described above, the halogen atom X only needs to be at least one of F, Cl, Br and I, but is preferably at least I. When the number of carbon atoms is 2 (p=2) and the number of halogen atoms is 2 or more (r≥2), the halogen atom X is preferably at least F and I.

[0089] When the disproportionation-inhibited halogenated alkane represented by the molecular formula (1) contains Cl and / or Br, the availability or operability may be limited due to the tendency of the ozone depletion potential (ODP) to increase. In addition, regardless of the type of the halogen atom X, the disproportionation-inhibited halogenated alkane represented by the molecular formula (1) also includes compounds having relatively large ozone depletion potential (ODP) and / or global warming potential (GWP).

[0090] However, in the present invention, even if the relative amount of the disproportionation-inhibiting halogenated alkane added as the disproportionation inhibitor to the first working medium is small, the disproportionation reaction of the fluoroolefin can be effectively inhibited or the rapid progress of the disproportionation reaction can be alleviated. In addition, even if the disproportionation-inhibiting halogenated alkane is used in combination with other disproportionation inhibitors such as disproportionation-inhibiting alkanes, the total amount of the disproportionation inhibitor added is sufficiently less than the total amount of the first working medium. Therefore, even if the disproportionation-inhibiting halogenated alkane having a relatively large ODP or GWP is used, there will be no significant impact on the environment.

[0091] The disproportionation-inhibited halogenated alkane represented by the molecular formula (1) is not particularly limited, and specific examples thereof include:

[0092] Iodomethane (CH3I), diiodomethane (CH2I2), dibromomethane (CH2Br2), bromomethane (CH3Br), dichloromethane (CH2Cl2), chloroiodomethane (CH2ClI), dibromochloromethane (CHBr2C1), tetraiodomethane (CI4), tetrabromocarbon (CBr4), bromotrichloromethane (CBrCl3), dibromodichloromethane (CBr2Cl2), tribromofluoromethane (CBr3F), diiodoform (CHFI 2), difluorodiiodomethane (CF2I2), dibromodifluoromethane (CBr2F2), trifluoroiodomethane (CF3I), difluoroiodomethane (CHF2I) and other halogenated ethanes; 1,1,1-trifluoro-2-iodoethane (CF3CH2I), iodoethane (CH3CH2I), bromoethane (CH3CH2Br), 1,1,1-triiodoethane (CH3CI3), 1-bromo-2-iodotetrafluoroethane (CF2BrCF2I) and other halogenated ethanes, etc.

[0093] These disproportionation-inhibiting halogenated alkanes may be used alone or in combination of two or more thereof. Among them, in consideration of availability, ODP value, operability, etc., at least one selected from diiodomethane (CH2I2), difluorodiiodomethane (CF2I2), trifluoroiodomethane (CF3I), difluoroiodomethane (CHF2l), 1-bromo-2-iodotetrafluoroethane (CF2BrCF2I), and 1,1,1-trifluoro-2-iodoethane (CF3CH2I) is particularly preferably used.

[0094] As described above, in the present invention, the first working medium is a refrigerant containing at least fluoroolefin (fluoroolefin), and may contain, for example, propane (R290) or other refrigerant components as required, and may also contain a disproportionation inhibitor. In such a first working medium, the content (content ratio) of fluoroolefin and propane or the content (content ratio) of the disproportionation inhibitor is not particularly limited.

[0095] For example, when the total amount of the first working medium is 100% by mass, the content of the fluoroolefin can be 50% by mass or more, 60% by mass or more, 70% by mass or more, or 80% by mass or more. In addition, if the first working medium is a mixed refrigerant containing propane, when the total amount of the mixed refrigerant is 100% by mass, the content of propane can be less than 50% by mass, 40% by mass or less, 30% by mass or less, or 20% by mass or less. In the first embodiment, as the fluoroolefin, for example, 1,1,2-trifluoroethylene (HFO1123) can be used, but there is no particular limitation.

[0096] The second working medium used in the refrigeration device R1 of the present invention is different from the first working medium, as long as it does not contain fluoroolefin (fluoroalkene) as a refrigerant component. In addition, the second working medium may not be a fluorocarbon refrigerant like the first working medium, for example, it may be a liquid refrigerant, or it may be a natural refrigerant other than a fluorocarbon refrigerant. Here, in the case where the second working medium is not a liquid refrigerant but a gas refrigerant such as a fluorocarbon refrigerant, a low-pressure refrigerant that is not subject to the Japanese High Pressure Gas Safety Law can be used.

[0097] When the second working medium is a fluorocarbon refrigerant, a refrigerant having a composition obtained by removing fluoroolefins from the first working medium can be used. If the second working medium is a natural refrigerant, ammonia, carbon dioxide (carbon dioxide gas), hydrocarbons, nitrogen, etc. can be used. Hydrocarbons include the above-mentioned propane or other saturated hydrocarbons.

[0098] When the second working medium is a liquid refrigerant such as brine, examples thereof include lower alcohols such as methanol and ethanol or aqueous antifreeze solutions containing them, lower glycols such as ethylene glycol and propylene glycol or aqueous antifreeze solutions containing them, and inorganic salt aqueous solutions such as calcium chloride aqueous solutions.

[0099] In this way, the first working medium is a gas refrigerant mainly composed of fluorocarbons containing fluoroolefins, and the second working medium is a liquid refrigerant or a low-pressure refrigerant that is not subject to the Japanese High Pressure Gas Safety Law. Thus, even if a disproportionation reaction occurs in the outdoor circuit 10 where the first working medium circulates, the influence of the disproportionation reaction is unlikely to affect the indoor circuit 20 where the second working medium circulates.

[0100] In addition, the first working medium and the second working medium may also contain additives or other components known in the field of refrigeration devices or refrigeration cycles. In addition, in the first working medium compressed by the compressor 12, as a component of the first working medium, the refrigeration oil contained in the compressor 12 may also be contained.

[0101] (Implementation Method 2)

[0102] Figure 2 The refrigeration device R2 shown is a representative structural example of the second embodiment. Figure 2 As shown, the refrigeration device R2 of the second embodiment is constituted by an outdoor circuit 10 and an indoor circuit 20 similarly to the refrigeration device R2 of the first embodiment, and is thermally connected via a secondary heat exchanger 30 .

[0103] like Figure 2 As shown, the refrigeration device R2 of this embodiment 2 has the same basic structure as the refrigeration device R1 of the above-mentioned embodiment 1, and the first working medium circulating in the outdoor circuit 10 and the second working medium circulating in the indoor circuit 20 are also the same as those of the above-mentioned embodiment 1. Therefore, the detailed description of the structure of the refrigeration device R2 of this embodiment 2 that is common to the refrigeration device R1 of the above-mentioned embodiment 1 is omitted.

[0104] The refrigeration device R2 of the second embodiment is different from that of the first embodiment in that Figure 2 As shown, the outdoor circuit 10 further includes a bypass pipe 17 including a shutoff valve 31 connected in parallel with the secondary heat exchanger 30 in the first pipe 11. In addition, the indoor circuit 20 is different from the first embodiment in that, when viewed from the secondary heat exchanger 30, the indoor circuit 20 includes a gas-liquid separator 25 having a safety valve 26 connected to the second pipe on the downstream side (in the direction of arrow F3) of the flow direction of the second working medium.

[0105] In addition, there are differences in that, in the outdoor circuit 10 and the indoor circuit 20, stop valves 32 to 35 are provided at the upstream and downstream sides of the flow direction of the first working medium or the second working medium when viewed from the secondary heat exchanger 30. In addition, the bypass pipe 17 and the gas-liquid separator 25 are both as shown in FIG. Figure 2 Setup shown is outdoors.

[0106] The bypass pipe 17 included in the outdoor circuit 10 is connected to the first pipe 11 in parallel with the secondary heat exchanger 30 between the four-way valve 16 and the expansion valve 15. As described above, the bypass pipe 17 is connected to the first pipe 11 in parallel with the secondary heat exchanger 30. As described above, the bypass pipe stop valve 31 is provided in the bypass pipe 17. In addition, the first pipe 11 is provided with outdoor flow stop valves 32 and 33 at both sides of the secondary heat exchanger 30 (at positions sandwiching the secondary heat exchanger 30).

[0107] One outdoor flow stop valve 32 is located between the secondary heat exchanger 30 and the four-way valve 16. Another outdoor flow stop valve 33 is located between the secondary heat exchanger 30 and the expansion valve 15. The first heat exchanger 13 is located between the four-way valve 16 and the expansion valve 15.

[0108] In the outdoor circuit 10 , as described in Embodiment 1, the compressor 12 is connected to the first pipe 11 via the four-way valve 16 , and the flow direction of the first working medium is changed by switching the four-way valve 16 .

[0109] In cooling operation, the first working medium compressed by the compressor 12 is sent to the first heat exchanger 13 (arrow F1 direction) via the four-way valve 16, and therefore, when viewed from the secondary heat exchanger 30, the first working medium flows in via the first heat exchanger 13 and the expansion valve 15. On the other hand, in heating operation, the first working medium compressed by the compressor 12 is sent to the secondary heat exchanger 30 (arrow F2 direction) via the four-way valve 16.

[0110] Therefore, in cooling operation, the outdoor circulation stop valve 32 becomes a stop valve on the inflow side and the outdoor circulation stop valve 33 becomes a stop valve on the outflow side when viewed from the secondary heat exchanger 30, and in heating operation, the outdoor circulation stop valve 33 becomes a stop valve on the inflow side and the outdoor circulation stop valve 32 becomes a stop valve on the outflow side when viewed from the secondary heat exchanger 30. Therefore, in the second embodiment, the outdoor circulation stop valves 32 and 33 are positioned as valves for blocking the inflow and outflow of the first working medium relative to the secondary heat exchanger 30, and neither valve is defined as the inflow side or the outflow side.

[0111] The bypass pipe stop valve 31 is normally closed, and the outdoor circulation stop valves 32 and 33 are normally opened. Therefore, when the outdoor circuit 10 is normally operated, the first working medium flows through the secondary heat exchanger 30. On the other hand, if the bypass pipe stop valve 31 is opened and the outdoor circulation stop valves 32 and 33 are closed, the first working medium flows between the four-way valve 16 and the expansion valve 15 without passing through the secondary heat exchanger 30 (bypassing the secondary heat exchanger 30).

[0112] In this way, if the bypass pipe 17 is provided in the outdoor circuit 10 where the secondary heat exchanger 30 is located, and the bypass pipe 17 has the bypass pipe stop valve 31, it is possible to switch between allowing the first working medium containing fluoroolefin to flow through the secondary heat exchanger 30 or allowing the first working medium to circulate in the outdoor circuit 10 while bypassing the secondary heat exchanger 30. Thus, even if the disproportionation reaction of fluoroolefin occurs in the outdoor circuit 10, the influence on the secondary heat exchanger 30 can be further suppressed, and the influence on the indoor environment can be more effectively avoided.

[0113] Furthermore, by providing the outdoor flow stop valves 32 and 33 that block the inflow and outflow of the first working medium to the secondary heat exchanger 30, when the disproportionation reaction of the fluoroolefin occurs in the outdoor circuit 10, the flow of the first working medium to the secondary heat exchanger 30 can be stopped. Thus, the possibility of the influence of the disproportionation reaction spreading to the secondary heat exchanger 30 can be more effectively suppressed, and further, the influence of the disproportionation reaction can be more effectively suppressed from spreading to the indoor circuit 20 via the secondary heat exchanger 30.

[0114] In addition, the opening and closing of the bypass pipe stop valve 31 and the opening and closing of the outdoor circulation stop valves 32 and 33 may or may not be linked. For example, when the first working medium is allowed to flow only in the bypass pipe 17 and the flow of the first working medium to the secondary heat exchanger 30 is stopped, the bypass pipe stop valve 31 may be opened and the outdoor circulation stop valves 32 and 33 may be closed. On the contrary, even when the first working medium is allowed to flow in the bypass pipe 17, these stop valves 31 to 33 do not need to be linked as long as the flow to the secondary heat exchanger 30 is not hindered. At this time, the opening and closing of the outdoor circulation stop valves 32 and 33 may also be linked.

[0115] Alternatively, when it is not necessary to make the first working medium flow in a roundabout way to the bypass pipe 17, and it is sufficient that the first working medium does not flow to the secondary heat exchanger 30, these stop valves 31 to 33 do not need to be linked, and the outdoor flow stop valves 32 and 33 can be closed. Alternatively, when it is desired to only stop the outflow of the first working medium from the secondary heat exchanger 30, or conversely, when it is desired to only stop the inflow of the first working medium into the secondary heat exchanger 30, the outdoor flow stop valves 32 and 33 do not need to be linked.

[0116] When viewed from the secondary heat exchanger 30, the gas-liquid separator 25 included in the indoor circuit 20 is located on the downstream side of the flow direction of the second working medium. Figure 2 In the illustrated structure, the pump 22, the secondary heat exchanger 30, the gas-liquid separator 25, and the second heat exchanger 23 are connected to the second pipe 21 so as to circulate in this order.

[0117] In addition, the second pipe 21 is provided with an indoor inflow stop valve 34 on the inflow side of the second working medium (the upstream side in the flow direction of the second working medium) when viewed from the secondary heat exchanger 30. The indoor inflow stop valve 34 is normally open, but when closed, it is linked to the operation of the pump 22. That is, when the indoor inflow stop valve 34 is closed and the inflow of the second working medium into the secondary heat exchanger 30 is cut off, the pump 22 stops.

[0118] In addition, the second pipe 21 is provided with an indoor outlet stop valve 35 on the outflow side of the second working medium (downstream side in the flow direction of the second working medium) when viewed from the gas-liquid separator 25. The indoor outlet stop valve 35 is also normally open.

[0119] The indoor circuit 20 includes a gas-liquid separator 25, so that even if the first working medium flows into the indoor circuit 20 in the secondary heat exchanger 30, the first working medium mixed with the second working medium can be separated by the gas-liquid separator 25. In addition, since the gas-liquid separator 25 is arranged outdoors, the first working medium that flows in can be released outdoors at a predetermined pressure by the safety valve 26. Thus, even if a disproportionation reaction of fluoroolefin occurs in the outdoor circuit 10 and its influence has spread to the secondary heat exchanger 30, it is possible to more effectively prevent the influence from spreading indoors.

[0120] In addition, by providing an indoor outflow stop valve 35 on the outflow side of the second working medium when viewed from the gas-liquid separator 25, for example, even if the first working medium flows into the indoor circuit 20 in the secondary heat exchanger 30 and reaches the gas-liquid separator 25, by closing the indoor outflow stop valve 35, it is possible to prevent the first working medium from flowing into the indoor circuit 20 via the gas-liquid separator 25. Thus, even if the influence of the disproportionation reaction spreads from the secondary heat exchanger 30 to the gas-liquid separator 25, it is possible to more effectively prevent the influence from spreading to the room.

[0121] Furthermore, by providing the indoor inflow stop valve 34 on the inflow side of the second working medium when viewed from the secondary heat exchanger 30, even if the fluoroolefin undergoes a disproportionation reaction in the outdoor circuit 10, the indoor inflow stop valve 34 is closed in the indoor circuit 20, so that the inflow of the second working medium into the secondary heat exchanger 30 can be stopped, and as described above, the pump 22 is also stopped. Thus, the influence of the disproportionation reaction on the secondary heat exchanger 30 can be further suppressed, and the influence on the room can be more effectively prevented.

[0122] The specific structure of the stop valves 31 to 35 is not particularly limited, and any control valve known in the field of refrigeration devices can be used. Typically, gate valves or ball valves with excellent on / off performance for fluids such as refrigerants can be used, but other known control valves can also be used as needed.

[0123] The specific structure of the gas-liquid separator 25 is not particularly limited, and a known structure can be applied. For example, in the general field of refrigerants, surface tension type or centrifugal force type structures are known, so these methods can be applied. In this embodiment 2, as a representative gas-liquid separator 25, an oil separator type or a method using a tank (for the sake of convenience, referred to as an "oil separator type") is used.

[0124] As such an oil separator type gas-liquid separator 25, for example, the structures described in the patent gazettes of the Japanese patent applications previously applied by the present applicant, such as Patent No. 6264688, Patent No. 6497582, and Patent No. 6555584, can be cited. In addition, the contents of these Japanese patent gazettes are cited as a reference in this specification and are made a part of the contents of this specification.

[0125] Such an oil separator type gas-liquid separator 25 includes, for example, a tank as a volume body having a space of a predetermined volume inside, a gas pipe and an inlet pipe connected to the upper portion of the tank, and an outlet pipe connected to the lower portion of the tank.

[0126] If the refrigerant flowing into the tank is, for example, a refrigerant in which liquid refrigerant and gas refrigerant are in a mixed state (liquid-gas mixed refrigerant), the liquid-gas mixed refrigerant flows into the interior of the tank from the top of the tank via the inlet pipe, is separated by being temporarily stored in the tank, and the liquid refrigerant flows out from the outlet pipe at the bottom of the tank, and the gas refrigerant flows out from the gas pipe at the top of the tank.

[0127] For example, the second working medium circulating in the indoor side circuit 20 is a liquid refrigerant. In the secondary heat exchanger 30, when the first working medium containing fluoroolefins is mixed with the second working medium, the second working medium of the liquid refrigerant and the first working medium of the gaseous refrigerant can be separated by temporarily storing them in a tank.

[0128] Alternatively, when the second working medium is a gas refrigerant and the first working medium (gas refrigerant) is mixed with the second working medium (gas refrigerant), the mixed refrigerants can be expanded by using an expansion valve, so that one of the gas refrigerants can be easily evaporated, and then temporarily stored in a tank, and the pressure in the tank is adjusted to separate it into a liquid refrigerant and a gas refrigerant. At this time, when the separated liquid refrigerant is circulated as a gas refrigerant, for example, a liquid piping can be set separately from the outlet piping. The liquid piping is connected to the expansion valve, and the expansion valve is used to throttle and expand the liquid refrigerant, thereby returning it to the second piping 21 as a gas refrigerant again.

[0129] In addition, in the second embodiment, the refrigeration device R2 may also be configured to include the bypass pipe 17 and the stop valves 31 to 33, but not the gas-liquid separator 25 and the stop valves 34 and 35. Alternatively, the refrigeration device R2 may also be configured to include the gas-liquid separator 25 and the stop valves 34 and 35, but not the bypass pipe 17 and the stop valves 31 to 33.

[0130] Alternatively, in the refrigeration device R2 of the second embodiment, it is also possible to have a structure that does not include one or more of the shutoff valves 31 to 35. For example, in the indoor circuit 20, it is also possible to include only the indoor inflow stop valve 34 without including the indoor outflow stop valve 35, or it is also possible to include only the indoor outflow stop valve 35 without including the indoor inflow stop valve 34.

[0131] (Implementation method 3)

[0132] Figure 3 The refrigeration device R3 shown in FIG. 1 is a representative structural example of the refrigeration device R3 of the third embodiment. Figure 3 As shown, the refrigeration device R3 of the present Embodiment 3 is constituted by an outdoor circuit 10 and an indoor circuit 20 similarly to the refrigeration device R1 of the above-mentioned Embodiment 1 and the refrigeration device R2 of the above-mentioned Embodiment 2, and is thermally connected via a secondary heat exchanger 30 .

[0133] A more specific structure of the refrigeration device R3 (including the first working medium and the second working medium) has been described in the above-mentioned Embodiment 1 or Embodiment 2. Therefore, in the refrigeration device R3 of the present Embodiment 3, a detailed description of the structure common to the refrigeration device R1 or the refrigeration device R2 is omitted.

[0134] In the refrigeration device R3 of the third embodiment, Figure 3 As shown, the difference from the first or second embodiment is that a temperature sensor 41 (a temperature measuring device for the first working medium) for measuring (detecting) the temperature of the first working medium flowing in the first pipe is included. Figure 3 As shown, the flow temperature of the first working medium measured by the temperature sensor 41 is used for controlling the control unit 40 .

[0135] In the refrigeration device R1 of the first embodiment or the refrigeration device R2 of the second embodiment, the control is also performed by the control unit 40. However, in the third embodiment, in order to explain that the control unit 40 uses the detection result of the temperature sensor 41 to control, Figure 3 The control unit 40 is shown in the figure, and the control signal is schematically represented by a dotted arrow.

[0136] The control unit 40 controls the operation of the refrigeration device R3 (the refrigeration device R1 of the first embodiment or the refrigeration device R2 of the second embodiment is also controlled by the control unit 40). Therefore, the control unit 40 also controls the compressor 12, the four-way valve 16, the pump 22, the first fan 14 and the second fan 24, etc., but Figure 3In the third embodiment, if the control unit 40 determines that the temperature of the first working medium measured (detected) by the temperature sensor 41 has reached a predetermined temperature, the control unit 40 controls the bypass pipe stop valve 31 of the bypass pipe 17 to be opened.

[0137] That is, the control unit 40 continuously monitors the temperature of the first working medium containing fluoroolefin using the temperature sensor 41, and if it is determined that the temperature has reached a predetermined temperature, the bypass pipe shutoff valve 31 is opened to allow the first working medium to flow into the bypass pipe 17. As described above, the disproportionation reaction of fluoroolefin is considered to be induced by factors such as high pressure and heat, and when the disproportionation reaction occurs, a large amount of heat is released. Therefore, the temperature of the first working medium can be used as a direct reference for determining the occurrence of the disproportionation reaction or the risk of the disproportionation reaction.

[0138] Therefore, by controlling the bypass pipe stop valve 31 according to the measurement result of the temperature sensor 41, the first working medium is allowed to flow to the bypass pipe 17 in a circuitous manner, so that the influence of the disproportionation reaction on the secondary heat exchanger 30 can be further suppressed, and the influence on the room can be more effectively avoided. At this time, as described in the above-mentioned embodiment 2, the outdoor side flow stop valves 32 and 33 can also be opened by controlling the closing of the bypass pipe stop valve 31 in conjunction with the closing of the bypass pipe stop valve 31.

[0139] Alternatively, if it is determined based on the measurement result of the temperature sensor 41 that the temperature of the first working medium has reached a predetermined temperature, the control unit 40 controls to close the outdoor flow stop valves 32 and 33 and stop the operation of the outdoor circuit 10. This can further suppress the influence of the disproportionation reaction from affecting the secondary heat exchanger 30, and can also suppress the chain of disproportionation reaction in the outdoor circuit 10. If the operation of the outdoor circuit 10 is stopped in this way, the outdoor circuit 10 does not need to have the bypass pipe 17.

[0140] Furthermore, the control unit 40 may execute control to close the indoor inflow stop valve 34 included in the indoor circuit 20 and stop the operation of the indoor circuit 20 in cooperation with control to open the bypass pipe stop valve 31 or control to close the outdoor flow stop valves 32 and 33 and stop the operation of the outdoor circuit 10. Thus, the influence of the disproportionation reaction on the indoor circuit 20 can be further suppressed.

[0141] In Embodiment 3, even if the controller 40 closes the outdoor flow stop valves 32 and 33 and does not allow the first working medium to flow into the secondary heat exchanger 30 , there is no need to perform operation stop control of the outdoor circuit 10 or the indoor circuit 20 .

[0142] For example, even if the control unit 40 controls to close the outdoor circulation stop valves 32 and 33 based on the measurement result of the temperature sensor 41, as long as the bypass pipe stop valve 31 is controlled to be opened, the first working medium can be prevented from flowing into the secondary heat exchanger 30. Therefore, control can be performed such that the first working medium flows through the bypass pipe 17 while the operation of the outdoor circuit 10 is continued, and when the measurement result of the temperature sensor 41 is lower than the specified temperature, the outdoor circulation stop valves 32 and 33 are opened.

[0143] Alternatively, the control unit 40 may continue to operate the indoor circuit 20 even if the outdoor circulation stop valves 32 and 33 are closed to stop the operation of the outdoor circuit 10, based on the measurement result of the temperature sensor 41. In this case, for example, the indoor inflow stop valve 34 may be kept open, the indoor outflow stop valve 35 may be closed, and the first working medium (or the product produced by the disproportionation reaction, etc.) contained in the second working medium may be removed in the gas-liquid separator 25.

[0144] The specific structure of the temperature sensor 41 is not particularly limited, and a temperature measuring device known in the field of refrigeration devices can be used. Representatively, a temperature sensor of a resistance temperature measuring body, a thermocouple temperature sensor, a thermistor, etc. can be listed, but there is no particular limitation. The installation position of the temperature sensor 41 relative to the first pipe 11 is also not particularly limited, as long as it is a position that can well measure the temperature of the first working medium, but representatively, a position (a pipe connected to the discharge side of the compressor 12) that can measure the temperature of the first working medium discharged from the compressor 12 can be cited.

[0145] There is no particular restriction on the specific structure of the control unit 40, and a known general structure can be applied. Specifically, the control unit 40 is constituted as hardware, and the hardware includes integrated circuits (ICs) such as various processors, ASIC (Application Specific Integrated Circuit), FPGA (Field Programmable Gate Array), and CPLD (Complex Programmable Logic Device). These hardware can also be circuits including active components (transistors, etc.) and passive components (capacitors, resistors, etc.). The integrated circuit may include a memory, and may also include a memory such as a volatile memory (RAM) or a non-volatile memory (ROM) outside the integrated circuit. The control program for executing the above-mentioned control, the data required for executing the control program, and other software can be stored in the memory. Therefore, the control unit 40 is composed of a combination of hardware and software, and the software can also constitute the control unit 40 together with the hardware.

[0146] In addition, the present invention is not limited to the above-mentioned embodiments, and various changes can be made within the scope indicated by the claims. Embodiments obtained by appropriately combining technical means respectively described in different embodiments or multiple modified examples are also included in the technical scope of the present invention.

[0147] In addition, according to the above description, many improvements and other embodiments of the present invention are obvious to those skilled in the art. Therefore, the above description should be interpreted as only examples, and is provided to guide those skilled in the art to implement the preferred mode of the present invention. Without departing from the purpose of the present invention, the details of its structure and / or function can be substantially changed.

[0148] (Note)

[0149] Based on the description of each embodiment above, the following technology is described in this specification.

[0150] (Technology 1)

[0151] A refrigeration device, comprising a first heat exchanger, a second heat exchanger, a compressor and an expansion mechanism, wherein the first heat exchanger, the compressor and the expansion mechanism are arranged outdoors and connected to a first pipe to form an outdoor side circuit, wherein the first pipe is used to circulate a first working medium to the first heat exchanger, the compressor and the expansion mechanism, and the second heat exchanger is arranged indoors and connected to a second pipe used to circulate a second working medium to the second heat exchanger to form an indoor side circuit, and the refrigeration device also includes a secondary heat exchanger, which is arranged between the first pipe and the second pipe and is used to exchange heat between the first working medium and the second working medium, and the secondary heat exchanger is arranged outdoors, the first working medium contains at least fluoroolefins, and the second working medium does not contain fluoroolefins.

[0152] (Technique 2)

[0153] The refrigeration device according to the first technique further includes a bypass pipe including a shutoff valve connected in parallel to the secondary heat exchanger in the first pipe, the bypass pipe being installed outdoors.

[0154] (Technique 3)

[0155] A refrigeration device as described in Technology 1 or 2, wherein the indoor circuit includes: a pump for pressurizing the second working medium to the second heat exchanger; and an indoor inflow stop valve for cutting off the flow of the second working medium into the secondary heat exchanger, and the pump stops when the indoor inflow stop valve cuts off the flow of the second working medium.

[0156] (Technique 4)

[0157] A refrigeration device as described in any one of techniques 1 to 3, wherein the indoor circuit further includes a gas-liquid separator connected to the second pipe and arranged outdoors, and the gas-liquid separator includes a safety valve that releases gas at a specified pressure.

[0158] (Technique 5)

[0159] As described in Technology 4, the indoor side circuit further includes an indoor side outflow stop valve arranged on the outflow side of the gas-liquid separator.

[0160] (Technique 6)

[0161] A refrigeration device as described in any one of Techniques 2 to 5, which further includes: a controller; and a first working medium temperature measuring device for measuring the temperature of the first working medium flowing in the first piping, wherein the controller opens the stop valve included in the bypass piping when the first working medium temperature measuring device reaches a specified temperature.

[0162] (Technique 7)

[0163] A refrigeration device as described in any one of Techniques 2 to 5, which further includes: a controller; and a first working medium temperature measuring device for measuring the temperature of the first working medium flowing in the first piping, the outdoor circuit also includes an outdoor circulation shut-off valve for cutting off the inflow and outflow of the first working medium to the secondary heat exchanger, and the controller closes the outdoor circulation shut-off valve and stops the operation of the outdoor circuit when the first working medium temperature measuring device reaches a specified temperature.

[0164] (Technology 8)

[0165] A refrigeration device as described in any one of Techniques 1 to 7, wherein the secondary heat exchanger is any one of a plate heat exchanger, a shell and tube heat exchanger, and a shell and tube heat exchanger.

[0166] (Technique 9)

[0167] A refrigeration device as described in Technology 8, wherein the first working medium is a mixed refrigerant containing propane in addition to the fluoroolefin.

[0168] (Technology 10)

[0169] A refrigeration device as described in any one of Techniques 1 to 8, wherein the first working medium further contains a disproportionation inhibitor.

[0170] (Technology 11)

[0171] A refrigeration device as described in Technology 8 or 9, wherein the second working medium is liquid refrigerant or low-pressure refrigerant.

[0172] Industrial Applicability

[0173] The present invention can be widely applied to the field of refrigeration devices, particularly to the field of refrigeration devices using a working medium containing fluoroolefins in a refrigeration cycle including a compressor.

[0174] Description of Reference Numerals

[0175] 10: Outdoor circuit

[0176] 11: First piping

[0177] 12: Compressor

[0178] 13: First heat exchanger

[0179] 14: First fan

[0180] 15: Expansion valve (expansion mechanism)

[0181] 16: Four-way valve

[0182] 17: Bypass piping

[0183] 20: Indoor side circuit

[0184] 21: Second piping

[0185] 22: Pump

[0186] 23: Second heat exchanger

[0187] 24: Second fan

[0188] 25: Gas-liquid separator

[0189] 26: Safety valve

[0190] 30: Secondary heat exchanger

[0191] 31: Bypass piping stop valve

[0192] 32: Outdoor flow stop valve

[0193] 33: Outdoor flow stop valve

[0194] 34: Indoor side inflow stop valve

[0195] 35: Indoor outflow stop valve

[0196] 40: Control unit (controller)

[0197] 41: Temperature sensor (first working medium temperature measuring device)

[0198] F1, F2: Flow direction of the first working medium

[0199] F3: Flow direction of the second working medium

[0200] R1: Refrigeration unit

[0201] R2: Refrigeration unit

[0202] R3: Refrigeration unit.

Claims

1. A refrigeration device, characterized in that: comprising a first heat exchanger, a second heat exchanger, a compressor and an expansion mechanism, The first heat exchanger, the compressor, and the expansion mechanism are arranged outdoors and connected to a first pipe to form an outdoor circuit, wherein the first pipe is used to circulate a first working medium to the first heat exchanger, the compressor, and the expansion mechanism. The second heat exchanger is disposed indoors and is connected to a second pipe for circulating a second working medium to the second heat exchanger to form an indoor circuit. The refrigeration device further includes a secondary heat exchanger, which is disposed between the first pipe and the second pipe and is used to perform heat exchange between the first working medium and the second working medium. The secondary heat exchanger is arranged outdoors. The first working medium contains at least fluoroolefin, and the second working medium does not contain fluoroolefin.

2. The refrigeration device according to claim 1, characterized in that: further comprising a bypass pipe including a shutoff valve connected in parallel to the secondary heat exchanger in the first pipe, The bypass pipe is installed outdoors.

3. The refrigeration device according to claim 1 or 2, characterized in that: The indoor circuit includes: a pump for pressurizing the second working medium to the second heat exchanger; and an indoor inflow stop valve for blocking the inflow of the second working medium into the secondary heat exchanger. When the chamber inner inflow shutoff valve shuts off the inflow of the second working medium, the pump stops.

4. The refrigeration device according to claim 1 or 2, characterized in that: The indoor circuit further includes a gas-liquid separator connected to the second pipe and arranged outdoors. The gas-liquid separator includes a safety valve that releases gas at a specified pressure.

5. The refrigeration device according to claim 4, characterized in that: The indoor circuit further includes an indoor outflow stop valve disposed on the outflow side of the gas-liquid separator.

6. The refrigeration device according to claim 2, characterized in that: further comprising: a controller; and a first working medium temperature measuring device for measuring the temperature of the first working medium flowing in the first pipe, The controller opens the shutoff valve included in the bypass pipe when the temperature of the first working medium temperature measuring device reaches a predetermined temperature.

7. The refrigeration device according to claim 2, characterized in that: further comprising: a controller; and a first working medium temperature measuring device for measuring the temperature of the first working medium flowing in the first pipe, The outdoor circuit further includes an outdoor flow stop valve for blocking the inflow and outflow of the first working medium to the secondary heat exchanger. The controller closes the outdoor flow shutoff valve and stops the operation of the outdoor circuit when the temperature of the first working medium temperature measuring device reaches a predetermined temperature.

8. The refrigeration device according to claim 1 or 2, characterized in that: The secondary heat exchanger is any one of a plate heat exchanger, a double-tube heat exchanger, and a shell and tube heat exchanger.

9. The refrigeration device according to claim 8, characterized in that: The first working medium is a mixed refrigerant containing propane in addition to the fluoroolefin.

10. The refrigeration device according to claim 1 or 2, characterized in that: The first working medium further contains a disproportionation inhibitor.

11. The refrigeration device according to claim 8 or 9, characterized in that: The second working medium is liquid refrigerant or low-pressure refrigerant.

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