Refrigeration cycle device

Abstract

The present disclosure provides a refrigeration cycle device in which an operating medium containing an ethylene-based fluoroolefin is injected without coming into contact with a motor unit of a compressor, thereby making it possible to improve system performance while suppressing a disproportionation reaction.　A refrigeration cycle device according to the present disclosure uses an operating medium including an ethylene-based fluoroolefin, and comprises a compressor, an outdoor heat exchanger, an indoor heat exchanger, and an intermediate pressure receiver, wherein: the refrigeration cycle device is provided with an injection pipe for feeding the operating medium from the intermediate pressure receiver to a compressing unit within the compressor; and the operating medium injected from the injection pipe into the compressor is compressed by the compressor and then discharged directly to the outside of the compressor.

Description

Refrigeration Cycle Equipment

[0001] The present disclosure relates to a refrigeration cycle device.

[0002] Patent Document 1 discloses a technology in which a means-side compression mechanism and a high-stage-side compressor bore are housed and installed within a sealed housing, refrigerant gas compressed by the low-stage-side compression mechanism is discharged into the sealed housing, intermediate-pressure refrigerant gas in the sealed housing is sucked into the high-stage-side compression mechanism, and injection refrigerant from an injection circuit is discharged into the sealed housing.

[0003] JP 2008-144643 A

[0004] The present disclosure provides a refrigeration cycle device that can improve system performance while suppressing disproportionation reactions by injecting a working medium containing an ethylene-based fluoroolefin without contacting the motor part of the compressor.

[0005] The refrigeration cycle device according to the present disclosure uses a working fluid containing an ethylene-based fluoroolefin, and includes a compressor, an outdoor heat exchanger, an indoor heat exchanger, and an oil separator. The refrigeration cycle device also includes an injection pipe that sends the working fluid from the oil separator to a compression section in the compressor. The working fluid injected from the injection pipe into the compressor is compressed by the compressor and then directly discharged to the outside of the compressor. This specification includes the entire contents of Japanese Patent Application No. 2023-169475, filed on September 29, 2023.

[0006] According to the refrigeration cycle device of the present disclosure, the working medium injected from the injection pipe is compressed by the compressor and then directly discharged to the outside of the compressor without being discharged into the compressor, thereby preventing the working medium from accumulating inside the compressor. Therefore, the ethylene-based fluoroolefin-based working medium can be injected without coming into contact with the motor of the compressor, thereby improving system performance while suppressing the disproportionation reaction.

[0007] FIG. 1 is a schematic diagram showing the overall configuration of a refrigeration cycle device according to a first embodiment; FIG. 2 is a schematic diagram showing a compressor according to the first embodiment; FIG. 3 is a schematic diagram showing the overall configuration of a refrigeration cycle device according to a second embodiment; FIG. 4 is a schematic diagram showing a compressor according to a third embodiment; and FIG. 5 is a schematic diagram of a refrigeration cycle device according to a modified example of the present disclosure.

[0008] (Knowledge, etc., that Formed the Basis of the Present Disclosure) At the time the inventors arrived at the present disclosure, conventional refrigeration cycle devices housed a means-side compression mechanism and a high-pressure compression mechanism in a sealed housing. Refrigerant gas compressed by the low-pressure compression mechanism was discharged into the sealed housing, intermediate-pressure refrigerant gas in the sealed housing was drawn into the high-pressure compression mechanism, and refrigerant injected from an injection circuit was discharged into the sealed housing. However, when injection is performed in a refrigeration cycle device using a refrigerant containing a fluorocarbon that has the property of causing a disproportionation reaction, the injected refrigerant is discharged into the compressor sealed housing, and comes into contact with the motor, which may cause a layer short, potentially resulting in a disproportionation reaction. Therefore, the inventors discovered a problem in that the conventional configuration was unable to ensure safety by suppressing disproportionation reactions while improving system performance through injection. To solve this problem, the present disclosure was conceived. Therefore, the present disclosure provides a refrigeration cycle device that can improve system performance while suppressing disproportionation reactions by injecting a working medium containing an ethylene-based fluoroolefin without it coming into contact with the motor part of the compressor.

[0009] Hereinafter, embodiments will be described in detail with reference to the drawings. However, unnecessary detailed description may be omitted. For example, detailed description of already well-known matters or redundant description of substantially the same configuration may be omitted. Note that the accompanying drawings and the following description are provided to enable those skilled in the art to fully understand the present disclosure, and are not intended to limit the subject matter described in the claims.

[0010] (Embodiment 1) [1-1. Configuration] [1-1-1. Overall Configuration of Refrigeration Cycle Apparatus] FIG. 1 is a schematic diagram showing the overall configuration of a refrigeration cycle apparatus 1 in Embodiment 1. As shown in FIG. 1, the refrigeration cycle apparatus 1 includes an outdoor unit 10 and an indoor unit 20. The outdoor unit 10 and the indoor unit 20 are connected via a refrigerant pipe 11 to form a refrigerant circuit through which a refrigerant circulates. The refrigeration cycle apparatus 1 uses a working fluid containing an ethylene-based fluoroolefin in the refrigeration cycle circuit. Many ethylene-based fluoroolefins are characterized by low GWP. However, it is known that ethylene-based fluoroolefins can undergo disproportionation reactions when exposed to electrical discharges under high temperature and high pressure. The occurrence of a disproportionation reaction can cause a sudden increase in pressure within the refrigeration cycle circuit. Details of the working fluid will be described later.

[0011] The outdoor unit 10 includes a compressor 12, an outdoor heat exchanger 13, an outdoor expansion valve 14, and an intermediate pressure receiver 15. The compressor 12 is, for example, a rotary compressor that draws in, compresses, and discharges a gaseous working medium. The outdoor heat exchanger 13 is, for example, a fin-tube heat exchanger that drives an outdoor fan (not shown) to exchange heat between the working medium flowing therein and external air. The outdoor expansion valve 14 is a valve whose opening degree can be changed and reduces the pressure of the working medium passing through it. The intermediate pressure receiver 15 separates and stores oil from the refrigerant.

[0012] One end of an injection pipe 16 is connected to the intermediate pressure receiver 15. The other end of the injection pipe 16 is connected to the compressor 12, and is configured so that the working medium inside the intermediate pressure receiver 15 can be injected from the injection pipe 16 into the compressor 12. An injection expansion valve 17 is provided in the middle of the injection pipe 16.

[0013] The indoor unit 20 includes an indoor heat exchanger 21 and an indoor expansion valve 22. The indoor heat exchanger 21 is, for example, a fin-tube type heat exchanger, and drives an indoor fan (not shown) to exchange heat between the working medium flowing inside and the indoor air. The indoor expansion valve 22 is a valve whose opening and closing and opening degree can be changed.

[0014] [1-1-2. Compressor Configuration] FIG. 2 is a schematic diagram showing the compressor according to the first embodiment. As shown in FIG. 2, the compressor 12 is an internal intermediate-pressure multi-stage compression rotary compressor. A drive motor 31 is housed in the upper interior portion of a cylindrical casing 30 made of steel plate. A low-pressure side compression mechanism 32 and a high-pressure side compression mechanism 33 driven by the drive motor 31 are housed in the lower interior portion of the casing 30. The low-pressure side compression mechanism 32 is provided with a low-pressure side suction port 34 and a low-pressure side discharge port 35, and is configured to compress a low-pressure refrigerant to an intermediate pressure. The high-pressure side compression mechanism 33 is provided with a high-pressure side suction port 36 and a high-pressure side discharge port 37, and is configured to compress an intermediate-pressure refrigerant to a high pressure. The interior of the casing 30 is maintained at an intermediate pressure.

[0015] A low-pressure side discharge port 35 of the compressor 12 is connected to a high-pressure side suction port 36 of the compressor 12 via an intermediate pipe 38. A high-pressure side discharge port 37 of the compressor 12 is connected to the outdoor heat exchanger 13 via a refrigerant pipe 11.

[0016] [1-1-3. Working Medium] The working medium used in the air conditioner 1 is a working medium containing a fluoroolefin (fluoroalkene) such as an ethylene-based fluoroolefin. The specific type of fluoroolefin is not particularly limited, but examples include 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), etc. fluoroethylene; 1,2,3,3,3-pentafluoropropene (HFO-1225ye), 2,3,3,3-tetrafluoropropene (HFO-1234yf), 1,3,3,3-tetrafluoropropene (HFO-1234ze), 1,2,3,3-tetrafluoropropene (HFO-1234ye), 3,3,3-trifluoropropene (HFO-1243zf), and the like.

[0017] The working fluid may contain two or more refrigerant components. That is, it may contain a fluoroolefin selected from the examples above (e.g., 1,1,2-trifluoroethylene) and a second refrigerant component. The second refrigerant component may be, but is not limited to, a hydrofluorocarbon (HFC), a hydrofluoroolefin (HFO), a saturated hydrocarbon, carbon dioxide, or another refrigerant.

[0018] Examples of the hydrofluorocarbon include fluoromethanes such as difluoromethane (R32) and trifluoromethane (R23), 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), fluoroethanes such as difluoroethane and trifluoroethane, and 1,1,1,3,3-pentafluoropropane ( fluoropropanes such as 1,1,1,2,3,3-hexafluoropropane (R245fa), 1,1,1,2,3,3-hexafluoropropane (R236ea), 1,1,1,3,3,3-hexafluoropropane (R236fa), and 1,1,1,2,3,3,3-heptafluoropropane (R227ea); fluorobutanes such as 1,1,1,3,3-pentafluorobutane (R365mfc); and fluoropentanes such as 1,1,1,2,3,4,4,5,5,5-decafluoropentane (R4310mee) and heptafluorocyclopentane (Rc447ef).

[0019] Examples of 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, but other hydrocarbons may also be used. The second refrigerant component may contain multiple components. That is, the second refrigerant component may contain two or more refrigerant components selected from hydrofluorocarbons, hydrofluoroolefins, saturated hydrocarbons, carbon dioxide, and other refrigerants.

[0020] The working medium may be a refrigerant classified as mildly flammable (A2L), flammable (A2), or highly flammable (A3) according to ISO 817.

[0021] [1-1-4. Disproportionation Inhibitor] The working fluid used as a refrigerant in the air conditioner 1 may contain a disproportionation inhibitor in addition to the refrigerant components. The disproportionation inhibitor is, for example, a saturated hydrocarbon. The working fluid may contain a disproportionation inhibitor consisting of one or more components. Examples of saturated hydrocarbons used as disproportionation inhibitors include ethane, n-propane, cyclopropane, n-butane, cyclobutane, isobutane (2-methylpropane), methylcyclopropane, n-pentane, isopentane (2-methylbutane), neopentane (2,2-dimethylpropane), and methylcyclobutane, but other saturated hydrocarbons may also be used. A particularly preferred disproportionation inhibitor is n-propane.

[0022] The disproportionation inhibitor may be, for example, a haloalkane having 1 to 4 carbon atoms. The haloalkane used as the disproportionation inhibitor may be any haloalkane having 1 to 4 carbon atoms, excluding cases where all of the halogen atoms are fluorine. More specific examples include halomethanes (halogenated methanes) having 1 carbon atom, haloethanes (halogenated ethanes) having 2 carbon atoms, halopropanes (halogenated propanes) having 3 carbon atoms, and halobutanes (halogenated butanes) having 4 carbon atoms.

[0023] Specifically, the disproportionation-inhibiting haloalkane may be one having the structure of formula (1) shown below: CpHqXr (1)

[0024] However, X in formula (1) is a halogen atom selected from the group consisting of fluorine (F), chlorine (Cl), bromine (Br), and iodine (I). p is an integer of either 1 or 2. q is an integer of 0 or greater. r is an integer of 1 or greater. The sum of q and r is 2p+2. When r is 2 or greater, X are the same or different halogen atoms.

[0025] However, the disproportionation-inhibited haloalkanes represented by formula (1) above exclude those in which X is composed solely of F. This is because disproportionation-inhibited haloalkanes in which X is composed solely of F are compounds that can be used in combination with other refrigerant components, but do not substantially function as disproportionation inhibitors.

[0026] In the disproportionation-inhibited haloalkane represented by formula (1), the halogen atom X may be at least one of F, Cl, Br, and I, as described above, 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 greater (r≧2), the halogen atom X is preferably at least F and I.

[0027] The disproportionation-inhibiting haloalkane represented by formula (1) is not particularly limited, and specific examples thereof include (mono)iodomethane (CH3I), diiodomethane (CH2I2), dibromomethane (CH2Br2), bromomethane (CH3Br), dichloromethane (CH2Cl2), chloroiodomethane (CH2ClI), dibromochloromethane (CHBr2Cl), tetraiodomethane (CI4), carbon tetrabromide (CBr4), bromotrichloromethane (CBrCl3), dibromodichloromethane (CBr2Cl2), tribromofluoromethane (CBr3F), fluorodiiodomethane (CHFI), and the like. ), difluorodiiodomethane (CF2I2), dibromodifluoromethane (CBr2F2), trifluoroiodomethane (CF3I), and other halomethanes; 1,1,1-trifluoro-2-iodoethane (CF3CH2I), monoiodoethane (CH3CH2I), monobromoethane (CH3CH2Br), 1,1,1-triiodoethane (CH3CI3), 1-bromo-2-iodotetrafluoroethane (CF2BrCF2I), and other halomethanes.

[0028] The working fluid may contain a plurality of disproportionation inhibitors selected from the saturated hydrocarbons and haloalkanes. The working fluid may contain one type of saturated hydrocarbon, or two or more types of saturated hydrocarbons. The working fluid may contain one type of haloalkane, or two or more types of haloalkanes.

[0029] A preferred example of the working fluid is a mixture containing 1,1,2-trifluoroethylene and n-propane. This working fluid may contain the second refrigerant component described above, or may contain other components.

[0030] Each of the above working fluids may contain inevitable impurities, such as various additives including stabilizers added for the purpose of stabilizing the fluid during transportation or storage, residues or by-products of the raw materials used to synthesize the refrigerant components, and substances that are mixed in for other reasons.

[0031] The mass ratio of 1,1,2-trifluoroethylene to n-propane contained in the working fluid can be changed as appropriate. Thus, the contents (contents) of the fluoroolefin and other refrigerants, or the content (contents) of the disproportionation inhibitor in the mixed refrigerant are not particularly limited. For example, when the total amount of the mixed refrigerant is taken as 100% by mass, the fluoroolefin content may be 50% by mass or more, 60% by mass or more, 70% by mass or more, or even 80% by mass or more. Furthermore, when the total amount of the mixed refrigerant is taken as 100% by mass, the propane content may be less than 50% by mass, and may be 40% by mass or less, 30% by mass or less, or 20% by mass or less.

[0032] [1-2. Operation] Next, the operation of the first embodiment will be described. In this embodiment, the compressor 12 is driven to compress the working medium and discharge it toward the outdoor heat exchanger 13. The high-temperature, high-pressure working medium compressed by the compressor 12 exchanges heat with outdoor air in the outdoor heat exchanger 13, where it is condensed, and is expanded by the outdoor expansion valve 14. The working medium is then sent to the indoor expansion valve 22 via the intermediate pressure receiver 15, where it is further expanded and sent to the indoor heat exchanger 21. The working medium exchanges heat with indoor air in the indoor heat exchanger 21, cools the indoor air, and is then returned to the compressor 12. This series of operations enables cooling of the room.

[0033] In this case, by opening the injection expansion valve 17 of the injection pipe 16, the working medium stored in the intermediate-pressure receiver 15 is sent to the high-pressure-side suction port 36 of the compressor 12 via the injection pipe 16. The working medium sent from the injection pipe 16 to the high-pressure-side suction port 36 of the compressor 12 is compressed by the high-pressure-side compression mechanism 33 and then discharged toward the outdoor heat exchanger 13. In other words, the working medium sent from the injection pipe 16 is discharged to the outside of the compressor 12 without being discharged into the casing 30, which is in an intermediate-pressure state. As a result, the working medium injected from the injection pipe 16 is compressed by the high-pressure-side compression mechanism 33 and then directly discharged to the outside of the compressor 12 without being discharged inside the compressor 12, thereby preventing the working medium from accumulating within the compressor 12.

[0034] [1-3. Effects, etc.] As described above, the refrigeration cycle apparatus 1 of this embodiment uses a working fluid containing an ethylene-based fluoroolefin, and includes the compressor 12, the outdoor heat exchanger 13, the indoor heat exchanger, and the intermediate-pressure receiver 15. The refrigeration cycle apparatus 1 also includes the injection pipe 16 that sends the working fluid from the intermediate-pressure receiver 15 to a compression section in the compressor 12. The working fluid injected from the injection pipe 16 into the compressor 12 is compressed by the compressor 12 and then directly discharged to the outside of the compressor 12. As a result, the working fluid injected from the injection pipe 16 is compressed by the compressor 12 and then directly discharged to the outside of the compressor 12 without being discharged inside the compressor 12, which makes it possible to prevent the working fluid from accumulating in the compressor 12. Therefore, the ethylene-based fluoroolefin-based working fluid can be injected without coming into contact with the motor section of the compressor 12, thereby improving system performance while suppressing disproportionation reactions.

[0035] Furthermore, in the refrigeration cycle apparatus 1 of this embodiment, the compressor 12 is equipped with a two-stage compression mechanism having a low-pressure side and a high-pressure side, and an injection pipe 16 is connected to an intake pipe that draws the working medium discharged from the low-pressure side compression mechanism into the high-pressure side compression mechanism. As a result, after being compressed by the compressor 12, the working medium injected from the injection pipe 16 is discharged directly to the outside of the compressor 12 without being discharged into the compressor 12, thereby preventing the working medium from accumulating within the compressor 12. Therefore, the ethylene-based fluoroolefin-based working medium can be injected without coming into contact with the motor part of the compressor 12, thereby improving system performance while suppressing disproportionation reactions.

[0036] Second Embodiment Next, a second embodiment of the present disclosure will be described. [2-3. Configuration] Fig. 3 is a schematic diagram showing the overall configuration of a refrigeration cycle apparatus 1 according to the second embodiment. As shown in Fig. 3, in this embodiment, the compressor 12 is configured with two compressors 12: a low-pressure side compressor 12a and a high-pressure side compressor 12b. The low-pressure side compressor 12a is provided with a low-pressure side suction port 34 and a low-pressure side discharge port 35, and the high-pressure side compressor 12b is provided with a high-pressure side suction port 36 and a high-pressure side discharge port 37. The low-pressure side discharge port 35 of the low-pressure side compressor 12a and the high-pressure side suction port 36 of the high-pressure side compressor 12b are connected via an intermediate pipe 38. The intermediate pipe 38 is connected to the injection pipe 16.

[0037] [2-2. Operation] Next, the operation of embodiment 2 will be described. In this embodiment, as in embodiment 1, the working medium sent from the injection pipe 16 to the high-pressure side suction port 36 of the high-pressure side compressor 12b is compressed by the high-pressure side compressor 12b and then discharged toward the indoor heat exchanger 21. As a result, the working medium injected from the injection pipe 16 is compressed by the high-pressure side compressor 12b and then directly discharged to the outside of the high-pressure side compressor 12b, so that it is possible to prevent the working medium from accumulating within the compressor 12.

[0038] [2-3. Effects, etc.] As described above, in the refrigeration cycle apparatus 1 of this embodiment, the compressor 12 is composed of the low-pressure side compressor 12a and the high-pressure side compressor 12b, and the injection pipe 16 is connected to the intermediate pipe 38 that draws the working fluid discharged from the low-pressure side compressor 12a into the high-pressure side compressor 12b. As a result, after being compressed by the high-pressure side compressor 12b, the working fluid injected from the injection pipe 16 is discharged directly to the outside of the high-pressure side compressor 12b without being discharged into the high-pressure side compressor 12b, thereby preventing the working fluid from accumulating within the compressor 12. Therefore, the ethylene-based fluoroolefin-based working fluid can be injected without coming into contact with the motor unit of the compressor 12, thereby improving system performance while suppressing the disproportionation reaction.

[0039] Third Embodiment Next, a third embodiment of the present disclosure will be described. FIG. 4 is a schematic diagram showing a compressor according to the third embodiment. As shown in FIG. 4, an intermediate pipe 38 that connects a low-pressure side compression mechanism 32 and a high-pressure side compression mechanism 33 of the compressor 12 is connected to an injection pipe 16. In this embodiment, a mixer 40 is provided at the connection between the intermediate pipe 38 and the injection pipe 16. The mixer 40 mixes the working medium sent from the intermediate pipe 38 and the working medium sent from the injection pipe 16 to homogenize the concentrations of the working mediums. Since the other configurations are the same as those of the first embodiment, the same parts are designated by the same reference numerals and description thereof will be omitted.

[0040] [3-2. Operation] Next, the operation of the third embodiment will be described. In this embodiment, by opening the injection expansion valve 17 of the injection pipe 16, the working medium stored in the intermediate-pressure receiver 15 is sent to the high-pressure-side suction port 36 of the compressor 12 via the injection pipe 16. At this time, the working medium sent from the injection pipe 16 is mixed with the working medium sent from the intermediate pipe 38 in the mixer 40, and the working medium is sent to the high-pressure-side compression mechanism 33 with a uniform concentration. This makes it possible to prevent the working medium from becoming locally concentrated. The working medium sent from the mixer 40 to the high-pressure-side suction port 36 of the compressor 12 is compressed by the high-pressure-side compression mechanism 33 and then discharged toward the outdoor heat exchanger 13. In other words, the working medium sent from the injection pipe 16 is discharged to the outside of the compressor 12 without being discharged into the casing 30, which is in an intermediate-pressure state. As a result, after the working medium injected from the injection pipe 16 is compressed by the high-pressure side compression mechanism 33, it is discharged directly to the outside of the compressor 12 without being discharged inside the compressor 12, thereby preventing the working medium from stagnating inside the compressor 12.

[0041] [3-3. Effects, etc.] As described above, the refrigeration cycle apparatus 1 of this embodiment includes the mixing section 40 that mixes the working medium inside the compressor 12 with the working medium injected from the intermediate pressure receiver 15, and the working medium discharged from the mixing section 40 is drawn into the compression section of the compressor 12. As a result, the working medium sent from the injection pipe 16 and the working medium sent from the intermediate pipe 38 are mixed in the mixing section 40, and the working medium is sent to the high-pressure side compression mechanism 33 in a state where the concentration of the working medium is uniform, thereby preventing the working medium from becoming locally concentrated. Therefore, even if the ethylene-based fluoroolefin-based working medium comes into contact with the motor section of the compressor 12, the concentration can be kept low, and system performance can be improved while suppressing disproportionation reactions.

[0042] (Modification) Figure 5 is a schematic diagram of a refrigeration cycle apparatus 1 showing a modification of the present disclosure. As shown in Figure 5, the compressor 12 is configured with two compressors 12, a low-pressure side compressor 12a and a high-pressure side compressor 12b, and an injection pipe 16 is connected to an intermediate pipe 38 that connects the low-pressure side compressor 12a and the high-pressure side compressor 12b. A mixing section 40 is provided at the connection between this intermediate pipe 38 and the injection pipe 16. With this configuration, it is possible to obtain the same functions and effects as the above-described embodiment.

[0043] (Other Embodiments) As described above, Embodiments 1 to 3 have been described as examples of the technology disclosed in the present application. However, the technology in the present disclosure is not limited to these and can be applied to embodiments in which modifications, substitutions, additions, omissions, etc. are made. Furthermore, it is also possible to combine the components described in Embodiments 1 to 3 above to create new embodiments.

[0044] For example, an oil separator may be provided between the compressor 12 and the outdoor heat exchanger 13, and the oil separated by the oil separator may be returned to the compressor 12. In this case, the working medium is directly discharged from the compressor 12 to the outside of the compressor 12, thereby increasing the amount of oil discharged. The large amount of oil discharged to the outside of the compressor 12 can be recovered by the oil separator and returned to the compressor 12. This ensures that the oil is supplied to the sliding parts of the compressor 12 and that the oil does not remain inside the refrigeration cycle apparatus 1, thereby further improving the system performance while reliably suppressing the disproportionation reaction.

[0045] [Configurations Supported by the Above-described Embodiments] The above-described embodiments support the following configurations.

[0046] (Additional Notes) (Technology 1) A refrigeration cycle device using a working fluid containing an ethylene-based fluoroolefin, comprising a compressor, an outdoor heat exchanger, an indoor heat exchanger, and an intermediate-pressure receiver, and further comprising an injection pipe for sending the working fluid from the intermediate-pressure receiver to a compression section within the compressor, wherein the working fluid injected from the injection pipe into the compressor is compressed by the compressor and then directly discharged to the outside of the compressor. According to this configuration, the working fluid injected from the injection pipe is compressed by the compressor and then directly discharged to the outside of the compressor without being discharged inside the compressor, thereby preventing the working fluid from accumulating within the compressor. Therefore, the ethylene-based fluoroolefin-based working fluid can be injected without coming into contact with the motor section of the compressor, thereby improving system performance while suppressing disproportionation reactions.

[0047] (Technology 2) The refrigeration cycle apparatus according to Technology 1, wherein the compressor includes a two-stage compression mechanism having a low-pressure side and a high-pressure side, and the injection pipe is connected to a suction pipe that draws the working medium discharged from the low-pressure side compression mechanism into the high-pressure side compression mechanism. According to this configuration, after being compressed by the compressor, the working medium injected from the injection pipe is discharged directly to the outside of the compressor without being discharged inside the compressor, thereby preventing the working medium from accumulating inside the compressor. Therefore, the ethylene-based fluoroolefin-based working medium can be injected without coming into contact with the motor of the compressor, thereby improving system performance while suppressing disproportionation reactions.

[0048] (Technology 3) The refrigeration cycle apparatus according to Technology 2 further includes a mixing section that mixes the working medium inside the compressor with the working medium injected from the intermediate-pressure receiver, and the working medium discharged from the mixing section is drawn into the compression section of the compressor. According to this configuration, the working medium sent from the injection pipe and the working medium sent from the intermediate pipe are mixed in the mixing section, and the working medium is sent to the high-pressure compression mechanism in a homogenized state, thereby preventing the working medium from becoming locally highly concentrated. Therefore, even if the ethylene-based fluoroolefin-based working medium comes into contact with the motor section of the compressor, the concentration can be kept low, thereby improving system performance while suppressing disproportionation reactions.

[0049] (Technology 4) The refrigeration cycle device according to any one of Technologies 1 to 3, wherein the working fluid is a mixture of multiple types of working fluids, and includes at least one working fluid with a boiling point higher than that of the ethylene-based fluoroolefin. This configuration makes it easier to separate the ethylene-based fluoroolefin with a low boiling point as a gas in the intermediate-pressure receiver, and the separated ethylene-based fluoroolefin is injected into the compressor. This prevents the ethylene-based fluoroolefin, which carries a risk of causing a disproportionation reaction, from flowing into the compressor. This makes it possible to reliably suppress the disproportionation reaction while improving system performance.

[0050] (Technology 5) The refrigeration cycle apparatus according to any one of Technologies 1 to 4, further comprising an oil separator provided between the compressor and the outdoor heat exchanger, and wherein oil separated by the oil separator is returned to the compressor. According to this configuration, a large amount of oil discharged to the outside of the compressor can be recovered by the oil separator and returned to the compressor. Therefore, the oil can be reliably supplied to the sliding parts of the compressor, and oil does not remain inside the refrigeration cycle apparatus 1. This further improves system performance while reliably suppressing disproportionation reactions.

[0051] The present disclosure is suitable for use in a refrigeration cycle device that can improve system performance while suppressing disproportionation reactions by injecting a working fluid containing an ethylene-based fluoroolefin without contacting the motor part of the compressor.

[0052] REFRIGERATION CYCLE DEVICE 10 OUTDOOR UNIT 11 REFRIGERANTE PIPE 12 COMPRESSOR 12a LOW-PRESSURE SIDE COMPRESSOR 12b HIGHER-PRESSURE SIDE COMPRESSOR 13 OUTDOOR HEAT EXCHANGER 14 OUTDOOR EXPANSION VALVE 15 INTERMEDIATE-PRESSURE RECEIVER 16 INJECTION PIPE 17 INJECTION EXPANSION VALVE 20 INDOOR UNIT 21 INDOOR HEAT EXCHANGER 22 INDOOR EXPANSION VALVE 30 CASING 31 DRIVE MOTOR 32 LOW-PRESSURE SIDE COMPRESSION MECHANISM 33 HIGHER-PRESSURE SIDE COMPRESSION MECHANISM 34 LOW-PRESSURE SIDE SUPPLY 35 LOW-PRESSURE SIDE SUPPLY 36 HIGHER-PRESSURE SIDE SUPPLY 37 HIGHER-PRESSURE SIDE SUPPLY 38 INTERMEDIATE PIPE 40 MIXING SECTION

Claims

1. A refrigeration cycle device that uses a working medium containing an ethylene-based fluoroolefin, and is equipped with a compressor, an outdoor heat exchanger, an indoor heat exchanger, and an intermediate pressure receiver, and is equipped with an injection pipe that sends the working medium from the intermediate pressure receiver to a compression section in the compressor, and the working medium injected from the injection pipe into the compressor is compressed in the compressor and then directly discharged outside the compressor.

2. The refrigeration cycle device according to claim 1, wherein the compressor is provided with a two-stage compression mechanism having a low pressure side and a high pressure side, and the injection pipe is connected to a suction pipe that draws the working medium discharged from the low pressure side compression mechanism into the high pressure side compression mechanism.

3. A refrigeration cycle device as described in claim 2, further comprising a mixing section that mixes the working medium inside the compressor with the working medium injected from the intermediate pressure receiver, and the working medium discharged from the mixing section is sucked into a compression section of the compressor.

4. A refrigeration cycle device according to any one of claims 1 to 3, wherein the working medium is a mixture of a plurality of types of working medium, and includes at least a working medium having a boiling point higher than that of the ethylene-based fluoroolefin.

5. The refrigeration cycle apparatus according to claim 4, further comprising: an oil separator provided between said compressor and said outdoor heat exchanger; and oil separated by said oil separator being returned to said compressor.

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