Compressor and refrigeration cycle system

Abstract

In the present invention, a motor unit of a compressor is provided with a plurality of passages whereby an upper space and a lower space inside a sealed container are in communication. A is defined as the total cross-sectional area of all passages (rotor passages) provided to a rotor of the motor unit, B is defined as the total cross-sectional area of all passages (non-rotor passages) not provided to the rotor, C is defined as the total heat transfer area of all rotor passages, D is defined as the total heat transfer area of all non-rotor passages, and S is defined as the cross-sectional area of the sealed container based on the inner diameter thereof. In the compressor, A≥B, C≥D, the ratio C / S is not less than 1.0 (C / S≥1.0), or the ratio (A+B) / S is not less than 0.05 ((A+B) / S≥0.05). Thus, propagation of a disproportionation reaction of hydrofluoroolefin is favorably suppressed or mitigated without a large effect on the configuration of the compressor.

Description

Compressor and refrigeration cycle system

[0001] The present invention relates to a compressor that uses a working fluid for a refrigeration cycle containing at least a hydrofluoroolefin as a refrigerant component and that can effectively suppress or mitigate the disproportionation reaction of hydrofluoroolefins, and a refrigeration cycle system using the compressor.

[0002] Recently, the use of hydrofluoroolefins (HFOs), which have a lower global warming potential (GWP), has been proposed as working fluids (refrigerants or heat transfer media) for refrigeration cycles. A typical example of a hydrofluoroolefin is 1,1,2-trifluoroethylene (HFO1123). 1,1,2-trifluoroethylene is less stable than conventional HFCs and therefore less likely to remain in the atmosphere, and therefore has a smaller ODP and GWP.

[0003] It is known that such hydrofluoroolefins are prone to undergo a self-decomposition reaction called a disproportionation reaction and a polymerization reaction following this self-decomposition reaction (hereinafter referred to as a disproportionation reaction) due to their low stability. It is also known that the disproportionation reaction is prone to occur due to heat generated during use of the working fluid for a refrigeration cycle, and that since the occurrence of the disproportionation reaction is accompanied by a large heat release, the disproportionation reaction may occur in a chain reaction and propagate within the compressor.

[0004] Therefore, for example, Patent Document 1 proposes a configuration in which a metal heat absorption part is provided inside the compressor in order to suppress the propagation of the disproportionation reaction.

[0005] Specific examples of heat absorption parts include metal members arranged around the moving parts of the compressor (e.g., the motor or crankshaft), metal members arranged around the inside of the terminal pin (inner pin), and metal members constituting the compressor itself (e.g., the casing). In the compressor described in Patent Document 1, even if a disproportionation reaction occurs in the hydrofluoroolefin contained in the refrigerant, these heat absorption parts absorb the heat generated by the disproportionation reaction. This prevents an excessive temperature rise in the refrigerant and inhibits the propagation of the disproportionation reaction.

[0006] Japanese Patent Application Laid-Open No. 2022-027634

[0007] However, in the compressor described in Patent Document 1, the installation of the heat absorption section is limited to a configuration in which an additional heat absorption section is provided to the compressor, which results in an insufficient heat capacity of the heat absorption section, making it impossible to effectively absorb the heat of the disproportionation reaction generated in the hydrofluoroolefin, and thus making it impossible to effectively suppress the propagation of the disproportionation reaction.

[0008] The present invention has been made to solve these problems, and an object of the present invention is to effectively suppress or mitigate the propagation of the disproportionation reaction of hydrofluoroolefins without being significantly affected by the configuration of the compressor.

[0009] In order to solve the above-mentioned problems, the compressor according to the present disclosure is a compressor that uses a working fluid for a refrigeration cycle that contains at least a hydrofluoroolefin as a refrigerant component, and includes an electric motor unit having a rotor and a stator, a compression mechanism unit driven by the electric motor unit, and a sealed container that houses the electric motor unit and the compression mechanism unit inside, wherein spaces are provided above and below the electric motor unit within the sealed container, and the electric motor unit is provided with a plurality of passages that communicate with the upper space and the lower space, and wherein when the total cross-sectional area of ​​all the passages provided in the rotor is A and the total cross-sectional area of ​​all the passages provided other than the rotor is B, A≧B is satisfied.

[0010] Furthermore, in order to solve the above-mentioned problems, the compressor according to the present disclosure is a compressor that uses a working fluid for a refrigeration cycle that contains at least a hydrofluoroolefin as a refrigerant component, and includes an electric motor unit having a rotor and a stator, a compression mechanism unit driven by the electric motor unit, and a sealed container that houses the electric motor unit and the compression mechanism unit inside, wherein spaces are provided above and below the electric motor unit within the sealed container, and the electric motor unit is provided with a plurality of passages that communicate with the upper space and the lower space, and wherein the heat transfer area of ​​the passages is the product of the equivalent diameter d of the passages, the passage length L, and pi (π) (π × d × L), where C is the total heat transfer area of ​​all the passages provided in the rotor, and D is the total heat transfer area of ​​all the passages provided other than the rotor, and C is a configuration such that C≧D.

[0011] Furthermore, in order to solve the above-mentioned problems, the compressor according to the present disclosure is a compressor that uses a working fluid for a refrigeration cycle that contains at least a hydrofluoroolefin as a refrigerant component, and includes an electric motor unit having a rotor and a stator, a compression mechanism unit driven by the electric motor unit, and a sealed container that houses the electric motor unit and the compression mechanism unit inside, wherein spaces are provided above and below the electric motor unit within the sealed container, and the electric motor unit is provided with a plurality of passages that communicate with the upper space and the lower space, and wherein the heat transfer area of ​​the passages is the product of the equivalent diameter d of the passage, the passage length L, and pi (π × d × L), the total heat transfer area of ​​all the passages provided in the rotor is C, and the cross-sectional area of ​​the sealed container based on the inner diameter of the sealed container is S, so that the ratio C / S of the total heat transfer area C to the cross-sectional area S is 1.0 or greater (C / S≧1.0).

[0012] Furthermore, in order to solve the above-mentioned problems, the compressor according to the present disclosure is a compressor that uses a working fluid for a refrigeration cycle that contains at least a hydrofluoroolefin as a refrigerant component, and includes an electric motor unit having a rotor and a stator, a compression mechanism unit driven by the electric motor unit, and a sealed container that houses the electric motor unit and the compression mechanism unit, wherein spaces are provided above and below the electric motor unit within the sealed container, and the electric motor unit is provided with a plurality of passages that communicate the upper space with the lower space, and wherein a total cross-sectional area of ​​all the passages provided in the rotor is A, a total cross-sectional area of ​​all the passages provided other than the rotor is B, and further, a cross-sectional area of ​​the sealed container based on an inner diameter of the sealed container is S, whereby the ratio (A+B) / S of the total cross-sectional area (A+B) of all the passages to the cross-sectional area S of the sealed container is 0.05 or more ((A+B) / S≧0.05).

[0013] According to any of the above configurations, the cross-sectional area or heat transfer area of ​​the rotor passage provided in the rotor among the plurality of passages provided in the electric motor section is made relatively large, or a lower limit of the total cross-sectional area or total heat transfer area of ​​the plurality of passages is specified based on the cross-sectional area of ​​the sealed container. This makes it possible to give predominance to the rotor passage, which is relatively difficult to propagate the disproportionation reaction among all the passages provided in the electric motor section, and as a result, it is possible to effectively suppress propagation of the disproportionation reaction occurring in the space above or below the electric motor section to the space on the opposite side.

[0014] Furthermore, by suppressing the propagation of the disproportionation reaction, the cooling effect of the motor section, which is the main function of the multiple passages, can calm down and ultimately eliminate the disproportionation reaction itself. As a result, the possibility of a large-scale disproportionation reaction occurring throughout the entire compressor can be effectively suppressed or avoided, further improving the reliability of the compressor and also improving the reliability of the refrigeration cycle system including this compressor.

[0015] The present disclosure also includes a refrigeration cycle system that uses a working fluid for a refrigeration cycle containing at least a hydrofluoroolefin as a refrigerant component and is equipped with a compressor having any of the above configurations.

[0016] The above and other objects, features, and advantages of the present disclosure will become apparent from the following detailed description of preferred embodiments, which proceeds with reference to the accompanying drawings.

[0017] With the above-described configuration, the present invention has the effect of effectively suppressing or mitigating the propagation of the disproportionation reaction of hydrofluoroolefin without being significantly affected by the configuration of the compressor.

[0018] Fig. 3A is a schematic vertical cross-sectional view showing an example of a compressor according to an embodiment of the present disclosure. Fig. 3B is a schematic horizontal cross-sectional view showing an example of a passage of an electric motor section in the compressor shown in Fig. 1. Fig. 3A and Fig. 3B are schematic block diagrams showing an example of a refrigeration cycle system including the compressor shown in Fig. 1.

[0019] [Knowledge and other information forming the basis of the present disclosure] The compressor described in Patent Document 1 is based on the premise that the internal volume of the compressor, i.e., the volume of the sealed container (compressor shell), does not change substantially. Therefore, there are cases where a sufficient volume for installing a heat absorption unit within the sealed container cannot be secured. In such cases, the heat absorption unit will not be able to maintain a sufficient heat capacity to absorb the heat of the disproportionation reaction, and as a result, there is a possibility that the propagation of the disproportionation reaction will not be effectively suppressed.

[0020] Therefore, in order to secure the volume for installing the heat absorption part, it becomes necessary to increase the internal volume of the sealed container. In this case, it is not enough to simply increase the internal volume; the pressure-resistant design of the sealed container must also be reviewed. Furthermore, increasing the internal volume of the sealed container makes the compressor itself excessively large, which promotes the chain reaction of disproportionation reactions.

[0021] Furthermore, in the compressor described in Patent Document 1, as described above, the heat absorption parts include metal members arranged around the moving parts of the compressor, metal members arranged around the inside of the terminal pin, and metal members that constitute the compressor itself. In other words, these heat absorption parts are members installed in areas where high temperature and pressure are expected (moving parts of the compressor), members installed in areas that may trigger a disproportionation reaction (inside the terminal pin), or existing members that the compressor is equipped with.

[0022] In other words, these endothermic parts are not installed with consideration given to how the disproportionation reaction of hydrofluoroolefins generated in the compressor propagates within the compressor. Therefore, the heat generated when the disproportionation reaction occurs inside the compressor does not necessarily propagate selectively around the endothermic parts. As a result, these endothermic parts may not be able to effectively absorb the heat of the disproportionation reaction.

[0023] Therefore, as a result of extensive research, the inventors have independently found that the interior of a compressor can be divided into an upper space and a lower space when viewed from the motor section, that the disproportionation reaction of hydrofluoroolefin occurs in either the upper space or the lower space and then propagates to the other space via a plurality of passages provided in the motor section that communicate these spaces, and that, of the passages provided in the motor section, the passages provided in the rotor are more difficult for the disproportionation reaction to propagate than passages provided outside the rotor, and have completed the present invention based on these findings.

[0024] That is, the compressor according to the present disclosure is a compressor that uses a working fluid for a refrigeration cycle that contains at least a hydrofluoroolefin as a refrigerant component, and includes an electric motor unit having a rotor and a stator, a compression mechanism unit driven by the electric motor unit, and a sealed container that houses the electric motor unit and the compression mechanism unit, wherein spaces are provided above and below the electric motor unit within the sealed container, and the electric motor unit is provided with a plurality of passages that communicate with the upper space and the lower space, and wherein, when the total cross-sectional area of ​​all the passages provided in the rotor is A and the total cross-sectional area of ​​all the passages provided other than the rotor is B, the relationship A≧B is satisfied.

[0025] Alternatively, the compressor according to the present disclosure may be a compressor that uses a working fluid for a refrigeration cycle containing at least a hydrofluoroolefin as a refrigerant component, and includes an electric motor unit having a rotor and a stator, a compression mechanism unit driven by the electric motor unit, and a sealed container that houses the electric motor unit and the compression mechanism unit, wherein spaces are provided above and below the electric motor unit within the sealed container, and the electric motor unit is provided with a plurality of passages that communicate with the upper space and the lower space, and where the heat transfer area of ​​the passage is the product of the equivalent diameter d of the passage, the passage length L, and pi (π × d × L), where C is the total heat transfer area of ​​all the passages provided in the rotor and D is the total heat transfer area of ​​all the passages provided other than the rotor, and C is a configuration such that C≧D.

[0026] Alternatively, the compressor according to the present disclosure may be a compressor that uses a working fluid for a refrigeration cycle that contains at least a hydrofluoroolefin as a refrigerant component, and that includes: an electric motor unit having a rotor and a stator; a compression mechanism unit driven by the electric motor unit; and a sealed container that houses the electric motor unit and the compression mechanism unit; the sealed container has spaces above and below the electric motor unit; the electric motor unit has a plurality of passages that communicate with the upper space and the lower space; the heat transfer area of ​​the passages is defined as the product of the equivalent diameter d of the passage, the passage length L, and pi (π × d × L), the total heat transfer area of ​​all the passages provided in the rotor is defined as C; and the cross-sectional area of ​​the sealed container based on the inner diameter of the sealed container is defined as S, so that the ratio C / S of the total heat transfer area C to the cross-sectional area S is 1.0 or greater (C / S≧1.0).

[0027] Alternatively, the compressor according to the present disclosure may be a compressor that uses a working fluid for a refrigeration cycle that contains at least a hydrofluoroolefin as a refrigerant component, and that includes: an electric motor unit having a rotor and a stator; a compression mechanism unit driven by the electric motor unit; and a sealed container that houses the electric motor unit and the compression mechanism unit; the sealed container has spaces above and below the electric motor unit; the electric motor unit has a plurality of passages that communicate the upper space with the lower space; and the total cross-sectional area of ​​all the passages that are provided in the rotor is A, the total cross-sectional area of ​​all the passages that are provided other than the rotor is B, and the cross-sectional area of ​​the sealed container based on the inner diameter of the sealed container is S, where A is the total cross-sectional area of ​​all the passages and S is the cross-sectional area of ​​the sealed container, and (A+B) / S is 0.05 or more ((A+B) / S≧0.05).

[0028] In any of the above configurations, the cross-sectional area or heat transfer area of ​​the rotor passage provided in the rotor among the multiple passages provided in the electric motor unit is relatively large, or the lower limit of the total cross-sectional area or total heat transfer area of ​​the multiple passages is specified based on the cross-sectional area of ​​the sealed container. This makes it possible to make the cooling effect of the rotor passage dominant among all the passages provided in the electric motor unit, and as a result, it is possible to effectively prevent the disproportionation reaction occurring in the space above or below the electric motor unit from spreading to the space on the opposite side.

[0029] Furthermore, by suppressing the propagation of the disproportionation reaction, the cooling effect of the motor section, which is the main function of the multiple passages, can calm down and ultimately eliminate the disproportionation reaction itself. As a result, the possibility of a large-scale disproportionation reaction occurring throughout the entire compressor can be effectively suppressed or avoided, further improving the reliability of the compressor and also improving the reliability of the refrigeration cycle system including this compressor.

[0030] In the compressor having the above configuration, the passage provided other than the rotor may be at least one of an air gap passage formed between the rotor and the stator and a stator passage provided between the stator and the sealed container.

[0031] In the compressor having the above configuration, the hydrofluoroolefin may be at least one of 1,1,2-trifluoroethylene (HFO1123) and 1,2-difluoroethylene (HFO1132).

[0032] In the compressor having the above configuration, the working fluid for a refrigeration cycle may further contain difluoromethane as a refrigerant component and may also contain at least one of saturated hydrocarbons, haloalkanes, and fluoroalkanes having 1 to 3 carbon atoms and a boiling point of 0°C or lower (excluding difluoromethane) as a disproportionation inhibitor.

[0033] The present disclosure also includes a refrigeration cycle system that uses a working fluid for a refrigeration cycle containing at least a hydrofluoroolefin as a refrigerant component and that is equipped with a compressor having any of the above configurations.

[0034] Representative embodiments of the present invention will be described below with reference to the drawings. Note that the same or corresponding components will be designated by the same reference numerals throughout the drawings, and redundant description will be omitted.

[0035] [Refrigerant Component] In the compressor according to the present disclosure, a working fluid for a refrigeration cycle containing at least a hydrofluoroolefin (HFO) in which a disproportionation reaction occurs is used as a refrigerant component.

[0036] Specific examples of hydrofluoroolefins include, but are not limited to, those having two carbon atoms, such as 1,1,2-trifluoroethylene (CF2=CHF, HFO1123), trans-1,2-difluoroethylene (CHF=CHF(E), HFO1132(E)), and cis-1,2-difluoroethylene (CHF=CHF(Z), HFO1132(Z)). These hydrofluoroolefins may be used alone or in combination as a refrigerant component.

[0037] These hydrofluoroolefins have a backbone ethylene structure, i.e., a double bond between carbon atoms, and have a chemical structure in which at least one of the two hydrogen atoms bonded to one carbon atom is substituted with a fluorine atom, or at least one of the two hydrogen atoms bonded to both carbon atoms is substituted with a fluorine atom. Note that in hydrofluoroolefins, some of the hydrogen atoms may be substituted with other atoms or other substituents.

[0038] For example, 1,1,2-trifluoroethylene has a structure in which both of the two hydrogen atoms bonded to one carbon atom (the carbon atom at position 1) of the ethylene structure are substituted with fluorine atoms, and one of the two hydrogen atoms bonded to the other carbon atom (the carbon atom at position 2) is substituted with a fluorine atom.

[0039] Alternatively, trans-1,2-difluoroethylene has a structure in which one of the two hydrogen atoms bonded to the carbon atom at position 1 of the ethylene structure is substituted with a fluorine atom, and of the two hydrogen atoms bonded to the carbon atom at position 2, only the hydrogen atom at the position opposite to the carbon atom at position 1 across the double bond, rather than the hydrogen atom adjacent to the carbon atom at position 1, is substituted with a fluorine atom.

[0040] As described above, such hydrofluoroolefins contain an ethylene skeleton, i.e., a carbon-carbon double bond, and this double bond is easily decomposed. That is, atmospheric ozone generates hydroxyl radicals (OH radicals) through photochemical reactions, and these hydroxyl radicals can undergo addition reactions with double bonds, making the hydrofluoroolefins easily decomposed. For this reason, hydrofluoroolefins have little impact on ozone layer depletion and global warming.

[0041] The working fluid for a refrigeration cycle used in the present disclosure may contain difluoromethane (HFC32, R32, chemical formula: CHF) as a refrigerant component in addition to hydrofluoroolefin. In this case, if the hydrofluoroolefin is considered to be the "main component (main refrigerant component)" of the refrigerant component in the working fluid for a refrigeration cycle used in the present disclosure, the difluoromethane is considered to be the "secondary component (secondary refrigerant component)" of the refrigerant component in the working fluid for a refrigeration cycle used in the present disclosure.

[0042] As mentioned above, difluoromethane has an ozone depletion potential (ODP) of 0 and has good refrigerant performance compared to the HCFCs (hydrochlorofluorocarbons) that have been used up to now.

[0043] Furthermore, the working fluid for a refrigeration cycle used in the present disclosure may contain, as refrigerant components, "other refrigerant components" in addition to the hydrofluoroolefin as the main refrigerant component and difluoromethane as the secondary refrigerant component. Representative other refrigerant components include hydrofluorocarbons (HFCs) such as difluoroethane, trifluoroethane, tetrafluoroethane, pentafluoroethane, pentafluoropropane, hexafluoropropane, heptafluoropropane, pentafluorobutane, and heptafluorocyclopentane; and hydrofluoroolefins (HFOs) having 3 or more carbon atoms such as monofluoropropene, trifluoropropene, tetrafluoropropene, pentafluoropropene, and hexafluorobutene, but are not particularly limited thereto.

[0044] These other refrigerant components are known to have little impact on ozone layer depletion and global warming, and therefore can be used in combination with hydrofluoroolefins, or with hydrofluoroolefins and difluoromethane, as refrigerant components. The above-mentioned other refrigerant components may be used in combination alone or in appropriate combination of two or more.

[0045] The content of hydrofluoroolefin in the working fluid for a refrigeration cycle is not particularly limited, but when the total amount of the refrigerant components and the disproportionation inhibitor described below among the components constituting the working fluid for a refrigeration cycle (for convenience of explanation, referred to as the "total amount of refrigerant-related components") is taken as 100% by mass, the content of hydrofluoroolefin may be 40% by mass or more, and although the lower limit of the content of hydrofluoroolefin may be 40% by mass as described above, it is preferably 45% by mass or more, more preferably 50% by mass or more, and even more preferably 70% by mass or more.

[0046] If the content of the hydrofluoroolefin is less than 40% by mass of the total amount of the refrigerant-related components, the content of the hydrofluoroolefin in the working fluid for a refrigeration cycle will be too low, resulting in the inclusion of a large amount of other refrigerant components, and therefore the advantages of using a hydrofluoroolefin with a small GWP in a working fluid for a refrigeration cycle will not be fully obtained.

[0047] Furthermore, the upper limit of the hydrofluoroolefin content is not particularly limited, but may be 98.8 mass% or less of the total amount of refrigerant-related components. As will be described later, in the present disclosure, the working fluid for a refrigeration cycle may contain a disproportionation inhibitor that is gaseous or liquid at room temperature and normal pressure. A preferred lower limit of the content of this disproportionation inhibitor is 1.2 mass%. Therefore, if only hydrofluoroolefin is used as a refrigerant component and no other refrigerant components are used (the refrigerant components are 100 mass% hydrofluoroolefin), the upper limit of the hydrofluoroolefin content in the total amount of refrigerant-related components will necessarily be 98.8 mass%.

[0048] When a refrigerant component other than hydrofluoroolefin is contained as a refrigerant component, the content of the other refrigerant component is not particularly limited. For example, as mentioned above, a preferred example of the other refrigerant component is difluoromethane. However, since the preferred upper limit of the content of hydrofluoroolefin, which is an essential refrigerant component, is 40 mass% of the total amount of refrigerant-related components, the content of difluoromethane may be less than 60 mass% of the total amount of refrigerant-related components. Note that when other refrigerant components are contained, a particularly preferred content of hydrofluoroolefin is, but is not limited to, a range of 70 mass% to 80 mass%.

[0049] [Other Components That Can Be Used in Combination] The working fluid for a refrigeration cycle used in the present disclosure is used in a refrigeration cycle system, and therefore can be used in combination with a lubricating oil (refrigerating machine oil) that lubricates the hermetic compressor provided in the refrigeration cycle system. As described above, the working fluid for a refrigeration cycle used in the present disclosure only needs to be composed of at least a refrigerant component whose "main component" is a hydrofluoroolefin. Furthermore, when the working fluid for a refrigeration cycle is used in combination with a lubricating oil, the working fluid-containing composition can be considered to be composed of the refrigerant component, the lubricating oil component, and other components.

[0050] The lubricating oil component contained in the working fluid-containing composition (used in combination with the working fluid for a refrigeration cycle) can be any of various lubricating oils known in refrigeration cycle systems. Specific examples of lubricating oils include, but are not limited to, ester-based lubricating oils, ether-based lubricating oils, glycol-based lubricating oils, alkylbenzene-based lubricating oils, fluorine-based lubricating oils, mineral oils, and hydrocarbon-based synthetic oils. These lubricating oils may be used alone or in combination of two or more.

[0051] Various known additives may also be added to the working fluid-containing composition. Specific additives include, but are not limited to, antioxidants, moisture scavengers, metal deactivators, anti-wear agents, and anti-foaming agents. Antioxidants are used to improve the thermal stability, oxidation resistance, chemical stability, etc. of refrigerant components or lubricating oils. Moisture scavengers are used to remove moisture when it infiltrates into a refrigeration cycle system, and are particularly used to suppress changes in the properties of lubricating oils. Metal deactivators are used to suppress or prevent chemical reactions caused by the catalytic action of metal components. Anti-wear agents are used to reduce wear on sliding parts in compressors, especially during high-pressure operation. Anti-foaming agents are used, particularly, to suppress the generation of bubbles in lubricating oils.

[0052] The specific types of these additives are not particularly limited, and known compounds can be suitably used depending on various conditions. Furthermore, as these additives, only one type of compound or an appropriate combination of two or more types of compounds can be used. Furthermore, the amount of these additives added is not particularly limited, and they can be added within known ranges as long as the properties of the working fluid for a refrigeration cycle used in the present disclosure or the working fluid-containing composition containing the same are not impaired.

[0053] As described above, a disproportionation inhibitor that is gaseous or liquid at room temperature and normal pressure may be added in advance to the working fluid for a refrigeration cycle used in the present disclosure. Specific examples of the disproportionation inhibitor include saturated hydrocarbons having 2 to 5 carbon atoms, haloalkanes having 1 or 2 carbon atoms except for those in which all halogen atoms are fluorine, and fluoroalkanes having 1 to 3 carbon atoms (excluding difluoromethane) with a boiling point of 0°C or lower. These disproportionation inhibitors may be used alone or in appropriate combination of two or more.

[0054] Specific examples of the disproportionation inhibitor include, but are not limited to, saturated hydrocarbons such as ethane, n-propane, cyclopropane, n-butane, cyclobutane, isobutane (2-methylpropane), methylcyclopropane, n-pentane, isopentane (2-methylbutane), neopentane (2,2-dimethylpropane), and methylcyclobutane. Of these, n-propane is particularly preferred.

[0055] Examples of haloalkanes having one carbon atom, i.e., halomethanes, include, but are not limited to, (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 (CHFI2), difluorodiiodomethane (CF2I2), dibromodifluoromethane (CBr2F2), trifluoroiodomethane (CF3I), and difluoroiodomethane (CHF2I). Among these, dibromomethane (CH2Br2), bromomethane (CH3Br), dibromodichloromethane (CBr2Cl2), trifluoroiodomethane (CF3I), etc. are preferred, and trifluoroiodomethane (CF3I) is more preferred.

[0056] Furthermore, examples of haloalkanes having two carbon atoms, i.e., haloethanes, include 1,1,1-trifluoro-2-iodoethane (CF3CH2I), monoiodoethane (CH3CH2I), monobromoethane (CH3CH2Br), 1,1,1-triiodoethane (CH3CI3), etc. Among these, 1,1,1-trifluoro-2-iodoethane (CF3CH2I) is particularly preferably used, taking into consideration availability, ODP value, handleability, etc.

[0057] Examples of the fluoroalkanes having 1 to 3 carbon atoms include fluoromethane (boiling point -78.2°C), difluoromethane (boiling point -51.6°C), trifluoromethane (boiling point -84.4°C), and tetrafluoromethane (boiling point -127.8°C); fluoroethane (boiling point -37.1°C), 1,1-difluoroethane (boiling point -24.7°C), 1,1,1-trifluoroethane (boiling point -47.2°C), 1,1,1,2-tetrafluoroethane (boiling point -26.3°C), and 1, Examples of suitable fluoroethanes include 1,1,2,2-pentafluoroethane (boiling point: -48.5°C); and fluoropropanes such as 1-fluoropropane (boiling point: -2.5°C), 2-fluoropropane (boiling point: -10.0°C), 2,2-difluoropropane (boiling point: -1.0°C), 1,1,1-trifluoropropane (boiling point: -12.0°C), 1,1,2,2-tetrafluoropropane (boiling point: -0.8°C), and 1,1,1,3,3,3-hexafluoropropane (boiling point: -1.4°C).

[0058] The amount of disproportionation inhibitor added is not particularly limited, but when the total amount of refrigerant-related components (total amount of refrigerant components and disproportionation inhibitor) is taken as 100% by mass, the upper limit of the amount (content) of disproportionation inhibitor added may be 10% by mass or less of the total amount of refrigerant-related components, preferably 5% by mass or less, and more preferably 3% by mass or less. This is because if the content of disproportionation inhibitor exceeds 10% by mass of the total amount of refrigerant-related components, the content of disproportionation inhibitor will be too high when viewed as a working fluid for a refrigeration cycle, and there is a possibility that the working fluid will not be able to exhibit good physical properties as a "refrigerant." Of course, depending on the composition of the working fluid for a refrigeration cycle, the disproportionation inhibitor may be added in an amount of 10% by mass or more of the total amount of refrigerant-related components.

[0059] As the disproportionation inhibitor, as described above, two or more of saturated hydrocarbons, haloalkanes, and fluoroalkanes can be used in combination. In this case, the mixing ratio of saturated hydrocarbons, haloalkanes, and fluoroalkanes is not particularly limited. As described above, a preferred content of the total amount of disproportionation inhibitors is 10 mass% or less, so it is sufficient that two or more of saturated hydrocarbons, haloalkanes, and fluoroalkanes are used in combination at an appropriate mixing ratio within this range.

[0060] In the present disclosure, a plurality of types of saturated hydrocarbons, haloalkanes, and fluoroalkanes may be used in combination. Therefore, the combination of two or more types of saturated hydrocarbons, haloalkanes, and fluoroalkanes as used herein means that two or more types of compounds classified as saturated hydrocarbons, one or more types of compounds classified as haloalkanes, and one or more types of compounds classified as fluoroalkanes may be used in combination.

[0061] Here, saturated hydrocarbons, haloalkanes, and fluoroalkanes can suppress or moderate the progress of disproportionation reactions even when added in amounts of 10% by mass or less, respectively. Furthermore, as disclosed herein, when two or more saturated hydrocarbons, haloalkanes, and fluoroalkanes are used in combination, it is possible to suppress or moderate the progress of disproportionation reactions with even smaller amounts than when each is added alone. More specifically, the upper limit of the amount of disproportionation inhibitor added based on the total amount (total amount of two or more of saturated hydrocarbons, haloalkanes, and fluoroalkanes) may be 10% by mass or less, and may even be 5% by mass or less. However, when saturated hydrocarbons and haloalkanes are combined, a more preferred upper limit is 3% by mass or less.

[0062] At this time, the mixing ratio of two or more of saturated hydrocarbons, haloalkanes, and fluoroalkanes is not particularly limited. For example, when saturated hydrocarbons and haloalkanes are used in combination, when the added amount is 3 mass% or less, a typical example of the mixing ratio of saturated hydrocarbons to haloalkanes can be in the range of 1:0.5 to 1:2 by mass. Here, there are three combinations of saturated hydrocarbons and haloalkanes, and representative mixing ratios for each combination are as follows: [1] A combination of three types of saturated hydrocarbons, haloethane, and halomethane can be in the range of 1:0.25:0.25 to 1:1:1 by mass; [2] A combination of two types of saturated hydrocarbons and haloethane can be in the range of 1:0.25 to 1:1; and [3] A combination of two types of saturated hydrocarbons and halomethane can be in the range of 1:0.25 to 1:1.

[0063] Furthermore, the lower limit of the amount of two or more of saturated hydrocarbons, haloalkanes, and fluoroalkanes added is not particularly limited, but a typical lower limit can be 1.2 mass% or more of the total amount of refrigerant-related components. Even if the total amount of two or more of saturated hydrocarbons, haloalkanes, and fluoroalkanes is less than 1.2 mass%, it is possible to obtain the effect of inhibiting disproportionation reactions, but if it is 1.2 mass% or more, the effect of inhibiting disproportionation reactions can be more suitably achieved. Therefore, in the present disclosure, a more preferred range for the content of two or more of saturated hydrocarbons, haloalkanes, and fluoroalkanes is 1.2 mass% or more and 3 mass% or less of the total amount of refrigerant-related components.

[0064] [Configuration example of compressor] Next, a typical example of a compressor according to the present disclosure will be described. The compressor according to the present disclosure is not particularly limited in specific configuration as long as it uses the above-mentioned working fluid for a refrigeration cycle, i.e., a working fluid for a refrigeration cycle containing a hydrofluoroolefin that undergoes a disproportionation reaction as a refrigerant component. A typical example is a rotary compressor 30 shown in FIG. 1. This rotary compressor 30 is a typical example of a compressor used in a home air conditioner described below. This air conditioner is an example of a refrigeration cycle system (or refrigeration cycle device) according to the present disclosure.

[0065] The compressor 30 includes an electric motor unit 41 and a compression mechanism unit 42 housed in a sealed container 31 (or compressor shell). The sealed container 31 is a vertically long cylinder, and in the configuration shown in Fig. 1, for example, it is composed of an upper shell 32, a body shell 33, and a lower shell 34. The upper shell 32 forms the upper part of the sealed container 31, the lower shell 34 forms the lower part of the sealed container 31, and the body shell 33 forms the majority of the sealed container 31 (the main body of the sealed container 31). The upper shell 32 and the lower shell 34 are fitted into the body shell 33. A discharge pipe 35 is provided in the upper shell 32, and a suction pipe 36 is provided on the lower side of the body shell 33.

[0066] The electric motor unit 41 is a motor including a rotor 43 and a stator 44, and the rotor 43 is provided with a shaft 45. The shaft 45 is rotatably connected to a piston 46 included in the compression mechanism unit 42, and the piston 46 rotates within a cylinder 47 included in the compression mechanism unit 42. Therefore, the compression mechanism unit 42 is driven by the electric motor unit 41.

[0067] 1, the electric motor unit 41 is located at the upper side within the sealed container 31, and the compression mechanism unit 42 is located below the electric motor unit 41. Therefore, the electric motor unit 41 is located at the upper part of the internal space of the sealed container 31, and the compression mechanism unit 42 is located at the lower part of the internal space. Lubricating oil 48 is also sealed within the sealed container 31. In the example shown in FIG. 1, the lubricating oil 48 is stored below the compression mechanism unit 42 within the sealed container 31 (at the bottom of the sealed container 31).

[0068] The electric motor unit 41 and the cylinder 47 of the compression mechanism unit 42 have an outer diameter approximately the same as the inner diameter of the cylindrical sealed container 31. Rotation of the electric motor unit 41 rotates the shaft 45, and this rotational driving force is transmitted to a piston 46 of the compression mechanism unit 42. The piston 46 rotates within the cylinder 47 by the rotational driving force of the electric motor unit 41. Low-pressure gas refrigerant is introduced into the cylinder 47 from the suction pipe 36, compressed by the rotation of the cylinder 47, and discharged as high-pressure refrigerant gas into the sealed container 31 (below the electric motor unit 41). The refrigerant then flows to the upper part of the electric motor unit 41 through a passage provided in the electric motor unit 41, and is discharged to the outside of the compressor 30 from the discharge pipe 35 at the upper end of the sealed container 31.

[0069] Here, within the sealed container 31 of the compressor 30, spaces 31a and 31b are provided above and below the electric motor unit 41. In the example shown in Fig. 1 , within the sealed container 31, the internal space extending from the top of the electric motor unit 41 to the upper shell 32 is the upper space 31a, and the internal space between the bottom of the electric motor unit 41 and the top of the compression mechanism unit 42 is the lower space 31b. In the compressor 30 according to the present disclosure, as shown in Fig. 2 in addition to Fig. 1 , a plurality of passages 43a, 44a, and 44b that connect the upper space 31a and the lower space 31b are provided in the electric motor unit 41.

[0070] These multiple passages 43a, 44a, 44b can be divided into a passage 43a provided in the rotor 43 of the electric motor section 41 and passages 44a, 44b provided outside the rotor 43. For ease of explanation, the former will be referred to as the rotor passage 43a, and the latter will be referred to as the extra-rotor passages 44a, 44b.

[0071] Note that while FIG. 1 is a schematic longitudinal cross-sectional view of the compressor 30, FIG. 2 is a schematic transverse cross-sectional view of the compressor 30, corresponding to a transverse cross-section of the portion of the electric motor unit 41 where the rotor 43 and the stator 44 are located. In this disclosure, a cross-section along the vertical direction of the compressor 30 is referred to as a longitudinal cross-section, and a cross-section along a direction perpendicular to the vertical direction is referred to as a transverse cross-section. The "cross-sectional area of ​​a passage" or "cross-sectional area of ​​the sealed container (compressor 30)" described below refers to the area of ​​the transverse cross-section. Also, in FIG. 2, the rotor 43 and the stator 44 are schematically hatched to clearly illustrate the passages 43a, 44a, and 44b. However, the rotor 43 and the stator 44 do not necessarily have the simple structure shown in FIG. 2.

[0072] As shown by dotted lines in Fig. 1 , the rotor passages 43a are provided so as to penetrate the rotor 43 along the axial direction of the rotor 43. In the example shown in Fig. 2 , six rotor passages 43a are provided at equal intervals between the outer peripheral surface and the inner peripheral surface of the rotor 43 so as to have the same radius as seen from the rotation axis, and each has an elliptical cross section. However, the specific configuration of the rotor passages 43a is not limited thereto. As long as the rotor passages 43a are formed inside the rotor 43 so as to communicate the upper space 31a and the lower space 31b, the number of rotor passages 43a is not particularly limited, as long as the rotor passages 43a do not interfere with the appropriate rotation performance of the rotor 43.

[0073] Of the rotor outer passages 44a and 44b, the stator passage 44a is formed between the sealed container 31 (the body shell 33 in FIG. 2 ) and the stator 44 so as to be recessed toward the inside of the stator 44 (toward the shaft 45). Note that in FIG. 1 , the stator passage 44a, like the rotor passage 43a, is illustrated by a dotted line. In the example shown in FIG. 2 , ten stator passages 44a are provided at equal intervals on the outer surface of the stator 44, and each has a semicircular cross section. However, the specific configuration of the stator passage 44a is not limited thereto. As long as the function of the stator 44 is not hindered, the number of stator passages 44a need only be formed on the outer surface of the stator 44 so as to communicate the upper space 31a and the lower space 31b, and there is no particular limitation on the number of stator passages 44a.

[0074] Of the rotor outer passages 44a and 44b, the air gap passage 44b utilizes, as the rotor outer passage, an air gap that is a gap formed between the rotor 43 and the stator 44. Generally, an air gap that is a cylindrical space is formed between the rotor 43 and the stator 44. Therefore, in the present disclosure, the air gap passage 44b can utilize the air gap that is normally provided in the electric motor section 41 as it is.

[0075] Here, the air gap is set as narrow as possible within a range that does not mechanically contact the rotor 43 and the stator 44. This is because narrowing (reducing) the air gap makes it possible to strengthen the magnetic field and improve the power density of the rotor 43. Conversely, from the perspective of using the air gap as a rotor outer passage, the air gap may be widened within a range that allows the required power density of the rotor 43 to be achieved.

[0076] In this embodiment, the stator passage 44a and the air gap passage 44b are cited as examples of rotor extra-passages, but specific configuration examples of the rotor extra-passages are not limited to these, and a passage other than the stator passage 44a or the air gap passage 44b may be provided in a location other than the rotor 43. Furthermore, for example, if the air gap passage 44b alone can provide good communication between the upper space 31a and the lower space 31b, the stator passage 44a does not need to be provided. Alternatively, if the stator passage 44a alone can provide good communication between the upper space 31a and the lower space 31b, the air gap may be made as narrow as possible to the extent that it does not function sufficiently as a passage.

[0077] In the compressor 30 according to the present disclosure, in the above-described configuration, predetermined conditions are set for the cross-sectional area and / or heat transfer area between at least two or more components among the group of components consisting of the rotor passage 43 a and the rotor outer passage of the electric motor section 41, and the sealed container 31.

[0078] Specifically, the following conditions can be mentioned: [Condition 1] When the total cross-sectional area of ​​the rotor passage 43a is A and the total cross-sectional area of ​​the rotor extra-passages is B, A ≥ B; [Condition 2] When the total heat transfer area of ​​the rotor passage 43a is C and the total heat transfer area of ​​the rotor extra-passages is D, C ≥ D; [Condition 3] When the cross-sectional area of ​​the sealed container 31 based on the inner diameter of the sealed container 31 (container cross-sectional area) is S, the ratio C / S of the total heat transfer area C of the rotor passage 43a to the container cross-sectional area S is 1.0 or more (C / S ≥ 1.0); and [Condition 4] When the total cross-sectional area A+B of all the passages 43a, 44a, 44b (i.e., the sum of the total cross-sectional area A of the rotor passage 43a and the total cross-sectional area B of the rotor extra-passages) to the container cross-sectional area S is 0.05 or more ((A+B) / S ≥ 0.05).

[0079] Among the above conditions 1 to 4, the heat transfer areas of the passages 43a, 44a, and 44b under conditions 2 and 3 are calculated as the product of the equivalent diameter d of each passage, the passage length L, and pi (π × d × L).

[0080] As a result, within the internal space of the sealed container 31, the area above the electric motor unit 41 is the upper space 31a as described above, and the area below the electric motor unit 41 is the lower space 31b, so that, for example, when a disproportionation reaction of a hydrofluoroolefin occurs in the upper space 31a, the disproportionation reaction can be effectively prevented from spreading to the other lower space 31b. Note that even when a disproportionation reaction occurs in the lower space 31b, the disproportionation reaction can be effectively prevented from spreading to the other upper space 31a.

[0081] The electric motor section 41 of the compressor 30 generates heat during operation, which can lead to a decrease in performance or the occurrence of abnormalities. Therefore, a passage is generally provided in the electric motor section 41, and a working medium for a refrigeration cycle is passed through this passage to cool the electric motor section 41. For the purpose of cooling the electric motor section 41, the passage may be provided in the rotor 43 or the stator 44.

[0082] 1, the electric motor unit 41 is positioned so as to be "filled" in the cross-sectional direction within the sealed container 31 without any gaps. In this configuration, the working fluid for the refrigeration cycle discharged from the compression mechanism unit 42 below is a "compressed mixed gas" in which the refrigerant components and the lubricating oil 48 are mixed, i.e., the working fluid-containing composition described above.

[0083] Therefore, a passage is provided in the motor section 41, and the compressed gas mixture is circulated through the passage, thereby cooling the motor section 41 and separating the lubricating oil 48 from the compressed gas mixture. As a result, a working fluid for a refrigeration cycle, which is substantially mainly composed of a refrigerant component, is discharged from the discharge pipe 35 located at the top of the sealed container 31.

[0084] In other words, the passages provided in the electric motor section 41 have the function of cooling the electric motor section 41 with the working fluid for the refrigeration cycle or the working fluid-containing composition, and the function of separating the lubricating oil 48 from the working fluid-containing composition in order to discharge substantially the working fluid for the refrigeration cycle (almost only the refrigerant component) from the discharge pipe 35. In order to achieve these functions, the positions of the passages in the electric motor section 41 are not particularly limited, and any number of passages may be provided at any positions in the electric motor section 41, taking into consideration the various conditions required for the compressor 30.

[0085] Here, the present inventors have conducted extensive research into the propagation of the disproportionation reaction within the compressor 30 and have found that the disproportionation reaction of hydrofluoroolefins occurs in either the upper space 31a or the lower space 31b. The disproportionation reaction is induced by discharges at the coil ends or the like that occur during use of the working fluid for the refrigeration cycle, but it is extremely rare for this to occur simultaneously above or below the motor section 41, and the disproportionation reaction occurs either above or below. It is believed that the disproportionation reaction then propagates to the other space via multiple passages that communicate between these spaces 31a and 31b. Furthermore, it is believed that, of these multiple passages, the disproportionation reaction is less likely to propagate through the rotor passage 43a provided in the rotor 43 than through the outer-rotor passages.

[0086] In general, there is a correlation between the high-temperature, high-pressure state inside the compressor 30 (inside the sealed container 31) and the rotation speed of the rotor 43. When the rotor 43 is rotating at high pressure, the inside of the compressor 30 is normally at high temperature and high pressure. In a situation where a disproportionation reaction occurs in hydrofluoroolefin, the inside of the compressor 30 is basically in a high-temperature, high-pressure state, but the rotor 43 at this time is in a state of rotating at almost high speed. Conversely, when the rotor 43 is rotating at low speed, the disproportionation reaction hardly occurs. Therefore, at low speed, it is thought that the inside of the compressor 30 does not reach a high temperature and high pressure sufficient to cause the disproportionation reaction.

[0087] The passages 43a, 44a, and 44b provided in the electric motor section 41 are considered to have substantially the same function in terms of cooling the electric motor section 41 and separating the lubricating oil 48. However, from the viewpoint of propagation of the disproportionation reaction, it is considered that the rotor passage 43a is less likely to propagate the disproportionation reaction than the outer-rotor passages such as the passages 44a and 44b.

[0088] The reason for this is believed to be as follows: Refrigerant compressed by the compression mechanism 42 is discharged into the sealed container 31, cooling the motor 41 and separating the lubricating oil 48. At this time, part of the refrigerant near the rotor 43, which is rotating at high speed, is guided into the rotor passage 43a, and part is guided out of the sealed container 31 by centrifugal force, so that a refrigerant flow is always formed from near the rotor 43 to the stator 44 of the motor 41. Here, in order for a disproportionation reaction occurring at a location above or below the stator 44 of the motor 41 to propagate into the rotor passage 43a, which is rotating at high speed, it must propagate against the flow direction of the refrigerant flow. Therefore, the rotor passage 43a is characterized by being difficult to propagate the disproportionation reaction.

[0089] Therefore, for example, as per the above-mentioned condition 1, the passages 43a, 44a, 44b provided in the motor section 41 are divided into a passage 43a provided in the rotor 43 (rotor passage 43a) and passages 44a, 44b provided outside the rotor 43 (external rotor passages), and the total cross-sectional area A of the rotor passage 43a is set to be larger than the total cross-sectional area B of the external rotor passages.

[0090] This allows the electric motor section 41 to be efficiently cooled, and allows the lubricating oil 48 to be efficiently separated from the compressed mixed gas (working-fluid-containing composition) discharged from the compression mechanism section 42. Moreover, even if a disproportionation reaction occurs in the upper space 31a, for example, the total cross-sectional area A of the rotor passage 43a is larger than the total cross-sectional area B of the outer-rotor passages, so the disproportionation reaction is less likely to propagate to the lower space 31b via the rotor passage 43a, and ultimately, the disproportionation reaction itself can be calmed down and eliminated as the electric motor section 41 is cooled.

[0091] In other words, the disproportionation reaction is confined in the upper space 31 a by the rotor 43 having the rotor passage 43 a with a larger total cross-sectional area, and can be extinguished before it propagates to the opposite lower space 31 b. In particular, since the disproportionation reaction occurs at the same time as the rotor 43 rotates at high speed under high temperature and pressure, propagation can be more effectively suppressed.

[0092] The condition 2 is a condition that the total heat transfer area C of the rotor passage 43a is larger than the total heat transfer area D of the outer-rotor passages. Therefore, similar to the condition 1, the motor section 41 can be efficiently cooled, the lubricating oil 48 can be efficiently separated from the compressed gas mixture, and the disproportionation reaction occurring in the upper space 31a or the lower space 31b can be calmed and eliminated before it propagates to the opposite side.

[0093] The condition 3 is that the ratio C / S of the total heat transfer area C of the rotor passages 43a to the vessel cross-sectional area S (transverse cross-sectional area of ​​the sealed vessel 31) is 1.0 or more. This condition 3 means that the total heat transfer area C of the rotor passages 43a is set larger than the vessel cross-sectional area S.

[0094] That is, under the above-mentioned condition 1 or condition 2, the cross-sectional area or heat transfer area is set for two components, the rotor passage 43a and the rotor outer passage, among the component group consisting of the rotor passage 43a, the rotor outer passage, and the sealed container 31. On the other hand, under condition 3, the heat transfer area and the cross-sectional area ratio are set for the rotor passage 43a and the sealed container 31.

[0095] Here, under Condition 3, the total heat transfer area C of the rotor passage 43a is set large based on the vessel cross-sectional area S. Consequently, as a result, the heat transfer area of ​​the rotor passage 43a is set large, similar to Condition 2. Therefore, under Condition 3, as with Condition 2, it is possible to cool the motor section 41, separate the lubricating oil 48 from the compressed gas mixture, and suppress and calm the propagation of the disproportionation reaction.

[0096] Condition 4 above is a condition that the ratio (A+B) / S of the total cross-sectional area A+B of all passages 43a, 44a, 44b to the vessel cross-sectional area S is 0.05 or greater. Condition 4 sets the cross-sectional areas for all of the components consisting of rotor passage 43a, rotor outer passages, and sealed vessel 31. In other words, condition 4 differs from conditions 1 to 3 above and can be said to be a condition that defines the lower limit of the total cross-sectional area of ​​all passages provided in motor section 41, using vessel cross-sectional area S as a reference.

[0097] According to Condition 4, the cross-sectional areas of the rotor passage 43a and the outer-rotor passages in the electric motor section 41 are all set relatively large, which makes it possible to effectively cool the electric motor section 41 and separate the lubricating oil 48 from the compressed gas mixture, similar to Conditions 1 to 3.

[0098] Here, unlike Conditions 1 to 3, Condition 4 does not prioritize rotor passage 43a, but provides passages 43a, 44a, and 44b with a cross-sectional area sufficient for the electric motor section 41. This ensures that the total cross-sectional area A of rotor passage 43a is large enough to make it difficult for the disproportionation reaction to propagate to the lower space 31b via rotor passage 43a. As a result, the propagation of the disproportionation reaction can be suppressed and calmed down.

[0099] The compressor 30 according to the present disclosure may satisfy any one of the above-described conditions 1 to 4, but may also satisfy two or more, three or more, or all four of these four conditions. This effectively suppresses or avoids the possibility of a large-scale disproportionation reaction occurring throughout the entire interior of the compressor 30, thereby further improving the reliability of the compressor 30.

[0100] Furthermore, in the compressor 30 according to the present disclosure, the working fluid for a refrigeration cycle used may contain a hydrofluoroolefin as a refrigerant component, but may also contain the disproportionation inhibitor described above. This not only enables the compressor 30 to suppress the propagation of the disproportionation reaction by satisfying any one of conditions 1 to 4, but also enables the disproportionation inhibitor to effectively suppress or mitigate the disproportionation reaction of the hydrofluoroolefin. This makes it more difficult for the disproportionation reaction to occur inside the compressor 30, thereby further improving the reliability of the compressor 30.

[0101] Furthermore, the working fluid for a refrigeration cycle used in the compressor 30 according to the present disclosure may contain, as a refrigerant component, the aforementioned hydrofluorocarbon or another hydrofluoroolefin in addition to the hydrofluoroolefin. Typically, the working fluid for a refrigeration cycle may contain 1,1,2-trifluoroethylene as the hydrofluoroolefin and difluoromethane as another refrigerant component. Use of such a working fluid for a refrigeration cycle can make the refrigeration cycle more efficient while reducing the impact on the environment in a refrigeration cycle system including the compressor 30.

[0102] [Configuration example of refrigeration cycle system] Next, an example of a refrigeration cycle system (refrigeration cycle device) according to the present disclosure, i.e., a refrigeration cycle system including the compressor according to the present disclosure as described above, will be described with reference to Figures 3A and 3B. The compressor according to the present disclosure uses the above-mentioned working fluid for the refrigeration cycle (a working fluid containing a hydrofluoroolefin in which a disproportionation reaction occurs as a refrigerant component), and therefore the refrigeration cycle system according to the present disclosure is also configured using the above-mentioned working fluid for the refrigeration cycle.

[0103] The specific configuration of the refrigeration cycle system according to the present disclosure is not particularly limited as long as components such as a compressor, a condenser, an expansion means, and an evaporator are connected by piping. Specific application examples of the refrigeration cycle system according to the present disclosure are also not particularly limited, and examples include air conditioners, refrigerators (for home and commercial use), dehumidifiers, showcases, ice makers, heat pump water heaters, heat pump washer-dryers, and vending machines.

[0104] An air conditioner will be described as a typical application example of the refrigeration cycle system according to the present disclosure. Specifically, as shown in the block diagram of Fig. 3A, the air conditioner 10 according to this embodiment includes an indoor unit 11, an outdoor unit 12, and piping 13 connecting these. The indoor unit 11 includes a heat exchanger 14, and the outdoor unit 12 includes a heat exchanger 15, a compressor 30, and a pressure reducing device 16.

[0105] The heat exchanger 14 of the indoor unit 11 and the heat exchanger 15 of the outdoor unit 12 are connected in a ring shape by piping 13, thereby forming a refrigeration cycle. Specifically, the heat exchanger 14 of the indoor unit 11, the compressor 30, the heat exchanger 15 of the outdoor unit 12, and the pressure reducing device 16 are connected in this order by piping 13 in a ring shape. The piping 13 connecting the heat exchanger 14, the compressor 30, and the heat exchanger 15 is provided with a four-way valve 17 for switching between heating and cooling. The indoor unit 11 is equipped with a blower fan, a temperature sensor, an operating unit, etc. (not shown), and the outdoor unit 12 is equipped with a blower, an accumulator, etc. (not shown). The piping 13 is also provided with various valve devices (including the four-way valve 17), a strainer, etc. (not shown).

[0106] The heat exchanger 14 provided in the indoor unit 11 exchanges heat between indoor air drawn into the indoor unit 11 by the blower fan and the refrigerant flowing inside the heat exchanger 14. During heating, the indoor unit 11 blows air heated by heat exchange into the room, and during cooling, it blows air cooled by heat exchange into the room. The heat exchanger 15 provided in the outdoor unit 12 exchanges heat between outside air drawn into the outdoor unit 12 by the blower and the refrigerant flowing inside the heat exchanger 15.

[0107] The specific configurations of the indoor unit 11 and the outdoor unit 12, or the specific configurations of the heat exchanger 14 or heat exchanger 15, compressor 30, pressure reducing device 16, four-way valve 17, blower fan, temperature sensor, operating unit, blower, accumulator, other valve devices, strainer, etc. are not particularly limited, and known configurations can be suitably used.

[0108] An example of the operation of the air conditioner 10 shown in Figure 3A will be described in detail. First, during cooling operation or dehumidification operation, the compressor 30 of the outdoor unit 12 compresses and discharges gas refrigerant, which is then sent to the heat exchanger 15 of the outdoor unit 12 via the four-way valve 17. The heat exchanger 15 exchanges heat between the gas refrigerant and outside air, causing the gas refrigerant to condense and liquefy. The liquefied liquid refrigerant is depressurized by the pressure reducing device 16 and sent to the heat exchanger 14 of the indoor unit 11. In the heat exchanger 14, the liquid refrigerant evaporates into gas refrigerant through heat exchange with the indoor air. This gas refrigerant returns to the compressor 30 of the outdoor unit 12 via the four-way valve 17. The compressor 30 compresses the gas refrigerant and discharges it again to the heat exchanger 15 via the four-way valve 17.

[0109] Furthermore, during heating operation, the compressor 30 of the outdoor unit 12 compresses and discharges gas refrigerant, which is then sent to the heat exchanger 14 of the indoor unit 11 via the four-way valve 17. In the heat exchanger 14, the gas refrigerant condenses and liquefies through heat exchange with the indoor air. The liquefied liquid refrigerant is decompressed by the pressure reducing device 16 to become a two-phase gas-liquid refrigerant and is sent to the heat exchanger 15 of the outdoor unit 12. As the heat exchanger 15 exchanges heat between the outside air and the two-phase gas-liquid refrigerant, the two-phase gas-liquid refrigerant evaporates and becomes gas refrigerant, which returns to the compressor 30. The compressor 30 compresses the gas refrigerant and discharges it again via the four-way valve 17 to the heat exchanger 14 of the indoor unit 11.

[0110] A refrigerator will be described as another typical application example of the refrigeration cycle system according to the present disclosure. Specifically, as shown in the block diagram of Fig. 3B, refrigerator 20 according to this embodiment includes compressor 30, condenser 21, pressure reducing device 22, evaporator 23, and piping 24, which are shown in Fig. 1. Refrigerator 20 also includes a housing, a blower, an operation unit, a control unit, and the like, which are not shown.

[0111] The compressor 30 compresses the refrigerant gas to form a high-temperature, high-pressure gas refrigerant. The condenser 21 cools the refrigerant to liquefy it. The pressure reducing device 22, which is formed, for example, by a capillary tube, reduces the pressure of the liquefied refrigerant (liquid refrigerant). The evaporator 23 evaporates the refrigerant to form a low-temperature, low-pressure gas refrigerant. The compressor 30, condenser 21, pressure reducing device 22, and evaporator 23 are connected in this order in a ring shape by piping 24 through which the refrigerant gas flows, thereby forming a refrigeration cycle.

[0112] The configurations of the compressor 30, the condenser 21, the pressure reducing device 22, the evaporator 23, the piping 24, the main body housing, the blower, the operation unit, the control unit, etc. are not particularly limited, and known configurations can be suitably used. Furthermore, the refrigerator 20 may have known configurations other than those described above.

[0113] An example of the operation of refrigerator 20 shown in Fig. 3B will be described in detail. Compressor 30 compresses gas refrigerant and discharges it to condenser 21. Condenser 21 cools the gas refrigerant to liquid refrigerant. The liquid refrigerant is reduced in pressure by passing through pressure reducing device 22 and sent to evaporator 23. In evaporator 23, the liquid refrigerant absorbs heat from the surroundings and is vaporized as gas refrigerant, which returns to compressor 30. Compressor 30 compresses the gas refrigerant and discharges it again to condenser 21.

[0114] In such a refrigeration cycle system, the compressor 30 satisfies at least one of the following conditions, as described above: [Condition 1] the total cross-sectional area A of the rotor passages 43a is equal to or greater than the total cross-sectional area B of the rotor outer passages (A≧B); [Condition 2] the total heat transfer area C of the rotor passages 43a is equal to or greater than the total heat transfer area D of the rotor outer passages (C≧D); [Condition 3] the ratio C / S of the total heat transfer area C of the rotor passages 43a to the container cross-sectional area S of the sealed container 31 is 1.0 or greater (C / S≧1.0); and [Condition 4] the ratio (A+B) / S of the total cross-sectional area A+B of all the passages 43a, 44a, 44b to the container cross-sectional area S is 0.05 or greater ((A+B) / S≧0.05).

[0115] This makes it possible to give dominance to the rotor passage 43a, which is relatively less likely to propagate the disproportionation reaction, among all the passages provided in the motor section 41 of the compressor 30, and as a result, it is possible to effectively prevent the disproportionation reaction that occurs in the upper space 31a or the lower space 31b of the motor section 41 from propagating to the opposite space.

[0116] Furthermore, by suppressing the propagation of the disproportionation reaction, the cooling of the electric motor section 41, which is the main function of the passages 43a, 44a, and 44b, can calm and ultimately eliminate the disproportionation reaction itself. As a result, it is possible to effectively suppress or avoid the possibility of a large-scale disproportionation reaction occurring throughout the entire interior of the compressor 30. This further improves the reliability of the refrigeration cycle system including this compressor 30.

[0117] The present invention is not limited to the description of the above-described embodiments, and various modifications are possible within the scope of the claims. Embodiments obtained by appropriately combining the technical means disclosed in different embodiments or multiple modified examples are also included in the technical scope of the present invention.

[0118] Furthermore, many modifications and other embodiments of the present invention will be apparent to those skilled in the art from the above description. Therefore, the above description should be construed as illustrative only and is provided for the purpose of teaching those skilled in the art the best mode for carrying out the present invention. Details of the structure and / or function thereof may be substantially changed without departing from the spirit of the present invention.

[0119] (Additional Notes) Based on the descriptions of the above embodiments, the present specification discloses the following technologies: (Technology 1) A compressor that uses a working fluid for a refrigeration cycle that contains at least a hydrofluoroolefin as a refrigerant component, the compressor comprising: an electric motor unit having a rotor and a stator; a compression mechanism unit driven by the electric motor unit; and a sealed container that houses the electric motor unit and the compression mechanism unit, wherein spaces are provided above and below the electric motor unit within the sealed container, and the electric motor unit is provided with a plurality of passages that communicate the upper space with the lower space, and wherein, when the total cross-sectional area of ​​all the passages provided in the rotor is A and the total cross-sectional area of ​​all the passages provided other than the rotor is B, A≧B.

[0120] (Technology 2) A compressor using a working fluid for a refrigeration cycle containing at least a hydrofluoroolefin as a refrigerant component, the compressor comprising: an electric motor unit having a rotor and a stator; a compression mechanism unit driven by the electric motor unit; and a sealed container accommodating the electric motor unit and the compression mechanism unit therein; wherein spaces are provided above and below the electric motor unit within the sealed container; the electric motor unit is provided with a plurality of passages communicating the upper space with the lower space; and wherein the heat transfer area of ​​the passages is the product of the equivalent diameter d of the passages, the passage length L, and pi (π) (π × d × L), where C is the total heat transfer area of ​​all the passages provided in the rotor, and D is the total heat transfer area of ​​all the passages provided other than the rotor, and C is greater than or equal to D.

[0121] (Technology 3) A compressor using a working fluid for a refrigeration cycle containing at least a hydrofluoroolefin as a refrigerant component, the compressor comprising: an electric motor unit having a rotor and a stator; a compression mechanism unit driven by the electric motor unit; and a sealed container accommodating the electric motor unit and the compression mechanism unit therein; wherein spaces are provided above and below the electric motor unit within the sealed container; the electric motor unit is provided with a plurality of passages communicating the upper space with the lower space; the heat transfer area of ​​the passages is defined as the product of the equivalent diameter d of the passage, the passage length L, and pi (π × d × L), the total heat transfer area of ​​all the passages provided in the rotor is defined as C; and the cross-sectional area of ​​the sealed container based on the inner diameter of the sealed container is defined as S, where C / S is the ratio of the total heat transfer area C to the cross-sectional area S of 1.0 or more (C / S≧1.0).

[0122] (Technology 4) A compressor using a working fluid for a refrigeration cycle containing at least a hydrofluoroolefin as a refrigerant component, the compressor comprising: an electric motor unit having a rotor and a stator; a compression mechanism unit driven by the electric motor unit; and a sealed container accommodating the electric motor unit and the compression mechanism unit therein; wherein spaces are provided above and below the electric motor unit within the sealed container; the electric motor unit is provided with a plurality of passages connecting the upper space with the lower space; wherein a total cross-sectional area of ​​all the passages provided in the rotor is A, a total cross-sectional area of ​​all the passages provided other than the rotor is B, and further, a cross-sectional area of ​​the sealed container based on an inner diameter of the sealed container is S, and the ratio (A+B) / S of the total cross-sectional area (A+B) of all the passages to the cross-sectional area S of the sealed container is 0.05 or greater ((A+B) / S≧0.05).

[0123] (Technology 5) The compressor according to any one of Technologies 1 to 4, wherein the passage provided other than the rotor is at least one of an air gap passage formed between the rotor and the stator and a stator passage provided between the stator and the sealed container.

[0124] (Technology 6) The compressor according to any one of Techniques 1 to 5, wherein the hydrofluoroolefin is at least one of 1,1,2-trifluoroethylene (HFO1123) and 1,2-difluoroethylene (HFO1132).

[0125] (Technology 7) The compressor according to any one of Technologies 1 to 6, wherein the working fluid for a refrigeration cycle further contains difluoromethane as a refrigerant component and at least one of saturated hydrocarbons, haloalkanes, and fluoroalkanes having 1 to 3 carbon atoms and a boiling point of 0°C or less (excluding difluoromethane) as a disproportionation inhibitor.

[0126] (Technology 8) A refrigeration cycle system using a working fluid for a refrigeration cycle containing at least a hydrofluoroolefin as a refrigerant component, and including the compressor according to any one of Technologies 1 to 7.

[0127] The present invention can be suitably used in the field of compressors that use hydrofluoroolefins (HFOs) as a refrigerant component, and can also be suitably used widely in the field of refrigeration cycle systems that include such compressors, such as air conditioners, refrigerators (for home and commercial use), dehumidifiers, showcases, ice makers, heat pump water heaters, heat pump washer-dryers, and vending machines.

[0128] 10: Air conditioner (refrigeration cycle system) 11: Indoor unit 12: Outdoor unit 13: Piping 14: Heat exchanger 15: Heat exchanger 16: Pressure reducing device 17: Four-way valve 20: Refrigerator (refrigeration cycle system) 21: Condenser 22: Pressure reducing device 23: Evaporator 24: Piping 30: Compressor (rotary type) 31: Sealed container 31a: Upper space 31b: Lower space 32: Upper shell 33: Body shell 34: Lower shell 35: Discharge pipe 36: Suction pipe 41: Electric motor section (motor) 42: Compression mechanism section 43: Rotor 43a: Rotor passage 44: Stator 44a: Stator passage (rotor outer passage) 44b: Air gap passage (rotor outer passage) 45: Shaft 46: Piston 47: Cylinder 48: Lubricating oil

Claims

1. A compressor that uses a working medium for a refrigeration cycle containing at least a hydrofluoroolefin as a refrigerant component, comprising: an electric motor unit having a rotor and a stator; a compression mechanism unit driven by the electric motor unit; and a sealed container that houses the electric motor unit and the compression mechanism unit, wherein spaces are provided above and below the electric motor unit within the sealed container, and the electric motor unit is provided with a plurality of passages that communicate the upper space with the lower space, and wherein, when the total cross-sectional area of ​​all the passages provided in the rotor is A and the total cross-sectional area of ​​all the passages provided other than the rotor is B, A > B.

2. A compressor using a working medium for a refrigeration cycle containing at least a hydrofluoroolefin as a refrigerant component, comprising: an electric motor unit having a rotor and a stator; a compression mechanism unit driven by the electric motor unit; and an airtight container housing the electric motor unit and the compression mechanism unit therein; wherein spaces are provided above and below the electric motor unit within the airtight container; and the electric motor unit is provided with a plurality of passages communicating the upper space with the lower space, wherein the heat transfer area of ​​the passages is the product of the equivalent diameter d of the passages, the passage length L and pi (π x d x L), C is the total heat transfer area of ​​all the passages provided in the rotor, and D is the total heat transfer area of ​​all the passages provided other than the rotor, such that C ≧ D.

3. A compressor using a working medium for a refrigeration cycle containing at least a hydrofluoroolefin as a refrigerant component, comprising: an electric motor unit having a rotor and a stator; a compression mechanism unit driven by the electric motor unit; and a sealed container accommodating the electric motor unit and the compression mechanism unit therein; within the sealed container, spaces are provided above and below the electric motor unit, and the electric motor unit is provided with a plurality of passages connecting the upper space and the lower space, wherein the heat transfer area of ​​the passages is the product of the equivalent diameter d of the passages, the passage length L and pi (π x d x L), the total heat transfer area of ​​all the passages provided in the rotor is C, and the cross-sectional area of ​​the sealed container based on the inner diameter of the sealed container is S, wherein the ratio C / S of the total heat transfer area C to the cross-sectional area S is 1.0 or more (C / S ≧ 1.0).

4. A compressor using a working medium for a refrigeration cycle containing at least a hydrofluoroolefin as a refrigerant component, comprising: an electric motor unit having a rotor and a stator; a compression mechanism unit driven by the electric motor unit; and a sealed container accommodating the electric motor unit and the compression mechanism unit therein; within the sealed container, spaces are provided above and below the electric motor unit, and the electric motor unit is provided with a plurality of passages connecting the upper space and the lower space, wherein the total cross-sectional area of ​​all the passages provided in the rotor is A, the total cross-sectional area of ​​all the passages provided other than the rotor is B, and further, the cross-sectional area of ​​the sealed container based on the inside diameter of the sealed container is S, wherein the ratio (A+B) of the total cross-sectional area of ​​all the passages to the cross-sectional area S of the sealed container is 0.05 or more ((A+B) / S≧0.05).

5. A compressor as claimed in any one of claims 1 to 4, wherein the passage provided other than in the rotor is at least one of an air gap passage formed between the rotor and the stator, and a stator passage provided between the stator and the sealed container.

6. The compressor according to any one of claims 1 to 4, wherein the hydrofluoroolefin is at least one of 1,1,2-trifluoroethylene (HFO1123) and 1,2-difluoroethylene (HFO1132).

7. The compressor according to any one of claims 1 to 4, wherein the working fluid for a refrigeration cycle further contains difluoromethane as a refrigerant component, and contains at least one of saturated hydrocarbons, haloalkanes, and fluoroalkanes having 1 to 3 carbon atoms and a boiling point of 0°C or less (excluding difluoromethane) as a disproportionation inhibitor.

8. A refrigeration cycle system, comprising a working fluid for a refrigeration cycle containing at least a hydrofluoroolefin as a refrigerant component, and comprising a compressor according to any one of claims 1 to 4.

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