JP5304531B2 - Refrigeration equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent deterioration of resin functional components in a compressor of a refrigerating device using a refrigerant indicated by a molecular formula of C<SB>3</SB>H<SB>m</SB>F<SB>n</SB>(wherein, m and n are &ge;1 and &le;5 of integer numbers and a relationship of m+n=6 is achieved) and having one double bond in the molecular structure or a refrigerant mixture including the refrigerant. <P>SOLUTION: In the compressor (30), each bearing (41, 42, 43, 44) and an insulation material of an electric motor (85) are constituted as the resin functional components coming into contact with the refrigerant and refrigerating machine oil. In the refrigerating machine oil, an aniline point is &ge;-100&deg;C and &le;0&deg;C. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

    The present invention relates to a refrigeration apparatus that performs a refrigeration cycle by compressing refrigerant with a compressor, and particularly relates to measures for improving reliability.

    Conventionally, a refrigeration apparatus including a refrigerant circuit that performs a refrigeration cycle has been widely applied to an air conditioner, various cooling apparatuses, a water heater, and the like.

    Patent Document 1 discloses this type of refrigeration apparatus. This refrigeration apparatus includes a refrigerant circuit that is filled with a refrigerant to form a closed circuit. A compressor, a condenser, an expansion valve, and an evaporator are connected to the refrigerant circuit. When the compressor is operated, the refrigerant compressed by the compressor dissipates heat to the air and is condensed by the condenser. The refrigerant condensed in the condenser is depressurized by the expansion valve and then evaporated by the evaporator. The evaporated refrigerant is sucked into the compressor and compressed again.

Further, the refrigerant circuit of Patent Document 1 is expressed by a molecular formula: C ₃ H _m F _n (where m and n are integers of 1 to 5, and the relationship of m + n = 6 is established) and has a molecular structure. A refrigerant having one double bond therein is used. It is known that this refrigerant does not contain chlorine atoms or bromine atoms in its molecule and has a small influence on the destruction of the ozone layer.

JP-A-4-110388

    By the way, since the refrigerant | coolant currently disclosed by patent document 1 is a comparatively unstable molecular structure, such as having a double bond, a refrigerant | coolant deteriorates with a long-term refrigerating cycle, and an impurity etc. may be produced | generated. . When such impurities are generated, for example, resin functional parts such as a sliding member and a seal member of a movable scroll of a compressor are easily deteriorated due to the influence of the impurities. As a result, the durability and reliability of such functional parts may be impaired.

    Further, the compressor as disclosed in Patent Document 1 is provided with refrigerating machine oil for lubrication of each sliding portion. However, if the refrigerating machine oil is selected without considering the relationship with the resin functional parts, the functional parts may be denatured. For this reason, in combination with the generation of impurities and the like due to the deterioration of the refrigerant described above, there has been a problem that the deterioration of the functional parts made of resin becomes remarkable.

The present invention has been made in view of such points, and the object thereof is a molecular formula: C ₃ H _m F _n (where m and n are integers of 1 or more and 5 or less, and a relationship of m + n = 6 is established. )) And a refrigerant circuit using a refrigerant circuit in which a single refrigerant composed of a refrigerant having one double bond in the molecular structure or a mixed refrigerant containing the refrigerant is used. It is to suppress deterioration.

In the first invention, the refrigerant is circulated by the compressor (30) in which the predetermined resin functional parts (41, 42, 43, 44, 47) are arranged so as to be in contact with the refrigerant and the refrigeration oil. The refrigerant circuit (10) is provided, and the refrigerant of the refrigerant circuit (10) has a molecular formula: C ₃ H _m F _n (where m and n are integers of 1 to 5, and the relationship m + n = 6 is established. )) And a refrigerating apparatus in which a refrigerant having one double bond in the molecular structure or a mixed refrigerant containing the refrigerant is used. And the refrigerating machine oil of the said compressor (30) is an aniline point of -100 degreeC or more and 0 degrees C or less.

    In the first aspect of the invention, the vapor compression refrigeration cycle is performed by circulating the refrigerant in the refrigerant circuit (10). In the compressor (30), predetermined resin functional parts (41, 42, 43, 44, 47) that are in contact with the refrigerant and the refrigerating machine oil are disposed. If the aniline point of the refrigerating machine oil is too low, the refrigerating machine oil swells the resin functional parts (41, 42, 43, 44, 47). Conversely, if the aniline point of the refrigerating machine oil is too high, the refrigerating machine oil contracts the resin functional parts (41, 42, 43, 44, 47). That is, the resin functional parts (41, 42, 43, 44, 47) are denatured / deteriorated by the refrigerating machine oil. Therefore, in the present invention, a refrigerating machine oil having an aniline point in a predetermined range (−100 ° C. to 0 ° C.) in which the resin functional parts (41, 42, 43, 44, 47) do not swell and contract is used.

    According to a second invention, in the first invention, the resin functional component is configured by a sliding member (41, 42, 43, 44) provided at a predetermined sliding portion of the compressor (30). Yes. The sliding members (41, 42, 43, 44) are made of polytetrafluoroethylene, polyphenylene sulfide, or polyamide resin.

    In the second aspect of the invention, the sliding members (41, 42, 43, 44) provided at the sliding portion in the compressor (30) constitute a resin functional part. The sliding members (41, 42, 43, 44) are made of any of polytetrafluoroethylene, polyphenylene sulfide, and polyamide resin. These resin materials have a relatively high stability against impurities generated from the refrigerant. Therefore, the sliding member (41, 42, 43, 44) is prevented from being denatured / deteriorated due to the influence of impurities generated from the refrigerant.

    According to a third aspect, in the first aspect, the resin functional component is configured by a seal member (47) for preventing refrigerant from leaking through a predetermined gap in the compressor (30). The seal member (47) is made of any of polytetrafluoroethylene, polyphenylene sulfide, chloroprene rubber, silicon rubber, hydrogenated nitrile rubber, fluorine rubber, and hydrin rubber.

    In the third aspect of the invention, in the third aspect of the invention, the sealing member (47) for preventing the leakage of the refrigerant in the predetermined gap constitutes the resin functional part. The sealing member (47) is made of any of polyphenylene sulfide, chloroprene rubber, silicon rubber, hydrogenated nitrile rubber, fluorinated rubber, and hydrin rubber. For this reason, it is suppressed that a sealing member (47) denatures / deteriorates by the influence of the impurity produced | generated from the refrigerant | coolant.

    According to a fourth invention, in the first invention, the fluid machine (82) in which the compressor (30) compresses the refrigerant, and the electric motor (85) in which the insulating material is made of resin and drives the fluid machine (82). ). And the said resin functional parts are comprised with the insulating material of the said electric motor (85).

    In the fourth aspect of the invention, in the compressor (30), the resin insulating material of the electric motor (85) constitutes a resin functional component. In the compressor (30), since refrigeration oil having an aniline point in a predetermined range is used, the insulating material of the electric motor (85) does not swell / shrink with the refrigeration oil. Therefore, the modification / deterioration of the insulating material of the electric motor (85) is suppressed.

    According to a fifth invention, in any one of the first to fourth inventions, the refrigerating machine oil has a saturated water content of 2000 ppm or more at a temperature of 30 ° C. and a relative humidity of 90%.

    In the fifth aspect of the invention, in the compressor (30), a refrigerating machine oil having a saturated water content of 2000 ppm or more under conditions of a temperature of 30 ° C. and a relative humidity of 90% is used. That is, in the present invention, refrigerating machine oil having a relatively high hygroscopic property is used. Thereby, the water | moisture content in a refrigerant | coolant can be capture | acquired by refrigerating machine oil. As a result, deterioration due to the influence of moisture is suppressed in the refrigerant.

    In a sixth aspect based on the fifth aspect, the refrigerating machine oil is mainly composed of at least one of polyalkylene glycol, polyol ester and polyvinyl ether.

    In the sixth aspect of the invention, the compressor (30) uses refrigeration oil mainly composed of at least one of polyalkylene glycol, polyol ester, and polyvinyl ether. Since these refrigerating machine oils are compatible with the refrigerant represented by the above molecular formula and having one double bond in the molecular structure, the refrigerant is easily dissolved in the refrigerating machine oil.

    According to a seventh invention, in the fifth or sixth invention, the refrigerating machine oil has a kinematic viscosity of 30 cSt or more and 400 cSt or less at 40 ° C. and a pour point of −30 ° C. or less.

    In the seventh invention, since the kinematic viscosity of the refrigerating machine oil is 400 cSt or less at 40 ° C., the refrigerant is dissolved to some extent in the refrigerating machine oil. Further, since the kinematic viscosity of the refrigerating machine oil is 30 cSt or higher at 40 ° C., the kinematic viscosity is not too low and the oil film strength is not insufficient, and the lubrication performance of the sliding portion is ensured.

    Furthermore, in the said 7th invention, the refrigerating machine oil whose pour point is -30 degrees C or less is provided in a compressor (30). If the pour point of the refrigerating machine oil is higher than −30 ° C., the refrigerating machine oil may not easily flow even in a portion of the refrigerating apparatus (20) that is at a low temperature during operation. If the fluidity of the refrigerating machine oil decreases, the supply amount of the refrigerating machine oil to the sliding part decreases, and the sliding part becomes insufficiently lubricated. Moreover, if the supply amount of the refrigerating machine oil to the sliding portion is reduced, the oil film strength at the sliding portion may be insufficient, leading to abnormal wear and seizure. Therefore, in the present invention, refrigerating machine oil having a pour point of −30 ° C. or lower is used.

    In an eighth invention according to any one of the fifth to seventh inventions, the refrigerating machine oil has a surface tension of 0.02 N / m or more and 0.04 N / m or less at 20 ° C.

    In the said 8th invention, the surface tension of refrigeration oil will be 0.02 N / m or more and 0.04 N / m or less in 20 degreeC. Here, if the surface tension of the refrigerating machine oil is too small, the refrigerating machine oil tends to become small oil droplets in the gas refrigerant in the compressor (30), and a relatively large amount of refrigerating machine oil is discharged from the compressor (30) together with the refrigerant. Will be. Therefore, there is a possibility that oil rises in the compressor (30). Conversely, if the surface tension of the refrigeration oil is too large, the refrigeration oil discharged from the compressor (30) tends to be large oil droplets in the refrigerant circuit (10). For this reason, the refrigerating machine oil discharged from the compressor (30) is not pushed away by the refrigerant and hardly returns to the compressor (30). As a result, even in this case, there is a possibility that oil rises in the compressor (30). Therefore, in the present invention, by setting the surface tension of the refrigerating machine oil within a predetermined range, the size of the oil droplet is optimized, and the above-described oil rise is avoided.

    According to a ninth invention, in any one of the fifth to eighth inventions, the refrigerating machine oil has a chlorine concentration of 50 ppm or less.

    In the ninth aspect of the invention, since the chlorine concentration of the refrigerating machine oil is 50 ppm or less, the deterioration of the refrigerant due to chlorine is suppressed. Thereby, the production | generation of an impurity is also suppressed and deterioration of the resin functional parts (41, 42, 43, 44, 47) is suppressed.

    In a tenth aspect based on any one of the fifth to ninth aspects, the refrigerating machine oil has a sulfur concentration of 50 ppm or less.

    In the tenth aspect, since the sulfur concentration of the refrigerating machine oil is 50 ppm or less, deterioration of the refrigerant due to sulfur is suppressed. Thereby, the production | generation of an impurity is also suppressed and deterioration of the resin functional parts (41, 42, 43, 44, 47) is suppressed.

    In an eleventh aspect of the invention, in any one of the fifth to tenth aspects of the invention, the refrigerating machine oil includes an acid scavenger, an extreme pressure additive, an antioxidant, an oxygen scavenger, an antifoaming agent, an oil agent, and Among the copper deactivators, at least one additive is added.

    In the eleventh aspect of the invention, at least one additive among the acid scavenger, extreme pressure additive, antioxidant, oxygen scavenger, defoamer, oiliness agent and copper deactivator is refrigerator oil. Included. For this reason, refrigerating machine oil and a refrigerant | coolant are stabilized and the production | generation of an impurity etc. is suppressed.

    In a twelfth aspect according to the eleventh aspect, in the above refrigerating machine oil, when one kind of additive is added, the ratio of the additive is 0.01 mass% or more and 5 mass% or less. When various types of additives are added, the ratio of each additive is 0.01% by mass or more and 5% by mass or less.

    In the twelfth aspect, when one kind of additive is added to the refrigerating machine oil, the ratio of the additive in the refrigerating machine oil is 0.01% by mass or more and 5% by mass or less. When plural types of additives are added to the refrigerating machine oil, the proportion of any additive in the refrigerating machine oil is 0.01% by mass or more and 5% by mass or less.

In a thirteenth aspect of the present invention based on any one of the first to twelfth aspects of the present invention, the molecular formula: C ₃ H _m F _n (where m and n are integers of 1 or more and 5 or less, and a relationship of m + n = 6 is established. And the refrigerant having one double bond in the molecular structure is 2,3,3,3-tetrafluoro-1-propene.

    In the thirteenth aspect, the refrigerant of the refrigerant circuit (10) is a single refrigerant composed of 2,3,3,3-tetrafluoro-1-propene, or 2,3,3,3-tetrafluoro-1- A mixed refrigerant containing propene is used.

In a fourteenth aspect based on any one of the first to thirteenth aspects, the refrigerant of the refrigerant circuit (10) is the molecular formula: C ₃ H _m F _n (where m and n are 1 or more and 5 or less). And the relationship of m + n = 6 is established.) And is a mixed refrigerant including a refrigerant having one double bond in the molecular structure and difluoromethane.

    In the fourteenth aspect of the invention, as the refrigerant of the refrigerant circuit (10), a mixed refrigerant containing difluoromethane and a refrigerant represented by the molecular formula and having one double bond in the molecular structure is used. Here, the refrigerant represented by the above molecular formula and having one double bond in the molecular structure is a so-called low-pressure refrigerant. For this reason, for example, when a single refrigerant composed of a refrigerant represented by the above molecular formula and having one double bond in the molecular structure is used, the influence of the refrigerant pressure loss on the operating efficiency of the refrigeration apparatus is relatively large. Therefore, the actual driving efficiency is lowered with respect to the theoretical driving efficiency. Therefore, in the present invention, difluoromethane, which is a so-called high-pressure refrigerant, is added to the refrigerant represented by the above molecular formula and having one double bond in the molecular structure.

In a fifteenth aspect based on any one of the first to thirteenth aspects, the refrigerant of the refrigerant circuit (10) is the molecular formula: C ₃ H _m F _n (where m and n are 1 or more and 5 or less). And the relationship of m + n = 6 is established.) And a refrigerant mixture including pentafluoroethane and a refrigerant having one double bond in the molecular structure.

    In the fifteenth aspect of the invention, as the refrigerant of the refrigerant circuit (10), a mixed refrigerant containing a refrigerant represented by the molecular formula and having one double bond in the molecular structure and pentafluoroethane is used. Here, the refrigerant represented by the above molecular formula and having one double bond in the molecular structure is a slightly flammable refrigerant, but is not without the risk of ignition. Therefore, in the present invention, pentafluoroethane, which is a flame retardant refrigerant, is added to the refrigerant represented by the above molecular formula and having one double bond in the molecular structure.

    As described above, according to the present invention, since the refrigerating machine oil having an aniline point of −100 ° C. or higher and 0 ° C. or lower is used, the resin functional parts (41, 42, 43, 44, 47) are swollen by the refrigerating machine oil. / It can suppress shrinking. Therefore, at least denaturation / degradation of the resin functional parts (41, 42, 43, 44, 47) due to the refrigerating machine oil can be suppressed. As a result, the durability of the resin functional parts (41, 42, 43, 44, 47) is improved, and the reliability of the compressor (30) or the refrigeration apparatus is improved.

    In the second invention, the sliding member (41, 42, 43, 44) as the resin functional component is made of any of polytetrafluoroethylene, polyphenylene sulfide, and polyamide resin. Thereby, modification | denaturation / deterioration of the sliding member (41, 42, 43, 44) resulting from the impurity produced | generated from a refrigerant | coolant can be suppressed. That is, it is possible to suppress deterioration of the sliding members (41, 42, 43, 44) due to the refrigerant as well as the refrigerator oil. Therefore, the durability of the sliding member (41, 42, 43, 44) is further improved, and desired sliding property / abrasion resistance can be obtained in the sliding member (41, 42, 43, 44).

    In the third aspect of the invention, the sealing member (47) as a resin functional part is composed of any of polytetrafluoroethylene, polyphenylene sulfide, chloroprene rubber, silicon rubber, hydrogenated nitrile rubber, fluorine rubber, and hydrin rubber. Yes. Thereby, denaturation / deterioration of the seal member (47) due to impurities generated from the refrigerant can be avoided. That is, it is possible to suppress deterioration of the seal member (47) due to the refrigerant as well as the refrigerator oil. Therefore, the durability of the sealing member (47) is further improved, and a desired sealing property can be obtained in the sealing member (47).

    Moreover, in 4th invention, although the insulating material of the electric motor (85) of a compressor (30) is comprised with resin, it can suppress that the insulating material swells / shrinks with refrigerating machine oil. When the insulating material swells, its insulating property decreases, but it can be suppressed. Further, when the insulating material shrinks and the hardness increases, the insulating material is easily damaged by vibration of the compressor (30). In this case, the insulating property is also lowered, but this can be suppressed. Thus, in this invention, it can suppress that resin-made insulating material denatures in an electric motor (85). As a result, the durability of the electric motor (85) is improved.

    Further, according to the fifth invention, since the refrigerating machine oil having a saturated water content of 2000 ppm or more at a temperature of 30 ° C. and a relative humidity of 90% is used, the water in the refrigerant can be captured by the refrigerating machine oil. For this reason, it can prevent that a refrigerant | coolant will deteriorate by the influence of a water | moisture content.

    According to the sixth aspect of the invention, since the refrigerating machine oil containing at least one of polyalkylene glycol, polyol ester, and polyvinyl ether as a main component is used, the refrigerant and the refrigerating machine oil are easily dissolved in each other. Therefore, even if the refrigeration oil flows out into the refrigerant circuit (10), the refrigeration oil easily dissolves in the refrigerant and returns to the compressor (30). As a result, oil rising in the compressor (30) can be suppressed, and the reliability of the refrigeration apparatus can be improved.

    Further, according to the seventh invention, since the kinematic viscosity of the refrigerating machine oil is set to 30 cSt or more and 400 cSt or less at 40 ° C., sufficient lubrication performance of the sliding portion can be ensured. Furthermore, since the pour point of the refrigerating machine oil is set to −30 ° C. or lower, the flowability of the refrigerating machine oil can be ensured even at a relatively low temperature portion in the refrigerant circuit (10). Thereby, the supply amount of refrigeration oil and the oil film strength can be sufficiently ensured in the sliding portion of the compressor (30). As a result, the lubricating performance in the compressor (30) is further improved.

    According to the eighth invention, since the surface tension of the refrigeration oil is set to 0.02 N / m or more and 0.04 N / m or less at 20 ° C., the size of the oil droplets of the refrigeration oil can be optimized. Accordingly, a large amount of refrigeration oil is not discharged from the compressor (30) of the refrigeration oil, and the refrigeration oil discharged from the compressor (30) does not easily return to the compressor (30). As a result, oil rise can be suppressed in the compressor (30), and poor lubrication can be prevented.

    Moreover, according to the ninth aspect, since the chlorine concentration of the refrigerating machine oil is set to 50 ppm or less, it is possible to prevent the deterioration of the refrigerant due to chlorine. As a result, the durability of the resin functional parts (41, 42, 43, 44, 47) can be further improved.

    Furthermore, according to the tenth invention, since the sulfur concentration of the refrigerating machine oil is set to 50 ppm or less, it is possible to prevent the deterioration of the refrigerant from being accelerated due to the sulfur. As a result, the durability of the resin functional parts (41, 42, 43, 44, 47) can be further improved.

    According to the eleventh and twelfth inventions, at least one of six types of additives, that is, an acid scavenger, an extreme pressure additive, an antioxidant, an antifoaming agent, an oily agent, and a copper deactivator. Since the additive is added to the refrigerating machine oil, the refrigerant and the refrigerating machine oil can be stabilized. As a result, the generation of impurities can be suppressed, and the durability / reliability of the resin functional parts (41, 42, 43, 44, 47) is further improved.

    According to the fourteenth aspect of the invention, since difluoromethane as a so-called high-pressure refrigerant is added to the refrigerant represented by the above molecular formula and having one double bond in the molecular structure, the refrigerant pressure loss is reduced. The influence on the driving efficiency can be reduced. As a result, the actual operating efficiency of the refrigeration apparatus can be improved.

    According to the fifteenth aspect of the present invention, since pentafluoroethane as a flame retardant refrigerant is added to the refrigerant represented by the molecular formula and having one double bond in the molecular structure, the refrigerant circuit (10 ) Is difficult to burn. As a result, the reliability of the refrigeration apparatus can be improved.

FIG. 1 is a refrigerant circuit diagram illustrating a schematic configuration of a refrigeration apparatus according to an embodiment. FIG. 2 is a longitudinal sectional view of the compressor according to the embodiment. FIG. 3 is a cross-sectional view of the compression mechanism showing the main part of the compressor according to the embodiment. FIG. 4 is a longitudinal sectional view of a compressor according to Modification 3 of the embodiment.

    Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The following embodiments are essentially preferable examples, and are not intended to limit the scope of the present invention, its application, or its use.

    This embodiment is an air conditioner (20) configured by a refrigeration apparatus according to the present invention. As shown in FIG. 1, the air conditioner (20) includes an outdoor unit (22) and three indoor units (23a, 23b, 23c). The number of indoor units (23) is merely an example.

    The air conditioner (20) includes a refrigerant circuit (10) that is filled with a refrigerant and performs a refrigeration cycle. The refrigerant circuit (10) includes an outdoor circuit (9) accommodated in the outdoor unit (22), and indoor circuits (17a, 17b, 17c) accommodated in the indoor units (23a, 23b, 23c). Yes. These indoor circuits (17a, 17b, 17c) are connected to the outdoor circuit (9) via the liquid side connecting pipe (18) and the gas side connecting pipe (19). These indoor circuits (17a, 17b, 17c) are connected in parallel to each other.

The refrigerant filled in the refrigerant circuit (10) of the present embodiment is a single component composed of only 2,3,3,3-tetrafluoro-1-propene (hereinafter referred to as “HFO-1234yf”). It is a refrigerant (single refrigerant). Note that the chemical formula of HFO-1234yf is represented by CF ₃ —CF═CH ₂ and has one double bond in the molecular structure.

<Configuration of outdoor circuit>
The outdoor circuit (9) is provided with a compressor (30), an outdoor heat exchanger (11), an outdoor expansion valve (12), and a four-way switching valve (13).

    The compressor (30) is a fully enclosed type in which a compression mechanism (82) and an electric motor (85) are accommodated in a casing (70). The detailed structure of the compressor (30) will be described later. Electric power is supplied to the electric motor (85) of the compressor (30) via an inverter. The operating capacity of the compressor (30) is changed by changing the rotational speed of the electric motor (85). The compressor (30) has a discharge side connected to the second port (P2) of the four-way switching valve (13) and a suction side connected to the first port (P1) of the four-way switching valve (13).

    The outdoor heat exchanger (11) is a cross fin type fin-and-tube heat exchanger. An outdoor fan (14) is provided in the vicinity of the outdoor heat exchanger (11). In the outdoor heat exchanger (11), heat is exchanged between the outdoor air and the refrigerant. One end of the outdoor heat exchanger (11) is connected to the third port (P3) of the four-way switching valve (13), and the other end is connected to the outdoor expansion valve (12). The fourth port (P4) of the four-way switching valve (13) is connected to the gas side communication pipe (19).

    The outdoor expansion valve (12) is provided between the outdoor heat exchanger (11) and the liquid side end of the outdoor circuit (9). The outdoor expansion valve (12) is an electronic expansion valve with a variable opening.

    The four-way selector valve (13) is in a first state in which the first port (P1) and the fourth port (P4) communicate with each other and the second port (P2) and the third port (P3) communicate with each other (see FIG. 1 is shown by a solid line), the second port (P1) and the third port (P3) communicate with each other, and the second port (P2) and the fourth port (P4) communicate with each other (FIG. 1). The state indicated by a broken line in FIG.

<Indoor circuit configuration>
Each indoor circuit (17a, 17b, 17c) has an indoor heat exchanger (15a, 15b, 15c) and an indoor expansion valve (16a, 16b, 16c) in order from the gas side end to the liquid side end. And are provided.

    The indoor heat exchangers (15a, 15b, 15c) are cross-fin type fin-and-tube heat exchangers. Indoor fans (21a, 21b, 21c) are provided in the vicinity of the indoor heat exchangers (15a, 15b, 15c). In each indoor heat exchanger (15a, 15b, 15c), heat is exchanged between the indoor air and the refrigerant. Each indoor expansion valve (16a, 16b, 16c) is an electronic expansion valve having a variable opening.

<Compressor configuration>
The compressor (30) is a hermetic high-pressure dome type scroll compressor. Here, the configuration of the compressor (30) will be described with reference to FIG. 2 and FIG.

    The compressor (30) includes a casing (70) which is a so-called vertical closed container. In the casing (70), a lower bearing member (86), an electric motor (85), and a compression mechanism (82) are arranged in order from the bottom to the top.

    The electric motor (85) includes a stator (83) and a rotor (84). The stator (83) is fixed to the body of the casing (70). On the other hand, the rotor (84) is disposed inside the stator (83). Further, the crankshaft (60) of the compression mechanism (82) is connected to the rotor (84). The crankshaft (60) is inserted through the rotor (84) so as to be coaxial with the rotor (84).

    The compression mechanism (82) includes a movable scroll (76), a fixed scroll (75), a crankshaft (60) as a drive shaft, and a housing (77), and constitutes a fluid machine according to the present invention. ing.

    The crankshaft (60) includes a main shaft portion (61) and an eccentric portion (65). The main shaft portion (61) includes an intermediate portion (62), a large diameter portion (63), and a small diameter portion (64) that are arranged coaxially with each other. The large diameter part (63) is formed continuously at the upper end of the intermediate part (62). The outer diameter of the large diameter portion (63) is larger than the outer diameter of the intermediate portion (62). The small diameter part (64) is formed continuously at the lower end of the intermediate part (62). The outer diameter of the small diameter part (64) is smaller than the outer diameter of the intermediate part (62). The eccentric part (65) is a cylindrical part formed continuously at the upper end of the large diameter part (63) of the main shaft part (61). The shaft center of the eccentric part (65) is eccentric with respect to the shaft center of the main shaft part (61).

    The movable scroll (76) includes a substantially disc-shaped movable side end plate (76b) and a spiral movable side wrap (76a). The movable side wrap (76a) is erected on the front surface (upper surface) of the movable side end plate (76b). In addition, a cylindrical tubular protrusion (76c) is erected on the back surface (lower surface) of the movable side end plate (76b).

    An upper bearing (41) formed in a cylindrical shape is fitted into the cylindrical protrusion (76c) of the movable scroll (76). The eccentric part (65) of the crankshaft (60) is inserted into the upper bearing (41). The inner peripheral surface of the upper bearing (41) is in sliding contact with the outer peripheral surface of the eccentric portion (65). The cylindrical projection (76c) and the upper bearing (41) constitute an upper journal bearing (31) that supports the eccentric portion (65) of the crankshaft (60). The movable scroll (76) is supported by the housing (77) disposed below the movable scroll (76) via the Oldham ring (79).

    On the other hand, the fixed scroll (75) includes a substantially disc-shaped fixed side end plate (75b) and a spiral fixed side wrap (75a). The fixed side wrap (75a) is erected on the front surface (lower surface) of the fixed side end plate (75b).

    In the compression mechanism (82), the fixed-side wrap (75a) and the movable-side wrap (76a) mesh with each other, so that a plurality of compression chambers (73a, 73b) are provided between the contact portions of both wraps (75a, 76a). Is formed. Specifically, in the compression mechanism (82), the first compression chamber (73a) configured between the inner peripheral surface of the fixed wrap (75a) and the outer peripheral surface of the movable wrap (76a), and the fixed wrap A second compression chamber (73b) is formed between the outer peripheral surface of (75a) and the inner peripheral surface of the movable wrap (76a).

    In the compression mechanism (82) of the present embodiment, a so-called asymmetric spiral structure is adopted (see FIG. 3). That is, in this compression mechanism (82), the number of turns (the length of the spiral) is different between the fixed side wrap (75a) and the movable side wrap (76a).

    In the compression mechanism (82), a suction port (98) is formed at the outer edge of the fixed scroll (75). A suction pipe (57) penetrating the top of the casing (70) is connected to the suction port (98). The suction port (98) intermittently communicates with each of the first compression chamber (73a) and the second compression chamber (73b) as the movable scroll (76) revolves. The suction port (98) is provided with a suction check valve (not shown) that blocks the flow of refrigerant returning from the compression chamber (73) to the suction pipe (57).

    Further, in the compression mechanism (82), a discharge port (93) is formed at the center of the fixed side end plate (75b). The discharge port (93) intermittently communicates with each of the first compression chamber (73a) and the second compression chamber (73b) as the movable scroll (76) revolves. The discharge port (93) opens into a muffler space (96) formed above the fixed scroll (75).

    The housing (77) includes a main body (77a) and a bulging portion (77b). The main body portion (77a) is formed in a thick disk shape, and its outer peripheral surface is in close contact with the inner peripheral surface of the body portion of the casing (70). Moreover, the center part of the upper surface of the main body (77a) is depressed, and the cylindrical protrusion (76c) of the movable scroll (76) is inserted into the depression. A portion of the upper surface of the main body (77a) where the back surface of the movable side end plate (76b) of the movable scroll (76) is in sliding contact constitutes a thrust bearing (44). The bulging portion (77b) is formed at the center of the lower surface of the main body portion (77a), and bulges downward from the lower surface of the main body portion (77a). The bulge portion (77b) is formed with a through hole (77c) that penetrates the bulge portion (77b) up and down.

    A cylindrical intermediate bearing (42) is fitted in the through hole (77c) of the housing (77). A large diameter portion (63) of the crankshaft (60) is inserted through the intermediate bearing (42). The inner peripheral surface of the intermediate bearing (42) is in sliding contact with the outer peripheral surface of the large diameter portion (63). The bulging portion (77b) and the intermediate bearing (42) of the housing (77) constitute an intermediate journal bearing portion (32) that supports the large diameter portion (63) of the crankshaft (60).

    The internal space of the casing (70) is partitioned up and down by a housing (77). In the internal space of the casing (70), the upper side of the housing (77) is the suction space (101), and the lower side of the housing (77) is the discharge space (100). The suction space (101) communicates with the suction port (98) through a communication port (not shown). The discharge space (100) communicates with the muffler space (96) through a communication passage (103) formed between the fixed scroll (75) and the housing (77). Since the refrigerant discharged from the discharge port (93) flows in through the muffler space (96), the discharge space (100) during operation becomes a high-pressure space filled with the refrigerant compressed by the compression mechanism (82). In the discharge space (100), a discharge pipe (56) penetrating the body of the casing (70) is opened.

    The lower bearing member (86) includes a cylindrical portion (87) and an arm portion (88). The cylindrical portion (87) is formed in a thick cylindrical shape with both ends opened. The lower bearing member (86) is provided with three arm portions (88) radially. Each arm portion (88) extends outward from the outer peripheral surface of the cylindrical portion (87), and its protruding end surface is in close contact with the inner peripheral surface of the trunk portion of the casing (70).

    A cylindrical lower portion (43) is fitted into the cylindrical portion (87) of the lower bearing member (86). A small diameter portion (64) of the crankshaft (60) is inserted through the lower bearing (43). The inner peripheral surface of the lower bearing (43) is in sliding contact with the outer peripheral surface of the small diameter portion (64). The cylindrical portion (87) and the lower bearing (43) of the lower bearing member (86) constitute a lower journal bearing portion (33) that supports the small diameter portion (64) of the crankshaft (60).

    An oil sump for storing refrigeration oil is formed at the bottom of the casing (70). A first oil supply passage (104) communicating with the oil sump is formed inside the crankshaft (60), and a movable end plate (76b) of the movable scroll (76) is connected to the first oil supply passage (104). A second oil supply passage (105) is formed. Refrigerating machine oil in the oil reservoir is supplied to sliding parts such as journal bearing parts (31, 32, 33) and thrust bearings (64) through the first oil supply passage (104) and the second oil supply passage (105). .

    In the compressor (30), the insulating material of the upper bearing (41), the intermediate bearing (42), the lower bearing (43), the thrust bearing (44) and the electric motor (85) is the resin functional part according to the present invention. ing. These resin functional parts are disposed so as to be able to contact the refrigerant and the refrigerating machine oil.

    Each of the bearings (41, 42, 43, 44) constitutes a sliding member according to the present invention. Each of these bearings (41, 42, 43, 44) is made of any of polytetrafluoroethylene (PTFE), polyphenylene sulfide, and polyamide resin.

    The insulating material of the electric motor (85) is an insulating coating material or an insulating film for the winding of the stator (83). These insulating clothing materials and insulating films are resins that are not physically or chemically modified by the refrigerant, even when in contact with high-temperature and high-pressure refrigerant, especially solvent resistance, extraction resistance, thermal and chemical stability. A resin having foam resistance is used.

    Specifically, any of polyvinyl formal, polyester, THEIC-modified polyester, polyamide, polyamideimide, polyesterimide, and polyesteramideimide is used as the insulating coating material for the winding of the stator (83). It is preferable to use a double coated wire in which the upper layer is polyamideimide and the lower layer is polyesterimide. In addition to the above substances, an enamel coating having a glass transition temperature of 120 ° C. or higher may be used.

    In addition, any one of polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyphenylene sulfide (PPS), and polybutylene terephthalate (PBT) is used for the insulating film. In addition, it is also possible to use the same foam film as the refrigerant of the refrigeration cycle for the insulating film. Polyether ether ketone (PEEK) or liquid crystal polymer (LCP) is used as an insulating material for holding a winding such as an insulator. Epoxy resin is used for the varnish.

<Refrigerator oil>
In this embodiment, it is possible to use a refrigerating machine oil whose main component is at least one of three types of base oils of polyalkylene glycol, polyol ester and polyvinyl ether for the compressor (30). For example, the refrigerating machine oil of this embodiment uses a refrigerating machine oil mainly composed of only polyvinyl ether among these three types.

    In the refrigerating machine oil of the present embodiment, a refrigerating machine oil mainly composed of polyvinyl ether having a structural unit represented by the following general formula (I) is used. Among the polyvinyl ethers, the polyvinyl ether having this structure is excellent in compatibility with the refrigerant represented by the molecular formula 1 and having one double bond in the molecular structure.

    In the general formula (I), R1, R2 and R3 represent hydrogen or a hydrocarbon group having 1 to 8 carbon atoms. R1, R2 and R3 may be the same or different from each other. In the general formula (I), R4 is 40% or more and 100% or less of an alkyl group having 1 or 2 carbon atoms, and 0 or more and 60% or less of an alkyl group having 3 or 4 carbon atoms, for each structural unit. The composition ratio is as follows.

    The refrigerating machine oil has an aniline point of −100 ° C. or higher and 0 ° C. or lower. Here, the “aniline point” is a numerical value indicating the solubility of, for example, a hydrocarbon solvent, and when the sample (here, refrigerating machine oil) is mixed with an equal volume of aniline and cooled, it cannot be dissolved together. This represents the temperature when turbidity starts to appear (specified in JIS K 2256). In addition, these values are values of the refrigeration oil itself in a state where the refrigerant is not dissolved. This also applies to the refrigerating machine oil described in Modification 1 and Modification 2 described later and other embodiments.

By setting the aniline point in this manner, the compatibility between the insulating material of the bearings (41, 42, 43, 44) and the electric motor (85) constituting the above-described resin functional parts and the refrigerating machine oil is improved. Specifically, if the aniline point is too low, the refrigerating machine oil easily penetrates into the bearing (41, 42, 43, 44) and the insulating material, and the bearing (41, 42, 43, 44) and the like easily swell. On the other hand, if the aniline point is too high, the refrigerating machine oil hardly penetrates into the bearing (41, 42, 43, 44) and the insulating material, and the bearing (41, 42, 43, 44) and the like easily contract. Therefore, by setting the aniline point of the refrigerating machine oil within the predetermined range (−100 ° C. or more and 0 ° C. or less), the swelling / shrinkage deformation of the bearing (41, 42, 43, 44) and the insulating material can be prevented. it can. Here, if each bearing (41, 42, 43, 44) swells and deforms, the gap (gap) at the sliding portion cannot be maintained at a desired length. As a result, there is a possibility rather invited an increase in sliding resistance. When each bearing (41,42,43,44) shrinks and deforms, the hardness of the bearing (41,42,43,44) increases and the vibration of the compressor (30) causes the bearing (41,42,43,44) 44) may be damaged. That is, when the bearings (41, 42, 43, 44) are contracted and deformed, there is a possibility that the rigidity of the sliding portion is lowered. Further, when the insulating material (insulating clothing material, insulating film, etc.) of the electric motor (85) is swelled and deformed, the insulating property of the insulating material is lowered. If the insulating material shrinks and deforms, the insulating material may be damaged as in the case of the above-described bearings (41, 42, 43, 44). In this case, the insulating property is also lowered. However, since the aniline point of the refrigerating machine oil is set within the predetermined range as described above, the swelling / shrinkage deformation of the bearing (41, 42, 43, 44) and the insulating material can be suppressed. be able to.

The refrigerating machine oil has a kinematic viscosity of 30 cSt or more and 400 cSt or less at 40 ° C., a pour point of −30 ° C. or less, a surface tension of 0.02 N / m or more and 0.04 N / m or less at 20 ° C., and a density. There has been a 0.8 g / cm ³ or more 1.8 g / cm ³ or less at 15 ° C.. The pour point value is obtained by the test method defined in “JIS K 2269”. The refrigeration oil has a saturated water content of 2000 ppm or more at a temperature of 30 ° C. and a relative humidity of 90%. Further, in the refrigerating machine oil, the concentration of chlorine contained therein is 50 ppm or less, and the concentration of sulfur contained therein is 50 ppm or less. In addition, the physical property value of these refrigerating machine oil is the same also about the refrigerating machine oil described in the modified example mentioned later and other embodiment. These physical property values are values of the refrigerating machine oil itself in a state where the refrigerant is not dissolved.

    In the present embodiment, the polyvinyl ether that is the main component of the refrigerating machine oil is compatible with HFO-1234yf. The kinematic viscosity of the refrigerating machine oil is 400 cSt or less at 40 ° C. For this reason, HFO-1234yf dissolves to some extent in refrigeration oil. Moreover, since the pour point of the refrigeration oil is −30 ° C. or less, the fluidity of the refrigeration oil can be secured even at a low temperature portion in the refrigerant circuit (10). Further, since the surface tension is 0.04 N / m or less at 20 ° C., it is difficult for the refrigerating machine oil discharged from the compressor (30) to become large oil droplets that are difficult to be washed away by the refrigerant. Accordingly, the refrigerating machine oil discharged from the compressor (30) is dissolved in HFO-1234yf and returns to the compressor (30) together with HFO-1234yf. Therefore, it is possible to secure a sufficient amount of refrigerating machine oil in the compressor (30).

    Further, since the kinematic viscosity of the refrigerating machine oil is 30 cSt or more at 40 ° C., the kinematic viscosity is not too low and the oil film strength is not insufficient, and the lubricating performance is ensured. Moreover, since the surface tension of the refrigerating machine oil is 0.02 N / m or more at 20 ° C., the refrigerating machine oil does not easily form small oil droplets in the gas refrigerant in the compressor (30), and a large amount from the compressor (30). Refrigerator oil is not discharged. For this reason, the amount of refrigerating machine oil stored in the compressor (30) can be further ensured.

    Further, since the saturated moisture content of the refrigerating machine oil is 2000 ppm or more at a temperature of 30 ° C./90% relative humidity, the refrigerating machine oil has a relatively high hygroscopicity. Thereby, it becomes possible to capture the water in HFO-1234yf to a certain extent by the refrigerating machine oil. HFO-1234yf has a molecular structure that is easily altered / deteriorated due to the influence of contained moisture. However, such deterioration can be suppressed by the hygroscopic effect of the refrigerating machine oil.

    Chlorine and sulfur may adversely affect the stability of the refrigerant. Therefore, since the concentration of chlorine and sulfur in the refrigerating machine oil is suppressed to 50 ppm or less, the amount of the refrigerant that is decomposed in the refrigerant circuit is reduced, and the resin resulting from the substance generated by the decomposition of the refrigerant Deterioration of functional parts made is suppressed.

    In addition, an acid scavenger, an extreme pressure additive, an antioxidant, an antifoaming agent, an oily agent, and a copper deactivator are added as additives to the refrigerating machine oil of this embodiment. In the present embodiment, all the six additives are used, but each additive may be added as necessary, and only one additive may be used. The blending amount of each additive is set so that the ratio contained in the refrigerating machine oil is 0.01% by mass or more and 5% by mass or less. In addition, the compounding amount of the acid scavenger and the compounding amount of the antioxidant are preferably in the range of 0.05% by mass to 3% by mass.

    As the acid scavenger, epoxy compounds such as phenyl glycidyl ether, alkyl glycidyl ether, alkylene glycol glycidyl ether, cyclohexene oxide, α-olefin oxide, and epoxidized soybean oil can be used. Among these, preferred acid scavengers from the viewpoint of compatibility are phenyl glycidyl ether, alkyl glycidyl ether, alkylene glycol glycidyl ether, cyclohexene oxide, and α-olefin oxide. The alkyl group of the alkyl glycidyl ether and the alkylene group of the alkylene glycol glycidyl ether may have a branch. These carbon numbers should just be 3 or more and 30 or less, more preferably 4 or more and 24 or less, and still more preferably 6 or more and 16 or less. The α-olefin oxide may have a total carbon number of 4 or more and 50 or less, more preferably 4 or more and 24 or less, and even more preferably 6 or more and 16 or less. Only one type of acid scavenger may be used, or a plurality of types may be used in combination.

    In addition, what contains phosphate ester can be used for an extreme pressure additive. Examples of phosphoric acid esters that can be used include phosphoric acid esters, phosphorous acid esters, acidic phosphoric acid esters, and acidic phosphorous acid esters. Moreover, what contains the amine salt of phosphoric acid ester, phosphorous acid ester, acidic phosphoric acid ester, and acidic phosphorous acid ester can also be used for an extreme pressure additive.

    Phosphate esters include triaryl phosphates, trialkyl phosphates, trialkylaryl phosphates, triarylalkyl phosphates, trialkenyl phosphates, and the like. Further, phosphoric acid esters are specifically listed as triphenyl phosphate, tricresyl phosphate, benzyl diphenyl phosphate, ethyl diphenyl phosphate, tributyl phosphate, ethyl dibutyl phosphate, cresyl diphenyl phosphate, dicresyl phenyl phosphate, ethyl phenyl diphenyl phosphate. , Diethylphenylphenyl phosphate, propylphenyldiphenyl phosphate, dipropylphenylphenyl phosphate, triethylphenyl phosphate, tripropylphenyl phosphate, butylphenyl diphenyl phosphate, dibutylphenylphenyl phosphate, tributylphenyl phosphate, trihexyl phosphate, tri (2-ethylhexyl) Hosphee There tridecyl phosphate, trilauryl phosphate, trimyristyl phosphate, tri palmityl phosphate, tristearyl phosphate, and trioleyl phosphate and the like.

    Specific examples of phosphites include triethyl phosphite, tributyl phosphite, triphenyl phosphite, tricresyl phosphite, tri (nonylphenyl) phosphite, tri (2-ethylhexyl) phosphite, tridecyl. There are phosphites, trilauryl phosphites, triisooctyl phosphites, diphenylisodecyl phosphites, tristearyl phosphites, trioleyl phosphites and the like.

    Specific examples of the acidic phosphate ester include 2-ethylhexyl acid phosphate, ethyl acid phosphate, butyl acid phosphate, oleyl acid phosphate, tetracosyl acid phosphate, isodecyl acid phosphate, lauryl acid phosphate, tridecyl acid phosphate, Examples include stearyl acid phosphate and isostearyl acid phosphate.

    Specific examples of the acidic phosphite include dibutyl hydrogen phosphite, dilauryl hydrogen phosphite, dioleyl hydrogen phosphite, distearyl hydrogen phosphite, diphenyl hydrogen phosphite and the like. Among the above phosphoric acid esters, oleyl acid phosphate and stearyl acid phosphate are preferred.

    Specific examples of mono-substituted amines among the amines used in the amine salts of phosphoric acid ester, phosphorous acid ester, acidic phosphoric acid ester or acidic phosphorous acid ester include butylamine, pentylamine, hexylamine, cyclohexylamine, There are octylamine, laurylamine, stearylamine, oleylamine, benzylamine and the like. Specific examples of disubstituted amines include dibutylamine, dipentylamine, dihexylamine, dicyclohexylamine, dioctylamine, dilaurylamine, distearylamine, dioleylamine, dibenzylamine, stearyl monoethanolamine, decyl monoethanol. Examples include ethanolamine, hexyl monopropanolamine, benzyl monoethanolamine, phenyl monoethanolamine, and tolyl monopropanol. Specific examples of the tri-substituted amine include tributylamine, tripentylamine, trihexylamine, tricyclohexylamine, trioctylamine, trilaurylamine, tristearylamine, trioleylamine, tribenzylamine, dioleyl monoethanolamine, Dilauryl monopropanolamine, dioctyl monoethanolamine, dihexyl monopropanolamine, dibutyl monopropanolamine, oleyl diethanolamine, stearyl dipropanolamine, lauryl diethanolamine, octyl dipropanolamine, butyl diethanolamine, benzyl Diethanolamine, phenyl diethanolamine, tolyl dipropanolamine, xylyl diethanolamine Emissions, triethanolamine, there is a tri-propanolamine and the like.

    It is also possible to add extreme pressure additives other than those described above. For example, extreme pressure additives of organic sulfur compounds such as monosulfides, polysulfides, sulfoxides, sulfones, thiosulfinates, sulfurized fats and oils, thiocarbonates, thiophenes, thiazoles, methanesulfonate esters, etc. , Thiophosphate ester extreme pressure additives such as thiophosphate triesters, ester extreme pressure additives such as higher fatty acids, hydroxyaryl fatty acids, polyhydric alcohol esters, acrylate esters, chlorinated hydrocarbons Organic chlorinated extreme pressure additives such as chlorinated carboxylic acid derivatives, fluorinated aliphatic carboxylic acids, fluorinated ethylene resins, fluorinated alkylpolysiloxanes, fluorinated graphite, etc. Agents, alcohol-based extreme pressure additives such as higher alcohols, naphthenates (lead naphthenate, etc.), fat Use extreme pressure additives of metal compounds such as salts (fatty acid lead, etc.), thiophosphates (zinc dialkyldithiophosphate, etc.), thiocarbamates, organomolybdenum compounds, organotin compounds, organogermanium compounds, borate esters, etc. It is possible.

    As the antioxidant, a phenol-based antioxidant or an amine-based antioxidant can be used. The phenolic antioxidants include 2,6-di-tert-butyl-4-methylphenol (DBPC), 2,6-di-tert-butyl-4-ethylphenol, 2,2′-methylenebis (4 -Methyl-6-tert-butylphenol), 2,4-dimethyl-6-tert-butylphenol, 2,6-di-tert-butylphenol and the like. Amine antioxidants include N, N'-diisopropyl-p-phenylenediamine, N, N'-di-sec-butyl-p-phenylenediamine, phenyl-α-naphthylamine, N.N. N'-di-phenyl-p-phenylenediamine and the like. An oxygen scavenger that traps oxygen can also be used as the antioxidant.

    Moreover, as a copper deactivator, benzotriazole, its derivative, etc. can be used. As the antifoaming agent, a silicon compound can be used. As the oily agent, higher alcohols can be used.

    In addition, the refrigerating machine oil of the present embodiment includes a load bearing additive, an oxygen scavenger, a chlorine scavenger, a cleaning dispersant, a viscosity index improver, a rust inhibitor, a stabilizer, a corrosion inhibitor, and a flow as necessary. It is also possible to add a point depressant or the like. An oxygen scavenger is an additive that scavenges oxygen. The blending amount of each additive may be 0.01 mass% or more and 5 mass% or less, and preferably 0.05 mass% or more and 3 mass% or less.

-Driving action-
The operation of the air conditioner (20) will be described. The air conditioner (20) can perform a cooling operation and a heating operation, and switching between the cooling operation and the heating operation is performed by the four-way switching valve (13).

<Cooling operation>
During the cooling operation, the four-way selector valve (13) is set to the first state. When the compressor (30) is operated in this state, the high-pressure refrigerant discharged from the compressor (30) releases heat to the outdoor air and condenses in the outdoor heat exchanger (11). The refrigerant condensed in the outdoor heat exchanger (11) is distributed to each indoor circuit (17a, 17b, 17c). In each indoor circuit (17a, 17b, 17c), the refrigerant flowing in is depressurized by the indoor expansion valve (16a, 16b, 16c) and then absorbs heat from the indoor air in the indoor heat exchanger (15a, 15b, 15c). Evaporate. On the other hand, the room air is cooled and supplied to the room.

    The refrigerant evaporated in each indoor circuit (17a, 17b, 17c) merges with the refrigerant evaporated in the other indoor circuits (17a, 17b, 17c) and returns to the outdoor circuit (9). In the outdoor circuit (9), the refrigerant returned from the indoor circuits (17a, 17b, 17c) is compressed again by the compressor (30) and discharged. During cooling operation, the opening degree of each indoor expansion valve (16a, 16b, 16c) is set so that the superheat degree of the refrigerant at the outlet of the indoor heat exchanger (15a, 15b, 15c) is a constant value (for example, 5 ° C). The superheat degree is controlled so as to be.

<Heating operation>
During the heating operation, the four-way selector valve (13) is set to the second state. When the compressor (30) is operated in this state, the high-pressure refrigerant discharged from the compressor (30) is distributed to the indoor circuits (17a, 17b, 17c). In each indoor circuit (17a, 17b, 17c), the refrigerant that has flowed into the indoor heat exchanger (15a, 15b, 15c) dissipates heat to the indoor air and condenses. On the other hand, room air is heated and supplied indoors. The refrigerant condensed in the indoor heat exchanger (15a, 15b, 15c) merges with the refrigerant that has passed through the other indoor circuits (17a, 17b, 17c), and returns to the outdoor circuit (9).

    In the outdoor circuit (9), the refrigerant returned from the indoor circuits (17a, 17b, 17c) is depressurized by the outdoor expansion valve (12), and then absorbs heat from the outdoor air in the outdoor heat exchanger (11). Evaporate. The refrigerant evaporated in the outdoor heat exchanger (11) is compressed again by the compressor (30) and discharged. During the heating operation, the opening degree of each indoor expansion valve (16a, 16b, 16c) is constant, and the degree of supercooling of the refrigerant at the outlet of the indoor heat exchanger (15a, 15b, 15c) is a constant value (for example, 5 ° C). The sub-cool is controlled to be.

-Effect of the embodiment-
In this embodiment, refrigeration oil having an aniline point of −100 ° C. or more and 0 ° C. or less is used for the compressor (30). Thereby, it can suppress that the insulating material of each bearing (41,42,43,44) and electric motor (85) which are resin functional parts swells / shrinks with refrigerating machine oil. Therefore, the denaturation / deterioration of the resin functional parts due to the refrigerating machine oil can be suppressed. That is, in each bearing (41, 42, 43, 44), it is possible to suppress a decrease in sliding performance, and it is possible to suppress a decrease in insulation in the insulating material of the electric motor (85). As a result, the durability of the resin functional parts is improved, and the reliability of the compressor (30) or the refrigeration apparatus is improved.

In the present embodiment, the refrigerant of the refrigerant circuit (10) has a molecular formula: C ₃ H _m F _n (where m and n are integers of 1 to 5 and the relationship of m + n = 6 is established). The refrigerant (that is, HFO-1234yf) composed of the refrigerant represented by the molecular structure and having one double bond is used. This HFO-1234yf has a relatively unstable molecular structure because it has a double bond and the like, and the refrigerant is likely to deteriorate and impurities and the like are easily generated. Then, the bearings (41, 42, 43, 44), which are resin functional parts, may be chemically / physically modified and deteriorated by the generated impurities or the like. However, in this embodiment, each bearing (41, 42, 43, 44) is made of any one of polytetrafluoroethylene, polyphenylene sulfide, and polyamide resin. These resin materials have a relatively high stability against impurities generated from the refrigerant. Therefore, it is possible to avoid deterioration of the bearing (41, 42, 43, 44) due to the influence of the above impurities, and the bearing (41, 42, 43, 44) can obtain a desired sliding performance. it can.

    In the present embodiment, since the refrigeration oil having a saturated water content of 2000 ppm or more at a temperature of 30 ° C. and a relative humidity of 90% is used, the water in the refrigerant can be captured by the refrigeration oil. For this reason, it can prevent that HFO-1234yf deteriorates by the influence of a water | moisture content.

    Moreover, in this embodiment, the refrigerating machine oil which has at least 1 as a main component among polyalkylene glycol, polyol ester, and polyvinyl ether was used. Thereby, a refrigerant | coolant and refrigerator oil become easy to melt | dissolve mutually. Therefore, even if the refrigeration oil flows out into the refrigerant circuit (10), the refrigeration oil is dissolved in the refrigerant and easily returned to the compressor (30). As a result, oil rising in the compressor (30) can be suppressed, and a shortage of refrigerating machine oil in the compressor (30) and further poor lubrication can be avoided. Therefore, the reliability of the compressor (30) can be improved.

    In the present embodiment, since the kinematic viscosity of the refrigerating machine oil is set to 30 cSt or more and 400 cSt or less at 40 ° C., sufficient lubrication performance of the sliding portion can be ensured. Furthermore, since the pour point of the refrigerating machine oil is set to −30 ° C. or lower, the flowability of the refrigerating machine oil can be ensured even at a relatively low temperature portion in the refrigerant circuit (10). As a result, the supply amount of the refrigerating machine oil and the oil film strength can be sufficiently ensured in the sliding portion of the compressor (30). As a result, the lubricating performance in the compressor (30) is further improved.

    Moreover, in this embodiment, since the surface tension of the refrigerating machine oil is 0.02 N / m or more and 0.04 N / m or less at 20 ° C., the size of the refrigerating machine oil droplets can be optimized. As a result, it is possible to prevent the refrigerating machine oil from being discharged in a large amount from the refrigerating machine oil compressor (30) and the refrigerating machine oil discharged from the compressor (30) from being difficult to return to the compressor (30). it can. As a result, oil rise can be suppressed in the compressor (30), and poor lubrication can be prevented.

    In this embodiment, since the chlorine concentration and sulfur concentration of the refrigerating machine oil are 50 ppm or less, deterioration of the refrigerant due to chlorine and sulfur can be suppressed. As a result, the generation of impurities due to the deterioration of the refrigerant can be suppressed, so that the denaturation / deterioration of the insulating material of each bearing (41, 42, 43, 44) and motor (85), which are resin functional parts, is effectively suppressed. can do.

    Moreover, in this embodiment, six additives of an acid scavenger, an extreme pressure additive, an antioxidant, an antifoaming agent, an oiliness agent, and a copper deactivator are ensured so as to ensure the lubricating performance of the refrigerating machine oil. Of these, at least one additive is added to the refrigerating machine oil. For this reason, since it can suppress that the lubrication performance of refrigerating machine oil falls, it can suppress that lubrication failure arises in a compressor (30).

    In the present embodiment, a mixed refrigerant of HFO-1234yf and difluoromethane, which is a high-pressure refrigerant, can also be used as the refrigerant in the refrigerant circuit (10). In that case, the influence which the pressure loss of a refrigerant | coolant has on the operating efficiency of an air conditioning apparatus (20) can be made small. Therefore, the actual operating efficiency of the air conditioner (20) can be improved.

    In the present embodiment, a mixed refrigerant of HFO-1234yf and pentafluoroethane, which is a flame-retardant refrigerant, can also be used as the refrigerant in the refrigerant circuit (10). In that case, the combustibility of the refrigerant filled in the refrigerant circuit (10) can be sufficiently reduced, and the reliability of the air conditioner (20) can be improved.

-Modification 1 of embodiment-
The refrigerating machine oil used in the compressor (30) of the present embodiment may be a refrigerating machine oil mainly composed of a polyol ester among the three types of base oils of polyalkylene glycol, polyol ester and polyvinyl ether. Polyol esters include “esters of aliphatic polyhydric alcohols with linear or branched fatty acids”, “partial esters of aliphatic polyhydric alcohols with linear or branched fatty acids” and “fats” Any one of "complex ester of partial ester of aliphatic polyhydric alcohol and linear or branched fatty acid having 3 to 9 carbon atoms and aliphatic dibasic acid or aromatic dibasic acid" It is used. Among these polyol esters, these polyol esters are excellent in compatibility with a refrigerant represented by the above molecular formula and having one double bond in the molecular structure.

    Aliphatic polyhydric alcohols that form “esters or partial esters of aliphatic polyhydric alcohols with linear or branched fatty acids” include ethylene glycol, propylene glycol, butylene glycol, neopentyl glycol, trimethylol ethane Ditrimethylolethane, trimethylolpropane, ditrimethylolpropane, glycerin, pentaerythritol, dipentaerythritol, tripentaerythritol, sorbitol, and the like can be used. Among these, as the aliphatic polyhydric alcohol, pentaerythritol, dipentaerythritol and tripentaerythritol are preferable.

    In addition, fatty acids having 3 to 12 carbon atoms can be used, for example, propionic acid, butyric acid, pivalic acid, valeric acid, caproic acid, heptanoic acid, octanoic acid, nonanoic acid, decanoic acid, dodecanoic acid. , Isovaleric acid, neopentanoic acid, 2-methylbutyric acid, 2-ethylbutyric acid, 2-methylhexanoic acid, 2-ethylhexanoic acid, isooctanoic acid, isononanoic acid, isodecanoic acid, 2,2-dimethyloctanoic acid, 2-butyl Octanoic acid and 3,5,5-trimethylhexanoic acid can be used. As the fatty acid, a fatty acid having 5 to 12 carbon atoms is preferable, and a fatty acid having 5 to 9 carbon atoms is more preferable. Specifically, valeric acid, hexanoic acid, heptanoic acid, 2-methylhexanoic acid, 2-ethylhexanoic acid, isooctanoic acid, isononanoic acid, isodecanoic acid, 2,2-dimethyloctanoic acid, 2-butyloctanoic acid, 3 5,5-trimethylhexanoic acid and the like are preferable.

    In addition, “a complex ester of a partial ester of an aliphatic polyhydric alcohol and a linear or branched fatty acid having 3 to 9 carbon atoms and an aliphatic dibasic acid or aromatic dibasic acid” Fatty acids having 5 to 7 carbon atoms are preferred, and fatty acids having 5 or 6 carbon atoms are more preferred. Specifically, valeric acid, hexanoic acid, isovaleric acid, 2-methylbutyric acid, 2-ethylbutyric acid or a mixture thereof is preferable. Further, a fatty acid in which a fatty acid having 5 carbon atoms and a fatty acid having 6 carbon atoms are mixed in a weight ratio of 10:90 or more and 90:10 or less can be used.

    Examples of the aliphatic dibasic acid include succinic acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, undecanedioic acid, dodecanedioic acid, tridecanedioic acid, and docosannadioic acid. Aromatic dibasic acids include phthalic acid and isophthalic acid. In the esterification reaction for preparing the complex ester, a polyhydric alcohol and a dibasic acid are reacted at a predetermined ratio to be partially esterified, and then the partial ester is reacted with a fatty acid. The reaction order of the dibasic acid and the fatty acid may be reversed, or the dibasic acid and the fatty acid may be mixed and used for esterification.

-Modification 2 of embodiment-
The refrigerating machine oil used in the compressor (30) of the present embodiment may be a refrigerating machine oil mainly composed of polyalkylene glycol among the three types of base oils of polyalkylene glycol, polyol ester and polyvinyl ether.

In this modified example 2, the molecular formula: R 1 (R 2) _m (R 3 O) _n R 4 (where m and n are integers, R 1 and R 4 are hydrogen, an alkyl group having 1 to 6 carbon atoms, or an aryl group. R2 and R3 each represents an alkyl group having 1 to 4 carbon atoms.) Polyalkylene glycol having a molecular structure represented by the following formula is used. Among the polyalkylene glycols, the polyalkylene glycol having this molecular structure is excellent in compatibility with a refrigerant represented by the above molecular formula and having one double bond in the molecular structure.

—Modification 3 of Embodiment—
In the present invention, other than the insulating materials of the bearings (41, 42, 43, 44) and the electric motor (85) described above can be used as resin functional parts.

    For example, on the surface of the sliding part such as the movable scroll (76), fixed scroll (75), Oldham ring (79), etc., a sliding made of fluorine resin such as polytetrafluoroethylene, polyphenylene sulfide or polyamide resin. A member may be formed. Further, a sliding member made of any one of a fluorine-based resin such as polytetrafluoroethylene, polyphenylene sulfide, and polyamide resin may be applied to the sliding portion of the valve body of the four-way switching valve (13). In particular, 66 nylon is preferably used as the polyamide resin in the sliding portion of the valve body.

    In the present invention, a seal member for preventing leakage of the refrigerant can also be applied as a resin functional part. For example, in FIG. 4, a seal ring (47) as a seal member is interposed between the movable side end plate (76b) of the movable scroll (76) and the upper surface of the housing (77). The seal ring (47) partitions the upper space of the housing (77) into the inside and outside. That is, the seal ring (47) prevents the high-pressure refrigerant on the inner peripheral side from leaking to the outer peripheral side, that is, the suction side of the compression chamber (30). The seal ring (47) is preferably composed of any one of polytetrafluoroethylene, polyphenylene sulfide, chloroprene rubber, silicon rubber, hydrogenated nitrile rubber, fluorine rubber, and hydrin rubber. These resin materials have relatively high stability against impurities generated due to deterioration of the refrigerant. As a result, it is possible to suppress the deterioration of the seal ring (47) accompanying the generation of the impurities.

    The seal member to which the present invention is applied is, for example, an O-ring interposed between the inner peripheral surface of the casing (70) and the outer peripheral surface of the housing (77), a suction pipe (56), or a discharge pipe. The packing etc. which are interposed in the pipe joint part of (57) are also mentioned.

<< Other Embodiments >>
The above embodiment may be configured as follows.

    For example, in the said embodiment, you may use the refrigerating machine oil which has 2 or more of polyalkylene glycol, polyol ester, and polyvinyl ether as a main component.

In the above embodiment, as the refrigerant of the refrigerant circuit (10), the molecular _formula: C ₃ H m _{F n} (where, m and n is 1 to 5 integer relationship m + n = 6 is satisfied.) A refrigerant having a single composition consisting only of a refrigerant other than HFO-1234yf may be used among the refrigerants represented by the formula (1) and having one double bond in the molecular structure. Specifically, 1,3,3,3-tetrafluoro-1-propene (referred to as “HFO-1234ze”, the chemical formula is represented by CF ₃ —CH═CHF), 1,2,3,3. -Tetrafluoro-1-propene (referred to as “HFO-1234ye”, chemical formula is represented by CHF ₃ —CF═CHF), 3,3,3-trifluoro-1-propene (“HFO-1243zf”) good chemical formula. represented by _{CF 3 -CH = CH 2),} 1,2,2- trifluoro-1-propene (a chemical formula thereof is represented by _{CH 3 -CF = CF 2.)} , 2- fluoro - propene (. a chemical formula thereof is represented by _CH 3 -CF = _{CH 2)} or the like can be used.

Moreover, in the said embodiment, as a refrigerant | coolant of a refrigerant circuit (10), the refrigerant | coolant (2,3,3,3-tetrafluoro-1-propene, which is represented by the said molecular formula and has one double bond in molecular structure, 1,3,3,3-tetrafluoro-1-propene, 1,2,3,3-tetrafluoro-1-propene, 3,3,3-trifluoro-1-propene, 1,2,2-tri (Fluoro-1-propene, 2-fluoro-propene) may be used as a mixed refrigerant in which subcomponents composed of other substances are mixed. As an auxiliary component constituting this mixed refrigerant, for example, 1,2,3,3,3-pentafluoro-1-propene (referred to as “HFO-1225ye”, the chemical formula is represented by CF ₃ —CF═CHF. ), 1,3,3,3-tetrafluoro-1-propene (referred to as “HFO-1234ze”, the chemical formula is represented by CF ₃ —CH═CHF), 1,2,3,3-tetra Fluoro-1-propene (referred to as “HFO-1234ye”, the chemical formula is represented by CHF ₂ —CF═CHF), 3,3,3-trifluoro-1-propene (referred to as “HFO-1243zf”), chemical formula is _CF 3. represented by -CH = CH _2), 1,2,2- trifluoro-1-propene (a chemical formula thereof is represented by _{CH 3 -CF = CF 2.)} , 2- fluoro -1 -Propene (chemical formula is CH _3- CF = CH ₂ )) or the like.

    In the above embodiment, the refrigerant represented by the above molecular formula and having one double bond in the molecular structure (2,3,3,3-tetrafluoro-1-propene, 1,3,3,3-tetra Fluoro-1-propene, 1,2,3,3-tetrafluoro-1-propene, 3,3,3-trifluoro-1-propene, 1,2,2-trifluoro-1-propene, 2-fluoro -1-propene), HFC-32 (difluoromethane), HFC-125 (pentafluoroethane), HFC-134 (1,1,2,2-tetrafluoroethane), HFC-134a (1,1,1). , 2-tetrafluoroethane), HFC-143a (1,1,1-trifluoroethane), HFC-152a (1,1-difluoroethane), HFC-161, HFC-227ea, HFC-2 6ea, HFC-236fa, HFC-365mfc, methane, ethane, propane, propene, butane, isobutane, pentane, 2-methylbutane, cyclopentane, dimethyl ether, bis-trifluoromethyl-sulfide, carbon dioxide, helium You may use the mixed refrigerant which added.

    For example, a mixed refrigerant composed of two components of HFO-1234yf and HFC-32 may be used. For example, a mixed refrigerant composed of 78.2% by mass of HFO-1234yf and 21.8% by mass of HFC-32 can be used. The mixed refrigerant of HFO-1234yf and HFC-32 may have a ratio of HFO-1234yf of 70% by mass to 94% by mass and a ratio of HFC-32 of 6% by mass to 30% by mass, preferably The ratio of HFO-1234yf may be 77% by mass or more and 87% by mass or less and the ratio of HFC-32 may be 13% by mass or more and 23% by mass or less, and more preferably the ratio of HFO-1234yf is 77% by mass or more and 79% by mass. It is preferable that the ratio of HFC-32 is 21% by mass or more and 23% by mass or less at a mass% or less.

    Further, a mixed refrigerant of HFO-1234yf and HFC-125 may be used. In this mixed refrigerant, the ratio of HFC-125 is preferably 10% by mass or more, more preferably 10% by mass or more and 20% by mass or less.

    Moreover, you may use the mixed refrigerant | coolant which consists of 3 components of HFO-1234yf, HFC-32, and HFC-125. In this case, a mixed refrigerant composed of 52% by mass of HFO-1234yf, 23% by mass of HFC-32, and 25% by mass of HFC-125 can be used.

    Moreover, about the said embodiment, you may provide the dryer with which the silicic acid and the synthetic zeolite were filled as a desiccant in a refrigerant circuit (10).

    Moreover, in the said embodiment, the compressor (30) may be comprised by what is called a horizontal type. Furthermore, about the said embodiment, the compressor (30) may be other types of compressors, such as a reciprocating type, a rotary type, and a screw type.

    Moreover, in the said embodiment, although the air conditioning apparatus (20) which selectively performs air_conditionaing | cooling operation and heating operation is comprised by the freezing apparatus, the use of a freezing apparatus is not limited to this. That is, the refrigeration apparatus of the present invention may constitute an air conditioning apparatus dedicated to heating, may constitute a cooling apparatus that cools the interior of a refrigerator or a freezer, or may depend on a refrigerant. You may comprise the hot-water supply apparatus which heats water.

    As described above, the present invention is useful for a refrigeration apparatus that performs a refrigeration cycle.

10 Refrigerant circuit
20 Air conditioning equipment (refrigeration equipment)
30 Compressor
41 Upper bearing (sliding member, resin functional parts)
42 Intermediate bearings (sliding members, resin functional parts)
43 Lower bearing (sliding member, resin functional part)
44 Thrust bearings (sliding members, resin functional parts)
47 Seal ring (seal member, resin functional parts)
82 Compression mechanism (fluid machine)
85 Electric motor

Claims (15)

Refrigerant circuit (10) that performs a refrigeration cycle by circulating a refrigerant by a compressor (30) in which predetermined functional parts made of resin (41, 42, 43, 44, 47) are arranged to come into contact with the refrigerant and refrigeration oil With
The refrigerant of the refrigerant circuit (10) is represented by the molecular formula: C ₃ H _m F _n (where m and n are integers of 1 to 5, and the relationship m + n = 6 is established) and in the molecular structure In which a refrigerant having one double bond or a mixed refrigerant containing the refrigerant is used,
The refrigerating machine characterized in that the refrigerating machine oil of the compressor (30) has an aniline point of -100 ° C or higher and 0 ° C or lower. In claim 1,
The resin functional component is composed of sliding members (41, 42, 43, 44) provided at predetermined sliding portions of the compressor (30),
The refrigeration apparatus, wherein the sliding member (41, 42, 43, 44) is made of polytetrafluoroethylene, polyphenylene sulfide, or polyamide resin. In claim 1,
The resin functional component is composed of a seal member (47) for preventing leakage of refrigerant in a predetermined gap in the compressor (30),
The refrigeration apparatus, wherein the sealing member (47) is made of any one of polytetrafluoroethylene, polyphenylene sulfide, chloroprene rubber, silicon rubber, hydrogenated nitrile rubber, fluorine rubber, and hydrin rubber. In claim 1,
The compressor (30) includes a fluid machine (82) that compresses a refrigerant, and an electric motor (85) that has an insulating material made of resin and drives the fluid machine (82).
The refrigeration apparatus, wherein the resin functional component is made of an insulating material of the electric motor (85). In any one of Claims 1 thru | or 4,
The refrigerating machine has a saturated water content of 2000 ppm or more at a temperature of 30 ° C. and a relative humidity of 90%. In claim 5,
The refrigerating machine oil is characterized in that the main component is at least one of polyalkylene glycol, polyol ester and polyvinyl ether. In claim 5 or 6,
The refrigerating machine oil has a kinematic viscosity of 30 cSt or more and 400 cSt or less at 40 ° C. and a pour point of −30 ° C. or less. In any one of Claims 5 thru | or 7,
The refrigerating machine has a surface tension of 0.02 N / m or more and 0.04 N / m or less at 20 ° C. In any one of Claims 5 thru | or 8,
The refrigerating machine oil is characterized in that the chlorine concentration is 50 ppm or less. In any one of Claims 5 thru | or 9,
The refrigerating machine, wherein the refrigerating machine oil has a sulfur concentration of 50 ppm or less. In any one of Claims 5 thru | or 10,
The refrigerating machine oil includes at least one additive selected from an acid scavenger, an extreme pressure additive, an antioxidant, an oxygen scavenger, an antifoaming agent, an oil agent, and a copper deactivator. Refrigeration equipment characterized. In claim 11,
In the above refrigerating machine oil, when one kind of additive is added, the ratio of the additive is 0.01 mass% or more and 5 mass% or less, and when a plurality of kinds of additives are added, A refrigeration apparatus characterized in that the ratio of the additive is 0.01 mass% or more and 5 mass% or less. In any one of Claims 1 thru | or 12,
Refrigerant represented by the above molecular formula: C ₃ H _m F _n (where m and n are integers of 1 to 5 and the relationship m + n = 6 is established) and has one double bond in the molecular structure. Is 2,3,3,3-tetrafluoro-1-propene. In any one of Claims 1 thru | or 13,
The refrigerant of the refrigerant circuit (10) is expressed by the molecular formula: C ₃ H _m F _n (where m and n are integers of 1 to 5, and the relationship of m + n = 6 is established) and has a molecular structure. A refrigeration apparatus comprising a mixed refrigerant including a refrigerant having one double bond therein and difluoromethane. In any one of Claims 1 thru | or 13,
The refrigerant of the refrigerant circuit (10) is expressed by the molecular formula: C ₃ H _m F _n (where m and n are integers of 1 to 5, and the relationship of m + n = 6 is established) and has a molecular structure. A refrigeration apparatus comprising a mixed refrigerant containing a refrigerant having one double bond therein and pentafluoroethane.

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