JP5339788B2 - Compressor and refrigeration cycle equipment - Google Patents

Description

  The present invention relates to a refrigeration oil used together with a refrigerant circulating in a refrigeration cycle, a compressor using the same, and a refrigeration cycle apparatus equipped with the compressor, and in particular, a refrigerant having a double bond in a molecular structure. The present invention relates to a refrigeration oil, a compressor, and a refrigeration cycle device used together.

  Conventionally, refrigerants used in refrigeration cycle apparatuses such as air conditioners, refrigeration apparatuses, heat pump systems, etc., do not use refrigerants for refrigeration air conditioners containing chlorine, such as CFC-12 and HCFC22, from the viewpoint of ozone layer protection. Instead of such refrigerants, HFC (hydrofluorocarbon) refrigerants (for example, HFC134a, R410A, R407C, etc.) mainly composed of carbon, hydrogen and fluorine have come to be used. . However, the use of HFC refrigerants with a large global warming potential is being avoided due to further increasing interest in global environmental problems in recent years, and the replacement of HFC refrigerants with refrigerants with a low global warming potential is being investigated. .

  As such, hydrofluoroolefins (also referred to as fluoroalkenes) have become promising candidates for alternative refrigerants (see, for example, Patent Document 1). This hydrofluoroolefin has a characteristic that the global warming potential is small because of its low chemical stability compared to conventional HFC refrigerants. The global warming potential of R410A, one of the HFC refrigerants, is about 2000 times the global warming potential of carbon dioxide, whereas the global warming potential of hydrofluoroolefins is It is about 4 times the global warming potential. Hydrofluoroolefin also has a characteristic that its pressure is comparable to that of the conventional HFC134a refrigerant. The global warming potential is a value indicating the degree of the greenhouse effect based on the greenhouse effect of carbon dioxide.

  In general, a refrigeration cycle apparatus has a refrigeration cycle in which a compressor, a condenser, a throttling device, and an evaporator are sequentially connected by refrigerant piping. The refrigeration cycle apparatus is operated by enclosing and circulating refrigerant and refrigeration oil in the refrigeration cycle. In that case, a metal contact (metal contact) often occurs at the sliding portion inside the compressor. Therefore, it is necessary to supply a sufficient amount of refrigerating machine oil to the sliding portion inside the compressor to reduce the friction coefficient. Otherwise, the sliding portion inside the compressor will be worn and seized, and the compressor will fail.

As an example using such refrigeration oil, “a compressor that is used in a refrigeration cycle and that stores refrigeration oil used as a lubricating oil in an airtight container and compresses at least refrigerant gas, A fatty acid ester oil having a critical temperature of 40 ° C. or higher, a viscosity of 2 to 70 cSt when the viscosity is 40 ° C., 1 to 9 cSt when the viscosity is 100 ° C., and having at least two ester bonds (—O—CO—) in the molecule Has been proposed (see, for example, Patent Document 1). In the technique described in Patent Document 1, a refrigerant mainly composed of HFC has a viscosity of 2 to 70 cSt when the viscosity is 40 ° C., 1 to 9 cSt when the viscosity is 100 ° C., a volume resistivity of 10 ¹³ Ωcm or more, and a molecular A fatty acid ester oil having at least two ester bonds in the structure is used as a base oil, and the amount of water contained in the oil is suppressed to 500 ppm or less.

  In addition, “in the refrigerant compressor using HFC134a as the refrigerant, the oil applied to the components of the compressor or the oil used at the time of assembling the compressor is an oil that is in a two-phase separated state and has no mutual solubility. A refrigerant compressor has been proposed (see, for example, Patent Document 2). In the technique described in Patent Document 2, an alkylbenzene having a viscosity of 200 cSt or less and a specific gravity lighter than that of the refrigerant without having mutual solubility (hereinafter referred to as compatibility) with a refrigerant mainly composed of HFC. Polyalphaolefin is applied to refrigerating machine oil.

Japanese Patent Laid-Open No. 08-253779 (page 10, FIG. 7, etc.) Japanese Patent Laid-Open No. 05-157379 (page 5, FIG. 1, etc.)

  Even if ester oil is applied as a refrigeration oil for a compressor as in the technique described in Patent Document 1, a refrigerant having extremely good chemical stability, that is, a refrigerant having no double bond in the molecular structure. (For example, conventional HFC refrigerants such as HFC134a and R410A (HFC32 / HFC125 = 50% / 50%)) ensure good lubrication performance by suppressing the amount of water in the oil. Was able to. Further, in the technique described in Patent Document 2, since alkylbenzene and polyalphaolefin that are not compatible with HFC refrigerants are applied as refrigerating machine oils, refrigeration such as ester oils that are soluble with HFC refrigerants is used. Refrigerating machine oil having a lower viscosity than when machine oil was applied could be used.

  However, as in the technique described in Patent Document 1, when ester oil is applied to the compressor oil in the compressor, particularly at the start of the refrigeration cycle apparatus under conditions where the outside air temperature is low, such as in winter, When a large amount of liquid refrigerant flows into the compressor, the ester oil will cause a decrease in viscosity. If it does so, an oil film cannot be formed in the bearing part (for example, an upper bearing, a lower bearing, etc.) inside a compressor, and it will become easy to generate | occur | produce seizure, and the sliding part (for example, the outer periphery of a rolling piston) There is a problem that the amount of wear tends to increase at the contact portion between the surface and the tip of the vane, and the compressor is likely to break down.

  Further, as in the technique described in Patent Document 2, when alkylbenzene or polyalphaolefin, which is not compatible with HFC refrigerant, is applied to a compressor as a refrigerating machine oil, a large amount of liquid refrigerant exists inside the compressor. If the refrigeration cycle device is started under conditions that cause seizure, the sliding bearing will not cause seizure, and even if the amount of wear at the tip of the vane does not become so high as to reduce the performance of the compressor, Due to the low compatibility with machine oil, there was a problem that the refrigeration oil that flowed out to the refrigeration cycle was difficult to return to the compressor. That is, the problem of compatibility between the refrigerant and the refrigerating machine oil must be considered.

  Furthermore, in a compressor to which a refrigerant such as 2, 3, 3, 3-tetrafluoropropene, which is one of hydrofluoroolefins (HFO) having a double bond in the molecular structure, is chemically stable. Problems that were not necessary when applying the existing refrigerant must be considered. That is, since 2,3,3,3-tetrafluoropropene has a chemical property that it is decomposed by frictional heat of the sliding portion inside the compressor, if this point is not taken into consideration, the compressor Even if they do not fail, the performance of the refrigeration cycle apparatus will be reduced.

  The present invention has been made in order to solve the above-described problem, and a refrigerant having a double bond in a molecular structure, for example, 2, 3, 3, 3-tetrafluoropropene is used as a refrigerant. Equipped with a refrigerating machine oil that has been chemically stabilized by adding an oily agent to the refrigerating machine oil that is circulated together, a compressor whose reliability has been improved by applying this refrigerating machine oil, and this compressor An object of the present invention is to provide a refrigeration cycle apparatus.

The compressor according to the present invention includes a refrigerant having a double bond in a molecular structure , a refrigerating machine oil that is used together with the refrigerant and has an oily agent, and a compression mechanism unit that compresses the refrigerant. It is a hydrofluoroolefin, and the oily agent is an alcohol having a monovalent OH group having a higher polarity than the hydrofluoroolefin and having 10 to 25 carbon atoms in the molecular structure, and the refrigerating machine oil is The main component is alkylbenzene having a kinematic viscosity of 32 cSt or less at 40 ° C. Furthermore, a refrigeration cycle apparatus according to the present invention is equipped with the above-described compressor.

  According to the refrigerating machine oil according to the present invention, it is used together with a refrigerant having a double bond in the molecular structure, and is constituted by adding an oily agent having a higher polarity than this refrigerant. It can be adsorbed to the metal material as soon as possible, and direct contact between the metal materials can be prevented. Accordingly, it is possible to reduce the friction coefficient in the portion where the oily agent is adsorbed, and to prevent the generation of frictional heat. That is, the generation of frictional heat can be prevented, so that the decomposition of the refrigerant can be suppressed and the refrigerant capacity can be maintained for a long period of time.

  Further, according to the compressor according to the present invention, since the above refrigerating machine oil is used, it is possible to prevent the generation of frictional heat, particularly in the sliding portion inside the compressor, and to decompose the refrigerant inside the compressor. The refrigerant capacity can be maintained for a long time.

  Furthermore, according to the refrigeration cycle apparatus according to the present invention, since the above-described compressor is mounted, the refrigerant is not decomposed by frictional heat generated inside the compressor, and the refrigerant capacity is maintained for a long period of time. It is possible to reduce the performance degradation of the refrigeration cycle apparatus.

  Further, according to the refrigeration cycle apparatus according to the present invention, since the lubricating oil composition is circulated, the chemical properties of the refrigerant are stabilized, sludge generated in the refrigeration cycle can be reduced, and reliability is improved. Can be achieved.

Embodiments of the present invention will be described below.
Embodiment 1 FIG.
In Embodiment 1 of the present invention, the chemical properties of a refrigerant having a double bond, such as 2,3,3,3-tetrafluoropropene (HFO-1234yf), which is one kind of hydrofluoroolefin (HFO), are used. The stabilization of the chemical properties will be described. The structural formula of 2,3,3,3-tetrafluoropropene is represented by CF ₃ CF═CH ₂ and has a double bond in the molecular structure. In other words, 2,3,3,3-tetrafluoropropene has a double bond in its molecular structure, so when applied to, for example, a rotary compressor, it decomposes by frictional heat at a sliding portion where an oil film is difficult to form. Easy to be.

Therefore, in the first embodiment, alcohol having higher polarity than the refrigerant and excellent in adsorptivity is added to the refrigerating machine oil as an oily agent. Excellent adsorbability means that metal contacts are likely to occur. For example, in places such as sliding parts inside the compressor, the oil agent adsorbs to the metal surface faster than the refrigerant adsorbs to the metal surface. Is that you can. The alcohol preferably has 10 to 25 carbon atoms in its molecular structure, and has a linear structure and a monovalent OH group. A typical molecular structure of alcohol is represented by [CH ₃ — (CH ₂ ) n ₁ —OH].

  Therefore, by adding such alcohol as an oleaginous agent to refrigeration machine oil, this oleaginous agent adheres, for example, to the sliding part of a rotary compressor faster than the refrigerant adheres. It is possible to prevent direct contact between the metal materials at the chained portion. Moreover, since a metal contact can be prevented, a friction coefficient can be reduced. That is, since generation | occurrence | production of frictional heat can be suppressed, decomposition | disassembly of the refrigerant | coolant by frictional heat can be prevented effectively, and the chemical property of a refrigerant | coolant can be stabilized.

When the number of carbon atoms in the molecular structure of the alcohol is 10 or less, the linear portion is shortened, so that the effect as an oily agent cannot be sufficiently obtained. Further, if the number of carbon atoms in the molecular structure of the alcohol is 26 or more, there is a concern that the alcohol is solidified. Therefore, the number of carbon atoms constituting the alcohol is preferably 10-25. Further, branching is made at the ends such as [(CH ₃ ) ₂ —CH— (CH ₂ ) n ₂ —OH] and [(CH ₃ CH ₂ ) ₂ —CH— (CH ₂ ) n ₃ —OH]. Almost the same effect can be obtained even if the alcohol has a partial branch such as [CH ₃ — (CH ₂ ) n ₄ —CHCH ₃ — (CH ₂ ) n ₅ —OH]. be able to. Note that n ₁ to n ₅ are determined so that the total number of carbon atoms is 10 to 25 in each molecular structure.

It is desirable to apply alkylbenzene as the main component of refrigerating machine oil. This is because the volume low efficiency of alkylbenzene is 10 ¹⁵ to 10 ¹⁶ Ωcm, so that electrical insulation in the compressor can be ensured. Techniques for applying alkylbenzene to refrigeration oil under HFC refrigerants such as HFC134a and R410A refrigerants have already been put into practical use. The amount of the HFC-based refrigerant dissolved in alkylbenzene is 2% by weight or less. On the other hand, the amount of the refrigerant having a double bond in the molecular structure, such as tetrafluoropropene, dissolved in alkylbenzene is larger than that of the HFC refrigerant.

  Therefore, the oil return property to the compressor is excellent in the refrigerant having a double bond. In other words, the HFC refrigerant has a problem that the compatibility with the alkylbenzene is low and the oil return property to the compressor is poor, but the refrigerant having a double bond has a higher compatibility than the HFC refrigerant and is compressed. The oil return to the machine can be improved. Therefore, it becomes easy to secure refrigerating machine oil inside the compressor, and the effect of suppressing seizure and wear at the sliding portion inside the compressor can be improved. In addition, by applying alkylbenzene, seizure and wear of sliding parts can be prevented even when starting a compressor in winter when liquid refrigerant is stored inside the compressor. A high oil film forming ability can be secured under the operating conditions.

  Alkylbenzene having a kinematic viscosity of 10 to 22 cSt at 40 ° C. under an HFC refrigerant has already been put into practical use. As described above, the amount of the refrigerant having a double bond such as tetrafluoropropene dissolved in alkylbenzene is larger than that of the HFC refrigerant. That is, under a refrigerant having a double bond such as tetrafluoropropene, if an alkylbenzene having a kinematic viscosity at 40 ° C. of approximately 32 cSt or less is applied, the same effect as that obtained when an HFC refrigerant is used can be secured. It can be done.

Embodiment 2. FIG.
In the second embodiment of the present invention, the chemical properties of 3,3,3-tetrafluoropropene and the stabilization of the chemical properties will be described. As described above, 2,3,3,3-tetrafluoropropene has a double bond in its molecular structure, and therefore has the property of being easily decomposed by the application of heat. Therefore, in the first embodiment, the case where the chemical property of the refrigerant is stabilized by adding alcohol having a polarity higher than that of the refrigerant to the refrigerating machine oil as an oily agent has been described as an example. An example will be described in which the chemical properties of the refrigerant are stabilized by adding ester oil having a higher polarity to the refrigerating machine oil as an oily agent.

In the second embodiment, ester oil having higher polarity than the refrigerant and excellent in adsorptivity is added to the refrigerating machine oil as an oily agent. This ester oil desirably has 10 to 40 carbon atoms in its molecular structure. Further, the ester oil is formed by an ester bond between an alcohol and a fatty acid, and it is desirable that the number of carbon atoms of the alcohol and the fatty acid forming the ester oil is 5 to 20, respectively. A typical molecular structure of an ester oil is represented by [CH ₃ — (CH ₂ ) n ₆ —COO— (CH ₂ ) n ₇ —CH ₃ ]. This molecular structure indicates that the ester oil is linear, but the same effect can be obtained even with an ester oil having a branched structure in the molecular structure.

  Therefore, by adding such ester oil to the refrigerating machine oil as an oily agent, this oily agent will adhere to the sliding portion of the rotary compressor, for example, faster than the refrigerant adheres. It is possible to prevent direct contact between the metal materials in the straight portion. Moreover, since a metal contact can be prevented, a friction coefficient can be reduced. That is, since generation | occurrence | production of frictional heat can be suppressed, decomposition | disassembly of the refrigerant | coolant by frictional heat can be prevented effectively, and the chemical property of a refrigerant | coolant can be stabilized.

In addition, as in the first embodiment, it is desirable to apply alkylbenzene having a kinematic viscosity at 40 ° C. of approximately 32 cSt or less as the main component, as in the first embodiment. As described above, the molecular structure of the ester oil is preferably a straight chain as represented by a typical molecular structural formula, but the ester oil is a partly branched ester oil. Even if it exists, the substantially equivalent effect can be acquired. Further, n ₆ and n ₇ are determined so that the total number of carbon atoms is 10 to 40 in each molecular structure.

Embodiment 3.
In Embodiment 3 of the present invention, the chemical properties of 2,3,3,3-tetrafluoropropene and stabilization of the chemical properties will be described. As described above, 2,3,3,3-tetrafluoropropene has a double bond in its molecular structure, and therefore has the property of being easily decomposed by the application of heat. Therefore, in Embodiment 1, alcohol having a polarity higher than that of the refrigerant is used as the oily agent, and in Embodiment 2, ester oil having a polarity higher than that of the refrigerant is added to the refrigerating machine oil as the oily agent, whereby the chemical properties of the refrigerant. The case of stabilizing is described as an example. Furthermore, this Embodiment 3 demonstrates as an example the case where the chemical property of a refrigerant | coolant is stabilized by adding glycol more polar than a refrigerant | coolant to refrigeration oil as an oily agent.

  In the third embodiment, glycols having higher polarity than the refrigerant and excellent in adsorptivity are added to the refrigerating machine oil as an oily agent. The glycols are preferably polyalkylene glycol (PAG), polyethylene glycol (PEG), or polybutylene glycol (PBG). In addition, the structures of both terminal portions of PAG, PEG and PBG are preferably alkyl groups, but may be different. Each of PAG, PEG and PBG may be added to the refrigerating machine oil alone as an oily agent, or any two may be added to the refrigerating machine oil as an oily agent, or all of them may be oily at the same time. You may add to refrigeration oil as an agent.

  Therefore, by adding such glycols to the refrigerating machine oil as an oily agent, the oily agent will adhere to the sliding portion of the rotary compressor, for example, faster than the refrigerant adheres, It is possible to prevent direct contact between the metal materials in the straight portion. Moreover, since a metal contact can be prevented, a friction coefficient can be reduced. That is, since generation | occurrence | production of frictional heat can be suppressed, decomposition | disassembly of the refrigerant | coolant by frictional heat can be prevented effectively, and the chemical property of a refrigerant | coolant can be stabilized. In addition, as in the first and second embodiments, it is desirable to apply alkylbenzene having a kinematic viscosity at 40 ° C. of approximately 32 cSt or less as the main component, as in the first and second embodiments.

Embodiment 4 FIG.
In Embodiment 4 of the present invention, a compressor using tetrafluoropropene, which is an example of a refrigerant having a double bond in the molecular structure described in the above embodiment, will be described.
FIG. 1 is a longitudinal sectional view showing a schematic longitudinal sectional configuration of a rotary compressor 50 which is an example of a compressor. FIG. 2 is a cross-sectional view showing a cross-sectional configuration at the AA portion shown in FIG. Based on FIG.1 and FIG.2, the structure and operation | movement of the rotary compressor 50 which uses tetrafluoro propene as a refrigerant | coolant are demonstrated. The rotary compressor 50 is mounted as one of refrigeration equipment constituting a refrigeration cycle apparatus such as a refrigerator, a freezer, a vending machine, an air conditioner, a refrigeration apparatus, and a water heater.

  The rotary compressor 50 sucks and compresses a refrigerant having a double bond in a molecular structure circulating in the refrigeration cycle, for example, 2,3,3,3-tetrafluoropropene, which is one kind of tetrafluoropropene, and compresses it at a high temperature. It has a function of discharging in a high pressure state. The rotary compressor 50 includes an electric motor unit 51 including a stator 2 and a rotor 3 and a compression mechanism unit 52 driven by the electric motor unit 51 housed in a hermetic container (shell) 1. Yes.

  The compression mechanism portion 52 is rotatably supported by a cylinder 6 whose upper and lower openings are closed by a frame 7 and a cylinder head 8 to form an internal space, and an upper bearing 9 and a lower bearing 10, and has an eccentric portion 4a. The crankshaft 4, a rolling piston 5 that is positioned in the eccentric portion 4 a of the crankshaft 4 and is rotatably installed in the internal space of the cylinder 6, and a notch portion of the cylinder 6, and its tip is the rolling piston 5 The inner space in the cylinder 6 is divided into a low-pressure side suction chamber 15 and a high-pressure side compression chamber 16, and the back surface is pushed out by the pressure of the back pressure chamber 17 secured at a high pressure. 11.

  Further, the suction pipe 12 is connected to the suction chamber 15, and the discharge port 13 is formed in the frame 7 so that the compression chamber 16 and the inside of the sealed container 1 communicate with each other. The rotor 3 is fixed to one end of the crankshaft 4 facing the cylinder 6, and the stator 2 is fixed to the sealed container 1 so as to surround the rotor 3. The eccentric portion 4 a of the crankshaft 4 is provided on one end side of the crankshaft 4 so as to be positioned between the upper bearing 9 and the lower bearing 10. Furthermore, the refrigerating machine oil 14 is stored in the bottom of the sealed container 1. The refrigerating machine oil 14 is an alkylbenzene having a kinematic viscosity at 40 ° C. of approximately 32 cSt or less.

Next, the operation of the rotary compressor 50 will be described.
When the motor unit 51 is energized, the rotor 3 is rotated and the crankshaft 4 fixed to the rotor 3 is rotationally driven. By the rotation of the crankshaft 4, the rolling piston 5 fitted to the eccentric portion 4 a of the crankshaft 4 performs an eccentric rotational movement in the internal space in the cylinder 6. At this time, the vane 11 comes into contact with the outer peripheral surface of the rolling piston 5 by the pressure of the back pressure chamber 17 while changing the amount of extension into the internal space with the eccentric rotational movement of the rolling piston 5, and the cylinder 6 Is divided into a suction chamber 15 and a compression chamber 16.

  Further, the outer peripheral surface of the rolling piston 5 slides on the tip surface of the vane 11 while maintaining a line contact state with the tip surface of the vane 11. Then, the working fluid (refrigerant gas) introduced into the suction chamber 15 via the suction pipe 12 is compressed by the eccentric rotational motion of the rolling piston 5, and when the pressure in the compression chamber 16 rises to a predetermined value, the discharge valve 18 The high-pressure working fluid is discharged from the discharge port 13 into the sealed container 1 and discharged from the discharge pipe 14 to the external refrigeration cycle (see Embodiment 5).

  Here, due to the pump action caused by the rotation of the crankshaft 4 and the differential pressure effect inside the sealed container 1, the refrigerating machine oil 14 is supplied to an oil supply groove (not shown) formed inside the crankshaft 4, and slide bearing (upper The bearing 9 and the lower bearing 10) are lubricated. Further, a part of the refrigerating machine oil 14 supplied to the slide bearing leaks from the both end surfaces of the rolling piston 5 into the internal space of the cylinder 6, and the contact portion between the outer peripheral surface of the rolling piston 5 and the tip of the vane 11 Lubrication of the sliding portion between the vane 11 and the cylinder 6 is performed.

  When 2, 3, 3, 3-tetrafluoropropene is applied as a refrigerant to such a rotary compressor 50, for example, the frictional force is increased at a sliding portion where an oil film is difficult to be formed, such as the tip of the vane 11, Due to the frictional heat, the refrigerant is easily decomposed. Therefore, in the rotary compressor 50 according to the fourth embodiment, a refrigeration in which an alkylbenzene having a kinematic viscosity at 40 ° C. of approximately 32 cSt or less is a main component and an oily agent (for example, alcohol, ester oil or glycols) is added to the alkylbenzene. Machine oil is used.

  Since all of the oily agent added to the refrigerating machine oil has higher polarity and better adsorbability than the 2,3,3,3-tetrafluoropropene refrigerant, the refrigerant is formed between the outer peripheral surface of the rolling piston 5 and the vane 11. It is possible to adhere to the sliding part such as the contact part between the tip part and the sliding part such as the sliding part between the vane 11 and the cylinder 6 earlier. It becomes possible to prevent direct contact. That is, the friction coefficient at the sliding portion can be reduced, and the generation of frictional heat can be prevented. Therefore, the 2,3,3,3-tetrafluoropropene refrigerant is not decomposed by frictional heat, and the ability of this refrigerant can be maintained for a long period of time. In the fourth embodiment, the rotary compressor has been described as an example. However, the present invention is not limited to this, and other types of compressors may be used.

Embodiment 5.
FIG. 3 is a schematic configuration diagram showing a main refrigerant circuit configuration of the refrigeration cycle apparatus 100 according to Embodiment 5 of the present invention. Based on FIG. 3, the structure and operation | movement of the refrigerating-cycle apparatus 100 are demonstrated. The refrigeration cycle apparatus 100 adds the oily agent described in the first to third embodiments to the 2,3,3,3-tetrafluoropropene refrigerant and circulates it, and also performs the rotary compression according to the fourth embodiment. The machine 50 is mounted. The refrigeration cycle apparatus 100 may be an apparatus using a refrigeration cycle (refrigerant circuit), and may be, for example, an air conditioner, a refrigeration apparatus, a heat pump system, a heat pump water heater, a refrigerator, a vending machine, or the like.

  The refrigeration cycle apparatus 100 is configured by sequentially connecting a rotary compressor 50, a condenser 102, a throttle device 103, and an evaporator 104 through a refrigerant pipe 110. The rotary compressor 50 sucks the refrigerant flowing through the refrigerant pipe 110 and compresses the refrigerant to be in a high temperature / high pressure state. The condenser 102 performs heat exchange between a refrigerant that is conducted through the refrigerant pipe 110 and a fluid (air, water, refrigerant, etc.), and condenses and liquefies the refrigerant. The expansion device 103 decompresses and expands the refrigerant conducted through the refrigerant pipe 110. The throttling device 3 may be composed of, for example, a capillary tube or a solenoid valve. The evaporator 104 performs heat exchange between the refrigerant that is conducted through the refrigerant pipe 110 and the fluid, and evaporates and gasifies the refrigerant.

Here, the operation of the refrigeration cycle apparatus 100 will be briefly described.
The refrigerant that has been compressed by the rotary compressor 50 to a high temperature and a high pressure flows into the condenser 102. In the condenser 102, the refrigerant exchanges heat with the fluid to condense, and becomes a low-temperature / high-pressure liquid refrigerant or a gas-liquid two-phase refrigerant. The refrigerant flowing out of the condenser 102 is decompressed by the expansion device 103 and flows into the evaporator 104 as a low-temperature / low-pressure liquid refrigerant or a gas-liquid two-phase refrigerant. In the evaporator 104, the refrigerant exchanges heat with the fluid and evaporates to become a high-temperature / low-pressure refrigerant gas, and is sucked into the rotary compressor 50 again.

  In this refrigeration cycle apparatus 100, an oily agent is added to the refrigeration oil enclosed in the refrigeration cycle so that frictional heat is not generated in the sliding portion or the like inside the compressor. Even when a refrigerant having a bond, for example, 2,3,3,3-tetrafluoropropene, is used, it is possible to prevent the refrigerant from being decomposed by frictional heat. Therefore, it is possible to prevent deterioration of 2,3,3,3-tetrafluoropropene and maintain the capacity of the refrigeration cycle apparatus 100.

It is a longitudinal cross-sectional view which shows the schematic longitudinal cross-sectional structure of the rotary compressor which is an example of a compressor. It is a cross-sectional view which shows the cross-sectional structure in the AA part shown in FIG. FIG. 10 is a schematic configuration diagram showing a main refrigerant circuit configuration of a refrigeration cycle apparatus according to Embodiment 5.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Airtight container, 2 Stator, 3 Rotor, 4 Crankshaft, 4a Eccentric part, 5 Rolling piston, 6 Cylinder, 7 Frame, 8 Cylinder head, 9 Upper bearing, 10 Lower bearing, 11 Vane, 12 Intake pipe, 13 Outlet , 14 Refrigerator oil, 15 Suction chamber, 16 Compression chamber, 17 Back pressure chamber, 18 Discharge valve, 50 Rotary compressor, 51 Electric motor section, 52 Compression mechanism section, 100 Refrigeration cycle apparatus, 102 Condenser, 103 Throttle apparatus, 104 Evaporator, 110 refrigerant piping.

Claims (5)

A refrigerant having a double bond in the molecular structure ;
Refrigerating machine oil used with the refrigerant and having an oily agent;
A compression mechanism for compressing the refrigerant,
The refrigerant is a hydrofluoroolefin,
The oily agent is an alcohol having a monovalent OH group having a higher polarity than the hydrofluoroolefin and having 10 to 25 carbon atoms in the molecular structure.
The compressor is characterized in that the refrigerating machine oil is mainly composed of alkylbenzene having a kinematic viscosity of 32 cSt or less at 40 ° C. The hydrofluoroolefin is tetrafluoropropene,
The compressor according to claim 1 , wherein the oily agent has a higher polarity than the tetrafluoropropene. The compressor according to claim 1 or 2 , wherein the alcoholic agent has a linear molecular structure of the alcohol. The compressor according to claim 1 or 2 , wherein a part of the molecular structure of the alcohol is branched as the oily agent. The compressor as described in any one of the said Claims 1-4 is mounted. The refrigerating-cycle apparatus characterized by the above-mentioned.

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