Compositions, thermal cycling systems, and methods of inhibiting disproportionation reactions of refrigerants

Abstract

The present invention aims to provide a composition in which disproportionation of a refrigerant is inhibited, a heat cycle system using the composition, and a method of inhibiting disproportionation of a refrigerant. The present invention provides a composition containing a refrigerant and a refrigerant oil, characterized in that the refrigerant contains at least one refrigerant selected from the group consisting of HFO-1141, HFO-1132 (E / Z), HFO-1132a, HFO-1123, and FO-1114, and the contact angle of the refrigerant oil with a base material composed of at least one selected from the group consisting of an engineering plastic, an organic film, an inorganic film, glass, and a metal portion is 0.1° ≤ Θ ≤ 90°.

Description

Technical Field

[0001] This invention relates to compositions, thermal cycling systems, and methods for suppressing the disproportionation reaction of refrigerants. Background Technology

[0002] Patent Document 1 discloses a composition for a thermal circulation system containing a working medium for thermal circulation and refrigeration oil. The working medium for thermal circulation includes unsaturated fluorinated hydrocarbon compounds such as trifluoroethylene, 2,3,3,3-tetrafluoropropylene, 1,2-difluoroethylene, 2-fluoropropylene, 1,1,2-trifluoropropylene, (E / Z)-1,2,3,3,3-pentafluoropropylene, (E / Z)-1,3,3,3-tetrafluoropropylene, and 3,3,3-trifluoropropylene. The refrigeration oil has an insulation breakdown voltage of 25 kV or higher, a hydroxyl value of 0.1 mg KOH / g or lower, and an aniline point of -100°C or higher or 0°C or lower.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Re-publication Patent No. 2015 / 125884 Summary of the Invention

[0006] The technical problem that the invention aims to solve

[0007] The object of the present invention is to provide a composition that inhibits the disproportionation of a refrigerant, a thermal cycling system using the composition, and a method for inhibiting the disproportionation reaction of a refrigerant.

[0008] Technical solutions for solving technical problems

[0009] The present invention includes the technical features described in the following items.

[0010] Item 1. A composition comprising a refrigerant and a refrigeration oil, characterized in that the refrigerant comprises at least one refrigerant selected from monofluoroethylene (HFO-1141), trans-1,2-difluoroethylene (HFO-1132(E)), cis-1,2-difluoroethylene (HFO-1132(Z)), 1,1-difluoroethylene (HFO-1132a), trifluoroethylene (HFO-1123) and tetrafluoroethylene (FO-1114), and the refrigeration oil has a contact angle of 0.1°≤Θ≤90° with a substrate made of at least one selected from engineering plastics, organic films, inorganic films, glass and metal parts.

[0011] Item 2. The composition as described in Item 1 above, wherein the insulation breakdown voltage of the refrigeration oil is 10kV or higher.

[0012] Item 3. The composition as described in Item 1 or 2 above, wherein the refrigeration oil is selected from at least one of polyalkylene glycol (PAG), polyol ester (POE), and polyvinyl ether (PVE).

[0013] Item 4. The composition as described in any one of items 1 to 3 above, wherein the composition is used as a working fluid containing refrigeration oil.

[0014] Item 5. The composition as described in any one of items 1 to 4 above, wherein the composition is used in a thermal cycling system.

[0015] Item 6. A thermal cycling system wherein the composition of any one of claims 1 to 5 is used.

[0016] Item 7. The thermal circulation system as described in Item 6 above, wherein the thermal circulation system is selected from at least one of refrigeration / cooling equipment, air conditioning equipment, power generation system, heat transfer device and secondary cooler.

[0017] Item 8. The thermal cycling system as described in Item 6 or 7 above, wherein the thermal cycling system has a compression mechanism, the compression mechanism having a contact portion that contacts the thermal cycling system composition of the compression mechanism, the contact portion being composed of at least one selected from engineering plastics, organic films, inorganic films, glass and metal parts.

[0018] Item 9. The thermal cycling system as described in Item 8 above, wherein the contact portion is made of at least one engineering plastic selected from polyamide resin, polyphenylene sulfide resin, polyacetal resin, polybutylene terephthalate resin, and fluoropolymer resin.

[0019] Item 10. A method for suppressing the disproportionation reaction of a refrigerant using refrigeration oil, wherein the refrigerant comprises at least one refrigerant selected from monofluoroethylene (HFO-1141), trans-1,2-difluoroethylene (HFO-1132(E)), cis-1,2-difluoroethylene (HFO-1132(Z)), 1,1-difluoroethylene (HFO-1132a), trifluoroethylene (HFO-1123) and tetrafluoroethylene (FO-1114), and the refrigeration oil has a contact angle of 0.1° ≤ Θ ≤ 90° with a substrate made of at least one selected from engineering plastics, organic films, inorganic films, glass and metal parts.

[0020] Item 11. The method as described in Item 10 above, wherein the insulation breakdown voltage of the refrigeration oil is 10kV or higher.

[0021] Item 12. The method as described in Item 10 or 11 above, wherein the refrigeration oil is selected from at least one of polyalkylene glycol (PAG), polyol ester (POE), and polyvinyl ether (PVE).

[0022] The effects of the invention

[0023] The present invention provides a composition that inhibits the disproportionation of refrigerant.

[0024] The present invention can provide a thermal cycling system using a composition that suppresses refrigerant disproportionation.

[0025] The present invention provides a method for suppressing the disproportionation reaction of a refrigerant contained in a composition. Detailed Implementation

[0026] The inventors of this invention, after conducting in-depth research to improve the stability of the refrigerant (working medium for thermal cycling) in a refrigerant-containing composition, discovered that this objective can be achieved by coexisting with refrigeration oil having a contact angle with the substrate of 0.1°≤Θ≤90° (indicating wettability).

[0027] The inventors of this invention have discovered that, in particular, by making the insulation breakdown voltage of the aforementioned refrigeration oil 10kV or higher, the stability of the refrigerant can be further improved.

[0028] The embodiments included in this invention will be described in detail below.

[0029] <Definition of Terms>

[0030] In this specification, the term "refrigerant" includes at least compounds marked with a refrigerant number (ASHRAE number) that begins with R as specified by ISO 817 (International Organization for Standardization) to indicate the type of refrigerant, and also includes substances that, although not marked with a refrigerant number, have the same properties as them as refrigerants.

[0031] From the perspective of compound structure, refrigerants are broadly classified into "fluorocarbon compounds" and "non-fluorocarbon compounds." "Fluorocarbon compounds" include hydrochlorofluorocarbons (HCFCs) and hydrofluorocarbons (HFCs). Examples of "non-fluorocarbon compounds" include propane (R290), propylene (R1270), butane (R600), and isobutane (R600a).

[0032] In this specification, the term "composition containing refrigerant" includes at least (1) the refrigerant itself (including refrigerant mixtures); (2) a composition that also contains other components and is capable of being used to obtain a refrigeration working fluid by mixing with at least refrigeration oil; and (3) a refrigeration working fluid containing refrigeration oil.

[0033] In this specification, in all three methods, the composition of (2) is distinguished from the refrigerant itself (including mixtures of refrigerants) and is described as a "refrigerant composition".

[0034] Furthermore, in this specification, the working fluid for refrigeration equipment in (3) is distinguished from "refrigerant composition" and is described as "working fluid containing refrigeration oil".

[0035] In this specification, the term "replacement" is used in the context of "replacing" the first refrigerant with the second refrigerant. As a first type, it means that in equipment designed to operate using the first refrigerant, the second refrigerant can be used to operate under optimal conditions as required by only minor changes to components (refrigeration oil, gasket, packing, expansion valve, dryer, at least one of other components) and equipment adjustments.

[0036] In other words, this type refers to "replacing" the refrigerant to make the same equipment work. As for the methods of "replacing" in this type, depending on the degree of change or adjustment required when replacing with a second refrigerant, they can be "direct (drop-in) replacement", "nearly direct (drop-in) replacement" and "retrofit" in order from smallest to largest.

[0037] As a second type, the use of a second refrigerant for the purpose of using equipment designed to operate with a second refrigerant for the same purpose as the existing use of the first refrigerant also falls under the term "substitution." This type refers to "substituting" a refrigerant to provide the same purpose.

[0038] In this specification, the term "refrigerator" refers to any device that reduces the temperature of an object or space to a lower temperature than the surrounding external atmosphere and maintains that low temperature by removing heat from the object or space. In other words, a refrigerator is an energy conversion device that converts energy by moving heat from a lower temperature to a higher temperature, obtaining energy from the outside, and performing work.

[0039] In this specification, the terms “containing” and “comprising” include the concepts of “containing,” “comprising,” “substantially constituted by,” and “consisting solely of.”

[0040] In this specification, when the numerical range is recorded in segments, the upper or lower limit of the numerical range of a certain segment can be arbitrarily combined with the upper or lower limit of the numerical range of other segments.

[0041] In this specification, the upper or lower limits of the numerical ranges described may be replaced with the values ​​shown in the embodiments or values ​​that can be unambiguously derived from the embodiments.

[0042] In this specification, the following is stated.

[0043] Monofluoroethylene: HFO-1141;

[0044] trans-1,2-difluoroethylene: HFO-1132(E)((E)-1,2-difluoroethylene);

[0045] cis-1,2-difluoroethylene: HFO-1132(Z)((Z)-1,2-difluoroethylene);

[0046] (E) and / or (Z)-1,2-difluoroethylene: HFO-1132(E / Z);

[0047] "(E / Z)" means including the E-body (trans-body) and / or the Z-body (cis-body).

[0048] 1,1-Difluoroethylene: HFO-1132a;

[0049] Trifluoroethylene: HFO-1123;

[0050] Tetrafluoroethylene: FO-1114.

[0051] [1] Composition

[0052] (1) Refrigerant

[0053] The composition of the present invention contains a refrigerant (working medium for thermal cycling), wherein the refrigerant comprises at least one refrigerant selected from vinyl monofluoroethylene (HFO-1141), trans-1,2-difluoroethylene (HFO-1132(E)), cis-1,2-difluoroethylene (HFO-1132(Z)), 1,1-difluoroethylene (HFO-1132a), trifluoroethylene (HFO-1123) and tetrafluoroethylene (FO-1114).

[0054] In the composition of the present invention, the refrigerant preferably functions as a working medium for thermal cycling, and the composition is useful in thermal cycling systems.

[0055] The method of manufacturing the refrigerant to be contained in the composition of the present invention is not particularly limited, and various refrigerants can be manufactured by known manufacturing methods. In the case of HFO-1132(E / Z) as the refrigerant, HFO-1132(E / Z) can be manufactured by dehydrofluorination of 1,1,2-trifluoroethane (HFC-143), hydrogenation of (E) and / or (Z)-1,2-dichloro-1,2-difluoroethylene (CFO-1112(E / Z)), or dehydrochlorination of 1-chloro-1,2-difluoroethane (HCFC-142a).

[0056] In the compositions of the present invention, the total amount of refrigerant can be determined by gas chromatography.

[0057] The refrigerant contained in the above composition is preferably substantially composed of only at least one refrigerant selected from HFO-1141, HFO-1132(E / Z), HFO-1132a, HFO-1123 and FO-1114.

[0058] The refrigerant contained in the above composition may also include compounds other than at least one refrigerant selected from HFO-1141, HFO-1132(E / Z), HFO-1132a, HFO-1123 and FO-1114.

[0059] In the compositions of the present invention, the content of the refrigerant is not particularly limited, but is generally preferably 95% by mass or less, more preferably 90% by mass or less, even more preferably 80% by mass or less, particularly preferably 70% by mass or less, and most preferably 60% by mass or less, relative to the total composition. The content of the refrigerant relative to the total composition is preferably 5% by mass or more, more preferably 10% by mass or more, even more preferably 20% by mass or more, particularly preferably 30% by mass or more, and most preferably 40% by mass or more.

[0060] Other refrigerants may contain impurities (unavoidable impurities) that may be introduced during the manufacture of the aforementioned refrigerants.

[0061] In the case of, for example, HFO-1132(E / Z), the aforementioned impurities can be hydrogen fluoride, fluoroethylene, HFO-1123, 1,1,1-trifluoroethane, propylene, acetylene, difluoromethane (HFC-32), trifluoromethane, fluoromethane, HFO-1123, 1,1-difluoroethane (HFC-152a), fluoroethane (HFC-161), 1,1,2-trifluoroethane (HFC-143), 2-chloro-1,1,1-trifluoroethane (HCFC-133b), 1-chloro-1,1,2-trifluoroethane (HCFC-133), 1,1-dichloro-2,2,2-trifluoroethane (HCFC-123), 1-chloro-1,2-difluoroethane (HCFC-142a), 1,2-difluoroethane (HFC-152), and dichlorofluoromethane (HCFC-152). FC-22), 1,1,1,2-tetrafluoroethane (HFC-134a), 1,1,2,2-tetrafluoroethane (HFC-134), pentafluoroethane (HFC-125), 2,3,3,3-tetrafluoropropylene (HFO-1234yf), 1,2,3,3,3-pentafluoropropylene (HFO-1225ye), 1,3,3,3-tetrafluoropropylene (HFO-1234ze), 1,3,3,3-tetrafluoropropylene (HFO-1234ze), fluoroethylene (HFO-1141), 3,3,3-trifluoropropylene (HFO-1243zf), 1,1-difluoroethylene (HFO-1132a), 1-chloro-2,2-difluoroethylene (HCFO-1122), 1-chloro-1,2-difluoroethylene (HCFO-1122a), ethylene, etc.

[0062] Other refrigerants include 2-fluoropropylene (HFO-1261yf), 1,1,2-trifluoropropylene (HFO-1243yc), (E)-1,2,3,3,3-pentafluoropropylene (HFO-1225ye(E)), (Z)-1,2,3,3,3-pentafluoropropylene (HFO-1225ye(Z)), (E)-1,3,3,3-tetrafluoropropylene (HFO-1234ze(E)), (Z)-1,3,3,3-tetrafluoropropylene (HFO-1234ze(Z)), and 3,3,3-trifluoropropylene (HFO-1243zf).

[0063] Other refrigerants include difluoromethane (HFC-32), 1,1-difluoroethane (HFC-152a), 1,1,1-trifluoroethane (HFC-143a), 1,1,2,2-tetrafluoroethane (HFC-134), 1,1,1,2-tetrafluoroethane (HFC-134a), and 1,1,1,2,2-pentafluoroethane (HFC-125).

[0064] Other refrigerants include hydrocarbons such as propane, propylene, cyclopropane, butane, isobutane, pentane, and isopentane.

[0065] Other refrigerants include chlorofluoroolefins such as 1,1-dichloro-2,3,3,3-tetrafluoropropylene (CFO-1214ya), 1,3-dichloro-1,2,3,3-tetrafluoropropylene (CFO-1214yb), and 1,2-dichloro-1,2-difluoroethylene (CFO-1112).

[0066] Other refrigerants include hydrochlorofluoroolefins such as 1-chloro-2,3,3,3-tetrafluoropropylene (HCFO-1224yd) and 1-chloro-1,2-difluoroethylene (HCFO-1122a).

[0067] Other refrigerants may be contained individually or in combination of two or more.

[0068] When the refrigerant contained in the composition of the present invention contains other refrigerants and impurities as described above, their content is not particularly limited. For example, it may contain approximately 0.1 ppm or more and 10,000 ppm or less by weight. Within this range, there are fewer concerns about the stabilizing effect of the refrigerant in the composition being hindered.

[0069] (2) Refrigeration oil

[0070] The composition of the present invention contains the above-mentioned refrigerant and refrigeration oil, and is preferably used as a working fluid in a refrigeration unit (refrigeration unit working fluid) or a working fluid containing refrigeration oil.

[0071] Specifically, the composition of the present invention is obtained as a working fluid containing refrigeration oil by mixing refrigeration oil used in the compressor of a refrigeration machine with the refrigerant.

[0072] The composition of the present invention changes during the refrigeration cycle by containing refrigeration oil. Specifically, the refrigeration oil content of the composition of the present invention is relatively high in the compressor and relatively low during the period from when it is discharged from the compressor as a mist, circulates in the refrigeration cycle, and returns to the compressor. For example, the refrigeration oil content of the composition of the present invention is 30% to 70% by mass in the compressor and preferably 0 to 20% by mass during the period from when it is discharged from the compressor and returns to the compressor, more preferably 1 ppm to 10% by mass.

[0073] The contact angle between the aforementioned refrigeration oil and the substrate is 0.1°≤Θ≤90°.

[0074] When refrigerants such as HFO-1141, HFO-1132(E / Z), HFO-1132a, HFO-1123, and FO-1114 are used as refrigerants in the compositions of the present invention, these refrigerants may undergo a disproportionation reaction under certain pressure and temperature conditions if an ignition source is present.

[0075] The stability of refrigerants can sometimes be maintained by suppressing ignition sources within the compressor, ensuring the refrigerant in the composition does not disproportionate, and controlling the temperature and pressure within the compressor. In other words, there are situations where refrigerant disproportionation can be suppressed. However, in a thermal cycle system where the compressor is in operation and the pressure and temperature at which the refrigerant may disproportionate are reached, measures to prevent refrigerant disproportionation are necessary.

[0076] For example, discharge phenomena between terminals or between coils can be listed as potential ignition sources within the compressor.

[0077] Discharge at the terminals refers to the discharge phenomenon that occurs when metal powder or carbides accumulate between the terminal and the compressor material. Furthermore, discharge between coils refers to the discharge phenomenon that occurs between copper coils coated with resin when the resin is damaged or melts under overheating conditions.

[0078] In the composition of the present invention, the refrigeration oil used has a contact angle of 0.1°≤Θ≤90° with the substrate (e.g., glass (wiring material), copper (coil) etc.).

[0079] Furthermore, since the maximum voltage generated inside the compressor is about 2kV, the composition of the present invention can prevent discharge by containing specific refrigeration oil, especially by using refrigeration oil with an insulation breakdown voltage higher than about 2kV.

[0080] The aforementioned refrigeration oils can also improve the lubrication properties of the aforementioned refrigerants.

[0081] (3) Contact angle between refrigeration oil and substrate

[0082] The contact angle between the refrigeration oil contained in the composition of the present invention and a substrate made of at least one selected from engineering plastics, organic films, inorganic films, glass and metal parts is 0.1°≤Θ≤90°.

[0083] In this invention, the parameter used to quantify the wetting degree of refrigeration oil is called "contact angle" (Θ), which is defined as "the angle between the liquid surface and the solid surface at the point where the free surface of a stationary liquid contacts a solid wall (taking the angle inside the liquid)".

[0084] The contact angle (wetting property) of refrigeration oil is determined by measuring the contact angle formed by the refrigeration oil droplet on the substrate surface. The angle θ between the line of the refrigeration oil droplet on the substrate surface and the substrate (solid surface) is defined as the "contact angle".

[0085] In this invention, the contact angle between the refrigeration oil and the substrate (for evaluating the wettability of the substrate) is measured as described in the examples, referring to... JIS R3257 The procedure is performed using the static drip method.

[0086] In the composition for a thermal cycling system of the present invention, the substrate is a contact part existing inside the compressor that comes into contact with the composition for a thermal cycling system, and is an engineering plastic, organic film, inorganic film, glass (wiring material), copper (coil) or other metals.

[0087] When the contact angle is less than 0.1°, the film thickness of the refrigeration oil on the substrate surface decreases, thus reducing the insulation breakdown voltage and causing discharge at the ignition source. On the other hand, when the contact angle is greater than 90°, there may be areas on the substrate surface that are not covered by refrigeration oil, which can also cause discharge at the ignition source.

[0088] The contact angle (Θ) between the refrigeration oil and the substrate is 0.1° ≤ Θ ≤ 90°. The contact angle (Θ) between the refrigeration oil and the substrate is 0.1° or more, preferably 1° or more, and more preferably 10° or more. The contact angle (Θ) between the refrigeration oil and the substrate is 90° or less, preferably 80° or less, and more preferably 70° or less.

[0089] In the composition of the present invention, since the contact angle between the refrigeration oil and the substrate is 0.1° or more and 90° or less, it exhibits good wettability and can effectively cover the ignition source with the refrigeration oil. Therefore, it can prevent discharge in the thermal cycling system and suppress refrigerant disproportionation.

[0090] (4) Insulation breakdown voltage of refrigeration oil

[0091] The refrigeration oil contained in the composition of the present invention preferably has an insulation breakdown voltage of 15kV or higher.

[0092] In this invention, the insulation breakdown voltage of the refrigeration oil is as described in the embodiments, referring to... JIS C2101 The measurement should be performed. Additionally, the insulation breakdown voltage can be confirmed as being above 10kV by checking the nominal value of the insulation breakdown voltage of the refrigeration oil, or by using a simplified verification method based on JIS C2101.

[0093] Since the maximum voltage occurring inside the compressor is about 2kV, the composition of the present invention can prevent discharge, particularly by using refrigeration oil with an insulation breakdown voltage higher than about 2kV.

[0094] In the composition of the present invention, as a refrigeration oil, by using a refrigeration oil with an insulation breakdown voltage of 10kV or more, insulation can be maintained even in a thermal cycle system where the electromagnet used for driving is in direct contact with the refrigeration oil, and stable operation can be achieved.

[0095] The insulation breakdown voltage of the above-mentioned refrigeration oil is preferably above 10kV, more preferably above 15kV, even more preferably above 20kV, and particularly preferably above 30kV.

[0096] (5) Types of Refrigeration Oil

[0097] The composition of the present invention contains refrigeration oil and is used as a working fluid in a refrigeration unit. Specifically, it is obtained by mixing the refrigeration oil used in the compressor of the refrigeration unit with a refrigerant (working medium for heat circulation).

[0098] There are no particular limitations on the aforementioned refrigeration oil, and it can be appropriately selected from commonly used refrigeration oils. At this time, depending on the needs, it is possible to appropriately select a refrigeration oil that is superior in terms of improving the miscibility of the mixture with the working medium (refrigerant) for the thermal cycle of the present invention and improving the stability of the mixed refrigerant of the present invention.

[0099] From a lubrication point of view, the dynamic viscosity of the above-mentioned refrigeration oil at 40°C is preferably above 5 cSt and below 400 cSt.

[0100] The aforementioned refrigeration oil preferably contains at least one polymer selected from polyalkylene glycol (PAG), polyol ester (POE), and polyvinyl ether (PVE). The aforementioned refrigeration oil may contain only one polymer or two or more polymers.

[0101] Examples of polyalkylene glycols (PAGs) include "SUNICE P56" manufactured by Japan Sun Oil Co., Ltd. Examples of polyol esters (POEs) include "Ze-GLES RB32" manufactured by JX Nippon Oil & Gas Co., Ltd.

[0102] In the composition of the present invention, the content of the above-mentioned refrigeration oil is not particularly limited, but is generally preferably 5% by mass or more, more preferably 10% by mass or more, even more preferably 20% by mass or more, particularly preferably 30% by mass or more, and most preferably 40% by mass or more, relative to the total composition. Regarding the content of the above-mentioned refrigeration oil, relative to the total composition, it is preferably 95% by mass or less, more preferably 90% by mass or less, even more preferably 80% by mass or less, particularly preferably 70% by mass or less, and most preferably 60% by mass or less.

[0103] (6) Additives for refrigeration oil

[0104] In addition to the base oil containing refrigeration oil, the composition of the present invention may also contain additives. The additives are preferably compatibilizers. The additives may also be at least one selected from compatibilizers, antioxidants, extreme pressure agents, acid scavengers, oxygen scavengers, copper passivators, rust inhibitors, oiliness agents, and defoamers.

[0105] In the composition of the present invention, the compatibilizer may be one type or two or more types.

[0106] There are no particular limitations on the compatibilizers mentioned above, and they can be appropriately selected from commonly used compatibilizers. Examples of such compatibilizers include polyoxyalkylene glycol ethers, amides, nitriles, ketones, chlorinated hydrocarbons, esters, lactones, aryl ethers, fluoroethers, and 1,1,1-trifluoroalkanes. Among these, polyoxyalkylene glycol ethers are preferred.

[0107] In the composition of the present invention, by having the refrigerant and refrigeration oil coexist, discharge can be suppressed, refrigerant disproportionation can be suppressed, and the refrigerant stability is excellent.

[0108] (7) Method for preparing the composition

[0109] The method for preparing the compositions of the present invention is not particularly limited.

[0110] As a method for preparing the composition of the present invention, for example, a method can be described by mixing the above-mentioned refrigerant and refrigeration oil, and additives for refrigeration oil as needed, in a prescribed proportion.

[0111] [2] Thermal circulation system

[0112] (1) Thermal Cycling System

[0113] The refrigerant contained in the composition of the present invention preferably functions as a working medium in a thermal cycling system, and the composition of the present invention is useful in a thermal cycling system.

[0114] The thermal circulation system of the present invention is a system that uses the composition of the present invention, preferably at least one selected from refrigeration / cooling equipment, air conditioning equipment, power generation system, heat transfer device and secondary cooler.

[0115] The thermal cycle system of the present invention can be a heat pump system that utilizes heat obtained from the condenser, or a refrigeration cycle system that utilizes cold obtained from the evaporator.

[0116] Specific examples of the thermal circulation system of the present invention include refrigeration / cooling equipment, air conditioning equipment, power generation systems, heat transfer devices, and secondary coolers. Since the thermal circulation system of the present invention can efficiently perform its thermal circulation function even in high-temperature operating environments, it is preferably used in air conditioning equipment, which is mostly installed outdoors. Furthermore, the thermal circulation system of the present invention is also preferably used in refrigeration / cooling equipment.

[0117] As refrigeration / freezing equipment, specific examples include display cases (built-in display cases, freestanding display cases, etc.), commercial freezers / refrigerators, vending machines, ice makers, etc.

[0118] As for air conditioning equipment, specific examples include indoor air conditioners, packaged air conditioners (shop packaged air conditioners, building packaged air conditioners, equipment packaged air conditioners, etc.), gas engine heat pumps, train air conditioning units, and automobile air conditioning units.

[0119] As a power generation system, a Rankine cycle system is preferred. Specifically, a power generation system can be exemplified by using geothermal energy, solar heat, or waste heat in the medium to high temperature range (50°C to 200°C) to heat the working medium, which becomes steam under high temperature and pressure. This working medium is then adiabatically expanded using an expander, and the work generated by this adiabatic expansion is used to drive a generator to generate electricity.

[0120] The thermal circulation system of the present invention can also be a heat transfer device.

[0121] As a heat transfer device, a latent heat transfer device is preferred. Examples of latent heat transfer devices include heat pipes and two-phase closed-loop thermosiphons, which utilize the evaporation, boiling, and condensation of the working medium sealed within the device. Heat pipes are suitable for relatively small cooling devices such as those for semiconductor components and heat-generating parts of electronic devices. Two-phase closed-loop thermosiphons, due to their simple structure and lack of a wick, are widely used in gas-to-gas heat exchangers, promoting snow melting on roads, and preventing freezing.

[0122] The thermal cycling system of the present invention preferably has a compression mechanism having a contact portion that contacts the composition of the thermal cycling system described above, the contact portion being composed of at least one selected from engineering plastics, organic films, inorganic films, glass, and metal.

[0123] (2) Contact portion that comes into contact with the composition

[0124] As a thermal cycle system to which the compositions of the present invention are applicable, thermal cycle systems utilizing heat exchangers such as condensers and evaporators can be used without particular limitation. In a thermal cycle system, for example in a refrigeration cycle, a mechanism is included where a working medium of gas is compressed by a compressor, cooled in a condenser to produce a high-pressure liquid, the pressure is reduced using an expansion valve, and low-temperature vaporization is performed in an evaporator to remove heat using the heat of vaporization.

[0125] The contact portion that comes into contact with the composition of the present invention is a part existing inside the compressor, and preferably the contact portion is composed of at least one selected from engineering plastics, organic films, inorganic films, glass (wiring materials, etc.), and metal parts (copper (coil), cast iron (shaft part, wiring materials), etc.).

[0126] Among the aforementioned contact parts, those requiring special protection include the sliding parts of a compressor and the sealing parts inside a thermal cycle system. More specifically, examples include sliding components (bearings, etc.) installed in the sliding part of the compressor, sealing components used to prevent leakage of the working medium at the compressor's clearances, and insulating materials disposed in the electric motor.

[0127] The engineering plastic constituting the above-mentioned contact portion is preferably at least one material selected from polyamide resin, polyphenylene sulfide resin, polyacetal resin, polybutylene terephthalate resin, and fluoropolymer resin.

[0128] The organic film is preferably selected from at least one material chosen from polytetrafluoroethylene coated film, polyimide coated film, polyamide-imide coated film, and thermosetting insulating film, wherein the thermosetting insulating film is formed using a resin coating containing a resin composed of polyhydroxy ether resin and polysulfone resin and a crosslinking agent.

[0129] The inorganic membrane is preferably selected from at least one material chosen from graphite membrane, diamond-like carbon membrane, tin membrane, chromium membrane, nickel membrane and molybdenum membrane.

[0130] When the contact part is a sliding component, the raw materials preferably include polytetrafluoroethylene, polyphenylene sulfide, and polyamide. Furthermore, when the sliding component (shaft, etc.) is metal, the metal preferably includes SUS, cast iron, etc.

[0131] When the contact part is a sealing part, the raw material is preferably selected from at least one material selected from polytetrafluoroethylene, polyphenylene sulfide, chloroprene rubber, silicone rubber, hydrogenated nitrile rubber, fluororubber and epichlorohydrin rubber.

[0132] As insulating materials for electric motors, there are insulating covering materials and insulating films for stator coils. Among these insulating covering materials and insulating films, resins that do not undergo physical or chemical modification due to the working medium even when in contact with high-temperature and high-pressure working media are used, especially resins with solvent resistance, extraction resistance, thermal stability, chemical stability, and foaming resistance.

[0133] For the insulating coating material of the stator coil, polyvinyl acetal, polyester, THEIC modified polyester, polyamide, polyamide-imide, polyester-imide, and polyester-amide-imide are preferred.

[0134] The insulation material for the stator coils is preferably a double-coated wire with an upper layer of polyamide-imide and a lower layer of polyester-imide. In addition to the above-mentioned materials, an enamel coating with a glass transition temperature of 120°C or higher is preferably used.

[0135] The insulating film is preferably made of polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyphenylene sulfide (PPS), or polybutylene terephthalate (PBT). The insulating film is preferably made of a foaming material that is the same as the working medium of the refrigeration cycle.

[0136] For insulating materials used in insulators and other retaining coils, polyetheretherketone (PEEK) and liquid crystal polymer (LCP) are preferred. Epoxy resin is preferred for varnish.

[0137] The compositions of this invention suppress refrigerant disproportionation and can be used in thermal cycling systems. The compositions of this invention suppress discharge and provide thermal cycling systems with excellent refrigerant stability.

[0138] The thermal cycling system of the present invention can achieve practically sufficient cycling performance by using the composition of the present invention.

[0139] [3] Methods to suppress disproportionation reaction

[0140] The method for suppressing disproportionation reaction of the present invention is a method for suppressing the disproportionation reaction of refrigerant using refrigeration oil, wherein the refrigerant comprises at least one refrigerant selected from HFO-1141, HFO-1132(E / Z), HFO-1132a, HFO-1123 and FO-1114, and the contact angle between the refrigeration oil and a substrate composed of at least one selected from engineering plastics, organic films, inorganic films, glass and metal parts is 0.1°≤Θ≤90°.

[0141] Disproportionation refers to a chemical reaction in which two or more chemical substances of the same kind (such as HFO-1132(E) and other components of ethylene-based fluorinated hydrocarbons with double bonds) react with each other to produce two or more different kinds of products.

[0142] The method for suppressing disproportionation reaction of the present invention, by having the above-described features, has the characteristic of suppressing the disproportionation reaction of at least one refrigerant selected from HFO-1141, HFO-1132(E / Z), HFO-1132a, HFO-1123 and FO-1114.

[0143] In the method for suppressing disproportionation reaction of the present invention, a refrigeration oil with a contact angle of 0.1°≤Θ≤90° with the substrate is added as a disproportionation inhibitor to at least one refrigerant (or a composition containing these refrigerants) selected from HFO-1141, HFO-1132(E / Z), HFO-1132a, HFO-1123 and FO-1114, thereby suppressing the disproportionation reaction of the refrigerant, wherein the substrate is composed of at least one selected from engineering plastics, organic films, inorganic films, glass and metal parts.

[0144] In the method for suppressing disproportionation reaction of the present invention, the refrigeration oil preferably has an insulation breakdown voltage of 10kV or higher. The refrigeration oil is preferably selected from at least one of polyalkylene glycol (PAG), polyol ester (POE), and polyvinyl ether (PVE).

[0145] The method for suppressing disproportionation reaction of the present invention is preferably applicable to compositions used as working fluids containing refrigeration oil, or compositions used in thermal cycling systems.

[0146] The refrigerant, refrigeration oil, and other components used in the method for suppressing disproportionation reactions can be the same components described in the above-mentioned composition and thermal cycle system.

[0147] Example

[0148] The present invention will be described in more detail below through embodiments, but is not limited to these embodiments.

[0149] (1) Preparation of the composition (1-1) Refrigerant (working medium for thermal cycling)

[0150] Monofluoroethylene (HFO-1141);

[0151] trans-1,2-difluoroethylene (HFO-1132(E));

[0152] cis-1,2-difluoroethylene (HFO-1132(Z));

[0153] 1,1-Difluoroethylene (HFO-1132a);

[0154] Trifluoroethylene (HFO-1123);

[0155] Tetrafluoroethylene (FO-1114).

[0156] (1-2) Refrigeration oil (contact angle with substrate is 0.1°≤Θ≤90°)

[0157] Evaluation of the wettability of refrigeration oils to substrates (JIS) R3257)

[0158] The wettability of refrigeration oil to the substrate was evaluated according to JIS R3257. The test was conducted using the static drop method, with the temperature set at 25°C and the droplet volume at 1 μL. The contact angle was evaluated using an automatic contact angle meter. Image analysis was used to read the angle when a straight line connects the apex of the droplet to the interface with the droplet, and this angle was multiplied by two to calculate the contact angle Θ. Measurements were performed on droplets that had been allowed to stand for less than one minute after dropping.

[0159] The substrate uses the polyamide-imide resin used in copper coil coating.

[0160] Evaluation of insulation breakdown voltage of refrigeration oil (JIS) C2101)

[0161] The insulation breakdown voltage of refrigeration oil was evaluated according to JIS C2101. Using opposing ball electrodes with an electrode gap adjusted to 2.5 mm and a diameter of 12.5 mm, the voltage was increased at a rate of approximately 3 kV per second to determine the insulation breakdown voltage of the test oil at commercial frequencies.

[0162] Polyol esters (POE)

[0163] Refrigeration oil A: Polyol ester refrigeration oil (trade name: UNISTER RH-208BRS, Nippon Oil Co., Ltd.), contact angle with substrate: 25°, insulation breakdown voltage: ≥20kV.

[0164] Refrigeration oil B: Polyol ester refrigeration oil (trade name: UNISTER RH-481R, Nippon Oil Co., Ltd.), contact angle with substrate: 30°, insulation breakdown voltage: ≥20kV.

[0165] Refrigeration oil C: Polyol ester refrigeration oil (trade name: UNISTER RHR-32, Nippon Oil Co., Ltd.), contact angle with substrate: 34°, insulation breakdown voltage: ≥20kV.

[0166] Refrigeration oil D: Polyol ester refrigeration oil (trade name: UNISTER RHR-64, Nippon Oil Co., Ltd.), contact angle with substrate: 28°, insulation breakdown voltage: 20kV or higher.

[0167] Refrigeration oil E: Polyol ester refrigeration oil (trade name: UNISTER RHR-200, Nippon Oil Co., Ltd.), contact angle with substrate: 38°, insulation breakdown voltage: ≥20kV.

[0168] Refrigeration oil F: Polyol ester refrigeration oil (trade name: UNISTER RHR-609BR, Nippon Oil Co., Ltd.), contact angle with substrate: 40°, insulation breakdown voltage: ≥20kV.

[0169] Refrigeration oil G: Refrigeration oil with polyol ester as the main component (trade name: Ze-GLESRB-68, product of JX Nippon Minerals Energy Co., Ltd.), contact angle with substrate: 25°, insulation breakdown voltage: 20kV or above.

[0170] Polyvinyl ether (PVE)

[0171] Refrigeration Oil H: Refrigeration oil with polyvinyl ether as the main component (trade name: Daphne Hermetic Oil FVC68D, product of Idemitsu Kosan Co., Ltd.), contact angle with substrate: 31°, insulation breakdown voltage: 20kV or higher.

[0172] Polyalkylene glycol (PAG)

[0173] Refrigeration Oil I: Polyalkylene glycol-based refrigeration oil (trade name: SUNICE P 56, product of Taiyo Oil Co., Ltd., Japan), contact angle with substrate: 32°, insulation breakdown voltage: ≥20kV.

[0174] (1-3) Preparation method

[0175] The composition is manufactured by mixing and dissolving 50% by mass of refrigerant and 50% by mass of refrigeration oil. In the refrigeration oil, an antioxidant (2,6-di-tert-butyl-4-methylphenol) is added as an additive in such a manner that it reaches 0.5% by mass when the total amount of refrigeration oil and antioxidant is set to 100% by mass.

[0176] (2) Discharge test method

[0177] Discharge suppression tests were performed on each of the compositions obtained in the examples and comparative examples.

[0178] (2-1) Whether there is discharge

[0179] To simulate the discharge between coils that act as an ignition source within the compressor, the electrode gap was set to 0.1 mm during the discharge test. The voltage was increased by 0.3 kV each time, up to a maximum of 3 kV. This operation was repeated 5 times, and the following items were evaluated.

[0180] Other conditions shall be evaluated in accordance with JIS C2101.

[0181] "×" rating: At least one discharge occurred in the refrigeration oil during the discharge test.

[0182] "○" rating: No discharge occurred even once during the discharge test.

[0183] (2-2) Hue Evaluation

[0184] After the discharge test, the composition for the thermal cycling system was removed, and the hue of the refrigeration oil was evaluated according to ASTM-D156.

[0185] “○”: The color of the refrigeration oil did not change.

[0186] "×": The hue of the refrigeration oil has been colored.

[0187] (2-3) Presence or absence of silt

[0188] After the discharge test, the container is visually inspected to check for any silt.

[0189] “○”: There was no silt in the container after the discharge test.

[0190] "×": There is silt in the container after the discharge test.

[0191] (3) Results of the discharge test

[0192] (3-1) Whether there is discharge

[0193] In Table 1, “None” for “Refrigerant / Refrigeration Oil” indicates the discharge results of a comparative example that contains refrigerant but does not use refrigeration oil.

[0194] [Table 1]

[0195]

[0196] (3-2) Hue Evaluation

[0197] [Table 2]

[0198]

[0199] (3-3) Presence or absence of silt

[0200] [Table 3]

[0201]

[0202] The results of the discharge test show that in compositions containing refrigerant and refrigeration oil, discharge can be suppressed by coexisting refrigeration oil with a contact angle of 0.1°≤Θ≤90° with the substrate in refrigerants such as HFO-1132(E / Z), HFO-1132a, HFO-1123, and FO-1114. Based on these results, it can be evaluated that by combining the refrigerant with specific refrigeration oils in the composition, refrigerant disproportionation is suppressed, and the refrigerant exhibits excellent stability.

[0203] On the other hand, in the absence of refrigeration oil (the comparative example marked "None" in Table 1), discharge occurred in the refrigeration oil during the discharge test.

[0204] Therefore, the composition of the present invention containing refrigerant and refrigeration oil suppresses refrigerant disproportionation and exhibits excellent refrigerant stability, thus enabling the suppression of discharge in thermal cycling systems.

Claims

1. A heat cycle system characterized in that: the heat cycle system uses a composition containing a refrigerant and a refrigeration oil, the heat cycle system has a compression mechanism having a contact portion which is in contact with the composition for the heat cycle system of the compression mechanism, the contact portion is made of at least one engineering plastic selected from the group consisting of a polyamide resin, a polyphenylene sulfide resin, a polyacetal resin, a polybutylene terephthalate resin, and a fluorine resin, the composition contains 40 mass% or more of the refrigerant selected from at least one refrigerant among monofluoroethylene (HFO-1141), trans-1,2-difluoroethylene (HFO-1132(E)), cis-1,2-difluoroethylene (HFO-1132(Z)), 1,1-difluoroethylene (HFO-1132a), and tetrafluoroethylene (FO-1114) with respect to the entire composition, and the contact angle of the refrigeration oil with a base material made of the engineering plastic is 0.1° < Θ < 90°.

2. The heat cycle system according to claim 1, characterized in that: the refrigeration oil has an insulation breakdown voltage of 10 kV or more.

3. The heat cycle system according to claim 1 or 2, characterized in that: the refrigeration oil is at least one selected from the group consisting of a polyalkylene glycol (PAG), a polyol ester (POE), and a polyvinyl ether (PVE).

4. The heat cycle system according to claim 1 or 2, characterized in that: the composition is used as a refrigeration oil-containing working fluid.

5. The heat cycle system according to claim 1 or 2, characterized in that: the heat cycle system is at least one selected from the group consisting of a freezing / refrigerating apparatus, an air conditioning apparatus, a power generation system, a heat transport device, and a secondary cooling machine.

6. A method for suppressing disproportionation of a refrigerant using a refrigeration oil, characterized in that: a composition containing a refrigerant and a refrigeration oil contains 40 mass% or more of the refrigerant selected from at least one refrigerant among monofluoroethylene (HFO-1141), trans-1,2-difluoroethylene (HFO-1132(E)), cis-1,2-difluoroethylene (HFO-1132(Z)), 1,1-difluoroethylene (HFO-1132a), and tetrafluoroethylene (FO-1114) with respect to the entire composition, and the contact angle of the refrigeration oil with a base material made of at least one engineering plastic selected from the group consisting of a polyamide resin, a polyphenylene sulfide resin, a polyacetal resin, a polybutylene terephthalate resin, and a fluorine resin is 0.1° < Θ < 90°.

7. The method according to claim 6, characterized in that: the refrigeration oil has an insulation breakdown voltage of 10 kV or more.

8. The method according to claim 6 or 7, characterized in that: the refrigeration oil is at least one selected from the group consisting of a polyalkylene glycol (PAG), a polyol ester (POE), and a polyvinyl ether (PVE).

9. A composition containing a refrigerant and a refrigeration oil, characterized in that: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ The refrigerant is at least one refrigerant selected from the group consisting of monofluoroethylene (HFO-1141), trans-1,2-difluoroethylene (HFO-1132(E)), cis-1,2-difluoroethylene (HFO-1132(Z)), 1,1-difluoroethylene (HFO-1132a), and tetrafluoroethylene (FO-1114) and contained in an amount of 40% by mass or more relative to the entire composition, The contact angle of the refrigerant oil with a base material composed of at least one engineering plastic selected from the group consisting of a polyamide resin, a polyphenylene sulfide resin, a polyacetal resin, a polybutylene terephthalate resin, and a fluororesin is 0.1°≤Θ≤90°.

10. The composition according to claim 9, wherein: The insulation breakdown voltage of the refrigerant oil is 10 kV or more.

11. The composition according to claim 9 or 10, wherein: The refrigerant oil is at least one selected from the group consisting of a polyalkylene glycol (PAG), a polyol ester (POE), and a polyvinyl ether (PVE).

12. The composition according to claim 9 or 10, wherein: The composition is used as a working fluid containing a refrigerant oil.

13. The composition according to claim 9 or 10, wherein: The composition is used in a heat cycle system.

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