Refrigeration oil and heat pump comprising same

Abstract

A refrigeration oil according to exemplary embodiments of the present disclosure comprises a silane compound containing at least one of a glycidyl group or an isocyanate group. A heat pump according to exemplary embodiments of the present disclosure comprises a refrigerant including trifluoroiodomethane (R-131I1) and the refrigeration oil.

Description

Refrigerant oil and heat pump containing the same

[0001] The present disclosure relates to refrigerant oil and a heat pump including the same.

[0002]

[0003] Recently, the types of heat pumps used indoors and outdoors have diversified, and the development of electric vehicles and other technologies has led to a demand for miniaturized heat pumps. Heat pumps are equipped with a refrigerant circulation system that includes a compressor, condenser, expansion device, and evaporator. A refrigerant circulation system utilizes the phenomenon of heat being taken from the surroundings when a liquid vaporizes. The cycle repeats, including compression and temperature increase of the vaporized refrigerant in the compressor, liquefaction of the refrigerant through heat-radiating condensation in the condenser, depressurization and expansion in the expansion device, and vaporization of the refrigerant in the evaporator.

[0004] In addition to refrigerant, the refrigerant circulation system is filled with refrigerant oil to lubricate the compressor's sliding parts. Refrigerant oil is designed to achieve the desired performance when charged to the refrigerant circulation system. However, compatibility with the refrigerant becomes crucial. For example, refrigerant oil with poor compatibility with the refrigerant may not be compatible with the refrigerant when circulated within the refrigerant circulation system, potentially preventing it from reaching the compressor's sliding parts, leading to concerns about deterioration in lubrication.

[0005] To better meet these performance requirements, refrigerating lubricants primarily composed of oxygen-containing organic compounds, such as vinyl ether compounds and polyoxyalkylene glycols, are commonly used for HFC refrigerants. To further enhance the stability and lubricating performance of refrigerating lubricants primarily composed of oxygen-containing organic compounds, various additives are typically added.

[0006]

[0007] An object of the present disclosure is to provide a refrigerant oil having improved chemical stability at high temperatures and / or high pressures.

[0008] One object of the present disclosure is to provide a heat pump including a refrigerant oil having improved chemical stability at high temperatures and / or high pressures.

[0009]

[0010] Refrigerating oil according to exemplary embodiments of the present disclosure comprises a silane compound including at least one of a glycidyl group and an isocyanate group.

[0011] In exemplary embodiments, the silane compound including the glycidyl group may include a silane compound represented by the following chemical formula 1.

[0012] [Chemical Formula 1]

[0013]

[0014] In chemical formula 1, R 1 Inland R 3 Each independently represents an organic group having 1 to 10 carbon atoms, R 4 may be an organic group having 1 to 10 carbon atoms.

[0015] In exemplary embodiments, the R 1 Inland R 3 Each may independently be an alkyl group or an alkoxy group having 1 to 10 carbon atoms.

[0016] In exemplary embodiments, the silane compound including the isocyanate group may include a silane compound represented by the following chemical formula 2.

[0017] [Chemical Formula 2]

[0018]

[0019] In chemical formula 2, R 5 Inland R 7 Each independently represents an organic group having 1 to 10 carbon atoms, R8 It may be an alkylene group having 1 to 10 carbon atoms.

[0020] In exemplary embodiments, the R 5 Inland R 7 Each may independently be an alkyl group or an alkoxy group having 1 to 10 carbon atoms.

[0021] In exemplary embodiments, the refrigerant oil may further include a stabilizer comprising a phosphate compound.

[0022] In exemplary embodiments, the stabilizer may include trimethylphosphate, triethylphosphate, tributylphosphate, tris(methylphenyl)phosphate, triphenylphosphate, and the like.

[0023] In exemplary embodiments, the refrigerant oil may further include a lubricant.

[0024] In exemplary embodiments, the lubricant may comprise a polyol ester.

[0025] A heat pump according to exemplary embodiments of the present disclosure includes a refrigerant comprising trifluoroiodomethane (R-13I1) and the refrigerating oil.

[0026]

[0027] Refrigerating oil according to exemplary embodiments of the present disclosure may have improved chemical stability at high temperatures and / or high pressures.

[0028] Heat pumps according to exemplary embodiments of the present disclosure may have improved chemical stability at high temperatures and / or high pressures.

[0029] The refrigerant oil of the present disclosure can be used in eco-friendly heat pumps and the like that use a refrigerant including trifluoroiodomethane (R-13I1) to suppress air pollution and greenhouse gas emissions and prevent climate change.

[0030]

[0031] Figures 1 and 2 are schematic diagrams showing the flow of refrigerant for heat exchange in a cooling mode or a heating mode of a heat exchanger according to one embodiment, respectively.

[0032] Figures 3 to 8 are photographs showing ASHRAE 97 evaluations of experimental examples performed on refrigerating oils of Examples 1, 2, 4, and Comparative Examples 1 to 3, respectively.

[0033]

[0034] According to embodiments of the present disclosure, a refrigerant oil comprising a silane compound is provided.

[0035] As the above refrigerant oil contains a silane compound, the chemical stability of the refrigerant at high temperature and / or high pressure can be improved.

[0036] Below, the present disclosure will be described in detail. However, this is merely exemplary and the present disclosure is not limited to the specific embodiments described as examples.

[0037] The term "organic group" as used herein may be a substituent containing only carbon and hydrogen, or containing one or more heteroatoms and containing carbon and hydrogen.

[0038] The term "heteroatom" as used herein may be an atom other than carbon and / or hydrogen. For example, the heteroatom may be nitrogen (N), oxygen (O), phosphorus (P), sulfur (S), etc.

[0039] The term "substituted" as used in the present disclosure may mean that at least one of the hydrogen atoms of the compound is substituted with a substituent such as a halogen group, a hydroxy group, a heteroalkyl group, a heterocycloalkyl group, a heteroaryl group, an amine group, a nitrile group, a nitro group, or a silyl group.

[0040] The term “unsubstituted” as used herein may mean that all hydrogen atoms of a compound are unsubstituted.

[0041] The term “alkyl group” as used in this disclosure may mean a straight or branched chain alkyl group having 1 to 10 carbon atoms, unless otherwise defined in the relevant part.

[0042] The term "cycloalkyl group" as used in this disclosure may mean a functional group in which one hydrogen atom is removed from a cycloalkane having 1 to 10 carbon atoms, unless otherwise defined in the relevant part.

[0043] The term "aryl group" used in the present disclosure may mean a functional group in which one hydrogen atom is removed from an aromatic hydrocarbon having 6 to 10 carbon atoms, unless otherwise defined in the relevant part.

[0044] The term "alkylene group" used in this disclosure may mean a functional group in which two hydrogen atoms are removed from a straight or branched alkyl group having 1 to 10 carbon atoms, unless otherwise defined in the relevant part.

[0045] Refrigerating oil according to exemplary embodiments of the present disclosure comprises a silane compound including at least one of a glycidyl group and an isocyanate group.

[0046] In exemplary embodiments, the silane compound may act as an acid scavenger. Additionally, it may also act as a moisture scavenger. Refrigerant oil may be used with a refrigerant in a heat exchange system (e.g., a heat pump), and the silane compound may function to remove acids generated by the decomposition of the refrigerant during system operation. By including the silane compound in the refrigerant oil, its chemical stability at high temperatures and / or high pressures may be improved.

[0047] In the present disclosure, since the silane compound includes a glycidyl group as a functional group, the acid-capturing ability and moisture-capturing ability can be further improved.

[0048] In the present disclosure, since the silane compound includes an isocyanate group as a functional group, the acid-capturing ability and moisture-capturing ability can be further improved.

[0049] In exemplary embodiments, the refrigerant oil may be used with a refrigerant including trifluoroiodomethane (R-13I1). Trifluoroiodomethane (R-13I1) is a type of hydrofluorocarbon (HFC) refrigerant, has an ozone depletion potential (ODP) of 0, and a global warming potential (GWP) of less than 5. Accordingly, by including trifluoroiodomethane (R-13I1) in the refrigerant, environmental friendliness may be improved.

[0050] Due to its reactivity, trifluoroiodomethane (R-13I1) can react with moisture to produce acid. This can result in discoloration of refrigerant or refrigerant oil, sludge formation, and metal corrosion due to oxidation of the refrigerant or refrigerant oil. Furthermore, the production of the acid can accelerate the decomposition of trifluoroiodomethane (R-13I1). In the present disclosure, the refrigerant oil of the embodiments includes a silane compound as an acid scavenger, thereby removing the acid produced by the decomposition of the refrigerant.

[0051] In exemplary embodiments, the silane compound may be present in an amount of 5 wt% or less, or 0.1 wt% to 5 wt%, or 1 wt% to 5 wt%, or 1 wt% to 3 wt%, or 1 wt% to 2 wt% of the total weight of the refrigerating oil. When the silane compound is present in an amount of 5 wt% or less of the total weight of the refrigerating oil, the lubricating performance of the refrigerating oil may be prevented from deteriorating. In addition, the chemical stability of trifluoroiodomethane (R-13I1), which is a refrigerant, may be further improved, such as by preventing iodine contained in the refrigerant trifluoroiodomethane (R-13I1) from attaching to a metal surface.

[0052] In exemplary embodiments, the silane compound including the glycidyl group may include a silane compound represented by the following chemical formula 1.

[0053] [Chemical Formula 1]

[0054]

[0055] In chemical formula 1, R 1 Inland R 3 Each of them can independently be an organic group having 1 to 10 carbon atoms, an organic group having 1 to 8 carbon atoms, or an organic group having 1 to 5 carbon atoms.

[0056] For example, R 1 Inland R 3Each independently may be an alkyl group or alkoxy group having 1 to 10 carbon atoms; or an alkyl group or alkoxy group having 1 to 8 carbon atoms; or an alkyl group or alkoxy group having 1 to 5 carbon atoms.

[0057] In chemical formula 1, R 4 It can be an organic group having 1 to 10 carbon atoms, or an organic group having 1 to 8 carbon atoms, or an organic group having 1 to 5 carbon atoms.

[0058] For example, R 4 may be an alkylene group having 1 to 10 carbon atoms, or an alkylene group having 1 to 8 carbon atoms, or an alkylene group having 1 to 5 carbon atoms, including at least one heteroatom.

[0059] In exemplary embodiments, the silane compound including the glycidyl group may include 3-(glycidyloxypropyl)trimethoxysilane. The 3-(glycidyloxypropyl)trimethoxysilane may be represented by the following chemical formula 1-1.

[0060] [Chemical Formula 1-1]

[0061]

[0062] In exemplary embodiments, the silane compound including the isocyanate group may include a silane compound represented by the following chemical formula 2.

[0063] [Chemical Formula 2]

[0064]

[0065] In chemical formula 2, R 5 Inland R 7 Each of them can independently be an organic group having 1 to 10 carbon atoms, an organic group having 1 to 8 carbon atoms, or an organic group having 1 to 5 carbon atoms.

[0066] For example, R 5 Inland R 7Each independently may be an alkyl group or alkoxy group having 1 to 10 carbon atoms; or an alkyl group or alkoxy group having 1 to 8 carbon atoms; or an alkyl group or alkoxy group having 1 to 5 carbon atoms.

[0067] In chemical formula 2, R 8 It may be an alkylene group having 1 to 10 carbon atoms, or an alkylene group having 1 to 8 carbon atoms, or an alkylene group having 1 to 5 carbon atoms.

[0068] In exemplary embodiments, the silane compound including the isocyanate group may include 3-isocyanatopropyltrimethoxysilane. The 3-isocyanatopropyltrimethoxysilane may be represented by the following chemical formula 2-1.

[0069] [Chemical Formula 2-1]

[0070]

[0071] In exemplary embodiments, the refrigerating oil may further include a stabilizer. For example, the stabilizer may include a thiazole-based compound, a triazole-based compound, a thiadiazole-based compound, etc. For example, the stabilizer may include a phosphate-based compound. For example, the phosphate-based compound may include trimethylphosphate, triethylphosphate, tributylphosphate, tris(methylphenyl)phosphate, triphenylphosphate, etc. Accordingly, the chemical stability of the refrigerating oil at high temperatures and / or high pressures may be further improved by preventing decomposition of the refrigerant and refrigerating oil, oxidation of the refrigerating oil, etc.

[0072] The above refrigerating oil may further include an amine phosphate compound, particularly an amine phosphate compound having 10 or more carbon atoms. Accordingly, chemical stability at high temperatures and / or high pressures may be further improved.

[0073] The stabilizer may be present in an amount of 0.5 wt% to 3 wt%, or 0.5 wt% to 2 wt%, or 1 wt% to 2 wt% of the total weight of the refrigerating oil. When the refrigerating oil contains the stabilizer in an amount of 3 wt% or less, the initial total acid number (TAN) of the refrigerating oil can be prevented from becoming excessively high, thereby further improving the chemical stability of the refrigerating oil.

[0074] In exemplary embodiments, the refrigerating oil may further include a lubricant. For example, the lubricant may include paraffin, naphthene, aromatic hydrocarbon, benzene or naphthalene substituted or unsubstituted with linear and branched alkyl groups, polyester, polyol ester, polyvinyl ether, and the like. For example, the lubricant may include alkylated naphthalene. The alkylated naphthalene may be monoalkyl naphthalene, dialkyl naphthalene, trialkyl naphthalene, tetraalkyl naphthalene, or a mixture thereof.

[0075] For example, the lubricant may comprise a polyol ester.

[0076] The lubricant may be from 70 wt% to 99 wt%, or from 80 wt% to 98.5 wt%, or from 90 wt% to 98 wt%, or from 91 wt% to 97.5 wt% of the total weight of the refrigerating oil.

[0077] Refrigerating oil according to exemplary embodiments may further include an antioxidant, an anti-foaming agent, a load-bearing additive, a chlorine scavenger, a detergent dispersant, a viscosity index improver, an oiliness agent, a rust inhibitor, a pour point depressant, an extreme pressure additive, and the like.

[0078] For example, the antioxidant may be a phenolic or amineic antioxidant. The phenolic antioxidant may be 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, etc. The above amine antioxidant may be N,N'-diisopropyl-p-phenylenediamine, N,N'-di-sec-butyl-p-phenylenediamine, phenyl-α-naphthylamine, N,N'-diphenyl-p-phenylenediamine, etc.

[0079] For example, the foaming agent may be a homopolymer or copolymer of acrylic ester.

[0080] For example, the extreme pressure additive may be an extreme pressure additive of an organosulfur compound, an extreme pressure additive of a phosphorothioate ester, an ester-based extreme pressure additive, an organochlorine-based extreme pressure additive, an organofluorine-based extreme pressure additive, an alcohol-based extreme pressure additive, an extreme pressure additive of a metal compound, etc. The extreme pressure additive of the organosulfur compound may be a monosulfide, a polysulfide, a sulfoxide, a sulfone, a thiosulfinate, a sulfurized oil, a thiocarbonate, a thiophene, a thiazole, a methanesulfonate, etc. The ester-based extreme pressure additive may be a higher fatty acid, a hydroxyaryl fatty acid, a polyol ester, an acrylate, etc. The extreme pressure additive of the organochlorine-based may be a chlorinated hydrocarbon or a chlorinated carboxylic acid derivative, etc. The above-mentioned organic fluorine-based extreme pressure additive may be a fluorinated aliphatic carboxylic acid, a fluoroethylene resin, a fluoroalkyl polysiloxane, a fluorinated graphite, etc. The above-mentioned extreme pressure additive of the metal compound may be a naphthenate (such as lead naphthenic acid), a fatty acid salt (such as lead fatty acid salt), a thiophosphate (such as zinc dialkyldithiophosphate), a thiocarbamate, an organic molybdenum compound, an organic tin compound, an organic germanium compound, etc.

[0081] Figures 1 and 2 are schematic diagrams showing the flow of refrigerant for heat exchange in a cooling mode or a heating mode of a heat exchanger according to one embodiment, respectively.

[0082] The direction of the arrows in Figures 1 and 2 is intended to indicate the flow of refrigerant.

[0083] Referring to Figure 1, in cooling mode, the refrigerant is compressed through the compressor, bypasses the internal condenser and expansion valve (heating) in sequence, releases heat from the external condenser, then expands in the expansion valve (cooling) and reabsorbs heat through the evaporator.

[0084] Referring to Figure 2, in heating mode, the refrigerant is compressed through the compressor, releases heat from the internal condenser, expands in the expansion valve (heating), absorbs heat from the external condenser, and then absorbs additional heat through the cooler.

[0085] A heat pump according to exemplary embodiments of the present disclosure includes a refrigerant comprising trifluoroiodomethane (R-13I1) and the refrigerating oil. Accordingly, the heat pump can have improved refrigeration performance while being environmentally friendly and stable.

[0086] The above heat pump may include a compressor, a condenser, an expansion valve, and an evaporator. In the compressor, the above-described refrigerant may be compressed to a high temperature and high pressure state, and in the expansion valve, the above-described refrigerant may be expanded to a low temperature and low pressure state.

[0087] For example, the refrigerant described above can release or absorb heat while circulating through a compressor, a condenser, an expansion valve, and an evaporator within the heat pump. The refrigerant can be maintained in a high-temperature and high-pressure gaseous state in the compressor. The refrigerant can be liquefied into a liquid state by releasing heat in the condenser. The refrigerant can be maintained in a low-temperature and low-pressure liquid, or a liquid and gas mixture state, in the expansion valve. The refrigerant can absorb heat in the evaporator and vaporize into a gaseous state.

[0088] In some embodiments, the coefficient of performance (COP) of the heat pump may be 1 to 10. The coefficient of performance (COP) refers to the ratio of the amount of heat effectively obtained to the amount of work input when operating the heat pump.

[0089] A high-efficiency heat pump having a performance coefficient within the above range can be provided using the above-described refrigerant.

[0090] According to exemplary embodiments, the refrigerant including trifluoroiodomethane (R-13I1) may further include a natural refrigerant, a hydrofluorocarbon (HFC) refrigerant, a hydrofluoroolefin (HFO) refrigerant, a hydrochlorofluorocarbon (HCFC) refrigerant, etc.

[0091] The above natural refrigerants may include methane (R-50), ammonia (R-717), carbon dioxide (R-744), ethane (R-170), propane (R-290), propylene (R-1270), isobutane (R-600a), dimethyl ether, isopentane, pentane, etc.

[0092] The above hydrofluorocarbon (HFC) refrigerants include difluoromethane (R-32), 1,1-difluoroethane (R-152a), pentafluoroethane (R-125), 1,1,1,2-tetrafluoroethane (R-134a), 1,1,1-trifluoroethane (R-143a), trifluoromethyl methyl ether (RE143a), trifluoromethane (R-23), fluoroethane (R-161), octafluoropropane (R-218), 1,1,1,2,3,3,3-heptafluoropropane (R-227ea), 1,1,1,2,3,3-hexafluoropropane (R-236ea), 1,1,1,3,3,3-hexafluoropropane (R-236fa), It may include 1,1,1,3,3-pentafluoropropane (R-245fa), octafluorocyclobutane (RC318), 1,1,1,3,3-pentafluorobutane (R-365mfc), etc.

[0093] The above hydrofluoroolefin (HFO) refrigerant may include 1,1,2-trifluoroethylene (R-1123), 1-chloro-2,3,3,3-tetrafluoropropene (R1224yd(Z)), 2,3,3,3-tetrafluoropropene (R-1234yf), 1,3,3,3-tetrafluoropropene (R-1234ze), 1,2,3,3-tetrafluoropropene (R-1234ye), 3,3,3-trifluoropropene (R-1243zf), 1,1-difluoroethylene (R-1132a), 1,2,3,3,3-pentafluoropropene (R-1225ye), etc.

[0094] The above hydrochlorofluorocarbon (HCFC) refrigerants may include difluorochloromethane (R-22), chlorotetrafluoroethane (R-124), 1-chloro-1,1-difluoroethane (R-142b), etc.

[0095] Hereinafter, examples are presented to help understand the present disclosure, but these examples are only illustrative of the present disclosure and do not limit the scope of the appended claims. It will be apparent to those skilled in the art that various changes and modifications to the examples are possible within the scope and technical idea of ​​the present disclosure, and it is also natural that such changes and modifications fall within the scope of the appended claims.

[0096] Examples and Comparative Examples

[0097] Refrigerating oils of examples and comparative examples were manufactured with the compositions described in Table 1 below.

[0098] Classification POE (wt%) Alkylated naphthalene (wt%) Acid scavenger Stabilizer (wt%) Ingredient content (wt%) Example 1952A11.51.5 Example 291.52A151.5 Example 389.52A171.5 Example 4952A21.51.5 Example 591.52A251.5 Example 689.52A271.5 Comparative Example 1100----Comparative Example 2952B1.51.5 Comparative Example 393.52B31.5

[0099] * POE: (Synastive ES 4068, BASF)

[0100] * alkylated naphthalene (Synesstic 5, Exxon mobil company)

[0101] * Phosphate: tris(methylphenyl) phosphate (RC 3661, Lanxess)

[0102] * A1: Silane compound represented by chemical formula 1-1

[0103] * A2: Silane compound represented by chemical formula 2-1

[0104] * B: 2-Ethylhexyl glycidyl ether (CAS 2461-15-6)

[0105]

[0106] Experimental Example: ASHRAE 97 Evaluation

[0107] After the refrigerating oil, CF3I, copper (Cu) catalyst, aluminum (Al) catalyst, and iron (Fe) catalyst of the examples were put into a sealed tube, the following evaluation was performed after exposure to an environment of 175°C for 14 days.

[0108] For Comparative Example 1, the following evaluation was performed under the same conditions as the above examples, except that it was exposed to an environment of 150°C.

[0109] For Comparative Examples 2 and 3, the following evaluations were performed under the same conditions as the above examples, except that they were exposed to an environment of 160°C.

[0110] 1) Measurement of Total Area Network (TAN)

[0111] TAN was measured using the ASTM D664 method using a 686 Titroprocessor (Metrohm).

[0112] 2) ASTM color measurement

[0113] LICO 500 - Color was measured using the ASTM D1500 method using a spectral colorimeter (HACH LANGE).

[0114] Figures 3 to 8 are photographs showing ASHRAE 97 evaluations of experimental examples performed on refrigerating oils of Examples 1, 2, 4, and Comparative Examples 1 to 3, respectively.

[0115] The evaluation results of the experimental examples for the refrigerating oils of Examples 1 to 6 and Comparative Examples 1 to 3 are shown in Table 2 below.

[0116] Refrigerator Oil ASHRAE 97, 14 days Temperature (℃) After evaluation TANASTM color Example 1 1750.47 < 0.5 Example 2 1750.48 < 0.5 Example 3 1750.51 (Metal discoloration & sediment occurrence) 1 Example 4 1750.8 5 1 Example 5 1750.96 1.5 Example 6 1751.21 (Metal discoloration) 2 Comparative Example 1 150 > 15 > 8 Comparative Example 2 1608.2 (Sediment occurrence) 7 Comparative Example 3 1605.38 (Metal discoloration) 6

[0117] Referring to FIGS. 3 to 8, the refrigeration oils of Examples 1, 2, and 4 showed less color change even in a higher temperature (175°C) environment, and thus had better chemical stability at high temperatures than the refrigeration oils of the comparative examples.

[0118] Referring to Table 2, the TAN value of the refrigerating oil of the examples exposed to a higher temperature (175°C) was 1.3 or less, whereas the TAN value of the refrigerating oil of the comparative examples exposed to a lower temperature (150°C) was 5 or more, indicating that the acid-capturing ability of the refrigerating oil of the examples containing silane compounds was better.

[0119] In the case of the refrigerating oil of the examples, the ASTM color was 2 or less, whereas in the case of the refrigerating oil of the comparative examples, the ASTM color was 6 or more.

[0120] Accordingly, the examples using silane compounds as acid scavengers had better chemical stability at high temperatures.

Claims

1. A refrigerating oil comprising a silane compound containing at least one of a glycidyl group and an isocyanate group.

2. In claim 1, the silane compound containing the glycidyl group is a refrigerating oil containing a silane compound represented by the following chemical formula 1: [Chemical Formula 1] (In chemical formula 1, R 1 Inland R 3 Each independently represents an organic group having 1 to 10 carbon atoms, R 4 is an organic group having 1 to 10 carbon atoms).

3. In claim 2, the R 1 Inland R 3 Refrigerating oil, each independently an alkyl group or alkoxy group having 1 to 10 carbon atoms.

4. In claim 1, the silane compound containing the isocyanate group is a refrigerating oil containing a silane compound represented by the following chemical formula 2: [Chemical Formula 2] (In chemical formula 2, R 5 Inland R 7 are each independently an organic group having 1 to 10 carbon atoms, and R 8 is an alkylene group having 1 to 10 carbon atoms).

5. In claim 4, the R 5 Inland R 7 Refrigerating oil, each independently an alkyl group or alkoxy group having 1 to 10 carbon atoms.

6. A refrigerating oil according to claim 1, further comprising a stabilizer comprising a phosphate compound.

7. A refrigerating oil according to claim 6, wherein the stabilizer comprises at least one of trimethylphosphate, triethylphosphate, tributylphosphate, tris(methylphenyl)phosphate, and triphenylphosphate.

8. Refrigerating oil according to claim 1, further comprising a lubricant.

9. In claim 8, the lubricant is a refrigerating oil comprising a polyol ester.

10. Refrigerants containing trifluoroiodomethane (R-13I1); and A heat pump comprising the refrigerant oil of claim 1.

Images