Refrigerant oil and heat pumps containing it

Abstract

To provide a refrigerant oil with improved chemical stability at high temperatures and / or high pressures, and a heat pump containing the same. [Solution] The refrigerant oil according to an exemplary embodiment of the present disclosure comprises a silane compound comprising at least one of a glycidyl group or an isocyanate group. The heat pump according to an exemplary embodiment of the present disclosure comprises a refrigerant comprising trifluoroiodomethane (R-13I1) and the refrigerant oil.

Description

[Technical Field]

[0001] This disclosure relates to refrigerant oil and heat pumps containing the same. [Background technology]

[0002] In recent years, 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 smaller heat pumps. A heat pump is equipped with a refrigerant circulation system that includes a compressor, condenser, expansion device, and evaporator. The refrigerant circulation system utilizes the phenomenon that liquids absorb heat from their surroundings when they vaporize, and a cycle is repeated that includes compression and heating of the vaporized refrigerant in the compressor, liquefaction of the refrigerant through heat dissipation condensation in the condenser, depressurization and expansion in the expansion device, and vaporization of the refrigerant in the evaporator.

[0003] In addition to the refrigerant, the refrigerant circulation system is filled with refrigerant oil to lubricate the sliding parts of the compressor. The refrigerant oil is designed to provide the desired performance when filled into the refrigerant circulation system, and it is important to consider its compatibility with the refrigerant. For example, refrigerant oil with poor compatibility with the refrigerant may not return to the sliding parts of the compressor because it does not mix with the refrigerant when circulating within the refrigerant circulation system, which could lead to a deterioration in lubrication.

[0004] To better meet these performance requirements, refrigeration lubricants primarily composed of oxygen-containing organic compounds such as vinyl ether compounds and polyoxyalkylene glycols are commonly used in the case of HFC refrigerants. To further improve the stability and lubrication performance of refrigeration lubricants, various additives are usually added to refrigeration lubricants primarily composed of oxygen-containing organic compounds. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Korean Published Patent No. 2010-0017092 [Overview of the project] [Problems that the invention aims to solve]

[0006] One of the objectives of this disclosure is to provide a refrigerant oil with improved chemical stability at high temperatures and / or high pressures.

[0007] One of the issues addressed by this disclosure is to provide a heat pump containing refrigerant oil with improved chemical stability at high temperatures and / or high pressures. [Means for solving the problem]

[0008] The refrigeration oil according to exemplary embodiments of the present disclosure comprises a silane compound comprising at least one of a glycidyl group or an isocyanate group.

[0009] In exemplary embodiments, the silane compound containing the glycidyl group may include a silane compound represented by the following chemical formula 1.

[0010] [ka]

[0011] In chemical formula 1, R 1 ~R 3 Each of these is an organic group with 1 to 10 carbon atoms, and R 4 This may be an organic group having 1 to 10 carbon atoms.

[0012] In an exemplary embodiment, the R 1 ~R 3 Each of these may independently be an alkyl group or alkoxy group having 1 to 10 carbon atoms.

[0013] In exemplary embodiments, the silane compound containing the isocyanate group may include a silane compound represented by the following chemical formula 2.

[0014] [Chemical formula]

[0015] In Chemical formula 2, R 5 ~R 7 are each independently an organic group having 1 to 10 carbon atoms, and R 8 may be an alkylene group having 1 to 10 carbon atoms.

[0016] In an exemplary embodiment, the R 5 ~R 7 may each independently be an alkyl group or an alkoxy group having 1 to 10 carbon atoms.

[0017] In an exemplary embodiment, the refrigeration oil may further contain a stabilizer containing a phosphate compound.

[0018] In an exemplary embodiment, the stabilizer may include trimethyl phosphate, triethyl phosphate, tributyl phosphate, tris(methylphenyl) phosphate, triphenyl phosphate, and the like.

[0019] In an exemplary embodiment, the refrigeration oil may further contain a lubricant.

[0020] In an exemplary embodiment, the lubricant may include a polyol ester.

[0021] The heat pump according to an exemplary embodiment of the present disclosure includes a refrigerant containing trifluoroiodomethane (R-13I1) and the refrigeration oil. [Advantages of the Invention]

[0022] Refrigerant oils according to exemplary embodiments of the present disclosure can improve chemical stability at high temperatures and / or high pressures.

[0023] The heat pumps according to exemplary embodiments of this disclosure can improve chemical stability at high temperatures and / or high pressures.

[0024] The refrigerant oil disclosed herein can be used in environmentally friendly heat pumps and other applications that use a refrigerant containing trifluoroiodomethane (R-13I1) to reduce air pollution and greenhouse gas emissions and prevent climate change. [Brief explanation of the drawing]

[0025] [Figure 1] Figure 1 is a schematic diagram illustrating the flow of refrigerant for heat exchange in the cooling mode of a heat exchanger according to one embodiment. [Figure 2] Figure 2 is a schematic diagram illustrating the flow of refrigerant for heat exchange in the heating mode of a heat exchanger according to one embodiment. [Figure 3] Figure 3 is a photograph showing the results of the ASHRAE 97 evaluation performed on the refrigeration oil of Example 1 in the experimental example. [Figure 4] Figure 4 is a photograph showing the results of the ASHRAE 97 evaluation performed on the refrigerant oil of Example 2 in the experimental example. [Figure 5] Figure 5 is a photograph showing the results of the ASHRAE 97 evaluation performed on the refrigerant oil of Example 4 in the experimental example. [Figure 6] Figure 6 is a photograph showing the results of the ASHRAE 97 evaluation performed on the refrigeration oil of Comparative Example 1 in the experimental example. [Figure 7] Figure 7 is a photograph showing the results of the ASHRAE 97 evaluation performed on the refrigeration oil of Comparative Example 2 in the experimental example. [Figure 8]Figure 8 is a photograph showing the results of the ASHRAE 97 evaluation performed on the refrigeration oil of Comparative Example 3 in the experimental example. [Modes for carrying out the invention]

[0026] According to embodiments of this disclosure, a refrigeration oil containing a silane compound is provided.

[0027] The inclusion of a silane compound in the refrigerant oil can improve the chemical stability of the refrigerant at high temperatures and / or high pressures.

[0028] The following describes the present disclosure in detail. However, these are illustrative examples and the present disclosure is not limited to the specific embodiments described illustratively.

[0029] As used in this disclosure, the term “organic group” may consist only of carbon and hydrogen, or it may further consist of one or more heteroatoms and substituents containing carbon and hydrogen.

[0030] As used in this disclosure, the term “heteroatom” may refer to an atom other than carbon and / or hydrogen. For example, such heteroatoms may be nitrogen (N), oxygen (O), phosphorus (P), sulfur (S), and the like.

[0031] As used in this disclosure, the term "substituted" may mean that at least one hydrogen atom of a compound is substituted with a substituent such as a halogen group, a hydroxyl group, a heteroalkyl group, a heterocycloalkyl group, a heteroaryl group, an amine group, a nitrile group, a nitro group, or a silyl group.

[0032] As used in this disclosure, the term "unsubstituted" may mean that not all hydrogen atoms in a compound are substituted.

[0033] As used in this disclosure, the term “alkyl group” may mean a linear or branched alkyl group having 1 to 10 carbon atoms, unless otherwise defined in that portion.

[0034] As used in this disclosure, the term "cycloalkyl group" may mean a functional group obtained by removing one hydrogen atom from a cycloalkane having 1 to 10 carbon atoms, unless otherwise defined in the relevant portion.

[0035] As used in this disclosure, the term "aryl group" may mean a functional group obtained by removing one hydrogen atom from an aromatic hydrocarbon having 6 to 10 carbon atoms, unless otherwise defined in the relevant portion.

[0036] As used in this disclosure, the term "alkylene group" may mean, unless otherwise defined in the relevant portion, a functional group obtained by removing two hydrogen atoms from a linear or branched alkyl group having 1 to 10 carbon atoms.

[0037] The refrigeration oil according to exemplary embodiments of the present disclosure comprises a silane compound comprising at least one of a glycidyl group or an isocyanate group.

[0038] In exemplary embodiments, silane compounds can act as acid scavengers. They can also further function as water scavengers. Refrigerant oil can be used with refrigerants in heat exchange systems (e.g., heat pumps), and silane compounds can function to remove acids generated by the decomposition of the refrigerant during system operation. The inclusion of silane compounds in the refrigerant oil can improve its chemical stability at high temperatures and / or high pressures.

[0039] In this disclosure, the acid-scavenging and water-scavenging capabilities of the silane compound can be further improved by including a glycidyl group as a functional group.

[0040] In this disclosure, the acid-scavenging ability and water-scavenging ability can be further improved by including an isocyanate group as a functional group in the silane compound.

[0041] In exemplary embodiments, the refrigeration oil can be used with a refrigerant containing trifluoroiodomethane (R-13I1). Trifluoroiodomethane (R-13I1) is a type of hydrofluorocarbon (HFC) refrigerant with an ozone depletion potential (ODP) of 0 and a global warming potential (GWP) of less than 5. Therefore, including trifluoroiodomethane (R-13I1) in the refrigerant can improve environmental compatibility.

[0042] Trifluoroiodomethane (R-13I1) can react with water to produce acid due to its reactivity. This can lead to discoloration of the refrigerant or refrigeration oil due to oxidation, sludge formation, and metal corrosion. Furthermore, the production of the acid may accelerate the decomposition of trifluoroiodomethane (R-13I1). In this disclosure, the refrigeration oil of the embodiment contains a silane compound as an acid scavenger, thereby removing the acid generated by the decomposition of the refrigerant.

[0043] In exemplary embodiments, the silane compound may be present in an amount of 5% by weight or less, or 0.1% to 5% by weight, or 1% to 5% by weight, or 1% to 3% by weight, or 1% to 2% by weight, relative to the total weight of the refrigerant oil. When the silane compound is present in an amount of 5% by weight or less relative to the total weight of the refrigerant oil, it is possible to prevent a decrease in the lubrication performance of the refrigerant oil. Furthermore, it is possible to further improve the chemical stability of trifluoroiodomethane (R-13I1), such as by preventing iodine contained in the refrigerant trifluoroiodomethane (R-13I1) from adhering to metal surfaces.

[0044] In exemplary embodiments, the silane compound containing the glycidyl group may include a silane compound represented by the following chemical formula 1.

[0045] [ka]

[0046] In chemical formula 1, R 1 ~R 3 Each of these may 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.

[0047] For example, R 1 ~R 3 Each of these may independently be an alkyl or alkoxy group having 1 to 10 carbon atoms; or an alkyl or alkoxy group having 1 to 8 carbon atoms; or an alkyl or alkoxy group having 1 to 5 carbon atoms.

[0048] In chemical formula 1, R 4 This may 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.

[0049] For example, R 4 This may be an alkylene group having 1 to 10 carbon atoms containing at least one heteroatom, or an alkylene group having 1 to 8 carbon atoms, or an alkylene group having 1 to 5 carbon atoms.

[0050] In exemplary embodiments, the silane compound containing the glycidyl group may include 3-(Glycidyloxypropyl)trimethoxysilane. The 3-(Glycidyloxypropyl)trimethoxysilane can be represented by the following chemical formula 1-1.

[0051] [ka]

[0052] In exemplary embodiments, the silane compound containing the isocyanate group may include a silane compound represented by the following chemical formula 2.

[0053] [ka]

[0054] In chemical formula 2, R 5 ~R 7 Each of these may 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.

[0055] For example, R 5 ~R 7 Each of these may independently be an alkyl or alkoxy group having 1 to 10 carbon atoms; or an alkyl or alkoxy group having 1 to 8 carbon atoms; or an alkyl or alkoxy group having 1 to 5 carbon atoms.

[0056] In chemical formula 2, R 8 This 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.

[0057] In exemplary embodiments, the silane compound containing the isocyanate group may include 3-Isocyanatopropyltrimethoxysilane. The 3-Isocyanatopropyltrimethoxysilane can be represented by the following chemical formula 2-1.

[0058] [ka]

[0059] In exemplary embodiments, the refrigerant oil may further contain a stabilizer. For example, the stabilizer may include thiazole compounds, triazole compounds, thiadiazole compounds, etc. For example, the stabilizer may include phosphate compounds. For example, the phosphate compounds may include trimethylphosphate, triethylphosphate, tributylphosphate, tris(methylphenyl)phosphate, triphenylphosphate, etc. This prevents the decomposition of the refrigerant and refrigerant oil, oxidation of the refrigerant oil, etc., and further improves the chemical stability of the refrigerant oil at high temperatures and / or high pressures.

[0060] The refrigeration oil may further contain amine-based phosphate compounds, particularly amine-based phosphate compounds having 10 or more carbon atoms. This can further improve chemical stability at high temperatures and / or high pressures.

[0061] The stabilizer may be present in an amount of 0.5% to 3% by weight, 0.5% to 2% by weight, or 1% to 2% by weight relative to the total weight of the refrigerant oil. When the refrigerant oil contains the stabilizer at 3% by weight or less, it is possible to prevent the initial total acid number (TAN) of the refrigerant oil from becoming excessively high, thereby further improving the chemical stability of the refrigerant oil.

[0062] In exemplary embodiments, the refrigeration oil may further contain a lubricant. For example, the lubricant may include paraffin, naphthenes, aromatic hydrocarbons, benzene or naphthalene substituted or unsubstituted with linear and branched alkyl groups, polyesters, polyol esters, polyvinyl ethers, and the like. For example, the lubricant may contain alkylated naphthalene. The alkylated naphthalene may be monoalkylnaphthalene, dialkylnaphthalene, trialkylnaphthalene, tetraalkylnaphthalene, or a mixture thereof.

[0063] For example, the lubricant may include a polyol ester.

[0064] The lubricant may be present in an amount of 70% to 99% by weight, or 80% to 98.5% by weight, or 90% to 98% by weight, or 91% to 97.5% by weight, relative to the total weight of the refrigeration oil.

[0065] The refrigerant oil according to exemplary embodiments may further include antioxidants, defoamers, load-bearing additives, chlorine scavengers, detergent dispersants, viscosity index improvers, oiliness agents, rust inhibitors, pour point depressants, extreme pressure additives, and the like.

[0066] For example, the antioxidant may be a phenolic or amine-based 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 amine-based antioxidant may be N,N'-diisopropyl-p-phenylenediamine, N,N'-di-sec-butyl-p-phenylenediamine, phenyl-α-naphthylamine, N,N'-diphenyl-p-phenylenediamine, or the like.

[0067] For example, the defoaming agent may be a monopolymer or copolymer of acrylic esters.

[0068] 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, or an extreme pressure additive of a metal compound. The organosulfur compound extreme pressure additive may be a monosulfide, polysulfide, sulfoxide, sulfone, thiosulfinate, sulfurized oil, thiocarbonate, thiophene, thiazole, 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 organochlorine-based extreme pressure additive may be a chlorinated hydrocarbon or a chlorinated carboxylic acid derivative, etc. The organofluorine-based extreme pressure additive may be a fluorinated aliphatic carboxylic acid, fluoroethylene resin, fluoroalkyl polysiloxane, fluorinated graphite, etc. The extreme pressure additive of the metal compound may be naphthenate (such as lead naphthenate), fatty acid salt (such as lead fatty acid salt), thiophosphate (such as zinc dialkyldithiophosphate), thiocarbamate, organomolybdenum compound, organotin compound, or organogermanium compound.

[0069] Figures 1 and 2 are schematic diagrams illustrating the flow of refrigerant for heat exchange in the cooling mode or heating mode of a heat exchanger according to one embodiment, respectively.

[0070] The arrows in Figures 1 and 2 indicate the direction of the refrigerant flow.

[0071] Referring to Figure 1, in cooling mode, the refrigerant is compressed by the compressor, bypasses the internal condenser and expansion valve (heating) in sequence, releases heat in the external condenser, then expands in the expansion valve (cooling), and reabsorbs heat through the evaporator.

[0072] Referring to Figure 2, in heating mode, the refrigerant is compressed by the compressor, releases heat in the internal condenser, expands in the expansion valve (heating), absorbs heat in the external condenser, and then absorbs additional heat through the cooler.

[0073] A heat pump according to an exemplary embodiment of the present disclosure comprises a refrigerant containing trifluoroiodomethane (R-13I1) and a refrigeration oil. This may improve the environmental compatibility and stability of the heat pump and enhance its refrigeration performance.

[0074] The heat pump may include a compressor, a condenser, an expansion valve, and an evaporator. In the compressor, the aforementioned refrigerant is compressed to a high temperature and high pressure state, and in the expansion valve, the aforementioned refrigerant can expand to a low temperature and low pressure state.

[0075] For example, the aforementioned refrigerant can release or absorb heat while circulating within the heat pump through a compressor, condenser, expansion valve, and evaporator. The refrigerant may be maintained in a high-temperature and high-pressure gaseous state in the compressor. The refrigerant may liquefy into a liquid state by releasing heat in the condenser. The refrigerant may be maintained in a low-temperature and low-pressure liquid state, or a mixture of liquid and gas, in the expansion valve. The refrigerant may vaporize into a gaseous state by absorbing heat in the evaporator.

[0076] 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.

[0077] Using the aforementioned refrigerant, a highly efficient heat pump having a coefficient of performance within the aforementioned range can be provided.

[0078] According to exemplary embodiments, the refrigerant containing trifluoroiodomethane (R-13I1) may further include natural refrigerants, hydrofluorocarbon (HFC) refrigerants, hydrofluoroolefin (HFO) refrigerants, hydrochlorofluorocarbon (HCFC) refrigerants, and the like.

[0079] The aforementioned natural refrigerant 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, and the like.

[0080] The aforementioned 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), and octafluoropropane (R- This may include 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), 1,1,1,3,3-pentafluoropropane (R-245fa), octafluorocyclobutane (RC318), 1,1,1,3,3-pentafluorobutane (R-365mfc), etc.

[0081] The aforementioned hydrofluoroolefin (HFO) refrigerants 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), and the like.

[0082] The aforementioned hydrochlorofluorocarbon (HCFC) refrigerants may include difluorochloromethane (R-22), chlorotetrafluoroethane (R-124), 1-chloro-1,1-difluoroethane (R-142b), and the like.

[0083] Examples are provided below to aid in understanding this disclosure. These examples are merely illustrative and do not limit the scope of the attached claims. It will be apparent to those skilled in the art that various changes and modifications to the examples are possible within the scope of this disclosure and the technical concept, and that such changes and modifications naturally fall within the scope of the attached claims.

[0084] Examples and Comparative Examples The refrigerant oils for the examples and comparative examples were prepared with the compositions shown in Table 1 below.

[0085] [Table 1]

[0086] Experimental example: Evaluation of ASHRAE 97 The refrigerant oil, CF3I, copper (Cu) catalyst, aluminum (Al) catalyst, and iron (Fe) catalyst used in the example were placed in a sealed tube and exposed to a 175°C environment for 14 days, after which the following evaluations were performed. In the case of Comparative Example 1, the evaluation was performed under the same conditions as in the above example, except that it was exposed to an environment of 150°C. In the case of Comparative Example 2 and Comparative Example 3, the evaluations were performed under the same conditions as in the above-mentioned examples, except that they were exposed to an environment of 160°C.

[0087] 1) Measurement of Total Acid Number (TAN) The TAN was measured using a 686 Titroprocessor (manufactured by Metrohm) according to the ASTM D664 method.

[0088] 2) Measurement of ASTM color The color was measured using a LICO 500 spectrophotometer (HACH LANGE) according to the ASTM D1500 method.

[0089] Figures 3 to 8 are photographs showing the results of the ASHRAE 97 evaluation performed in the experimental examples for the refrigeration oils of Example 1, Example 2, Example 4, and Comparative Examples 1 to 3, respectively.

[0090] The evaluation results of the experimental examples for refrigeration oil in Examples 1 to 6 and Comparative Examples 1 to 3 are shown in Table 2 below.

[0091] [Table 2]

[0092] Referring to Figures 3 to 8, the refrigerant oils of Examples 1, 2, and 4 showed less color change even in higher temperatures (175°C), and exhibited better chemical stability at high temperatures compared to the comparative example refrigerant oil.

[0093] Referring to Table 2, in the case of the refrigerant oil in the example exposed to a higher temperature (175°C), the TAN value was 1.3 or less, while in the case of the refrigerant oil in the comparative example exposed to a lower temperature (150°C), the TAN value was 5 or more, indicating that the acid scavenging ability of the refrigerant oil in the example containing the silane compound was better.

[0094] In the case of the refrigeration oil in the example, the ASTM color was 2 or less, whereas in the case of the refrigeration oil in the comparative example, the ASTM color was 6 or more.

[0095] Therefore, the examples in which silane compounds were used as acid scavengers showed better chemical stability at high temperatures.

Claims

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

2. The refrigerant oil according to claim 1, wherein the silane compound containing the glycidyl group includes a silane compound represented by the following chemical formula 1. 【Chemistry 1】 (In chemical formula 1, R １ ~R ３ Each of these is an organic group having 1 to 10 carbon atoms, and R ４ (This refers to an organic group with 1 to 10 carbon atoms.)

3. The aforementioned R １ ~R ３ The refrigerating oil according to claim 2, wherein each is independently an alkyl group or alkoxy group having 1 to 10 carbon atoms.

4. The refrigerant oil according to claim 1, wherein the silane compound containing the isocyanate group includes a silane compound represented by the following chemical formula 2. 【Chemistry 2】 (In chemical formula 2, R ５ ~R ７ Each of these is an organic group having 1 to 10 carbon atoms, and R ８ (This refers to an alkylene group having 1 to 10 carbon atoms.)

5. Said R ５ ~R ７ The refrigeration oil according to claim 4, wherein each of them is independently an alkyl group or an alkoxy group having 1 to 10 carbon atoms.

6. The refrigerant oil according to claim 1, further comprising a stabilizer containing a phosphate compound.

7. The refrigerant oil according to claim 6, wherein the stabilizer comprises at least one of trimethyl phosphate, triethyl phosphate, tributyl phosphate, tris(methylphenyl) phosphate, and triphenyl phosphate.

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

9. The refrigeration oil according to claim 8, wherein the lubricant comprises a polyol ester.

10. A refrigerant containing trifluoroiodomethane (R-13I1), A heat pump comprising the refrigerant oil described in claim 1.

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