Refrigerant oil, refrigeration compositions, and heat pumps

Abstract

To provide a refrigeration oil with improved high-temperature stability, a refrigeration composition with improved heat transfer characteristics and high-temperature stability, and a heat pump with improved heat transfer characteristics and high-temperature stability. [Solution] The refrigeration oil according to the embodiment of the present disclosure contains a silane compound of the following chemical formula 1. In the chemical formula 1, one or any two of R1 to R4 are independently selected from alkoxy groups C1 to C5, and the remainder are independently selected from C1 to C5 14 It is an alkyl group. The composition for a refrigerator according to the embodiments of this disclosure includes the refrigerant oil and the refrigerant. The heat pump according to the embodiments of this disclosure includes the refrigerant oil. JPEG2026139607000009.jpg44170

Description

[Technical Field]

[0001] Embodiments of this application relate to refrigeration oil, refrigeration compositions, and heat pumps. [Background technology]

[0002] Air conditioning or refrigeration systems use working fluids such as refrigerants and refrigerant oil as materials for heat exchange. An air conditioning system refers to a system that adjusts and maintains a comfortable environment by controlling the temperature, humidity, and air composition of a room. Air conditioning or refrigeration systems can be applied to buildings, factories, houses, vehicles, aircraft, and more.

[0003] Refrigerant oil circulates within the aforementioned system, contributing to the lubrication, cooling, sealing, and cleaning of mechanical components such as compressors, as well as regulating the solubility of the refrigerant. In some sections, it may even circulate together with the refrigerant.

[0004] Examples of refrigerants include fluorocarbon compounds, and ongoing research and development is being conducted to improve their stability in working fluids. [Overview of the project] [Problems that the invention aims to solve]

[0005] One of the objectives of this disclosure is to provide a refrigeration oil with improved high-temperature stability.

[0006] One objective of this disclosure is to provide a composition for refrigerators that has improved heat transfer characteristics and high-temperature stability.

[0007] One of the objectives of this disclosure is to provide a heat pump with improved heat transfer characteristics and high-temperature stability. [Means for solving the problem]

[0008] A refrigeration oil according to one embodiment of the present disclosure may contain a silane compound of the following chemical formula 1. [ka] In the above chemical formula 1, one or two of R1 to R4 are independently selected from C1-C5 alkoxy groups, and the remaining ones are independently C1-C5 14 It is an alkyl group.

[0009] In one embodiment, in the chemical formula 1, one or two of R1 to R4 can be independently selected from either a methoxy group or an ethoxy group.

[0010] In one embodiment, in the chemical formula 1, one or any two of the remaining groups may be a methyl group, an ethyl group, or a propyl group.

[0011] In one embodiment, in the chemical formula 1, any two of R1 to R4 may be independently selected from C1-C3 alkoxy groups, and the remaining two may each be independently C1-C2 linear alkyl groups or C3-C7 branched alkyl groups.

[0012] In one embodiment, the silane compound of chemical formula 1 may be included in an amount of 0.1% to 10% by weight, based on the total weight of the refrigeration oil.

[0013] In one embodiment, the material may further include a base oil and at least one additive.

[0014] In one embodiment, the base oil can be included in an amount of 87% to 99% by weight, based on the total weight of the refrigeration oil.

[0015] In one embodiment, the base oil may include at least one selected from the group consisting of polyol ester, polyalkylene glycol, polycarbonate, alkylbenzene, polyvinyl ether, polyether, and perfluoropolyether.

[0016] In one embodiment, the additive may include at least one of a stabilizer, an antioxidant, a corrosion inhibitor, an acid scavenger, an extreme pressure additive, and an anti-wear agent.

[0017] In one embodiment, the silane compound of chemical formula 1, the base oil, the stabilizer, the acid scavenger, and the wear-resistant agent may be included.

[0018] In one embodiment, after evaluating the high-temperature stability of the refrigeration oil under temperature conditions of 140°C to 160°C according to the ASHRAE Standard 97 test method, the total acid number (TAN) measured by the ASTM D664 test method may be 1 mgKOH / g or less.

[0019] In one embodiment, after evaluating the high-temperature stability of the refrigerant oil under temperature conditions of 140°C to 160°C using the ASHRAE Standard 97 test method, the color index measured by the ASTM D1500 test method may be 1 or less.

[0020] A composition for a refrigerator according to one embodiment of the present disclosure may include the aforementioned refrigerant oil and a refrigerant comprising CF3I.

[0021] In one embodiment, the refrigerant may further include a refrigerant other than CF3I.

[0022] A heat pump according to one embodiment of the present disclosure may include the aforementioned refrigerant oil. Effects of the Invention

[0023] The refrigerating machine oil according to an embodiment of the present disclosure can have improved high-temperature stability and long-term reliability.

[0024] The refrigerating machine composition according to an embodiment of the present disclosure can have improved heat transfer properties and high-temperature stability.

[0025] The heat pump according to an embodiment of the present disclosure can have improved heat transfer properties and oxidation stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] [Figure 1] FIG. 1 is a schematic diagram showing the flow of a refrigerant for heat exchange in a cooling mode of a heat exchanger in a heat pump system according to an embodiment. [Figure 2] FIG. 2 is a schematic diagram showing the flow of a refrigerant for heat exchange in a heating mode of a heat exchanger in a heat pump system according to an embodiment. Mode for Carrying Out the Invention

[0027] Hereinafter, embodiments of the present disclosure will be described in detail so that a person having ordinary knowledge in the technical field to which the present invention pertains can easily carry out the embodiments. However, these embodiments are merely illustrative and do not limit the present disclosure.

[0028] <Refrigerating Machine Oil> The refrigerating machine oil according to an embodiment of the present disclosure may contain a silane compound represented by the following Chemical Formula 1. Chemical Formula In Chemical Formula 1, any one or any two of R1 to R4 are each independently selected from C1-C5 alkoxy groups, and the remainder are each independently C1-C 14 alkyl groups.

[0029] As a result, the refrigeration oil can have improved heat transfer performance and high stability. The silane compound of chemical formula 1 can suppress or prevent side reactions caused by water and reduce the total acid value, and can function, for example, as an acid component reduction agent.

[0030] Silane compounds having three or four alkoxy groups as functional groups bonded to Si are prone to self-polymerization. This can lead to the formation of precipitates in the composition, discoloration of the composition, and a decrease in the stability and performance of the refrigeration oil.

[0031] In one embodiment, in the chemical formula 1, one or two of R1 to R4 can be independently selected from either a methoxy group or an ethoxy group. This further improves the stability of the refrigeration oil under high temperature and high pressure conditions.

[0032] In one embodiment, in the chemical formula 1, one or any two of the remaining groups may be a methyl group, an ethyl group, or a propyl group.

[0033] In one embodiment, in the chemical formula 1, one or two of the remaining groups may be a methyl group or an ethyl group.

[0034] In one embodiment, in the chemical formula 1, any two of R1 to R4 may be independently selected from C1-C3 alkoxy groups, and the remaining two may be independently C1-C2 linear alkyl groups or C3-C7 branched alkyl groups. The refrigerant oil can effectively reduce the generation of acidic components even when used in combination with highly reactive refrigerants such as CF3I. This improves stability under high temperature and high pressure conditions and suppresses chemical degradation of the refrigerant oil and compositions containing it during long-term operation, thereby improving the overall durability and reliability of the system.

[0035] In one embodiment, in the chemical formula 1, any one of the remaining members is C4-C 13 An alkyl group may also be used.

[0036] In this specification, the alkyl group may be a linear alkyl group or a branched alkyl group.

[0037] In one embodiment, in the chemical formula 1, one of R1 to R4 is a C1-C5 alkoxy group, any two are independently a methyl group or an ethyl group, and the remainder is a C1-C5 alkoxy group. 14 An alkyl group may also be used.

[0038] In one embodiment, in the chemical formula 1, one of R1 to R4 is a C1-C3 alkoxy group, any two are independently a methyl group or an ethyl group, and the remainder is a C3-C 14 An alkyl group may also be used.

[0039] In one embodiment, in the chemical formula 1, any two of R1 to R4 are independently C1-C5 alkoxy groups, one of which is a methyl group or an ethyl group, and the rest are C1-C5 14 An alkyl group may also be used.

[0040] In one embodiment, in the chemical formula 1, any two of R1 to R4 are independently C1-C3 alkoxy groups, one of which is a methyl group or an ethyl group, and the remaining is a C3-C3 alkoxy group. 14 An alkyl group may also be used.

[0041] In one embodiment, the silane compound of chemical formula 1 may include diisobutyldimethoxysilane and / or diethoxydimethylsilane.

[0042] In one embodiment, the silane compound of chemical formula 1 may be diisobutyldimethoxysilane or diethoxydimethylsilane.

[0043] In one embodiment, the refrigerant oil may contain 0.1% to 10% by weight of the silane compound of chemical formula 1, based on the total weight of the refrigerant oil. This prevents or suppresses side reactions caused by moisture present inside the air conditioning system, etc., without degrading the performance of the refrigerant oil. Furthermore, it prevents deterioration of the refrigeration composition containing the refrigerant oil, which functions as the working fluid in the system, and ensures the reliability of the composition over a long period of time.

[0044] The content of the silane compound of chemical formula 1 in the refrigerant oil may be, for example, 0.5% to 9.5% by weight, 1.0% to 7.0% by weight, 1.0% to 5.5% by weight, or 1.5% to 3.5% by weight.

[0045] As a non-limiting example, the silane compounds can be produced by the reaction of a Grignard reagent with an alkoxyalkylsilane, or by a hydrosilylation reaction under metal catalysis, and can also be obtained commercially, but are not limited to these methods.

[0046] In one embodiment, the refrigeration oil may further comprise a base oil and at least one additive.

[0047] In one embodiment, the refrigeration oil may contain 87% to 99% by weight of the base oil based on the total weight of the refrigeration oil. This allows the refrigeration oil to effectively form a lubricating film on metal contact surfaces that reciprocate or rotate in the compressor or other components within the aforementioned system, thereby reducing friction and wear.

[0048] The base oil content in the refrigeration oil may be, for example, 85% to 96% by weight, or 88% to 96% by weight.

[0049] In one embodiment, the base oil may include, for example, at least one selected from the group consisting of polyol ester, polyalkylene glycol, polycarbonate, alkylbenzene, polyvinyl ether, polyether, and perfluoropolyether.

[0050] In one embodiment, the refrigeration oil comprises 0.1% to 10% by weight of a silane compound and 87% to 99% by weight of a base oil, based on the total weight of the refrigeration oil, wherein the silane compound is represented by chemical formula 1, and in chemical formula 1, any two of R1 to R4 are independently C1 to C5 alkoxy groups, one of which is a methyl group or an ethyl group, and the remainder are C3 to C5 14 An alkyl group may also be used.

[0051] In one embodiment, the refrigeration oil may contain the additive in an amount of 0.1% to 15% by weight, based on the total weight of the refrigeration oil.

[0052] The additive may include, for example, at least one of a stabilizer, an antioxidant, a corrosion inhibitor, an acid scavenger, an extreme pressure additive, and an anti-wear agent.

[0053] The stabilizer may include, for example, at least one selected from the group consisting of paraffin, naphthene, aromatic hydrocarbons, benzene or naphthalene substituted or unsubstituted with linear or branched alkyl groups, polyvinylpyrrolidone, and dibenzyltoluene.

[0054] The alkyl-substituted naphthalene is also called alkylated naphthalene and may include, for example, monoalkylnaphthalene, dialkylnaphthalene, trialkylnaphthalene, tetraalkylnaphthalene, or mixtures thereof.

[0055] In one embodiment, the additive may include at least one of an antioxidant, a corrosion inhibitor, an acid scavenger, an extreme pressure additive, and an anti-wear agent to improve the stability, wear resistance, heat resistance, etc., of the refrigerant oil.

[0056] In one embodiment, the antioxidant may include at least one of a phenolic antioxidant, an amine-based antioxidant, a phosphorus-based antioxidant, and a sulfur-based antioxidant.

[0057] The antioxidant may include, for example, phenolic antioxidants such as 2,6-dibutylphenol, amine antioxidants such as phenylamine, diphenylamine, and naphthylamine, phosphorus antioxidants such as trialkylphosphite, trialkylphosphate, and trialkylphosphine, and sulfur-based antioxidants such as pentaerythrityltetrakis(3-laurylthiopropionate), dilaurylthiodipropionate, distearylthiodipropionate, and / or ditridecylthiodipropionate and dimyristylthiodipropionate.

[0058] In one embodiment, the corrosion inhibitor may include at least one of a thiazole compound, a triazole compound, and a thiadiazole compound.

[0059] In one embodiment, the acid scavenger can capture acidic impurities that may be present in the refrigeration oil or refrigeration composition, thereby improving stability.

[0060] The acid scavenger may include, for example, glycidyl ether compounds, such as triglycidyl ether, diglycidyl ether, glycidyl ether, lauryl glycidyl ether, and / or ethylhexyl glycidyl ether.

[0061] In one embodiment, the extreme pressure additive can reduce friction and wear by preventing direct contact between metals.

[0062] 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 extreme pressure additive of an organosulfur compound may be a monosulfide, polysulfide, sulfoxide, sulfone, thiosulfinate, sulfurized oil, thiocarbonate, thiophene, thiazole, methanesulfonate, or the like. The ester-based extreme pressure additive may be a higher fatty acid, a hydroxyaryl fatty acid, a polyol ester, or an acrylate. The organochlorine-based extreme pressure additive may be a chlorinated hydrocarbon or a chlorinated carboxylic acid derivative. The organofluorine-based extreme pressure additive may be a fluorinated aliphatic carboxylic acid, fluoroethylene resin, fluoroalkyl polysiloxane, or fluorinated graphite. The extreme pressure additive of the metal compound may be naphthenate (such as lead naphthenate), fatty acid salt (such as lead fatty acid), thiophosphate (such as zinc dialkyldithiophosphate), thiocarbamate, organomolybdenum compound, organotin compound, organogermanium compound, etc.

[0063] In one embodiment, the wear-resistant agent may include a phosphate-based wear-resistant agent. The phosphate-based wear-resistant agent may include, for example, at least one of trialkyl phosphates and triaryl phosphates, and may include, for example, tributyl phosphate, tripentyl phosphate, trihexyl phosphate, triphenyl phosphate, tris(methylphenyl) phosphate, and / or tricresyl phosphate.

[0064] In one embodiment, the refrigeration oil may include the silane compound of chemical formula 1, the base oil, the stabilizer, the acid scavenger, and the anti-wear agent.

[0065] As a non-limiting example, the refrigeration oil may further contain defoaming agents, load-bearing additives, chlorine scavenging agents, detergent dispersants, viscosity index improvers, oiliness agents, rust inhibitors, pour point depressants, and the like. For example, the defoaming agent may be a homopolymer or copolymer of acrylic esters.

[0066] In one embodiment, the refrigeration oil may have a total acid number (TAN) of 1 mgKOH / g or less, measured by the ASTM D664 test method after high-temperature stability evaluation at 140°C to 160°C based on the ASHRAE Standard 97 test method. ASTM D664 is an ASTM standard widely used for measuring the acid number of refrigeration oils.

[0067] The total acid value may be, for example, 0.8 mg KOH / g or less, 0.7 mg KOH / g or less, or less than 0.5 mg KOH / g. This allows the refrigeration oil to have improved operational stability.

[0068] In one embodiment, the refrigerant oil may have a color index of 1 or less measured by the ASTM D1500 test method after high-temperature stability evaluation at 140°C to 160°C based on the ASHRAE Standard 97 test method. The ASTM D1500 test method is a test method used for measuring the hue of refrigerant oil and is also called the ASTM Color Scale.

[0069] The aforementioned color index may be, for example, less than 0.5. This allows the refrigerant oil to have improved high-temperature stability.

[0070] The high-temperature stability evaluation at 140°C to 160°C based on the ASHRAE Standard 97 test method can be carried out, for example, in a sealed container in the presence of a metal catalyst. The metal catalyst may include, for example, transition metal catalysts and nonmetallic catalysts. Non-limiting examples include copper (Cu) catalysts, aluminum (Al) catalysts, and iron (Fe) catalysts.

[0071] The high-temperature stability evaluation can be performed, for example, by placing refrigerant oil, refrigerant, and metal catalyst in a sealed container and maintaining it at a temperature of 140°C to 160°C for approximately 10 to 15 days. In the high-temperature stability evaluation, the conditions can be set, for example, to a temperature of 145°C to 155°C and a period of 13 to 15 days.

[0072] For example, the refrigerant may include CF3I.

[0073] For example, after evaluating the high-temperature stability, the sealed container can be left at room temperature to cool. The refrigerant can be removed from the mixture of refrigerant oil and refrigerant removed from the sealed container, and in non-limiting examples, the refrigerant can be removed by reducing pressure and / or by nitrogen bubbling. The total acid number according to the ASTM D664 test method or the color index according to the ASTM D1500 test method can be measured for the refrigerant oil from which the refrigerant has been removed.

[0074] A refrigeration oil according to one embodiment of the present disclosure can be used in fields such as, for example, household and / or industrial refrigerators, cold storage warehouses, refrigeration equipment, household and / or commercial air conditioners, vehicle air conditioning systems, vapor compression heat pumps, and cooling systems for data centers and / or servers.

[0075] <Composition for refrigerators> A composition for a refrigerator according to one embodiment of the present disclosure may include the aforementioned refrigerant oil and a refrigerant comprising CF3I.

[0076] In one embodiment, the refrigerant may further include a refrigerant other than CF3I.

[0077] For example, the refrigerant composition may contain CF3I alone as the refrigerant, or it may contain CF3I in combination with a different type of refrigerant.

[0078] In one embodiment, the refrigerant other than CF3I may include at least one selected from the group consisting of hydrofluorocarbon (HFC) refrigerants, hydrofluoroolefin (HFO) refrigerants, and hydrochlorofluorocarbon (HCFC) refrigerants.

[0079] 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.

[0080] 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.

[0081] The aforementioned hydrochlorofluorocarbon (HCFC) refrigerants may include difluorochloromethane (R-22), chlorotetrafluoroethane (R-124), 1-chloro-1,1-difluoroethane (R-142b), and the like.

[0082] In one embodiment, the content of CF3I may be 0.1% to 100% by weight, based on the total weight of the refrigerant, for example, 10% or more by weight, 20% or more by weight, 30% or more by weight, 40% or more by weight, 50% or more by weight, or 60% or more by weight.

[0083] In one embodiment, the weight ratio of the refrigerant oil to the refrigerant in the refrigeration composition may be 1:9 to 9:1.

[0084] <Heat pump> A heat pump according to one embodiment of the present disclosure may include the aforementioned refrigerant oil. This allows the heat pump to have improved heat transfer characteristics and high-temperature stability.

[0085] In one embodiment, the refrigerant oil may circulate in a mixture with the refrigerant in at least a portion of the compressor within the heat pump.

[0086] The heat pump includes a compressor, a condenser, an expansion valve, and an evaporator, the condenser and the evaporator each of which can function as a heat exchanger.

[0087] In the compressor, the refrigerant is compressed into a high-temperature, high-pressure gas. The refrigerant releases heat in the condenser and can condense into a liquid state. Subsequently, the refrigerant expands to a low-temperature, low-pressure state as it passes through the expansion valve, and can vaporize into a gaseous state in the evaporator by absorbing heat from an external heat source.

[0088] The condenser and evaporator act as heat exchangers that perform heat exchange through the refrigerant, and the refrigerant can repeatedly release or absorb heat while circulating within the heat pump.

[0089] The heat pump can perform either cooling or heating functions depending on the operating mode. In cooling mode, it releases heat from the room to the outside, and in heating mode, it transfers heat from the outside into the room.

[0090] In some embodiments, the coefficient of performance (COP) of the heat pump may be 1 to 10. Here, the coefficient of performance (COP) refers to the ratio of the amount of effective heat obtained to the energy input during the operation of the heat pump. By using the aforementioned refrigerant, it is possible to provide a highly efficient heat pump with a COP in the range of 1 to 10.

[0091] The aforementioned heat pump can be applied to a wide range of fields, including residential, commercial, and industrial use, and can operate efficiently over a wide operating temperature range from -20°C to 50°C.

[0092] Figures 1 and 2 are schematic diagrams illustrating the flow of refrigerant for heat exchange in a heat exchanger within a heat pump during either the cooling or heating mode, according to one embodiment.

[0093] The arrows in Figures 1 and 2 indicate the flow of the refrigerant.

[0094] Referring to Figure 1, in cooling mode, the refrigerant is compressed by the compressor 60, sequentially bypasses the internal condenser 70 and the expansion valve (heating) 22, releases heat in the external condenser 10, expands in the expansion valve (cooling) 21, and can reabsorb heat in the evaporator 40.

[0095] For example, in cooling mode, the refrigerant gas may be compressed, increasing its pressure and temperature. This prepares the refrigerant to release heat as it moves to the external condenser. Because the system is in cooling mode, the refrigerant can bypass the internal condenser 70 and the expansion valve (heating) 22. This allows the cycle to focus on releasing heat to the outside and absorbing heat from the inside. The high-temperature, high-pressure refrigerant then flows into the external condenser 10, releasing heat into the outside air. This cools the refrigerant, allowing it to condense into a liquid state. The liquid refrigerant then expands as it passes through the expansion valve (cooling) 21, causing its pressure and temperature to decrease. This prepares the refrigerant to absorb heat. The low-temperature, low-pressure refrigerant then flows into the evaporator coil, cooling the space by absorbing heat from the indoor air. The refrigerant can complete the cycle by evaporating again in a gaseous state.

[0096] Referring to Figure 2, in heating mode, the refrigerant is compressed by the compressor 60, releases heat in the internal condenser 70, expands in the expansion valve (heating) 22, absorbs heat in the external condenser 10, and can then absorb additional heat in the cooler 30.

[0097] For example, in heating mode, the refrigerant can first be compressed by the compressor 60. This increases the pressure and temperature of the refrigerant, preparing it to effectively release heat. The refrigerant then flows into the internal condenser 70, where the high-temperature refrigerant can transfer energy to the space being heated, heating the space while condensing in a liquid state. Next, the refrigerant can pass through the expansion valve (heating) 22. This lowers the pressure and temperature of the refrigerant, preparing it to absorb heat. The refrigerant then can flow into the external condenser 10, which in heating mode functions as an evaporator, allowing the refrigerant to absorb heat from the outside air even under cold conditions. Next, the refrigerant passes through the cooler 30, where it can absorb additional heat to maximize efficiency before returning to the compressor 60. This cycle allows for the continuous extraction of heat from the external environment and transfer to the room, and the cooler can provide an additional absorption step to improve performance and reliability.

[0098] On the other hand, referring to Figures 1 and 2, the system including the heat pump may further include a valve 20, a motor inverter 35, an accumulator 50, a PTC heater 80, and a battery 90, which can be arranged to be fluidly or electrically connected to the components of the system.

[0099] As a non-limiting example, the valve 20 is for selectively switching the path of the refrigerant flow and can be positioned to control the direction of refrigerant flow when switching between cooling and heating modes. The accumulator 50 is for temporarily storing the refrigerant or for gas-liquid separation and can be positioned to stabilize the state of the refrigerant flowing into the compressor 60.

[0100] Furthermore, the motor inverter 35 is a power conversion device for controlling the drive of the compressor 60, and can be configured so that the rotational speed and output of the compressor are adjusted according to the requirements. The PTC heater 80 is an auxiliary heating means for providing additional heating as needed, and can be positioned to complement the heating performance. The battery 90 can be electrically connected to the system as a power supply device that supplies power to the compressor 60, motor inverter 35, and PTC heater 80, etc.

[0101] As described above, the components shown in Figures 1 and 2 work together organically during the operation of the heat pump system in both cooling and heating modes, enabling the refrigerant heat exchange cycle to run stably and efficiently.

[0102] The embodiments of this disclosure will be further described below with reference to specific experimental examples. The examples and comparative examples included in the experimental examples are illustrative of this disclosure and do not limit the scope of the attached claims.

[0103] Examples 1-5 and Comparative Examples 1-6 Based on the components and content shown in Table 1 below, refrigeration oils were prepared according to the examples and comparative examples. Details of the silane compounds used are shown in Table 2.

[0104] [Table 1]

[0105] The details of the components shown in Table 1 are as follows: -Base oil: Polyol ester (POE) (Synastive ES 4068, manufactured by BASF) - Stabilizer: Alkylated naphthalene (Synesstic 5, manufactured by Exxon Mobile) - Anti-wear agent: Tris(methylphenyl) phosphate (RC 3661, manufactured by Lanxess) - Acid scavenger: 2-ethylhexylglycidyl ether (CAS 2461-15-6)

[0106] [Table 2(1)] [Table 2(2)]

[0107] Experimental example Experimental Example 1: Total Acid Number (TAN) To 100 parts by weight of each refrigeration oil produced in the above-described examples and comparative examples, 100 parts by weight of CF3I was mixed as a refrigerant to prepare test compositions for high-temperature stability evaluation according to the ASHRAE Standard 97 test method. The high-temperature stability evaluation of each test composition was carried out according to the following procedure. First, the test composition was placed in a container (tube) together with copper (Cu), aluminum (Al), and iron (Fe) catalysts and sealed. Specifically, high-purity copper, aluminum alloy Al3003, and carbon steel were used as the Cu, Al, and Fe catalysts, respectively. The sealed container was then stored in a temperature-controlled environment at approximately 150°C, and this high-temperature condition was maintained continuously and uniformly throughout the entire test period. The container was maintained under these constant thermal conditions without interruption for approximately 14 days, ensuring that the refrigerant-oil mixture and catalysts were continuously exposed to high temperatures during the stability evaluation period. After that, the sealed container was allowed to cool to room temperature, and the test composition was removed from the container. Next, CF3I was removed from the test composition by reduced pressure and nitrogen bubbling. Specifically, CF3I was removed from the test composition through a two-step process including reduced pressure and nitrogen bubbling. First, the volatile CF3I was separated from the refrigerant oil by reduced pressure. Then, any remaining CF3I was further removed by passing nitrogen gas through the composition in a bubble form. This procedure yielded a sample of refined refrigerant oil suitable for measuring the acid value. The total acid number of the refrigerant oil after CF3I removal was measured using a 686 Titroprocessor (Metrohm) in accordance with ASTM D664. A lower TAN value indicates higher oxidation stability of the refrigeration oil. The results are shown in Table 3 below.

[0108] Experimental Example 2: ASTM Color Index Each refrigerant oil produced in the above-described examples and comparative examples was subjected to high-temperature stability evaluation based on the ASHRAE Standard 97 test method using the same method and conditions as in Experimental Example 1. Subsequently, the sealed container was left at room temperature to cool, and the test composition was removed from the container. Next, CF3I was removed from the test composition by reduced pressure and nitrogen bubbling. Specifically, CF3I was removed from the test composition by a two-step process including reduced pressure and nitrogen bubbling. First, volatile CF3I was separated from the refrigerant oil by reduced pressure. Then, any remaining CF3I was further removed by passing nitrogen gas through the composition in the form of bubbles. This procedure yielded a sample of refined refrigerant oil suitable for measurement of the ASTM color index. The color index of the refrigerant oil after CF3I removal was evaluated using a LICO 500-Spectral colorimeter (HACH LANGE) in accordance with ASTM D1500. Specifically, each refrigerant oil was placed in a test tube and compared to a standard color glass, and the standard color number that best matched the color was recorded. If the sample color did not exactly match the standard color, a number closer to the darker side was selected. The ASTM color index is expressed in the range of 0.5 to 8.0, which are standard color numbers, and the less color variation there is, the higher the chemical stability of the refrigerant oil. The results are shown in Table 3 below.

[0109] [Table 3]

[0110] Referring to Table 3, as a result of the high-temperature stability evaluation based on the ASHRAE Standard 97 test method, the refrigerating machine oil of the example exhibited lower total acid value and ASTM color index than the refrigerating machine oil of the comparative example.

[0111] On the other hand, as in the comparative example, when three or more alkoxy groups are bonded to the Si of the silane compound, or an alkoxy group or a C1-C 14 alkyl group is not bonded, or an aminoalkyl group is bonded, formation of a precipitate and discoloration occurred after the high-temperature stability evaluation based on the ASHRAE Standard 97 test method.

[0112] These experimental results show that the refrigerating machine oil according to the example has improved high-temperature stability compared to the oil of the comparative example, the generation of acidic decomposition products is reduced, and the appearance and chemical quality are maintained better.

Claims

1. Refrigerating oil containing a silane compound of the following chemical formula 1. 【Chemistry 1】 (In the above chemical formula 1, R １ ~R ４ Any one or any two of these are independently C １ -C ５ Selected from the alkoxy groups, the rest are each independently C １ -C １４ It is an alkyl group.

2. In the above chemical formula 1, R １ ~R ４ The refrigerant oil according to claim 1, wherein one or two of the groups are independently selected from a methoxy group or an ethoxy group.

3. The refrigerating oil according to claim 1, wherein in the chemical formula 1, any one or any two of the remaining groups is a methyl group, an ethyl group, or a propyl group.

4. In Chemical Formula 1 above, R １ to R ４ , any two of which are each independently selected from C １ -C ３ alkoxy groups, and the remaining two are each independently C １ -C ２ linear alkyl groups or C ３ -C ７ branched alkyl groups. The refrigerating machine oil according to claim 1.

5. The refrigerant oil according to claim 1, wherein the refrigerant oil contains 0.1% to 10% by weight of the silane compound of chemical formula 1, based on the total weight of the refrigerant oil.

6. The refrigerant oil according to claim 1, further comprising a base oil and at least one additive.

7. The refrigerant oil according to claim 6, wherein the base oil is contained in an amount of 87% to 99% by weight, based on the total weight of the refrigerant oil.

8. The refrigeration oil according to claim 6, wherein the base oil comprises at least one selected from the group consisting of polyol ester, polyalkylene glycol, polycarbonate, alkylbenzene, polyvinyl ether, polyether, and perfluoropolyether.

9. The refrigerating oil according to claim 6, wherein the additive comprises at least one of a stabilizer, an antioxidant, a corrosion inhibitor, an acid scavenger, an extreme pressure additive, and an anti-wear agent.

10. The refrigerant oil according to claim 9, comprising the silane compound of chemical formula 1, the base oil, the stabilizer, the acid scavenger, and the anti-wear agent.

11. The refrigerating oil according to claim 1, wherein, after evaluating high-temperature stability under temperature conditions of 140°C to 160°C according to the ASHRAE Standard 97 test method, the total acid number (TAN) measured by the ASTM D664 test method is 1 mg KOH / g or less.

12. The refrigerating oil according to claim 1, wherein, after evaluating high-temperature stability under temperature conditions of 140°C to 160°C according to the ASHRAE Standard 97 test method, the color index measured by the ASTM D1500 test method is 1 or less.

13. A refrigerating oil according to any one of claims 1 to 12, CF ３ A refrigeration composition comprising a refrigerant containing I.

14. The refrigerant is CF ３ The refrigeration composition according to claim 13, further comprising a refrigerant other than I.

15. A heat pump comprising the refrigerant oil described in any one of claims 1 to 12.

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