Refrigerator oil, composition for refrigerator, and heat pump

Abstract

A refrigerator oil, according to embodiments of the present disclosure, comprises a silane-based compound of chemical formula 1 below. In chemical formula 1, any one or any two among R1 to R4 are each independently selected from C1-C5 alkoxy groups, and the rest are each independently from C1-C14 alkyl groups. A composition for a refrigerator, according to embodiments of the present disclosure, comprises the refrigerator oil and a refrigerant. A heat pump, according to embodiments of the present disclosure, comprises the refrigerator oil. [Chemical formula 1]

Description

Refrigeration oil, composition for refrigeration, and heat pump

[0001] The embodiments of the present application relate to refrigeration oil, a composition for a refrigeration unit, and a heat pump.

[0002]

[0003] Working fluids, including refrigerants and refrigeration oils, can be used for heat exchange as materials capable of transferring heat in air conditioning or refrigeration systems. An air conditioning system may refer to, for example, a system that maintains a comfortable state by controlling the temperature, humidity, and air composition of an indoor environment. Air conditioning or refrigeration systems can be applied to buildings, factories, homes, vehicles, airplanes, etc.

[0004] Refrigeration oil circulates within the system described above and can contribute to the lubrication, cooling, sealing, cleaning, or control of the solubility of the refrigerant of mechanical components such as compressors, and can circulate together with the refrigerant in some sections.

[0005] Examples of refrigerants include fluorocarbon compounds, and research and development to improve their stability in working fluids are continuously being carried out.

[0006]

[0007] One objective of the present disclosure is to provide a refrigeration oil having improved high-temperature stability.

[0008] One objective of the present disclosure is to provide a composition for a refrigerator having improved heat transfer characteristics and high temperature stability.

[0009] One objective of the present disclosure is to provide a heat pump having improved heat transfer characteristics and high temperature stability.

[0010]

[0011] A refrigeration oil according to one embodiment of the present disclosure may include a silane compound of the following chemical formula 1.

[0012] [Chemical Formula 1]

[0013]

[0014] In the above 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 selected from C1-C 14 It is an alkyl group.

[0015] In one embodiment, in the above formula 1, any one or any two of R1 to R4 may each be independently selected from a methoxy group or an ethoxy group.

[0016] In one embodiment, in the formula 1, any one or two of the remainder may be a methyl group, an ethyl group, or a propyl group.

[0017] In one embodiment, any two of R1 to R4 in Formula 1 are each independently selected from C1-C3 alkoxy groups, and the remaining two may each independently be C1-C2 linear alkyl groups or C3-C7 branched alkyl groups.

[0018] In one embodiment, the silane compound of Formula 1 may be included in an amount of 0.1% to 10% by weight based on the total weight of the refrigeration oil.

[0019] In one embodiment, at least one of the base oil and additive may be further included.

[0020] In one embodiment, the base oil may be included in an amount of 87% to 99% by weight based on the total weight of the refrigeration base oil.

[0021] In one embodiment, the base oil may comprise at least one selected from the group consisting of polyol ester, polyalkylene glycol, polycarbonate, alkylbenzene, polyvinyl ether, polyether, and perfluoropolyether.

[0022] In one embodiment, the additive may include at least one of a stabilizer, an antioxidant, a corrosion inhibitor, an acid capture agent, an extreme pressure additive, and an anti-wear agent.

[0023] In one embodiment, the product may include the silane compound of Formula 1, the base oil, the stabilizer, the acid capture agent, and the anti-wear agent.

[0024] In one embodiment, the total acid number (TAN) measured according to the ASTM D664 test method 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 may be 1 mg KOH / g or less.

[0025] In one embodiment, the color index measured according to the ASTM D1500 test method 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 may be 1 or less.

[0026] A composition for a refrigerator according to one embodiment of the present disclosure may include the refrigerator oil described above and a refrigerant comprising CF3I.

[0027] In one embodiment, the refrigerant may further include a refrigerant other than CF3I.

[0028] A heat pump according to one embodiment of the present disclosure may include the refrigeration oil described above.

[0029]

[0030] A refrigeration oil according to one embodiment of the present disclosure may have improved high-temperature stability and long-term reliability.

[0031] A composition for a refrigerator according to one embodiment of the present disclosure may have improved heat transfer characteristics and high temperature stability.

[0032] A heat pump according to one embodiment of the present disclosure may have improved heat transfer characteristics and oxidation stability.

[0033]

[0034] FIGS. 1 and FIGS. 2 are schematic diagrams illustrating the flow of refrigerant for heat exchange in a cooling mode or a heating mode of a heat exchanger in a heat pump system according to one embodiment, respectively.

[0035]

[0036] Hereinafter, embodiments of the present disclosure are described in detail so that those skilled in the art can easily practice the present invention. However, this is merely illustrative and the present invention is not limited to the illustratively described embodiments.

[0037]

[0038] Refrigeration oil

[0039] A refrigeration oil according to one embodiment of the present disclosure may include a silane compound of the following chemical formula 1.

[0040] [Chemical Formula 1]

[0041]

[0042] In the above 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 selected from C1-C 14 It can be an alkyl group.

[0043] Accordingly, the above refrigeration oil can have improved heat transfer performance and high stability. The silane compound of Formula 1 can reduce the total acid value by suppressing or preventing side reactions caused by moisture, and can function, for example, as a reducing agent for the formation of acid components.

[0044] In the case of silane compounds having three or four alkoxy groups as functional groups bonded to Si, self-polymerization reactions can easily occur, and accordingly, precipitates may be formed in the composition or the color of the composition may change.

[0045] In one embodiment, in Formula 1, any one or any two of R1 to R4 may each be independently selected from a methoxy group or an ethoxy group. Accordingly, the stability of the refrigeration oil under high temperature and high pressure conditions can be further improved.

[0046] In one embodiment, in the formula 1, any one or two of the remainder may be a methyl group, an ethyl group, or a propyl group.

[0047] In one embodiment, in the formula 1, any one or any two of the remainder may be a methyl group or an ethyl group.

[0048] In one embodiment, any two of R1 to R4 in Formula 1 are each independently selected from C1-C3 alkoxy groups, and the remaining two are each independently C1-C2 linear alkyl groups or C3-C7 branched alkyl groups. Accordingly, even when the refrigeration oil is used with a highly reactive refrigerant such as CF3I, the generation of acid components can be effectively reduced, thereby further improving stability under high temperature and high pressure conditions.

[0049] In one embodiment, any one of the remainders in Formula 1 is C4-C 13 It can be an alkyl group.

[0050] In this specification, the alkyl group may be a linear alkyl group or a branched alkyl group.

[0051] In one embodiment, in Formula 1, any one of R1 to R4 is a C1-C5 alkoxy group, any two are each independently a methyl group or an ethyl group, and the remainder is a C1-C 14 It can be an alkyl group.

[0052] In one embodiment, in Formula 1, any one of R1 to R4 is a C1-C3 alkoxy group, any two are each independently a methyl group or an ethyl group, and the remainder is a C3-C 14 It can be an alkyl group.

[0053] In one embodiment, any two of R1 to R4 in Formula 1 are each independently a C1-C5 alkoxy group, any one is a methyl group or an ethyl group, and the remainder is a C1-C 14 It can be an alkyl group.

[0054] In one embodiment, any two of R1 to R4 in Formula 1 are each independently a C1-C3 alkoxy group, any one is a methyl group or an ethyl group, and the remainder is a C3-C 14 It can be an alkyl group.

[0055] In one embodiment, the silane compound of Formula 1 may include diisobutyldimethoxysilane and / or diethoxydimethylsilane.

[0056] In one embodiment, the silane compound of Formula 1 may be diisobutyldimethoxysilane or diethoxydimethylsilane.

[0057] In one embodiment, the refrigeration oil may contain 0.1% to 10% by weight of a silane compound of Formula 1 based on the total weight of the refrigeration oil. Accordingly, side reactions caused by moisture present inside a system, such as an air conditioning system, can be prevented or suppressed without reducing the performance of the refrigeration oil. Accordingly, the deterioration of a refrigeration composition containing the refrigeration oil, which can act as an operating fluid within the system, is prevented, and the composition can maintain reliability for a long period.

[0058] The content of the silane compound of Formula 1 in the above refrigeration oil may be, for example, 0.5 wt% to 9.5 wt%, 1.0 wt% to 7.0 wt%, 1.0 wt% to 5.5 wt%, or 1.5 wt% to 3.5 wt%.

[0059] As a non-limiting example, the silane compound may be prepared by a reaction between a Grignard reagent and an alkoxyalkylsilane or by a hydrosililation reaction under a metal catalyst, or may be obtained from a commercial reagent supplier, but is not limited thereto.

[0060] In one embodiment, the refrigeration oil may further include at least one of the base oil and the additive.

[0061] 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. Accordingly, the refrigeration oil can effectively form a lubricating film between metal contact surfaces during reciprocating or rotational motion of a compressor, etc., within the system described above, thereby reducing friction and wear.

[0062] The content of the base oil in the above refrigeration base oil may be, for example, 85% to 96% by weight or 88% to 96% by weight.

[0063] In one embodiment, the base oil may comprise at least one selected from the group consisting of, for example, polyol ester, polyalkylene glycol, polycarbonate, alkylbenzene, polyvinyl ether, polyether, and perfluoropolyether.

[0064] 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 Formula 1, and any two of R1 to R4 in Formula 1 are each independently a C1-C5 alkoxy group, any one is a methyl group or an ethyl group, and the remainder is a C3-C 14 It can be an alkyl group.

[0065] 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.

[0066] The above additive may include, for example, at least one of a stabilizer, an antioxidant, a corrosion inhibitor, an acid capture agent, an extreme pressure additive, and an anti-wear agent.

[0067] The above stabilizer may include at least one selected from the group consisting of, for example, paraffin, naphthene, aromatic hydrocarbon, benzene or naphthalene substituted or unsubstituted with a linear or branched alkyl group, polyvinylpyrrolidone, and dibenzyl toluene.

[0068] The naphthalene substituted with the above alkyl group may be referred to as alkylated naphthalene and may include, for example, monoalkyl naphthalene, dialkyl naphthalene, trialkyl naphthalene, tetraalkyl naphthalene, or a mixture thereof.

[0069] In one embodiment, the additive may include at least one of an antioxidant, a corrosion inhibitor, an acid capture agent, an extreme pressure additive, and a wear-resistant agent to improve the stability, wear resistance, heat resistance, etc. of the refrigeration oil.

[0070] 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.

[0071] The above antioxidants may include, for example, phenolic antioxidants such as 2,6-dibutylphenol, amine-based antioxidants such as phenylamine, diphenylamine and naphthylamine, phosphorus-based antioxidants such as trialkylphosphite, trialkylphosphate and trialkylphosphine, and sulfur-based antioxidants such as pentaerythrityl tetrakis(3-lauryl thiodipropionate), dilauryl thiodipropionate, distearyl thiodipropionate, and / or ditridecyl thiodipropionate and dimyristyl thiodipropionate.

[0072] In one embodiment, the corrosion inhibitor may include at least one of a thiazole-based compound, a triazole-based compound, and a thiadiazole-based compound.

[0073] In one embodiment, the acid capture agent can improve stability by capturing acidic impurities that may be included in the refrigeration oil or the composition for the refrigeration unit.

[0074] The above acid capture agent may include, for example, glycidyl ether-based compounds, and may include, for example, triglycidyl ether, diglycidyl ether, glycidyl ether, lauryl glycidyl ether and / or ethylhexyl glycidyl ether.

[0075] In one embodiment, the extreme pressure additive can reduce friction and wear by preventing direct contact between metals.

[0076] The above extreme pressure additives may be extreme pressure additives of organic sulfur compounds, extreme pressure additives of phosphorothioate esters, ester-based extreme pressure additives, organic chlorine-based extreme pressure additives, organic fluorine-based extreme pressure additives, alcohol-based extreme pressure additives, metal compound extreme pressure additives, etc. The above extreme pressure additives of organic sulfur compounds may be monosulfides, polysulfides, sulfoxides, sulfones, thiosulfinates, sulfurized oils, thiocarbonates, thiophenes, thiazoles, methanesulfonates, etc. The above ester-based extreme pressure additives may be higher fatty acids, hydroxyaryl fatty acids, polyol esters, acrylates, etc. The above organic chlorine-based extreme pressure additives may be chlorinated hydrocarbons or chlorinated carboxylic acid derivatives, 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 metal compound extreme pressure additive may be a naphthenate (lead naphthenic acid, etc.), a fatty acid salt (lead fatty acid salt, etc.), a thiophosphate (zinc dialkyl dithiophosphate, etc.), a thiocarbamate, an organic molybdenum compound, an organic tin compound, an organic germanium compound, etc.

[0077] 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 phosphate and triaryl phosphate, and may include, for example, tributyl phosphate, tripentyl phosphate, trihexyl phosphate, triphenyl phosphate, tris(methylphenyl) phosphate and / or tricresyl phosphate.

[0078] In one embodiment, the refrigeration base oil may include a silane compound of Formula 1, the base oil, the stabilizer, the acid capture agent, and the anti-wear agent.

[0079] As a non-limiting example, the refrigeration oil may further include an antifoamer, a load-bearing additive, a chlorine capture agent, a cleaning dispersant, a viscosity index improver, an oiliness agent, a rust inhibitor, a pour point depressant, etc. For example, the antifoamer may be a homopolymer or copolymer of an acrylic ester.

[0080] In one embodiment, the total acid number (TAN) measured according to the ASTM D664 test method 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 may be 1 mg KOH / g or less. ASTM D664 is used as an ASTM standard that specifies a test method for measuring the acid number of refrigeration oil.

[0081] The above acid value may be, for example, 0.8 mgKOH / g or less, 0.7 mgKOH / g or less, or less than 0.5 mgKOH / g. Accordingly, the above refrigeration oil may have improved operational stability.

[0082] In one embodiment, the color index measured according to the ASTM D1500 test method 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 may be 1 or less. The ASTM D1500 test method is used as a test method for measuring the color of refrigeration oil and may be referred to as the ASTM Color Scale.

[0083] The above color index may be, for example, less than 0.5. Accordingly, the above refrigeration oil may have improved high-temperature stability.

[0084] High-temperature stability evaluation under temperature conditions of 140°C to 160°C according to the above ASHRAE Standard 97 test method may be performed, for example, in a sealed container in the presence of a metal catalyst. The metal catalyst may include, for example, transition metal catalysts and non-metal catalysts. As a non-limiting example, the metal catalyst may include copper (Cu) catalyst, aluminum (Al) catalyst, and iron (Fe) catalyst.

[0085] The above high-temperature stability evaluation can be performed, for example, by placing refrigeration oil, refrigerant, and metal catalyst in a sealed container and storing it at a temperature of 140°C to 160°C for about 10 to 15 days. In the above high-temperature stability evaluation, for example, the temperature can be set to 145°C to 155°C and the period can be set to 13 to 15 days.

[0086] For example, the above refrigerant may include CF3I.

[0087] For example, after the high-temperature stability evaluation, the sealed container may be left at room temperature to cool. The refrigerant may be removed from the mixture of refrigerant oil and refrigerant removed from the sealed container, and, as a non-limiting example, the refrigerant may be removed through depressurization and / or nitrogen bubbling. For the refrigerant-removed refrigerant oil, the total acid number may be measured according to the ASTM D664 test method, or the color index may be measured according to the ASTM D1500 test method.

[0088] A refrigeration oil according to one embodiment of the present disclosure may be used in fields such as, for example, household and / or industrial refrigerators, cold storage warehouses, refrigeration units, household and / or commercial air conditioners, vehicle air conditioning systems, vapor compression heat pumps, data centers and / or server cooling systems.

[0089]

[0090] Composition for Refrigeration Units

[0091] A composition for a refrigerator according to one embodiment of the present disclosure may include the refrigerator oil described above and a refrigerant comprising CF3I.

[0092] In one embodiment, the refrigerant may further include a refrigerant other than CF3I.

[0093] For example, the above refrigerant composition may include CF3I alone as a refrigerant, or may include CF3I together with other types of refrigerants.

[0094] 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.

[0095] The above hydrofluorocarbon (HFC) refrigerants are difluoromethane (R-32), 1,1-difluoroethane (R-152a), pentafluoroethane (R-125), 1,1,1,2-tetrafluoroethane (R-134a), 1,1,1-trifluoroethane (R-143a), trifluoromethylmethyl ether (R-143a), 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), 1,1,1,3,3-pentafluoropropane (R-245fa), It may include octafluorocyclobutane (RC318), 1,1,1,3,3-pentafluorobutane (R-365mfc), etc.

[0096] 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.

[0097] The above hydrochlorofluorocarbon (HCFC) refrigerant may include difluorochloromethane (R-22), chlorotetrafluoroethane (R-124), 1-chloro-1,1-difluoroethane (R-142b), etc.

[0098] In one embodiment, the content of CF3I based on the total weight of the refrigerant may be 0.1 wt% to 100 wt%, and for example, 10 wt% or more, 20 wt% or more, 30 wt% or more, 40 wt% or more, 50 wt% or more, or 60 wt% or more.

[0099] In one embodiment, the weight ratio of the refrigeration oil and the refrigerant in the refrigeration composition may be 1:9 to 9:1.

[0100]

[0101] Heat Pump

[0102] A heat pump according to one embodiment of the present disclosure may include the refrigeration oil described above. Accordingly, the heat pump may have improved heat transfer characteristics and high-temperature stability.

[0103] In one embodiment, the refrigeration oil may be circulated in a mixture state mixed with a refrigerant in at least some of the compressors within the heat pump.

[0104] The above heat pump may include a compressor, a condenser, an expansion valve, and an evaporator, and the condenser and the evaporator may each function as heat exchangers.

[0105] In the above compressor, the refrigerant can be compressed to become a gaseous state at high temperature and high pressure, and the refrigerant can release heat in the condenser to condense into a liquid state. Subsequently, the refrigerant expands to a low temperature and low pressure state while passing through the expansion valve, and can vaporize into a gaseous state by absorbing an external heat source in the evaporator.

[0106] The above condenser and evaporator can function as heat exchangers that exchange heat using a refrigerant as a medium, and the refrigerant can repeat the process of releasing or absorbing heat as it circulates inside the heat pump.

[0107] The above heat pump can perform cooling or heating functions depending on the operating mode; in cooling mode, it releases indoor heat to the outside, and in heating mode, it transfers outdoor heat to the inside.

[0108] 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. Accordingly, by using the refrigerant described above, a high-efficiency heat pump having a COP in the range of 1 to 10 can be provided.

[0109] The above heat pump is applicable to various fields such as residential, commercial, and industrial use, and can be operated efficiently over a wide operating temperature range from -20°C to 50°C.

[0110] FIGS. 1 and FIGS. 2 are schematic diagrams illustrating the flow of refrigerant for heat exchange in a cooling mode or a heating mode of a heat exchanger in a heat pump according to one embodiment, respectively.

[0111] In Figures 1 and 2, the direction of the arrows is intended to indicate the flow of the refrigerant.

[0112] Referring to FIG. 1, in cooling mode, the refrigerant is compressed through the compressor (60), bypasses the internal condenser (70) and the expansion valve (heating) (22) in sequence, releases heat in the external condenser (10), expands in the expansion valve (cooling) (21), and can reabsorb heat through the evaporator (40).

[0113] For example, in cooling mode, the refrigerant gas can be compressed, causing its pressure and temperature to rise. This prepares the refrigerant to release heat as it moves to the external condenser. Since the system is in cooling mode, the refrigerant can bypass the internal condenser (70) and the expansion valve (heating) (22), allowing the cycle to focus on releasing heat to the outside and absorbing heat from the inside. Subsequently, the refrigerant in a high-temperature, high-pressure state can flow into the external condenser (10) to release heat into the outside air. Accordingly, the refrigerant can condense into a liquid state as it cools. Subsequently, the liquid refrigerant can expand as it passes through the expansion valve (cooling) (21), causing its pressure and temperature to decrease. This prepares the refrigerant to absorb heat. The refrigerant in a low-temperature, low-pressure state can flow into the evaporator coil to cool the space by absorbing heat from the indoor air. The refrigerant can then complete the cycle by evaporating back into a gaseous state.

[0114] Referring to FIG. 2, in heating mode, the refrigerant is compressed through 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 through the cooler (30).

[0115] For example, in heating mode, the refrigerant can first be compressed by a compressor (60), thereby increasing the pressure and temperature of the refrigerant and preparing it to effectively release heat. Afterward, the refrigerant can be introduced into an internal condenser (70), where the high-temperature refrigerant can transfer energy to a space to be heated, condensing into a liquid state to heat the space. Next, the refrigerant can pass through an expansion valve (heating) (22), thereby decreasing the pressure and temperature of the refrigerant and preparing it to absorb heat. Afterward, the refrigerant can be introduced into an external condenser (10), whereby in heating mode, the external condenser functions as an evaporator, allowing the refrigerant to absorb heat from the outside air even under cold conditions. Next, the refrigerant can pass through a cooler (30), where it can absorb additional heat before returning to the compressor (60) to maximize efficiency. Through this cycle, heat can be continuously extracted from the external environment and transferred into the room, and the cooler can provide an additional absorption step to improve performance and reliability.

[0116] Meanwhile, referring to FIGS. 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 may be arranged to be fluidly or electrically connected to the system components.

[0117] As a non-limiting example, the valve (20) is configured to selectively switch the flow path of the refrigerant and may be positioned to control the flow direction of the refrigerant when switching between cooling mode and heating mode. The accumulator (50) is configured to temporarily store the refrigerant or perform gas-liquid separation and may be positioned to stabilize the state of the refrigerant flowing into the compressor (60).

[0118] Additionally, the motor inverter (35) is a power conversion device for controlling the operation of the compressor (60), and can be configured so that the rotational speed and output of the compressor are adjusted according to requirements. The PTC heater (80) is an auxiliary heating means for providing additional heating when necessary and can be positioned to supplement 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.

[0119] In this way, each component illustrated in FIGS. 1 and 2 is organically linked during the cooling and heating modes of the heat pump system, so that the heat exchange cycle of the refrigerant can be performed stably and efficiently.

[0120]

[0121] In the following, embodiments of the present disclosure are further described with reference to specific experimental examples. The embodiments and comparative examples included in the experimental examples are merely illustrative of the present disclosure and do not limit the appended claims.

[0122]

[0123] Examples 1 to 5 and Comparative Examples 1 to 6

[0124] Refrigeration oils according to the examples and comparative examples were prepared by mixing the components listed in Table 1 below in their respective amounts. The specific types of silane compounds included in each refrigeration oil are shown in Table 2 below.

[0125]

[0126] Refrigeration oil component Silane compound Polyol ester Alkylated naphthalene-less (methylphenyl)phosphate 2-ethylhexyl glycidyl ether Weight % 391 31.5 1.5

[0127] The components listed in Table 1 above are specifically as follows.

[0128] - Base Oil: Polyol Ester (POE) (Synastive ES 4068, BASF)

[0129] - Stabilizer: Alkylated naphthalene (Synesstic 5, ExxonMobil)

[0130] - Anti-wear agent: Tris(methylphenyl)phosphate (RC 3661, Lanxess)

[0131] - Acid capture agent: 2-ethylhexyl glycidyl ether (CAS 2461-15-6)

[0132]

[0133] Silane Compound Example 1 Dimethoxy(methyl)-n-octylsilane Example 2 Methoxy(dimethyl)-n-octylsilane Example 3: Diisobutyl dimethoxysilane Example 4 Diethoxydimethylsilane Example 5 Dibutoxydimethylsilane Comparative Example 1: Vinyl Triethoxysilane Comparative Example 2 (N,N-dimethylaminopropyl)trimethoxysilane Comparative Example 3: Tris(trimethylsilyl)silane Comparative Example 4 Tetramethyl orthosilicate Comparative Example 5: Phenyltrimethoxysilane Comparative Example 6: Cyclohexyl dimethoxymethylsilane

[0134]

[0135] Experimental Example

[0136] Experimental Example 1: Total Acid Number (TAN)

[0137] A test composition for evaluating high-temperature stability according to the ASHRAE Standard 97 test method was prepared by mixing 100 parts by weight of CF3I as a refrigerant with 100 parts by weight of each refrigeration oil prepared according to the above-described examples and comparative examples. The high-temperature stability evaluation for each test composition was carried out as follows.

[0138] The above test composition was placed in a container (tube) along with a copper (Cu) catalyst, an aluminum (Al) catalyst, and an iron (Fe) catalyst, and sealed. Specifically, high-purity copper, aluminum alloy Al3003, and carbon steel were used as the Cu, Al, and Fe catalysts, respectively. Subsequently, the sealed container was stored in an environment where the temperature was controlled at approximately 150°C, and these high-temperature conditions were 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 the catalyst were continuously exposed to high temperatures during the stability evaluation period. Afterward, the sealed container was left at room temperature to cool, and the test composition was removed from the container.

[0139] CF3I was removed from the above test composition through vacuum and nitrogen bubbling. Specifically, CF3I was removed from the test composition through a two-step process including vacuum and nitrogen bubbling. First, volatile CF3I was separated from the refrigeration oil through vacuum. Subsequently, residual CF3I was further removed by passing nitrogen gas in the form of bubbles through the composition. Through this procedure, a purified refrigeration oil sample suitable for acid value measurement was obtained.

[0140] Subsequently, the total acid number (TAN) of the refrigeration oil from which CF3I had been removed was measured using a 686 Titroprocessor (Metrohm) in accordance with ASTM D664. A lower TAN value indicates higher oxidation stability of the refrigeration oil.

[0141]

[0142] The results are shown in Table 3 below.

[0143]

[0144] Experimental Example 2: ASTM Color Index

[0145] For each refrigeration oil prepared according to the above-described examples and comparative examples, a high-temperature stability evaluation was performed using the ASHRAE Standard 97 test method under the same method and conditions as in Experimental Example 1. Afterward, the sealed container was left at room temperature to cool, and the test composition was removed from the container.

[0146] CF3I was removed from the above test composition through vacuum and nitrogen bubbling. Specifically, CF3I was removed from the test composition through a two-step process including vacuum and nitrogen bubbling. First, volatile CF3I was separated from the refrigeration oil through vacuum. Subsequently, residual CF3I was further removed by passing nitrogen gas through the composition in the form of bubbles. Through this procedure, a purified refrigeration oil sample suitable for ASTM color index measurement was obtained.

[0147] Subsequently, the color index of the refrigeration oil from which CF3I had been removed was evaluated according to ASTM D1500 using a LICO 500 - Spectral colorimeter (HACH LANGE).

[0148] Specifically, each refrigeration oil was placed in a test tube and compared with a standard color glass to record the standard color number that matched best. If the color did not exactly match the standard value, a number closer to the darker side was selected.

[0149] The ASTM color index ranges from standard color numbers 0.5 to 8.0, and the less the color change, the higher the chemical stability of the refrigeration oil.

[0150]

[0151] The results are shown in Table 3 below.

[0152]

[0153] Temperature (°C) Acid Number (TAN) ASTM Color Index Example 1 1500 0.62 < 0.5 Example 2 1500 0.74 < 0.5 Example 3 1500 0.34 < 0.5 Example 4 1500 0.42 < 0.5 Example 5 1500 0.64 < 0.5 Comparative Example 1 150 67.5 > 8 Discoloration Comparative Example 2 150 Unable to measure due to precipitate formation > 8 Discoloration Comparative Example 3 150 Unable to measure due to precipitate formation > 8 Discoloration Comparative Example 4 150 84.7 > 8 Discoloration Comparative Example 5 150 4.39 < 0.5 Comparative Example 6 150 Unable to measure due to precipitate formation > 8 Discoloration

[0154]

[0155] Referring to Table 3, after evaluating high-temperature stability according to the ASHRAE Standard 97 test method, the refrigeration oil according to the examples had lower total acid number and ASTM color index compared to the refrigeration oil according to the comparative examples.

[0156] As in the comparative examples, three or more alkoxy groups are bonded to the Si of the silane compound, or the alkoxy group or C1-C 14 When the alkyl group was not bonded or the aminoalkyl group was bonded, a precipitate was formed or discoloration occurred after high-temperature stability evaluation according to the ASHRAE Standard 97 test method.

[0157] These experimental results show that the refrigeration oil according to the examples has improved high-temperature stability compared to the comparative example oil, resulting in reduced formation of acidic decomposition products and superior maintenance of appearance and chemical quality.

Claims

1. Refrigeration oil comprising a silane compound of the following chemical formula 1: [Chemical Formula 1] In the above 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 selected from C1-C 14 It is an alkyl group.

2. A refrigeration oil according to claim 1, wherein in the above chemical formula 1, any one or any two of R1 to R4 are each independently selected from a methoxy group or an ethoxy group.

3. A refrigeration oil according to claim 1, wherein in the above chemical formula 1, any one or two of the remainders are a methyl group, an ethyl group, or a propyl group.

4. A refrigeration oil according to claim 1, wherein any two of R1 to R4 in the above formula 1 are each independently selected from C1-C3 alkoxy groups, and the remaining two are each independently a C1-C2 linear alkyl group or a C3-C7 branched alkyl group.

5. The refrigeration oil according to claim 1, comprising 0.1% to 10% by weight of a silane compound of Formula 1 based on the total weight of the refrigeration oil.

6. Refrigeration base oil according to claim 1, further comprising at least one of base oil and additives.

7. In claim 6, the refrigeration base oil comprising 87% to 99% by weight of the base oil based on the total weight of the refrigeration base oil.

8. The refrigeration base 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. Refrigeration oil according to claim 6, wherein the additive comprises at least one of a stabilizer, an antioxidant, a corrosion inhibitor, an acid capture agent, an extreme pressure additive, and an anti-wear agent.

10. A refrigeration base oil according to claim 9, comprising the silane compound of Formula 1, the base oil, the stabilizer, the acid capture agent, and the anti-wear agent.

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

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

13. Refrigeration oil according to any one of paragraphs 1 to 12; and A composition for a refrigerator comprising a refrigerant including CF3I.

14. A composition for a refrigerator according to claim 13, wherein the refrigerant further comprises a refrigerant other than CF3I.

15. A heat pump comprising the refrigeration oil of any one of paragraphs 1 to 12.

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