KR20000036953A - Composition of hydrocarbon refrigerant mixtures for alternating of refrigerant R-12 and R-22 - Google Patents

Abstract

PURPOSE: A hydrocarbon-based refrigerant mixture composition is provided, which can replace the freon-typed refrigerant R-12 and R-13 without the modification of the structure of cooler system. CONSTITUTION: A composition comprises 25-35 wt.% of at least one refrigerant gas selected from hydrocarbon-based refrigerant gases; 65-75 wt.% of at least one refrigerant gas selected from HFC-based refrigerant gases; and 2-5 wt.% of a silicone oil for inhibiting the flammability of the refrigerant gases. Preferably the hydrocarbon-based refrigerant gas is isobutane, and the HFC-based refrigerant gas is difluoroethane. Also the composition comprises at least two refrigerant gases selected from hydrocarbon-based refrigerant gases; and a silicone oil. Preferably the hydrocarbon-based gas is the mixture of propane and propylene. The silicone oil is dimethyl polysiloxy acid.

Description

Composition of hydrocarbon refrigerant mixtures for alternating of refrigerant R-12 and R-22}

The present invention relates to a refrigerant composition used in a refrigerator, and more particularly, to a hydrocarbon-based mixture of at least one hydrocarbon-based refrigerant and at least one HFC-based refrigerant mixture, which are environmentally friendly, which minimizes the impact on global ozone depletion and global warming potential. A refrigerant composition comprising a silicone oil for flame retardant of a refrigerant.

Typically, a freezer has a refrigeration cycle consisting of a compressor, a condenser, an evaporator, a receiver, an oil separator, a liquid separator, etc. The freezer absorbs heat from a low heat source and moves it to a high temperature. The refrigerant used in the refrigerating cycle is evaporated at low temperature in the evaporator to absorb the surrounding heat, compressed by high-temperature and high-pressure gas in the compressor, cooled in the condenser, and then changed back into liquid refrigerant. It is reduced in pressure through the expansion valve and evaporates in the evaporator, thereby circulating inside the freezer cycle and continuously freezing.

Representative refrigerants are carbonized compounds including ammonia, carbon dioxide, and fluorine, which are freon-based gases R-11, R-12, R-13, R-21, R-22, R-114 R-500 and R-. 502, propane, etc. are used.

In the Freon system, R-12 is mainly used in relatively small refrigerators such as automobile air conditioners and household electric refrigerators. R-22 is mainly used in home and industrial air conditioners because it has a larger freezing capacity per unit volume than R-12. have. R-113 and R-114 are mainly used in turbo chillers. R-500 and R502 are used as an azeotrope mixed refrigerant which acts as if it is one kind of refrigerant even if two kinds of refrigerants are mixed.

However, ammonia is excellent in refrigerant characteristics such as refrigeration capacity, but is toxic gas, flammable and explosive, and corrodes copper and copper alloys when air and moisture invade. On the other hand, freon refrigerant has excellent refrigerant characteristics such as refrigeration capacity. No toxicity, flammability, metal corrosion and no toxic to human body, but freon gas ), And certain freons R-11, R-12, R-113, R-114, and R-115 were regulated. Therefore, the mixed refrigerant containing all the CFC & HCFC refrigerants and CFC & HCFC refrigerants cannot be used in the future.

On the other hand, refrigeration oil is used as a lubricating oil to protect a compressor from abrasion. The refrigeration oil is required to have excellent lubrication characteristics at low temperatures and to coexist stably with a refrigerant. In this case, the refrigeration oil dissolves the refrigerant oil and the liquid refrigerant up to a certain temperature. In a freon-type freezer, the refrigeration oil is ejected from the compressor and circulated inside the cycle to be returned to the compressor case. In the case of using a compressor which requires a large amount of oil, and a long distance of a refrigerant circulation cycle, an oil separator is used.

Among these, various kinds of freon substitutes have been proposed, but as a substitute, hydrofluorocarbon-based (hereinafter referred to as “HFC-based” for convenience). Even refrigerants (R-134a, R407C, and R-410A) are refrigerant systems including compressors and manufacturing facilities. It is impossible to apply immediately without supplementation.

As a refrigerant other than a freon system, for example, a household refrigerator using isobutane as a refrigerant has been proposed, but there are problems in terms of low freezing capacity per unit volume, flammability, and explosiveness. On the other hand, air conditioners using propane as a refrigerant have been proposed, but this also has problems in terms of low freezing capacity per unit volume, flammability, and explosiveness. And in the condensation process, the temperature gradient appears to be about 5 to 6 ℃ large, there is a problem in terms of flammability, explosive.

In conclusion, none of them have a feature that can be completely replaced immediately by adjusting the amount of refrigerant without changing the design of a refrigerator system using an existing Freon refrigerant.

Japanese Patent Application Laid-open No. Hei 5-339563 proposes a refrigerant flame-retardant by adding silicon to LPG or a refrigerant in which alcohol, LPG, propane, butane and aqueous silicon are added. However, these refrigerants cannot be used in refrigerators using freon-based refrigerants such as domestic refrigerators and air conditioners due to reliability problems such as corrosion and power consumption of the compressor. In addition, if these proposed new refrigerants are used, it is necessary to change the design of the compressor of the refrigerator from the basics. This design change is costly and waste of resources. Not only is it difficult to effectively apply existing automobile air conditioners and refrigerators using freon-based refrigerants, but the cost of modifying their production equipment is enormous.

The present invention has been made to solve the above-mentioned conventional problems, an object of the present invention is to provide a composition of a hydrocarbon-based mixed refrigerant which is an alternative to the Freon-based refrigerant which is the main culprit of ozone layer destruction and warming.

Another object of the present invention is to provide a hydrocarbon-based mixed refrigerant composition that can be immediately applied only by adjusting the amount of refrigerant without changing the design of a refrigerator system using an existing Freon-based refrigerant.

It is another object of the present invention to provide a composition of a hydrocarbon-based mixed refrigerant which minimizes a temperature gradient in the evaporation and condensation process of a general mixed refrigerant.

Another object of the present invention is to provide a composition of a hydrocarbon-based mixed refrigerant containing an additive for improving the flammability of the hydrocarbon-based refrigerant.

In order to achieve the above object, the present invention,

In the refrigerant composition used in the low temperature freezer,

At least one refrigerant gas selected from hydrocarbon refrigerant gas, at least one refrigerant gas selected from HFC refrigerant gas, and silicone oil added to suppress flammability of the hydrocarbon refrigerant gas. It provides a mixed refrigerant composition characterized in.

Preferably, the hydrocarbon-based refrigerant gas is made of isobutane [R-600a, C ₄ H ₁₀ ], the HFC-based refrigerant gas is difluoroethane [R-152a, CHF ₂ -CH ₃ ], The silicone oil is made of dimethylpolyshirokisan.

In contrast, the present invention,

In the refrigerant composition used in the high temperature freezer,

Provided is a mixed refrigerant composition comprising at least two or more refrigerant gases selected from hydrocarbon refrigerant gases and silicone oils added to suppress the flammability of the hydrocarbon refrigerant gases.

Preferably, the hydrocarbon-based refrigerant gas is made of propane [R-290, C ₃ H ₈ ] and propylene (R-1270, CH ₃ -CH-CH ₂ ], the silicone oil is It consists of dimethylpolyshirokisan.

Hereinafter, the hydrocarbon-based mixed refrigerant composition according to the present invention will be described in detail.

The present invention is a breakthrough of the reality that the use of the existing CFC and HCFC refrigerants are regulated due to the problem of the destruction of the environment, and the refrigerant amount is adjusted only without changing the design of the refrigerator system using the existing freon refrigerant. It is to develop a hydrocarbon-based mixed refrigerant composition and a method for producing the same immediately applicable.

In addition, the present invention has been developed a composition of a hydrocarbon-based mixed refrigerant and a method of manufacturing the same to minimize the temperature gradient in the evaporation and condensation process of the common mixed refrigerant.

In addition, a composition of a hydrocarbon-based mixed refrigerant including an additive for improving the flammability of the hydrocarbon-based refrigerant and a method of manufacturing the same have been developed.

<First embodiment>

The first refrigerant composition manufactured according to the first embodiment of the present invention is a refrigerant composition used in a low temperature freezer such as a refrigerator, a car, an air conditioner, etc., which is composed of a compressor, a condenser, a receiver, an expansion valve, an evaporator, and the like. A refrigerant composition comprising a mixture of at least one refrigerant gas selected from the group consisting of at least one refrigerant gas and at least one refrigerant gas selected from the HFC system, and a silicone oil for flame retarding the preceding refrigerant gas.

The preceding refrigerator uses a freon refrigerant, and may be any conventional compressor such as a reciprocating, rotary, screw, or scroll compressor. In particular, when the refrigerant composition of the present invention is used in a refrigerator using a freon-based refrigerant, it can be applied immediately without changing the design of a conventional compressor or the like constituting the refrigerator.

In addition, any of the above-mentioned freezers having any oil separator, liquid separator, or the like, in addition to the above-mentioned apparatuses are not impeded, and preferably, these apparatuses are provided.

Refrigerator oil can be used singly or in combination with standard products (ISO VG 10-100) set by the International Organization for Standardization (ISO), and in particular, there is no problem in using mineral oil mainly used in existing refrigerator systems. There is no.

The refrigeration unit compresses the refrigerant gas evaporated in the low temperature evaporator and sends it to the condenser as a high temperature gas. In this refrigeration cycle, the amount of heat discarded by the condenser is much higher than that of the electric heater. Economical.

The refrigerant composition of the present invention is also applicable to a heat pump type refrigerator. The refrigerant composition is cooled by cooling the air in an evaporator in the outdoors, and warming the air in a condenser in the room. The present invention can also be applied to heat pump air conditioners and the like which can both heat and heat.

What is necessary is just to select the refrigerant gas which is easy to obtain industrially. Depending on the required refrigeration capacity, the type of freezer, the operating temperature, etc., a plurality of refrigerant gases are mixed and used. Preferably, it is selected as a selection criterion such as being non-reactive, easy to obtain industrially, and low price.

The preceding hydrocarbon refrigerant gas is isobutane [R-600a] having a general formula C _n H _{2n + 2} and having a carbon number n of 1 methane, 2 ethane, 3 propane and 4 butane. , C ₄ H ₁₀ ]. HFC refrigerant gas uses difluoroethane [R-152a, CHF ₂ -CH ₃ ].

The silicone oil used in the present invention is used to flame-retard the preceding hydrocarbon-based refrigerant gas, and is silicone which is oily at room temperature.Silicone oil has a low viscosity rate change due to temperature and a low freezing point. It is known to be chemically inert, has low surface tension, has anti-foaming effect, and has good electrical insulation, but it is not known that the refrigerant gas is flame retardant when this silicone oil is added to the preceding refrigerant gas. In particular, by adding silicone oil, hydrocarbons do not explode even when ignited, and can be safely used as a refrigerant in household refrigerators.

Preferably, a silicone oil having a dimethylpolysiloxy acid structure having the following structure, which is a kind of straight silicone oil, is preferable. This silicone oil is a synthetic oil which does not exist in nature, and uses an inorganic sirokilic acid bond (Si-O-Si) such as glass or quartz, which is resistant to heat, and an organic methyl group, preferably having a viscosity of 0.65 to 10. {cst} is also preferable, and methylphenyl silicone oil in which a part of the methyl group of dimethyl silicone oil is substituted with a phenyl group, or methyl hydrogen silicone oil in which a part of the methyl group of the dimethyl silicone oil is replaced with hydrogen.

In addition, organic groups are introduced into the polycyclic chains (both rings) known as modified silicone oils, organic groups are introduced at both ends of the polyshirokisan, and organic groups are introduced at one end of the polyshirokisan. Various modified silicone oils having a structure such as introducing organic groups into both rings of the Rocky Mountain and the sock end may be used.

The first refrigerant composition of the present invention is produced by the following method.

Remove the air in the sealed container with a vacuum pump as much as possible and bring it to a vacuum. At least one refrigerant selected from hydrocarbons and at least one refrigerant gas selected from HFC refrigerants is injected into the sealed container. Then, the silicone oil is added to the inside of the vessel and stirred for a predetermined time to complete the refrigerant composition. The preparation thereof is performed at room temperature.

The first refrigerant composition according to the first embodiment of the present invention is _{25 to} 35 wt% of isobutane [C ₄ H ₁₀ ], which is a hydrocarbon refrigerant gas, and difluoroethane [HFC], which is a refrigerant gas. CHF ₂ -CH ₃ ] is added by adding 2 to 5% by weight of silicone oil in addition to 65 to 75% by weight.

<Second embodiment>

The second refrigerant composition manufactured according to the second embodiment of the present invention is a refrigerant composition used in a high temperature freezer such as a home and industrial air conditioner composed of a compressor, a condenser, a receiver, an expansion valve, an evaporator, and the like. It is a refrigerant composition which consists of a silicone oil for flame retarding the preceding refrigerant gas as a mixture of at least 2 types of refrigerant gases chosen.

The preceding refrigerator uses a freon refrigerant, and may be any conventional compressor such as a reciprocating, rotary, screw, or scroll compressor. In particular, when the refrigerant composition of the present invention is used in a refrigerator using a freon-based refrigerant, it can be applied immediately without changing the design of a conventional compressor or the like constituting the refrigerator.

In addition, any of the above-mentioned freezers having any oil separator, liquid separator, or the like, in addition to the above-mentioned apparatuses are not impeded, and preferably, these apparatuses are provided.

Refrigerator oil can be used singly or in combination with standard products (ISO VG 10-100) set by the International Organization for Standardization (ISO), and in particular, there is no problem in using mineral oil mainly used in existing refrigerator systems. There is no.

The refrigeration unit compresses the refrigerant gas evaporated in the low temperature evaporator and sends it to the condenser as a high temperature gas. In this refrigeration cycle, the amount of heat discarded by the condenser is much higher than that of the electric heater. Economical.

The refrigerant composition of the present invention is also applicable to a heat pump type refrigerator. The refrigerant composition is cooled by cooling the air in an evaporator in the outdoors, and warming the air in a condenser in the room. The present invention can also be applied to heat pump air conditioners and the like which can both heat and heat.

What is necessary is just to select the refrigerant gas which is easy to obtain industrially. Depending on the required refrigeration capacity, the type of freezer, the operating temperature, etc., a plurality of refrigerant gases are mixed and used. Preferably, it is selected as a selection criterion such as being non-reactive, easy to obtain industrially, and low price.

The above hydrocarbon-based refrigerant gas has a general formula C _n H _{2n + 2} , and has a propane [R-290, among methane, n-ethane, 2-propane, 4-butane, n-carbon number 1; C ₃ H ₈ ] and propylene [R-1270, CH ₃ -CH-CH ₂ ] are used.

The silicone oil used in the present invention is used to flame-retard the preceding hydrocarbon-based refrigerant gas, and is silicone which is oily at room temperature.Silicone oil has a low viscosity rate change due to temperature and a low freezing point. It is known to be chemically inert, has low surface tension, has anti-foaming effect, and has good electrical insulation, but it is not known that the refrigerant gas is flame retardant when this silicone oil is added to the preceding refrigerant gas. In particular, by adding silicone oil, hydrocarbons do not explode even when ignited, and can be safely used as a refrigerant in household refrigerators.

Preferably, a silicone oil having a dimethylpolysiloxy acid structure having the following structure, which is a kind of straight silicone oil, is preferable. This silicone oil is a synthetic oil which does not exist in nature, and uses an inorganic sirokilic acid bond (Si-O-Si) such as glass or quartz, which is resistant to heat, and an organic methyl group, preferably having a viscosity of 0.65 to 10. {cst} is also preferable, and methylphenyl silicone oil in which a part of the methyl group of dimethyl silicone oil is substituted with a phenyl group, or methyl hydrogen silicone oil in which a part of the methyl group of the dimethyl silicone oil is replaced with hydrogen.

In addition, organic groups are introduced into the polycyclic chains (both rings) known as modified silicone oils, organic groups are introduced at both ends of the polyshirokisan, and organic groups are introduced at one end of the polyshirokisan. Various modified silicone oils having a structure such as introducing organic groups into both rings of the Rocky Mountain and the sock end may be used.

The second refrigerant composition according to the second embodiment of the present invention is produced by the following method.

Remove the air in the sealed container with a vacuum pump as much as possible and bring it to a vacuum. At least two or more refrigerant gases selected from hydrocarbons are injected into the sealed container. Then, the silicone oil is added to the inside of the vessel and stirred for a predetermined time to complete the refrigerant composition. The preparation thereof is performed at room temperature.

The second refrigerant composition of the present invention is a hydrocarbon-based refrigerant in addition to 35 to 45% by weight of propane [C ₃ H ₈ ], 55 to 65% by weight of propylene [CH ₃ -CH-CH ₂ ] In order to improve the flammability which it has, it consists of adding 2-5 weight% of silicone oil as an additive.

Experimental Results and Discussion

Table 1 shows the experimental results of the performance evaluation of the first refrigerant composition using the hermetic compressor used in the home refrigerator, Table 2 below shows the performance evaluation results of the second refrigerant composition using the hermetic compressor used for the domestic and industrial air conditioner Indicated. The experimental apparatus used the second refrigerant calorimetry of the Korean Industrial Standard (KS B 6365-1987), and the measurement conditions were the US ASHRAE standard conditions.

Table 1. Results of calorimeter test for ASHRAE LBP application

Table 2. Results of calorimeter test for ASHRAE HBP application

The experimental results of Table 1 show that the first refrigerant composition has a superior refrigerating capacity and performance coefficient than the conventional R-12 refrigerant, and the experimental results of Table 2 indicate that the second refrigerant composition is a conventional R-22 refrigerant. And the freezing capacity and coefficient of performance are similar.

Tables 3 and 4 show the results of the reliability test using the rotary compressor used in the home air conditioner.

Table 3. Results of heavy load life test for ASHRAE LBP compressor

RefrigerantComporOil Item R12 R-134a First refrigerant composition (CX-12a) PL25 Freol S-22T Wear No No No Ref.Oil Color (ASTM) L0.5 L0.5 L0.5 TAN (0.1 ↓) (mgKOH / g) 0.008 0.010 0.009 Water (20ppm ↓) 0 0 0

Table 4. Results of heavy load life test for ASHRAE HBP compressor

RefrigerantComporOil Item R22 R-407C Second refrigerant composition (JS-22a) 44A056IV1 SUNISO-4GS Wear No No No Ref.Oil Color (ASTM) L0.5 L0.5 L0.5 TAN (0.1 ↓) (mgKOH / g) 0.007 0.012 0.005 Water (20ppm ↓) 0 5 0

The overload test results of Tables 3 and 4 performed by applying various refrigerant oils and refrigerants to hermetic reciprocating and rotary compressors used in domestic refrigerators and air conditioners are based on the first refrigerant composition (CX-12a) and the second refrigerant composition ( JS-22a) both show very good reliability compared to R12 and R22.

As mentioned above, in the case of using the hydrocarbon-based mixed refrigerant proposed in the present invention, CFC and HCFC-based refrigerants (R-12, R-22), which are regulated as global environmental destruction substances by the Montreal Protocol, can be used. It can be applied immediately by adjusting the amount of refrigerant without changing the design of the refrigerator system using the existing R-12 and R-22. Therefore, it is also effective to improve the manufacturing cost of the refrigerator product because it is not necessary to supplement the existing refrigerator production equipment.

Looking at the function as a refrigerant of the hydrocarbon-based mixed refrigerant composition according to the present invention, the evaporation temperature at atmospheric pressure is low, the condensation and evaporation pressure is equivalent to that of R-12 and R-22. And, the latent heat of evaporation is excellent, the freezing point is low, and the volume freezing capacity is excellent. In addition, the critical temperature is high, there is no chemical reactivity with the refrigeration oil, the viscosity is small and the heat transfer action is high. In addition, it is electrically insulating and does not corrode the electrical insulating material. In addition, it has significantly improved the flammability and explosiveness, is harmless to the environment and the human body, and can be applied immediately by adjusting the amount of refrigerant without the need to improve the refrigerator as it is.

Although the above has been described with reference to a preferred embodiment of the present invention, those skilled in the art will be able to variously modify and change the present invention without departing from the spirit and scope of the invention as set forth in the claims below. It will be appreciated.

Claims (6)

In the refrigerant composition used in the low temperature freezer, At least one refrigerant gas selected from hydrocarbon refrigerant gas, at least one refrigerant gas selected from HFC refrigerant gas, and silicone oil added to suppress flammability of the hydrocarbon refrigerant gas. Mixed refrigerant composition characterized in that. The method of claim 1, wherein the hydrocarbon-based refrigerant gas is isobutane (R-600a, C ₄ H ₁₀ ), the HFC-based refrigerant gas is difluoroethane (R-152a, CHF ₂ -CH ₃ ] mixed refrigerant composition characterized in that consisting of. The mixed refrigerant composition according to claim 1 or 2, wherein the silicone oil is made of dimethylpolyshirokisan. In the refrigerant composition used in the high temperature freezer, A mixed refrigerant composition comprising at least two or more refrigerant gases selected from hydrocarbon refrigerant gases and silicone oils added to suppress flammability of the hydrocarbon refrigerant gases. The method of claim 4, wherein the hydrocarbon-based refrigerant gas is characterized in that the propane (propane) [R-290, C ₃ H ₈ ] and propylene (propylene) [R-1270, CH ₃ -CH-CH ₂ ] Mixed refrigerant composition. The mixed refrigerant composition according to claim 4 or 5, wherein the silicone oil is made of dimethylpolyshirokisan.