• 제목/요약/키워드: Oil Miscibility Test

검색결과 6건 처리시간 0.018초

R-744/오일 혼합물의 상용성 및 증기압에 관한 실험적 연구 (An Experimental Study on Miscibility and Vapor Pressure of R-744/Oil Mixtures)

  • 최희성;강병하;박경근;김석현
    • 설비공학논문집
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    • 제16권2호
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    • pp.150-157
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    • 2004
  • Carbon dioxide ($CO_2$, R-744) has become a very popular issue in application to refrigeration and air conditioning systems as a natural refrigerant. An experimental study has been carried out to investigate miscibility and the vapor pressure of refrigerant R-744 in the presence of lubricant oil. This is of particular interest in the selection of the lubricant oil for the compressor of a refrigeration system or an air conditioning system using the refrigerant R-744. The experimental set-up consists of the equilibrium cell, measuring devices, the vacuum pump, the constant temperature bath and relevant connecting pipes made of stainless steel. Five lubricant oils, such as mineral oil (Naphthenic), AB (Alkyl Benzene) oil, PAO (Poly Alpha Olefin) oil, PAG (Poly Alkylene Glycol) oil and POE (Polyol Ester) oil are considered in the present study. Test runs were conducted with the oil concentration range from 5 to 50 wt%, and the temperature range from -10 to 1$0^{\circ}C$ with 2$^{\circ}C$ intervals. The miscibility results are visualized and correlated with the vapor pressure for the individual test components.

R-744/광유 및 POE 오일 혼합물의 증기압 및 상용성에 관한 연구 (Study on the Vapor Pressure and Miseibility of R-744/Mineral and POE Oil Mixture)

  • 최희성;김석현;박경근
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2003년도 춘계학술대회
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    • pp.1672-1677
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    • 2003
  • Carbon dioxide($CO_2$, R-744) has become a very popular issue in application to refrigeration and air conditioning systems as a natural refrigerant. An experimental study has been carried out to investigate the vapor pressure and miscibility of refrigerant R-744 in the presence of lubricant oil. This is of particular interest in the selection of the lubricant oil for the compressor of a refrigeration system or an air conditioning system using the refrigerant R-744. This apparatus consists of the test section, measuring devices, the vacuum pump, the constant temperature bath and relevant connecting pipes made of stainless steel. Two lubricant oils, such as mineral oil(Naphthenic) and polyol ester(POE) oil, are considered in the present study. For this purpose, test runs were conducted with the oil concentration range from 5 to 50 wt%, and the temperature range from -10 to $10^{\circ}C$ with $2^{\circ}C$ intervals. The results are correlated with the vapor pressure. and showed with the miscibility as visualization for the individual text components.

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대체냉매 R436B를 적용한 정수기 냉각수 시스템 신뢰성 평가에 관한 연구 (A Study on the Reliability of Cooling Water Systems Using R436B)

  • 남현규;배상은;배철호;고정수;진병주;오주철
    • 설비공학논문집
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    • 제25권8호
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    • pp.438-442
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    • 2013
  • The alternative refrigerant R436B is applied, to assess the application feasibility for a commercial cooling water system. The characteristic stability was verified by Sealed glass tube test and Autoclave test. R436B is chemically stable with the compressor material. The Oil miscibility test shows the usual compressor oil mixed well with R436B. Through the life acceleration test, the cooling performance is maintained. Though slight changes in oil and capillary tube diameter were found, they were within the permitted range. R436B should be applied to commercial cooling water systems as a simple replacement for the usual refrigerant.

R-134a 냉매용 냉동기유 선정을 위한 기초 연구 (A Basic Study on Selection of Refrigeration Oils for R-134a Refrigerant)

  • 나병철;안영재;한동철;전경진
    • 설비공학논문집
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    • 제6권4호
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    • pp.439-452
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    • 1994
  • One of the chlorofluorocarbon compounds. R-12 deplete atmospheric ozone. It leads to international agreement to reduce CFC production. R-134a has similar thermodynamic properties to CFC-12. It has zero ODP(Ozone Depletion Potential). This Paper focuses on the lubricating oils for using with R-134a PAGs(Polyalkylene Glycol's) and esters are primary lubricants that are now being tested for use with R-134a Because of extreme polarity of R-134a. there are many problems in the selection of lubricating oil. This investigation analyzes compressor working conditions and calculates wear parts friction for simulation testing. Miscibility and material compatibility is proved by sealed glass tests. Friction was tested on the closed type pin on disk wear tester. This equipment simulates actual refrigerating compressor. Environment controlled test made more reliable result than field test Conventional oils(mineral oils, Alkylbenzene, PAO(Polyalpha Olefin) are immiscible with R-134a. PAGs and ester oils are miscible with R-134a. Friction coefficient is similar to conventional system(mineral oil/R-12 systems) at operating condition. At start & stop condition, PAGs/R-134a system has high friction coefficient. It provide reliable result on the lubricity, miscibility, material compatibility of R-134a with these new lubricants. It suggests proper selection of refrigeration oil that may improve compressor durability of performance.

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냉동기유 주입량과 냉매 충진량에 따른 냉동기 성능 평가 (Effects of Refrigerant and Oil Charges on the Performance of an Refrigeration System)

  • 선종관;채수남;정동수
    • 설비공학논문집
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    • 제14권8호
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    • pp.617-625
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    • 2002
  • In this study, effects of refrigerant and oil charges on the performance of a refrigeration system simulating an automobile air conditioner have been experimentally investigated using R134a and PAG oil. Measurements were taken in a breadboard type refrigeration test unit with a compressor used for a commercial automobile air-conditioner under a set of condition imposed upon normally to automobile air conditioners. Both the COP and capacity decreased rapidly as the oil charge increased because of the decrease in vapor pressure of the circulating refrigerant/oil mixture. The excess oil left in the evaporator also caused heat transfer degradation resulting in a decrease in capacity and in turn COP. It was found that there is an optimum refrigerant charge at which the COP becomes the maximum. Below this optimum charge, both the capacity and COP increased as the refrigerant charge increased and above the optimum charge, both of them remained almost constant. Hence, the COP seems to be the most important factor in determining the optimum refrigerant charge. When the system was undercharged, the refrigerant at the condenser exit lost subcooling and showed a sign of poor miscibility.

대체냉매를 사용한 에어콘에서 합성오일과 건조제(M/S)의 영향 (Effects of Refrigerant Oils and Molecular Sieve on Air Conditioner using Alternative Refrigerant)

  • 좌성훈;홍정기;김창국;윤백;강석춘
    • 설비공학논문집
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    • 제8권4호
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    • pp.473-483
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    • 1996
  • To protect the ozone layer, R22 will be replaced with HFCs. R407C is a leading candidate as alternative refrigerant for air conditioner due to its similar thermodynamic characteristics with R22. In replacing R22 with R407C, the compatibility with lubricating oil is of major concern. Polyol ester (POE) oil among the synthetic oils is considered to be the best lubricant for use with R407C because of good electrical properties and miscibility. However, lubricating ability of mixture of R407C/POE oil is lower than that of R22/mineral oil due to the production of acid by hydrolysis which causes corrosive wear. Therefore, to minimize water content, it is needed to develop a molecular sieve desiccant which is compatible with R407C and ester oil. This paper discusses (1) the change of properties of POE oil when current molecular seive is used, (2) the effects of POE oils and additives on durability of compressor. Through compressor life test and bench wear test, it was found that inadequate use of POE oils and additives may promote the deteriation of molecular sieve, resulting in decrease of durability of compressor.

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