• Title/Summary/Keyword: 냉매 134a

Search Result 202, Processing Time 0.029 seconds

자동차용 냉매가 환경에 미치는 영향

  • 김영일
    • The Magazine of the Society of Air-Conditioning and Refrigerating Engineers of Korea
    • /
    • v.29 no.9
    • /
    • pp.75-78
    • /
    • 2000
  • 환경친화적 자동차에 대한 관심이 커질수록 여러 분야에서 시스템 설계의 영향을 더욱 더 잘 이해하려는 노력이 진행되고 있다. 자동차용 냉방기의 경우 냉방시스템의 세밀한 분석과 환경에 미치는 영향을 최소화하기 위한 설계가 이루어지고 있다. 그 중에서도 냉매의 선택과 그 냉매의 환경적 영향에 대한 자세한 연구가 필요하다. 몬트리올 조약 이후 자동차 산업계는 대부분 R-134a를 채택하고 있는데 이는 R-134a가 오존층을 파괴하지 않을 뿐 아니라 적절한 사이클 효율을 가지면서 안전하고 비독성이며 불연성이기 때문이었다. 최근 지구온난화와 이산화탄소($CO_2$)의 발생원에 대한 관심은 산업계가 사용냉매를 재검토하게 하는 계기가 되었으며, R-134a도 교토 조약의 규제냉매에 속해 있어 자동차용 냉방기의 대체냉매에 대한 연구가 시급하다고 여겨지고 있다. R-134a와 관련된 주된 논점은 냉매 누설시의 영향이다. R-134a의 지구온난화지수(GWP)는 1,300인데, 이는 누출되었을 때 1,300배의 이산화탄소가 누출된 것과 동일하다는 것을 의미하다. 최근 자연냉매의 선호와 맞물려 냉매로서 이산화탄소의 평가에 많은 관심이 모아지고 있다. 본 글에서 자동차용 냉방기의 대체냉매로서 이산화탄소의 상대적인 장점과 R-134a와의 비교에 대해 수행된 연구결과를 나타내었다.

  • PDF

Destruction of HFC-134a Refrigerant in Gasification-melting Demonstration System (가스화용융(熔融) 실증 시스템에서 HFC-134a 냉매분해(冷媒分解) 특성(特性) 연구(硏究))

  • Jung, Dae Sung;Hong, Byeong Kwon;Kim, Woo Hyun;Roh, Seon Ah
    • Resources Recycling
    • /
    • v.21 no.4
    • /
    • pp.69-75
    • /
    • 2012
  • Destruction of HFC-134a from ELV (End of Life Vehicle) were determined in a gasification-melting demonstration system of municipal solid waste (100ton/day). The injection system has been developed for the uniform injection of HFC-134a to the gasification-melting system. The destruction characteristics of HFC-134a and analysis of exhaust gases have been performed. The destruction efficiency was 99.995% for HFC-134a feeding of 3 kg/hr and the exhaust gases such as CO, SOx, NOx, HCl and HF satisfied the environmental standards.

Computer Simulation Study for Analyzing Alternative Refrigerants in Residential Air-conditioners (가정용 냉방기의 대체 냉매 성능 분석을 위한 전산 해석 연구)

  • Yoo, Hwaan-Kyu;Jung, Dong-Soo
    • Solar Energy
    • /
    • v.15 no.3
    • /
    • pp.75-90
    • /
    • 1995
  • This paper is concerned about alternative refrigerants for HCFC22 used in room air conditioners and heat pumps. Computer simulation of residential air conditioners using refrigerant mixtures is carried out. Following refrigerants are selected as the pure refrigerants constituting the mixtures studied: R32, R124, R125, R134, R134a, R143a and R152a. Simulation results are presented fur the following mixtures: R32/R134a, R32/R152a, R32/R134, R32/R124, R143a/R134a, R143a/R152a, R143a/R124, R125/R134a, R125/R152a, R125/R124, R32/R152a/R134a, R32/R152a/R134, R32/R152a/R124. The best fluid is found to be the ternary mixture of R32/R152a/R124. For that mixture, the coefficient of performance(COP) and volumetric capacity for refrigeration(VCR) are 13.7% larger and 23% smaller than the respective values for HCFC22. R32/R124 mixture is the best binary fluid pair whose COP and VCR are 13.4% larger and 9.6% smaller than those for HCFC22.

  • PDF

Simulation of the flow characteristics of R1234yf flowing through capillary tubes (냉매 R1234yf의 모세관내 유동 특성에 관한 해석적 연구)

  • Kim, Daeyeong;Park, Chasik
    • Journal of the Korea Academia-Industrial cooperation Society
    • /
    • v.15 no.11
    • /
    • pp.6452-6457
    • /
    • 2014
  • R1234yf has been developed as an alternative refrigerant to R134a, which has been associated with global warming. The capillary tubes as expansion valves control the mass flow rate and balance system pressure in the refrigeration cycle. The present numerical model used the governing equations including the law of conservation of mass, momentum, and energy in a capillary tube. The mass flow rate of R1234yf decreased by 47.0% as the capillary tube length was increased from 1 to 4 m. As the inner diameter of the capillary tubes was changed from 1.3 to 1.7 mm, the mass flow rate of R134a and R1234yf increased by 117.9% and 121.0%, respectively. The mass flow rate of the R134a and R1234yf increased by 28.3% and 29.1% with subcooling increasing from 0 to $7^{\circ}C$. In addition, when the inlet temperature of the capillary tubes was changed from 35 to $60^{\circ}C$, the mass flow rate of R134a and R1234yf increased by 31.0% and 45.4%, respectively.

Estimation of Fugitive Emission Factors of HFC-134a from Scrap Cold Drinking Vending Machine at Use- and Disposal-Phase (음료용 폐자동판매기에서의 HFC-134a 사용 및 폐기단계 탈루배출계수 결정에 대한 연구)

  • Lee, Youngphyo;Kim, Eui-Kun;Kim, Seungdo;Byun, Seokho;Kim, Hyerim;Park, Junho;Lee, Dongwon
    • Journal of Korean Society of Environmental Engineers
    • /
    • v.35 no.5
    • /
    • pp.350-355
    • /
    • 2013
  • Little information is available for emission pathway even if HFC-134a that is known as one of the major greenhouse gases has been broadly used in Korea. This paper attempts to clarify the emission characteristics of HFC-134a used for refrigerant of cold drinking vending machines (CDVMs) at the use- and disposal-phase. We measured the residual amounts in the scrap CDVMs of 47 by applying commercial recover for refrigerant. The first-order kinetic model was introduced and the emission rate would be proportional to the remaining quantity of refrigerant. The emission factor at the use-phase was determined indirectly to be $6.9{\pm}0.7$ %/yr within a confidence interval of 95%, using information on residual amount and elapsed operation time at the disposal point. Correspondingly, the annual emission rate of HFC-134a per CDVM was determined to be 11.6 g. The average residual rate of HFC-134a in scrap CDVMs was assessed to be $62.5{\pm}2.2%$, leading to a potential emission amount of 144.8 g per scrap CDVM. The chemical compositions of refrigerants from scrap passenger vehicles are quite similar to those of new refrigerants, suggesting that the refrigerants from scrap passenger vehicles could be reused. During the recovering process of refrigerant, the recovered refrigerant was contaminated by compressor lubricant that accounted for about 30% in weight. It is necessary to separate the refrigerant from the recovered material contaminated by lubricant for recycling and reuse the refrigerant.

Measurement of R-134a Leakage from Vehicle Equipped Mobile Air Conditioning(MAC) System (실차를 이용한 자동차 에어컨 냉매 누출량 평가)

  • Kim, Ji Young;Seo, Chungyoul;Lee, Sangeun;Kim, Jeongsoo
    • Journal of Climate Change Research
    • /
    • v.3 no.2
    • /
    • pp.153-159
    • /
    • 2012
  • CFC-12 used in mobile air conditioning(MAC) system has been replaced by R-134a, a type of HFC refrigerant, from 1991 to 1994. R-134a has since been widely used as a refrigerant of a mobile air conditioner. However, it is one of the six main green house gases listed in Kyoto Protocol, which makes it imperative to regulate its emission and develop alternative refrigerants. In this study, the concentration of leaked R-134a was measured using VT(Variable Temperature) shed and Running loss test shed to analyze the level of air conditioner refrigerant leaked in a vehicle. According to the analysis of the concentration of R-134a leaked from a vehicle parked, annual leakage amount of R-134a was in the range of 6.46~13.28 g/yr. The figure was similar with the leakage from the mobile air conditioning system currently used. In a study using the same vehicle model, a vehicle equipped with dual evaporation system had a higher leakage rate of refrigerant than a vehicle with a single evaporation system. It appears that the added fittings and joints of the dual evaporator system led to higher leakage rate. Besides, the analysis of the change in R-134a concentration under various car speed found that more refrigerant leaked under high speed(100km/hr) and but the volume of the wind did not affect to the variation of refrigerant leakage.

Performance Comparison of Fin-Tube Type Evaporator using R134a and R1234yf under the Frost Condition (착상조건에서 R134a와 R1234yf를 적용한 핀-관 형태의 증발기 성능 비교)

  • Shin, Yunchan;Kim, Jinhyun;Cho, Honghuyn
    • Journal of the Korea Academia-Industrial cooperation Society
    • /
    • v.16 no.9
    • /
    • pp.5795-5801
    • /
    • 2015
  • The low temperature distribution of the refrigerated and frozen food has been increased gradually. Refrigeration industry is using R134a refrigerant, which GWP is 1300. R1234yf is an alternative refrigerant of R134a because GWP of R1234yf refrigerant is just 4. Evaporator used in refrigeration truck refrigeration system is operated on low temperature condition. Accordingly, evaporator is formed frost and the formation of frost is rapidly decreased performance of evaporator. In this study, the performance of evaporator using R134a and R1234yf refrigerant was analyzed with operating conditions under frost condition. As a result, the performance of R134a evaporator according to air inlet temperature, relative humidity and evaporating temperature was more sensitive than R1234yf evaporator. Besides, the frost growth of R134a evaporator is steeper than that of R1234yf one.

External Condensation Heat Transfer Coefficients of R1234yf (신냉매 R1234yf의 외부 응축 열전달계수)

  • Park, Ki-Jung;Lee, Cheol-Hee;Kang, Dong-Gyu;Jung, Dong-Soo
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
    • /
    • v.22 no.6
    • /
    • pp.345-352
    • /
    • 2010
  • In this study, external condensation heat transfer coefficients(HTCs) of R134a and R1234yf are measured on a plain, low fin, and Turbo-C tubes at the saturated vapor temperature of $39^{\circ}C$ with the wall subcooling of $3{\sim}8^{\circ}C$. R1234yf is a new alternative refrigerant of low greenhouse warming potential for replacing R134a which is one of the greenhouse gases controlled by Kyoto protocol and is used extensively in mobile air-conditioners. Test results show that the external condensation HTCs of R1234yf are very similar to those of R134a for all three surfaces tested. For the application of condensation heat transfer correlations to the design of condensers charged with R1234yf, thorough property measurements are needed for R1234yf in the near future.

Studies on the Performance of a Cam Driving Electronic Expansion Valve for Vehicles (캠구동 방식을 적용한 자동차 공조시스템용 전자팽창밸브의 성능에 관한 연구)

  • Kim, Sung Chul
    • Journal of the Korea Academia-Industrial cooperation Society
    • /
    • v.17 no.9
    • /
    • pp.732-736
    • /
    • 2016
  • Air conditioning part designs are moving towards higher efficiency and productivity. The expansion device is one of the core parts of an air conditioning system and controls the refrigerant quantity, evaporation load, compression capacity, and condensation capacity. In this study, an electronic expansion valve for two working fluids ($CO_2$ and R134a) was developed for air conditioning systems in vehicles. The valve uses an eccentric cam driving structure instead of a lead screw to decrease manufacturing costs and increase productivity. The pressure resistance and flow rate performance was evaluated using numerical analysis. At maximum operation conditions and burst pressure conditions with $CO_2$, the maximum stresses on the valve model were about 98 MPa and 223 MPa, respectively. The maximum flow rates of $CO_2$ and R134a with different orifice openings were about 550 kg/h and 386 kg/h, respectively. The performance with R134a was verified by experiments.

Performance of R430A on Refrigeration System of Domestic Water Purifiers (대체냉매 R430A를 적용한 정수기 냉동시스템의 성능 평가)

  • Park, Ki-Jung;Lee, Yo-Han;Jung, Dong-Soo;Kim, Kyoung-Kee
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
    • /
    • v.21 no.2
    • /
    • pp.109-117
    • /
    • 2009
  • In this study, thermodynamic performance of R430A is examined both numerically and experimentally in an effort to replace HFC134a used in the refrigeration system of domestic water purifiers. Even though HFC134a is used predominantly in such a system these days, it needs to be phased out in the near future in Europe and most of the developed countries due to its high global warming potential. To solve this problem, cycle simulation and experimental measurements are carried out with a new refrigerant mixture of 76%R152a124% R600a using actual domestic water purifiers. This mixture is numbered and listed as R430A by ASHRAE recently. Test results show that the system performance with R430A is greatly influenced by the amount of charge due to the small internal volume of the refrigeration system of the domestic water purifiers. With the optimum amount of charge of 21 to 22 grams, about 50% of HFC134a, the energy consumption of R430A is 13.4% lower than that of HFC 134a. The compressor dome and discharge temperatures and condenser center temperature of R430A are very similar to those of HFC134a at the optimum charge. Overall, R430A, a new long term environmentally safe refrigerant, is a good alternative for HFC134a requiring little change in the refrigeration system of the domestic water purifiers.