• Title/Summary/Keyword: 냉매502

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Theoretical and Experimental Evaluation of R502 Alternatives in Low Temperature Applications (저온용 R502 대체 냉매의 이론 및 실험적 평가)

  • Kwon, S.L.;Park, Y.B.;Jung, D.S.;Kim, C.B.;Kang, D.J.
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.7 no.4
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    • pp.654-666
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    • 1995
  • R502 has been extensively used as a working fluid in transport refrigerating vehicles and low temperature refrigerating machines but is to be phased out by the end of 1995 due to ozone layer depletion problem. In this study, both theoretical cycle analysis and experiments were carried out to examine the best substitutes for R502. Theoretical results indicate that the alternatives available in the market today may replace R502 without significant changes in the system without suction line heat exchanger(SLHX). When the system contains a SLHX, however, COPs of the alternatives increase up to approximately 15~20% than those without the SLHX. But simultaneously, the discharge temperatures of the compressor also increrease significantly with the SLHX. Actual test results obtained from the experiment with a transport vehicle's refrigerator indicate the similar trend as those of the theoretical results. Especially, HFCs and their mixtures show lower discharge temperature than those of R502, which is one of the desirable features. Further research is needed to study the effect of the SLHX on the performance of the real machine as well as on the oil return for reliability of the system.

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Experimental study on the performance of R-502 alternative refrigerant mixtures (R-502 대체 혼합냉매의 성능에 관한 실험적 연구)

  • Park, D.M.;Jeoung, D.S.;Kim, J.B.;Kang, D.J.
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.9 no.2
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    • pp.198-209
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    • 1997
  • This paper is concerned about the performance of alternative refrigerants of R-502 which has been widely used in transport and low temperature refrigeration. A breadboard heat pump was constructed with counterflow heat exchangers and tested with R-502 and transitional alternatives of R-402A and R-402B and long-term alternatives of R-404A and R-507 to compare the performance of each refrigerant. Measurements were conducted at two different condensing temperatures of $43.3^{\circ}C$ and $52.0^{\circ}C$ and the evaporating temperature was varied over a range from $-25^{\circ}C$ to $-5^{\circ}C$. The evaporator superheat and condenser subcooling were maintained constant at about $5^{\circ}C$ for all tests. Test results showed that all alternative fluids tested in this research work can be used as 'drop-in' fluids to replace R-502 without any major problem. It is also found that in the long run HFC alternatives are to be used due to their favorable environmental characteristics and better performance.

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Performance of R502 Alternative Refrigerants for Low Temperature Applications (저온용 R502 대체냉매의 성능 평가)

  • Ha Jong-Chul;Hwang Ji-Hwan;Baek In-Chul;Jung Dongsoo
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.17 no.10
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    • pp.883-890
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    • 2005
  • In this study, 2 pure hydrocarbon refrigerants of R1270 (Propylene) and R290 (Propane) and 3 binary mixtures composed of R1270, R29O and R152a were tested in a refrigerating bench tester with a scroll compressor in an attempt to substitute R502 used in most of the low temperature applications. The test bench provided 3\sim3.5$ kW capacity and water and water/glycol mixture were employed as the secondary heat transfer fluids. All tests were conducted under the same external conditions resulting in the average saturation temperatures of -28 and $45^{\circ}C$ in the evaporator and condenser, respectively. Test results showed that all refrigerants tested had $9.6\sim18.7\%$ higher capacity and $17.1\sim27.3\%$ higher COP than R502. The compressor discharge temperature of R1270 was similar to that of R502 while those of all other refrigerants were $23.7\sim27.9\%$ lower than that of R502. For all alternative refrigerants, the amount of charge was reduced up to $60\%$ as compared to R502. Overall, these alternative refrigerants offer better system performance and reliability than R502 and can be used as long term substitutes for R502 due to their excellent environmental properties.

Performance Characteristics Study on an Alternative Refrigerant in Low Temperature Applications (저온용 대체냉매의 성능 특성 연구)

  • SHIN, JEONG-SUB;KIM, MAN-HOE
    • Transactions of the Korean hydrogen and new energy society
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    • v.27 no.4
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    • pp.462-469
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    • 2016
  • This paper presents the results of thermodynamic cycle analysis and performance tests of alternative mixtures in low temperature applications. Two near-azeotropic binary mixtures R-152a/R-1270 (35:65 by wt.%) and R-290/E170 (35:65 by wt.%) are considered in this study. They have zero ODP (Ozone Depletion Potential) and much lower GWP (Global Warming Potential) than R-404A which is an alternative of R-502. Refrigeration cycle characteristics such as cooling capacity, coefficient of performance, suction and discharge pressures and temperatures are compared to those for the baseline refrigerants (R-502 and R-404A) cycles. The performance tests are conducted at the evaporation and condensation temperatures of $5^{\circ}C$ and $45^{\circ}C$, subcooling and superheating temperatures of $5^{\circ}C$, respectively. Performance comparisons between baseline and alternative refrigerants are conducted on the same cooling capacity. The system performance of newly proposed refrigerant mixtures show promising results.

Performance and heat transfer characteristics of refrigeration system using R-502 alternatives (R-502의 대체냉매를 사용한 냉동시스템의 성능 및 열전달 특성)

  • 박창대;김민수;노승탁
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.11 no.5
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    • pp.624-632
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    • 1999
  • In order to replace CFC-502 which has been widely used in transportation and low temperature refrigeration system, performance tests using HFC-407A, HFC-404A and HFC-507 have been carried out. Measurements were conducted at two different condensing temperatures of $43.3^{\circ}C$and $54.5^{\circ}C$ for each refrigerant. System performance characteristics and heat transfer characteristics of each refrigerant were obtained at several compressor speeds and evaporating temperatures ranging from$-25^{\circ}C$ to $-10^{\circ}C$ Test results show that the use of tested alternative refrigerants without changing system components offers the potential performance improvement of a refrigeration system.

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A Study for Evaporation Heat Transfer Characteristic of R22/Rl14 Refrigerant Mixtures in a Horizontal Tube (수평증발관내 R22/R114 혼합냉매의 열전달 특성에 관한 연구)

  • 윤치한;이종인;하옥남
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.12 no.5
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    • pp.502-510
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    • 2000
  • Evaporation heat transfer characteristics were studied in a horizontal tube using R22/R114 non-azotropic refrigerant mixture. the heat transfer coefficient was high in the upper part for pure refrigerants, and heat transfer coefficient was low in the lower part for refrigerant mixtures. In the low quality region where nucleate boiling was dominant, the average heat transfer coefficient was low. In the region where forced convection was dominant, heat transfer coefficient was high. Results show that the heat transfer coefficient for pure refrigerants obtained by experiments were lower than those of Yoshida et al. but agreed well with Jung et al., and Chen et al. data. But the heat transfer coefficients for refrigerant mixtures were lower about 20% than those predicted by the equation for pure refrigerant.

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Heat and Mass Transfer Characteristics and Performance Evaluation of a Double-Tube Condenser for an Alternative Refrigerant (대체냉매의 2중관 응축기 열 및 물질전달과 성능평가)

  • 이상무;박병덕;소산번
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.14 no.6
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    • pp.468-476
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    • 2002
  • This paper deals with heat and mass transfer characteristics and performance evaluation of a counter flow double-tube condenser for a multi-component refrigerant mixture. The local heat and mass transfer characteristics of ternary zeotropic refrigerant mixtures composed of HFC32/HFC125/HFC134a are evaluated for a counter flow double-tube condenser cooled by water. Then, the local values of vapor quality, thermodynamic states at bulk vapor, vapor-liquid interface and bulk liquid, heat flux and condensation mass flux are obtained. The heat exchange performance for ternary zeotropic refrigerant mixtures composed of HFC32/HFC125/HFC134a on the total pressure drop and the heat transfer characteristics are also compared with those for R404A, R410A, R502, R22, R32, Rl23 and R134a.

A Study on the Performance Characteristics of the Soft Ice Cream Machine Run by Refrigerant Mixture (R-290/R-32) (혼합냉매(R-290/R-32)를 사용하는 소프트 아이스크림 제조기의 성능 특성에 관한 연구)

  • Kim, Nea-Hyun
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.18 no.2
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    • pp.719-725
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    • 2017
  • Frozen milk products are commonly made in small refrigeration machines. R-502 has long been used as a refrigerant for soft ice cream machines, but it is being replaced with R-404A due to the issue of ozone layer depletion. However, R-404A has high global warming potential, so it also needs to be replaced. In this study, a mixture of R-290 and R-32 was considered as a new refrigerant. An optimization and performance evaluation of the mixture were conducted for a freezer volume of 2.8 liters. The focus of the optimization was the appropriate refrigerant charge and the opening of the expansion valve. At the optimized conditions, ice cream was produced in 6 minutes and 24 seconds with the mixture, and the COP was 0.83. For R-404A, the ice cream production time was 6 minutes and 22 seconds, and the COP was 0.90. The results may be used for the design of food refrigeration machines and to optimize other refrigeration cycles.

Optimization of the Refrigerant Charge and the Expansion Valve Opening for the Soft Ice Cream Machine Using R-404A (R-404A를 사용하는 소프트 아이스크림 제조기의 냉매 충전량 및 팽창 밸브 개도 최적화)

  • Kim, Nae-Hyun
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.17 no.8
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    • pp.728-734
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    • 2016
  • The improvements of living and lifestyle have led to the increased sales of frozen milk products, such as soft ice cream or slush. These frozen milk products are commonly made in small refrigeration machines. R-502, which has long been used as the refrigerant in soft ice cream machines, is being replaced with R-404A due to the ozone layer depletion issue. In this study, an optimization and performance evaluation were conducted on a soft ice cream machine with a freezer volume of 2.8 liters. The optimization focused on the appropriate refrigerant charge and expansion valve opening. Under the optimized conditions, ice cream was produced in 10 minutes and 5 seconds, and the COP was 0.57. The performance tests included ice cream sales with no interval, ice cream sales with 30 second intervals and under extreme outdoor conditions. The results showed that 20 sales were possible with no interval, and infinite sales could be made with 30 seconds intervals. Ice cream sales were also possible under summer or winter outdoor conditions. The present results may be used for the design of food refrigeration machines as well as to optimize other refrigeration cycles.

Development of Computer Program for Computation of 12 Refrigerant Properties (12가지 냉매 (R11, R12, R13, R14, R21, R22, R23, R113, R114, R500, R502, C318)의 상태치계산 프로그램)

  • Lee Ki Bang;Chung M. K.
    • The Magazine of the Society of Air-Conditioning and Refrigerating Engineers of Korea
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    • v.16 no.5
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    • pp.477-483
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    • 1987
  • A FORTRAN code has been developed to calculate thermodynamic properties of 12 kinds of refrigerants. Input variables are temperature and pressure or temperature only depending on the saturation. The program output properties are specific volume, saturation pressure, enthalpy, entropy, specific heats and speed of sound. Sample calculations show that output properties are in very good agreements with thermodynamic tables and charts.

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