• Title/Summary/Keyword: Cascade Refrigeration System

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Prediction on Performance of Cascade Refrigeration System using Alternative Freon Refrigerants (대체 프레온계 냉매를 이용하는 이원 냉동시스템의 성능예측)

  • Roh, Geonsang
    • Journal of the Korean Society of Mechanical Technology
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    • v.13 no.1
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    • pp.73-79
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    • 2011
  • In this paper, cycle performance analysis of cascade refrigeration system using alternative FREON refrigerants are presented to offer the basic design data for the operating parameters of the system. The operating parameters considered in this study include subcooled and superheated degree, and evaporating and condensing temperature, temperature difference of cascade heat exchanger in cascade refrigeration system. The COP of cascade refrigeration system increases with the increasing subcooled degree, but there is no significant changes with the increasing superheated degree. The COP of cascade refrigeration system depends on evaporating and condensing temperatures of cascade heat exchanger. Therefore, subcooled degree, evaporating and condensing temperature of cascade heat exchanger using alternative FREON refrigerants have an effect on the COP of this system. In this paper, COP of cascade refrigeration system using R23 for low temperature system and R507A for high temperature system is higher 8 ~ 29 % than using R13 for low temperature system and R22 for high temperature system.

Prediction on Performance of Cascade Refrigeration System using Alternative Freon and Natural Refrigerants (대체 프레온 및 자연 냉매를 이용하는 이원 냉동시스템의 성능 예측)

  • Kim, Jong-Ryeol;Roh, Geon-Sang
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.13 no.4
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    • pp.1427-1433
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    • 2012
  • In this paper, cycle performance analysis of cascade refrigeration system using alternative FREON refrigerants and natural refrigerants are presented to offer the basic design data for the operating parameters of the system. The operating parameters considered in this study include subcooled and superheated degree, and condensing and evaporating temperature, temperature difference of cascade heat exchanger in cascade refrigeration system. The COP of cascade refrigeration system increases with the increasing subcooled degree, but there is no significant changes with the increasing superheated degree. The COP of cascade refrigeration system depends on evaporating and condensing temperatures of cascade heat exchanger. Therefore, subcooled degree, evaporating and condensing temperature of cascade heat exchanger using alternative FREON refrigerants and natural refrigerants have an effect on the COP of this system. In this paper, COP of cascade refrigeration system using (R23 / R290), (R23 / R600), (R23 / R600a), (R23 / R717), (R744 / R404A) are higher 20 ~ 36 % than (R23 / R22), using R23 for low temperature system and R22 for high temperature system.

Performance analysis of a R744 and R404A cascade refrigeration system with internal heat exchanger (내부 열교환기 부착 R744-R404A용 캐스케이드 냉동시스템의 성능 분석)

  • Oh, H.K.;Son, C.H.
    • Journal of Power System Engineering
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    • v.16 no.1
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    • pp.38-43
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    • 2012
  • This paper describes an analysis on performance of R744-R404A cascade refrigeration system with internal heat exchanger to optimize the design for the operating parameters of the system. The operating parameters considered in this study include subcooling and superheating degree, internal heat exchanger and compression efficiency, evaporating and condensing temperature in the R744 low- and R404A high-temperature cycle and temperature difference of cascade heat exchanger. The main results are summarized as follows : COP of cascade refrigeration system increases with the increasing of compression efficiency, but decreases with the increasing temperature difference of cascade heat exchanger. Also, the COP increases with the increasing of internal heat exchanger efficiency in high-temperature cycle, but decreases with that in low-temperature cycle. Therefore, internal heat exchanger efficiency, compressor efficiency and temperature difference of cascade heat exchanger on R744-R404A cascade refrigeration system have an effect on the COP of this system.

Performance Simulation of a R744-R717 Cascade Refrigeration System According to Operating Conditions (R744-R717 캐스케이드 냉동시스템에서 운전조건 변화에 따른 성능 해석)

  • Ryu, Jiho;Cho, Honghyun
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.27 no.10
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    • pp.497-505
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    • 2015
  • The evaporating temperature range required for the low temperature freezing system is from $-50^{\circ}C$ to $-30^{\circ}C$. Since it is difficult to keep the required capacity in a cabinet, it is advantageous to design the system using a cascade refrigeration system. Use of carbon dioxide and ammonia would be advantageous since ammonia is an environment-friendly working fluid and has a high capacity for performance improvement. To investigate the performance characteristics of the R744-R717 cascade refrigeration system, a theoretical model was developed and performance was analyzed according to cascade heat exchanger operating temperature. The optimal cascade R744 condensing temperature was $-5^{\circ}C$, and maximum COP was 1.13 when the temperature difference of the cascade heat exchanger was $5^{\circ}C$. In addition, the total system COP increased by 1.17 when the cascade temperature gap was $3^{\circ}C$ at the middle temperature of $-7.5^{\circ}C$.

Performance Characteristics of a Cascade Refrigeration System with Internal Heat Exchanger using Carbon Dioxide (R744) and Propane (R290) (내부 열교환기 부착 $CO_2-C_3H_8$용 캐스케이드 냉동시스템의 성능 특성)

  • Son, Chang-Hyo
    • Journal of Hydrogen and New Energy
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    • v.20 no.6
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    • pp.526-533
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    • 2009
  • In this paper, cycle performance analysis of $CO_2-C_3H_8$ (R744-R290) cascade refrigeration system with internal heat exchanger is presented to offer the basic design data for the operating parameters of the system. The operating parameters considered in this study include subcooling and superheating degree and gas cooling pressure and evaporating temperature in the propane (R290) low temperature cycle and the carbon dioxide (R744) high temperature cycle. The main results were summarized as follows : The COP of cascade refrigeration system of $CO_2-C_3H_8$ (R744-R290) increases with the increasing subcooling degree, but decreases with the increasing superheating degree. The COP of cascade refrigeration system increases with the increasing evaporating temperature, but decreases with the increasing gas cooling pressure. Therefore, superheating and subcooling degree, compressor efficiency, evaporating temperature and gas cooling pressure of $CO_2-C_3H_8$ (R744-R290) cascade refrigeration system have an effect on the COP of this system.

The Characteristic of Propane(R290)-Ethane(R170) as Refrigerant in the Cascade Refrigeration System (캐스캐이드 냉동시스템에서 냉매로서의 프로판-에탄 냉매의 성능 분석)

  • Kim, P.H.;Lee, B.H.;Jeong, H.M.;Chung, H.S.;Kim, C.S.
    • Journal of Power System Engineering
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    • v.11 no.4
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    • pp.50-55
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    • 2007
  • Nowadays, demands on super low temperature condition for industrial and commercial uses are thriving. Considering of its wide application in the present and the future, study of the super-low temperature refrigeration system should be actively carried out. This study is aimed to investigate refrigeration capacity and coefficient of performance(COP) of the cascade refrigeration system, as well as to get the system which can reach evaporator temperature of $-70^{\circ}C$. For this purpose, R290 and R170 are charged in high stage and low stage respectively. Finally the characteristics of system using R290 and R170 will be proposed. Additionally, In this experiment, the flow rate of air flowing through the LS evaporator and the compressor inlet pressure were varied to investigate the refrigeration capacity and coefficient of performance characteristics.

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Performance Characteristics of Cascade Refrigeration System Using R744 and R410A (R744-R410A용 이원 냉동시스템 성능 특성)

  • Ku, Hak-Keun
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.14 no.4
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    • pp.1548-1554
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    • 2013
  • This paper presents the analysis on performance characteristics of R744-R410A cascade refrigeration system to offer the basic design data for the operating parameters of this system. The performance of cascade refrigeration system is analyzed by using EES program. The operating parameters include compressor efficiency, and condensing and evaporating temperature in R410A high- and R744 low-temperature cycle, respectively. The COP of this system increases with the decrease of condensing temperature, and increases with the increasing evaporating temperature. And the COP of this system increases with the compression efficiency. Therefore, it can be seen that the compression efficiency, and evaporating and condensing temperature of R744-R410A cascade refrigeration system have an effect on the COP of this system. Also, it can be known that the cascade evaporation temperature with the highest efficiency in each parameter is present. Thus, it is an important to design R744-R410A cascade refrigeration system by considering these parameters.

Performance Analysis of an Ammonia(R717) and Carbon Dioxide(R744) Two-Stage Cascade Refrigeration System ($NH_3-CO_2$를 사용하는 이원 냉동 시스템의 성능 분석)

  • Son, Chang-Hyo
    • Journal of the Korean Institute of Gas
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    • v.14 no.1
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    • pp.1-7
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    • 2010
  • In this paper, cycle performance analysis of $NH_3-CO_2$(R717-R744) two-stage cascade refrigeration system is presented to offer the basic design data for the operating parameters of the system. The operating parameters considered in this study include subcooling and superheating degree, compressor efficiency, and condensing and evaporating temperature in the ammonia(R717) high temperature cycle and the carbon dioxide low temperature cycle. The main results were summarized as follows : The COP of two-stage cascade refrigeration system increases with the increasing subcooling degree, but decreases with the increasing superheating degree. The COP of two-stage cascade refrigeration system decreases with the increasing condensing temperature, but increases with the increasing evaporating temperature. And the COP of two-stage cascade refrigeration system increases with increasing the compressor efficiency. Therefore, superheating and subcoolng degree, compressor efficiency, and evaporating and condensing temperature of $NH_3-CO_2$(R717-R744) two-stage cascade refrigeration system have an effect on the COP of this system.

Prediction on Maximum Performance of Cascade Refrigeration System Using R717 and R744 (R718-R744용 캐스케이드 냉동시스템의 최대 성능 예측)

  • Roh, Geun-Sang;Son, Chang-Hyo
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.10 no.10
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    • pp.2565-2571
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    • 2009
  • In this paper, cycle performance analysis of cascade refrigeration system using $NH_3-CO_2$(R717-R744) is presented to offer the basic design data for the operating parameters of the system. The operating parameters considered in this study include subcooling and superheating degree and condensing and evaporating temperature in the ammonia(R717) high temperature cycle and the carbon dioxide low temperature cycle. The COP of cascade refrigeration system increases with the increasing superheating degree, but decreases with the increasing subcooling degree. The COP of cascade refrigeration system increases with the increasing condensing temperature, but decreases with the increasing evaporating temperature. Therefore, superheating and subcoolng degree, evaporating and condensing temperature of cascade refrigeration system using $NH_3-CO_2$ have an effect on the COP of this system. A multilinear regression analysis was employed in terms of subcooling, superheating, evaporating, condensing, and cascade heat exchanger temperature difference in order to develop mathematical expressions for maximum COP and an optimum evaporating temperature.

Performance of Carbon Dioxide System for Freezing and Refrigeration (이산화탄소를 이용한 냉동·냉장 시스템의 성능연구)

  • Kim, Yoonsup;Yun, Rin
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.27 no.2
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    • pp.81-86
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    • 2015
  • Performance of freezing and refrigeration systems in supermarket, which utilized $CO_2$ as a refrigerant, was investigated by using the Pack Calculation II. The configuration of simulated systems was basic parallel refrigeration system, cascade system, and two-stage system. The $CO_2$ cascade system showed higher COP than basic parallel R404A system by 13% for MT and 62% for LT, respectively. Among the $CO_2$ cascade systems, R717(MT)-$CO_2$(LT) showed the highest performance. Open-type intercooler method showed higher performance than liquid injection for the two-stage $CO_2$ systems.