Thermodynamic Analysis of a R32/CO2 Cascade Refrigeration Cycle

2013 ◽  
Vol 732-733 ◽  
pp. 527-530 ◽  
Author(s):  
Jian Xiao ◽  
Ying Fu Liu
Keyword(s):  
Low Temperature ◽  
Thermodynamic Analysis ◽  
Working Conditions ◽  
Temperature Difference ◽  
Refrigeration Cycle ◽  
Cascade Refrigeration

A R32/CO2 cascade refrigeration cycle was analyzed thermodynamically, the results show that: Under given working conditions, there exists the best condensing temperature of the low-temperature circuit to make the maximum COP of the cycle. The lower evaporating temperature is, the lower the best condensing temperature of the low-temperature circuit is. Under the same evaporating temperature, COP increases and mH/mL decreases along with condensing temperature decreasing, under the same condensing temperature, COP decreases and mH/mL increases along with condensing temperature decreasing. To reduce the temperature difference in the cascade-condenser can increase COP and decrease mH/mL.

Thermodynamic analysis of auto-cascade refrigeration cycles, with and without ejector, for ultra low temperature freezing using a mixture of refrigerants R600a and R1150

2021 ◽  
pp. 117598
Author(s):  
Enrique Ángel Rodríguez-Jara ◽  
Francisco José Sánchez-de-la-Flor ◽  
José Antonio Expósito-Carrillo ◽  
José Manuel Salmerón-Lissén
Keyword(s):  
Low Temperature ◽  
Thermodynamic Analysis ◽  
Cascade Refrigeration

Thermodynamic Analysis of a Cascade Refrigeration Cycle for Venus Lander Electronics Cooling

2019 ◽  
Vol 33 (3) ◽  
pp. 762-772
Author(s):  
Kevin R. Anderson ◽  
Thomas J. Gross ◽  
Christopher McNamara ◽  
Ariel Gatti
Keyword(s):  
Thermodynamic Analysis ◽  
Electronics Cooling ◽  
Refrigeration Cycle ◽  
Cascade Refrigeration

scholarly journals Advanced Thermodynamic Analysis of a Transcritical R744 Booster Refrigerating Unit with Dedicated Mechanical Subcooling

Energies ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 3058 ◽  
Author(s):  
Paride Gullo
Keyword(s):  
Low Temperature ◽  
Thermodynamic Analysis ◽  
Temperature Difference ◽  
Exergy Analysis ◽  
Refrigeration System ◽  
Outdoor Temperature ◽  
Medium Temperature ◽  
High Stage ◽  
Thermodynamic Performance ◽  
Priority Needs

In this work the thermodynamic performance of a transcritical R744 booster supermarket refrigeration system equipped with R290 dedicated mechanical subcooling (DMS) was exhaustively investigated with the aid of the advanced exergy analysis. The outcomes obtained suggested that improvement priority needs to be addressed to the manufacturing of more efficient high-stage (HS) compressors, followed by the enhancement of the gas cooler/condenser (GC), of the medium-temperature (MT) evaporators, of the R290 compressor, and of the low-temperature (LT) evaporators. These conclusions were different from those drawn by the application of the conventional exergy assessment. Additionally, it was found that GC can be enhanced mainly by reducing the irreversibilities owing to the simultaneous interaction among the components. The R290 compressor would also have significantly benefitted from the adoption of such measures, as half of its avoidable irreversibilities were exogenous. Unlike the aforementioned components, all the evaporators were improvable uniquely by decreasing their temperature difference. Finally, the approach temperature of GC and the outdoor temperature were found to have a noteworthy impact on the avoidable irreversibilities of the investigated solution.

Entropy Analysis of a R32/CO2 Cascade Refrigeration Cycle

2014 ◽  
Vol 672-674 ◽  
pp. 1676-1679
Author(s):  
Jian Xiao ◽  
Ying Fu Liu
Keyword(s):  
Entropy Generation ◽  
Temperature Difference ◽  
Design Parameters ◽  
Refrigeration Cycle ◽  
Total Entropy ◽  
Entropy Analysis ◽  
Minimization Method ◽  
Entropy Generation Minimization ◽  
Cascade Refrigeration

In order to study the performance of a R32/CO2 cascade refrigeration cycle, entropy generation minimization method was adopted to get the influence of some important operating and design parameters on the performance of the system and entropy generations of each component and the whole system, such as the evaporating temperature(Te), the condensing temperature(Tk) and the temperature difference in the cascade condenser(ΔT). The results indicate that there are a maximum COP and a minimum total entropy generation of the system at the optimal condensing temperature of the cascade condenser when Te, Tk and ΔT are constant. The total entropy generations of the throttling device, the condenser and the compressor of HTC, the cascade condenser and the compressor of LTC are above 80% of the total entropy generation of the whole system.

Study on Energy Efficiency of a Low Temperature Refrigeration System

2011 ◽  
Vol 71-78 ◽  
pp. 292-295
Author(s):  
Lin Wang ◽  
Xiao Long Cui ◽  
Ying Ying Tan ◽  
Yu Wang
Keyword(s):  
Low Temperature ◽  
Mass Balance ◽  
Balance Equation ◽  
Total Mass ◽  
Cycle Performance ◽  
Refrigeration Cycle ◽  
Refrigeration System ◽  
Mass Balance Equation ◽  
Cascade Refrigeration ◽  
Low Temperature Refrigeration

Based on conservation of mass, total mass balance equation and component mass balance equation, mathematical models of thermodynamic for the auto cascade refrigeration cycle are established. Thermophysical properties in solving the governing equation are called from the NIST REFPROP7.0. Thermodynamic properties of the auto cascade refrigeration cycle using binary mixtures, namely, R170/R290, R23/R227ea, R116/R134a, R23/R134a, R170/R600a, R170/R600 and R170/R152a as refrigerants is evaluated. R170/R600a is selected for the low temperature refrigeration system, and the influences of cycle mole fraction, compression ratio and evaporating pressure on the cycle performance are analysed.

The Entropy Analysis on NH3/CO2 Cascade Refrigeration Cycle

2010 ◽  
Author(s):  
Yingbai Xie ◽  
Kuikui Cui ◽  
Luxiang Zong ◽  
Zhichao Wang
Keyword(s):  
Low Temperature ◽  
Entropy Production ◽  
Intermediate Temperature ◽  
Refrigeration Cycle ◽  
Total Entropy ◽  
Entropy Analysis ◽  
Minimization Method ◽  
Good Future ◽  
Cascade Refrigeration ◽  
Total Entropy Production

This paper introduces a cascade refrigeration cycle that uses natural refrigerants of CO2 and NH3 at low temperature. It introduces the character of CO2 and NH3, besides analyzes the cascade refrigeration cycle. The optimal intermediate temperature of NH3/CO2 cascade refrigeration cycle is determined by the entropy production minimization method. We analyze the four processes entropy production in both CO2 cycle (LT side) and NH3 cycle (HT side) and research how the total entropy production changes in the conditions of different T0, different TCL and different ΔT. We also find that in order to enhance the efficiency of NH3/CO2 cascade refrigeration cycle, it is necessary to reduce ΔT. It can be concluded that NH3/CO2 cascade refrigeration cycle has a good future.

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