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 Study of the Effects of Refrigerant Fraction on Auto-Cascade Refrigeration System of Evaporation Temperature

2014 ◽  
Vol 889-890 ◽  
pp. 321-324
Author(s):  
Da Yu Zheng ◽  
Dan Li ◽  
Jia Zheng ◽  
Li Ping Gao ◽  
Yi Ming Zhang
Keyword(s):  
Experimental Study ◽  
Low Temperature ◽  
Refrigeration Cycle ◽  
Refrigeration System ◽  
Evaporation Temperature ◽  
Cycle System ◽  
Cascade Refrigeration System ◽  
Cascade Refrigeration ◽  
Relationship Of ◽  
Working Efficiency

Non-azeotropic auto-cascade refrigeration system utilizes various components of different boiling refrigerant to get low-temperature. With R22, R23 and R14 as a non-azeotropic refrigerant auto-cascade refrigeration cycle system. Through the experimental study of non-azeotropic refrigerant charging and the ratio between the amount of charge, to analyze the effect of these three refrigerants charging and relationship of the fraction on the whole refrigeration cycle refrigeration temperature. To improve overall non-azeotropic auto-cascade refrigeration systems working efficiency. So as to achieve the purpose of energy saving.

A novel low-temperature absorption–compression cascade refrigeration system

2015 ◽  
Vol 75 ◽  
pp. 504-512 ◽  
Author(s):  
Yingjie Xu ◽  
FuSheng Chen ◽  
Qin Wang ◽  
Xiaohong Han ◽  
Dahong Li ◽  
...  
Keyword(s):  
Low Temperature ◽  
Refrigeration System ◽  
Cascade Refrigeration System ◽  
Cascade Refrigeration

Energy and Exergy Analysis of Cascade Refrigeration System Using MC22 and MC134 on HTC, R404A and R502 on LTC

2021 ◽  
Vol 80 (1) ◽  
pp. 73-83
Author(s):  
Hendri ◽  
Roswati Nurhasanah ◽  
Prayudi ◽  
Suhengki
Keyword(s):  
Low Temperature ◽  
Exergy Analysis ◽  
Refrigeration System ◽  
Low Temperature Storage ◽  
Energy And Exergy ◽  
Energy And Exergy Analysis ◽  
Cascade Refrigeration System ◽  
Cascade Refrigeration ◽  
Better Than ◽  
Temperature Storage

Low temperature storage with a single refrigeration system only stable up to 228 K temperature. The purpose of this study is to develop a low temperature cool storage with cascade refrigeration system, with hydrocarbon refrigerants in terms of energy and exergy analysis. Experimental research in laboratories using refrigerant hydrocarbon MC22 and MC134 on the hight temperature circuit, and R404A and R502 using on low temperature circuit. Condenser heat exchanger using a type of exchanger plate. Resulting from this research, obtained that result the MC22/R404A, MC22/R502 and MC134/R404A refrigerant pair can reach a temperature of 220 K. The MC22/R404A refrigerant pair has god performance, COP, total loss exergy, and exergy efficiency is better than MC22/R502, and MC134/R04A refrigerant pairs.

A Totally Heat-Driven Refrigeration System Using Low-Temperature Heat Sources for Low-Temperature Applications

2019 ◽  
Vol 27 (02) ◽  
pp. 1950012 ◽  
Author(s):  
Zeynab Seyfouri ◽  
Mehran Ameri ◽  
Mozaffar Ali Mehrabian
Keyword(s):  
Low Temperature ◽  
Heat Source ◽  
Rankine Cycle ◽  
Exergy Efficiency ◽  
Working Fluid ◽  
Refrigeration Cycle ◽  
Water Mixture ◽  
Refrigeration System ◽  
Power Requirement ◽  
Temperature Heat

In the present study, a totally heat-driven refrigeration system is proposed and thermodynamically analyzed. This system uses a low-temperature heat source such as geothermal energy or solar energy to produce cooling at freezing temperatures. The proposed system comprises a Rankine cycle (RC) and a hybrid GAX (HGAX) refrigeration cycle, in which the RC provides the power requirement of the HGAX cycle. An ammonia–water mixture is used in both RC and HGAX cycles as the working fluid. A comparative study is conducted in which the proposed system is compared with two other systems using GAX cycle and/or a single stage cycle, as the refrigeration cycle. The study shows that the proposed system is preferred to produce cooling at temperatures from 2∘C to [Formula: see text]C. A detailed parametric analysis of the proposed system is carried out. The results of the analysis show that the system can produce cooling at [Formula: see text]C using a low-temperature heat source at 133.5∘C with the exergy efficiency of about 20% without any input power. By increasing the heat source temperature to 160∘C, an exergy efficiency of 25% can be achieved.

scholarly journals The influence of traffic and wood combustion on the stable isotopic composition of carbon monoxide

2008 ◽  
Vol 8 (6) ◽  
pp. 19561-19604
Author(s):  
M. Saurer ◽  
A. S. H. Prévôt ◽  
J. Dommen ◽  
J. Sandradewi ◽  
U. Baltensperger ◽  
...  
Keyword(s):  
Carbon Monoxide ◽  
Isotopic Composition ◽  
Mass Balance ◽  
Balance Equation ◽  
Isotope Ratio ◽  
Rural Site ◽  
Mass Balance Equation ◽  
Wood Combustion ◽  
Isotope Mass Balance ◽  
The Village

Abstract. Carbon monoxide in the atmosphere is originating from various combustion and oxidation processes. Recently, the proportion of CO resulting from the combustion of wood for domestic heating may have increased due to political measures promoting this renewable energy source. Here, we used the stable isotope composition of CO (δ13C and δ18O) for the characterization of different CO sources in Switzerland, along with other indicators for traffic and wood combustion (NOx-concentration, aerosol light absorption at different wavelengths). We assessed diurnal variations of the isotopic composition of CO at 3 sites during winter: a village site dominated by domestic heating, a site close to a motorway and a rural site. The isotope ratios of wood combustion emissions were studied at a test facility, indicating significantly lower δ18O of CO from wood combustion compared to traffic emissions. At the village and the motorway site, we observed very pronounced diurnal δ18O-variations of CO with an amplitude of up to 8‰. Solving the isotope mass balance equation for three distinct sources (wood combustion, traffic, clean background air) resulted in diurnal patterns consistent with other indicators for wood burning and traffic. The average night-time contribution of wood-burning to total CO was 70% at the village site, 47% at the motorway site and 28% at the rural site based on the isotope mass balance. As this analysis showed a strong sensitivity towards the pure source isotope values, we additionally applied a combined CO/NOx-isotope model for verification. Here, we separated the CO emissions into different sources based on different CO/NOx emissions ratios for wood combustion and traffic, and inserted this information in the isotope mass balance equation. Accordingly, a highly significant agreement between measured and calculated δ18O-values of CO was found (r=0.67, p<0.001). While different proxies for wood combustion all have their uncertainties, our results indicate that the oxygen isotope ratio of CO (but not the carbon isotope ratio) is an independent sensitive tool for source attribution studies.

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