scholarly journals Effect of an Internal Heat Exchanger on Performance of the Transcritical Carbon Dioxide Refrigeration Cycle with an Expander

Entropy ◽  
2014 ◽  
Vol 16 (11) ◽  
pp. 5919-5934 ◽  
Author(s):  
Zhenying Zhang ◽  
Lili Tian ◽  
Yanhua Chen ◽  
Lirui Tong
Keyword(s):  
Carbon Dioxide ◽  
Heat Exchanger ◽  
Internal Heat ◽  
Refrigeration Cycle ◽  
Internal Heat Exchanger ◽  
Transcritical Carbon Dioxide

Transcritical Carbon Dioxide Refrigeration as an Alternative to Subcritical Plants

2016 ◽  
pp. 100-159
Author(s):  
Adriana Greco ◽  
Ciro Aprea ◽  
Angelo Maiorino
Keyword(s):  
Carbon Dioxide ◽  
Heat Exchanger ◽  
Critical Temperature ◽  
Experimental Analysis ◽  
Internal Heat ◽  
Refrigeration Cycle ◽  
Desiccant Wheel ◽  
Internal Heat Exchanger ◽  
Transcritical Carbon Dioxide ◽  
Vapour Compression

Carbon dioxide (R744) is as a valid alternative to classical substances such as HFCs used in vapour compression plants. A transcritical refrigeration cycle is needed because the critical temperature of carbon dioxide is usually lower than the ambient temperature. In this chapter the performances of a transcritical cycle have been evaluated with a prototype R744 system working as a classical spit-systems to cool air. An experimental analysis has been carried out on the effect of: refrigerant charge, internal heat exchanger, heat rejection pressure on the energetic performances of the transcritical plant. An experimental analysis of a hybrid trans-critical refrigerator-desiccant wheel system has been carried out in order to improve the COP. The experimental transcritical cycle has been examined in comparison with a classical vapour compression plant working with the R134a.

Transcritical Carbon Dioxide Refrigeration as an Alternative to Subcritical Plants

2015 ◽  
pp. 295-359
Author(s):  
Adriana Greco ◽  
Ciro Aprea ◽  
Angelo Maiorino
Keyword(s):  
Carbon Dioxide ◽  
Heat Exchanger ◽  
Critical Temperature ◽  
Experimental Analysis ◽  
Internal Heat ◽  
Refrigeration Cycle ◽  
Desiccant Wheel ◽  
Internal Heat Exchanger ◽  
Transcritical Carbon Dioxide ◽  
Vapour Compression

Carbon dioxide (R744) is as a valid alternative to classical substances such as HFCs used in vapour compression plants. A transcritical refrigeration cycle is needed because the critical temperature of carbon dioxide is usually lower than the ambient temperature. In this chapter the performances of a transcritical cycle have been evaluated with a prototype R744 system working as a classical spit-systems to cool air. An experimental analysis has been carried out on the effect of: refrigerant charge, internal heat exchanger, heat rejection pressure on the energetic performances of the transcritical plant. An experimental analysis of a hybrid trans-critical refrigerator-desiccant wheel system has been carried out in order to improve the COP. The experimental transcritical cycle has been examined in comparison with a classical vapour compression plant working with the R134a.

scholarly journals Experimental evaluation of an internal heat exchanger in a CO2 subcritical refrigeration cycle with gas-cooler

2015 ◽  
Vol 80 ◽  
pp. 31-41 ◽  
Author(s):  
Rodrigo Llopis ◽  
Carlos Sanz-Kock ◽  
Ramón Cabello ◽  
Daniel Sánchez ◽  
Enrique Torrella
Keyword(s):  
Heat Exchanger ◽  
Experimental Evaluation ◽  
Internal Heat ◽  
Refrigeration Cycle ◽  
Internal Heat Exchanger

scholarly journals Energy, Exergy, and Environmental (3E) Analysis of Hydrocarbons as Low GWP Alternatives to R134a in Vapor Compression Refrigeration Configurations

2021 ◽  
Vol 11 (13) ◽  
pp. 6226
Author(s):  
Morteza Ghanbarpour ◽  
Adrián Mota-Babiloni ◽  
Bassam E. Badran ◽  
Rahmatollah Khodabandeh
Keyword(s):  
Heat Exchanger ◽  
Environmental Impact ◽  
Impact Analysis ◽  
Internal Heat ◽  
Refrigeration Cycle ◽  
Vapor Compression ◽  
Two Stage ◽  
Internal Heat Exchanger ◽  
Vapor Injection ◽  
Flash Tank

The phase-down of hydrofluorocarbons and substitution with low global warming potential values are consequences of the awareness about the environmental impacts of greenhouse gases. This theoretical study evaluated the energy and exergy performances and the environmental impact of three vapor compression system configurations operating with the hydrocarbons R290, R600a, and R1270 as alternatives to R134a. The refrigeration cycle configurations investigated in this study include a single-stage cycle, a cycle equipped with an internal heat exchanger, and a two-stage cycle with vapor injection. According to the results, the alternative hydrocarbon refrigerants could provide comparable system performance to R134a. The analysis results also revealed that using an internal heat exchanger or a flash tank vapor injection could improve the system’s efficiency while decreasing the heating capacity. The most efficient configuration was the two-stage refrigeration cycle with vapor injection, as revealed by the exergy analysis. The environmental impact analysis indicated that the utilization of environmentally-friendly refrigerants and improving the refrigeration system’s efficiency could mitigate equivalent CO2 emissions significantly. The utilization of hydrocarbons reduced the carbon footprint by 50%, while a 1% to 8% reduction could be achieved using the internal heat exchanger and flash tank vapor injection.

Effects of an Internal Heat Exchanger in a Refrigerant System with Carbon Dioxide on Its Cooling Coefficient of Performance and Cooling Capacity

2008 ◽  
Vol 34 (5) ◽  
pp. 505-512 ◽  
Author(s):  
Shogo Tamaki ◽  
Yuuko Fujii ◽  
Yohsuke Matsushita ◽  
Hideyuki Aoki ◽  
Takatoshi Miura ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Heat Exchanger ◽  
Internal Heat ◽  
Cooling Capacity ◽  
Coefficient Of Performance ◽  
Internal Heat Exchanger
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