Experimental evaluation of the internal heat exchanger influence on a vapour compression plant energy efficiency working with R22, R134a and R407C

Energy ◽  
2005 ◽  
Vol 30 (5) ◽  
pp. 621-636 ◽  
Author(s):  
J NAVARROESBRI ◽  
R CABELLO ◽  
E TORRELLA
Keyword(s):  
Energy Efficiency ◽  
Heat Exchanger ◽  
Experimental Evaluation ◽  
Internal Heat ◽  
Internal Heat Exchanger ◽  
Vapour Compression

THERMODYNAMIC ANALYSIS AND EXPERIMENTAL RESEARCH OF TRANSCRITICAL CO2 CYCLE WITH INTERNAL HEAT EXCHANGER AND DUAL EXPANSION

2013 ◽  
Vol 21 (01) ◽  
pp. 1350005 ◽  
Author(s):  
Z. WANG ◽  
Y. GONG ◽  
X. H. WU ◽  
W. H. ZHANG ◽  
Y. L. LU
Keyword(s):  
Heat Exchanger ◽  
Experimental Evaluation ◽  
Pressure Fluctuations ◽  
Internal Heat ◽  
Energy Performance ◽  
Evaporation Temperature ◽  
Internal Heat Exchanger ◽  
Side Pressure ◽  
Wide Range ◽  
Compressor Power

This work presents the experimental evaluation of the energy performance of transcritical CO2 refrigeration and heat pump systems. The optimal gas cooler pressures and the optimal COP have been analyzed from a thermodynamic point of view. The systems used a new dual expansion valve and a balance CO2 liquid receiver adjustment device, which can control high and low side pressure effectively. Moreover, we demonstrate the influence of the internal heat exchanger (IHX) on the systems' performances, on the basis of the analysis of the relative COP index RCOPI, the compressor power index RPCI and other parameters which can confirm the truth of. The experimental evaluation covers five evaporating levels (-10 to 10°C) and in a wide range of gas cooler pressures (75 to 120 bar). It is concluded that with the IHX system, compressor power is relatively low when the high side pressure is over 100 bar, and the evaporation temperature is below 0°C. The COP of the system without the IHX is slightly higher than the system with the IHX; it is increasing about 3% to 5%, when the evaporation temperature is over 5°C. Relative to the single expansion process, the dual expansion cycle can decrease the influence of pressure fluctuations of CO2 supercritical fluid and liquid mixture on the systems.

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

Performance characteristics of natural-refrigerants- based ejector expansion refrigeration cycles

2009 ◽  
Vol 223 (5) ◽  
pp. 543-550 ◽  
Author(s):  
J Sarkar
Keyword(s):  
Heat Exchanger ◽  
Internal Heat ◽  
Area Ratio ◽  
Operating Conditions ◽  
Coefficient Of Performance ◽  
Internal Heat Exchanger ◽  
Optimum Parameters ◽  
And Performance ◽  
Vapour Compression ◽  
Cycle Temperature

The thermodynamic analyses and comparison of three natural-refrigerants-based vapour compression refrigeration cycles (ammonia, isobutane, and propane) are presented in this article using a constant pressure mixing ejector as an expansion device. Optimization of the area ratio of the ejector is done based on maximum cooling coefficient of performance (COP) and performance improvement for different operating conditions. The effect of using an internal heat exchanger is studied as well. Results show that optimum area ratio and cooling COP increases with a decrease in cycle temperature lift, whereas the COP improvement over basic expansion cycle increases with the increase in cycle temperature lift. Study shows that the optimum parameters, as well as performance using the ejector as an expansion device, are strongly dependent on the refrigerant properties as well as the operating conditions. The optimum area ratio is maximum for ammonia and minimum for propane, whereas maximum cooling COPs are similar. Using the ejector as an expansion device, propane yields a maximum COP improvement of 26.1 per cent followed by isobutane (22.8 per cent) and ammonia (11.7 per cent) for studies ranges. The effect of using an internal heat exchanger in the ejector expansion refrigeration cycle is found to be not profitable.

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.

scholarly journals Drop-in analysis of an internal heat exchanger in a vapour compression system using R1234ze(E) and R450A as alternatives for R134a

Energy ◽  
2015 ◽  
Vol 90 ◽  
pp. 1636-1644 ◽  
Author(s):  
Adrián Mota-Babiloni ◽  
Joaquín Navarro-Esbrí ◽  
Ángel Barragán-Cervera ◽  
Francisco Molés ◽  
Bernardo Peris
Keyword(s):  
Heat Exchanger ◽  
Internal Heat ◽  
Compression System ◽  
Internal Heat Exchanger ◽  
Vapour Compression

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.

Experimental evaluation of the effect of an internal heat exchanger on a transcritical CO2 ejector system

2011 ◽  
Vol 12 (2) ◽  
pp. 146-153 ◽  
Author(s):  
Xiao-xiao Xu ◽  
Guang-ming Chen ◽  
Li-ming Tang ◽  
Zhi-jiang Zhu ◽  
Shuang Liu
Keyword(s):  
Heat Exchanger ◽  
Experimental Evaluation ◽  
Internal Heat ◽  
Internal Heat Exchanger ◽  
Ejector System
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