Summary
In the air-conditioning and refrigeration industry, the efforts to protect the environment have mainly focused on carbon dioxide as an alternative refrigerant. Several devices have been proposed and studied to improve the steady-state performance of CO2 heat pump system, such as an expander, two-stage compressor and internal heat exchanger. To enhance the heat transfer characteristics, micro-fin tubes are widely used and its enhancement was quantitatively investigated in this study. The effects of the tube orientation of horizontal, vertical, and inclined arrangements are also studied. As a result, the internal heat exchanger increased COP by 7.1-9.1%, the two-stage gas injection cycle increased COP by 16.5%. Average evaporation heat transfer coefficients for micro-fin tubes were approximately 150-210% in horizontal tube, 110-210% in vertical tube, and 110-170% in inclined tube higher than those for the smooth tube.
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Details
- Original title: Studies on the performance and heat transfer of a CO2 heat pump system.
- Record ID : 2010-0931
- Languages: English
- Source: ACRA-2009. The proceedings of the 4th Asian conference on refrigeration and air conditioning: May 20-22, 2009, Taipei, R.O.C.
- Publication date: 2009/05/20
Links
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Indexing
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Themes:
Heat pumps techniques;
CO2 - Keywords: Geometry; Enhancement; Microfin tube; Liquid-vapour exchanger; Heat transfer; Bare pipe; Two-stage system; Compression system; Heat pump; Expander; Survey; COP; Refrigerant; Heat exchanger; CO2
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- Date : 2007/08/21
- Languages : English
- Source: ICR 2007. Refrigeration Creates the Future. Proceedings of the 22nd IIR International Congress of Refrigeration.
- Formats : PDF
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Thermal-to-work and thermal-to-thermal recovery...
- Author(s) : STAICOVICI M. D. N.
- Date : 2012/06/25
- Languages : English
- Source: 10th IIR-Gustav Lorentzen Conference on Natural Working Fluids (GL2012). Proceedings. Delft, The Netherlands, June 25-27, 2012.
- Formats : PDF
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Heat transfer characteristics of CO2 in spirall...
- Author(s) : KOYAMA S., KUWAHARA K.
- Date : 2009/05/20
- Languages : English
- Source: ACRA-2009. The proceedings of the 4th Asian conference on refrigeration and air conditioning: May 20-22, 2009, Taipei, R.O.C.
- Formats : PDF
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- Author(s) : YARI M., SIROUSAZAR M.
- Date : 2008
- Languages : English
- Source: Int. J. Energy Res. - vol. 32 - n. 7
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- Date : 2015/03
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- Source: International Journal of Refrigeration - Revue Internationale du Froid - vol. 51
- Formats : PDF
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