Summary
In this study, a tube-in-tube heat exchanger model applicable to supercritical CO2 and water was developed. The developed model is first validated with some existing measurements. Normally, the variation of the heat transfer rate for a constant-property working fluid shows a monotonic decrease from the inlet of minimum heat capacity flow rate (Cmin). By contrast, the CO2 may present a local minimum and a local maximum along the length of the heat exchanger, provided CO2 passes through the pseudo-critical temperature, and this phenomenon becomes more and more pronounced when the pressure is close to the critical pressure. In contrast, it is possible for a local maximum heat transfer rate to occur near the inlet of Cmin even when the CO2 does not pass through the pseudo-critical point. This happens when Cmin is on the water side and the property variation of CO2 is taken into account. The calculation also shows that the effect of the inlet pressure on the variation of the CO2 temperature is not as apparent as the effect of the inlet pressure on the heat transfer rate, even when there is a significant change in the overall heat transfer coefficient, implying that the heat transfer characteristics of CO2 near the pseudo-critical region is similar to normal refrigerants, which show an invariant temperature at the condensation point. Hence, it would be beneficial to extend the influence of the pseudo-critical region when taking the heat transfer augmentation into consideration.
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Details
- Original title: Performance of a tube-in-tube CO2 gas cooler.
- Record ID : 30005925
- Languages: English
- Source: International Journal of Refrigeration - Revue Internationale du Froid - vol. 35 - n. 7
- Publication date: 2012/11
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Indexing
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Themes:
Evaporators, condensers and other heat exchangers;
CO2 - Keywords: Supercritical state; Gas cooler; R744; Model; Heat exchanger; Water; CO2
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Multi-physics simulation of CO2 gas coolers usi...
- Author(s) : ROSSETTI A., MARINETTI S., MINETTO S.
- Date : 2018/06
- Languages : English
- Source: International Journal of Refrigeration - Revue Internationale du Froid - vol. 90
- Formats : PDF
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A generalized moving-boundary algorithm to pred...
- Author(s) : BAHMAN A. A., ZIVIANI D., GROLL E. A.
- Date : 2020/10
- Languages : English
- Source: International Journal of Refrigeration - Revue Internationale du Froid - vol. 118
- Formats : PDF
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Investigation of shape‐optimized, non‐round tub...
- Author(s) : TANCABEL J., AUTE V., LING J.
- Date : 2022/06/13
- Languages : English
- Source: 15th IIR-Gustav Lorentzen Conference on Natural Refrigerants (GL2022). Proceedings. Trondheim, Norway, June 13-15th 2022.
- Formats : PDF
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Numerical and experimental steady state investi...
- Author(s) : JALIL S. M., OKASHA A., GEBBIE J. G., MÜLLER N.
- Date : 2021/05
- Languages : English
- Source: 2021 Purdue Conferences. 18th International Refrigeration and Air-Conditioning Conference at Purdue.
- Formats : PDF
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New development of air cooled finned heat excha...
- Author(s) : FILIPPINI S.
- 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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