Entransy dissipation number and its application to heat exchanger performance evaluation

• Published in: Chinese science bulletin Vol. 54; no. 15; pp. 2708 - 2713
• Main Authors: Guo, JiangFeng, Cheng, Lin, Xu, MingTian
• Format: Journal Article
• Language: English
• Published: Heidelberg SP Science in China Press 01.08.2009
• Subjects: Articles/Engineering Thermophysics; Chemistry/Food Science; Earth Sciences; Engineering; Humanities and Social Sciences; Life Sciences; multidisciplinary; Physics; Science; Science (multidisciplinary); 传热能力; 基于特征; 性能评价; 换热器; 效率下降; 评价标准; entransy; entropy generation; entransy dissipation number; heat exchanger effectiveness
• ISSN: 1001-6538; 2095-9273; 1861-9541; 2095-9281
• DOI: 10.1007/s11434-009-0295-z

Based on the concept of the entransy which characterizes heat transfer ability, a new heat exchanger performance evaluation criterion termed the entransy dissipation number is established. Our analysis shows that the decrease of the entransy dissipation number always increases the heat exchanger effectiveness for fixed heat capacity rate ratio. Therefore, the smaller the entransy dissipation number, the better the heat exchanger performance is. The entransy dissipation number in terms of the number of exchanger heat transfer units or heat capacity rate ratio correctly exhibits the global performance of the counter-, cross- and parallel-flow heat exchangers. In comparison with the heat exchanger performance evaluation criteria based on entropy generation, the entransy dissipation number demonstrates some distinct advantages. Furthermore, the entransy dissipation number reflects the degree of irreversibility caused by flow imbalance.