Optimization for entransy dissipation minimization in heat exchanger

• Published in: Chinese science bulletin Vol. 54; no. 19; pp. 3587 - 3595
• Main Authors: Xia, ShaoJun, Chen, LinGen, Sun, FengRui
• Format: Journal Article
• Language: English
• Published: Heidelberg SP Science in China Press 01.10.2009
• Subjects: Articles/Engineering Thermophysics; Chemistry/Food Science; Earth Sciences; Engineering; Humanities and Social Sciences; Life Sciences; multidisciplinary; Physics; Science; Science (multidisciplinary); 有限时间; 热力学; 物理学; optimal control; finite time thermodynamics; heat exchanger; entransy dissipation
• ISSN: 1001-6538; 2095-9273; 1861-9541; 2095-9281
• DOI: 10.1007/s11434-009-0299-8

A common of two-fluid flow heat exchanger, in which the heat transfer between high- and low-temperature sides obeys Newton＇s law [q∝△（T）], is studied in this paper. By taking entransy dissipation minimization as optimization objective, the optimum parameter distributions in the heat exchanger are derived by using optimal control theory under the condition of fixed heat load. The condition corresponding to the minimum entransy dissipation is that corresponding to a constant heat flux density. Three kinds of heat exchangers, including parallel flow, condensing flow and counter-flow, are considered, and the results show that only the counter-flow heat exchanger can realize the entransy dissipation minimization in the heat transfer process. The obtained results for entransy dissipation minimization are also compared with those obtained for entropy generation minimization by numerical examples.