基于[火积]理论的有机工质管壳式换热器构形优化  

Constructal optimization for an organic fluid shell-and-tube heat exchanger based on entransy theory

作　　者：冯辉君 陈林根 吴志祥 谢卓君[1,2,3] 夏少军 FENG HuiJun;CHEN LinGen;WU ZhiXiang;XIE ZhuoJun;XIA ShaoJun(Institute of Thermal Science and Power Engineering,Wuhan Institute of Technology,Wuhan 430205,China;School of Mechanical&Electrical Engineering,Wuhan Institute of Technology,Wuhan 430205,China;College of Power Engineering,Naval University of Engineering,Wuhan 430033,China)

机构地区：[1]武汉工程大学热科学与动力工程研究所,武汉430205 [2]武汉工程大学机电工程学院,武汉430205 [3]海军工程大学动力工程学院,武汉430033

出　　处：《中国科学：技术科学》2020年第12期1577-1587,共11页Scientia Sinica(Technologica)

基　　金：国家重点研发计划(编号:2017YFB0603503);国家自然科学基金(批准号:51779262,51506220)资助项目。

摘　　要：基于构形理论和[火积]理论,以传热[火积]耗散率和总泵功率组成的复合函数为优化目标,在总换热率和总传热面积一定的条件下,对管壳式换热器有机工质蒸发过程进行构形优化,得到最小复合函数和最佳换热管外径.结果表明:管壳式换热器最优构形与初始设计结构相比,传热[火积]耗散率和复合函数分别降低9.54%和1.56%,总泵功率增加22.40%.这说明换热器综合性能的提高是通过较大程度地降低流体流动性能和显著减小传热不可逆性来实现的.增大总换热面积和工质质量流率、减小工质进口温度以及选择合适的总换热管数和热水质量流率均有助于进一步提高换热器的综合性能.[火积]耗散率和泵功率复合函数最小的换热器最优构形与换热率和泵功率复合函数最小的最优构形是完全不同的.将[火积]理论应用到有机工质管壳式换热器的构形优化中,为其结构优化设计提供了新的指导.Based on constructal theory and entransy theory, constructal optimization of a shell-and-tube heat exchanger(STHE) for the organic fluid evaporation process is performed using a complex function as an optimization objective. The complex function is composed of the entransy dissipation rate(EDR) caused by heat transfer and the total pumping power. The total heat transfer rate and heat transfer area are taken as constraints in the optimization. The minimum complex function and optimal external diameter of the heat transfer tube can then be obtained. The results show that, compared to the initial design construct, the optimal construct of the STHE reduces the EDR caused by the heat transfer and complex function by 9.54% and 1.56%, respectively, and increases the total pumping power by 22.40%. This illustrates that an overall performance improvement of the STHE can be realized by substantially reducing the fluid flow performance and significantly decreasing the heat transfer irreversibility. The overall performance of the STHE can be further improved by increasing the total heat transfer area and the mass flow rate of the working fluid and decreasing the inlet temperature of the working fluid, as well as choosing an appropriate total number of heat transfer tubes and an optimal mass flow rate of the hot water. The optimal constructs of the STHE derived from the minimizations of the two complex functions, composed of the EDR and total pumping power, heat transfer rate and total pumping power, are obviously different. New guidelines for the optimal structure designs of STHEs are provided by introducing entransy theory into constructal optimizations of organic fluid STHEs.

关 键 词：构形理论 [火积]理论 管壳式换热器 [火积]耗散率 总泵功率 广义热力学优化 

分 类 号：TK172[动力工程及工程热物理—热能工程]