基于(火积)理论的热系统分析和优化的能量流法  

Entransy-based Power Flow Method for Analysis and Optimization of Thermal Systems

作　　者：陈群[1] 郝俊红[1] 付荣桓[1] 王怡飞[1] 赵思玉 赵甜[1] 

机构地区：[1]清华大学工程力学系热科学与动力工程教育部重点实验室,北京100084

出　　处：《工程热物理学报》2017年第7期1376-1383,共8页Journal of Engineering Thermophysics

基　　金：国家重点研发计划(No.2017YFB0902100);国家自然科学优秀青年基金(No.51422603)

摘　　要：熵产、炳损最小等准则函数法及传统能量流法是热系统性能优化的常用方法,但这些方法难以整体揭示热系统中的部件特性和拓扑特征,增加了系统整体分析和优化的难度。本文基于(火积)理论,利用流体进口温差(或算数平均温差)为特征温差重新定义了换热器的热阻,揭示了热量输运中驱动力和阻抗的本构关系,提出了换热器稳态性能分析的能量流法。在此基础上,针对双回路热管理系统,根据其拓扑特征及换热器的热阻构建了系统的能量流模型;基于基尔霍夫定律,揭示了系统中包含传递和输运两种阻力的热量整体输运规律。最后,应用拉格朗日乘子法优化该系统,获得了系统中换热器的最小总热导及热容量流的最佳分配,说明了本文基于(火积)理论提出的新能量流法在热系统分析和优化中的先进性。The criterion functions,such as entropy production and exergy loss minimum,and the traditional energy flow method are widely applied in performance optimization of thermal systems.However,these methods can not directly and simultaneously reveal the component performance and topological characteristic of a thermal system,which increase the difficulty in thermal system analysis and optimization.Based on the entransy theory,this paper redefines the thermal resistance of a heat exchanger by selecting the inlet or the mean averaged temperature difference of fluids as the characteristic temperature difference,discovers the constitutive relation of driving force and resistance during a heat transfer process,and finally developed the power flow method to analyze the steady-state performance of heat exchangers.For a double-loop thermal management system,the corresponding power flow model is built based on the system topology and the thermal resistances of each heat exchanger,which describes the overall heat transport law in the system by the aid of the Kirchhoff＇s law.Moreover,the Lagrange multiplier method is used to minimize the total thermal conductance of all heat exchangers and obtain the corresponding optimal heat capacity rates of each fluid,which shows the superiority of the newly proposed entransy-based power flow method.

关 键 词：热系统 性能优化 能量流 热阻 (火积)理论 

分 类 号：TK124[动力工程及工程热物理—工程热物理]