相变换热系统的能量流模型及其应用  

Energy Flow Model for Heat Transfer Systems With Phase Change Fluids and Its Applications

作　　者：陈曦[1] 齐腾云 蒋春涛 钟英彪 赵思玉 陈群[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 [2]中电国际新能源控股有限公司,上海200086 [3]东莞中电新能源热电有限公司,东莞523127

出　　处：《工程热物理学报》2017年第3期600-606,共7页Journal of Engineering Thermophysics

基　　金：国家自然科学基金(No.51422603);国家科技支撑计划(No,2015BAA01B03)

摘　　要：工质在换热过程中发生相变时,其物性参数将发生剧烈变化,增大了换热系统性能分析和优化的复杂度。本文以顺流、逆流和叉流三种典型换热器为研究对象,在考虑工质发生相变的前提下,构建了与其对应的等效热阻网络图(能量流模型),获得了换热器的换热量与结构/运行参数以及工质物性间的直接物理联系。以此为基础,对于含相变工质的换热系统,通过构建其整体能量流模型,结合基尔霍夫电压、电流定律明确了系统中各独立设计参数间的整体约束关系,并应用拉格朗日乘子法实现了相变换热系统的性能优化。Phase change of working fluids during heat transfer processes leads to drastic variation of fluid properties,which makes the heat transfer analysis and optimization much harder.This study first introduced the equivalent thermal circuit diagrams,i.e.energy flow models,and deduced the mathematical relations among the design requirements,structural and operating parameters and fluid properties for parallel-flow,counter-flow and cross-flow heat exchangers with phase change fluids.On this basis,we constructed the energy flow model for a multi-loop heat exchanger network（HEN） with phase change fluids and then clarify the integral relations among each independent design parameter of the HEN with the aid of Kirchhoff＇s voltage and current laws.Finally,by applying the Lagrange multiplier method,the performance of the multi-loop HEN was analyzed and optimized to show the applications of the newly proposed energy flow model.

关 键 词：换热系统 相变 能量流模型 (火积)耗散热阻 性能优化 

分 类 号：TK121[动力工程及工程热物理—工程热物理]