A New Method for Analyzing Heat Exchangers- Matching of Temperature Field  

作　　者：WANG HuanGuang HUAI XiuLan 

机构地区：[1]Institute of Engineering Thermophysics, Chinese Academy of Sciences, Beijing 100190, China [2]University of Chinese Academy of Sciences, B eijing 100049, China

出　　处：《Journal of Thermal Science》2012年第5期452-458,共7页热科学学报（英文版）

基　　金：supported by the National Basic Research Program of China"973"Program)(Grant No.2011CB710705);the strategic priority research program of the Chinese Academy of Sciences(Grant No.XDA03010500)

摘　　要：In heat exchangers, the magnitude of Nu of each duct is influenced by the temperature field, since the ratio of heat capacity rate will influence the matching status of the temperature field between contacting ducts, the total heat transfer coefficient is related with the ratio of heat capacity rate. Considering this relationship, a new method for analyzing heat exchanger is proposed - matching of temperature field. First, for a single duct with the temperature field varying exponentially along the flow direction, its Nu is calculated. Then under the hypothesis that the thermal resistance of the wall is negligible, the matching condition was set like this: both the temperature and heat flux are equal for the hot and cold fluids at the wall, so the matching relationship of parameter that describes the temperature field of the hot and cold fluids, was obtained. Finally the relationship between the total Nu and the ratio of heat capacity rate along with the ratio of inherent thermal resistance is obtained. Compared with traditional analyzing methods, the temperature matching method can be used to get the total heat transfer coefficient directly, and also be used for optimization of heat exchanger design. For a parallel flow, the optimal ratio of heat capacity rate is reciprocal to the ratio of inherent thermal resistance, and for a counter flow, the optimal ratio of heat capacity rate is zero or infinity.

关 键 词：matching method heat exchanger ratio of heat capacity rate ratio of inherent thermal resistance 

分 类 号：TP273[自动化与计算机技术—检测技术与自动化装置] TK124[自动化与计算机技术—控制科学与工程]