接触热阻对双H型鳍片管传热系数的影响  

Impact of Thermal Contact Resistance on Heat Transfer Coefficient of Double H-Type Finned Tubes

作　　者：葛铭[1,2] 赵利杰 舒少辛 张守玉[1] 吕俊复[2] 

机构地区：[1]上海理工大学能源与动力工程学院,上海200093 [2]清华大学热能工程系,北京100084 [3]江苏海德节能科技有限公司,江苏无锡214215

出　　处：《中国电力》2017年第2期57-63,共7页Electric Power

基　　金：国家重点基础研究发展计划(973计划)资助项目(2012CB214904)~~

摘　　要：对2种常用的双H型鳍片管换热管束(ND钢和316L不锈钢)进行了实验研究,得到2种材料的实际传热系数。同时,将接触热阻考虑到鳍片效率中,推导得到了双H型鳍片管传热系数的计算模型,并通过实验验证了模型的准确性。实验发现,在焊接工艺和结构尺寸等因素相同的条件下,ND钢试样的传热系数远大于316L试样。根据实验值与计算值的差值,可以得到各试样的接触热阻值。对比2组试样的接触热阻值发现,ND钢试样的接触热阻远小于316L不锈钢试样。对于特定结构的双H型鳍片管,接触热阻导致316L试样传热系数下降了7 W·(m^2·K)^(-1),而对ND钢试样传热系数的影响却可以忽略不计。同时,对计算模型分析可知,当单位接触热阻小于0.001 m^2·K/W量级时,其对传热系数的影响基本可以忽略不计,验证了实验结果。计算模型可以预测特定结构鳍片管的接触热阻,从而判断接触热阻对传热系数的影响,为工业上选取合适的低温省煤器换热管束材料和焊接技术提供参考。The actual heat transfer coefficients of two commonly-used double H-type finned tubes （ND steel and 316L stainless steel） are obtained through experimental study. A computational model of the overall heat transfer coefficient with the thermal contact resistance being incorporated into the fin efficiency is proposed, and the accuracy of the proposed model is validated through the experiments. The experiments show that the overall heat transfer coefficient of Sample ND is much bigger than that of Sample 316L under the condition of the same manufacturing technology and the same structural dimensions. From the difference between the experimental and the calculated data, the thermal contact resistance of each sample are obtained. By comparing the two samples, it is found that the thermal contact resistance of Sample ND is far less than that of Sample 316L. In addition, for the special double H-type fins, the thermal contact resistance decreases the coefficient of Sample 316L by 7 W/（m2. K） while its impact on Sample ND can be ignored. Meanwhile, the analysis of the computational model shows that when the unit thermal contact resistance is less than 0.001 m^2·K·W^-1, its impact on the coefficient is too little to be counted, which proves the results of the experiments. The computational model can be used to predict the thermal contact resistance of finned tubes with special structures so as to determine the influence of the thermal contact resistance on the overall heat transfer coefficient. The study result can provide a reference on the selection of the materials and welding technologies for low-temperature economizer tube bundles in industrial applications.

关 键 词：低温省煤器 双H型鳍片管 传热系数 接触热阻 实验研究 

分 类 号：TK223.33[动力工程及工程热物理—动力机械及工程]