内螺纹管换热器的综合性能分析  

Comprehensive performance analysis of the heat exchanger with rifled tube

作　　者：申道明 桂超[1] 刘亚萍 夏锦红 薛松涛 Shen Daoming;Gui Chao;Liu Yaping;Xia Jinhong;Xue Songtao(College of Civil Engineering and Architecture, Xinxiang University, Xinxiang 453000, China;Research Institute of Structural Engineering and Disaster Reduction, Tongji University, Shanghai 200092;Department of Architecture, Tohoku Institute of Technology, Sendai, Japan 9828577)

机构地区：[1]新乡学院土木工程与建筑学院,新乡453000 [2]同济大学结构工程与防灾研究所,上海200092 [3]日本东北工业大学,日本仙台9828577

出　　处：《低温工程》2019年第5期14-20,74,共8页Cryogenics

基　　金：国家自然科学基金项目号(41877251)

摘　　要：对2种相同肋基管径,不同肋片螺旋角的内螺纹管进行流动冷凝换热实验分析,首先使用传热系数和换热温差、压降和摩擦因子对换热器换热性能和工质流动功耗进行单一性能评价,而后使用单位压降传热系数、系统熵增对换热器综合性能及换热过程中能量品质损耗进行研究。实验结果显示:换热温差越小则表示换热器换热性能越好,换热温差随饱和温度的降低、雷诺数的增加,肋片螺旋角的增大而减小;管内工质摩擦因子越大则流体流动压降越大,摩擦因子随着饱和温度的降低、雷诺数的增加,肋片螺旋角的增大而增加,换热量对摩擦因子、压降表现出不同影响效果,主要是由加速压降在总压降中所占比重的变化引起的;单位压降传热系数(HHP)随雷诺数Re的减小、饱和温度的降低、肋片螺旋角的增加而增大,HHP的变化趋势实际表征实验变量对换热系数和压降影响程度的相对大小;熵增主要表征换热过程中的不可逆损失,其与换热温差呈正相关,因此系统内换热熵增同样随饱和温度的降低、雷诺数的增加、肋片螺旋角的增大而减小。Two types of internal threaded tubes with identical fin base diameter and different fin helical angle were analyzed in the flow condensation heat transfer experiment. In the paper, heat transfer coefficient and heat transfer temperature difference, pressure drop and friction factor were firstly used to evaluate the heat transfer performance and flow power consumption of working medium, and then the heat transfer coefficient per unit pressure drop and entropy production were used to study the comprehensive performance of heat exchanger and energy quality loss in the heat transfer process. Experimental results show that the smaller the heat transfer temperature difference is the better the heat transfer performance of the heat exchanger is. The heat transfer temperature difference decreases with decreasing saturation temperature, increasing Reynolds number and fin helical angle. The larger the friction factor of working mediam in the tube,the greater the pressure drop of fluid flow. The friction factor increases with decreasing saturation temperature, increasing Reynolds number and fin helical angle.The heat transfer amount has different effects on the friction factor and pressure drop, which were caused by the change of the acceleration pressure drop proportion in total pressure drop. The heat transfer coefficient per unit pressure drop HHP increases with decreasing Reynolds number Re and saturation temperature and increasing fin helical angle. The change of HHP represents relative influence degree of experimental variables on the heat transfer coefficient and pressure drop and the entropy production represents irreversible loss in the heat transfer process, which is positively correlated with the heat transfer temperature difference, therefore, entropy increase also decreases with decreasing saturation temperature, increasing Reynolds number and fin helical angle.

关 键 词：内螺纹管 换热温差 摩擦因子 单位压降传热系数 熵增 

分 类 号：TB663[一般工业技术—制冷工程] TB657