不同流动状态下98%硫酸的强化传热  

Heat Transfer Enhancement of 98% Sulfuric Acid in Different Flow States

作　　者：洪宇翔[1] 邓先和[1] 

机构地区：[1]华南理工大学传热强化与过程节能教育部重点实验室,广东广州510640

出　　处：《华南理工大学学报（自然科学版）》2011年第11期33-39,共7页Journal of South China University of Technology(Natural Science Edition)

基　　金：国家自然科学基金资助项目(20776046)

摘　　要：通过数值模拟,研究了98%硫酸在内插旋流片缩放管管内的传热与流阻特性,并与光滑管、缩放管空管的传热效果进行了对比,分析了不同流动状态和热物理性能对内插旋流片缩放管类换热器综合传热性能的影响,揭示了速度场与温度场之间的协同性.结果表明:层流时内插旋流片缩放管的综合传热性能优于缩放管空管,湍流时则相反;小扭率有利于内插旋流片缩放管层流综合性能的提高,大扭率则有利于湍流综合性能的提高;层流条件下内插旋流片对传热场的协同增强的作用显著,湍流条件下的作用不显著;内插旋流片缩放管类换热器对于低黏度与高黏度的工质均有较好的强化传热效果.In this paper,first,the heat transfer and flow resistance characteristics of 98% sulfuric acid in the converging-diverging tubes inserted with twisted tapes are numerically simulated,and the corresponding heat transfer effect are compared with that in the smooth tube and in the single converging-diverging tube.Then,the effects of flow state and thermal physical property on the comprehensive heat transfer performance of the converging-diverging tubes inserted with twisted tapes are analyzed,and the field synergy between velocity and heat flow fields is discussed.The results indicate that the comprehensive performance of the converging-diverging tubes inserted with twisted tapes are higher than that of the single converging-diverging tube under laminar flow,while are lower under turbulent flow,that small twist ratio of twisted tapes is beneficial to the improvement of the comprehensive performance under laminar flow,while large twist ratio is beneficial under turbulent flow,and that the synergetic enhancement of the heat transfer by the twisted tapes is more significant under laminar flow than that in turbulent flow.In addition,in heat exchangers of converging-diverging tubes inserted with twisted tapes,the fluids with low and very high viscosity are of better heat transfer performance than that with medium viscosity.

关 键 词：强化传热 缩放管 旋流片 硫酸 场协同 

分 类 号：TK124[动力工程及工程热物理—工程热物理]