螺旋椭圆管换热器传热特性与阻力特性研究  

Research on heat transfer and resistance characteristics of spiral oval tubes heat exchanger

作　　者：卫利峰 高文志[1] 李勇[1] 赵欣颖 WEI Li-feng;GAO Wen-zhi;LI Yong;ZHAO Xin-ying(State Key Laboratory of Engines,Tianjin University,Tianjin 300350,China)

机构地区：[1]天津大学内燃机燃烧学国家重点实验室,天津300350

出　　处：《化学工程》2019年第4期23-28,共6页Chemical Engineering(China)

基　　金：国家自然科学基金重点项目(51636005)

摘　　要：旨在研究螺旋椭圆管式换热器管内流动换热性能。借助CFD数值模拟方法分析了流体入口角度θ和椭圆截面长短轴之比a/b对螺旋椭圆管式换热器管内流动和换热的影响,并且利用综合传热增强因子PEC评价了换热器的综合换热性能。结果表明:螺旋椭圆管内存在二次流,导致螺旋椭圆管截面内温度梯度和速度梯度径向分布不均;在研究范围内,θ增大,努塞尔数Nu增加,摩擦系数f提高,综合换热性能增加;θ>45°时,螺旋椭圆管综合换热性能优于螺旋圆管。θ一定时,a/b越大,综合换热性能越好。通过对多种不同结构的螺旋椭圆管进行多工况数值模拟后,修正了现有的准则关联式,提高了准则关联式的准确度。Flow and heat transfer characteristics in helical oval tube were investigated.The effects of the inlet angleθand the ratio of major-minor axis a/b on flow and heat transfer in helical oval tube were researched by CFD numerical simulation.Comprehensive heat transfer performance was analyzed on the base of the performance evaluation criterion PEC.The simulation results indicate that the radial distribution of temperature and velocity in cross section is ununiform due to the secondary flow;in research scope,Nusselt number Nu,friction coefficient f and comprehensive heat transfer performance increase withθincreasing;whenθ>45°,the comprehensive heat transfer performance of helical oval tube is better than that of spiral circular tube.For constantθ,the comprehensive heat transfer performance increases with a/b increasing.Based on simulation data in various working conditions of different structures for helical oval tubes,the existing criterion correlation is corrected,and the accuracy of the criterion association is improved.

关 键 词：流动 传热 螺旋椭圆管 二次流 椭圆度 数值模拟 

分 类 号：TQ021.3[化学工程]