圆形流道内置扭带强化传热机理分析

Analyses on Enhanced Heat Transfer Mechanism of Round Tube with Twisted Tape Inserts

为了分析圆形管道内置扭带的强化传热机理,用Fluent软件建立了其三维模型,模拟得到了管内流场和温度场,运用场协同原理证实了扭带强化传热的主要机理是扭带引起的螺旋流动使流体产生二次流,促进了主体流体和边界层流体的混合,提高了流场和温度场的协同性。分析了传热系数、压降与雷诺数及湍流动能的关系,提出应使换热器的湍流动能限制在一定的范围内,以获得较好的综合性能。

In order to analyze the enhanced heat transfer mechanism of round tube with twisted tape inserts, its three - dimensional model is estabished with FLUENT software, and flow and temperature field are simulated. Based on the field coordination theory, enhanced heat transfer mechanism of twisted tape inserts is confirmed. The secondary flow caused by helicoidal flow in a tube with twisted tape inserts can promote fluid mixing between main body and boundary, and enhance the synergy degree between the flow field and temperature field. The relation between heat transfer coefficient, pressure drop and Reynolds number, turbulent kinetic energy is analyzed. It is proposed that in order to obtain better integrated property the turbulent kinetic energy and Reynolds number should be confined in a certain range,