交错式涡流杆的传热强化作用和阻力特性

Heat Transfer Enhancement and Flow Resistance Characteristics of Staggered Vortex Rods

采用CFD数值计算方法,以水为工作介质,研究了涡流杆间距、杆长等结构和流动参数对强化管层流传热和阻力性能的影响规律。结果表明,内置交错涡流杆强化管可以使流体形成显著的径向涡流,雷诺数Re为300~1 800时,其努塞尔数和摩擦因子分别为光滑圆管的1.28~5.11倍和2.71~9.81倍,综合传热性能评价因子η为0.95~2.82。减小涡流杆间距、增加杆长均能够提高强化管的综合传热性能。

In this paper,using CFD numerical method,water-air as heat transfer system and water as fluid in tube,the rules of effecting laminar heat transfer and flow resistance in enhanced tubes by the structural parameters such as the spacing of staggered vortex rods and the length of rods and flowing parameters were investigated.It was shown from the results that strong radial swirling flows were introduced by staggered vortex rods;when Re number is 300 to 1 800,the Nu number and friction factor will be 1.28～5.11 times and 2.71～9.81 times of the original values,and the comprehensive heat transfer evaluating factor will be 0.95～2.82.Both of reduction of the spacing of vortex rods and the increasing of rod length are beneficial to comprehensive heat transfer characteristics.