螺旋槽管强化传热机理及性能的数值研究

基于Fluent对9根具有不同结构参数的单头螺旋槽管进行了数值研究,得到了螺旋槽管内流体速度和温度分布,从微观上说明了螺旋槽管强化传热的机理。数值计算结果表明,在研究的雷诺数Re范围内(10 000~45 000),螺旋槽管的努塞尔数Nu是光管的1.34~2.01倍;阻力系数f是光管的2.01~6.40倍;Nu和f随槽深e的增加而增加,随节距p的增大而减小。螺旋槽管传热的综合性能明显优于光管,在换热面积和泵功率消耗相同的情况下,综合性能最好的2#管可使换热量提高14%~19%。

Numerical study on mechanism and characteristic of heat transfer enhancement of spirally fluted tube

In this paper, nine single start tubes with different structural parameters were studied numerically based on Fluent. The velocity and temperature distributions in the tubes microeosmically revealed the mechanism of heat transfer enhancement. According to the result of numerical calculation, in the range of Re= 10 000~45 000, the Nusselt number Nu of spirally fluted tube is 1.34 to 2.01 times that of the smooth tube, and resistance coefficient f is 2.01 to 6.40 times that of the smooth tube. Nu and f increase as e increases, and decrease as p increases. The comprehensive performance of the tube is obviously better than that of smooth tube. Number two tube which has the best comprehensive performance can increase heat flux by 14% -19% in the condition of equal heat transfer area and pump power.