内置弧形槽扭旋元件圆管中湍流传热特性研究

Study on Turbulent Heat Transfer Characteristics in Circular Tube With Built-in Arc Groove Torsional Element

设计出一种新型强化换热元件--弧形槽扭旋元件,并在Re=4000~10000范围内对三种弧形槽数量的扭旋元件进行了数值模拟,从平均努塞尔数、温度场分布等方面分析了弧形槽的数量对管道传热特性的影响。模拟结果表明,n=3元件弧形槽的数量和分布位置有利于中心流体与管壁附近流体的混合以此强化传热,在三种元件中具有最佳的换热效果,n=2元件次之,n=1元件的结构不利于槽内流体与外界流体的交汇,换热效果较弱;三种元件引起的管道阻力随弧形槽数量的增加而提升,综合传热性能方面,PEC值均大于1,最大值为n=3元件在Re=4000时,达到1.33,说明使用弧形槽扭旋元件会使管道传热性能得到不同幅度的提升。

A new type of enhanced heat exchange element-arc groove torsional element was designed,and the torsional elements with three kinds of arc grooves were numerically simulated in the range of Re=4000~10000.The influence of the number of arc grooves on the heat transfer characteristics of the pipeline was analyzed from the aspects of average Nusselt number and temperature field distribution.The simulation results showed that the number and distribution position of n=3 element arc-shaped grooves were conducive to the mixing of the central fluid and the fluid near the pipe wall,so as to strengthen the heat transfer.Among the three elements,n=2 element had the best heat transfer effect,followed by n=2 element.The structure of n=1 element was not conducive to the intersection of the fluid in the groove and the external fluid,and the heat transfer effect was weak;The pipe resistance caused by the three elements increased with the increase of the number of arc grooves.In terms of comprehensive heat transfer performance,the PEC value was greater than 1,the maximum value was 1.33 when n was 3 and Re was 4000,indicating that the use of arc groove torsional elements improved the heat transfer performance of the pipe by different extents.