螺旋扭曲管内部流动与传热特性试验研究

Experimental Research on The Flow and Heat Transfer Characteristics of Twisted Oval Tube

螺旋扭曲管是一种新型的强化传热元件,具有传热效率高、流动阻力小等优势,在石油化工、船舶、采矿、动力以及钢铁行业中具有广泛的应用前景。采用试验的方法,研究了螺旋扭曲管管内在湍流(Nu>20 000)范围内的流动与强化传热特性,并与同规格的光滑圆管进行了比较。试验结果表明,在相同的Re数下,螺旋扭曲管管内Nu数大于光滑圆管,增大了约30%~50%,表明螺旋扭曲管能有效地提高管内对流换热效果;在相同的Re数下,螺旋扭曲管阻力因子比光滑圆管小;在相同的流量下,螺旋扭曲管管内阻力损失与光滑圆阻力损失基本相当,表明采用螺旋扭曲管不会显著的增加摩擦阻力。

The twisted tube is a new type heat transfer enhanced tube,which has the advantages of high heat transfer efficiency and low flow resistance.It has a broad application prospect in petrochemical,shipbuilding,mining,power and steel industries.The flow and heat transfer enhanced characteristics of twisted oval tube and smooth tube in the turbulent(Re>20000)range were studied experimentally in this paper.With the same Re number,the Nu number in the twisted oval tube is 30%to 50%higher than that in the smooth tube,which indicates that the twisted oval tube can improve the convective heat transfer;With the same Re number,the internal resistance coefficient of twisted oval tube is smaller than smooth tube;With the same volume flow rate,the pressure drop in the twisted tube is basically equivalent to that in the smooth tube,indicating that the use of twisted oval tubes will not increase the flow resistance significantly.