三维内肋管紊流换热和阻力特性的试验研究

以空气为工质,利用正交实验设计研究了雷诺数在25 000~110 000范围内的9种大管径三维内肋管的紊流换热和流动特性,优选出最佳管型,并得出努谢尔特数与范宁摩擦系数关于雷诺数和三维管肋参数的实验关联式。结果表明,三维内肋管的综合特性优于相同管径的光管,换热系数最高可达光管的3.15倍,热力性能系数最高可达光管的1.45倍,表明了大管径三维内肋管在管式换热器中运用的可行性;此外,各主要参数中,肋高对流动换热特性的影响最大,肋间距次之,肋宽最小,为强化管参数提供了优化方向。

Experimental Study on Turbulent Heat Transfer and Resistance Characteristics of Three Dimensional Internally Finned Tubes

Using air as working medium, the orthogonal experiment was used to study heat and flow characteristics of turbulent flow in nine kinds of big diameter three-dimensional internally finned tube while the Reynolds number within the range of 25 000~110 000 to select the best type tube, and to obtain the experimental correlations of Nusselt number and the fanning friction factor with Reynolds number and parameters of three-dimensional internally finned tube.Results show that characteristics of three-dimensional internally finned tube is better than that tube of the same diameter, heat transfer coefficient up to three point one five times that of the light tube and thermal performance coefficient up to one point four five times, which indicates the feasibility of application in tubular heat exchanger;In addition, the biggest impact on thermal heat transfer characteristics is the rib height, spacing comes second, width is the smallest, which shows the direction of parameter optimization.