肋片能质传递效率研究

Investigation on Available Energy Transfer Efficiency of Fin

从能质传递的观点出发,依据热力学第一定律和第二定律,重新定义了肋片能质传递效率,即肋片的实际能质传递量与理想能质传递量之比,导出了肋片能质传递效率的计算式,并以工程中常见的针肋和对流换热介质空气为例,通过数值计算,分析了雷诺数、量纲一运行参数B、流体温度以及肋片结构尺寸等对肋片能质传递效率的影响,并与常规的肋片传热(能量传递)效率结果进行了比较,从而为工程中合理选择肋片的运行工况参数及结构参数提供依据。

Based on the first and second laws of thermodynamics, the fin efficiency, namely, the ratio of actual available energy transfer rate to ideal available energy transfer rate was defined and analyzed from the viewpoint of available energy transfer. The analytical expressions for the available energy transfer efficiency of fins were obtained. By reference to a constant cross sectional area fin type,i, e. pin fin,and taking air as a working medium, a numerical analysis of the influence of Reynolds number, non-dimensional operating parameter B, fluid temperature and fin geometry etc. on the available energy transfer efficiency of fins was discussed. Besides, the fin efficiency for available enengy transfer was compared with that for energy transfer. The results provided a reference to choose reasonable operating and geometric parameters of fin in engineering.