圆形翅片导热的翅片效率

翅片管是翅片管换热器中的核心和关键元件,翅片效率是设计翅片管换热器过程中的主要参数之一,在换热表面的比较方面也具有一定的实用价值。由于翅片效率的解析解复杂或求解困难,对于一般工程问题只需求出近似值即可满足需要,所以采用了一种简便可行的数值法。根据热量衡算,建立了圆形翅片导热的数学模型,运用有限差分法,将模型整理为三对角矩阵,借助于计算机,计算出圆形翅片导热的温度分布,翅片散热速率,从而计算出翅片效率。根据实例所得出的翅片散热速率θ1为22.92W,翅片表面温度为基管温度时散热速率θ2为36.82W,所得翅片效率η为0.62。应用该方法可对不同结构尺寸、材质的圆形翅片及不同的换热介质进行计算,得出相应的结果。

Fin Efficiency of Round Fin Heat Conduction

A finned tube is the key component of a finned tube heat exchanger, and the fin efficiency is one of the main parameters in designing a finned tube heat exchanger, and it also has certain applicable value in the comparison of heat exchange surface. Since the analytic solution of fin efficiency is quite complicated or it is difficult to be computed that an approximate value could basically meet the requirement of a normal engineering calculation, the simplified feasible numerical method is applied for that. Basing on heat balance the mathematical model of heat conduction of the round fin was established with the change of the model to diagonal triangle matrix by finite-difference method. The temperature distribution, heat release rate and fin efficiency are figured out with a computer. From the actual example, the heat release rate θ_1 is 22.92 W, when the fin surface temperature is the same with the base tube, the heat release rate θ_2 is 36.82 W, and the fin efficiency η is 0.62. This calculation could be applied to round fins of different structure sizes, different materials and different working media.