车用扁管换热器凝结换热的试验研究

Experimental Investigation of Condensation Heat Transfer in Flat Tube Heat Exchanger

在管内流体流动状态处于过渡段并且未知扁管内壁温度的情况下,试验研究了扁管的凝结换热过程,采用线性回归方法拟合出换热系数与管内流体流速之间关系的曲线方程,并用测量值的方差检验其精度。研究结果表明:扁管长宽比越大,越有利于管内对流换热,却越不利于管外凝结换热。

The condensation heat transfer process of flat tubes was investigated under transitional conditions and unknowing inwall temperature.A linear regression was applied to fit the curve equation between heat transfer coefficient and in-tube flow rate,also the accuracy of the equation was verified by the variance of measured values.The experimental results show that larger aspect ratio would benefit the convective heat transfer inside the flat tube,but hinder the condensation heat transfer outside.A new method of the calculation of the heat transfer coefficient has been therefore offered by this thesis.