不同进风条件下翅片管换热器传热和压降特性的实验研究

摘要

The performances of heat transfer and pressure drop of the fin-tube heat exchangers with the different inclination angles are experimented with the conditions of free and restricted air inlet. Five kinds of the different middle temperature of water are chose for the experiments. The experiment results show that the impact by inlet air condition and inclination on heat transfer coefficient is great. The heat transfer under the positive inclination angle is greater than that under the negative inclination angle. The heat transfer under free air inlet is better than that under restricted air inlet when the inclination angle is positive, but the result is contrast when the inclination angle is negative. The influence of inlet air angle on heat transfer coefficient can be neglected when the inclination angle is the same. The pressure drop is varied with the inclination angle but it isn＇t affected by the inlet air condition and duct. The pressure drop is increased with the increasing of the outlet inclination angle.%针对不同倾斜角度的翅片管换热器，本文研究其在自由进风及受限进风条件下的换热及压降特性。针对各种倾斜角度，本文分别在自由及受限进风情况下，通过每组5个不同中心水温的实验进行研究。实验结果表明，换热系数受进风条件以及换热器倾斜角度的影响较大。正的倾斜角度的换热效果优于负的倾斜角度。在正倾斜角度下，自由进风的换热效果又优于受限进风，负倾斜角度结果恰恰相反，但是同一倾斜角度下的换热器换热系数受进风角度的影响很小。换热器空气侧的压降只与换热器的倾斜角度有关，基本不受风管存在与否的影响，并且进风角度的不同对其也无影响；换热器的倾斜角度越大，压降越大。