实验研究了安装有7种不同类型(小方槽、大方槽、平板、45°平板、小叉、半圆、三角)扰流内构件的管式换热器气相压降特性。研究结果表明,当气速小于某一特定值时,压降随着气速的增大而缓慢增加;当气速大于某一特定值时,压降随着气速的增大而明显增加。插入扰流内构件时,压降随着插入的扰流内构件数量增加而增大。其中,在相同条件下将平板结构的内构件扭转45°后压降相对降低,具有进一步深入研究的价值。根据实验数据,运用多元线性回归方法拟合得到了相应的压降关联式,以便于比较安装有不同结构内构件时雷诺数对管式换热器压降特性的影响程度,所拟合的压降关联式误差在±15%范围内。
Characteristics of pressure drop of the tube heat exchangers(THE) with seven types of inserted components,including small slot,big slot,plate,plate with turned angle of 45°,fork,semi-circle and triangle types,respectively,were studied.Experimental results show that the pressure drops increase slowly with the increases of gas velocity in a certain range(the range is different for different types of inserted component),and then the pressure drops increase obviously when the gas velocity increases further.The pressure drops increase steadily with the increase of the amount of inserted components.Especially,under the same condition,the pressure drop of the THE inserted plate-type component with turned angle of 45° is lesser than those inserted plate-type component without turned angle;the further research on the pressure drop of this type of component with a certain turned angle was recommended.Finally,in order to reflect the influence of Reynolds number on the pressure drop of THE with different inserted components,according to experimental data,the correlations of the pressure drop with Reynolds number were developed by using the multiple linear regression technique.Compared with the experimental data,the deviations of data predicted from the correlation are in the range of ±15%.