三分螺旋折流板换热器壳侧换热系数的关联式

对三分螺旋折流板换热器和对比方案弓形折流板换热器的传热和压降性能进行实验测试,其中,三分螺旋折流板换热器包括倾斜角分别为10,°15,°20°的扇形折流板,倾斜角为15°的椭圆折流板和倾斜角为20°的扇形搭接折流板5种方案.实验结果表明,20°倾斜角扇形折流板方案的壳侧换热系数最高且压降较低;折流板轴向搭接方案并不合理;当量螺旋角对换热器的性能起决定作用.根据实验数据拟合出含有倾斜角修正因子的三分螺旋折流板换热器壳侧换热系数的关联式,所计算的10,°15°和20°扇形折流板方案的数值与实验值相比误差大多小于±10%.

Correlation equation of heat transfer coefficient at shell-side of trisection baffled helix heat exchangers

The experimental results of the heat transfer and pressure drop performances of trisection baffled helix heat exchangers with inclined angles of 10°, 15° and 20° (sector baffles), 15° (ellipse baffles), and 20°(overlap sector baffles) are presented. As a compassion scheme the results from a segmental baffled heat exchanger are also provided. The results show that the scheme with 20° sector baffles inclined angle has the highest shell side heat transfer coefficient and low pressure drop; the scheme of axial overlap baffled helix heat exchanger is not reasonable; the decisive factor to the per-formance is the equivalent helix angle. The correlation equation is obtained including inclined baffle angle correction factor for shell-side heat transfer coefficient of trisection baffled helix heat exchang-ers, and the deviation errors between the majority of the results of both calculation and experiment are less than ± 10%.