Abstract: Experimental study was conducted in trisection helical baffle heat exchangers with three sector baffle schemes of tilt angles 10°,15° and 20°,an ellipse baffle scheme of tilt angle 15°,and an axial overlap sector baffle scheme of tilt angle 20°,in contrast to a segmental baffle heat exchanger. Each helix heat exchanger has 48 tubes with layout of one third division of shell cylinder for each baffle, while the segmental baffle heat exchanger has 49 tubes. The data of the shell side, Nusselt number Nu_o, axial Euler number Eu_z,o, and comprehensive performance indicator Nu_o/Eu_z,o are presented versus the shell side axial Reynolds number Re_z,o. The results show that the heat exchanger with the scheme of periphery connected sector baffles with tilt angle of 20° has the best performance, whose average comprehensive performance indicator Nu_o/Eu_z,o is 69.8% higher than that of segmental baffle heat exchanger, while the comprehensive performance indicator of the scheme with tilt angle 10°is lower than that of segmental baffle scheme. With the same tilt angle, the performance with the periphery connected connection baffle scheme is better than that with the axial overlap baffle scheme, and the performance with the sector baffle scheme is better than that with the ellipse baffle scheme.

Key words: helical baffle heat exchanger；trisection helical baffles；tilt angle, comprehensive performance indicator

摘要： 对倾斜角为10°、15°和20°的扇形折流板，倾斜角为15°的椭圆折流板和倾斜角为20°的轴向搭接扇形折流板三分螺旋折流板换热器以及弓形折流板换热器的传热特性和压降性能进行了测试试验研究，其中螺旋折流板全部采用分区布管结构，有48根管子，而弓形折流板换热器有49根管子。试验数据分析采用轴向Reynolds数Re_z,o作为自变量，壳侧Nusselt数Nu_o、轴向Euler数Eu_z,o等参数作为因变量，并采用Nu_o/Eu_z,o量纲1组合数作为综合性能指标。在试验范围内，20°s方案的综合性能指标最高，比弓形折流板换热器方案平均提高69.8%；倾斜角最小的10°s方案的综合性能低于弓形折流板换热器方案；轴向搭接折流板换热器方案的综合性能低于相同倾斜角外圈连接折流板换热器方案，而椭圆折流板方案的综合性能低于相同倾斜角的扇形折流板方案。

关键词: 螺旋折流板换热器, 三分螺旋折流板, 倾斜角, 综合性能