折流板结构对换热器壳程性能影响的对比研究

Comparison and Research of Effects of Baffle Structure to Characteristics of Heat Exchanger at Shell Side

建立弓形折流板、连续螺旋折流板和四分螺旋折流板换热器模型,采用CFD软件Fluent借助数值模拟的方法,定量对比分析3种折流板结构下换热器的流动和传热性能。结果表明：同连续螺旋折流板换热器相比,四分螺旋折流板换热器壳程进口段长度增加。相邻折流板间距为128.85 mm时,同螺距128.85 mm时螺旋角为20°的两种折流板结构的螺旋折流板换热器相比,弓形折流板换热器综合性能最差,四分螺旋折流板换热器其次,连续螺旋折流板换热器最高。其中,不同流态下,连续螺旋折流板换热器较四分螺旋折流板换热器壳程综合性能增加7.28%~11.05%,弓形折流板换热器同连续螺旋折流板换热器和四分螺旋折流板换热器相比,壳程综合性能分别降低23.62%~28.65%和15.37%~21.08%。

Based on the RNG k-ε model, flow and heat transfer characteristics of heat exchangers with segmental baffle, continuous helical baffle and quarter helical baffle were studied. Heat transfer coefficients, pressure drops and comprehensive performances of heat exchangers with three different baffle structures were quantitativelg compared. The results show： compared with the heat exchangers with continuous helical baffles, the length of shell side of heat exchangers with quarter helical baffles is greater. When the space of adjacent baffles is 128.85 mm, compared with the two structures of helical baffles of which the pitch of helical baffles is 128.85 mm and helical angle is 20°, the comprehensive performances of heat exchanger with segmental baffles appears the worst, next is one with quarter helical baffles, and the one with continuous helical baffles shows the best. Under different flow conditions, the comprehensive performances of heat exchanger with continuous helical baffles increased 7.28%~11.05% than that of ones with quarter helical baffles heat exchanger. And compared with the heat exchangers with continuous helical baffles and quarter helical baffles, the comprehensive performance of the heat exchanger segmental baffles with decreased 23.62% ~ 28.65% and 15.37% ~ 21.08%.