新型六分扇形螺旋折流板换热器壳程传热及流动特性

Heat transfer and fluid flow on shell-side of heat exchangers with novel sextant sector helical baffles

针对现有四分螺旋折流板换热器中心区域漏流明显的特征,提出了一种新型的六分扇形螺旋折流板换热器。建立了六分扇形螺旋折流板换热器的三维物理模型,应用Ansys CFX软件对其壳程流动与传热特性进行数值模拟,分析了不同螺旋角(10°、20°、30°、40°)和不同工况下六分扇形螺旋折流板换热器的壳侧性能,并与传统的弓形折流板换热器作对比。结果表明,六分扇形螺旋折流板可以显著减少三角区漏流现象的发生,壳程流体旋流特性较好。随着螺旋角的增大,壳侧速度场与温度场分布更加均匀,综合换热性能逐步提高。

Faced with the obvious leakage flow phenomena in the heat exchanger with quarter helical baffles,a novel sextant helical baffled heat exchanger was put forward in this paper.The 3-dimensional physical model of sextant helical baffled heat exchanger was built;numerical simulation was performed with different helical angles（10°,20°,30°,40°）under different working conditions.ANSYS CFX software was used to obtain detailed fluid flow and heat transfer characteristics on the shell-side,and comparison was made between the new and the traditional segmental baffled heat exchangers.Results indicate that the leakage flow is significantly reduced with the sextant helical baffles,and shell-side rotational flow characteristics are also improved.As the helical angle increases,the velocity field and the temperature field become much uniform,so the comprehensive heat transfer performance is improved.