新型水-汽板式换热器的冷凝除湿性能研究

Condensation and Dehumidification Performance of a New Type of Water-steam Plate Heat Exchanger

冷凝除湿在废水处理和石油化工等行业中应用较多,板式换热器因具有结构紧凑、单位体积内换热面积大、传热系数高等优点,逐渐在冷凝除湿环节得到应用。但由于板式换热器中流体流动和相变的复杂性,对其研究、计算和分析比较困难。利用试验和CFD数值模拟方法,研究了新型水-汽换热器不同结构参数的换热板对冷凝除湿性能的影响。结果表明,随着换热板波纹倾角的增大,流体边界层分离越来越明显,湿空气含湿量减小;随着换热板波纹高度的增大,流动死区减少,流体分布越来越均匀,冷凝除湿效果增强;随着换热板波纹间距的增大,换热板换热面积减小,扰流程度大大降低,湿空气冷凝除湿效果变差,但压降有效降低。

In wastewater treatment and petrochemical industries,condensation and dehumidification are often involved. Plate heat exchanger is gradually applied in the condensation and dehumidification process because of its compact structure,large heat exchange area in the unit volume and high heat transfer coefficient. However,due to the complexity of fluid flow and phase transition,it is difficult to study,calculate and analyze. The influence of heat transfer plate with different structural parameters on the performance of condensation dehumidification is studied by the combination of experiment and CFD numerical simulation. The results show that with the increase of heat transfer in wavy angle,boundary layer separation is more and more obvious,wet air has less moisture. With the increase of height of ripple,the flow dead zone is reduced,the fluid distribution is more uniform,The effect of condensation and dehumidification is enhanced. With the increase of the corrugation spacing,heat transfer plate the heat transfer area is reduced,turbulence degree is greatly reduced,and the effect of condensation and dehumidification becomes worse,but the pressure drop is effectively reduced.