泡沫金属与PVC材质冷却塔收水器的对比研究

Comparative Research of Foam Metal and PVC Cooling Tower Eliminator

收水器是冷却塔中重要飘滴控制部件,现有普通PVC收水器对细小液滴收集能力较差,文章对一种新型冷却塔收水器—泡沫金属收水器特性与普通PVC冷却塔收水器进行了计算流体力学对比研究。以欧拉—拉格朗日两相流为基础,建立冷却塔泡沫金属收水器与普通PVC收水器的三维稳态模型。考虑到泡沫金属收水器的多孔介质特性,泡沫金属收水器模型被划分为流体域和多孔介质域两个区域,普通PVC收水器只有流体域。两模型主要考虑了气—液两相间的曳力、重力和浮力的作用。湍流模型和涡流相互作用模型分别选用了剪切应力输运湍流模型(SST)和恒定涡流相互作用模型(constant EIM)。在不同气速下对两种冷却塔收水器内气体流动情况进行对比研究,结果表明由于惯性和过滤的双重作用,泡沫金属收水器具有内部气体分布均匀,涡漩少,细小液滴的收集效果好,不易夹带的优点。

Eliminator is a key drift control equipment of cooling tower.The common PVC eliminator has poor collection ability for small droplets.In this article,a novel cooling tower eliminator,metal foam eliminator,is compared with the common PVC cooling tower eliminator.Based on the Euler Lagrange two-phase flow,two three-dimensional steady state CFD model of the foam metal eliminator and PVC eliminator are established.Considering the porous medium characteristics of the metal foam eliminator,the foam metal eliminator model is divided into two domains:the fluid domain and the porous medium domain.The PVC eliminator only has fluid domain.The effects of drag,gravity and buoyancy are considered in these two models.The shear stress transport turbulence model(SST)and the constant eddy interaction model(constant EIM)are chosen as turbulence model and eddy interaction model respectively.The gas flow field of these two eliminators is compared at different gas speed.The results showed that the metal foam eliminator has the advantages of more uniform internal gas distribution,less vortex,and good collection effect of small droplets,for its unique droplets collecting combined inertia and filter principle.