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为评价锅炉尾部烟道烟气流过H型翅片管省煤器时的积灰特性,使用Fluent软件对气固两相流绕流H型翅片管进行了冷态数值模拟。对颗粒相的计算采用单向耦合模型,忽略固相对气相的作用,在给定进口速度及烟气颗粒相质量浓度条件下,得到绕流流场。计算结果表明:颗粒速度在H型翅片管迎风面呈M型分布;背风面呈W型分布。H型翅片管开缝既可提高迎风面驻点附近速度,增强轴向吹扫分流,又可增大背风面的回流扰动。这种速度分布特点使H型翅片管不易积灰。在此基础上,模拟了不同入口流速和颗粒质量浓度时的工况,计算结果表明H型翅片管在高速高质量浓度下工作效果同样较好。
In order to evaluate the fouling characteristics when the flue gas flows through the H-fin tube economizer, the Fluent software is used to simulate the flow around the H-finned tube in gas-solid two-phase flow. For the calculation of particle phase, a unidirectional coupling model was used, ignoring the effect of solid phase on the gas phase, and the flow field was obtained under given inlet velocity and particle mass concentration of flue gas. The calculated results show that the particle velocity is M-shaped on the windward side of the H-finned tube and W-shaped on the leeward side. H-fin tube slit can increase the speed near the windward stagnation point, enhance the axial purge diversion, but also increase the leeward return flow disturbance. This speed distribution feature makes H-finned tube difficult to fouling. Based on this, the operating conditions of different inlet flow velocity and particle mass concentration were simulated. The calculation results show that the work efficiency of H-finned tube under high speed and high mass concentration is also good.