格栅型煤粉分配器气固两相流的数值模拟

Numerical Simulation of Gas-solid Two-phase Flow in Grille Pulverized Coal Distributor

为掌握煤粉分配器内气固两相流的流动特性,降低风粉偏差,利用计算流体软件Fluent对格栅型煤粉分配器进行数值模拟,分析内部结构对分配器出口流动偏差和压降的影响,提高锅炉运行效率,减少污染物排放,为锅炉的经济、稳定运行提供指导。结果表明,格栅两侧壁面受到冲刷严重;内部流动向外侧分支管倾斜;随着格栅数目的增加分配器的流动阻力逐渐增大,当格栅数目增加到一定数量(8个)后,出口偏差不再减小;格栅的交错顺序影响分配器内部流动,且第一级格栅对第二级格栅的流动产生很大影响。

In order to master the flow characteristics of gas - solid two - phases flow in the pulverized coal distributor, and to reduce the deviation of wind and powder, using the commercial software Fluent to nu- merically simulated grille pulverized coal distributor and analyzed the influence of internal structure to im- prove the efficiency of boiler and to reduce pollutant discharge, so that it can improve the guidance for e- conomic and the stable operation of the boiler. The results show that the grille on both sides of the wall was scoured severely and the internal flow inclined to the outside branch pipe. With the increase of grid number, the flow resistance of distributor increased gradually. When the number of grill reached a certain number, the deviation would no longer be decreased. The staggered sequence of grille affected the inter- nal flow of distributor. What＇s more, the first level of grille had a great impact on the flow of the second level.