袋式除尘器入口烟道流场数值模拟与优化设计

Numerical simulation and optimizing design in inlet flue of bag filter

采用计算流体动力学(CFD)方法,对某热电厂350 MW机组袋式除尘器入口烟道及除尘器内部的气流流场分布进行了数值模拟实验研究。识别了原烟道设计结构存在的问题,分析了造成各除尘器单元流量分配不均匀和除尘器喇叭口进口断面速度分布不均匀的原因,并提出了改变进口烟道形状,在入口烟道布置导流板的优化方案。经过模拟仿真对比,优化后并联的5个除尘器单元流量分配不均匀性得到明显改善,最大流量偏差由10.79%减小至-2.29%,且5个喇叭口进口断面速度相对均方根值均不大于0.25,满足技术规范要求。

The air distribution of the inlet flue of a bag filter used in a 350 MW thermal power plant was numerically simulated using computational fluid dynamics （CFD）. The problem of original structure and the causes of the non-uniform gas flux distribution and uneven gas velocity distribution in the inlet flue section have been analyzed. Changing the shape of the inlet flue and installing a baffle plate have been proposed as the optimization scheme. In comparison with original structure, the optimization decreased the relative difference of the gas flux in five bag filters from 10.79% to -2. 29%. The root mean square values of the gas velocity distribution in the inlet section did not exceed 0.25. The optimized results satisfy the technical requirements.