电除尘区低温省煤器烟道导流优化的数值模拟

为实现电除尘区低温省煤器的节能改造,利用FLUENT 6.3对电除尘区低温省煤器烟道的流场均化和导流优化设计进行了数值模拟研究.研究结果表明:电除尘区加装低温省煤器后烟道流场严重不均,存在回流和漩涡,局部速度高达26 m/s,最大速度偏差系数达90%,电除尘入口速度分布不均;导流板可有效改善烟道流场,削减回流与漩涡,换热管屏处速度偏差减小30%;电除尘入口烟气向下的平均速度分量由3 m/s削减至0.6 m/s,入口烟气分布趋向均匀;通过变工况数值分析,不同运行工况下的导流板作用变化不大,均具有良好的均流效果.此结果可为工程技术改造提供参考.

Numerical Simulation of Flue Diversion and Optimization of Low Temperature Economizers in the Electrostatic Precipitator Area

In order to optimize the velocity field,flue diversion and the design of low temperature economizers in the electrostatic precipitator（ESP） area for the energy-saving retrofit,the 3D flow in the flue system was simulated by FLUENT 6. 3. The simulation results show that the distribution of velocity field inside the flue is extremely uneven,there are refluxes and vortexes,the local maximum speed is 26. 0 m / s,the maximum speed deviation coefficient is almost 90%,the velocity field in the ESP＇s entrance is uneven. The results also indicate that the splitters can improve the distribution of the flow field in the flue,reduce the refluxes and vortexes,and there is a 30% decrease in the speed deviation at the heat transfer tube; the downward velocity of the gas decreases from 3. 0 m / s to0. 6 m / s,the gas speed distributes well at the entrance of the ESP. Through numerical experiments,the splitters work well in the diversion and optimization under different work conditions. The results can provide reference for the engineering reform.