除尘器前烟道数值模拟和优化设计

The Numerical Simulation and Optimization Design to Upstream of ESP Dust

烟气通过除尘器前烟道从锅炉离开进入除尘器。对于大型火电机组,锅炉烟气出口通常为两个,而除尘器入口为4个,如何合理地设计除尘器前烟道结构,保证烟气分配的均匀性,并尽量减少烟气流动阻力,是烟道设计的核心问题。通过数值模拟,分析了目前应用较广的y形除尘器前烟道内烟气流动特性,并提出优化改进措施。研究发现,y形烟道分流位置的结构对流动分配影响较大,Z形组合弯头的阻力较高。适当增加导流措施,可有效提高烟气进入除尘器分配的均匀性,并减少流动阻力。

The flue gas goes into ESP through the upstream ESP duct.For the large thermal power plants,there are usually two flue gas outlets and four ESP inlets.The uniformity of the flue gas distribution and minimization the flow resistance of flue gas in the upstream of ESP Dust are the key issues in flue gas duct design.Through numerical simulation,the characteristics of flue gas flow in y-shaped upstream of ESP duct are analyzed,and the optimization are proposed.It is found that the diverting position structure of the yshaped flue has great influence on the flow distribution.The resistance of the Z-shaped composition elbow is very high.The proper introduction of flue gas guide baffles can greatly improve the uniformity of the flue gas distribution into ESP dust,and reduce the flow resistance.