以某电厂220 MW机组燃煤锅炉湿式电除尘器为对象,运用计算流体动力学(CFD)数值模拟的方法,研究了湿式电除尘器4个电场的烟气流量和除尘效率分布特性,重点分析了粉尘颗粒在湿式电除尘器电场和出口烟道内部的分布情况.结果表明:烟气流量分配不均会导致电场除尘效率存在差异,电场烟气量越大,除尘效率越低;导流板不能同时有效调节烟气和粉尘颗粒的流动特性;粉尘颗粒质量浓度在湿式电除尘器出口烟道内分布不均,会导致粉尘排放连续监测系统数据失真;采用多点测量取平均值的方法可得到真实的湿式电除尘器粉尘颗粒排放情况.%Taking the wet electrostatic precipitator in a 220 MW unit coal-fired boiler as the research object, the computational fluid dynamics (CFD) numerical simulation method was applied to study the flue gas flow and dust removal efficiency distribution of four electric fields in the wet electrostatic precipitator. The distribution of dust particles in the electric fields and outlet duct was analyzed emphatically. The results show that, uneven distribution of the flue gas flow causes deviations of dust removal efficiency in the electric fields. The larger the flue gas flow of the electric field, the lower the dust removal efficiency of the electric field. The baffle cannot regulate the flow characteristics of the flue gas and dust particles simultaneously. The mass concentration of dust particles in the outlet duct has an uneven distribution, which results in data distortion of the continuous emission monitoring system (CEMS). Taking the average of multi-point measurement results can assess the dust particles emissions from the wet electrostatic precipitator effectively.
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