湿式电除尘器运行阻力问题的诊断与分析

Diagnosis and analysis of operating resistance of wet electrostatic precipitator

湿式电除尘器对酸雾、重金属以及PM 2.5微细粉尘有良好的脱除效果,可实现超低排放。在实际运行中,部分湿式电除尘器出现阻力偏高的现象。某火电厂2×393 MW机组配套的湿式电除尘器投运后,现场反馈阻力过大,影响系统安全稳定运行。为了验证湿式除尘器阻力大小及查找阻力过大原因,采用CFD模拟与物模试验相结合的方法,对湿式电除尘器的分段阻力进行研究,并将CFD模拟、物模试验结果与现场测试结果进行对比,最终确定湿式除尘器阻力分布异常区域为湿式电除尘器出口喇叭,主要是槽型板的阻力过大,建议取消槽型板。该研究为湿式电除尘器的改造提供参考依据。

The wet electrostaic precipitator has a good effect of removing acid mist,heavy metals and PM 2.5 fine dust,and can achieve ultra-low emissions.In actual operation,some wet electrostatic precipitators have a phenomenon of high resistance.After the operating of the wet electrostatic precipitator for a 2×393 MW unit of a thermal power plant,the on-site feedback resistance is too large,which affects the safe and stable operation of the system.In order to verify the resistance of the wet resistance and find out the cause for the excessive resistance,the method of combining CFD simulation and physical model is used to study the sectional resistance of the wet electrostatic precipitator.The results of CFD simulation and physical model were compared with on-site testing results.For comparison,it is finally determined that the abnormal area of the wet resistance distribution is the exit horn of the wet electrostatic precipitator,mainly because the resistance of the channel plates is too large,which provides a reference for the reform of the wet type electrostatic precipitator.