燃煤电厂超低排放改造后电除尘器效率降低的原因分析及控制对策

Reason Analysis and Countermeasures for Efficiency Reduction of Electrostatic Precipitator after Ultra-low Emission Transformation in Coal-fired Power Plants

燃煤电厂经过超低排放改造后,烟气污染物排放浓度大幅降低,脱硫、脱硝、电除尘器等烟气净化设备运行压力增加,一些电厂电除尘器出现二次电流提升困难、反复波动等现象,影响除尘效率。停机检查后发现极线、极板积灰严重,导致电晕线肥大,影响放电效果。极线、极板积灰严重时,会使极间距减小,产生电火花,造成二次电流不规则摆动。结合脱硝系统问题,提出运行过程中降低烟气中氨逃逸浓度和硫酸氢铵浓度的措施和建议。

After the ultra-low emission transformation in coal-fired power plants,the emission concentration of flue gas pollutants has been greatly reduced,and the operating pressure of flue gas purification equipment such as desulfurization,denitration and electric precipitator has been increased.In some power plants,the electric precipitator has encountered difficulties in raising the secondary current and repeated fluctuations,which affect the dust removal efficiency.After the shutdown inspection,it was found that the electrode line and plate accumulated serious ash,which led to corona line hypertrophy and affected the corona discharge effect.When the electrode line and the plate accumulate ash seriously,the distance between the poles will be reduced,and electric sparks will be generated,resulting in irregular swing of the secondary current.Combined with the problem of denitration system,measures and suggestions to reduce ammonia escape concentration and ammonium bisulfate concentration in flue gas during operation were put forward.