湿法烟气脱硫系统气-气换热器堵塞机理分析  

Analysis on Blockage Mechanism of Gas-Gas Heater in Wet Flue Gas Desulfurization Systems

作　　者：肖海平[1] 张千 孙保民[1] 

机构地区：[1]华北电力大学电站设备状态监测与控制教育部重点实验室,北京102206 [2]神华国华(北京)电力研究院有限公司,北京100069

出　　处：《动力工程学报》2011年第1期53-57,共5页Journal of Chinese Society of Power Engineering

基　　金：中央高校基本科研业务费专项资金资助项目(09ZG02)

摘　　要：研究了湿法烟气脱硫系统气-气换热器（GGH）堵塞的机理,用X射线衍射仪分析了GGH结垢物的物相组成,测量了脱硫系统除雾器入口烟气流速、出口烟气携带的小液滴浓度以及除雾器叶片的除雾效率.结果表明：垢的主要成分为石膏和CaSO4,飞灰参与了垢的形成过程;除雾器后净烟气携带的浆液粒径主要分布在10~30μm;随着气流速度的加快,除雾效率呈现先提高后降低的趋势;当烟气流速高于8 m/s后,除雾器出现严重的二次携带,除雾效率急剧下降;除雾器入口烟气流速分布不均,整体流速偏高,整体除雾效率为68.67%;净烟气从脱硫塔携带出的脱硫浆液是造成堵塞的主要物质,除雾器脱除效率偏低,使得小粒径的脱硫浆液流经除雾器进入GGH,造成堵塞.To study the blockage mechanism of gas-gas heater（GGH） in a wet flue gas desulfurization system,phase composition of scales on GGH was analyzed by X-ray diffraction,while velocity of demister inlet flue gas and concentration of droplet carried by the outlet flue gas measured as well as the demisting efficiency deduced.Results show that CaSO_4·2H_2O and CaSO_4 are the main components of the scale and the scaling process involves the fly ash.In the purified flue gas,the size distribution of droplet mainly lies in 10 to 30 μm.The demisting efficiency first increases and then decreases with rising gas velocity.When the gas velocity gets above 8 m/s,droplet reentrainment will occur,resulting in seriously lowered demisting efficiency.The overall demisting efficiency can reach only 68.67% due to poor distribution and high value of inlet gas velocity.The blockage of GGH mainly attributes to the low demisting efficiency,which allows the small droplets from desulfurization process into GGH.

关 键 词：湿法烟气脱硫 气-气换热器 除雾器 除雾效率 结垢 堵塞机理 

分 类 号：X701.3[环境科学与工程—环境工程]