超低排放风烟系统的技术问题和对策

Technical Problems and Countermeasures From the Gas System of the Ultra-low Emission Project

超低排放环保示范工程改造,在取得优异的超低排放成绩的同时,碰到了来自风烟系统的比较棘手的问题。阻力增加、体积流量减少的双重因素使引风机的运行点向不稳定区域移动从而造成风机在低负荷工况失速,导致引风机的"抢风"运行,使系统出现压力过高、膨胀节泄漏、进口挡板偏移、无法投入自动运行等问题。本文从引风机的性能曲线、状态点的分析出发,提出解决问题的6种方法,而采用了其中更换风机叶轮的方法。通过与历史数据的对比,提出了解决问题采取的临时措施。

The demonstration project transformation with ultra-low emission for environmental protection,which gets the excellent achievement,comes across a series of puzzling problems from the gas system. Because of double factors of resistance increase and volume flow rate decrease,the running state points of two induced draft fans move toward the unstable region,causing fan stalls on the low load conditions. Scrambling for air of induced draft fans come cross problems,such as high gas pressure,crack and leakage of bellows expansion joints,inlet baffle migration,and non-automatic operation.Based on analysis of operating points and characteristic curves of induced draft fans,this paper puts forward six solutions,among which replacement of fan impeller is used. By comparison and analysis between historical and present data,provisional measures for solving the problems are put forward.