国华太仓发电有限公司2×600MW机组空气预热器对SCR系统的适应性改造

The Adaptability Retrofit for Adding SCR 2×600 MW Boilers in Guohua Taicang Power Plant

介绍了针对600 MW锅炉机组加装SCR系统的空气预热器改造过程,提供了改造前后的空气预热器对比性能参数,对改造过程中所遇到的问题进行了分析并提出了解决方案。通过改造发现,加装SCR会导致空气预热器入口烟气温度下降,影响空气预热器的换热量。空气预热器通过增加部分换热面能改善空气预热器的换热情况。对氨气逃逸率控制良好的锅炉,空气预热器堵灰程度和阻力上升均很轻微。对磨煤机进口要求温度较高的运行情况,改变空气预热器的转向为先加热一次风,能明显提高一次风出口温度,保证制粉系统在锅炉低负荷时的灵活条件需要。

This article introduced the air heater retrofit sample for fitting the boiler adding the SCR system in a 2 × 600 MW plant, supplied the air heater operation performance data before and after retrofit. The analysis on the problem happened during the retrofit process and the solving suggestion are given. The retrofitting process shows, after boiler adding SCR device, the air preheater inlet gas temperature dropped lead to the preheater heat exchange quantity decreased. Adding the preheater heat exchange surface can improve this situation. To ammonia slip best controlled boiler the preheater retrofit only adding limited fouling and gas gressure drop in air preheater. To needing hagher mill inlet temperature design case, change the preheater rotation direction to heating primary air first can increase the mill inlet temperature obviously, and this point can guarantee the coal powder making system adjusting performance flexibly, especially at the lower boiler load condition.