超超临界锅炉排烟温度高的原因分析及处理

Cause Analysis and Treatment of High Temperature of Exhaust Gas in Ultra Supercritical Boiler

在火力发电厂中,排烟温度是锅炉机组重要经济运行指标之一,排烟热损失是锅炉各项热损失中最大的一项,对机组运行经济性影响较大。在就某发电公司660 MW超超临界锅炉排烟温度偏高的原因进行了分析和诊断后,找出关键影响因素,通过优化燃烧调整,并对一次风压、磨煤机一次风速、磨煤机入口一次风量和锅炉氧量重新标定,优化制粉系统运行方式,提高磨煤机出口温度,降低空气预热器疏导风机频率,将锅炉燃烧工况调整到最优,锅炉排烟温度由2015年的121.95℃将至目前的115.55℃。基本解决了该机组投产后锅炉排烟温度高的问题。

In the thermal power plant, the flue gas temperature is one of the important economic indicators of boiler, the heat loss of exhaust gas, the largest one in the boiler heat loss, has a great impact on the economic operation of the unit.This paper analyzes high temperature of exhaust gas in a power company 660 MW ultra supercritical boiler and finds out the key factor,through adjusting the primary air pressure, primary air velocity and primary air flow in entrance of pulverizer, boiler oxygen,optimizing the operation mode of pulverizing system, raising the mill outlet temperature, reducing the air preheater fan frequency, the combustion condition can be adjusted to the best. The temperature of exhaust gas is reduced from 121.95 ℃ in2015 to the current 115.55 ℃, the problem of high temperature of exhaust gas of boiler since the unit has been put into operation is basically solved.