褐煤锅炉中速磨煤机直吹式系统的二介质干燥方案及实现OA

The issue of drying capacity in medium-speed mill direct-fired pulverizing systems for lignite-fired boilers has long been a challenge for the power industry.A two-medium drying scheme using high-temperature flue gas combined with high-temperature hot air is proposed,and its engineering implementation has successfully resolved the problems of excessively high primary air flow and insufficient drying capacity when grinding high-moisture lignite in medium-speed mill direct-fired systems.Practical application in a 660 MW unit demonstrates that under various load conditions,this system thoroughly addresses the issues of low hot primary air temperature and insufficient mill drying capacity in lignite-fired boilers,raising the mill outlet temperature by 5-10 ℃.Moreover,the reduction in primary air flow and the introduction of flue gas into the primary air significantly lower NOx generation in the furnace,reduce the operating cost of the boiler SCR system,alleviate air preheater blockage caused by high ammonia slip,and decrease the induced draft fan current.The reduction in both primary air fan current and induced draft fan current also contributes to a lower auxiliary power consumption rate.