大型燃煤电厂锅炉运行现状分析

Analysis of present operating situation of large size coal-fired utility boilers

我国大型电厂锅炉迅速发展,其可靠性和经济性都达到了较好的水平。按不同煤种分析现有各类锅炉的运行状况,切圆燃烧锅炉曾相当突出的炉膛出口烟气能量不平衡问题巳基本解决,且NOx的排放体积质量相对较低;墙式燃烧锅炉的NOx排放较高,并有一些锅炉存在炉内结渣等问题;低挥发分煤锅炉运行的可靠性、经济性和NOx排放问题较突出。在锅炉的选型设计中,选用较低的炉膛容积热负荷和较高的火焰高度是适宜的,磨煤机的选型也必须留有足够的余量。

Large size utility boilers develop rapidly in China,both their reliability and economics have reached better level.This paper analyzes the operating situations of various existing boilers on the basis of different coals,holds that,the notable energy imbalance problem of flue gas at the exit of furnace,ever existing in the tangential firing boilers has been basically solved,with comparatively lower emission concentration of NOx gained;the NOx of wall firing boiler is higher and furnace slagging etc.problems exist in some boilers;the operation reliability,economics and NOx emission etc.problems of low volatile coal-fired boilers are more notable.The comprehensive analysis shows that,it is appropriate to choose lower furnace volume heat release rate and higher flame height in the type selection design of blilers,and sufficient margin should be kept in the type selection of coal pulverizing mills.