燃烧初期化学当量比对锅炉NO_x生成与排放特性的影响  

Influence of Stoichiometric Ratio at Initial Combustion Stage on NO_x Formation and Emission Characteristics of a Utility Boiler

作　　者：赵斯楠 方庆艳[1] 马仑[1] 陈刚[1] 

机构地区：[1]华中科技大学煤燃烧国家重点实验室,武汉430074

出　　处：《燃烧科学与技术》2017年第3期236-241,共6页Journal of Combustion Science and Technology

基　　金：华中科技大学校青年基金资助项目(01-18-120070)

摘　　要：采用数值模拟方法,研究了燃烧初期化学当量比对一台1,000,MW超超临界塔式锅炉在中低负荷下NO_x生成与排放特性的影响.计算值与试验测量值符合较好.结果表明,中低负荷下煤粉燃烧初期化学当量比下降,热力型NO_x与燃料型NO_x生成速率均明显降低,且已生成的NO_x被还原的速率增加,NO_x排放也随之降低.现场试验中,通过关小周界风挡板开度降低燃烧初期化学当量比,锅炉在700,MW和500,MW负荷下NO_x排放分别下降了20.6%,和28.2%,,且不会对锅炉效率及蒸汽参数等产生负面影响.Numerical simulations were conducted to investigate the influence of stoichiometric ratio at initial com-bustion stage on NOx formation and emission characteristics of a 1,000,MW ultra-supercritical tower boiler. The calculated values are highly consistent with the measured values. The results indicate that with decreasing stoichiometric ratio at initial combustion stage at medium-low loads, the formation rates of thermal NOx and fuel NOx greatly decrease, and the reduction rate of generated NOx increases, eventually leading to the decrease of NOx emissions. In field trials, fuel-air damper opening was reduced to decrease the stoichiometric ratio at initial combus-tion stage. The NOx emissions decrease by 20.6%, at 700,MW and by 28.2%, at 500,MW without negative effects on boiler efficiency and steam temperature.

关 键 词：塔式锅炉 NOX排放 化学当量比 数值模拟 

分 类 号：TK227[动力工程及工程热物理—动力机械及工程]