燃料分级与烟气再循环对天然气低氮燃烧特性影响机理  

Low NOx Combustion Mechanism of a Natural Gas Burner With Fuel-staged and Flue Gas Recirculation

作　　者：宋少鹏[1] 卓建坤[1] 李娜[1] 姚强[1] 焦伟红[2] 宋光武[2] 潘涛[2] SONG Shaopeng ZHUO Jiankun LI Nal YAO Qiang JIAO Weihong SONG Guangwu PAN Zao(Key Laboratory for Thermal Science and Power Engineering of Ministry of Education,Tsinghua University, Haidian Dstrict, Beijing 100084, China Beijing Municipal Research Institute of Environmental Protection, Xicheng District, Beijing 100037,China)

机构地区：[1]清华大学热科学与动力工程教育部重点实验室,北京市海淀区100084 [2]北京市环境保护科学研究院,北京市西城区100037

出　　处：《中国电机工程学报》2016年第24期6849-6858,共10页Proceedings of the CSEE

基　　金：国家自然科学基金项目(51576111);北京市科技计划课题(D141100001114001)~~

摘　　要：随着天然气工业锅炉污染物排放标准越来越严格,采用单一的氮氧化物控制技术手段难以满足现有需求。本文以NO_x排放低于30mg/m^3为目标,基于低氮燃烧器和外部烟气再循环的组合技术路线,设计开发了一种燃料分级低氮燃烧器,并在1.4MWth中试规模的燃气锅炉上,研究了燃料分级、化学当量比以及烟气再循环率等参数对燃烧特性以及NO_x生成的影响。结果表明:二次燃料比例、过量空气系数和烟气再循环率对燃烧稳定性、燃尽率和NO_x的生成具有重要影响;10%的烟气再循环率可以减少65%的氮氧化物排放;烟气再循环与二次燃料比例共同作用下,存着扇形火焰稳定燃烧区域。With the more stringent NOx emission limit from natural gas fired boiler, the natural gas burner with only one type of low NOx combustion technologies cannot meet the emission requirement of new-issued standard in Beijing. Thus a new fuel-staged low NOx bumer was developed with the help of the external flue gas recirculation （FGR）, where the NOx emission goal is below 30 mg/m3. And an experiment was carried out on the 1.4MWth pil0t-scale boiler, and the effects of staged fuel, ratio of flue gas recirculation and excess air on the combustion characteristics and NOx formation were extensively studied. The results shows that there is an important effect of secondary fuel ratio, excess air and the ratio of flue gas recirculation on the flame stability, and the formation of NOx. When the ratio of flue gas recirculation increases to 10%, 60% of NOx emission will be cut down. A fan-shaped stable flame area can be obtained by the effect of ratio of the ratio of FGR and secondary fuel stream.

关 键 词：天然气 低氮燃烧器 燃料分级 烟气再循环 燃烧稳定性 

分 类 号：TK223[动力工程及工程热物理—动力机械及工程]