不同过氧系数下煤粉MILD-Oxyfuel燃烧的数值模拟  

Numerical Simulation on MILD-Oxyfuel Combustion of Pulverized Coal at Different Excess Oxygen Coefficients

作　　者：潘聪[1] 张立麒[1] 毛志慧[1] 郑楚光[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：《动力工程学报》2015年第12期956-963,共8页Journal of Chinese Society of Power Engineering

基　　金：国家重点基础研究发展计划资助项目(973计划)(2011CB707301);高等学校博士学科点专项科研基金资助项目(20130142130009)

摘　　要：对煤粉MILD-Oxyfuel燃烧进行了数值模拟,研究不同过氧系数对煤粉MILD-Oxyfuel燃烧的影响.以0.3MW竖直实验炉为研究对象,分别计算了煤粉MILD燃烧和MILD-Oxyfuel燃烧下过氧系数为1.20、1.15、1.10和1.05等8种工况,并以过氧系数为1.20的常规旋流燃烧作为参考工况,分析比较了9种工况下的炉膛温度分布以及CO和NO体积分数分布.结果表明:相同过氧系数时,MILD-Oxyfuel燃烧方式下的温度比MILD燃烧方式下低,温度分布更均匀;在相同燃烧方式下,过氧系数为1.20和1.15的工况下燃烧状况相似,过氧系数为1.10的工况下温度分布更均匀;MILD燃烧和MILD-Oxyfuel燃烧产生的NO体积分数比常规旋流燃烧降低了近40%,过氧系数对NO体积分数的影响不大.To study the effects of excess oxygen coefficient on the MILD-Oxyfuel combustion of pulverized coal,the MILD-Oxyfuel combustion process was numerically simulated.Taking a 0.3MW vertical furnace for pulverized coal combustion as an object of study,numerical calculations were carried out under 8cases respectively in the mode of MILD combustion and MILD-Oxyfuel combustion at excess oxygen coefficients of 1.20,1.15,1.10 and 1.05,etc.,with the conventional swirl combustion at excess oxygen coefficient of1.20 as the reference case.Meanwhile,the distribution of furnace temperature and volumetric concentration of CO and NO were analyzed and compared under 9cases.Results show that at the same excess oxygen coefficient,the temperature in MILD-Oxyfuel combustion mode is lower and more uniformly distributed than that in the mode of MILD combustion;whereas in the same combustion mode,the combustion status at excess oxygen coefficient of 1.20 is similar with that at excess oxygen coefficient of 1.15,and the temperature distribution is the most uniform at excess oxygen coefficient of 1.10.The volumetric concentration of NO is reduced by 40%in both the modes of MILD and MILD-Oxyfuel combustion,but the ex-cess oxygen coefficient affects little on the NO volumetric concentration.

关 键 词：MILD-Oxyfuel燃烧 过氧系数 NO 数值模拟 

分 类 号：TK227.1[动力工程及工程热物理—动力机械及工程]