摘要
针对现有焦炉煤气石灰回转窑运行过程中热力型NO_(x)生成量偏高的问题,采用数值模拟的方法分别研究了空气助燃条件下一次风和二次风烟气再循环比例对窑内烟气温度分布以及NO_(x)生成量的影响。结果表明,两种烟气再循环方式均会降低烟气平均温度峰值与NO_(x)生成量,但也会减少石灰石在窑内的吸热量。一次风烟气再循环会加剧高温烟气向窑顶汇聚的问题,而二次风烟气再循环则能缓解该问题。当∅_(1)从0增加至1.0时,烟气平均温度峰值降低49.9 K,NO_(x)生成量减少62.5%,窑顶烟气最高温度增加23.1 K,窑底烟气最高温度降低63.7 K;当∅_(2)从0增加至0.2时,烟气平均温度峰值降低42.6 K,NO_(x)生成量减少65.7%,窑顶和窑底烟气最高温度分别降低37.6和14.6 K。
The lime rotary kiln using coke oven gas as fuel was generated a large amount of thermal NO_(x) in production.The influences of the primary air and the secondary air FGR ratio on flue gas temperature distribution and NO_(x) generation in kiln with air as oxidizer were studied by numerical simulation method.The results showed that both FGR methods reduced the peak of flue gas average temperature and the amount of NO_(x) generated,but they also decreased the heat absorption of limestone in the kiln.Among them,the primary air FGR exacerbated the convergence of high temperature flue gas to the kiln top,but the secondary air FGR suppressed it.When∅_(1) increased from 0 to 1.0,the peak of flue gas average temperature was reduced by 49.9 K,NO_(x) generation was decreased by 62.5%,the maximum flue gas temperature of kiln top was increased by 23.1 K,and the maximum flue gas temperature of kiln bottom was dropped 63.7 K.When∅_(2) increased from 0 to 0.2,the peak of flue gas average temperature was reduced by 42.6 K,NO_(x) generation was decreased by 65.7%,the maximum temperature of flue gas at the kiln top and the kiln bottom was dropped 37.6 and 14.6 K respectively.
作者
张玉
张林进
黄新景
Zhang Yu;Zhang Linjin;Huang Xinjing(Sinocalci Corporation)
出处
《冶金能源》
北大核心
2024年第5期28-32,共5页
Energy For Metallurgical Industry
关键词
石灰回转窑
数值模拟
烟气再循环
温度
NO_(x)
lime rotary kiln
numerical simulation
flue gas recirculation
temperature NO_(x)
