The lime rotary kiln using coke oven gas as fuel was generated a large amount of thermal NOx in production.The influences of the primary air and the secondary air FGR ratio on flue gas tem-perature distribution and NOx generation in kiln with air as oxidizer were studied by numerical simula-tion method.The results showed that both FGR methods reduced the peak of flue gas average tempera-ture and the amount of NOx 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.Whenϕ1 increased from 0 to 1.0,the peak of flue gas average temperature was reduced by 49.9 K,NOx 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 temper-ature of kiln bottom was dropped 63.7 K.Whenϕ2 increased from 0 to 0.2,the peak of flue gas aver-age temperature was reduced by 42.6 K,NOx generation was decreased by 65.7%,the maximum tem-perature of flue gas at the kiln top and the kiln bottom was dropped 37.6 and 14.6 K respectively.
lime rotary kilnnumerical simulationflue gas recirculationtemperatureNOx
维普
万方数据
