千瓦级煤粉的预热燃烧负荷变化

Load variation of kilowatt-level preheating combustion for pulverized coal

依托千瓦级煤粉预热燃烧综合评价实验平台,研究低负荷预热燃烧特性和负荷变化的动态响应特性。结果表明:实验平台在负荷为设计功率的30%状况下运行时,预热温度达到900℃,且预热燃烧系统运行稳定,烟气中的CO排放质量浓度为25 mg/m^(3),NO_(x)排放质量浓度为150 mg/m^(3)。负荷由设计功率的30%升至42%时,预热温度变化速率为3.2℃/min,预热室升负荷速率为2.4%/min,卧式燃烧室温度变化速率为4.1℃/min,卧式燃烧室升负荷速率为1.3%/min;负荷升高过程中,预热煤气的CO_(2)体积分数先减小后增大,CO和H_(2)体积分数先减小后增大,CH_(4)体积分数基本不变;尾部烟气的CO质量浓度先增大后减小,NO_(x)质量浓度先减小后增大。

Based on the comprehensive evaluation experimental platform of kilowatt-level pulverized coal preheating combustion,this paper conducted experimental research on low-load preheating combustion characteristics and dynamic response characteristics of load changes.The results show that when the experimental platform runs under the load of 30%,the preheating temperature reaches 900℃,and the preheating combustion system works stably,the CO emission in the flue gas is 25 mg/m^(3),and the NO_(x) emission is 150 mg/m^(3).When the load increased from 30%to 42%,the preheating temperature change rate is 3.2℃/min,the load increasing rate of the preheating chamber is 2.4%/min,the temperature change rate of the horizontal combustion chamber is 4.1℃/min,and the load increasing rate of the horizontal combustion chamber is 1.3%/min.During the load increasing process,the CO_(2) content volume fraction of the preheating gas first decreases and then increases,the CO and H_(2) content volume fraction first decreases and then increases,and the CH_(4) content volume fraction remains basically unchanged.The mass concentration of CO content in the tail flue gas increases first and then decreases,and the mass concentration of NO_(x) first decreases and then increases.