水蒸气对煤粉在滴管炉富氧燃烧条件下着火的影响

摘要

通过实验和数值模拟研究了体积分数5%,、10%,、20%,和30%,的水蒸气替代CO2在氧气体积分数为21%,、30%,和40%,工况下,水蒸气对煤粉在O2/CO2/H2O气氛中着火的影响.实验结果表明,体积分数5%,、10%,和20%,的水蒸气添加到O2/CO2气氛中,其着火点位置没有明显区别.当水蒸气体积分数增加到30%,时,着火点距离显著减小,着火提前.通过拟建的CFD模型计算得出H2O的化学属性导致了着火提前,而物理属性导致了着火延迟,在高体积分数水蒸气条件下其化学属性的影响大于物理属性的影响,最终导致了着火大幅提前.%The substitution of CO2 by 5%,10%,20%, and 30%, steam was implemented to evaluate the effect of the mole fractions of steam on the ignition of coal in O2/CO2/H2O atmospheres with the oxygen mole fractions of 21%,30%, and 40%, by using experimental and numerical methods.The experimental results reveal that the igni-tion distances are barely affected when the low mole fraction of steam(5%,10%, and 20%,)was added to O2/CO2 atmospheres.As the mole fraction of steam was increased to 30%,the ignition distance was significantly de-creased.The numerical results indicate that the physical properties of steam lead to the ignition delay of coal while its chemical properties are beneficial to the ignition.