油页岩颗粒燃烧的高温段多相燃烧模型

油页岩的燃烧过程是复杂的.基于热重燃烧曲线,可将油页岩的燃烧过程分为低温阶段、过渡阶段和高温阶段3部分:低温阶段为均相燃烧,高温阶段为多相燃烧,而过渡阶段则为高温阶段的多相燃烧准备条件.本文建立了高温段的多相燃烧模型:在能量方程中耦合了颗粒与外界环境之间的对流和辐射换热;低温阶段挥发分的大量释放使得油页岩内部孔隙增大,因而考虑了颗粒内表面积对碳的燃烧反应速率的影响;同时也考虑了挥发分和固定碳的燃烧对油页岩固体颗粒密度的影响.模型的计算结果与实验数据相吻合.

Heterogeneous combustion model for the high-temperature stage of oil shale particle combustion

Combustion process of oil shale is complex.Based on thermogravimetric combustion curves,the whole combustion process of oil shale is divided into three steps: low-temperature stage with homogeneous combustion,high-temperature stage with heterogeneous combustion,and transitional combustion stage preparing for the heterogeneous combustion.A new mathematical model is developed for the heterogeneous combustion: convective and radiative heat transfer between particle and ambient are included in energy equation;the effect of inner surface area on combustion reaction rate is considered;the influence of volatile and fixed carbon combustion on particle density has been considered in the model as well.At last,the model is validated by thermogravimetric experimental data.