两阶段煤炭地下气化温度场模型

引　言煤炭地下气化过程实际上是一个自热平衡过程 ,依靠煤燃烧产生的热量使地下气化炉内建立起理想的温度场 ,进而发生还原反应和分解反应 ,产出煤气 .因此 ,在地下气化过程中起关键作用的是炉内的温度场 ,尤其对于两阶段地下气化更是如此 .两阶段气化是一种循环供给空气和水蒸气的地下气化方法 ,每个循环由两个阶段组成 :第 1阶段为鼓空气燃烧蓄热 ,生产空气煤气 ;第 2阶段为鼓水蒸气生产地下水煤气 .只有在第 1阶段积蓄了足够量的热能以后 ,才能使第 2阶段水蒸气的分解反应得以顺利进行 ,从而产生高热值地下水煤气 ,同时煤层热分解的程度…

TEMPERATURE FIELD MODEL OF TWO-STAGE UNDERGROUND COAL GASIFICATION

Two-stage underground coal gasification is an effective method which can produce water gas with high heating value,while the temperature is the key factor that determines on its producing process. On the basis of model test, the mathematical model for two dimensions, non-linear, unsteady temperature field is established through analyzing the distribution law of temperature field for combustion and gasification of coal seam in the stove, and outlining and treating the boundary conditions. A selection method of the model parameters has been introduced. The mathematical model is solved by the control volume method,and calculation results are analysed. The uniformity of calculation and real measurement value indicate that the numerical simulation of dynamic state temperature field for the coal seam medium in the gasification stove is correct.Thereby,it provides a necessarily theoretical base for further quantitative study on process of underground coal gasification.