急倾斜煤层地下气化数学模型的研究

STUDY ON MATHEMATICAL MODEL OF UNDERGROUND COAL GASIFICATION IN STEEP SEAM

煤炭地下气化产气过程与气化炉体的温度分布和渗流条件密切相关。根据急倾斜煤层赋存条件和气化过程的特点,建立了急倾斜煤层地下气化数学模型。介绍了模型参数的确定方法,采用控制容积方法对模型进行了求解,并在模型实验的基础上,对计算结果进行了分析。从温度场分布来看,计算值略高于实测值,各测点相对误差基本均在10%以内。根据模拟计算结果,随着气化通道长度增加,煤气热值提高,但在还原区以后,提高的幅度减小,温度场对煤气热值产生显著影响。由于受温度的影响,在高温区,煤气组分浓度场实测值的变化梯度大于计算值。结果表明,模拟值与实验值能够较好地相吻合,说明对急倾斜煤层地下气化温度场和浓度场的数值模拟是合理的。

The gas production process in underground coal gasification is closely related to the temperature distribution in gasification oven and seepage conditions A mathematical model on underground gasificaton in steep coal seam is established, according to its storage conditions and the feafures of gas production process The paper also introduces the methods of how to determine the main model parameters, and gets the model values by means of the control volume method, and gives an analysis of the calculation results on the basis of model experiment From the distribution of temperature field, the calculation values are slightly higher than the real measurement ones The relative differentiations of all measuring points are by and large within 10% According to the simulated calculation results, with the increase of the length of the gasification channel, the heating value of the gas increases However, after the reduction zone, it increases with a smaller margin The temperature field exerts noticeable effects on the heating value of the gas Due to the effect of temperature, in high temperature zone, the change gradient of the measured values of the concentration field of the gas compositions is larger than that of calculated ones On the whole the simulated values are identical with the test ones,which manifests the numerical simulation on the temperature field and concentration field in steep seam is right