China University of Mining and Technology( Beijing) ENN Gasification and Mining Company Limited

对煤炭地下气化反应过程的认识是制定稳定控制工艺的理论基础,与地面移动床气化相比,煤炭地下气化表现为煤层固定,而反应区移动,反应过程受限于气化通道两侧煤层的热剥落与热破碎,其实质为不同尺度煤块、煤层夹矸、顶板垮落岩石混杂的渗滤通道反应。煤炭地下气化的析气过程可分解为沿气化通道径向煤壁内的煤气析出过程、沿气化通道轴向的煤气化过程、通道有氧区可燃组分的二次燃烧以及气流通道中的水煤气变换反应4个过程。对于单个反应周期,随煤的消耗、气化通道的扩展,二次燃烧加剧,煤气质量下降,稳定周期结束。采用控制工艺,如注入点后退气化,可通过参数调节控制单个周期煤气组分的波动范围,并实现多个生产周期的接续,从而实现稳定生产。

To know clearly the reaction process of underground coal gasification was the theoretical base to set up the stable control technique. In comparison with the moving bed gasification,an expression of the underground coal gasification was a fixed seam,but the reaction area was in moving,the reaction process was limited by the h eat spalling and thermal fragmentation of the two side seams along the gasified channel. The essence was a percolation channel reaction with different size lump coal,sea m parting,roof falling rock mixed. With the analysis,the precipitation process of the underground coal gasification could explain gas precipitation process in the radial coal wall along the gasification channel,an axial gasification process along the gasification channel,secondary combustion of the combustible components in the aerobic area of the gasification channel and a water-gas exchanging reaction process in the air flow channel. As for a single reaction period,with the coal consumption,gasification channel expanded,secondary combustion enhanced and gas quality reduced,the stable period would be terminated. With an application of a control technique,such as the retreated gasification at an injection point,the parameters adjustment could be applied to control the fluctuation scope of single periodic gas components and could realize the conne ction of multi production periods in order to realize the stable production of the underground coal gasification.

国家自然科学基金资助项目(51476185)；中央高校科研业务专项基金资助项目(2009QH13)；国家高技术研究发展计划(863计划)资助项目(2011AA050101)；