煤炭地下气化技术进展与工程科技

Progress and technology of underground coal gasification

介绍了国内外煤炭地下气化的研究历程,总结了煤炭地下气化的技术特点及研究成果,并指出了其工程科技问题及应用前景。结果表明,在100多年的开发研究过程中,形成了3种类型的煤炭地下气化技术:①长壁式气流法气化技术,进气点和出气点固定,分别位于气化通道的两端,一个井进气,另一个井出气,利用气流流动速度控制气化工作面的移动;②渗透式气化技术,利用煤层自然裂隙或人造裂隙作为气化通道;③控制后退注气点气化技术,在气化通道中设置注气管,利用注气管连续或间断后撤,实现注气点连续或间断后退移动。国内外煤炭地下气化技术还没有实现大规模产业化,需要进一步加强基础研究和工程技术开发,基础研究包括地质评价,实体煤层燃烧、热解、气化、贯通特性及气化过程特征场的演化规律,煤层上覆岩在高温作用下的热物性变化及冒落规律,地下煤气化污染物在燃空区的富集、迁移规律;工程技术开发包括规模化生产地下气化炉结构及构建技术,地下气化连续稳定控制技术,注气点移动控制装备,煤炭地下气化安全技术,污染物监控及燃空区管理技术,低成本的火区探测及气化过程分析技术,煤炭地下气化多联产技术。煤炭地下气化技术可以回收老矿井遗弃煤炭资源和开采深部煤炭资源,对保障我国能源安全具有重要的战略意义。

The research history of underground coal gasification(UCG)at home and abroad is introduced.The characteristics and research results of UCG technology are summarized.The technological problems and application prospects are presented.The results show that during more than 100 years’development and research,three types of UCG technologies have been developed including:①Long-wall airflow gasification technology,which the inlet and outlet points are fixed,locating at both ends of the gasification channel,one well for air inlet and the other well for gas outlet.The airflow velocity is used to control the movement of the gasification working surface.②Osmotic gasification technology,which uses natural or artificial fissures in the coal seam as the gasification channel.③Controlled retraction injection point(CRIP)gasification technology,which the injection air pipe is set in the gasification channel,and continuous or intermittent retracement of injection pipe is used to realize the continuous or intermittent backward movement of the injection air point.However,the UCG technology has not yet achieved large-scale industrialization,and it is necessary to further strengthen basic research and technological development.The basic researches should include geological evaluation,combustion,pyrolysis,gasification,the penetration characteristics of solid coal seams and evolution of characteristic fields in gasification process,the thermal properties change and caving of coal seam overlying rock mass under high temperature,and the enrichment and migration law of UCG pollutants in the cavity.The technologies should include the underground gasifier structure and construction of large-scale production,the continuous stability control of UCG,the control equipment of injection air point movement,UCG safety,pollutant monitoring,cavity management,low-cost fire area detection and gasification process analysis,and UCG multi-production.UCG technology can recover abandoning coal resources in old coal mines and exploit deep coal resources,which is of great strategic significance for ensuring energy security.