多组分气体混合物在煤的孔隙中运动特性研究

Study on transport characteristics of multi-component gaseous mixtures through coal pore

煤的孔隙结构为气体的贮存和运动提供了良好的场所,煤自热过程中释放的气体混合物能在其孔隙中运动,也能受到煤的吸附作用。为了准确评估煤矿内源火灾风险,对瓦斯在煤颗粒孔隙中的运动特性进行了研究。研究了煤自热过程中释放的多组分气体,及其在煤颗粒的孔隙中运行特性。研究结果表明:煤的自热试验中反应器的出口处各种气体浓度可确定煤的自热释放特性,主要释放出气态氧化物(CO和CO_2)和热分解气体(烃类及H_2);这些气体的混合物可被用于煤矿内源火灾的风险评估;混合气体在煤中的吸附特性可由吸附柱的出口及入口气体浓度的比值确定。各组分气体在吸附柱的出入口浓度与各种气体分子的物理化学性质有关,临界温度较低的气体不容易在煤的孔隙中被吸附,分子尺寸小的气体比大分子气体更容易被吸附。

The study of gas movement in coal pore is of great significance to the accurate assessment of internal fire risk.The pore structure of coal provides a suitable medium for gas storage and movement.The gas mixture of gases released from the coal self-heating can move into the coal pore and be adsorbed by coal.In the paper,the activities of multi-component gases released from coal self-heating in the pore of coal particles are experimentally studied.The results show that the concentrations of various gases at the outlet of the reactor in the coal self-heating experiment determine the characteristics of coal self-heating.The main components of the released gaseous mixtures are gaseous oxides(CO and CO2)and pyrolytic gases(hydrocarbons and H2).These gas mixtures can be used for risk assessment of endogenous fire in coal mine.The results also demonstrate that the adsorption characteristics of mixed gases in coal can be determined by the ratio of gas concentration at the outlet to gas concentration at the inlet of the adsorption column.The concentration of each component gas at the inlet and outlet is related to the physical and chemical properties of gas molecules.Gases with lower critical temperature are not easily adsorbed in coal pore and gases with smaller molecular sizes are more easily adsorbed than those with larger molecular sizes.