煤粒瓦斯初始扩散系数及其影响因素

Gas Initial Diffusion Coefficient and Its Influencing Factors in Coal Particle

通过扩散实验对平煤八矿、鹤壁六矿原生结构煤/构造煤煤样进行研究分析,利用实验数据,并结合动扩散系数新模型,分别计算出0.5、1.0、1.5 MPa 3个吸附平衡压力下的初始扩散系数D_0,经过比较分析,初步探讨了不同煤体结构、不同变质程度、不同粒径在不同吸附平衡压力下对煤样的D_0的影响规律：整体上来看,构造煤初始扩散系数D_0比原生结构煤要大;在构造煤的对比中,鹤壁贫瘦煤煤样的初始扩散系数小于平顶山肥煤煤样的初始扩散系数,而在原生结构煤的对比中,扩散系数的大小关系整体上呈现相反的规律;随着压力的变化,构造煤粒径为0.5~1.0 mm的煤样的初始扩散系数D_0明显大于粒径为0.25~0.5 mm的煤样,原生结构煤2种粒径煤样的D_0大小对比结果整体上呈现出相似规律。

Based on the study and analysis of the undeformed/deformed coal samples from No. 8 Mine of Pingdingshan and No. 6 Mine of Hebi by diffusion experiment,combined with the new model of the dynamic diffusion coefficient and using experimental data,the initial diffusion coefficients（ D_0） under three adsorption equilibrium pressure（ 0. 5 MPa,1. 0 MPa,1. 5 MPa） were calculated respectively,the influence of different coal structures,different metamorphic grades,different particle sizes on D_0 of coal samples under different adsorption equilibrium pressure is discussed preliminarily： on the whole,the initial diffusion coefficient D_0 of deformed coal is higher than that of undeformed coal; the initial diffusion coefficient of meager lean coal from Hebi is less than that of fat coal from Pingdingshan; with the change of pressure,for the deformed coal,the initial diffusion coefficient of coal sample with the size of 0. 5 mm to1. 0 mm is obviously higher than that of 0. 25 mm to 0. 5 mm; there is similar rule to follow of two kinds of D_0 with different particle sizes for the undeformed coal.