【摘要】 为了证实和完善极限粒度理论,制备了煤粒度毫米级至厘米级(>10 mm)的5种粒度煤样,利用H-Sorb 2600T高温高压气体吸附分析仪对不同粒度的煤样进行等温吸附-解吸实验,并采用动扩散系数模型计算了煤粒瓦斯解吸扩散系数,分析不同粒度煤的扩散系数变化特征。研究结果表明:粒度毫米级煤样单位瓦斯解吸量和瓦斯解吸率随粒度的增大呈现逐渐减小的趋势;粒度厘米级煤样单位瓦斯解吸量和瓦斯解吸率随粒度的增大降幅较小;煤粒度在毫米级范围内,初始有效扩散系数D0e和平均有效扩散系数Dae随粒度的增大快速下降;煤粒度为厘米级时,初始有效扩散系数D0e和平均有效扩散系数Dae随粒度的增大基本保持不变;极限粒度理论正确可靠,煤的极限粒度小于10 mm。更多还原

【Abstract】 In order to confirm and improve the theory of limit particle size,five coal samples with different particle sizes from millimeter to centimeter( > 10 mm) were prepared. The isothermal adsorption-desorption experiments of coal samples with different particle sizes were carried out by using the H-Sorb 2600 T high temperature and high pressure gas adsorption analyzer. The dynamic diffusion coefficient model was used to calculate the gas desorption and diffusion coefficients of coal particles,and the variation characteristics of diffusion coefficients of coal with different particle sizes were analyzed. The results showed that the unit gas desorption amount and gas desorption rate of millimeter-sized coal samples presented a gradually decreasing trend with the increase of particle size,while the unit gas desorption amount and gas desorption rate of centimetersized coal sample decreased slightly with the increase of particle size. The initial effective diffusion coefficient D0 eand average effective diffusion coefficient Daedecreased rapidly with the increase of coal particle size in the millimeter range. When the particle size was centimeter,the initial effective diffusion coefficient D0 eand average effective diffusion coefficient Daebasically remained unchanged with the increase of particle size. The theory of limit particle size was correct and reliable,and the limit particle size of coal was less than 10 mm.更多还原