Fu Xiang, Liu Xuan, Wu Qixuan, Chang Teng, Wang Yifan
College of Mining, Liaoning Technical University, Fuxin 123000, China.
ACS Omega. 2024 Feb 16;9(8):9170-9184. doi: 10.1021/acsomega.3c08091. eCollection 2024 Feb 27.
In view of the current situation where most studies on gas desorption characteristics are limited to the atmospheric pressure desorption environment, we have independently developed a coal methane desorption instrument to test the nonatmospheric pressure desorption characteristics for coal particle gas beneath the condition of desorption damage. The instrument can arbitrarily adjust the gas pressure in the range of measurement while controlling the instantaneous release of excess gas to keep the desorption environment pressure constant. We measured the methane desorption amount of coal samples with different desorption times within 3 h and calculated the desorption velocity. The results show that the final desorption amount and desorption velocity of gas scale up with the increase of times, and the final desorption amount of coal sample W-01 increases the most, which is 18.5%. With the passage of time, the diffusion coefficient decreases gradually, and the number of desorption times is directly proportional to the diffusion coefficient. Its relative deviation of diffusion coefficient between different desorption times of the same coal sample can reach up to 40%, and the desorption time in the range of 5 to 30 min is the area with high relative deviation. A quantitative index of a double-parameter damage model based on desorption conditions and adsorption pressure is proposed, and the damage extent of each sample is evaluated. The damage quantitative index of coal sample W-01 is the highest, which is 0.87. The methane desorption model of coal under the condition of desorption damage is constructed, and more than 30 groups of experiments are verified.
鉴于目前大多数瓦斯解吸特性研究局限于常压解吸环境，我们自主研发了一套煤体瓦斯解吸仪，用于测试煤颗粒瓦斯在解吸损伤条件下的非常压解吸特性。该仪器在控制过量瓦斯瞬时释放以保持解吸环境压力恒定的同时，能在测量范围内任意调节瓦斯压力。我们测量了3小时内不同解吸时间的煤样甲烷解吸量，并计算了解吸速度。结果表明，瓦斯的最终解吸量和解吸速度随时间增加而增大，煤样W-01的最终解吸量增加最多，为18.5%。随着时间推移，扩散系数逐渐减小，解吸次数与扩散系数成正比。同一煤样不同解吸时间的扩散系数相对偏差可达40%，5至30分钟范围内的解吸时间是相对偏差较大的区域。提出了基于解吸条件和吸附压力的双参数损伤模型定量指标，并对各样本的损伤程度进行了评估。煤样W-01的损伤定量指标最高，为0.87。构建了解吸损伤条件下煤体甲烷解吸模型，并进行了30多组实验验证。
