煤吸附瓦斯影响因素的正交设计实验研究

Experimental study on influence factors of coal gas adsorption by orthogonal design

为研究含水率、粒径、温度等因素对煤样吸附瓦斯特性的影响,选取黄陵二号煤矿2~#煤层煤样,通过HCA型高压瓦斯吸附仪,采用正交实验法开展不同含水率、粒径、温度作用下煤样瓦斯等温吸附实验,得到了影响瓦斯吸附性能的主控因素。研究结果表明:不同含水率、粒径、温度条件下,煤的瓦斯吸附曲线均符合Langmuir理论;各因素对吸附常数a值的敏感性依次为粒径>温度>含水率,粒径影响程度是含水率的3.126倍、温度的4.458倍;各因素对吸附常数b值、吸附饱和度X值的敏感性依次为温度>粒径>含水率,温度对吸附常数b值的影响程度是粒径的3.946倍、含水率的7.719倍,温度对吸附饱和度X值的影响程度是含水率的4.947倍、粒径的1.918倍;煤样优先吸附水分,瓦斯吸附量随含水率的增大而减小;瓦斯吸附过程会放热,当温度升高时,瓦斯吸附量会减少;粒径减小,增大了煤样的比表面积,导致瓦斯吸附量增加。

In order to study the influence of moisture content, particle size, temperature and other factors on the gas adsorption characteristics of coal samples, the coal samples of No.2 coal seam of Huangling No.2 Coal Mine were selected. Through the HCA type high pressure gas adsorption device, the isothermal adsorption experiments of coal gas under different water content, particle size and temperature were carried out by orthogonal experiment method, and the main control factors influencing the performances of gas adsorption were obtained. The results show that the adsorption curves of coal to gas accord with Langmuir theory under different moisture content, particle size and temperature;the sensitivity of each factor to the adsorption constant a value is in the order of particle size > temperature > moisture content, the influence degree of particle size is 3.126 times of water content and 4.458 times of temperature;the sensitivity of each factor to the adsorption constant b value and adsorption saturation X value is in the order of temperature > particle size > moisture content. The influence degree of temperature on adsorption constant b value is 3.946 times of particle size and 7.719 times of moisture content. The influence degree of temperature on adsorption saturation X value is 4.947 times of moisture content and 1.918 times of particle size. The coal preferentially absorbs water, and the gas adsorption capacity decreases with the increase of moisture content. The gas adsorption process is exothermic, and when the temperature increases, the gas adsorption capacity decreases;the particle size decreases, and the specific surface area of the coal sample increases, so the gas adsorption capacity increases.