变温变压下煤层气吸附量的预测

Prediction of adsorption capacity of coal bed methane under variable temperature and pressure

等温吸附虽然被大量学者进行研究并用于煤层气储量的预测,由于其实验条件不符合实际开采过程中的地温与地压,故很多专家提出用变温变压的实验条件来预测煤层气的吸附量,但是到目前为止鲜有很好的方程来处理变温变压实验数据。本文基于煤炭科学研究总院西安研究院张庆玲对4种不同煤级煤样在变温变压吸附实验的研究,提出了温度-压力-吸附量方程(TPAE方程)用于煤层气在温度和压力共同影响下吸附量的预测。通过TPAE方程,对4种不同煤级在变温变压下吸附量进行回归预测。结果表明:TPAE方程可以非常好地处理变温变压吸附实验数据,4种煤样的回归计算值与实测值最大平均相对误差为2.64%,最小为1.63%,同时实现温度和压力及吸附量三维视图的可视化,从图中可知任意温度和压力下煤层气的吸附量。

Although the isothermal adsorption is studied by a large number of scholars and used to predict the reserves of coal bed gas,because the experimental conditions are not compatible with the ground temperature and ground pressure in the actual mining process,many experts have proposed to use the experimental conditions of variable temperature and pressure to predict the adsorption capacity of coal bed gas,but at present,there is not a good equation to deal with the variation of temperature and pressure experimental data.Based on the study of four different coal rank samples in variable temperature and pressure adsorption experiments by Zhang Qingling,Xi’an Branch of China Coal Research Institute,a temperature-pressure-adsorption equation(TPAE equation)is proposed for predicting the adsorption capacity of coalbed methane under the comprehensive influence of temperature and pressure.The adsorption capacity of four different coal ranks under variable temperature and pressure was predicted by the TPAE equation.The results showed that TPAE equation can deal with experimental data of variable temperature and pressure adsorption,and the measured values of the maximum average relative error is 2.64% to the regression values of four coal samples,the minimum is 1.63%,at the meantime,the visualization of the three-dimensional view of temperature and pressure and the amount of adsorption is realized,and the adsorption amount of coal gas under any temperature and pressure is known from the diagram.