常用经验模型预测煤屑瓦斯解吸量对比分析

Comparative analysis on gas desorption prediction of coal cuttings based on common empirical models

为研究常用瓦斯解吸经验模型对解吸量预测准确性,基于容量法试验测定长时间的煤屑瓦斯累计解吸量,通过截取不同时段的瓦斯解吸量数据回归拟合得到常用解吸经验模型参数,并将其代入模型中计算出瓦斯解吸量与试验测定量进行对比。研究结果表明:各常用经验模型公式对不同时间段数据拟合都表现出较好的效果;巴雷尔式不适合用于煤屑的瓦斯解吸预测;指数型经验模型公式计算得到曲线受制于拟合数据时间段长短,在拟合时间段后很快趋于平直而低估累计瓦斯解吸量;乌斯季诺夫式适合用于短时间煤屑瓦斯解吸数据推算长期瓦斯解吸量;重庆-文特式适合用于预测短期瓦斯解吸量,而利用较长时间段瓦斯解吸量数据推算煤屑瓦斯解吸量宜采用艾黎式。该研究成果对于煤的瓦斯涌出及煤层气产能预测有着重要实际意义。

In order to study the accuracy of common empirical models for the gas desorption prediction,the cumulative amount of gas desorption of coal cuttings for a long time was measured based on the volumetric method test.The parameters of the common empirical models were obtained by regression fitting on the data of gas desorption intercepted in different time periods,and they were substituted into the models to calculate the gas desorption amount,which were compared with the experimental measured data.The results showed that the formulas of common empirical models presented good effect for data fitting in different time periods.The Barrer formula was not suitable for predicting gas desorption of coal cuttings.The curves calculated by the empirical model formula of exponential type were restrained by time length of fitting data,and tended to be flat quickly after the fitting time period,so the cumulative amount of gas desorption was underestimated.The Ustinov formula was suitable for calculating the long-term gas desorption amount by using the short-term gas desorption data of coal cuttings,and the Chongqing-Venter formula was suitable for predicting the short-term gas desorption amount,while the Airey formula was good at calculating the gas desorption amount of coal cuttings by using the data of gas desorption amount in a relative long time period.The research results have important practical significance for predicting the coal gas emission and CBM productivity.