损失瓦斯量与煤的破坏类型关系研究

Study on relationship between gas loss quantity and destruction types of coal

损失瓦斯量是准确获取煤层瓦斯含量的基础数据。通过实验室测定和不同损失量计算模型的对比分析,表明采用传统的t法和幂函数法获取损失瓦斯量时,Ⅱ类、Ⅲ类和Ⅳ类煤符合性较好,误差小于20%,I类煤和Ⅴ类煤的损失瓦斯量误差为25%~31%;煤中孔隙结构的差异是误差产生的原因,I类煤中原生孔隙占多数,Ⅴ类煤的孔隙受构造影响最大,其它类型煤的孔隙结构介于I类煤和Ⅴ类煤之间;对于I类煤和Ⅴ类煤,采用表征原生孔隙和构造孔隙双孔隙特征的模型获得的损失瓦斯量误差低于10%。研究结论对煤层瓦斯含量测定具有重要意义。

The gas loss quantity is the basic data to accurately obtain the gas content in coal seam. Through laboratory tests and comparative analysis on different calculation models of gas loss quantity,it showed that when adopting the traditional t method and powerfunction method to obtain the gas loss quantity,the conformance of class II,III and IV coal were better,with the error less than 20 %,while the errors of gas loss quantity for class I and V coal were 25 %- 31 %. The errors were caused by the difference of pore structure in coal. The primary pores were in the majority for class I coal,and the structure had the greatest influence on the pores of class V coal,while the pore structure of other classes coal lay between class I coal and class V coal. The errors of gas loss quantity obtained by the model with representation of dual pore characteristics about primary pore and structure pore were less than 10 % for class I coal and class V coal. The results are of great significance for the measurement of gas content in coal seam.