【摘要】 为增加煤层透气性,提高瓦斯(甲烷)抽采效率,基于损伤力学和空气动力学,研究液态CO2爆破的原理,分析爆破过程中爆破器主管内高压气体的压力时程变化。采用FLAC3D数值软件,建立煤层液态CO2爆破有限差分本构模型,计算不同地应力下单孔爆破有效影响半径,数值模拟多孔连续爆破。模拟结果表明,单孔爆破有效影响半径随着地应力的增加近线性减小;有控制孔时多孔爆破影响范围明显大于无控制孔时。在井下进行液态CO2爆破工业试验。其结果是,爆破后煤层透气性系数提高17.49~22.76倍,平均瓦斯抽采浓度和混合气体流量分别增加56.4%和42.8%。更多还原

【Abstract】 In order to increase coal seam permeability and improve gas( methane) extraction efficiency,on the basis of damage mechanics and aerodynamics,the principle of liquid CO2 blasting was studied,and the pressure of CO2 in the main pipe of blasting device as a function of time in the process of blasting was analyzed. Using FLAC3 Dnumerical software,a finite differential constitutive model of liquid CO2 blasting of coal seam was established for calculating effective influencing radius of a single hole blast under different ground stress values. Numerical simulations of multi hole continuous blasting were conducted under the conditions of having control holes and having no control holes. The results show that the effective influencing radius of a single hole blast decreases linearly with the increase of the ground stress value,and that the multi hole blasting influence scope with control holes is obviously larger than that with no control holes.An underground industry experiment on liquid CO2 blasting was carried out. The results observed are as follows: the permeability of coal seam increased by 17. 49-22. 76 times,the average gas concentration and extraction mixture flow of a single hole respectively increased by 42. 8% and 56. 4%.更多还原