围岩应力与微波脉动加热耦合作用下煤体的改性增渗机制研究

Improving coal seam permeability is the key to achieve efficient gas extraction and prevent gas disaster. Microwave heating can promote the gas drainage efficiency of coal seam by promoting gas desorption and permeability. The existing research does not entirely reveal the response characteristics of coal in the microwave field under confining stress. Moreover, there are a few works has a focus on the effect of microwave cyclic heating on coal, which may have more complicated influence on pore and fracture of coal than that induced by the microwave continuous heating. This project intends to study the effect of microwave cyclic heating and confining stress on coal by means of experiment, numerical simulation and theoretical analysis. The thermal stress induced by microwave irradiation under confining stress will be studied. Furthermore, the effect of confining pressure and microwave cyclic heating on pore and fracture of coal will be studied. It also gives attention to the fatigue damage of pore and fracture induced by microwave cyclic heating. Moreover, the influence of microwave cyclic heating on the gas desorption and permeability is studied. The research results can improve the existing theory of the damage mechanism of coal under microwave irradiation, and provide scientific basis and technical support to the application of microwave heating in the field.

煤层增透是实现矿井瓦斯高效抽采和煤层瓦斯动力灾害防治的关键。微波注热能够通过促进煤层瓦斯解吸与运移来提高低渗透煤层瓦斯的抽采效率。现有的研究未能充分揭示围压环境下煤体孔隙-裂隙结构在微波场中的响应特征。同时，相对于持续性加热，微波脉动加热对煤体孔隙-裂隙结构的影响更为复杂，而现有的研究也未能充分揭示其影响规律。本项目拟借助物理模型试验、数值模拟和理论分析相结合的方法，探究围岩应力环境下微波诱发的煤体热应力分布特征，阐明围岩应力与微波诱发热应力耦合作用下煤体孔隙-裂隙结构的损伤机制，明晰微波脉动加热下煤体孔隙-裂隙结构的损伤叠加机制，揭示围岩应力环境下微波脉动加热诱发的疲劳损伤对煤体瓦斯解吸运移规律的影响机制。研究成果可完善微波辐射下煤体孔隙-裂隙结构的损伤机制，为微波注热增透技术在深部煤层增透方面的应用提供科学依据和理论支撑，具有重要的理论意义和应用价值。

煤层增透是实现矿井瓦斯高效抽采和煤层瓦斯动力灾害防治的关键。微波注热能够通过促进煤层瓦斯解吸与运移来提高低渗透煤层瓦斯的抽采效率。为了深入理解微波辐射下煤岩的响应特征，本项目借助物理模型试验、数值模拟和理论分析相结合的方法，探究围岩应力环境下微波诱发的煤体热应力分布特征，阐明围岩应力与微波诱发热应力耦合作用下煤体孔隙-裂隙结构的损伤机制，明晰微波脉动加热下煤体孔隙-裂隙结构的损伤叠加机制，揭示围岩应力环境下微波脉动加热诱发的疲劳损伤对煤体瓦斯解吸运移规律的影响机制。研究成果可完善微波辐射下煤体孔隙-裂隙结构的损伤机制，为微波注热增透技术在深部煤层增透方面的应用提供科学依据和理论支撑，具有重要的理论意义和应用价值。