含瓦斯煤渗透特性对动态密封的响应机制

In allusion to the incident difficulty encountered in high-efficiency dynamic sealing for gas extraction, this paper studied the response mechanism for permeability characteristics of gas-filled coal to dynamic sealing based on the relationship of pressure gradient to flow rate by using research methods in adverse subjects. Firstly, characteristics of deformation, disability and seismic response were got under different loads and corresponding deformation and disability mechanism were studied by using MTS electro-hydraulic triaxial servo test system. Secondly, criterion for disability were put forward and dynamic sealing model was constructed based on the permeability characteristics got from permeability test for gas-filled coal samples under different level of loads. Finally, 3D analogical simulative experimentation was implemented to simulate the whole process of dynamic sealing, revealing the response mechanism for permeability characteristics of gas-filled coal to dynamic sealing. The success of this project contribute to solve the difficulty encountered in high-efficiency dynamic sealing, providing novel theory and method.

针对当前本煤层瓦斯抽采钻孔高效密封的难题，基于流体渗流取决于压差的原理，采用多学科交叉的研究方法，在动态密封的基础上，提出了含瓦斯煤渗透特性对动态密封的响应机制。首先，利用MTS电液三轴伺服试验系统，研究不同载荷下含瓦斯煤的变形、失稳、声发射特征，探讨封孔段的变形、失稳机制。其次，通过不同载荷下原煤煤样的瓦斯渗透试验，获得在不同变形、失稳阶段含瓦斯煤渗透率的瓦斯压力效应，得到封孔段的失稳判据并建立基于含瓦斯煤渗透特性的本煤层瓦斯抽采钻孔动态密封模型。最后，利用三维含瓦斯煤开采物理相似材料模拟实验平台模拟动态密封全过程，并最终揭示含瓦斯煤渗透特性对动态密封的响应机制。本项目研究将有助于解决本煤层瓦斯抽采钻孔高效密封的难题，并为钻孔密封提供新的理论和方法。

本项目将针对含瓦斯煤渗透特性对动态密封的响应机制，采用实验研究、物理模拟和理论分析等手段系统研究动态密封过程中的关键影响因子。通过研究，得到本煤层易失稳瓦斯抽采钻孔封孔段的变形、失稳机制，得出封孔段的失稳判据，建立基于含瓦斯煤渗透特性的抽采钻孔动态密封模型，获得动态密封过程中含瓦斯煤渗透特性的动态变化规律，并最终揭示含瓦斯煤渗透特性对动态密封的响应机制，为实现瓦斯抽采钻孔高效密封奠定基础。本项目的成功将有助于解决本煤层易失稳瓦斯抽采钻孔密封难的问题，并为钻孔密封提供新的理论和方法。