压差对采空区空气微流动场影响的模拟研究

Simulation on effects of micro-flow air in goaf on changing pressure differences

采煤工作面两端压差是影响采空区空气微流动的一个重要参数,为研究U型工作面采空区微流动场在工作面两端压差变化情况下的分布规律,运用GAMBIT建立采空区多孔介质模型,应用流体力学软件FLUENT模拟不同压差下采空区的空气流场。研究表明,随着工作面两端压差的增加,漏风流场宽度加大,并且压差对采空区进风巷和回风巷处的漏风流场分布规律影响较大,对中部漏风流场的分布规律影响较小;同时,压差的变化也会对采空区深部的气体造成微小的流动,产生"呼吸"、"吞吐"效应。

This paper arises from the deeper understanding that the pressure difference at both ends of coal mining face holds an important parameter affecting the air flow in goaf. The study aimed at investigating the law underlying how a micro-flow field distributes in goaf of U-shaped working faces exposed to the changing pressure at both ends of working face,produces the porous media model of goaf using GAMBIT,and simulates the air flow field in the goaf under the pressure change using the hydrodynamics software FLUENT. The study shows that along with an increase in pressure difference comes a wider air leakage zone; and the pressure differences have a great influence on the distribution law behind the air leakage flow field of the goaf intake airflow roadway and return airway,but a little effect on the law governing the air leakage flow field on the middle part; and at the same time,pressure changes can cause the micro-flow of gas in deep goaf,with consequent breathing and throughput effects.