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基于通风网络理论模型演化得到采空区走向及倾向的漏风阻力系数分布,综合考虑了采面的回采速度、顶板岩性以及采空区倾向上顶板的沉降量不同等因素影响。采用专业的流体力学计算软件Fluent对桃园矿1033工作面及其采空区进行了流场数值模拟,得到了工作面的漏风量分布及采空区漏风流场分布。模拟结果表明,工作面向采空区漏风区域主要发生在倾向上靠进风侧0～10 m范围,并有部分漏风量在工作面倾向从中间点前流回至工作面,采空区内的流场等值线并不完全呈对称分布。采用工作面埋管取气分析采空区内氧气体积分数,得到了采空区内氧气体积分数分布规律。试验结果表明,沿着采空区走向,氧气体积分数逐渐下降;在采空区倾向上,回风巷氧气体积分数下降最快,进风巷氧气体积分数下降最慢。综合考虑采空区内的滤流速度和氧气体积分数分布,得到了采空区自燃“三带”范围。在采空区回风巷,氧化带距离工作面范围为11～38 m;在采空区进风巷,距离工作面范围为23～76 m;在中部,距离工作面范围为12～66 m。最后,计算得到工作面安全回采速度为2.2 m/d。
Based on the evolution of the ventilation network theory model, the distribution of the air leakage resistance coefficient of the gob-free zone is obtained, taking into account the factors such as the recovery rate of the mining face, the roof lithology and the settlement of roof in the goaf. The fluid field numerical simulation of 1033 working face and its goaf of Taoyuan Mine were carried out by professional fluid mechanics calculation software Fluent. The distribution of air leakage in working face and the leakage flow field in goaf were obtained. The simulation results show that the air leakage area in the working face mainly occurs in the range of 0-10 m on the leeward side and some of the air leakage tends to flow back to the working face from the midpoint before working face. Flow contour is not completely symmetrical distribution. Adopting pipe-sampling of working face to analyze the oxygen volume fraction in the gob area, the distribution rule of oxygen volume fraction in gob area was obtained. The results show that along with the gob area, the oxygen volume fraction decreases gradually. In the gob area, the oxygen gas volume fraction of return airway decreases fastest and the oxygen gas volume fraction of air inlet passage decreases slowly. Considering the filtration velocity and the distribution of oxygen volume fraction in the gob area, the spontaneous combustion of the goaf was obtained. In the air return airways in the goaf, the range of the oxidation zone is from 11 to 38 m; in the air intake of the goaf, the working range is from 23 to 76 m; in the middle, the working range is from 12 to 66 m . Finally, the calculated working face safe recovery rate of 2.2 m / d.