【作者】 刘金金；

【导师】 高建良；

【作者基本信息】 河南理工大学 ， 安全技术及工程， 2011， 硕士

【摘要】 随着矿井采掘深度的不断增加,瓦斯灾害越来越严重,为了有效防止瓦斯积聚引起瓦斯爆炸与瓦斯突出事故就需要准确预测矿井巷道瓦斯分布,但瓦斯分布又受巷道风流流场的影响,因此,需要对风流流场进行计算。在模拟解算掘进工作面风流流场的过程中,在湍流充分发展区域使用RNGk-ε双方程模型,对巷道中风速分布进行数值模拟,流场入口风流的湍动能k和湍动能耗散率ε的值有着不同的计算方法。本文通过计算湍动能k和湍动能耗散率ε采用不同取值时的风流流场,并与试验结果进行对比,确定了局部通风流场湍动能k和湍动能耗散率ε的取值方法,得到了与实际比较接近的掘进工作面流场。在研究掘进工作面风流流场的基础上,确定了倾斜掘进巷道中瓦斯与空气混合的数学模型,对倾斜巷道中倾角、风量对瓦斯分布与瓦斯积聚的影响进行了数值模拟研究。模拟结果表明,在回风瓦斯浓度较低的情况下,倾斜巷道掘进工作面仍存在一定范围的高浓度瓦斯区域。当压入风量、倾斜角度和回风流中瓦斯平均浓度均相同时,向上倾斜掘进工作面的高浓度瓦斯区域比向下倾斜的高浓度瓦斯区域大。当回风流中瓦斯平均浓度不变时,随着风量和瓦斯涌出量的增加,向上倾斜掘进工作面的高浓度瓦斯区域和向下倾斜的高浓度瓦斯区域之间的差距逐渐减小,但向上倾斜的高浓度瓦斯区域仍比向下倾斜的大。当倾斜角度和瓦斯涌出量均相同时,消除瓦斯超限区域,向上倾斜巷道需风量比向下倾斜时需风量大。更多还原

【Abstract】 With mine coal extractive depth increasing gas disasters problem worsening. In order to effectively control gas explosion and gas outburst accidents caused by gas accumulation,we must accurately predict mine gas distribution in mine laneway.But the gas distribution is influenced by the airflow.So, we must study on airflow in mine laneway. In the process of simulating the heading face airflow field, the turbulence energy k and dissipation rateεhas different calculation methods in the flow field entrance when fully developed areas are in RNG model for a numerical simulation of airflow distribution. This article Simulated the flow field with different turbulent kinetic energy k and dissipation rateεvalues, and compared with the experimental results, determined the turbulent kinetic energy k and dissipation rateεcalculation method in auxiliary ventilation field simulation calculating,obtained the heading face flow field close to the actual.based on the heading face flow field, determined the mathematical model of the gas and air mixture in sloping heading face, The influence of the angle of inclination and quantity of ventilation airflow to methane distribution is studied.It is shown that, if the average methane concentration in return airflow is lower , there is still a range of high-concentration methane area in sloping heading face. the zone with high concentration gas is larger in upward heading face than that in downward heading face. The difference in zone with high concentration methane becomes decreases with the increase of the air quantity and methane emission rate if the average methane concentration in return airflow is same. But the zone with high concentration methane in upward heading face is still larger than that in downward heading face with forced auxiliary ventilation. if the angle of inclinationand the gas emission in sloping heading face are the same.The airflow quantity required to eliminate methane collection is greater at upward heading face than at downward heading face.更多还原