中文摘要：

矿井密闭巷道的瓦斯排放属于矿井通风管理中重要的非正常作业，应对瓦斯排放的过程进行详细的设计以保证排放过程的安全。在瓦斯排放速度不变的条件下，假设巷道内瓦斯与新鲜风流瞬间充分混合，则巷道瓦斯浓度在排放过程中均匀变化。在与传统瓦斯排放方法比较的基础上。建立一种新的瓦斯排放数学模型。该模型推导了巷道内瓦斯浓度与排放速度、排放时间和全负压通风量等参、变量之间的依赖关系。通过计算在排放过程中的危险时间长度及排放风险，得出危险排放时间与初始浓度无关、排放风险与排放率无关的重要结论。最后通过一个瓦斯排放算例。证明了该数学模型的优越性。

英文摘要：

As an important abnormal operation of coal mine＇s ventilation management, the design of gas drainage from a sealed lane in coal mine should be paid more attention to the safety of drainage process. On condition that the gas drainage rate is unchanged, the methane concentration during the gas drainage process would uniformly vary; the fresh air flow is able to be mixed sufficiently with those containing more methane in the lane. Based on the comparison with the traditional methods for gas drainage, a new mathematics model for gas drainage is established; the model deduces the dependent relation among parameters involving the methane concentration in drained lane, the flow rate of gas drainage, gas drainage time, and the flow rate under the total negative pressure ventilation system. Furthermore, the length of dangerous time and the risk during the gas drainage process are calculated in order to obtain an important conclusion, that is, the dangerous time of gas drainage is irrelevant to the initial concentration, the risk of gas drainage has noting to do with the ratio between the gas drainage flow rate to the volume of drained lane. Finally, a case study of gas drainage is adopted to validate the new proposed model.