煤矿瓦斯智能抽采理论与调控策略

基于瓦斯抽采的安全原则与效率原则,提出了瓦斯智能抽采的原理;建立了瓦斯抽采管网中瓦斯-空气混合气体流动控制方程,以最大瓦斯抽采纯流量为目标函数,建立了瓦斯抽采管网参数的优化模型,分别从瓦斯体积分数、流量以及效能比等参数约束条件定量判定瓦斯抽采安全与效率;以上述模型为基础,针对钻孔抽采区域温度高于临界温度、钻孔抽采纯量低于抽采纯量下限,以及钻孔抽采浓度低于瓦斯安全浓度下限等工况条件展开理论分析和数值计算,提出了相应的瓦斯抽采系统优化策略,通过协同调整不同抽采钻孔的阀门开度和抽采泵转速,有效提高了抽采瓦斯体积分数、效能比和抽采纯流量,并提出了相应的瓦斯抽采系统优化策略。最后,设计了由数据感知模块、通信传输模块、数据处理与决策模块、控制模块等部分组成的瓦斯智能抽采系统,开发了基于物联网的智能调节阀门,阀门的感知模块包括温度传感器、瓦斯浓度传感器和气压传感器等,通讯模块将数据上传至云存储端,通过电脑网页和手机客户端实现监测与控制;发明了采用高分子减阻剂提高水环真空泵效率的技术方法,以高分子减阻溶液作为水环真空泵的工作介质,有效降低了液环的湍流损失和流体与泵体过流部件的摩擦损失,并开发了地面全封闭式和井下直注式2种瓦斯抽采泵节能系统,该项技术在山西潞安集团余吾煤业成功应用,节电率和节水率分别达到22.5%和66.7%,为瓦斯智能高效抽采提供了借鉴。

Intelligent gas extraction and control strategy in coal mine

Precise gas drainage will be the way of gas control in the future.Currently,there are many problems in gas extraction,such as the unreasonable distribution of negative pressure,no timely regulation and control,high energy consumption and poor safety in underground gas drainage.Therefore,the principle of precise gas drainage is proposed based on the safety and efficiency principles.The flow governing equations of methane air mixture gas in drainage system are established.A parameter optimization model for gas drainage pipe network is built with the maximum pure gas drainage flow rate as the objective function.According to this model,the safety and efficiency of gas drainage are quantitatively determined from the constraints of single parameters such as gas concentration,flow rate and efficiency ratio etc.On the basis of the model,theoretical analysis and numerical calculation are carried out under the working conditions of temperature in drainage area which is higher than the critical temperature,the pure flow rate of borehole drainage which is lower than the prescribed minimum pure flow rate of gas drainage,and the gas concentration which is lower than the prescribed minimum of safety gas concentration.Also,the corresponding optimization strategy of gas drainage system under the characteristics of borehole gas drainage is put forward,which effectively increases the gas drainage concentration,efficiency ratio and pure gas drainage amount.On this basis,an intelligent gas drainage system consisting of data aware module,communication module,data processing and decision making module and control module is designed to realize the connection of things with things and things with human.An intelligent regulating valve is developed based on the Internet of Things (IoT).The data aware module includes the sensors of temperature,gas concentration and gas pressure,and the communication module uploads the data to the cloud storage,which provide the path to measure and control the system by PC web and mobile phone client.The technical method of improving the efficiency of the water ring vacuum pump with high polymer drag reducer is proposed,which greatly reduces the turbulence loss of liquid ring and frictional loss.The two kinds of pump energy saving system including surface closed type and underground direct injection type are proposed.The technology is successfully applied in Luan group of Shanxi province,which achieves the power saving rate of 22.5% and water saving rate of 66.7% and provides a basic support for gas precise drainage.