Optimization Of Mine Water Inrush Early Warning Probe Position And Correction Law Of Roadway Water Flow Monitoring Value

As one of the main underground disasters,mine water inrush will pose a serious threat to mine safety production.The early prevention and prediction work is indeed important,but at present,it is still difficult to completely avoid water inrush.Once a water inrush event occurs,the monitoring and prediction of water inrush flow and inundation range is particularly important.It can formulate a scientific and reasonable rescue plan for rescuers,Planning an accurate escape route provides valuable data support,minimizes the loss caused by the accident,and also has a certain guiding significance for the later drainage work.This paper mainly includes four aspects: firstly,select the appropriate water flow monitoring equipment and water level monitoring equipment;Secondly,the applicability analysis and error correction of water flow monitoring equipment are carried out;Then optimize the installation position of water level monitoring equipment in the whole mine;Finally,combined with the data obtained by water flow monitoring equipment and water level monitoring equipment,the prediction method of mine water inrush inundation range is put forward.(1)Water flow and water level monitoring equipmentThe advantages,disadvantages and applicable conditions of open channel water flow monitoring equipment and water level monitoring equipment in the market are summarized.Radar flowmeter is selected as mine water inrush flow monitoring equipment,and static pressure water level gauge is selected as mine inundation range monitoring equipment.Compared with other open channel water flow monitoring equipment,radar flowmeter has the following advantages: 1)it can realize non-contact measurement and can be installed on the roadway roof without affecting the normal use of the roadway;2)The roadway section shape can be customized,which is suitable for a variety of roadway section shapes;3)Unattended,data can be automatically transmitted to the control room.The selection of static pressure water level gauge is mainly based on the working principle.The liquid level measured by the equipment is the height from the measuring point to the free liquid level,which is suitable for the measurement of mine inundation range.(2)Performance and error analysis of water flow monitoring equipmentBased on the similarity principle,a tunnel water flow monitoring experimental platform is built in the laboratory to simulate the underground tunnel water flow,and the stability and applicability of the radar flowmeter are analyzed by the method of sample test;By comparing with the indication of electromagnetic flowmeter,the error of radar flowmeter is determined and corrected.The experimental results show that the radar flowmeter works stably and the reading is not affected by the underground environment(random floating objects,sediment in water and coal dust).The error consists of velocity error and water level error.The velocity error is negatively correlated with the surface velocity of water flow.The fitting formula of the absolute error of surface velocity and section average velocity is given.The main source of the error of the water level gauge is the resolution of the water level gauge.The experiment proves that the resolution of the water level gauge is 3mm.The method of correcting the water level error according to the average velocity of the section is proposed and tested.(3)Optimization of installation position of water level monitoring equipmentThe static pressure water level gauge is selected as the sensor of mine water level measurement.The water level measured by the static pressure water level gauge is the height difference between the installation point and the free surface.Based on this,it is proposed to install the static pressure water level gauge on the water storage node of the mine,that is,the node whose elevation of adjacent nodes is equal to or higher than it.Based on graph theory and set covering theory,the method of finding water storage nodes is given.(4)Prediction of water inrush inundation rangeMine water inrush generally occurs in the place where the coal and rock stress is unbalanced,and basically occurs in the heading face and mining face.The upward rising path of water flow in the case of water inrush in the heading face and mining face is analyzed in advance.The upward rising of water flow is divided into different stages according to the sequence of water breakthrough at the time of water storage node,and the water required for different water levels in each stage is calculated.When water inrush occurs in the mine,Through the monitoring of the water inrush flow,predict the water inrush volume after a period of time,calculate the branch that can be submerged by the flow in combination with the pre divided inundation stage,and predict the inundation range.