Research On High Pressure Water Jet Slotting Technology And Its Application In Jinneng Colliery

With the continuous development of coal mining technology in China's coal industry and the increase in the depth of mining,the occurrence of gas is becoming more and more complex.Gas disasters have become one of the biggest safety issues in the production process of coal mines.The most fundamental and effective way to prevent gas disasters is gas drainage,but generally there are few pores and fissures inside low-permeability and high-burst coal seams,the gas extraction effect is not ideal,so it is necessary to seek a technical means to improve the breathability of coal seams and makes gas drainage more efficient.This study according Jinneng's actual production situation,provides a set of high-pressure water jet kerf technology which is suitable for Jinneng Coal Mine by theoretical research,numerical simulation and engineering experiments.The main research,contents and conclusions are as follows:(1)Based on the technical,parameters of high-pressure water jets and the actual conditions of Jinneng's three-tier coal,the basic numerical model of high-pressure water jet kerf is established by using the particle flow discrete element model PFC2D software,and after high-pressure water jet slicing,The cracks in the coal body have been increased a lot,and the gas flow in the coal seam has been significantly improved.(2)Based on the mechanism of high pressure water jet dynamics and the mechanism of high pressure water jet coal breaking,the process and main parameters of the high pressure water jet damage to the coal are studied.The damages to coal by high pressure water jets mainly include shear failure,tensile failure and internal damage.The main factors affecting the kerf are water jet pressure,water jet flow,slitting speed,kerf time.(3)FLUENT software was used to simulate the optimal nozzle structure and parameters,the main parameters and the main components of the high-pressure water jet slotting system were actually determined in combination with the Jinneng coal mine site.Through the 600 special return air Lane in the No.31 coal zone of No.3 Coal Mine of Jinneng Coal Mine,the effects of physical kerf,the effective evacuation radius of kerf drilling,and the effect of kerf on the drainage result were investigated.Through the study,provides a set of high-pressure water jet kerf equipment to Jinneng Coal Company which is suitable for the actual site and which provides technical support for improving gas extraction more efficient,effectively alleviating mining tension and ensuring the safe and efficient production of coal mines.This study provides a reliable reference for Water Jet Slotting Technology popularization and application in China.