高压水射流冲击力分布特性及增透关键参数研究

By establishing the relationship model of high-pressure water jet fluid properties and coal properties, the key parameters is analyzed which affected the capacity and efficiency of coal breaking, a Simulation device on high-pressure water jet breaking coal is developed. By numerical simulation, simulation experiment and other technical means, the effect of hydraulic parameter and design parameters of nozzle on jet morphology is monitored and analyzed, the attenuation characteristic of high-pressure jet impact on transverse and longitudinal direction is revealed, the design parameter of the nozzle inner wall of the optimal water jet equivelocity core segment is determined. Through numerical simulation and field test, the relationship of drilling parameters of high pressure water jet, coal body occurrence characteristic value and the parameter of gas drainage in coal seam(extraction radius, negative pressure, time etc) was determined, the parameters selection criteria of gas drainage in high pressure water jet permeability enhancement was made, in order to improve the effect of gas drainage in low permeability coal seam and reduce the occurrence of gas accidents.

依据构建高压水射流流体属性与煤体属性的关系模型，分析影响破煤能力及效率的关键参数，研制高压水射流破煤仿真实验装置。通过数值模拟、仿真实验等技术手段，监测分析水力参数、枪嘴设计参数对射流形态的影响，揭示水射流冲击力在横向、纵向的衰减特性，确定水射流等速核心段最优时的枪嘴内壁设计参数。通过数值模拟和现场测试，确定高压水射流钻孔参数、煤体赋存特征值与煤层瓦斯抽采参数（抽采半径、负压、时间等）的关系，制定高压水射流钻孔增透条件下瓦斯抽采参数选取标准，提高低透气性煤层瓦斯抽采效果，减少瓦斯灾害事故发生。

课题依据自行研制的水力钻孔防突装置，构建高压水射流流体属性与煤体属性的关系模型，分析影响破煤能力及效率的关键参数。.通过数值模拟、仿真实验等技术手段，监测分析水力参数、枪嘴设计参数对射流形态的影响，揭示水射流冲击力在横向、纵向的衰减特性，确定水射流等速核心段最优时的枪嘴内壁设计参数。采用理论分析、数值模拟与力学实验相结合的方法，深入研究了水射流破煤及成孔后煤体破裂特征，揭示了煤体裂隙发育规律、影响因素及作用规律。.采用显示动力学软件模拟分析了水射流破碎煤岩体过程，探究了煤岩体在水射流冲击下的破碎规律及裂隙发育状态。分析有/无围压时，射流成孔的过程及形态，阐明了煤岩体受射流打击力作用形成横纵向裂隙并逐渐延伸成裂隙网的过程..开展了相似材料模型受压实验，采用全场应变和声发射系统，分析射流成孔煤体在应力作用下的变形规律和裂隙发育特征，水射流成孔煤体结构在围岩应力作用下发生较为明显改变，煤体裂隙不断发育扩张。建立类椭球形孔洞数值模型，分析了孔洞受压变形特征、出煤量与孔洞变形关系；孔洞出煤量与顶部最大主位移量呈正相关，出煤量越多，煤体裂隙发育越充分。.从理论和实验角度证明了研究成果可提高低透气性煤层瓦斯抽采效果，减少瓦斯灾害事故。