掘进机镐形截齿破碎煤岩产尘机理及预测方法研究

Roadheader crushing coal and rock is the root cause of the dust generated in fully mechanized heading face. However, because of the unclear understanding of basic issues such as the dust generation mechanism and the influencing mechanism, there is lacking the methods for predicting the amount of dust generation. It results in blindness and extensiveness exist in the dust prevention and control in fully mechanized heading face, which seriously restricts the high efficiency and low cost in dust-hazard prevention. For this purpose, this project studied characteristics of the process in the conical teeth of road header rolling-shearing coal rock and forming crushing zone (pulverized nucleation), the initiation and coalescence characteristics of the microcracks in the crushing zone, and the formation and extension characteristics of macrocracks, crack shear movement and its effect on its surface morphology, the distribution of pulverized nucleation stress field, and characteristics of dust released by stress relief, reveals the mechanism of dust generation for the roadheader crushing coal rock. Explore the influence and mechanism of the physical properties such as moisture content, mechanical properties such as grindability, chemical properties such as fuel ratio, cutting technology and ventilation methods acting on the dust production and particle size distribution, Definite the main controlling factors of the dust generation for coal rocks cutting in fully mechanized heading face. Study the intensity characteristic parameters of the dust generation for coal rock cutting in fully mechanized heading face, and the quantitative relationship between properties of coal rock, cutting parameters, ventilation parameters, surrounding rock stress and intensity characteristic parameters of the dust production, then propose the prediction index, model and methods of dust production for coal rock cutting. The project achievement will consolidate the theoretical foundation for dust prevention and control in fully mechanized heading face, and provide theoretical basis and scientific guidance for preventing dust at the source and removing dust economically and effectively.

掘进机截齿破碎煤岩是综掘面粉尘产生的根源，但由于对其产尘机理、影响机制等基础问题认识不清，继而缺少预测产尘量的方法，导致在综掘粉尘防治中存在盲目性和粗放性，严重制约粉尘危害的高效率、低成本防治。为此，本项目研究镐形截齿滚压煤岩体形成压碎区和粉化核的过程及演化规律、微观裂纹的萌生与聚并特性、宏观裂纹的形成及扩展特性、粉化核应力场分布规律、裂纹断裂面剪切运动及对表面形貌的影响、粉化核自由面形成条件及粉尘释放特性，揭示掘进机破碎煤岩产尘机理；探究含水率等物理性质、燃料比等化学性质、可磨性等机械性质和截割工艺、通风方式对产尘特性的影响及作用机制，探明影响煤岩截割产尘的主控因素；研究各类型综掘面煤岩截割产尘强度特征参数，煤岩性质、截割参数、通风参数、地应力与产尘强度的量化关系，提出煤岩截割产尘强度预测方法。项目成果有望夯实综掘粉尘防治理论基础，为源头减尘和高效、经济除尘提供理论依据和科学指导。

掘进机截齿破碎煤岩是综掘面粉尘产生的根源，但由于对其产尘机理、影响机制等基础问题认识不清，继而缺少预测产尘量的方法，导致在粉尘防治中存在盲目性和粗放性，严重制约粉尘危害的高效率、低成本防治。为此，本项目采用理论分析、实验室实验、数值模拟、现场试验相结合的方法，研究了“镐型截齿滚压-剪切破碎煤岩产尘机理”和“煤岩截割产尘影响机制及预测方法”这两个科学问题，取得了如下研究进展和成果：①提出镐形截齿截割煤岩产尘机理的“粉化核”假说，解析了截齿侵入煤体时压碎区和粉化核的形成过程，分析了粉化核应力场分布特征，揭示了齿尖压碎区裂纹萌生及扩展规律，推导了塑性区体积计算方法，从能量转换角度阐释了粉尘产生机理；②自主研发了镐形截齿破碎煤岩产尘试验系统，探明了煤岩理化性质与产尘特性的关系，揭示了工业分析组分、孔隙率、脆性对截割产尘特性的影响及作用机制；揭示了截割参数对产尘率及累计占比的影响机制，建立了截齿截割数值模型，探明了不同截割参数下煤体破裂的细观机制；开展了现场减尘应用试验，通过减小截齿齿尖锥角和截割头转速降低了掘进机截割产尘率；③基于代表性矿井综掘面现场条件，建立了产尘强度数据集，构建了基于机器学习、深度学习的产尘强度预测模型，提出了掘进面截割产尘强度预测方法。项目研究工作发表学术论文15篇，其中SCI论文10篇、EI论文5篇；出版专著1部；申请或授权国内外发明专利5件；获中国职业安全健康协会科学技术二等奖1项，江苏省科学技术三等奖1项；培养博士生3名，硕士生3名；参加了5次国内外学术会议，做邀请报告2次。项目研究成果可夯实矿尘防治理论基础，为源头减尘和高效、经济降尘提供理论依据和科学指导。