粉尘对煤矿井下作业环境造成重大危害, 高浓度粉尘不仅增加了作业人员罹患尘肺病的风险, 还会引起煤尘/瓦斯煤尘爆炸事故, 严重影响煤矿企业生产安全。煤矿采掘工作面采掘机械截割煤岩作业是产生粉尘的主要源头, 深入理解截割产尘机理是实现粉尘源头高效治理的关键。该文主要从截割产尘行为、 研究方法和影响机制3方面综述了煤矿井下采掘机械截割产尘机理的研究进展。在截割产尘行为方面, 总结了截割力理论计算模型和截割时煤岩体破碎产尘过程, 并分析了煤岩体破碎产尘过程的能量转化机制; 在研究方法方面, 介绍了国内外学者通过自主搭建实验平台进行的物理实验和基于有限元或离散元方法的数值模拟软件在截割产尘研究中的应用; 在影响机制方面, 探讨了煤岩体性质和截割机械工况参数等内外因素对截割产尘的影响。该文针对当前采掘机械截割产尘机理研究存在的难点, 提出了可能的研究方向。该文研究结果可为国内外学者研究煤矿粉尘治理技术提供参考。
Abstract
[Significance] Coal remains the most essential fossil energy source in China, with production from underground coal mines accounting for more than 80%. In underground coal mining operations, dust is a pervasive and hazardous material that can significantly compromise the safety and health of miners. High dust concentrations are associated with an increased incidence of pneumoconiosis and a heightened risk of catastrophic events, such as coal dust or gas explosions. The primary source of dust is the cutting processes of excavators and roadheaders during the extraction of coal and rock. Therefore, it is essential to comprehensively elucidate the mechanism of dust generation during cutting and heading operations for effective dust control in underground coal mines. [Progress] This paper presents an overview of the latest research developments in the field of dust generation, with a particular emphasis on three key areas: the behavior of dust generation during cutting, research methodology, and influencing mechanisms. First, regarding the behavior of dust generation during cutting by excavators and roadheaders, researchers have proposed several theoretical models to elucidate both the fragmentation processes of coal and rock bodies and the generation of dust under the influence of cutting. These models are based not only on the principle of energy conversion but also on the influence of the geometry of the cutting pick during the dust generation process. This provides a solid theoretical basis for understanding the physical nature of dust generation. Regarding the research tools employed, researchers have simulated the dust generation phenomena when mining machinery cuts coal and rock bodies through physical experiments conducted on self-designed experimental platforms. Researchers have also conducted numerical simulations using finite element or discrete element methods. These advanced experimental techniques elucidate the actual cutting conditions and offer a robust analytical tool for investigating the dust generation mechanism in depth. Additionally, this study provides a comprehensive analysis of the mechanisms influencing dust generation during cutting, examining both internal and external factors. These factors include the physicochemical properties of coal and rock, such as coal rank, moisture content, pore characteristics, strength, and brittleness, as well as the parameters of the cutting conditions, such as cutting depth, advance speed, drum rotation speed, and the morphology and arrangement of picks. [Conclusions and Prospects] Current research on the dust generation mechanism during cutting reveals several contradictions. Existing models often rely on simplified assumptions, neglecting the anisotropy of coal and the actual cutting conditions in the field, leading to discrepancies between the calculated results and experimental observations. Moreover, existing experimental platforms struggle to accurately replicate the motion of the cutting pick during actual operations. Although many studies have focused on the properties of coal and rock and dust characteristics, some of the conclusions are conflicting. Future research should prioritize the construction of full-scale experimental platforms and the development of high-precision monitoring technologies. Comprehensively investigating the dust generation characteristics of complex coal seams and quantifying the energy conversion mechanisms during the cutting process are crucial. These efforts are essential for improving the efficiency of cutting operations and achieving more effective dust control.
关键词
煤矿地下开采 /
粉尘 /
采掘机械 /
产尘机理
Key words
underground coal mining /
dust /
mining and tunneling machines /
mechanism of dust generation