【作者】 曾锐；

【导师】 杜长龙；

【作者基本信息】 中国矿业大学 ， 机械设计及理论， 2014， 博士

【摘要】 随着煤炭资源的日渐减少，我国国有大中型煤矿对于坚硬煤岩的采掘技术越来越重视。由于一般采煤机截割坚硬煤岩的能力不足，因此现有技术条件下对坚硬煤岩开采难度较大。为了能够安全高效地开采坚硬煤岩资源，本文提出一种新型的截割系统，即对综采机械化设备中的采煤机加装联合截割装置，形成可以有效截割坚硬煤岩的滚筒式采煤机—高压水射流联合截割系统。该系统在采煤作业时还具有除尘、湿润和冷却截割区、减少发火危险等许多正面效应，是提高社会效益和经济效益的研究方向。本文对采煤机滚筒与高压水射流的结构特性分别进行了阐述分析，对二者自身结构的各项指标参数及其对截割效果的影响进行了总结，并推导了高压水射流紊流时均运动方程。对坚硬煤岩的物理参数和孔裂隙度进行了研究分析，总结了常用的复合型断裂判据，为联合截割坚硬煤岩机理研究打下基础。基于截齿、水射流破岩机理,将截齿与高压水射流对坚硬煤岩联合截割的过程分为四个阶段，用以指导联合截割坚硬煤岩数理分析模型的建立。在截齿破岩和高压水射流破碎坚硬煤岩理论研究的基础上，从水射流破岩经典理论、冲击动力学及损伤力学入手，结合分形理论，研究联合截割坚硬煤岩机理，揭示联合冲击动载、煤岩体应力分布变化规律以及煤岩损伤本构关系，得到了联合截割系统在坚硬煤岩内部产生的应力波叠加方程和含有夹矸层坚硬煤岩体内的应力波叠加方程，为判别坚硬煤岩内部损伤及孔裂隙发展情况提供了理论依据。采用基于突变理论的能量观点对坚硬煤岩受到联合截割的冲击崩落损伤进行了宏观上的分析，解决了静载、动载条件下各种破岩强度理论之间观点不一致所带来的争论，并得到了联合截割崩落坚硬煤岩的冲击能量判别式。同时，从突变、采动渗流等理论的角度，建立起全新的、能够更加准确描述坚硬煤岩在联合截割作用下失稳条件的数理分析模型。搭建“单截齿—喷嘴联合截割试验台”进行单截齿—喷嘴联合截割试验，对联合截割试验中所涉及的截齿冲击角、截割速度、切削厚度、水射流的靶距、入射角、水射流作用点与截齿齿尖的横向间距等参数进行系统的试验，研究各个参数组合对主要截割性能的影响，探求联合截割规律，确定联合截割滚筒的最佳结构参数；搭建“滚筒—水射流联合截割试验台”进行采煤机滚筒—高压水射流联合截割试验，解决了系统旋转密封问题，完成了联合截割试验滚筒的设计制造，对比验证了不同截割方式的截割效果，探寻出联合截割运动参数对联合截割部截割的影响规律。试验结果验证了本文关于联合截割过程的理论分析，证实了滚筒采煤机—高压水射流联合截割系统对坚硬煤岩体实施截割作业的可行性和有效性。本文相关的理论和试验研究对该系统的工业化生产应用提供了有力的技术支持和充足的实践经验。更多还原

【Abstract】 With the decreasing of soft coal seam resource, the state-owned large andmedium-sized coal mines are paying more and more attention to the technology ofmining hard coal-rock seam. It is difficult to mine hard coal-rock seam under existingtechniques, because the cutting ability of common drum shearer is not adequate. Inorder to mine the hard coal-rock seam resource safely and high-effectively, a newcutting system is proposed in this dissertation. In the new cutting system, thecombined cutting device is installed on the drum shearer of full-mechanized miningequipments to form the combined cutting system of drum shearer and high pressurewater jet which can cut hard coal-rock effectively and has a lot of positive effects,such as dust removal, wetness, cutting region cooling, fire danger decreasing and soon. It is the research direction of improving social and economy benefits.In this dissertation，the structure characteristics of drum and high pressure waterjet are researched and analyzed, and the equation of high pressure water jet turbulentflow averaged velocity is deduced. The physical parameters and porosity of hardcoal-rock are described and analyzed, and mixed-mode fracture criterions aresummarized, which is prepared to the research of the combined cutting mechanism.Based on the rock breaking mechanisms of pick and water jet, the process ofcombined cutting hard coal-rock is divided into four phases. In order to show up thestatic loading of combined impact, the variation law of coal-rock stress distributionand the constitutive relationship of coal-rock damage, the classic theory of rockbreaking by water jet, impact dynamics, damage mechanics and fractal theory areapplied. And the equations of surface damage and hard coal-rock stress wavessuperimposition damage are obtained, which provides the theoretical basis to criterionof hard coal-rock internal damage and porosity development.Based on the energy point of catastrophe theory, the discriminant of combinedinstability caving damage is obtained. The mining seepage theory is applied, and thebran-new mathematical-physical analysis models are built to describe the instabilityprocess and conditions of hard coal-rock under combined cutting.The single pick&nozzle combined cutting test-bed is built and the test blocksare prepared to test the parameters of pick impact angle, impact speed, cuttingthickness, target distance, incidence angle, cutting distance between pick-tip andwater jet point, and so on. Through the single pick&nozzle combined cutting tests, the best parameters combination is obtained, the combined cutting laws are foundedand the process and mechanism theory analysis of the combined cutting are verified.The drum&water-jet combined cutting test-bed is built to test the drum shearer&high pressure water jet combined cutting, in which the design and manufacture ofcombined cutting drum is finished, the problem of rotary sealing is solved, the cuttingeffects of different cutting modes are contrasted and the influence laws of motionparameters on combined cutting are found.The theoretical analysis of combined cutting process in this dissertation isvalidated by the physical phenomenon and results of combined cutting experiments.The combined cutting system of drum shearer&high pressure water jet is proved tobe a necessary, feasible and effective technique to realize the hard coal-rock’s cutting.The sufficient technical supports and practical experience for the combined cuttingsystem to be manufactured through industrialization are acquired by the theory andexperimental research of this dissertation.更多还原