【作者】 高振周；

【导师】 朱建安；

【作者基本信息】 河南理工大学 ， 机械工程， 2010， 硕士

【摘要】 高压水射流切割技术是近30多年来发展起来的新型冷切割工艺,相对于其他热切割工艺,如激光束、电子束和等离子等,它具有良好的切割、磨削、冲蚀、粉碎功能,且没有切割热,能排除热变质、热变形的可能性,同时水射流切割比其他常规的切割方法更为经济、有效。由于水射流切割是在常温下进行,切割时无火花、无尘、无味、无气体产生、加工安全、振动小、噪音低,因此特别适合于防水、防爆、防反应、防瓦斯等危险场合。由于我国煤层地质条件复杂,赋存状况多变,煤与瓦斯突出发生次数多,强度大,一旦发生瓦斯爆炸,将造成人力、财力的巨大损失。提高煤层瓦斯预抽率是矿井区域防治煤与瓦斯突出的强有力措施之一,通过预抽可降低煤层中的瓦斯含量和瓦斯压力,增大煤层透气性,降低煤岩应力,从而消除煤层瓦斯的突出隐患。水力冲孔防突措施是在进行石门揭煤或采掘工作之前,使用高压水射流,在突出危险煤层中,冲出若干直径较大的孔洞,冲孔过程中排出了大量瓦斯和一定数量的煤炭,因此在煤体中形成一定的卸压、排放瓦斯区域,在这个区域内可预防瓦斯突出的发生。本课题在研究过程中,首先设计出了一种结构新颖的水力冲孔喷嘴,然后采用理论研究、数值模拟、试验验证的方法,对其结构参数进行优化。通过对喷嘴结构和冲孔特性参数之间关系的探讨,建立了相应的理论模型,借助于FLUENT软件对喷嘴内外部流场进行数值模拟,研究喷嘴结构参数对冲孔性能的影响,为参数优化提供理论依据。在数值模拟的基础上,进行喷嘴的冲孔试验,对模拟结果进行了验证。研究结果表明,经优化设计的水力冲孔喷嘴冲孔效果良好。更多还原

【Abstract】 High-pressure water jet cutting technology is a new cold-cutting process and developed in the past 30 years, compared to the other thermal cutting process, such as the laser beam, electron beam and plasma, etc. It has good cutting, grinding, erosion, grinding function, and no cutting heat, to get rid of thermal metamorphism, the possibility of thermal deformation, While water-jet cutting is more economical and effective than other conventional cutting method. As the water-jet cutting is carried out at normaltemperature, when cutting without sparks, dust-free, tasteless, non-gas production, processing safety, little vibration, low noise, therefore it is particularly suitable for water-proof, explosion-proof, anti-reaction, anti-gas and other dangerous situations.Because China’s coal geology conditions are complicated, existed condition complicated, gas outburst is extremely serious, and the number of occurrence is more, the number of gas emission is also great, the event of a gas explosion will cause a great loss of human and financial resources. Coal Seam Gas pre-pumping rate increase is a strong measure to combat the powerful coal and gas outburst in one of the measures, the pre-drainage can reduce the counter of gas and gas pressure in the dust, so that the coal seam permeability increase and coal stress reduce,thereby eliminating the outstanding risks of coal and gas. Hydraulic releasing hole measure is making before exposing coal or mining work, using high-pressure water jet, highlighting the risk of coal seam, out of a number of large diameter holes, the process of releasing hole discharges a large number of gas and a number of coal, so a certain degree of pressure relief and emission gas area forms in coal, can prevent the occurrence of gas outburst in this region.In the course of the topic study, designed a novel structure for hydraulic releasing hole nozzles firstly, then, using theoretical analyses、numerical simulation and experimental researches to optimize its structure parameters. By analyzing the relationship between the structure and the characteristic parameters of the nozzle, established the corresponding theoretical model, and made use FLUENT software on the internal and external flow field simulation of nozzle, study on the structural parameters influence to punching nozzle performance, provided a theoretical basis for the optimized parameters. Based on the numerical simulation, carried hydraulic releasing hole nozzle testing, and verified the simulation results. The results show that the flushing effect of the optimized hydraulic releasing hole nozzles is good.更多还原