【作者】 张杰；

【导师】 刘何清；

【作者基本信息】 湖南科技大学 ， 供热、供燃气、通风及空调工程， 2011， 硕士

【摘要】 一直以来,粉尘治理都是矿井安全生产的一大难题。随着煤矿生产机械化程度的不断提高,实现了采煤工作面的高效生产,但是伴随而来的粉尘职业危害问题也不容忽视。尘肺病是煤矿工人主要的职业病,它不仅严重危害工人的生命健康,而且制约着煤炭企业的生产和发展。据统计,我国每年平均新增职业尘肺病患者约1.5万人左右,尘肺病死亡人数高达工伤死亡人数的六倍之多,数字触目惊心。目前,采煤工作面采用的降尘措施主要有煤层注水、喷雾降尘以及通风除尘等,这些措施使大粒径的粉尘得到了较好控制,但是仍然有大量的呼吸性粉尘扩散到采煤工人处。众所周知,个体防护是防治粉尘职业危害一个十分有效的方法。为此,本人借助流体力学、射流力学等基础理论和方法,深入研究了条缝射流的隔尘作用机理,将其与传统的安全帽结合,开展了将条缝射流隔尘理论应用于矿用安全帽中的防尘新方法的研究。研究的具体内容和取得的研究成果如下:1.研究内容:分析矿井粉尘运移规律,研究条缝射流隔尘机理并建立条缝射流隔尘效果评价标准,模拟分析不同工作参数条件下的条缝风口对其隔尘效率的影响,以期得出带条缝风口安全帽的优化设计结果。2.研究方法:在理论分析的基础上,借助CFD数值模拟软件,结合实验研究,得出有利于粉尘隔离的带条缝风口安全帽的设计参数。3.主要研究成果:(1)利用流体力学、射流力学等相关理论和方法,总结得出:条缝射流的抗扩散能力和卷吸作用是影响其隔尘效率的两个关键因素,具体表现为抗扩散能力与隔尘效率成正比,卷吸作用与隔尘效率成反比。在实际应用中,这两个方面的作用是相互牵制的,设计条缝口的工作参数时应综合考虑这两个因素。(2)针对带条缝风口安全帽隔尘的实际情况,笔者提出了射流“三区模型”,并建立了三个区域粉尘浓度的微分方程,最终得出反映条缝射流隔尘效果的固有特征项f。(3)通过对不同工作参数条件下的条缝射流进行数值模拟,得出有利于粉尘隔离的带条缝风口安全帽的设计参数:出口宽度为6mm左右,出流角度为10°左右比较合理,安全帽进气速度为7m/s较为合理。(4)对条缝射流隔尘进行了多种工况的相似模型实验,进一步考察了条缝口工作参数的变化对其隔尘效果的影响,得出了实验室条件下的条缝口设计参数。实验结果的规律总结与数值模拟的结论有着很好的吻合。更多还原

【Abstract】 Dust control has always been a big problem in the mine safety production. With the increasing of mechanization degree in mine production, make high efficient production of the mining face come true, but the following dust occupational hazard is not allowed to be ignored. Pneumoconiosis disease is the main occupational diseases of coal miners; it not only severely does harm to life health of workers, but also restricts the development and production of coal enterprises. According to statistics, every year China’s new professional pneumoconiosis disease on average 1.5million or so, death caused by pneumoconiosis disease is 6 times of the death of injury, the digital is horrible.At present, main dust-fall measures used in the coal face are coal water injection, spray dust and ventilation dust. These measures make large particle size of dust under control, but there is still a lot of repairable dust spread to coal mines. As is known to all, individual defends is a highly effective method to control dust occupational hazards. Therefore, using the theory of fluid mechanics, jet mechanics and so on, I made a deep research to the theory related to slit jet, combined with the traditional safety helmet, carried on the new method research that using the dust-isolating slit-jet theory to mine safety helmet. The specific contents of the study and obtained research results are as follows:1. Contents of the study: Analysed the diffusion motion law of dust ,made a deep research to the theory related to slit jet, established the evaluation standard of influence dust-isolating efficiency, through numerical simulation to slit-jet that on various different working parameters, got the good working parameters of dust-isolation slit-jet.2. Methods of the study: On the basis of theoretical analysis and with the help of numerical simulation soft, combining with experiments, this paper eventually got the inherent characteristics that reflect slit-jet’s isolation dust effect. 3. Main results of the study:(1)Through the use of fluid mechanics, jet mechanics and related theories and methods, it is concluded that fight diffusion capacity and volume-suck affection of the slit jet is two key factors that influence dust-isolating efficiency. This specific performance that fight diffusion capacity is proportional to dust-isolating efficiency, volume-suck affection is inversely proportional to the dust-isolating efficiency. In practical applications, this two effects are mutual contain, and should be taken into account in design the working parameters of slit-jet.(2)According to actual situation of safety helmet with slit-jet, the author puts forward the“three-region model”, and established differential equations about these three regional dust concentration, and eventually got the inherent characteristics that reflect slit-jet’s isolation dust effect.(3)Through numerical simulation to slit-jet that on various different working parameters, got the following good working parameters of dust-isolation slit-jet: export width is about 6mm, export angle on 10°is quite reasonable, slit jet wind supply of 7m/s is quite reasonable. ( 4) Made several modes of the similarity model experiment on slit-jet dust-isolation, and made further investigation on the influence of dust-isolation effect caused by slit-jet working parameters. Summery law of the experiments result and conclusion of the numerical simulation get very good match.更多还原