【作者】 刘冠男；

【导师】 高峰；

【作者基本信息】 中国矿业大学 ， 工程力学， 2010， 博士

【摘要】 煤炭是我国的主体能源,在我国一次能源生产和消费结构中的比重分别占76%和69%,但是我国52%以上的煤炭资源埋深达超过1000m,采深大于800m深的矿井,热害问题不解决,就不能正常生产。我国煤炭资源开采已转向深部,而且约92%的煤炭生产是井工开采,随着采掘深度的不断增大与煤矿机械化程度的提高,矿井热害日益严重,对煤矿安全高效生产产生严重影响,成为煤炭行业亟待解决的重大课题。要进行深部煤炭资源开采,必须解决高温高湿的热环境问题,但是这方面研究仍然属于起步阶段,没有形成公认的理论体系,实施工程降温也无有效的理论与技术指导。本论文通过现场实测、热力学和流体动力学理论分析以及CFD数值模拟等手段,系统研究了煤矿回采工作面的主要热源及散热机理、回采面风温预测、回采面高温区温度场、流场分布特征和入口风流热力学状态对回采面热环境的影响,以及工作面喷淋雾化降温优化分析等关键问题,研究结果对高温矿井热害治理具有一定的指导意义。论文的主要成果与创新点如下:(1)运用工程热力学与传热学理论分析了回采工作面热源类型、散热机理及分布特征。计算结果表明围岩散热、机电设备散热和氧化散热为回采面的主要热源,其中围岩散热量和机电设备散热量一般约占回采面总放热量的70%以上。(2)以渗流力学与传热学理论为基础,将采空区散热分为采空区漏风散热、边界对流与氧化散热三部分,提出了求解回采面采空区散热量的解析表达式,为巷道风温预测提供了理论依据。(3)建立了回采面风流与温度耦合场分析的数值求解模型,提出了适用于巷道管流流动的单交错网格数值算法。该方法在求解精度上高于同位网格离散解法,在程序编制和计算时间上优于交错网格。(4)回采面计算流体动力学分析表明,工作面进风、回风隅角处流场形成涡旋,从而增大了风流与热源对流换热时间,并且由于工作面散热量大,回风隅角成为回采面的局部高温区,是热害治理的关键区域。入口风速对回采面热环境影响较大。随着入口风速的增大,工作面高温区域的范围逐渐缩小,温度呈近似线性规律降低。但存在某一临界风速,当风速大小超过临界值时,风速加大对回采面温度场的影响趋弱。(5)利用多相流理论对回采面雾化降温效果进行数值模拟。结果表明,输冷量不变时,喷射角与初始粒径过大会对回采面降温起到抑制作用,雾滴初速度应存在一临界值,当初速度高于临界值时,降温效率逐渐趋于稳定。回采面出口风温随回采面入口处风流相对湿度的增大呈幂函数规律升高。(6)在不增加回采面通风量与制冷量的前提下,对工作面雾化降温进行了优化分析,通过改变雾化液滴的初始热力学参数(速度、液滴大小、喷射角),可使回风隅角温度降低5%左右。更多还原

【Abstract】 Coal is the main energy sources in our country.The proportion of production and consumption of primary energy in our country is about 76% and 69%.But more than 52% coal resource is in the depth of more than 1000m.Regular production could not be proceeded,while heat damage exists,if the depth is more than 800m.The exploitation of coal resource has turning to deep interior in our country,and about 92% of the production is in mine well.With the decreasing of the reserves of fleet coal bed and the increasing of the mechanization degree, heat damage becomes more and more serious.and influents the safety and high effeciency of coal production more and more heavily.Heat damage has become a significant issue needs to be solved.The hot environment with hign temperature and high humidity should be solved,in order to explore coal mine in deep interior.But the study on this area is still in the primary stage.There is no recognized theory system and effective instruction of technology and theory.Parameter measurement in coal mine,energetics and hydrokinetics analysis and CFD simulation are used to investigate the main heat sources,the mechanism of heat emanating, temperature forecasting of robbing working face,The characteristic of the flow field and the temperature field of robbing working face, and the optimization design of the cooling efficiency.The research results have guidance meaning for coal mine heat damage control. The main conclusions and innovate points of the study are as follows:(1) The mechanism of heat emanating and the distribution of heat sources were analyzed by thermodynamics and heat transfer theory.The results shows that heat from wall rock,machines and oxidation are the main heat sources in robbing working face.The amount of heat from wall rock and machines is more than 70% of all of the heat sources.(2) Heat from gob area was treated as three parts:heat from air leak,convection at the boundary and heat from oxidation.Resolution expression was represented for calculating the amount of heat emanating at robbing working face more precisely,based on seep mechanics and heat transfer theory.(3) The numerical solution model which coupled the flow field and the temperature field of robbing working face,and a single stagger grid arithmetic which is suitable for pipe flow as laneway were represented.The arithmetic is better than collocated grid method at precision and better than stagger grid method at programming and calculating time.(4) The CFD simulation results shows that,eddies were formed at the inlet corner and the outlet corner,so that the convection heat transfer time between air and the heat sources increased.The outlet corner came to be a local high temperature region,because of the large amount of heat emanated from the working face. The hot environment of robbing working face is heavily influenced by the inlet velocity.With the increase of the inlet velocity,the area of high temperature region in robbing working face reduced,and the temperature reduced linearity.There is a critical velocity of air.If the velocity is higher than the critical value, the heat environment could not be effectively improved by increasing inlet velocity.(5) The atomization cooling effect was forecased by multiphase theory.The simulation results shows that,if the quantity of cold water is steady,too big spray angle and diameter of the fogdrop would restrain the cooling efficiency.There is a critical value of the initial velocity of fogdrop.If the initial velocity is higher than the critical value,the cooling efficiency tends to be steady.The temperature of outlet increased in a power function with the accretion of the humidity of the airflow at inlet.(6) The initial thermodynamic parameters of fogdrop(velocity,diameter and spray angle) of the cooling project at robbing working face were optimized.After optimizing,the temperature of the outlet corner reduced about 5%.更多还原