采煤工作面分区域冷负荷计算及喷雾降温技术研究

发布时间：2018-03-23 04:36

本文选题：采煤工作面　切入点：热害　出处：《中国矿业大学》2017年硕士论文　论文类型：学位论文

【摘要】：按照可再生能源发展的情况预测,在低碳和强化低碳情景下,煤炭消费比重虽有所下降,但未来几十年内仍然在我国能源结构中占据重要地位。目前,煤矿的开采深度在不断增加,热害矿井数量也在不断增多,热害将制约煤炭行业的发展。在高温矿井热害治理中,采煤工作面降温冷负荷的确定是高温矿井热害治理的基础,决定了高温矿井降温效果,合理准确的计算矿井采煤工作面冷负荷以及探讨有效地矿井降温技术是热害治理的关键因素。目前,矿井冷负荷的计算方法,都未能达到较为准确地计算采煤工作面实际冷负荷,很难满足井下降温需要,计算结果小于实际值。而且矿井降温一般均采用冷却风流降温,则存在空气载冷量不足等问题。本文围绕采煤工作面围岩的传热特性,以流体热力学、传热传质理论以及CFD数值模拟等手段,研究矿井冷负荷计算理论、采煤工作面非线性风温预测理论,建立了采煤工作面的分区域冷负荷计算法,并对采煤工作面喷雾降温技术进行探讨。论文研究的主要内容:(1)分析井下风流与围岩煤壁的热湿交换特性,并结合常用的线性风温预测方法,对矿井冷负荷的计算方法进行研究,分析矿井热害治理效果不佳的影响因素。研究得出采用风流温度均值化、线性化计算的围岩传热量小于采用非线性风温变化计算的结果,而且在目前所采用的冷负荷计算方法中冷负荷计算值均小于矿井采煤工作面的实际冷负荷。(2)分析由非线性风温计算公式预测采煤工作面风温值,研究建立将风流温度小于30℃的长度范围(35)x作为降温的有效区域,对采煤工作面分区域划分,建立分区域计算采煤工作面冷负荷的方法,计算矿井冷负荷及冷风最大载冷能力,分析采煤工作面风流入口风温、围岩温度、风流速度对采煤工作面分区域冷负荷的影响,分析得到:①目前采用的冷负荷计算法得到的冷负荷远小于分区域冷负荷计算值,其主要原因是围岩传热量采用的计算方法不同。另外,矿井降温采用冷风流的最大载冷量小于矿井降温实际冷负荷值,在热害较严重的矿井,冷风载冷量仅能满足采煤工作面入口的局部区域,为有效降温区域。②冷风流在采煤工作面入口的风温在19℃~25℃时,采煤工作面冷负荷基本不变,即冷风入口风温对高温矿井冷负荷影响较小;③对于围岩温度不同的矿井,围岩温度越高,采煤工作面冷负荷越大,其有效降温区域的长度与围岩壁温呈线性减小的关系;④在相同壁温的矿井,采煤工作面冷负荷随风速的增加而增加,且近似呈线性关系,降温区域长度和风速呈线性增加的关系;壁温增加、风速增加的情况下,有效降温区域长度增加幅度减小。(3)在数值模拟分析中,采用较低的流动雷诺数分析矿井围岩与风流近壁面换热特性,进行湍流流动近壁面的模型处理,进行数值模拟计算采煤工作面区域冷负荷,并与理论计算的采煤工作面分区域冷负荷进行对比分析,得到:①数值模拟和理论计算结果稍有差别,但整体结果较为贴合;②在采煤工作面入口后的一段距离内,围岩传热对冷风流核心区域温度影响较小,符合实际热交换热情况,模拟分析得到:入口区域冷风流温度场与理论计算的差别。(4)研究采煤工作面降温技术,当采用冷却风流降温时,由于《煤矿安全规程》对风流风速和风温的要求,使矿井风流载冷量受到限制,只能解决一段区域内的降温要求,因此本课题研究提出分区域降温的思路:利用喷水雾化供冷,分区域供给采煤工作面风流冷量的降温技术,并对喷雾降温技术进行设计研究,探讨喷雾降温技术的特性及应用。
[Abstract]:According to the prediction of the development of renewable energy, low carbon and enhanced low carbon scenario, the proportion of coal consumption has decreased, but still within the next few decades in China's energy structure occupies an important position. At present, the coal mining depth increasing, the heat harm mine in increasing the number, the heat damage will restrict the development of the coal industry. In the high temperature mine heat harm control in coal face cooling to determine the cooling load is the basis of governance in high temperature mine heat damage, determines the cooling effect of high temperature mine work, calculation of mine coal face reasonable cooling load and explore effective mine cooling technology is a key factor for heat harm treatment. At present and the calculation method of mine cooling load, have failed to achieve more accurate calculation of the actual cooling load of coal face, it is difficult to meet the needs of underground cooling. The calculation result is less than the actual value. And mine cooling general Use of cooling air cooling, there is the problem of air containing cold and other issues. In this paper, the heat transfer characteristics of surrounding rock around coal face, with fluid thermodynamics, heat transfer theory and CFD numerical simulation, theoretical calculation of mine cooling load prediction theory of coal face nonlinear wind temperature, established the calculation method of cooling load domain partition coal face and the coal face spray cooling technology is discussed. The main contents of this dissertation are: (1) analysis of the airflow and the surrounding rock of coal wall heat and moisture exchange characteristics, combined with the commonly used linear air temperature prediction method, studying the calculation method of mine cooling load, influencing factors and ineffective governance analysis mine heat. The results of the mean air temperature, the linear calculation of surrounding rock heat transfer is less than the nonlinear wind temperature calculation results, and used in the cold The cooling load calculation method of load calculation value was less than the actual mining working face of mine cooling load. (2) by the analysis of nonlinear wind temperature prediction of coal face wind temperature value, on the basis of the airflow temperature less than 30 DEG C length range (35) x as effective regional cooling, to face regional division methods, the establishment of sub regional coal face cooling load calculation, the calculation of the maximum load capacity of the mine cooling load and cold wind, analysis of coal face air entrance air temperature, the temperature of surrounding rock, analysis of effects of airflow velocity on the coal face regional cooling load: cold load method is far less than the regional cooling load calculation calculation of cooling load of currently used, the main reason is the different calculation methods of surrounding rock by heat transfer. In addition, mine cooling using cold air cooling capacity is less than the maximum load of mine temperature drop the actual cooling load value, In heat harmful mine seriously, wind load cooling capacity can only meet the local entrance of coal face, effective cooling area. The cold air at the entrance of the mining coal working surface air temperature at 19 DEG ~25 DEG, coal face cooling load is basically unchanged, namely the cold air entrance wind temperature has little effect on the high temperature mine well, for mine cooling load; the temperature of surrounding rock in different surrounding rock, the higher the temperature is, the greater the coalface cooling load, the effective cooling area and the length of the rock wall temperature decreases linearly; the mine in the same wall temperature, increase the cooling load of coal face with wind speed increasing, and approximately linear relationship between linearly increase the cooling area length and wind speed; the wall temperature increases, the wind speed increased, the effective cooling area length decrease increase. (3) in the analysis of numerical simulation, the flow of the lower Reynolds number of mine rock and wind The flow near the wall of the heat transfer characteristics of turbulent flow near the wall model, numerical simulation of regional coal face cooling load, coal face and theoretical calculation of regional cooling load were analyzed by the numerical simulation and theoretical calculation results slightly, but the overall results are close to each other; II. At the entrance of coal working face after a certain distance, the rock heat transfer of cold airflow affected core region temperature, heat exchange heat in line with the actual situation, simulation analysis: Calculation of cold airflow temperature field and the theory of entrance difference. (4) cooling technology of coal face, when the cooling air cooling, because "coal Mine Safety Regulations > requirements on the airflow temperature and velocity, the mine air containing cold quantity is limited, can only solve the area of the cooling requirements, so this research put forward the idea of regional cooling: The spray cooling technology is applied to provide the cooling technology of the airflow cooling capacity of the coal face, and the spray cooling technology is designed and researched, and the characteristics and application of the spray cooling technology are discussed.

【学位授予单位】：中国矿业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TD727.2

【参考文献】