基于区域地温场的煤矿床温度场数值模拟研究
发布时间：2018-08-12 17:22
【摘要】：高温热害和矿井火灾问题一直是煤矿安全生产的重大威胁,国内外众多学者对热害问题和煤自燃进行了大量研究并提出相应的防治措施,但是相关事故仍经常发生。煤矿开采深度的逐年增加,会导致井下开采时风流温度过高,一方面造成工人身心健康严重受损,一方面使得矿井事故发生率剧增。因此,本文结合大尺度地温场,采用FORTRAN自主编程,对深层煤矿床温度场进行了模拟研究。首先,依据热传递方程和渗流方程,本文建立了基于区域地温场的二维煤矿床温度场数学模型,并根据Galerkin法推导出了有限单元法计算的基本方程。在此基础上,运用FORTRAN语言编制了二维煤矿床温度场的数值模拟计算程序,程序包括网格剖分、异常区域圈定、构建系数矩阵、边界条件确定、温度场求解等部分。其次,引用公开出版文献报道的实测数据与计算结果,对本文所建数学模型进行了验证,模拟计算结果与文献报道数据均具有较好的一致性,表明本模型适用于地温场和采动影响下的煤矿床温度场分析。在第一个算例中,参照波兰新鲁达煤矿的实测数据,综合考虑了研究区域的地质结构和地表起伏情况；并设定等温异常区,运用所建数学模型在不考虑流体流动的条件下计算了废弃矿井周围地层温度场分布。在第二个算例中,本文对某区域尺度系统的地下水盆地渗流热效应进行模拟计算。根据岩层渗透率大小将地下水盆地热系统分成传导型换热和对流型换热,计算不同渗透率下受渗流影响的地下水盆地热分布状态。最后,本文将地温场研究中异常区的处理方法引入到煤矿床温度场研究中,即将开采工作面与采空区视为介质异常区,采用自主编写的FORTRAN程序对风流影响下的煤矿床温度场分布规律进行了模拟分析。在不考虑煤自热氧化的情况下,由于地温场的作用,在工作面前半段风流温度梯度较大,沿风流流动方向,温度逐渐升高；而工作面后半段,温度梯度逐渐减小。而采空区内的漏风现象对温度场影响较弱,地热热流的影响为主导因素,造成采空区热量积聚,温度升高。对于深部煤层开采,在地热效应显著的情况下,工作面温度极易超过《煤矿安全规程》规定的26℃,不能满足煤矿安全生产的要求。本文获得的研究结果可以为矿井降温以及制定采空区自然发火的预防措施提供参考。
[Abstract]:High temperature thermal damage and mine fire have been a major threat to the safety of coal production. Many scholars at home and abroad have done a lot of research on thermal damage and spontaneous combustion of coal and put forward corresponding prevention measures, but the related accidents still occur frequently. The increase of coal mining depth year by year will lead to the high temperature of air flow in underground mining. On the one hand, it will cause serious damage to workers' physical and mental health, on the other hand, the occurrence rate of mine accidents will increase dramatically. Therefore, in this paper, the temperature field of deep coal bed is simulated and studied by using FORTRAN independent programming combined with large scale ground temperature field. Firstly, according to the heat transfer equation and seepage equation, the mathematical model of two-dimensional coal bed temperature field based on regional geothermal field is established, and the basic equation of finite element method is derived according to Galerkin method. On this basis, a numerical simulation program of two-dimensional coal bed temperature field is compiled by using FORTRAN language. The program includes grid generation, abnormal area delineation, coefficient matrix construction, boundary condition determination, temperature field solution and so on. Secondly, the mathematical model established in this paper is verified by using the measured data and calculation results reported in the published literature, and the simulation results are in good agreement with the data reported in the literature. It shows that this model is suitable for the analysis of coal bed temperature field under the influence of ground temperature field and mining movement. In the first example, the geological structure and surface fluctuation of the studied area are considered synthetically according to the measured data of the New Luda Coal Mine in Poland, and the isothermal anomalous zone is set up. The temperature field distribution around the abandoned mine is calculated by using the established mathematical model without considering the fluid flow. In the second example, the seepage thermal effect of groundwater basin in a regional scale system is simulated and calculated. The thermal system of groundwater basin is divided into conduction heat transfer and flow heat transfer according to the permeability of rock bed, and the heat distribution of groundwater basin affected by seepage under different permeability is calculated. Finally, this paper introduces the treatment method of abnormal area in the study of geothermal field into the study of temperature field of coal mine bed, that is, the mining face and goaf are regarded as abnormal medium areas. The distribution law of coal bed temperature field under the influence of air flow is simulated and analyzed by FORTRAN program. In the case of coal autothermal oxidation, because of the effect of the geothermal field, the temperature gradient of the air flow in the half section before work is larger, and the temperature increases gradually along the direction of the air flow, while in the second half of the working face, the temperature gradient decreases gradually. But the air leakage in goaf has a weak effect on the temperature field, and the influence of geothermal heat flow is the leading factor, which results in the heat accumulation and temperature rising in the goaf. For deep coal seam mining, when the geothermal effect is significant, the working face temperature is easily higher than the 26 鈩，
本文编号：2179755
[Abstract]:High temperature thermal damage and mine fire have been a major threat to the safety of coal production. Many scholars at home and abroad have done a lot of research on thermal damage and spontaneous combustion of coal and put forward corresponding prevention measures, but the related accidents still occur frequently. The increase of coal mining depth year by year will lead to the high temperature of air flow in underground mining. On the one hand, it will cause serious damage to workers' physical and mental health, on the other hand, the occurrence rate of mine accidents will increase dramatically. Therefore, in this paper, the temperature field of deep coal bed is simulated and studied by using FORTRAN independent programming combined with large scale ground temperature field. Firstly, according to the heat transfer equation and seepage equation, the mathematical model of two-dimensional coal bed temperature field based on regional geothermal field is established, and the basic equation of finite element method is derived according to Galerkin method. On this basis, a numerical simulation program of two-dimensional coal bed temperature field is compiled by using FORTRAN language. The program includes grid generation, abnormal area delineation, coefficient matrix construction, boundary condition determination, temperature field solution and so on. Secondly, the mathematical model established in this paper is verified by using the measured data and calculation results reported in the published literature, and the simulation results are in good agreement with the data reported in the literature. It shows that this model is suitable for the analysis of coal bed temperature field under the influence of ground temperature field and mining movement. In the first example, the geological structure and surface fluctuation of the studied area are considered synthetically according to the measured data of the New Luda Coal Mine in Poland, and the isothermal anomalous zone is set up. The temperature field distribution around the abandoned mine is calculated by using the established mathematical model without considering the fluid flow. In the second example, the seepage thermal effect of groundwater basin in a regional scale system is simulated and calculated. The thermal system of groundwater basin is divided into conduction heat transfer and flow heat transfer according to the permeability of rock bed, and the heat distribution of groundwater basin affected by seepage under different permeability is calculated. Finally, this paper introduces the treatment method of abnormal area in the study of geothermal field into the study of temperature field of coal mine bed, that is, the mining face and goaf are regarded as abnormal medium areas. The distribution law of coal bed temperature field under the influence of air flow is simulated and analyzed by FORTRAN program. In the case of coal autothermal oxidation, because of the effect of the geothermal field, the temperature gradient of the air flow in the half section before work is larger, and the temperature increases gradually along the direction of the air flow, while in the second half of the working face, the temperature gradient decreases gradually. But the air leakage in goaf has a weak effect on the temperature field, and the influence of geothermal heat flow is the leading factor, which results in the heat accumulation and temperature rising in the goaf. For deep coal seam mining, when the geothermal effect is significant, the working face temperature is easily higher than the 26 鈩，
本文编号：2179755
本文链接：https://www.wllwen.com/kejilunwen/kuangye/2179755.html
