發(fā)布時間：2018-08-12 17:22

【摘要】：高溫熱害和礦井火災問題一直是煤礦安全生產(chǎn)的重大威脅,國內(nèi)外眾多學者對熱害問題和煤自燃進行了大量研究并提出相應的防治措施,但是相關(guān)事故仍經(jīng)常發(fā)生。煤礦開采深度的逐年增加,會導致井下開采時風流溫度過高,一方面造成工人身心健康嚴重受損,一方面使得礦井事故發(fā)生率劇增。因此,本文結(jié)合大尺度地溫場,采用FORTRAN自主編程,對深層煤礦床溫度場進行了模擬研究。首先,依據(jù)熱傳遞方程和滲流方程,本文建立了基于區(qū)域地溫場的二維煤礦床溫度場數(shù)學模型,并根據(jù)Galerkin法推導出了有限單元法計算的基本方程。在此基礎上,運用FORTRAN語言編制了二維煤礦床溫度場的數(shù)值模擬計算程序,程序包括網(wǎng)格剖分、異常區(qū)域圈定、構(gòu)建系數(shù)矩陣、邊界條件確定、溫度場求解等部分。其次,引用公開出版文獻報道的實測數(shù)據(jù)與計算結(jié)果,對本文所建數(shù)學模型進行了驗證,模擬計算結(jié)果與文獻報道數(shù)據(jù)均具有較好的一致性,表明本模型適用于地溫場和采動影響下的煤礦床溫度場分析。在第一個算例中,參照波蘭新魯達煤礦的實測數(shù)據(jù),綜合考慮了研究區(qū)域的地質(zhì)結(jié)構(gòu)和地表起伏情況；并設定等溫異常區(qū),運用所建數(shù)學模型在不考慮流體流動的條件下計算了廢棄礦井周圍地層溫度場分布。在第二個算例中,本文對某區(qū)域尺度系統(tǒng)的地下水盆地滲流熱效應進行模擬計算。根據(jù)巖層滲透率大小將地下水盆地熱系統(tǒng)分成傳導型換熱和對流型換熱,計算不同滲透率下受滲流影響的地下水盆地熱分布狀態(tài)。最后,本文將地溫場研究中異常區(qū)的處理方法引入到煤礦床溫度場研究中,即將開采工作面與采空區(qū)視為介質(zhì)異常區(qū),采用自主編寫的FORTRAN程序?qū)︼L流影響下的煤礦床溫度場分布規(guī)律進行了模擬分析。在不考慮煤自熱氧化的情況下,由于地溫場的作用,在工作面前半段風流溫度梯度較大,沿風流流動方向,溫度逐漸升高；而工作面后半段,溫度梯度逐漸減小。而采空區(qū)內(nèi)的漏風現(xiàn)象對溫度場影響較弱,地熱熱流的影響為主導因素,造成采空區(qū)熱量積聚,溫度升高。對于深部煤層開采,在地熱效應顯著的情況下,工作面溫度極易超過《煤礦安全規(guī)程》規(guī)定的26℃,不能滿足煤礦安全生產(chǎn)的要求。本文獲得的研究結(jié)果可以為礦井降溫以及制定采空區(qū)自然發(fā)火的預防措施提供參考。
[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，

本文編號：2179755