本文關(guān)鍵詞： 低溫氧化 多場耦合 非均質(zhì)孔隙率 采空區(qū) 四維動態(tài)　出處：《北京科技大學(xué)》2017年博士論文　論文類型：學(xué)位論文

【摘要】：采空區(qū)遺煤自燃是煤礦災(zāi)害的主要來源之一,嚴(yán)重威脅著煤礦的安全生產(chǎn)。本文基于煤氧化學(xué)動力學(xué)機(jī)理及多孔介質(zhì)滲流理論,對采空區(qū)在動態(tài)推進(jìn)過程中遺煤氧化升溫的時空演化規(guī)律進(jìn)行研究,為實(shí)際生產(chǎn)及煤礦自燃靶向性防治提供依據(jù)。本文在移動雙坐標(biāo)系的基礎(chǔ)上,建立了采空區(qū)氧化升溫時空演化動態(tài)模型,主要包括基于煤氧化學(xué)動力學(xué)原理的煤氧反應(yīng)動力學(xué)模型和多場耦合模型、非均質(zhì)孔隙率時空演化模型。通過Fluent開源接口UDF將模型編入Fluent中對已有控制方程進(jìn)行補(bǔ)充和修正,對陽泉煤業(yè)孫家溝礦13304工作面采空區(qū)升溫規(guī)律進(jìn)行了四維動態(tài)模擬研究。通過相似準(zhǔn)則的推導(dǎo),搭建了動態(tài)采空區(qū)實(shí)驗(yàn)臺,對模型做進(jìn)一步的研究和驗(yàn)證,采用分體式開采系統(tǒng)實(shí)現(xiàn)工作面的動態(tài)推進(jìn)，研制了一種自發(fā)熱材料,與煤混合后做為相似材料以非均質(zhì)的方式填充在采空區(qū)內(nèi),采用48路溫度巡檢儀進(jìn)行密集采集數(shù)據(jù),對動態(tài)采空區(qū)升溫過程進(jìn)行了實(shí)驗(yàn)研究。研究表明：通過四維動態(tài)模擬研究,得到了采空區(qū)溫度場在工作面推進(jìn)過程中的變化規(guī)律,主要包括溫度場的分布規(guī)律、升溫規(guī)律、高溫點(diǎn)的遷移規(guī)律、升溫—耗氧之間的耦合關(guān)系等。高溫區(qū)域主要在進(jìn)風(fēng)側(cè),隨著工作面的推進(jìn),高溫區(qū)域不斷向前遷移,遷移速度主要受到孔隙率、工作面推進(jìn)速度及開采時間的影響；對采空區(qū)氧化升溫之間的耦合關(guān)系進(jìn)行研究,揭示了采空區(qū)內(nèi)高溫區(qū)與高氧區(qū)之間的動態(tài)變化規(guī)律，高溫區(qū)始終位于高氧區(qū)之后,二者的背離程度越大,進(jìn)入降溫區(qū)時剩余氧量越多,對自燃的削弱程度越大；從多場耦合的角度,對比分析了U型通風(fēng)與U+L型通風(fēng)采空區(qū)遺煤的氧化過程，，表明尾巷的存在使得氧化升溫帶寬度增加且向回風(fēng)側(cè)偏移,回風(fēng)側(cè)在聯(lián)絡(luò)巷口溫度高出周圍約3.3℃,聯(lián)絡(luò)巷口具有很好的升溫潛質(zhì),確定了尾巷對采空區(qū)自燃的危害性。通過在實(shí)驗(yàn)室搭建動態(tài)采空區(qū)氧化升溫實(shí)驗(yàn),對采空區(qū)時空演化動態(tài)模型進(jìn)行驗(yàn)證。研制出了一種能在室溫下形成明顯溫度場的自發(fā)熱材料,通過試管實(shí)驗(yàn)及傳熱相似性實(shí)驗(yàn),得到了相似材料的最佳配比；相似材料與原煤的放熱量相似比qr=4.5,耗氧速率相似比V(T)r=120,實(shí)驗(yàn)中時間相似比為tr=1/100。對工作面推進(jìn)過程中的溫度場進(jìn)行研究,表明無論是溫度場的分布、升溫速率都與數(shù)值模擬結(jié)果基本吻合。通過束管監(jiān)測的方式在采空區(qū)進(jìn)風(fēng)側(cè)和回風(fēng)側(cè)預(yù)埋測點(diǎn)，進(jìn)行了現(xiàn)場測溫試驗(yàn)。根據(jù)特征點(diǎn)升溫規(guī)律的實(shí)測值和模擬值對比分析結(jié)果,表明模擬結(jié)果與實(shí)測結(jié)果具有一致性。從而為確定采空區(qū)高溫區(qū)域的參數(shù)及采空區(qū)遺煤自燃的預(yù)測提供依據(jù)。
[Abstract]:The spontaneous combustion of coal in goaf is one of the main sources of coal mine disasters, which seriously threatens the safety of coal production. This paper is based on the kinetic mechanism of coal oxidation and porous media seepage theory. The temporal and spatial evolution law of coal oxidation and heating in goaf during dynamic advance is studied, which provides the basis for actual production and prevention and control of coal spontaneous combustion. This paper is based on moving double coordinate system. The spatio-temporal evolution dynamic model of oxidation heating in goaf is established, which includes coal oxygen reaction kinetic model and multi-field coupling model based on coal oxidation kinetics principle. The model of spatiotemporal evolution of heterogeneous porosity is programmed into Fluent by UDF, an open source interface of Fluent, to supplement and modify the existing governing equations. In this paper, the four dimensional dynamic simulation study on the heating law of goaf in 13304 working face of Sunjiagou Coal Mine, Yangquan Coal Industry is carried out. Through the derivation of similar criteria, a dynamic goaf experimental bench is built, and the model is further studied and verified. In this paper, a self-heating material is developed, which is mixed with coal and filled in the goaf in a heterogeneous way after mixing with coal, and 48 channel temperature patrol instrument is used to collect the data. The experimental study on the process of dynamic goaf temperature rise is carried out. The results show that through the four dimensional dynamic simulation study, the variation law of the temperature field in the working face is obtained, which includes the distribution law of temperature field and the law of heating up. The migration law of high temperature points and the coupling relationship between temperature rise and oxygen consumption etc. The high temperature area is mainly in the inlet air side. With the advance of the working face, the high temperature area moves forward continuously, and the migration velocity is mainly affected by porosity. The influence of working face speed and mining time on the coupling relationship between oxidation and temperature rise in goaf is studied, and the dynamic change law between high temperature area and high oxygen area in goaf is revealed. The high temperature area is always located behind high oxygen area. The greater the degree of deviation between the two is, the more oxygen is left in the cooling zone, and the greater the degree of weakening to spontaneous combustion. From the point of view of multi-field coupling, the oxidation process of coal left in goaf of U-type ventilation and UL-type ventilation is compared and analyzed. The results showed that the width of the oxidation heating zone increased and the return wind side shifted to the return wind side. The temperature of the back wind side was about 3.3 鈩

本文編號：1549950