本文選題：爆炸驅(qū)動 + 氣體混合　； 參考：《北京理工大學》2015年博士論文

【摘要】：甲烷爆炸或甲烷-煤塵爆炸是煤礦井下爆炸事故的主要形式，受到社會的廣泛關注。甲烷-空氣混合物、煤粉-空氣混合物的混合過程與爆炸特性是爆炸事故發(fā)生的基礎問題，因此開展此項研究工作具有重要理論意義和現(xiàn)實意義。 本文利用以大尺寸密閉容器10m3爆炸罐為主體的多元氣體混合及濃度監(jiān)測實驗系統(tǒng)；通過系統(tǒng)性實驗，研究了進氣裝置結構尺寸、進氣速率及不同進氣壓差等因素對甲烷-空氣二元混合效果的影響，結果表明，當進氣系統(tǒng)開孔直徑為1.5mm、開孔間距為100mm、進氣速率控制在8m3/h和初始真空度為-0.04MPa時，氣體混合效果達到最佳狀態(tài)。 在甲烷-空氣快速均勻混合的條件下，對大尺寸密閉容器10m3爆炸罐內(nèi)甲烷在空氣中的爆炸極限進行了測試，通過壓力發(fā)展和光學測試相結合的評判標準，按照一定程度“絕對安全”的理念，確定10m3爆炸罐內(nèi)甲烷在空氣中的不爆炸下限為5.5%，不爆炸上限為15.5%。在對甲烷空氣混合物燃爆壓力波形分析后發(fā)現(xiàn)，接近甲烷爆炸下限濃度處存在三種壓力波形式且存在前導弱壓力波和二次發(fā)展形成的燃燒波共存的狀態(tài)。 基于爆炸波驅(qū)動固體顆粒拋撒的相關理論及基礎研究成果，建立了適用于大尺寸空間內(nèi)煤粉云團均勻穩(wěn)定形成的方法。通過系統(tǒng)實驗，對爆炸波驅(qū)動煤粉拋撒的過程進行動態(tài)分析，發(fā)現(xiàn)煤塵云團邊界層速度呈現(xiàn)三個運動階段：加速、減速和湍流階段；通過分析不同驅(qū)動能量對煤粉云團的邊界速度及云團體積的影響，發(fā)現(xiàn)在本實驗條件下，中心藥量的增加并不能獲得較大的云團體積，可以獲得較大的初始邊界運動速度；當中心藥質(zhì)量百分比為1.3%時，煤粉量范圍在320g到1110g之間的拋撒形成云團體積均達到最大值。 利用AutoReaGas軟件模擬研究了巷道內(nèi)甲烷濃度、甲烷積聚區(qū)位置、障礙物阻塞比、初始壓力、初始溫度等因素對甲烷-空氣混合物爆炸特征參數(shù)的影響；對比分析了甲烷-空氣和甲烷-煤粉-空氣混合物爆炸特征參數(shù)。結果發(fā)現(xiàn)，有煤粉參與的燃燒爆炸混合物的爆炸超壓更大，，最大超壓出現(xiàn)的位置更靠近點火源。 上述取得的大尺度條件下甲烷及煤塵空氣中混合與爆炸特性研究的成果，為煤礦井下爆炸預防和控制打下了基礎。
[Abstract]:Methane explosion or methane-coal dust explosion is the main form of underground coal mine explosion, and has been widely concerned by the society.The mixing process and explosion characteristics of methane-air mixture, pulverized coal and air mixture are the basic problems of explosion accident, so it is of great theoretical and practical significance to carry out this research.In this paper, a multicomponent gas mixing and concentration monitoring system with 10m3 explosion tank as the main body is used, and the structural dimensions of the intake device are studied through systematic experiments.The effects of inlet rate and different inlet pressure difference on the effect of methane air binary mixing were studied. The results show that when the inlet system is 1.5mm in diameter and 100mm in spacing, the inlet rate is controlled at 8m3/h and initial vacuum of -0.04MPa.The gas mixing effect reaches the best condition.Under the condition of rapid and uniform mixing of methane and air, the explosion limit of methane in the 10m3 explosion tank of a large size airtight vessel was measured. The criterion of combining pressure development with optical test was adopted.According to the concept of "absolute safety" to a certain extent, the lower limit of non-explosion of methane in 10m3 explosion tank in air is 5.5 and the upper limit of non-explosion is 15.5.It is found that there are three kinds of pressure waves near the lower limit of methane explosion and the coexistence of the leading weak pressure wave and the combustion wave formed by the secondary development after the analysis of the explosion pressure waveform of the methane air mixture.Based on the theory of explosive wave driving solid particle dispersion and the basic research results, a method for uniform and stable formation of pulverized coal cloud in large space is established.Through systematic experiments, the dynamic analysis of pulverized coal dispersal driven by explosion wave is carried out. It is found that the velocity of the boundary layer of coal dust cloud presents three stages: acceleration, deceleration and turbulence;By analyzing the influence of different driving energy on the boundary velocity and cloud volume of pulverized coal cloud, it is found that under the experimental conditions, the larger cloud volume can not be obtained with the increase of the central charge, and the larger initial boundary velocity can be obtained.When the mass percentage of the central medicine is 1.3g, the volume of the cloud will reach the maximum when the amount of pulverized coal is in the range of 320g to 1110g.The effects of methane concentration, location of methane accumulation area, barrier blocking ratio, initial pressure and initial temperature on the characteristic parameters of methane / air mixture explosion were simulated by AutoReaGas software.The explosion characteristic parameters of methane-air and methane-coal-air mixtures are compared and analyzed.The results show that the explosion overpressure of the mixture with pulverized coal is higher and the location of the maximum overpressure is closer to the ignition source.The results of the study on the mixing and explosion characteristics of methane and coal dust in the air on large scale have laid a foundation for the prevention and control of underground explosion in coal mines.
【學位授予單位】：北京理工大學
【學位級別】：博士
【學位授予年份】：2015
【分類號】：TD712.7

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