煤升温过程中的声发射电磁辐射研究

发布时间：2018-08-18 07:41

【摘要】：我国矿井火灾十分严重,威胁着广大矿工的生命安全,浪费了大量的煤炭资源,因此预测预防矿井火灾越显突出。如何能有效的探测火灾的发生和定位火源的位置仍然是急需深入研究的问题。地球物理法在煤样动力灾害中已经得到广泛的应用,因此研究煤样升温过程中是否存在声发射和电磁辐射的变化规律,对火灾探测的意义非常重大。本文采用煤样升温变形破坏声电效应实验系统,测试了不同试样(煤样、岩样)在加热破裂时的声发射、电磁辐射信号：对比分析了煤样在升温过程中声发射和电磁辐射信号的特征规律；研究了不同频率下煤样声发射、电磁辐射信号变化规律,测试了同一频率不同位置电磁辐射变化规律。研究表明,煤样、岩样在加热升温过程中均会产生声发射和电磁辐射信号,煤样在加热升温的整个过程中所产生的声发射先增大后减小,电磁辐射信号随着温度的升高不断增大,随着温度的减小信号的强度也在减小,变化趋势和温度基本一致；煤样声发射、电磁辐射与煤样孔隙结构和裂纹有着密切的关系,而且与煤样燃烧的不同阶段密切相关,具有明显的阶段分布特征；不同频率的天线接收到的电磁辐射信号有基本一致的,但也存在差异；空间不同位置都存在电磁辐射信号,随着距离增大,干扰增大。根据以上的特性,可以准确预测火灾隐患以及火灾发生的位置,对于煤矿火灾安全有重要的意义。
[Abstract]:The mine fire in China is very serious, which threatens the lives of the majority of miners and wastes a lot of coal resources, so it is more and more prominent to predict and prevent the mine fire. How to effectively detect the occurrence of fire and locate the location of fire source is still an urgent problem. Geophysical method has been widely used in coal dynamic disasters, so it is very important to study whether there are acoustic emission and electromagnetic radiation in the process of coal sample heating. In this paper, the acoustic emission of different samples (coal samples and rock samples) during heating rupture is measured by using the experimental system of acoustoelectric effect of heating deformation and failure of coal samples. Electromagnetic radiation signal: the characteristic law of acoustic emission and electromagnetic radiation signal of coal sample in the process of heating up is compared and analyzed, and the variation law of acoustic emission signal and electromagnetic radiation signal of coal sample under different frequency is studied. The variation rule of electromagnetic radiation at the same frequency and different position was measured. The results show that the acoustic emission and electromagnetic radiation signal are produced in the heating process of coal sample and rock sample, and the acoustic emission of coal sample increases first and then decreases during the whole process of heating up. The electromagnetic radiation signal increases with the increase of temperature, and the intensity of the signal decreases with the decrease of temperature, and the variation trend is basically consistent with the temperature, the acoustic emission and electromagnetic radiation of coal sample have a close relationship with the pore structure and crack of coal sample. Moreover, it is closely related to the different stages of coal combustion and has obvious phase distribution characteristics; the electromagnetic radiation signals received by antennas with different frequencies are basically the same, but there are also differences; there are electromagnetic radiation signals at different locations in space. As the distance increases, the interference increases. According to the above characteristics, the hidden fire hazard and the location of the fire can be accurately predicted, which is of great significance to the safety of coal mine fire.
【学位授予单位】：辽宁工程技术大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：TD752

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