煤与瓦斯突出能量分析及其物理模拟的相似性研究

发布时间：2018-03-17 05:23

本文选题：煤与瓦斯突出　切入点：能量机制　出处：《山东大学》2017年博士论文　论文类型：学位论文

【摘要】：煤炭是我国的主体能源,2015年,煤炭在一次性能源消费结构中的比重约为64%,并且在相当长时期内,煤炭的主体能源地位不会变化。我国煤炭开采条件复杂,特别是煤与瓦斯突出事故无论在事故发生起数和死亡人数上都处在煤矿事故的前列,煤与瓦斯突出已成为煤炭安全生产的挑战性难题。加强对煤与瓦斯突出机理的研究,发现突出的影响因素、产生条件和发展过程,有利于加深对突出的认识。加强对煤与瓦斯突出物理模拟的相似性研究有利于从相似模拟试验角度研究突出机理与规律。本文对型煤试件的煤体弹性能、瓦斯膨胀能进行了实验室实测分析,得出了型煤试件变形破坏过程中的能量变化规律;对煤与瓦斯突出的煤体弹性能、瓦斯膨胀能等主要潜能和煤体破碎功、抛出功等主要耗能进行了理论分析,构建了能量方程,分析了突出的主要能量来源;本文分析了相似准则的建立方法和难点,开展了煤与瓦斯突出物理模拟相似准则研究;在相似准则的指导下,研制了煤岩相似材料和瓦斯相似气体,满足"固-气"耦合模拟试验需求;分析了当前煤与瓦斯突出模拟试验仪器的优势和不足,研发了大型相似模拟试验仪器。研究获得的结论主要体现在以下几个方面。(1)型煤试件在单轴压缩下发生能量交换,输入的总能量有一部分转换为弹性能,峰值强度附近弹性能达到最大,占总能量输入的70%左右,峰值强度后弹性能迅速释放。型煤试件的瓦斯膨胀能在峰值强度以前变化不大,峰值强度时骤然增大25%以上,引起突出潜能的突变。(2)煤体弹性能、瓦斯膨胀能是突出的主要能量,煤体破碎功和抛出功是能量的主要耗散方式。得出了突出潜能和突出耗能的计算方法,并得出了符合量纲和谐原理的煤与瓦斯突出能量方程。开展了能量方程的数值解算,得出瓦斯膨胀能是突出的最主要能量,比煤体弹性能大一个数量级以上。(3)基于能量方程推导得出了相似准则,得到了容重、孔隙率、吸附性、弹性模量、泊松比、内聚力、内摩擦角等参数关系的相似准数。根据相似准数得出了一组方便实用的相似比尺。(4)腐植酸钠水溶液作为煤岩相似材料胶结剂基本不改变煤体吸附性,且胶结剂浓度能够调节相似材料的强度性质,15MPa下相似材料容重、孔隙率与原煤比较一致。该相似材料十分切合煤体的物理力学特性和相似准则要求。不同浓度配比的CO2+N2二元混合气体作为甲烷气体的相似气体十分理想,并且相似度和安全性更高。(5)构建了以模型反力与密封单元、地应力加载与控制单元、瓦斯气体加载与控制单元、微型巷道掘进与控制单元、多物理量信息获取单元为主要模块的大型煤与瓦斯突出相似模拟试验装置。研制的试验仪器模型空间合理、真三维加载、密封能力高,实现了模拟巷道开挖功能,且更加自动化、信息化和安全化。
[Abstract]:Coal is the main source of energy in our country. In 2015, the proportion of coal in the disposable energy consumption structure was about 64%, and in a long period of time, the main energy status of coal will not change. In particular, coal and gas outburst accidents are in the forefront of coal mine accidents in both the number of accidents and the number of deaths. Coal and gas outburst has become a challenging problem in coal production safety. Discover prominent influencing factors, production conditions and development processes, Strengthening the similarity study of physical simulation of coal and gas outburst is beneficial to the study of outburst mechanism and law from the angle of similarity simulation test. The gas expansion energy is measured and analyzed in laboratory, and the energy change law during deformation and failure of briquette specimen is obtained, and the main potential of coal and gas outburst, such as coal body elasticity energy, gas expansion energy, and coal body breaking work, are obtained. The main energy consumption such as throwing work is analyzed theoretically, the energy equation is constructed, the main energy sources of outburst are analyzed, the methods and difficulties of establishing similarity criterion are analyzed, and the similarity criterion of physical simulation of coal and gas outburst is studied. Under the guidance of similarity criterion, similar materials of coal and rock and similar gas of gas are developed to meet the needs of "solid-gas" coupling simulation test, and the advantages and disadvantages of the current simulation test instrument for coal and gas outburst are analyzed. A large scale similar simulation test instrument has been developed. The main conclusions of the study are as follows: (1) the energy exchange occurs in uniaxial compression of coal samples, and part of the total input energy is converted into elastic energy. The elastic energy near the peak intensity reaches the maximum, accounting for about 70% of the total energy input. After the peak strength, the elastic energy can be released rapidly. The gas expansion energy of the briquette sample does not change much before the peak strength, but increases suddenly over 25% at the peak strength. The energy of gas expansion is the main energy of outburst, and the crushing and ejecting work of coal body are the main dissipation modes of energy. The calculation method of outburst potential and outburst energy is obtained. The energy equation of coal and gas outburst is obtained in accordance with the dimensional harmony principle. The numerical solution of the energy equation is carried out, and the gas expansion energy is the main outburst energy. Based on the energy equation, the similarity criteria are derived, such as bulk density, porosity, adsorption, modulus of elasticity, Poisson's ratio, cohesion, etc. According to the similarity criterion, a group of convenient and practical similar scale. 4) Sodium humate solution as cementing agent of similar material of coal and rock can not change the adsorbability of coal body. And the concentration of binder can adjust the strength property of the similar material and the bulk density of the similar material under 15MPa. The porosity is consistent with that of raw coal. The similar material is very suitable for the physical and mechanical properties of coal and the requirement of similarity criterion. The binary mixture of CO2 N2 with different concentrations is ideal as the similar gas of methane gas. The model reaction and sealing unit, the in-situ stress loading and control unit, the gas loading and controlling unit, the micro roadway driving and controlling unit are constructed. A large scale simulation test device for simulating coal and gas outburst with the main module of multi-physical quantity information acquisition unit is developed. The model space of the developed test instrument is reasonable, the true three-dimensional loading, the sealing ability is high, and the excavation function of simulated roadway is realized. And more automation, information and security.
【学位授予单位】：山东大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：TD713

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