煤自燃特性宏观表征参数及测试方法研究

发布时间：2018-04-28 17:57

本文选题：煤自燃 + 宏观表征参数　；参考：《西安科技大学》2014年博士论文

【摘要】：煤炭自燃严重威着矿井的安全生产，近年来，煤自燃特性的定量表征及危险程度的准确判定是煤矿安全领域研究的热点和难点。论文围绕煤自燃性表征参数获取方法进行研究，在煤氧吸附与自燃特性理论研究基础上，确定了煤自燃的主要宏观表征参数，自行设计建立了公斤级煤量自然发火实验装置，提出了煤自燃倾向性和自然发火期实验测试的新方法，通过对黄陵2号煤的实验测试分析，得出煤自燃宏观表征参数，确定了规范的实验条件，并与大型煤自然发火实验和程序升温实验的对比分析表明，，该实验装置综合了上述两类实验系统的优点，具有快速、准确测定煤自燃宏观表征参数的特点，为煤自燃特性和自然发火期实验测定标准制定提供了理论和实验基础。取得主要创新性成果如下：（1）基于煤的孔隙结构及煤对氧的吸附类型和热量关系，分析煤低温氧化时不同类型吸附在煤氧化自热过程中的作用，结合煤发火规律及其影响因素，运用多孔介质渗流力学和传热传质学理论及相关的数学模型，确定了煤氧化自热过程中数值计算的关键参数：煤的耗氧速度、放热强度，为煤自燃性表征参数测试方法提供了理论支持。（2）结合破碎煤体的放热和散热特性，从煤量、绝热条件、控制精度及相应软硬件等方面分析了实验要求。研究创建了公斤级煤量自然发火实验装置，装置的热量散失值能够满足煤氧化升温的条件，实现了7.1kg煤量煤自然氧化升温过程实验模拟，解决了大煤量自然发火实验工作量大，小煤量实验需外部加热且不能真实模拟煤氧化自热过程的问题。（3）利用公斤级煤量自然发火实验台对黄陵2号煤进行了测试，得到了自然发火过程中气体和温度变化关系，结合指标气体浓度及其变化率、气体浓度比值等表征参数与煤温的对应关系，确定了煤低温氧化自然发火过程中的三个特征温度，及其量化判定依据，解决了应用指标气体量化识别煤层自燃隐蔽火源温度的问题。（4）在公斤级煤量自然发火实验测试基础上，计算得出了黄陵2号煤样的放热强度、耗氧速度和实验自然发火期等自燃特性参数，拟合出煤氧复合作用过程中自燃宏观表征参数与温度的函数关系，确定了常数项，为煤自然发火的数值模拟和发火期计算提供了关键参数。（5）通过与大型（西安科技大学XK-III）和程序升温实验台进行实验对比分析表明，公斤级煤量自然发火实验可以用于煤自然发火过程测试、煤自燃表征参数的准确测定以及煤的自燃倾向性确定，对现场自然发火预测预报及自燃危险性判定有重要意义。
[Abstract]:In recent years, the quantitative characterization of spontaneous combustion characteristics of coal and the accurate determination of the risk degree of coal spontaneous combustion are the hot and difficult points in the field of coal mine safety.
On the basis of the theoretical study of coal oxygen adsorption and spontaneous combustion characteristics, the main macroscopic characterization parameters of coal spontaneous combustion are determined, and an experimental device for spontaneous combustion of kilogram grade coal is designed, and a new method of experimental testing of spontaneous combustion of coal and natural ignition period is proposed. The experimental test analysis of No. 2 coal in Huangling has obtained the macroscopic characterization parameters of coal spontaneous combustion, determined the standard experimental conditions, and compared with the natural ignition experiment of large coal and the temperature programmed experiment, which shows that the experimental device combines the advantages of the above two kinds of experimental systems, and has the characteristics of fast speed and accurate determination of the macroscopic characterization parameters of coal spontaneous combustion. The standard of coal spontaneous combustion and experimental determination of spontaneous combustion period provides theoretical and experimental basis. The main innovative achievements are as follows:
(1) based on the pore structure of coal and the relationship between the adsorption type and heat of coal to oxygen, the effect of different types of coal on coal oxidation and self heat during the low temperature oxidation of coal is analyzed, and the coal oxidation and heat and mass transfer theory and the related mathematical model are used to determine the self heat process of coal oxidation, combining the law of coal ignition and its influencing factors. The key parameters of the numerical calculation are the oxygen consumption rate and the heat release intensity of coal, which provide theoretical support for the testing method of the characterization parameters of coal spontaneous combustion.
(2) combined with the heat release and heat dissipation characteristics of broken coal, the experimental requirements were analyzed from coal quantity, adiabatic condition, control precision and corresponding software and hardware. The experiment set up a kilogram grade coal spontaneous combustion experiment device, the heat dissipation value of the device could satisfy the heating of coal oxidation, and realized the experiment of natural oxidation temperature rising of coal 7.1kg coal. The simulation has solved the problem of large amount of coal spontaneous combustion, large amount of experimental work, small coal quantity need external heating, and can not really simulate the oxidation and self heating process of coal.
(3) to test the coal of Huangling No. 2 by a kilogram grade coal spontaneous combustion test platform, the relationship between gas and temperature changes during the spontaneous combustion process is obtained, and the corresponding relation between the parameters of the index gas concentration and its change rate, the ratio of gas concentration and the coal temperature is obtained, and the three characteristic temperatures in the process of spontaneous combustion of coal at low temperature oxidation are determined. And its quantitative determination basis solves the problem of identifying the hidden fire source temperature of coal spontaneous combustion by using indicator gas quantification.
(4) on the basis of the natural ignition test of the kilogram grade coal, the parameters of the spontaneous combustion characteristics such as the exothermic intensity, the oxygen consumption rate and the natural ignition period of the coal sample No. 2 of Huangling are calculated, and the function relation between the macroscopic characterization parameters of spontaneous combustion of coal and the temperature is fitted out, and the constant term is determined, which is the numerical simulation of the spontaneous combustion of coal. The calculation of the firing period provided the key parameters.
(5) through the comparison and analysis with the large scale (Xi'an University of Science And Technology XK-III) and the temperature programmed test bench, it is shown that the natural firing experiment of kilogram grade coal can be used to test the spontaneous combustion process of coal, the accurate measurement of coal spontaneous combustion characterization parameters and the determination of coal spontaneous combustion tendency, the prediction of spontaneous combustion of coal and the determination of the risk of spontaneous combustion. It is of great significance.

【学位授予单位】：西安科技大学
【学位级别】：博士
【学位授予年份】：2014
【分类号】：TD752.2

【参考文献】