【作者】 陈清华；

【导师】 张国枢；

【作者基本信息】 安徽理工大学 ， 安全技术及工程， 2009， 博士

【摘要】 我国目前煤矿安全生产形势不容乐观,据统计有50%左右的矿井开采有自然发火危险煤层,我国国有重点煤矿的自然发火率可达0.2次/Mt以上,地方煤矿还要严重。煤自燃火源不能迅速、准确定位是造成火灾重大损失的重要原因之一。针对目前煤炭自燃火源定位技术研究中所需的松散煤体的导热系数等热物性参数不能准确测定(误差大)、松散煤体的温度场分布规律及其影响因素未进行深入研究的现状,开展了松散煤体热物性参数测试方法与测定系统、松散煤体的温度场分布规律及其影响因素的深入研究,为实现对煤炭自燃火源的准确定位奠定基础。本论文在对现有测定方法和测定装置结构进行较全面调研分析的基础上,研究并提出了同时测算松散煤体导热系数、导温系数和比热容的新方法;设计并建造了智能化的松散煤体热物性测试系统,并利用测试系统研究了导热系数等热物性随温度、含水率、空隙率等主要影响因素的变化规律;在对松散煤体温度场进行理论研究的基础上,在地面建立了大型(4×2.4×1.5m)松散煤体的试验煤堆,利用人工热源(50℃～350℃)对其不同高温热源的温度场分布规律及其影响因素进行试验研究。通过测试系统的调试和应用表明,系统实现了自动控温、自动采集数据、自动判断数据有效性、自动处理数据;在大试样量条件下,热物性参数测试结果的可重复误差小于1%;松散煤体的温度场试验模拟了自燃热源温度从50℃到350℃时不同距离、不同时间的温度场变化规律,为温度法进行火源定位技术提供依据。基于传热学理论,建立松散煤体温度场数学解析模型。据此,计算的温度场结果与试验数据基本吻合、利用煤堆试验数据对松散煤体进行热物性参数估计的结果与系统测试数据基本相符。更多还原

【Abstract】 The current situation of coal production in our country allows for no optimism, it shows according to statistics that 50% of coal mines have spontaneous combustion hazard seam, the spontaneous combustion broken ratios of key state-owned coal mine can arrive at 0.2 times per Mt, and it is worse with the local coal mines. One of the important reasons is that the source of coal spontaneous combustion can not located rapidly and accurately, which leads to a great loss.Accoding to the status that the thermophysical parameters of loose coal needed for the location of coal spontaneous combustion heat source is difficult to be measured accurately and distribution of temperature field in loose coal and its influencing factors are not yet intensively researched, the measuring method and measuring system of loose coal thermophysical parameters and distribution of temperature field in loose coal and its influencing factors are studied, which offer foundation for accurate locating of coal spontaneous combustion heat source.Based on comprehensive research and analysis of existing measuring method and measuring system, a new method of measuring thermal conductivity,thermal diffusivity and thermal capacity for loose coal is put forward, an intelligent loose coal thermophysical properties measuring system is designed and built, and then change of loose coal thermophysical parameters with temperature, water content, voidage is studied. Based on theoretical investigation of loose coal temperature field, experimental coal stockpile(4×2.4×1.5m) is built on the ground, the distribution and influencing factors of temperature field is studied by artificial heat source(50℃～350℃).The debugging and practical application of the measuring system show that the auto-controling temperature, auto-data acqusiting, auto-judging data’s validity, and auto-processing data are realized.Repeating precision of measurement results for loose coal thermophysical parameters is less than 1%. Distribution of temperature field at different distance and at different time with temperature of heat source from 50℃to 350℃is simulated, which offer foundation for the locating technology of coal spontaneous combustion heat source by the temperature method. Based on the theory of heat transfer, mathematical model of loose coal temperature field is built, through which the calculating results of temperature field are in accordance with experimental data and parameter estimating results of loose coal thermophysical are in line with measurement results.更多还原