矿井进风井巷围岩调热机理及应用基础研究

Lagging Effect of Storage Heat in Surrounding Rock of Mine Airway,So that the inlet shaft on the roadway air temperature has a “cut peak fill valley”regulation,So into the air shaft is also known as heat transfer circle.But so far,Quantitative expression of the heat transfer function of the mathematical model is still not established.The role of the heat transfer circle is beneficial should be strengthened or harmful should be suppressed is still inconclusive.Due to lack of scientific theoretical guidance,the two technical measures that improving the air flow in order to strengthen the role of the surrounding rock heat transfer and road insulation are not implemented, it is free to let the heat to exchange between the wind and the surrounding rock.It is of great theoretical significance and application value to study the mechanism of heat transfer in the surrounding rock of the tunnel.This research is based on the combination of theoretical analysis, numerical simulation, laboratory and field test,the mathematical model of the surrounding rock heat transfer in the tunnel is established under the condition of periodic variation of airflow temperature and mass transfer,the mechanism of temperature change of surrounding rock and the temporal and spatial evolution of surrounding rock temperature field are revealed,quantitative evaluation of the method and criterion of the thermal regulation of the surrounding rock of the tunnel is established.Therefore, it provides theoretical basis and technical support for scientifically guiding mine thermal disaster prevention and control work.

由于矿井进风井巷围岩蓄放热的滞后效应，使得进风井巷对巷道风流温度具有“削峰填谷”的调节作用，因此进风井巷也被称作调热圈。但是迄今为止，定量表达调热圈调热作用的数学模型仍然没有建立起来。调热圈的作用是有益的应该予以强化，还是有害的应该予以抑制，至今仍无定论。由于缺乏科学的理论指导，提高风量以强化围岩调热作用、巷道隔热保温两类技术措施都未实施，而是顺其自然、放任热量在风流和围岩之间自由交换。深入研究井巷的围岩调热机理对矿井热害防治具有重大理论指导意义和应用价值。本课题采用理论分析、数值模拟、实验室及现场测试相结合的研究方法，建立巷道风流温度周期性变化及传质条件下的井巷围岩传热数学模型，揭示围岩调热机理及围岩温度场的时空演化规律，建立定量评价井巷围岩调热作用的方法和判据。从而，为科学地指导矿井热害防治工作提供理论依据和技术支持。

矿井内风流在流向采掘工作面的过程中，总是受到其流经路线上各热源的影响，其中井巷围岩对入井风流的温度具有“削峰填谷”的调节作用，从而出现风流周期性变化。本项目首先对高温矿井各项异性围岩的导热系数进行了分析研究，研究了微裂缝导致热量传递存在各向异性对巷道围岩的温度场分布的影响，得到了进风井巷各向异性的围岩当量导热系数计算方法。其次，对周期性风流温度变化下的围岩传热传质数学模型的构建进行了研究，提出了进风井巷风温周期性变化特征规律，构建了反映井巷围岩与风流复杂热湿交换、周期性风温变化边界条件下的围岩非稳态传热传质数学模型。然后借助于数值模拟软件对井巷围岩温度场时空演化规律进行解算，对前述构建的围岩非稳态传热传质数学模型进行数值模拟解算，分析围岩温度场在不同条件影响下的变化过程，进而揭示井巷围岩温度场的时空演化规律。最后设计开发了井巷围岩相似物理模拟试验系统，验证了周期性风流温度下巷道围岩温度场数值模拟所得出的规律。结合矿井实际热物理数据，对围岩调热作用的量化进行了定量判别简化，基于井巷围岩全年吸放热的比值，提出了综合评判指标，确定了科学合理的井巷围岩调热作用定量评价方法。本项目的研究成果为高温矿井热害防治工作的科学决策和合理设计奠定了基础。