深井开采原岩内部及其与风流的固-液-气三相耦合传热换湿热害形成机理研究

Because of the high temperature of original rock temperature, the long ventilation line and the sufficient heat and moisture transfer, heat harm is serious in deep mining. Based on percolation mechanics, fluid mechanics and heat and mass transfer theory, this project studies heat conduction between wall surface of deep entry and deep original rock, solid-fluid coupled heat transfer between water seepage flow of the wall rock pore, unstable and convective heat and moisture transfer of gas-liquid-solid three-phase coupled between the wet wall surface of well lane and air flow, the theory of heat and moisture transfer between the water at the roadway and air flow and formation mechanism of high temperature and high humidity, the main influencing factors in the process of convective heat and moisture transfer of gas-liquid-solid three-phase coupled: lithology, original rock porosity, primary temperature difference of original rock temperature and the wall surface, water pressure difference, primary temperature difference of the wall surface and air flow, the influence law of unstable heat and moisture transfer by humidity difference and wind speed, establishs the unified mathematical model for heat and mass transfer process between original rock, water and air flow in mine, uses the established model of coupling between air flow, temperature and humidity field in mine excavation space for numerical simulation of distribution of air temperature and humidity field; proposes active temperature control technology for changing heat and moisture transfer, calculates heat and moisture load of mine passive attemperation. The research results have important theoretical significance and practical value of cooling and dehumidifying in deep of high temperature and high humidity mine, air conditioning, health protection of coal miners, guarantee safety production.

深井开采原岩温度高，通风路线长，换热换湿充分，矿井热害严重。本项目以渗流力学、流体力学、传热传质学等理论为基础，研究深井巷道壁面与原岩深部热传导、围岩孔隙中的水渗流与围岩之间的固-液耦合传热、井巷潮湿壁面与风流之间的固-液-气耦合的不稳定对流换热换湿、巷道水与风流的换热换湿原理及高温高湿热害形成机理，研究固-液-气耦合的不稳定对流换热、换湿的主要影响因素：岩性、原岩孔隙率、原岩与井巷壁面的初始温差、水压差、井巷壁面与风流的初始温差、湿差和风速对不稳定换热、换湿的影响规律，建立矿井原岩-水-风流间传热传质过程的统一数学模型；运用所建立的矿井采掘空间风流场、温度场、湿度场耦合的模型，进行风流温度、湿度场分布的数值模拟；提出改变热湿交换的主动控温技术，计算矿井被动调温的热、湿负荷。本项目的研究对深部高温、高湿矿井降温、减湿、空调、保障矿工健康、保证安全生产具有重要的理论意义和使用价值。

项目针对深井开采原岩温度高，通风路线长，换热换湿充分，矿井热害严重的问题，通过对人体热舒适度、事故率、劳动效率等研究，提出了我国矿山热害标准的修改建议，将原来的高温标准由26℃提高到28℃；实验研究了煤岩体导热系数变化规律：温度升高，煤、岩的导热系数和热扩散系数降低，比热容增大，含水量增加煤岩的热扩散系数、比热容和导热系数均增大，密度增大煤岩的导热系数增大，灰分增加煤的导热系数、热扩散系数都增大，挥发分含量增大煤的导热系数和热扩散系数都减小；研究了巷道围岩与风流的传热传质耦合机理，得出了干燥表面巷道围岩温度场和围岩与风流不稳定换热系数的解析表达式；推导了柱坐标系下湿润巷道的径向围岩导热控制方程；建立了矿井煤岩体内部热湿传导、井巷壁面与风流的不稳定热湿交换的统一数学模型；研究主动隔热支护降温技术，得出隔热层导热系数是影响隔热效果的决定因素，风流温度降低值与隔热层的导热系数和通风时间呈负指数关系，与隔热层厚度呈正幂指数关系；研究矿井采掘空间热环境的数值模拟及矿井空调的热湿负荷计算及风流温、湿度场分布的数值模拟；提出了利用液态二氧化碳进行矿井降温的新方法，并研制了技术装备，进行了实验和工业试验。.通过该项目研究提出了矿井热害经济、环保型治理的理念，研究成果对高温矿井热害治理技术的研究具有重要的科学意义和前瞻性的指导意义，对经济、节约、环保型治理热害具有重要的实际意义。