高温矿井隔热支护结构传热诺谟图构建及调热降温作用机制研究

With the background of high-temperature need to be solved urgently in deep mining, we want to build the heat-transfer nomogram of heat-insulated supporting structure and study the mechanisms of control heat & cooling in high temperature mine, which will provide basis for simplified calculation, energy-saving benefit evaluation and application. For combination of different materials such as glass bead, ceramsite, coal ash, etc, we will optimize materials combination and mixing amount by orthogonal proportion test，then detemine suited heat-insulated support structure. The effect of complex pore structure on heat transfer coefficient of heat-insulated supporting structure will be studied on account of heat and mass transfer theory in porous media, and then we can build and verify calculation model of heat conductivity coefficient. According to the correlation of influence factors, the coordinated system of nomogram can be built.theorefore, we can draw and the heat-transfer nomogram of heat-insulated supporting structure and summarize its application method. Through building heat-transfer model of surrounding rock and supporting structure system, we will analyze the effect factors of heat-regulating circle such as temperature and thermal conductivity of surrounding rock, thickness and thermal conductivity of supporting structure, speed and temperature of airflow, etc. Based on the above research, the mechanisms of control heat & cooling will be put forward by analyzing the interaction among heat rejection of surrounding rock, heat insulation of supporting structure and energy consumption. The research results can be used in coal mine, metal mine, tunnel engineering, and other fields.

以煤炭深部开采迫切需要解决的高温热害问题为背景，研究高温矿井隔热支护结构传热诺谟图构建及调热降温作用机制，为简化隔热支护结构导热参数计算、调热降温效能评价和推广应用提供依据。针对玻化微珠、陶粒、粉煤灰等不同组合的隔热支护材料，通过正交配比试验优化材料组合和掺量，确定满足工程要求的隔热支护结构；以多孔介质传热传质理论为基础，研究复合孔隙结构对隔热支护结构传热系数的影响，构建、检验和修正导热系数计算模型。依据影响因素的相关性确定诺谟图坐标系统，绘制隔热支护结构的传热系数计算诺谟图，总结利用诺谟图计算传热系数的方法。建立围岩-隔热支护结构体系的传热模型，分析原岩温度与等效导热系数、支护结构导热系数与厚度、风流速度与温度等因素对调热圈的影响，分析调热圈岩体散热、支护结构隔热和调热降温能耗之间的相互作用，提出隔热支护结构的调热降温作用机制。研究成果可在煤炭开采、金属矿山和隧道工程等领域推广应用。

项目以煤炭深部开采面临的高温热害为工程背景，研究隔热支护结构的传热特性和调热降温作用机制，旨在完善隔热支护结构应用于降温工程的理论基础，为促进矿井热害综合防治技术的推广提供依据，为矿井高温热害综合防治技术的发展夯实基础。.基于正交试验设计了改性玻化微珠陶粒复合隔热混凝土的18组配合比，得到其导热系数在0.19W（/m·k）~0.40W/(m·k)之间，获得了抗压强度与陶粒掺量、导热系数与玻化微珠掺量、抗压强度与玻化微珠掺量之间的变化关系，基于Maxwell-Eucken model推导出适用于复合隔热混凝土的导热系数计算模型。根据试验结果分析得出添加剂掺量比重在6%~12%范围内，当掺量超过12%时隔热混凝土强度会急剧下降，最终得出当两种隔热材料的掺加比例为（1:1.7）~（1:4）时满足工程要求。基于实验结果和模型计算结果，绘制了孔隙率-导热系数-抗压强度诺谟图，从而可以根据隔热混凝土的孔隙率来对材料的导热系数和抗压强度的范围作出预判，也可以在导热和强度性能确定条件下，来对隔热材料的掺量进行一个大致预测，从而简化繁杂的导热系数计算过程，便于科研和工程技术人员应用。.通过分析隔热支护结构的传热模式，构建了围岩一支护体系传热模型的控制方程组，给出了不同情况下的定解条件，并采用异步长有限差分法进行了求解验证。相似模型试验及数值模拟结果表明，隔热材料的添加并未改变巷道围岩温度的变化趋势，总体呈现随深度增加而提高，但是温度梯度、热流密度和热流量随深度而降低，在隔热支护结构和围岩交界处温度梯度会发生突变，结合傅里叶传热理论理论得到隔热结构通过降低围岩内外界面温度差，降低了温度梯度和热流密度，从而延缓围岩向巷道传递热量，达到调热降温目的。调热圈半径随隔热层厚度减少、导热系数增加而增加，且隔热层越厚降温隔热效果越明显，当厚度为0.2m~0.3m时，隔热支护混凝土的性价比最优，随着服务年限的延长可大幅度节约降温成本。