矿井避难硐室围岩蓄冷-相变蓄热耦合降温系统特性研究

The mine refuge chamber should be cooled in order to reach the standard of temperature in 96 hours without any outside support. At present, phase-change cooling is the best way to control the temperature of coal mine refuge chamber, while the conventional measures of refrigeration cooling can not meet the thermal environment requirements of mine refuge chamber. In this work, the basic research of phase-change cooling in mine refuge chamber will be studied by using the comprehensive method of theoretical analysis, numerical calculation and experimental research. The main work is divided into the following parts: 1) three-dimensional numerical simulation and experimental validation of the unsteady heat transfer process in 96 hours; 2) the main influencing factors of the thermal environment refuge chamber will be analyzed, the impacts especially the initial temperature and the heat transfer of the wall rock on the thermal environment; 3) the heat storage characteristic of phase change unit filled with heterogeneous materials in the complex boundary, especially the phase-change device which including expanded graphite composite phase change material / metal mesh; 4) the numerical calculation and experimental research of the three-dimensional unsteady heat transfer under the wall rock-human body-phase-change device-indoor air environment coupling, and the optimization of phase-change cooling device. The research result will solve the cooling technical problems of the mine refuge chamber, and provide theory and technology for maintenance-free, low-cost, non-hazardous cooling in mine refuge chamber.

在无任何外界支持的情况下，矿井避难硐室应满足96小时额定防护时间内温度不高于35℃的强制要求。常规的制冷降温措施均存在一定的局限性，不能满足煤矿井下紧急避险系统建设的要求，相变降温是目前最具潜力的技术措施。避难硐室相变降温目前处于工程尝试阶段，尚缺系统的理论研究。课题拟采用理论分析、数值计算与实验研究相结合的方法，进行矿井避难硐室相变降温的基础研究。具体包括：避难硐室高温环境形成过程的三维非稳态传热数值模拟与实验验证；围岩的间歇蓄冷机理及其对避难硐室热环境的影响；复杂边界下内部非均质复合材料相变单元的传热特性分析，并在此基础上研究相变装置的蓄热特性；避难硐室围岩-人体-相变装置-室内空气的三维非稳态传热数值模拟与实验研究；相变降温装置与蓄冷围岩的优化配置。研究成果可为解决矿井避难硐室降温技术难题，实现易维护、低成本、无危害的有效降温提供理论基础和技术支撑。

矿井避难硐室是保障矿工生命安全的重要设施，面对矿难发生后的恶劣外部环境以及断电状况，传统降温方法都不适用。本课题针对避难硐室温度保障问题，结合热能存储技术，提出了一种适用于矿井避难硐室的围岩蓄冷-相变蓄热耦合降温方法，解决了避难硐室的温度控制难题。课题在阐明围岩换热机理的基础上，研究了耦合降温系统围岩连续蓄冷及间歇蓄冷特性，并针对不同时期工程要求，提出了快速、节能、方便的分段组合式间歇蓄冷模式。设计了适用于矿井避难硐室的相变降温装置，建立了地下封闭空间包含围岩-热源-相变装置-空气在内的非稳态传热数值计算方法，其中相变座椅还涉及复合边界条件下装置内部材料的相变、导热及自然对流。基于该数值计算方法，揭示了围岩蓄冷-相变蓄热耦合降温系统传热及控温规律，并对耦合降温系统进行了优化，提出了降温系统的优化运行策略。本课题提出的矿井避难硐室围岩蓄冷-相变蓄热耦合降温方法无需电力支持，系统安全可靠，结构简单，满足了本质安全条件下无源环境中避难硐室内降温要求，这对于缓解矿工的紧张情绪，增加矿工的被救几率具有重要作用，为井下矿工生命安全保障提供了重要的技术支撑。研究成果对于其它封闭地下空间热湿环境控制也有重要的指导意义。