气溶胶灭火剂抑制空运锂电池热失控机理及适航性研究

For airborne halon fire extinguishing system can't effectively extinguish lithium-ion batteries fire front hot problem, Based on heat and mass transfer laws, establishing describe gas-solid two-phase heat flow field environment aerosol fire extinguishing agent particle dynamics mathematical model, based on the monte carlo algorithm of molecular dynamics of aerosol fire extinguishing agent and flame lithium-ion batteries and lithium batteries to fire suppression on probability estimation, the distribution of particles in establishing certain cast fire extinguishing aerosol fire extinguishing agent under the condition of flow and function and the numerical simulation model is established and numerical simulation; Based on aircraft cargo/ULD prototype size set up small and medium scale aerosol fire extinguishing agent movement characteristics and fire extinguishing experiment platform, is put forward under the thermal environment, aerosol fire extinguishing agent laser particle concentration measurement experiment and test, and carry out different types of lithium battery thermal runaway and class A fire extinguishing experiment, solid aerosol fire extinguishing agent volume concentration and protection of its cargo bay quantitative relationship of the space, determine the different scales of aircraft cargo/ULD total flooding fire optimal selection method. The research not only support to cargo halon extinguishing instead and airworthiness provide theory and technical, but also for lithium batteries by air safety management to provide technical guidance.

针对机载哈龙灭火系统不能有效扑灭锂电池火灾前沿热点问题，以两相传热传质规律为基础，建立描述气-固两相热流场环境下气溶胶灭火剂微粒动力学的数理模型，基于分子动力学的蒙特卡罗算法对气溶胶灭火剂与锂电池火焰及对锂电池深位火抑制的微粒分布进行概率估算，综上建立一定灭火条件下气溶胶灭火剂施放、运动及与火焰作用的数值模拟模型并进行数值模拟；依据飞机货舱/ULD原型尺寸建立中小尺度气溶胶灭火剂运动特性及灭火实验平台，提出热环境下气溶胶灭火剂微粒浓度激光测量实验方法并进行测试，开展不同类型锂电池热失控和A类固体火灭火实验，得出气溶胶灭火剂容积浓度与飞机货舱保护空间的定量关系，确定不同尺度的飞机货舱/ULD全淹没灭火优化选择方法。该研究可为飞机货舱哈龙灭火替代及适航验证提供理论和实验技术支持，对锂电池空运安全管理提供技术指导。

通过自主设计并搭建的三个不同尺度的锂电池燃爆实验平台，结合数值模拟和理论分析：发现锂电池热失控过程存在“两节点（初爆-燃爆）三阶段（稳定-临界-失控）”特征，基于此特征选择了能有效抑制锂电池热失控的最佳细水雾灭火剂；采用蒙特卡罗方法对细水雾微粒运动轨迹进行概率估算，确定热泳力和重力平衡粒径；建立细水雾抑制锂电池热失控双区域降温模型及区域热平衡方程，对细水雾灭火潜能进行预测；构建锂电池热失控多米诺效应模型，修正锂电池热释放速率曲线；定量分析锂电池热失控释放气体特性，提出空运锂电池热失控气体探测方案；利用不同尺度实验平台开展锂电池灭火剂的最低性能实验，对比不同空运条件下不同工作条件和容量的细水雾灭火效率，得到细水雾抑制空运锂电池火灾的容量、面积等定量关系，确定细水雾抑制锂电池热失控的适航性标准。通过管网计算单一喷头下细水雾系统的保护面积，并以常见AKE型飞机货舱ULD为例，将气体探测与细水雾系统集成并实现联动。该研究不仅丰富了锂电池热失控机理和细水雾灭火领域理论体系，同时也为空运锂电池安全提供了一种实际可操作的工程设计方案。