民用飞机货舱细水雾灭火关键技术与实验验证

This proposal focuses on science and engineering problems for development of the next-generation fire suppression technology used in aircraft cargo compartment. This proposal will utilize various modeling and experimental methods, such as small scale fire suppression tests under low and change pressure environments, full-scale experiments, and modeling and simulations. Firstly, we will develop a next-generation low weight and high efficient water mist device, which can be integrated with other sub-systems in the aircraft. The water-mist device is based on two-fluid mechanism using water and nitrogen mixing. The important characteristics on two phase flow, atomization, shockwave and acoustics, will be investigated and important control parameters will be determined. Secondly, we will develop a water-mist system and study the fire suppression efficiency under low or change pressure. At the end, we will test the developed fire suppression system under the monitoring environment. We have built a test lab in the Kangding Airport with 4290m height. The test lab is capable of mimic flight environment from taking off to landing of the aircraft. We can therefore test the system in the near-real environment, which no place in the world can do such experiments. The proposal will study the interaction between shockwave and water-nitrogen two-phase system and determine the mechanism of water-mist production. We will further study the water-mist distribution in cargo environment and fire suppression mechanism under low and change pressure conditions.We will be able to make contributions on resolving the key scientific issues on developing the prototype of fire suppression system with proprietary intellectual property rights.

本项目关注新一代民机货舱灭火系统的关键科学技术问题，采用小尺度、全尺寸实验和数值模拟等研究方法，首先研发轻型高效且匹配机载系统的新一代细水雾产生装置，解决水-氮气两相混合、激波谐振雾化等关键科学问题，获取相关作用原理及关键控制参数；其次，研发机载细水雾灭火抑火系统，基于雾场绕流及时空特性，确定不同布局、不同压力/温度变化下系统动态响应与优化策略；最后，基于康定机场（4290米）可模拟飞机起降环境的全尺寸增减压标准货舱实验平台，研究细水雾在接近真实飞控环境下的灭火机理，并揭示飞机近场过程中的复燃机理，获得性能优越可靠的原型系统。研究将揭示气液两相流与激波谐振的相互影响及成雾机理，低压及变压下水-氮气混合细水雾的灭火抑火机理和空间扩散规律。成果为研发中国自主知识产权的机载货舱细水雾灭火系统技术原型提供理论技术支持，提升我国大飞机国产化水平，并将为国际哈龙替代研究做出中国的贡献。

本项目跟踪国际大型民机防火系统哈龙替代技术发展趋势，结合新一代机载灭火系统环保、轻量、低气压等工程技术应用环境，积极面向国家大飞机战略必需的新一代机载抑灭火技术需求，深入开展了低驱动压力双流体细水雾应用于飞行中民机货舱抑灭火的基础科学问题与关键技术研究。. 针对飞机货舱低气压/变气压环境，研究了庚烷、航煤、标准纸箱、锂电池、航空织物、航空电缆等典型可燃物的火焰高度、温度、烟气浓度等火行为特征，揭示了低气压下池火燃料蒸发区特殊行为规律，发展了低气压/变气压受限火行为燃烧模型，发现了低气压下毒害CO和CO2生成速率高于常气压的现象；针对机载灭火系统轻量化关键需求，提出了基于超音速原理的细水雾雾化方法，开发了新型低压双流体细水雾产生装置，可形成雾滴粒径可调的实验环境，研制了国内首套飞机货舱智能联控细水雾抑灭火技术原型实验系统；针对飞行中货舱抑灭火特殊需求，研究了常气压/低气压下细水雾粒径分布、雾滴速度、雾滴碰撞以及蒸发等雾场特征，发现了低气压下细水雾的雾滴粒径小于常压且两极分化、雾场分布不均匀等现象，发现了雾滴碰撞特性与无量纲韦伯数和奥内佐格数的关系，实现了基于连续温度函数的液滴碰撞三维数值模拟，揭示了固体表面温度对液滴反弹/黏附两种响应方式的影响机理，发展了低气压下细水雾雾场生产演化机理；依据国际散装货物、集装箱货物、液体表面和气溶胶等火型标准，开展了低气压及变气压下小尺寸、全尺寸飞机货舱抑灭火实验，揭示了低气压下细水雾抑灭典型固体/液体火灾机理。. 项目研究揭示了在低气压/变气压下，机舱火行为、细水雾的生成发展机理，以及细水雾吸热冷却、降烟抑尘、热辐射抑制等抑灭火机理，研究成果得到波音等国际研究机构认可，细水雾雾化技术缩短了我国在机载细水雾抑灭火技术研发领域与西方民航先进国家的差距。