高压环境下新型四唑基固体推进剂热稳定性与燃烧机理研究

Considering the great damages to the ozonosphere, the production and use of Halon 1301 fire suppressant have been limited in fire protection engineering. To develop an environmentally-friendly Halon alternative fire-fighting technique becomes an important subject for the aircraft fire suppression technology. As a newly emerging Halon alternative candidate in aircraft dry bays and weapon bays, Solid Propellant Gas Generator (SPGG), which is firstly proposed by Next Generation Fire Suppression Technology Program, has drawn substantial attention and shown broad application prospects because of its superior ability to propel high boiling point fire extinguishing agent, to generate inert gases in fractions of a second, and easy storage prior to activation. SPGG is composed of three parts, the driving source “tetrazole-based solid propellant”, the liquid fire extinguishing agent, and the enclosed chamber with a bursting diaphragm. Once the tetrazole-based propellant ignited, large amounts of inert gases will be generated. Before reaching the pressure threshold of the bursting diaphragm, the high-pressure inert atmosphere will be maintained inside the enclosed chamber. However, under such high pressure environment, the burning rate of tetrazole-based propellant will become unstable, together with the high ejected gas temperature, which is not desirable considering the needs of fire-fighting effectiveness. This shortcoming severely limits the implement and development of SPGG fire-fighting technology..Aimed at the technical difficulty of keeping a stable and fast ejecting rate with low temperature, this program optimizes the propellant formulation through changing oxidants and negative catalysts, and studies thermal stability and combustion mechanisms for tetrazole-based solid propellant under high pressure atmosphere. This program will analyze the variation of the pyrolysis characteristic quantity and the typical combustion characteristic parameter for tetrazole-based propellant coupling the stoichiometric ratio and particle size of additional agents, reveal its mastering mechanism for propellant’s pyrolysis reaction rate and burning rate under high pressure, create the burning rate prediction model based on the analysis of characteristic quantities of pyrolysis, propose a reliable formulation optimization design method for tetrazole-based propellant, and lastly obtain a kind of ideal propellant formulation with the low outlet temperature as well as a stable and fast burning rate. .Results of this program will improve the applicability of tetrazole-based propellant in SPGG’s enclosed chamber. It will provide valuable basic theories for the formulation design of solid propellant, as well as an important data support for compression design of SPGG fire-fighting apparatus. Results of this study will eventually promoting the popularization and application of SPGG fire extinguishing technique in aircraft dry bays and weapon bays.

发展高效环保型哈龙替代技术是当前飞机灭火领域面临的重要课题，固体推进式灭火技术凭借可配合使用高沸点灭火剂、可常压贮存、响应速度快等优势，在飞机干舱、弹舱展现出良好的应用前景。在固体推进式灭火装置的高压反应腔内，作为其驱动源的四唑基推进剂存在高压下燃温高、燃速不稳定等缺点，严重制约装置灭火效果。本项目针对如何在降低推进剂燃温的前提下保证燃速快且稳定的技术难题，开展高压环境下新型四唑基推进剂热稳定性与燃烧机理研究，探究推进剂微尺度热解行为与小尺度燃烧行为的相关性，创建基于热解特征量分析的推进剂燃烧特征参数预测模型，提出可靠的配方优化设计方法，获得一种可在高压下保持低燃温、快燃速、低燃速压力指数的新型四唑基推进剂。本项目将提高四唑基推进剂在固体推进式灭火装置高压腔室内的适用性，为新型推进剂配方设计、固体推进式灭火装置耐压设计提供理论支撑，促进固体推进式哈龙替代灭火技术在飞机干舱、弹舱中的应用。

发展高效环保型哈龙替代技术是当前飞机灭火领域面临的重要课题，固体推进式灭火技术凭借可配合使用高沸点灭火剂、可常压贮存、响应速度快等优势，在飞机干舱、弹舱展现出良好的应用前景。在固体推进式灭火装置的高压反应腔内，作为其驱动源的四唑基推进剂存在高压下燃温高、燃速不稳定等缺点，严重制约装置灭火效果。如何解决推进剂在高压下燃温高与燃速不稳定的问题，已成为了推进剂领域研究的热点。为了优化四唑基固体推进剂的热解和燃烧行为，本研究将开展对新型四唑基推进剂配方设计及样品表征研究，揭示不同类型催化剂及改性方法对5-氨基四氮唑的热稳定性及热解速率控制机理，探究新型四唑基推进剂燃烧特征参数及催化燃烧作用机制，以期研制出新型的四唑基推进剂配方，实现在降低燃温的同时增强燃速稳定性，揭示SPGG高压反应腔内燃气与灭火剂微粒的相互作用机理，提高SPGG装置的防火抑爆效果。本研究可为四唑基推进剂配方的设计、优化、和应用提供可靠的理论支撑。