电控固体推进剂热分解和燃烧性能研究

Study on Thermal Decomposition and Combustion Performanceof Electrically Controlled Solid Propellant

关键词:  电控固体推进剂  同步热分析仪  热分解  燃烧波  火焰结构

Key words:  Electrically controlled solid propellant (ECSP)  Thermogravimetric-differential scanning calorimetry (TG-DSC)  Thermal decomposition  Combustion wave  Flame structure

摘要:

针对能实现多次启动和推力可控的固体火箭发动机需求，研究了成型过程快、钝感、电控性能好和贮存稳定的离子盐电控固体推进剂(ECSP)热分解和燃烧性能。采用同步热分析仪(TG-DSC)、钨铼微热电偶、单幅照相技术和扫描电镜-能谱仪，研究了ECSP的热分解特性、燃烧波温度分布、熄火表面形貌以及元素分布。结果表明:ECSP的热分解过程中依次发生PVA分解反应、PVA分解产物与LiClO4强烈相互作用，其中小组分添加剂加快了PVA分解；其燃烧区域分为预热区、凝相反应区、气相反应区；电点火到稳态燃烧过程为:通入电流加热推进剂，ECSP开始点火，释放出大量的热和可燃性气体，产生初步火焰；热解产生的气相产物在气相区域进一步燃烧，同时大量熔岩状明亮颗粒在热分解气流作用下从燃面逸出，在气相区域燃烧并发出明亮的光。本文提出了ECSP的燃烧过程，为该类推进剂燃烧物理模型奠定基础。

Abstract:

In order to meet the technical requirements of solid rocket motor for controllable thrust and multiple starts and stops， ionic salt electrically controlled solid propellant (ECSP)， which was easy preparation， insensitive， electrically controlled and stable storage， was investigated on thermal decomposition and combustion performance including the flame structure， combustion wave temperature distribution， quenched surface and element distribution. Such performances are investigated by thermogravimetric analysis(TG) and differential scanning calorimetry(DSC)， W-Re micro-thermocouple， flame photo technique， and sanning electron microscopy(SEM)-energy spectrometer. Results show that thermal decomposition process of ECSP includes that PVA firstly decomposed， then those decomposition products of PVA interact with LiClO4. In addition， other additives accelerate decomposition of PVA. The combustion wave is divided into three zones including preheating zone， solid-phase reaction zone， and gas-phase reaction zone. Moreover， the process of the ECSP from ignition applied by current to stable combustion is described. ECSP is preheated by applied electrical power， then ignited， and releasing a large number of heat and gases， finally generating primary flame. Those gases production further combust in gas-phase reaction zone. Meanwhile， a large number of lava-like bright particles are ejected from the burning surface with gas production， and burn in the gas phase. The combustion process of ECSP propellant is suggested， which builds the foundations for combustion physical model of those propellants.