镁基水反应金属燃料的热分解性能

Thermal decomposition characteristics of magnesium-based hydroreactive metal fuel

关键词:  水冲压发动机+  金属燃料  热分解  活化能  反应速率

Key words:  Water ramjet+  Metal fuel  Thermal decomposition  Activation energy  Reaction rate

摘要:

采用热重-差热分析联用(TG-DTA)、差示扫描量热(DSC)、加压热重(PTG)等热分析方法,研究了镁基水反应金属燃料热分解反应的基本特性及其变化规律。研究发现,燃料热分解过程中先后发生AP分解反应、HTPB分解反应,氩气中不发生Mg的氧化反应;添加催化剂、减小AP粒度、增大氧化剂与粘合剂比例、增大细Mg粉含量等,可以降低燃料中AP的分解温度T,减小表观活化能Ea,增大反应速率常数k;减小AP粒度、增大氧化剂与粘合剂比例可以降低燃料中HTPB的分解温度,减小表观活化能Ea,增大反应速率常数k;随着压强增大,AP与HTPB分解失重速率增大、AP失重百分数增大、燃料热分解凝聚相产物质量百分数减少,压强对AP分解影响较大,对HTPB分解影响较小。

Abstract:

The thermal decomposition characteristics of the magnesium-based hydroreactive metal fuel were investigated by means of various thermal analysis methods, such as TG-DTA, DSC and PTG. The results showed that the thermal decomposition of AP and HTPB in the fuel occurs sequentially as temperature increases, and there is no oxidation of Mg in Ar atmosphere. Adding catalyst, decreasing particle sizes of AP, increasing the ratio of oxidant to binder or decreasing the average particle sizes of Mg could decrease the decomposition temperature T and activation energy Ea and increase decomposition rate constant k of AP. Decreasing particle sizes of AP or increasing the ratio of oxidant to binder could decrease the decomposition T, Ea and increase decomposition k of HTPB. With pressure increasing, both the mass loss rate of AP and HTPB and mass loss of AP increase while the weight of condensed products decrease. The decomposition of AP was influenced more greatly than decomposition of HTPB by pressure.