长征五号运载火箭助推动力系统

Booster Stage Propulsion System for Launch Vehicle Long March 5

关键词:  运载火箭  液氧煤油发动机  助推器  技术特征  推重比

Key words:  Launch vehicle  Liquid oxygen kerosene engine  Booster  Technical characteristics  Thrust-to-weight ratio

摘要:

长征五号是我国新一代大型运载火箭（代号CZ-5），芯级捆绑四个助推器，每个助推器配置两台并联的液氧煤油高压补燃发动机。本文对国内外运载火箭的故障模式进行分析，结合CZ-5火箭首飞实际情况，提出了助推动力系统风险规避应采取的措施。针对CZ-5火箭助推级和芯一级发动机起动点火的特点，分析了CZ-5火箭首次发射中的异型发动机点火匹配特性。简述了YF-100系列液氧煤油发动机的研制历程、技术特征和热环境适应性，重点分析了发动机在可重复使用和大范围推力调节方面的潜力。对比了国内外液氧煤油补燃循环发动机的推重比性能，分析了不同发动机推重比对火箭运载能力的影响，总结了提高发动机性能的措施（如采用泵后摆技术、选用高强度轻质化材料等）。提出了新一代液氧煤油发动机必须在满足高可靠性的前提下，追求高性能、高推重比、降低成本和增强适应性的后续改进方向。

Abstract:

Long March 5 is China’s new generation of large-scale launch vehicle （code-named CZ-5）. The core stage is bundled with four boosters， and each booster uses a dual-unit parallel liquid oxygen kerosene high-pressure staged combustion engine. Considering the real situation of the first launch of the Long March 5， this paper analyzes the failure modes of launch vehicles at home and abroad， and puts forward the measures that should be taken to avoid the risk of the booster system. Combined with the starting characteristics of booster stage and the first-stage engines， the ignition matching characteristics of the different engines in the first launch of the Long March 5 are discussed. The development history， technical characteristics， and adaptability of thermal environment for YF-100 series liquid oxygen kerosene engine are briefly described， and the engine’s potential of reusability and wide-range thrust adjustment is analyzed with emphasis. The thrust-to-weight ratio of liquid oxygen kerosene staged engines is compared， the impact of engines with different thrust-to-weight ratios on the carrying capacity of rocket is studied， and the methods to improve engine’s performance are summarized （such as using pump back swing technology， high-strength and light-weight Materials， etc.）. It is pointed out that the new generation of liquid oxygen kerosene engine must pursue high performance， high thrust-to-weight ratio， lower cost and enhance adaptability under the premise of high reliability.