氢氧末级长时间滑行贮箱压力控制及关键技术分析

为通过弹道优化设计提升火箭发射圆轨道卫星的运载能力，同时提高火箭对不同发射任务的适应性，需要火箭末级具备长时间在轨滑行能力。对氢氧末级火箭而言，延长在轨滑行时间需要解决的一个重要问题是液氢贮箱压力、推进剂温度的预示和控制。结合微重力下贮箱内低温推进剂力热耦合运动特征，给出了低温火箭在轨滑行过程中贮箱压力控制的设计流程和计算方法，并通过计算分析获得了整个滑行阶段液氢蒸发量、补压气瓶需求量等关键设计参数，为工程研制提供参考。

Pressure Control and Key Technology of Hydrogen/Oxygen Upper Stage with Long-Duration Coasting Flight

In order to improve the launch capability of the rocket to launch circular orbit satellites through trajectory optimization design, and improve the adaptability of the rocket to different launch tasks, the upper stage rocket needs to have the ability of a long-duration coasting in orbit. For hydrogen/oxygen upper stage rocket, an important issue that needs to be addressed to extend the coasting time is the prediction and control of hydrogen tank pressure and propellant temperature. In consideration of the characteristic of the force-thermal coupling movement in cryogenic propellant tank under microgravity, the design flow and calculation method of tank pressure control during coasting flight are given. Then, key design parameters such as evaporation of liquid hydrogen and demand of pressurization bottles in the whole coasting phase are obtained, which can provide reference for engineering development.