In this paper, the platelet heat exchanger in the thermal propulsion system of micro satellite with liquefied gas as propellant was designed, the complete gasification and stabilization scheme of propellant was proposed. The unsteady conjugate heat transfer (CHT) characteristics between the heat exchanger and gaseous propellant were analyzed, and the cumulative data of error estimation in the numerical simulation process was provided to ensure the credibility of the results. The CHT computational fluid dynamics (CFD) simulation of the platelet 3D model under steady-state conditions was carried out to find the empirical correlation between the average Nusselt number and the average Reynolds number. A simplified unsteady 1D model of heat exchanger was established by using the loose coupling method based on quasi steady flow field. The results show that the platelet structure could heat the working medium to more than 2379 K with the heat transfer efficiency of 86%, the outlet temperature and heat transfer efficiency of the heat exchanger were maintained at 1871K and 69% in steady state when the mass flow rate was 1.14e-6 kg/s. The 1D model could accurately reflect the real heat transfer situation to a certain extent, the simulation error was less than 8.5% compared with the 3D model, and the calculation time was greatly shortened, making the adjustment of heat transfer strategy more convenient. Intermittent heat transfer method could keep the outlet gas temperature, thrust and specific impulse of the thruster at a high level to improve the performance of the system. Taking the nanosatellite with a total mass of 7.55 kg and a propellant mass of 0.25 kg as an example, when the duration of valve open time was 1.5s, the velocity increment of the satellite reached 72.21 m/s with the specific impulse of over 2400 m/s, which was twice than that of nanosatellites without heat exchange structure.

本文设计了以液化气为推进剂的微型卫星热推进系统中的片状换热器，提出了推进剂的完整气化稳定方案。分析了换热器与气体推进剂之间的非定常共轭传热（CHT）特性，并提供了数值模拟过程中误差估计的累积数据，以保证结果的可信度。对稳态条件下的血小板 3D 模型进行 CHT 计算流体动力学 (CFD) 模拟，以找到平均努塞尔数和平均雷诺数之间的经验相关性。采用基于准稳态流场的松耦合方法建立了换热器的简化非稳态一维模型。结果表明，片状结构可以将工质加热到2379 K以上，传热效率为86%，当质量稳定时，换热器出口温度和传热效率分别保持在1871K和69%。流速为 1.14e-6 kg/s。一维模型能够在一定程度上准确反映真实的传热情况，与3D模型相比，仿真误差小于8.5%，计算时间大大缩短，使传热策略的调整更加方便。间歇传热方式可以使推进器的出口气体温度、推力和比冲保持在较高水平，从而提高系统的性能。以总质量为 7.55 kg、推进剂质量为 0.25 kg 的纳米卫星为例，