Research On Thermal Control Scheme Of Liquid Hydrogen On-orbit Storage

At present,the mission of space exploration has been widely valued by countries all over the world.As China's space technology continues to develop and progress,and space missions continue to increase,more and more spacecraft are continuously being sent into space.As the technical requirements of space missions become higher and higher,the operations that need to be performed in space become more complex.Liquid hydrogen fuel has become the preferred propellant for deep space exploration because of its high efficiency and pollution-free performance.However,compared with traditional propellants,the extremely low boiling point of liquid hydrogen makes it more difficult to storage and apply in complex space thermal environment.In order to carry out manned aerial missions such as Mars exploration and lunar exploration,cryogenic propellants such as liquid hydrogen on-orbit storage technology is a key technology that must be mastered.In this paper,the heat transfer process of spacecraft in space thermal environment is studied theoretically,and the thermal protection mechanism of sun shield,multi-layer insulation structure and vapor-cooled shield in space environment is obtained.The heat transfer model of the sun shield composed of multi-layer insulation materials is analyzed,and the thermal protection performance and influencing factors of the sun shield are simulated and analyzed.The thermal protection schemes of the planar sun shield and the conical sun shield are established,and the liquid hydrogen storage foundation scheme on orbit is put forward through the simulation results of the two schemes.Finally,combined with the planar sun shield model,the conical sun shield model and the liquid hydrogen on-orbit storage foundation model proposed before,a dual sun shield liquid hydrogen on-orbit zero evaporation storage thermal protection scheme is proposed.The simulation results show that the liquid hydrogen tank can reach the low temperature region near 18 K,and the propellant loss caused by the liquid hydrogen evaporation can be effectively prevented.At the same time,aiming at some special space missions which have definite restrictions on the total weight of spacecraft thermal protection measures,the thermal protection scheme of double shield is improved in quality,and the thermal protection scheme of liquid hydrogen storage with low weight dual shield on orbit by zero evaporation is put forward.