Thermal Model of a Zero Boil Off System for the Nuclear Thermal Propulsion System

Plachta, David ; Wang, Xiao-Yen ; Hartwig, Jason

关键词: COOLERS;    CRYOGENIC COOLING;    EVAPORATION;    FLUID FLOW;    HEAT TRANSFER;    MASS FLOW RATE;    MICROGRAVITY;    NUCLEAR PROPULSION;    PROPELLANTS;    THERMAL INSULATION;    TUBE HEAT EXCHANGERS;    WALLS;    WORKING FLUIDS;    BOILING;   

RP-ID  :  GRC-E-DAA-TN62843

美国|英语

来源: NASA Technical Reports Server

【 摘 要 】

NASA is currently developing an updated concept for a nuclear thermal propulsion (NTP) system. To enable this concept, efficient thermal insulation and cryocooler heat exchanger systems are required to eliminate boil-off of propellant. This paper presents the results of a thermal model used to assess the feasibility of using active cooling with a tube-on-tank heat exchanger configuration for the inline tank of the NTP system. Results show that: cryocooler working fluid temperature and mass flow rate can be adjusted to achieve zero boil off (ZBO) with broad area cooling, over-sizing the cryocooler lift directly translates into a reduction in tank pressure, and broad area cooling may still maintain ZBO despite the reduced heat transfer between tank wall and propellant that is expected in reduced gravity.