Abstract
The isobaric subcooling cryogenic propellants are of higher density, lower vapor pressure and higher sensible cooling capacity over their saturated state, which could bring beneficial impacts on the vehicle weight, engine performance and storage time. Among several subcooling methods, pumping decompression method and heat exchange method are emphatically compared, and three system schemes including subcooling before, during and after loading are illustrated and analyzed. For the target of rapidly obtaining subcooled LO2 below 70 K, the simultaneous subcooling scheme with an atmospheric and a subatmospheric LN2 bath heat exchangers is rec-ommended, where the water-ring vacuum pump is adopted to realize the depressurization. A semi-industry scale experiment facility was designed and built up. Results show that, with conditions of LO2 flow rate ranged from 0.2 L/s to 2.7 L/s, the temperature of LO2 at the outlet of the secondary heat exchanger was always below 70 K, successfully verifying the feasibility and effectiveness of this subcooling system. The minimum subcooling temperature of LO2 was about 66.6 K at around 2.2 L/s (the rated flow rate was designed as 2.0 L/s), indicating the reasonability of the system design. The present study can provide reference for the future applications of the subcooling cryogenic propellants.
NSTL
Elsevier