Experimental Results of Integrated Refrigeration and Storage System Testing

Abstract

Launch operations engineers at the Kennedy Space Center have identified an Integrated Refrigeration and Storage system as a promising technology to reduce launch costs and enable advanced cryogenic operations. This system uses a closed cycle Brayton refrigerator to remove energy from the stored cryogenic propellant. This allows for control of the temperature and pressure of the fluid, and enables advanced operations such as zero boil off storage and zero loss transfer. If required, this also can serve as a propellant densification system or liquefier. However, the behavior of the fluid in this type of system is different than typical cryogenic storage systems, and there will be a learning curve associated with its use. A 400 liter research cryostat has been designed, fabricated and delivered to KSC to test the thermofluid behavior of liquid oxygen as energy is removed from the cryogen by a simulated DC cycle cryocooler. Results of the initial testing phase focusing on heat exchanger characterization and zero loss storage operations using liquid oxygen are presented in this paper. Future plans for testing of oxygen densification tests and oxygen liquefaction tests will also be discussed.

Mathematical model and experimental results for cryogenic densification and sub-cooling using a submerged cooling source

“…Also, this paper predicts the rate of propellant densification using a cooling source within the liquid propellant and compares the prediction to experimental results. This work is similar to the Integrated Refrigeration and Storage method proposed by Notardonato [7] [8].…”

Strategies To Improve the Performance of Hydrogen Storage Systems by Liquefaction Methods: A Comprehensive Review

“…H 2 is the main refrigerant in most of the traditional H 2 liquefaction processes. Its application includes drawbacks such as the inability to decrease the temperature below the H 2 boiling point, the high SEC of compressors, and high penetration in equipment structure due to low molecular mass and low system efficiency. , Helium refrigerant and Ne gas were proposed to solve the problems caused by H 2 ; the larger molecular mass of helium significantly reduces the power consumption, and its penetration decreases due to the larger molecules of helium. , Figure depicts the various temperature ranges of low-boiling fluids used as refrigerants for H 2 liquefaction. H 2 and helium refrigerants are the most suitable options for H 2 liquefaction.…”

Final test results for the ground operations demonstration unit for liquid hydrogen

“…If the refrigerator capacity exceeds the heat leak, the liquid can be conditioned or densified, or gaseous hydrogen can be introduced to be liquefied. Small scale demonstrations of the IRAS technology were successfully completed with liquid hydrogen in 2005 [1] at the Florida Solar Energy Center and later with liquid oxygen at the Kennedy Space Center in 2009 [2]. The GODU LH 2 project had three primary demonstration objectives for using IRAS on a relevant scale: (1) zero-loss storage and transfer of LH 2 , (2) densification of LH 2 , and (3) liquefaction of gaseous hydrogen (GH 2 ).…”