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Investigating Liquid CO2 as a Coolant for a MTSA Heat Exchanger DesignMetabolic heat regenerated Temperature Swing Adsorption (MTSA) technology is being developed for thermal and carbon dioxide (CO 2) control for a future Portable Life Support System (PLSS), as well as water recycling. CO 2 removal and rejection is accomplished by driving a sorbent through a temperature swing of approximately 210 K to 280 K . The sorbent is cooled to these sub-freezing temperatures by a Sublimating Heat Exchanger (SHX) with liquid coolant expanded to sublimation temperatures. Water is the baseline coolant available on the moon, and if used, provides a competitive solution to the current baseline PLSS schematic. Liquid CO2 (LCO2) is another non-cryogenic coolant readily available from Martian resources which can be produced and stored using relatively low power and minimal infrastructure. LCO 2 expands from high pressure liquid (~5800 kPa) to Mars ambient (0.8 kPa) to produce a gas / solid mixture at temperatures as low as 156 K. Analysis and experimental work are presented to investigate factors that drive the design of a heat exchanger to effectively use this sink. Emphasis is given to enabling efficient use of the CO 2 cooling potential and mitigation of heat exchanger clogging due to solid formation. Minimizing mass and size as well as coolant delivery are also considered. The analysis and experimental work is specifically performed in an MTSA-like application to enable higher fidelity modeling for future optimization of a SHX design. In doing so, the work also demonstrates principles and concepts so that the design can be further optimized later in integrated applications (including Lunar application where water might be a choice of coolant).
Document ID
Document Type
Paul, Heather L. (NASA Johnson Space Center Houston, TX, United States)
Padilla, Sebastian (Paragon Space Development Corp. Tucson, AZ, United States)
Powers, Aaron (Paragon Space Development Corp. Tucson, AZ, United States)
Iacomini, Christie (Paragon Space Development Corp. Tucson, AZ, United States)
Date Acquired
August 24, 2013
Publication Date
January 1, 2009
Subject Category
Fluid Mechanics and Thermodynamics
Report/Patent Number
Meeting Information
40th International Conference on Environmental Systems(Barcelona)
Funding Number(s)
WBS: WBS 903184.
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