Presentation
Proof of Concept Design and Analysis of heat Reutilization of a Solid Oxide Electrolyzer Cell for Oxygen Supply on Mars
2018 Thermal Fluids Analysis Workshop
(2018)
Abstract
Samuel Ogletree, Shan Mohammed, and M. A. Rafe Biswas, University of Texas at Tyler As NASA seeks to lay the groundwork required for human exploration of Mars, new and innovative life support systems need to be developed. A major component of these life support systems is the reliable supply of oxygen to revitalize cabin air. Current methods of oxygen supply rely purely on resources stored from launch. While these methods work for near-Earth orbit, planned missions that extend beyond this region require large resource storage and bloated launch costs. A technology that shows promise in addressing these concerns is a Solid Oxide Electrolyzer Cell (SOEC) system involving carbon dioxide electrolysis. This technology is unique in its ability to utilize resources produced and gathered from the Martian surface and atmosphere (consists of 96% carbon dioxide) during a manned mission. However, in its current form, the system is unable to meet power consumption requirements due to the heating elements necessary to meet the high operating temperature of 800°C. To consider the Mars environment, we developed a proof of concept design of a thermal reutilization device to analyze and test on Earth. To determine the feasibility of this design, we tested in a NASA affiliated experimental facility to mimic the system operation using air as the testing gas. A customized shell and tube heat exchanger (HX) was designed and analyzed to reutilize the hot exhaust air from the system to preheat the inlet air. The HX consists of a carbon steel shell with six rectangular passes. Four carbon steel tubes make a single pass through each shell pass creating a pure counter-flow orientation. To reduce heat loss to the environment during testing, the HX was covered with two inches of ceramic fiber insulation. Air flow was controlled through a single fan at the shell inlet. For testing, air at 25°C was introduced to the shell structure at a flow rate of 20 SLPM while the tube structure was provided with 520°C air at the same flow rate. The resulting shell outlet temperature of the HX was 207.3°C giving a shell side ΔT of 182.3°C. The tube outlet temperature was 89.4°C giving a tube side ΔT of 429.6°C. The HX had a calculated effectiveness of 0.102 and reduced the required heating element power by 75 W (36.6% reduction). As a first iteration proof of concept, the HX design showed promise in addressing the SOEC system’s concerns
Disciplines
Publication Date
Fall August, 2018
Citation Information
M. A. Rafe Biswas. "Proof of Concept Design and Analysis of heat Reutilization of a Solid Oxide Electrolyzer Cell for Oxygen Supply on Mars" 2018 Thermal Fluids Analysis Workshop (2018) Available at: http://works.bepress.com/mohammad-biswas/25/