Investigation of Condensing Ice Heat Exchangers for MTSA Technology Development
Metabolic heat regenerated Temperature Swing Adsorption (MTSA) technology is being developed for thermal and carbon dioxide (CO2) control for a Portable Life Support System (PLSS), as well as water recycling. CO2 removal and rejection is accomplished by driving a sorbent through a temperature swing starting at below freezing temperatures. The swing is completed by warming the sorbent with a separate condensing ice heat exchanger (CIHX) using metabolic heat from moist ventilation gas. The condensed humidity in the ventilation gas is recycled at the habitat. Designing a heat exchanger to efficiently transfer this energy to the sorbent bed and allow the collection of the water is a challenge since the CIHX will operate in a temperature range from 210 K to 280 K. The ventilation gas moisture will first freeze and then thaw, sometimes existing in three phases simultaneously.