Long Endurance Underwater Power System
Abstract
As part of DARPA's 'Artificial Gill' program, Aquanautics is developing an underwater power source that uses an ambient pressure solid polymer electrolyte (SPE) hydrogen/oxygen fuel cell with an artificial gill that extracts dissolved oxygen from seawater and an Alwatt aluminum corrosion cell that generates the hydrogen. The innovation in this concept is a direct carrier feed fuel cell (CFFC) process which allows the fuel cell to operate at ambient pressure without a costly deep water pressure vessel. Activities during this quarter include: 1) Direct feed of oxygen carrier into fuel cell. New batches of electrodes have been ordered. These are with a different ion-exchange membrane called Nafion (manufactured by Dupont) as against Raipore (mfd. by RAI Research) . There was some concern that hydrogen at high pressures would leak out through the membrane which led us to calculate the hydrogen leakage; it appears that at 6000 m, the loss will be around 20%. 2) Gill. Eight rectangular membrane cartridges were ordered. The factors varied were type of membrane (solid vs. microporous) and fiber to fiber distance. Theoretical study for sizing of the gill and pumping power required was carried out. 3) Integration of the gill and fuel cell was carried out where oxygen extracted from synthetic ocean water was used in the fuel cell. There was no unforeseen problem. 4) Hydrogen generation. An Alwatt battery was obtained and tested. Testing indicated that the Alwatt battery will produce the expected power and hydrogen for the CFFC process. (EDC)
Document Details
- Document Type
- Technical Report
- Publication Date
- Aug 04, 1989
- Accession Number
- ADA211386