A closed-cycle hydrogen combustion system with Stirling engine for AUV propulsion

A closed-cycle hydrogen combustion system equipped with Stirling engine is developed for the propulsion of large Autonomous Underwater Vehicles (AUVs). Complete hydrogen reaction in the combustion chamber of engine is assured by excessive oxygen. The flame temperature of hydrogen is controlled by dilution gas and water vapor. Combustion product, i.e., water vapor condenses to water liquid, and drains out from the closed-cycle. Simplifications of controller are pursued to increase operational reliability. A demonstration system is manufactured and tested. The test results have justified the adequacy of design concepts. The system is expected to be a promising energy supplier in terms of reliability and cost effectiveness.