Thermodynamic investigation of the efficiency of ammonia-powered marine solid oxide fuel cells with gas turbine

Abstract

Improvement of marine power plants includes increasing their efficiency and drastically reducing emissions of pollutants, which involves transitioning to carbon-free fuels. This article discusses the evolution of a marine power system designed for decarbonization, utilizing ammonia and comprising solid oxide fuel cells with a gas turbine. To enhance efficiency, the system incorporates a steam supply into the fuel burning device of a gas turbine. By adding superheated steam, the system's performance improves significantly. Thermodynamic calculations identified optimal parameters for the gas turbine, which enhances efficiency by utilizing off-gases from the fuel cells. Key parameters include compressor and exhauster pressure ratios, which can be used to increase the specific power. A combined energy system with an overexpansion turbine achieves a total efficiency of 60.62 % at a fuel cell temperature of 1190 K during operation, with the SOFC efficiency being 43.76 %. These findings highlight potential improvements for marine power systems using ammonia and provide insights into the energy conversion processes within such hybrid systems.

Keywords

• Hybrid power system
• ammonia
• Solid oxide fuel cell
• Optimization
• Gas turbine