THERMODYNAMIC ANALYSIS OF A SOLID-OXIDE FUEL CELL GAS TURBINE (SOFC-GT) HYBRID SYSTEM FOR MARINE APPLICATIONS

The maritime industry serves a pivotal role in global trade and transportation, yet its contribution to environmental pollution, notably emissions, poses a critical concern. Addressing and mitigating the carbon footprint of this industry has become imperative amidst the challenges posed by climate change. This study presents a thermodynamic analysis focused on a Solid Oxide Fuel Cell-Gas Turbine (SOFC-GT) hybrid system designed for marine applications. The integration of Solid Oxide Fuel Cells (SOFCs) with gas turbines holds significant promise for augmenting the efficiency and sustainability of marine propulsion systems. A steady-state thermodynamic model for the SOFC-GT was developed using ASPEN PLUS software, integrating built-in modules and functions along with a Fortran code specifically designed for SOFC electrochemistry. To ascertain the model's accuracy, validation was performed against NASA’s SOFC model, established using the Numerical Propulsion System Simulator (NPSS), and publicly accessible data from a Westinghouse 120kW tubular SOFC. Both datasets exhibited a matching within a 1% error margin, validating the reliability of our model. Having established confidence in the model's accuracy, this study investigates the intricate interactions between the SOFC and gas turbine components within the hybrid system. The incorporation of the gas turbine for heat recovery in the hybrid system utilizing the Westinghouse tubular SOFC showcased a notable increase in thermal efficiency, elevating it from 50% to 62%. The proposed hybrid system is compared to an existing marine gas turbine and has demonstrated improved thermal efficiency and reduced fuel consumption but fell short in terms of energy density.