Waste heat recovery from a flame-assisted fuel cell utilizing recompression supercritical CO2 Brayton and dual-pressure organic Rankine cycles

A Flame-assisted Fuel Cell is the combination of the Solid Oxide Fuel Cell with fuel-rich combustion. In this work, two different bottoming power cycles i.e., the RSCBC and the DORC are employed to the waste heat recovery of a methane-fueled Flame-assisted Fuel Cell (FFC). Energy and exergy analyses of the FFC-RSCBC combined cycle show that this combination improves the energy and exergy efficiencies from 18.62% to 22.91% and 18.05% -22.21%, respectively. The cathode inlet air is preheated by the exhaust gases from fuellean combustion in the FFC-DORC combined cycle, which increases the efficiency. The improvements in energy and exergy efficiencies are 20.54-20.94% and 19.91-20.3% respectively. Comparison of the performance of the proposed cycles show that the FFCRSCBC generates more power compared to the FFC-DORC (_WFFC-RSCBC = 184.4 kW; _WFFC-DORC = 168.6 kW) and the exergy loss of FFC-RSCBC and FFC-DORC is 22.02 kW and 3.46 kW, respectively.(c) 2023 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.