Effect of Operating Parameters on Performance and Safety Evaluation of a Biogas-fueled SOFC/GT Hybrid System

In this work, a detailed model of solid oxide fuel cell (SOFC)/micro gas turbine (GT) hybrid system with a recirculation process is established on MATLAB/Simulink platform. A typical farm biogas is chosen as fuel for the hybrid system, and the coupling effects of recirculation ratio, steam/carbon (S/C) ratio and fuel/air ratio on the operating performances and safety characteristics of the hybrid system and components (such as fuel cell, reformer and gas turbine) are carefully studied. Among the calculated results, the recirculation ratio of 0.4, the S/C ratio of 2.5 and the fuel/air ratio of 0.13 are selected as appropriate parameters for operation, in this case the total output work of hybrid system is 177 kW, and electrical efficiency could reach 59.4%. Results show that under properly selected operation parameters, the biogas-fueled hybrid system has good performance characteristics with both high efficiency and enough safety range. (C) 2019 The Authors. Published by Elsevier Ltd.