Conceptual Design and Performance Analysis of SOFC/Micro Gas Turbine Hybrid Distributed Energy System

A numerical model has been developed for the performance analysis of solid oxide fuel cell (SOFC)/micro gas turbine (MGT) hybrid systems with prereforming of natural gas, in which a quasi two-dimensional model has been built up to simulate the cell electrochemical reaction, heat and mass transfer within tubular SOFC. The developed model can be used not only to predict the overall performance of the SOFC/MGT hybrid system but also to reveal the nonuniform temperature distribution within SOFC unit. The effects of turbine inlet temperature (TIT) and pressure ratio (PR) on the performance of the hybrid system have been investigated. The results show that selecting smaller TIT or PR value will lead to relative higher system efficiency and lower CO₂ emission ratio; however, this will raise the risk to destroy SOFC beyond the limitation temperature of electrolyte.