| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 1278169 | International Journal of Hydrogen Energy | 2013 | 12 Pages |
A pressurized solid oxide fuel cell–gas turbine hybrid system (SOFC–GT system) has been received much attention for a distributed power generation due to its high efficiency. When considering an energy management of the system, it is found that a heat input is highly required to preheat air before being fed to the SOFC stack. The recirculation of a high-temperature cathode exhaust gas is probably an interesting option to reduce the requirement of an external heat for the SOFC–GT system. This study aims to analyze the pressurized SOFC–GT hybrid system fed by ethanol with the recycle of a cathode exhaust gas via a simulation study. Effect of important operating parameters on the electrical efficiency and heat management of the system is investigated. The results indicate that an increase in the operating pressure dramatically improves the system electrical efficiency. The suitable pressure is in a range of 4–6 bar, achieving the highest system electrical efficiency and the lowest recuperation energy from the waste heat of the GT exhaust gas. In addition, it is found that the waste heat obtained from the GT is higher than the heat required for the system, leading to a possibility of the SOFC–GT system to be operated at a self-sustainable condition. Under a high pressure operation, the SOFC–GT system requires a high recirculation of the cathode exhaust gas to maintain the system without supplying the external heat; however, the increased recirculation ratio of the cathode exhaust gas reduces the system electrical efficiency.
► A pressurized SOFC–GT hybrid system run on ethanol is studied. ► Effect of pressure and cathode gas recirculation on SOFC system performance is analyzed. ► An increase in the operating pressure improves the system electrical efficiency. ► The cathode gas recirculation can reduce the external heat input but degrades the system efficiency. ► The SOFC–GT system with cathode gas recycle can be operated at a self-sustainable condition.
