System Analysis of Planar Solid Oxide Fuel Cell Combined with Gas Turbine

Abstract

The planar solid oxide fuel cell (SOFC) with the Y2O3 stabilized ZrO2 electrolyte is expected to be a candidate for the distributed power sources in the next generation due to its high efficiency of power generation. In this study, we have analyzed the system performance of the SOFC and gas turbine combined cycle of about 500 kW output, using a two-dimensional simulation program for planar SOFC with the internal reforming. The effects of cell temperature, SOFC pressure, recirculation ratios of fuel and air, utilization ratios of fuel and air, and average current density at SOFC on the system efficiency were analyzed under typical operating condition taking account of realistic efficiencies and heat losses. The addition of Cheng cycle to the SOFC and gas turbine combined cycle improves the system efficiency by 1—3%. The 500 kW class SOFC, gas turbine and Cheng combined cycle gives the high efficiency of 61.2% (HHV) under the typical condition when the SOFC pressure is set to about 2.0 MPa.