OS5-01 低温型と高温型を直列配置した平板型SOFC発電のサイクル解析(OS5 水素・燃料電池)

Abstract

In this study, two-stage SOFC cycle by series connection of low- and high-temperature SOFCs (Lanthanum gallate and YSZ electrolyte, respectively) and a gas turbine has been studied. This cycle can extend the operating temperature range of SOFC and may increase a total power generation efficiency. This report has estimated system efficiency by cycle analysis of two-stage SOFC power generation with gas turbine. Fuel and air recirculation and external reforming have been adopted in this calculation. Physical properties and activation overpotential of low-temperature SOFC were based on recent published data and they are relatively superior to those of high-temperature SOFC. The analysis result shows the SOFC power generation efficiency of 50.3% and total power generation efficiency of 56.1% under a standard condition (low-temperature FC average temperature: 1023K, current density: 0.3A/cm^3, cell pressure: 1.0MPa, total fuel utilization ratio at PCs: 85%). The total power generating efficiency increases with increases of low-temperature SOFC average temperature and fuel and air utilization ratios, respectively. It also shows a positive cell pressure dependence, but peaks out around 1.0MPa.