SOEC水蒸気電解システムのサイクル計算とエクセルギー解析

抄録

Solid Oxide Electrolysis Cells (SOECs) can be used for hydrogen generator systems. In this study, two types of SOECs which have different operating temperatures, 850°C and 650°C, were treated. For 850°C-type cell, measurements of current density-voltage characteristic and current efficiency were carried out and the data of 650°C-type cell were obtained from the previous report. For 850°C-type cell, the voltage at 0.4 A/cm² was 1.20V and the current efficiency was approximately 100%. With the experimental values, cycle calculations for SOEC system models with production capacity of 300Nm³/h were carried out. At a rated operating point of 0.4A/cm², the exergy efficiencies depending on each source of supplied energy were discussed. When all energy was supplied by electricity, the exergy efficiencies were 80.2% for 850°C-type system and 80.5% for 650°C-type one. When heat of 110°C was supplied, efficiencies were 89.2% for 850°C-type system and 90.5% for 650°C-type one. When heats of 110°C and 850°C or 650°C were supplied, they were 91.4% for both systems. The efficiencies were also discussed at various electric supply loads. At the load area< 950kW, 650°C-type system had higher efficiency than that of 850°C-type one. On the other hand, at the load area> 950kW, the efficiency of 850°C system was higher.