Paper presented at the 5th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, South Africa, 1-4 July, 2007.
Solid oxide fuel cells (SOFC) are considered extremely suitable for electrical power plant application. The SOFC performance is calculated using numerical models which are built in Aspen customer modeler for the internally reformed (IR) SOFCs. These models are integrated in Aspen PlusTM . In our present study, a combined cycle consisting of two-staged high-temperature SOFC (HT-SOFC) and low-temperature SOFC (LT-SOFC) was investigated. In the combined cycle the anode flow of the HT-SOFC and LT-SOFC is in parallel connected while the cathode flow is serially connected. The combined cycle and single-staged cycle with SOFC are simulated in order to evaluate and compare their performances. The simulations show that the net efficiency of two-staged combined cycle and single-staged SOFC cycle are 62% and 52% respectively under standard operation conditions. In other words, the cycle with two-staged SOFCs gives better net efficiency than the cycle with single-staged SOFC.