Dynamic characteristics and fast load following of 5-kW class tubular solid oxide fuel cell/micro-gas turbine hybrid systems

Combining solid oxide fuel cell and gas turbine (SOFC/GT) system is a promising concept for future clean and efficient power generation. An SOFC/GT system exploits the complementary features of the two power plants, where the GT recuperates the energy in the SOFC exhaust stream and thereby boosts the overall system efficiency. Through model-based transient analysis, however, it is shown that the intricate coupling dynamics make the transient load following very challenging. The purpose of this study is to examine the load-following capability of 5-kW class SOFC/micro-GT hybrid systems in two different configurations: single-shaft and dual-shaft GT designs. An optimal load-following operation scheme, aimed at achieving a proper trade-off between high steady-state efficiency and fast transient response is developed through model-based dynamic analysis and optimization. Simulation results are reported to illustrate the effectiveness of the proposed optimal scheme. Copyright (c) 2013 John Wiley & Sons, Ltd.