MODELING AND CONTROL OF SOLID OXIDE FUEL CELL GAS TURBINE POWER PLANT SYSTEMS

by Hahn, Adam

There is extensive research taking place involving fuel cell gas turbine combined power plant systems. These systems use a high temperature fuel cell and a gas turbine to achieve higher overall performance and efficiency than a single mode power plant. Due to the high temperature of the exhaust gasses of the fuel cell, heat can be recuperated and used to drive a gas turbine. The turbine creates additional power and is a means of utilizing the exhaust energy of the fuel cell. Despite the research being done on integrating these systems, little work has been done to characterize the dynamics of the integrated systems. Due to the high response of the fuel cell and the relatively sluggish response of the turbine, control of the system needs to be understood. This thesis develops dynamic models of the individual components that comprise a fuel cell gas turbine hybrid system (axial flow compressor, combustor, turbine, fuel cell, and heat exchanger). These models are incorporated to produce a complete dynamic hybrid model. The models are analyzed with respect to dynamics and basic control techniques are used to control various parameters. It is shown that the system can be controlled using hydrogen input flow rate control for the fuel cell and controlled turbine inlet temperature for the gas turbine.