Dynamic modeling of a hybrid system of the solid oxide fuel cell and recuperative gas turbine

Abstract

The hybrid solid oxide fuel cell (SOFC) and gas turbine (GT) system is a promising concept in the future power generation for its high-performance and low-emission. The dynamic model for the hybrid system of integrated SOFC and recuperative GT with air reheating component is presented in this work. A dynamic model was put forward based on the conservation equations of mass, energy and force through the whole plant, with specific source terms in different types of components. The SOFC was modeled on the basis of the Exponential Decay function and the Exponential Associate function, which describe the characteristics of the parameters distribution within the SOFC. A cubic curve was employed to denote the compressor pressure characteristics. In the turbine model, the relation between the work done and the inlet condition of turbine was determined according to the turbine nozzle work characteristics. The developed system model was programmed and implemented in the simulation tool Aspen Custom Modeler. The current density of SOFC was selected as disturbance variable during the dynamic simulation using the developed dynamic model. The responses of the SOFC air inlet temperature, SOFC outlet temperature, and turbine inlet temperature, the output voltage, and the gas species molar fractions at the outlet of SOFC were presented. The obtained results show that the presented dynamic model can be able to simulate the system dynamic track reasonably.