The Simulation Of The Novel Hybrid System Of Solid Oxide Fuel Cell And Gas Turbine

Solid oxide fuel cell (SOFC) is a power conversion device that directly converts thechemical energy into electrical energy. It has high efficiency, cleanness, environmental-friendly and many other advantages. With high operating temperature, SOFC can be in-tegrated with gas turbine (GT) to effectively utilize the high quality waste heat producedby fuel cell, which could further raise the system electrical efficiency. Therefore, SOFC andSOFC-GT hybrid system have a promising future in application. Currently, they are researchhot spots in many countries. In this dissertation, the following works have been conductedfor SOFC and SOFC-GT hybrid system.Firstly, with comprehensive analysis of the physical phenomenon in the interior of theSOFC, such as flow, heat transfer, mass transfer and electrochemistry, the SOFC is dividedinto four layers in geometry, that is, anode, cathode, PEN plate and interconnector. Then theconservative equations are established and discretized at each layer. At last, the simulationmodel is developed on the platform of EASY5. With comparative studies of the perfor-mances of the counter-flow and cross-flow SOFC, the results reveal that both the averagetemperature and the efficiency of the counter-flow type are higher than that of the cross-flowtype.Secondly, the model libraries for the SOFC-GT hybrid system are developed on theEASY5 simulation platform. The libraries consist of one-dimensional SOFC model, heatexchanger model, heat exchanger reformer model, combustor model, mixer model, splittermodel, blower model, volume model, compressor model, turbine model, shaft model, etc.Finally, a SOFC-GT hybrid system is designed for small and medium distributed powergeneration system. The design is characterized by that the anode recirculation and cathoderecirculation, instead of the traditionally used heat exchanger, are used to preheat of the fuelstream and air stream, which can save room and cut cost. Based on the established modellibraries, the simulation model of the hybrid system is implemented on the EASY5 platform. 52% at 50% case. In addition, the preliminary control strategy is introduced for this hybridsystem. After relevant analysis, it can be seen from the results that the control strategy couldimprove the system performance. The model validation is proved.The work in the dissertation provides important references for the design and operationof the SOFC and SOFC-GT hybrid system, and lays a solid foundation for further optimiza-tion analysis and experimental study.