Fuel Cells And Micro-gas Turbine Combined Cycle System Performance Analysis

In order to solve the energy crisis and environmental pollutions, People pay more and more attention to find a better way to use the energy with a high efficiency and low pollution. Distributed electrical power generations have been developed quickly in recent years to rationally use the energy and protect the environment. The cogeneration of hybrid cycles based on high temperature solid oxide fuel cells (SOFC) and micro-gas turbines (MGT) was developed at the end of the last century, which is a very promising distributed electrical power generation with high energy efficiency and very low environmental impact. The hybrid cycles based on MGT and SOFC have higher efficiency than SOFC cycles. As a result, hybrid cycles seem to be one of the best choices for the distributed power generations.This thesis addresses the simulation and analysis on the performance of he hybrid system based on the fuel cells and the micro-gas turbine.The first section presents the basic structure and working principle, the advantages, and the development and applications of the fuel cells. The different types and materials of the solid oxide fuel cells (SOFC) have been discussed along with the review on the modeling development of the fuel cells. A model for the tubular solid oxide fuel cell is proposed based on the mass balance, the energy balance, and the electrochemistry reaction principle. The design and part-load performances of SOFCs are discussed with consideration of the influence of the current density, the cell operating temperature, and the air utilization factor, etc.The second section discusses the basic knowledge and characteristic, the development and application of the micro-gas turbines. A model for recuperated micro-gas turbine is discussed according to the characteristic of the compressor and the turbine based on some assumptions. The model of the micro-gas turbine used in the thesis has the features of low-pressure ratio and high rotation speed. The rating and partial-load performances are discussed in detail.The third section combines the two systems discussed above into one...