Design of a solid oxide fuel cell (SOFC) combined cycle power plant

• Main Author: Ma, Wenjing
• Other Authors: Zhao Jiyun
• Format: Theses and Dissertations
• Language: English
• Published: 2015
• Subjects: DRNTU::Engineering::Electrical and electronic engineering
• Online Access: http://hdl.handle.net/10356/65129
• Institution: Nanyang Technological University

Compared with fossil fuels that emit green house gas, Fuel cell is probably the potential choice of energy in 21 st century, including solar energy, wind and nuclear energy. Among all types of fuel cells, Solid Oxide Fuel Cells attracts the most attention nowadays. The operating temperature of the solid oxide fuel cells is very high. And, this quality shows that it is possible to add extra devices to the SOFC to construct a hybrid system. When hydrogen and oxygen are fed into the fuel cell, electrochemical reactions in the fuel cell could generate power and heat. However, there is still some unreacted fuel gas at the exit of the fuel cell. Therefore, further burning the products arising from the fuel cell may increase the power generation as well as the efficiency. In this study, SOFC combined with gas turbine power system model is introduced. And a combustor model is also introduced to bum the unreacted fuel. This process can generate more heat and increase the gas temperature directly. The high temperature gas from the combustor chamber expands in the gas turbine which generates more power and increases the power efficiency, indirectly. Based on the mass and energy balance as well as thermal dynamics, a 0-D SOFC turbine model is introduced. The other two models are also the formulations of thermal dynamics and gas flow process. The Simulink model for the system is derived from the electrochemical and gas flow process. Based on the figures obtained from Simulink simulation, a series of comparisons are made to configure the influence of input variables such as current density, temperature and pressure in order to explore optimal operating conditions.