Proton Exchange Membrane Fuel Cell System Characteristics Simulation Study

With the ever-increasing energy crisis and serious environmental pollutions around the world, it is one of the strategic issues for the people to explore new technologies to use the energy with efficiency and low pollutions. As a new electrochemical energy-conversion technology, Proton exchange membrane fuel cell (PEMFC) has many advantages, such as high efficiency, no or low pollution, simple and safe in construction, noise free and quick startup even at low operating temperatures. As a result, PEMFC is considered as one of the most promising energy-conversion technologies of efficiency and clean for the 21^th century. Extensive and systematic mathematical modeling and simulation are needed to provide fundamentals and reliable data for the effective design, optimization and controlling strategy for single fuel cell, stacks, and entire fuel cell systems. Therefore, the modeling and simulation study of PEMFC is one of the most important research issues in the field of PEMFC.The characteristics and classifications of the fuel cells are briefly summarized in the first chapter. A brief overview is conducted on the operating principle of PEMFC, function and characteristics of each important element. The state-of-the-art is presented of the mathematical modeling and simulation research of PEMFC conducted both in China and abroad.A lumped steady-state model for PEMFC is presented using the semi-empirical equations in terms of the system engineering. Effects of the operating parameters, such as the working temperature, gas pressures on the fuel cell system are studied in detail. A system-level dynamic model of PEMFC is further developed, which incorporates the effects of charge double-layer capacitance, transient mass and heat transfer processes in the anode and cathode channels, and transient heat transfer process in the fuel cell body. The transient response characteritics are analyzed on the cell voltage, power, cathode and anode channel temperatures and pressures, and temperature of the cell under the sudden change conditions in the fuel cell loads. The proposed models are implemented in SIMULINK software package in MATLAB to simulate the dynamic characteristics of PEMFC. Good matchs are achieved between the simulation results and the experimental data reported in the open literature. The developed simulation methods will be useful for the analysis, optimal design, and real-time control study of PEMFC systems.At last, a computer software is developed for simulating the characteristic parameters of proton exchange membrane fuel cells based on the MATLAB and Visual Basic software packages. The simulating results show that the developed software can be a practical simulating tool for investigating the PEMFC characteristics with friendly user-interface and low cost.