Simulation Of Performance Of Proton Exchange Membrane Fuel Cell System

Along with the increasing seriousness of environmental pollution, the hydrogen as a clean energy has been paid much attention by all countries. As one of the hydrogen technology carriers, the proton exchange membrane fuel cell technology for its advantages such as high efficiency ,zero emissions and low noise to becomes the most extensively studied and the fastest-growing branch in the field of fuel cell. In order to provide the reference for design and optimization of proton exchange membrane fuel cell system, the operation system mathematical modeling and system simulation is very necessary.Firstly, a lumped steady-state model for PEMFC is established based on Matlab/Simulink software and the empirical equations to study the impact on the operating parameters, including the operating temperature, gas pressure and so on. On the basis of steady-state lumped parameter model, considering the effect of electric double layer capacitance affect cell response characteristics, a dynamic lumped parameter model is established. Keeping the reaction gas pressure and temperature unchanged, analyze the response characteristics of output voltage, power and efficiency when the dynamic model was simulated by step change of load current. On the basis of dynamic lumped parameter model, adding thermal management module,analyze the changes of stack temperature under different load current.Then, the dynamic lumped parameter model of humidifier, gas water separator and injector in the system are established based on Matlab/Simulink software and empirical equation. Firstly, a heat and mass transfer model of the humidifier is established, and analyze the impact of the operating parameters, including the gas temperature and cooling water temperature and the structure parameters such as inner diameter and tube length, on the humidification performance of the humidifier.Secondly, the gas water separator which is cylindrical structure use the empirical equations to establish the MM model, and analyze the impact of gas-water separator structural parameters and power of stack on the gas water separator separation efficiency. Finally, the dynamic lumped parameter model of subsonic jets which uses the convergent nozzle is established, and analyzes the impact of the nozzle diameter,the diameter of the mixing chamber on ejector performance. The PEMFC operation system is established using the stack model and accessories model, and analyze the impact on operating parameters and structural parameters on the system outputperformance. To simulate a stable electricity generation process of the fuel cell systemadding increment PID controller in the system to control the output voltage of the system, analyze the changes of the output parameters of the system with the load current step changes.In addition, in order to facilitate the adjustment of operation parameters, this article uses Matlab/GUI software package to write the human-computer interaction interface. The different operation parameters can be input directly through the interface, then call Simulink module to simulate the fuel cell performance.