Dynamic Thermal Model and Temperature Control of Proton Exchange Membrane Fuel Cell Stack

A dynamic thermal transfer model of a proton exchange membrane fuel cell (PEMFC) stack is developed based on energy conservation in order to reach better temperature control of PEMFC stack. Considering its uncertain parameters and disturbance, we propose a robust adaptive controller based on backstepping algorithm of Lyaponov function. Numerical simulations indicate the validity of the proposed controller.

Study and performance test of 10 kW molten carbonate fuel cell power generation system

The use of high-temperature fuel cells as a power technology can improve the efficiency of electricity generation and achieve near-zero emissions of carbon dioxide.This work explores the performance of a 10 kW high-temperature molten carbonate fuel cell.The key materials of a single cell were characterized and analyzed using X-ray diffraction and scanning electron microscopy.The results show that the pore size of the key electrode material is 6.5 lm and the matrix material is a-LiAlO_(2).Experimentally,the open circuit voltage of the single cell was found to be 1.23 V.The current density was greater than 100 mA/cm^(2)at an operating voltage of 0.7 V.The 10 kW fuel cell stack comprised 80 single fuel cells with a total area of 2000 cm^(2)and achieved an open circuit voltage of greater than 85 V.The fuel cell stack power and current density could reach 11.7 kW and 104.5 mA/cm2 at an operating voltage of 56 V.The influence and long-term stable operation of the stack were also analyzed and discussed.The successful operation of a 10 kW high-temperature fuel cell promotes the large-scale use of fuel cells and provides a research basis for future investigations of fuel cell capacity enhancement and distributed generation in China.

Influence of PTFE on Electrode Structure for Performance of PEMFC and 10-Cells Stack

Water plays a critical role on the performance, stability and lifetime of proton exchange membrane fuel cells（PEMFCs）. The addition of poly tetrafluoroethylene（PTFE） to the gas diffusion layer, especially, the cathode side, would optimize the transportation of water, electron and gas and thus improve the performance of the fuel cell. But until now, the studies about directly applying the PTFE to the catalyst layer are rarely reported. In this paper, the membrane electrode is fabricated by using directly coating catalyst to the membrane method（CCM） and applying PTFE directly to the cathode electrode catalyst layer. The performance of the single cell is determined by polarization curves and durability tests. Electrochemical impedance spectroscopy（EIS） and scanning electron microscopy（SEM） techniques are used to characterize the electrochemical properties of PEMFC. Also the performance of a 10-cells stack is detected. Combining the performance and the physical-chemistry characterization of PEMFC shows that addition of appropriate content of PTFE to the electrode enhances the performance of the fuel cell, which may be due to the improved water management. Addition of appropriate content of PTFE enhances the interaction between the membrane and the catalyst layer, and bigger pores and highly textured structure form in the MEA, which favors the oxygen mass transfer and protons transfer in the fuel cell. While superfluous addition of PTFE covers the surface of catalysts and hindered the contact of catalyst with Nation, which leads to the reduction of electrochemical active area and the decay of the fuel cell performance. The proposed research would optimize the water management of the fuel cell and thus improve the performance of the fuel cell.

Micro PEM Fuel Cells and Stacks

1 Results The effects of different operating parameters on micro proton exchange membrane (PEM) fuel cell performance were experimentally studied for three different flow field configurations (interdigitated,mesh,and serpentine).Experiments with different cell operating temperatures and different backpressures on the H2 flow channels,as well as various combinations of these parameters,have been conducted for three different flow geometries.The micro PEM fuel cells were designed and fabricated in-house t...

A new artificial bee swarm algorithm for optimization of proton exchange membrane fuel cell model parameters

An appropriate mathematical model can help researchers to simulate,evaluate,and control a proton exchange membrane fuel cell (PEMFC) stack system.Because a PEMFC is a nonlinear and strongly coupled system,many assumptions and approximations are considered during modeling.Therefore,some differences are found between model results and the real performance of PEMFCs.To increase the precision of the models so that they can describe better the actual performance,opti-mization of PEMFC model parameters is essential.In this paper,an artificial bee swarm optimization algorithm,called ABSO,is proposed for optimizing the parameters of a steady-state PEMFC stack model suitable for electrical engineering applications.For studying the usefulness of the proposed algorithm,ABSO-based results are compared with the results from a genetic algo-rithm (GA) and particle swarm optimization (PSO).The results show that the ABSO algorithm outperforms the other algorithms.

Nonlinear modeling based on RBF neural networks identification and adaptive fuzzy control of DMFC stack

The temperature models of anode and cathode of direct methanol fuel cell （DMFC） stack were established by using radial basis function （RBF） neural networks identification technique to deal with the modeling and control problem of DMFC stack. An adaptive fuzzy neural networks temperature controller was designed based on the identification models established, and parameters of the controller were regulated by novel back propagation （BP） algorithm. Simulation results show that the RBF neural networks identification modeling method is correct, effective and the models established have good accuracy. Moreover, performance of the adaptive fuzzy neural networks temperature controller designed is superior.