A singularly perturbed model is proposed for a system comprised of a PEM Fuel Cell(PEM-FC) with Natural Gas Hydrogen Reformer (NG-HR). This eighteenth order system is decomposedinto slow and fast lower order subsystems using singular perturbation techniques that provides tools forseparation and order reduction. Then, three different types of controllers, namely an optimal full-order,a near-opti...

Passenger vehicles fueled by hydrocarbons or alcohols and powered by proton exchange membrane (PEM) fuel cells address world air quality and fuel supply concerns while avoiding hydrogen infrastructure and on-board storage problems. Reduction of the carbon monoxide concentration in the on-board fuel processor’s hydrogen-rich gas by the preferential oxidizer (PrOx) under dynamic conditions is cru...

Among a number of alternative energy sources, hydrogen is treated as one of the most promising candidates, due to the reason that it can be applied to a fuel cell as an input to provide electricity through an electrochemical reaction. On top of that, high conversion efficiency up to 40 to 60% is seen in a fuel cell. The first application of a Proton Exchange Membrane (PEM) fuel cell was as an a...

The water management is a critical problem to overcome in the PEM fuel cell technology. Models play an important role in fuel cell development since they enable the understanding of the influence of different parameters on the cell performance allowing a systematic simulation, design and optimization of fuel cells systems. In this work, a model previously developed and validated, is used to pre...

in order to present a new and high performance structure of pem fuel cell and study the influence of the flow direction and distribution on the rate of reactants diffusion, three novel models of vertical reactant flow injection into the anode and cathode reaction area field have been introduced. they consist of one inlet and two inlets and also a continuous channel. the governing equations on t...

a three dimensional, compressible, steady, one phase flow of reactant-product mixture in the air side electrode of proton exchange membrane fuel cell (pemfc) is numerically studied in this paper. the mixture is composed of three species: oxygen, nitrogen and water vapor. the performance of the cell is enhanced by partial blockage of the flow field channels. various types of these blocks also ca...

An effort is underway to develop a prototype Proton Exchange Membrane (PEM) Fuel Cell breadboard system for fuhlre space applications. This prototype will be used to develop a comprehensive des ign basis for a space-rated PEM fuel cell powerplant. The prototype system includes reactant pressure regulators, ejector-based reactant pumps, a 4-kW fuel cell stack and cooling system, and a passive, m...

In this research the simulation of an air independent Proton Exchange Membrane Fuel Cell (PEMFC) propulsion system was taken into consideration. The system consists of several parts including PEM fuel cell stack, metal hydride and liquid oxygen (LOX) tanks, and also pre-heaters of oxygen and hydrogen gases along with other heat exchangers, to ensure proper operation of system. The heat recovery...

The design of electrodes for polymer electrolyte membrane fuel cells (PEMFC) is a delicate balancing of transport media. Conductance of gas, electrons, and protons must be optimized to provide efficient transport to and from the electrochemical reactions. This is accomplished through careful consideration of the volume of conducting media required by each phase and the distribution of the respe...

The dynamic response of the stirred tank reactor (STR) polymer electrolyte membrane (PEM) fuel cell has been explored over the temperature range of 35–105 ◦C. When the fuel cell was operated in the autohumidification mode the fuel cell current “ignited’’ when the membrane water content was greater than a critical level of ∼1.6 H2O/SO3, and it extinguished when the initial membrane water content...