Numerical simulation of exchange membrane fuel cells in different operating conditions

Miniature and micro fuel cells continue to advance as promising alternatives for efficient and portable electric power. This paper presents a study of experimental modifications to the exit flow configuration of microchannels used in small proton-exchange-membrane fuel cells. New concepts for exit geometry are presented, which promote effective water removal and provide reactant back-pressure in an efficient and self-contained manner. Cell assembly is designed such that reactants must necessarily flow laterally through the gas diffusion electrodes near the exit, rather than simply pass over the free backside surfaces of these electrodes. Multiple prototypes were produced using microfabrication techniques with channel sizes of 100 and 200 microns, and performance was tested using a hydrogen-air test station with programmable electronic load. One of the new concepts in particular showed a marked improvement from 28 mW/cm2 peak power density under baseline conditions to 37 mW/cm2 for the modified design under similar operating conditions. The design offers an opportunity for higher performance in miniature fuel cells with low gas consumption and no additional cost.

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Design of a Climate Chamber to Study Transient Performance of a Proton Exchange Membrane Fuel Cell at Near Freezing Temperatures

2010 14th International Heat Transfer Conference, Volume 5 ◽

10.1115/ihtc14-23291 ◽

2010 ◽

Author(s):

Daniel Cassar ◽

Xia Wang

Keyword(s):

Fuel Cells ◽

Proton Exchange Membrane ◽

Internal Heat ◽

Proton Exchange ◽

Operating Conditions ◽

Nafion Membrane ◽

Thermoelectric Device ◽

Climate Chamber ◽

Freezing Temperatures ◽

Exchange Membrane

Freezing temperature startup of fuel cells is a serious issue for smaller applications such as auxiliary or backup power units. To accurately test and examine this problem, a laboratory climate chamber is required which can accurately represent possible environments. This research designed a climate chamber using thermoelectric (peltier) heat pumps to provide temperatures down up to −10 degrees Celsius. The internal heat absorption from air utilized forced convection while heat emitted by the thermoelectric device was removed by flowing water channels. A copper plate was used to provide separation between the heat absorbing plate and the thermoelectric heat pump. The unit showed accurate temperature control and successful operation at sub-zero temperatures. Two proton exchange membrane fuel cells with 117 Nafion membrane and 212 Nafion membrane were tested in the climate chamber under various operating conditions. The startup performance was examined under both freezing and non-freezing temperatures. Heated and humidified feed gasses were shown to greatly improve the steady state time of the 117 setup by over 30%.

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Measurements Based Analysis of the Proton Exchange Membrane Fuel Cell Operation in Transient State and Power of Own Needs

Energies ◽

10.3390/en13020498 ◽

2020 ◽

Vol 13 (2) ◽

pp. 498

Author(s):

Andrzej Wilk ◽

Daniel Węcel

Keyword(s):

Fuel Cells ◽

Fuel Cell ◽

Proton Exchange Membrane ◽

Transient State ◽

Experimental Tests ◽

Cell System ◽

Proton Exchange ◽

Operating Conditions ◽

Variable Load ◽

Exchange Membrane

Currently, fuel cells are increasingly used in industrial installations, means of transport, and household applications as a source of electricity and heat. The paper presents the results of experimental tests of a Proton Exchange Membrane Fuel Cell (PEMFC) at variable load, which characterizes the cell’s operation in real installations. A detailed analysis of the power needed for operation fuel cell auxiliary devices (own needs power) was carried out. An analysis of net and gross efficiency was carried out in various operating conditions of the device. The measurements made show changes in the performance of the fuel cell during step changing or smooth changing of an electric load. Load was carried out as a change in the current or a change in the resistance of the receiver. The analysis covered the times of reaching steady states and the efficiency of the fuel cell system taking into account auxiliary devices. In the final part of the article, an analysis was made of the influence of the fuel cell duration of use on obtained parameters. The analysis of the measurement results will allow determination of the possibility of using fuel cells in installations with a rapidly changing load profile and indicate possible solutions to improve the performance of the installation.

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Optimization of the Operating Parameters of a Proton Exchange Membrane Fuel Cell for Maximum Power Density

Journal of Fuel Cell Science and Technology ◽

10.1115/1.1867978 ◽

2005 ◽

Vol 2 (2) ◽

pp. 121-135 ◽

Cited By ~ 36

Author(s):

A. Mawardi ◽

F. Yang ◽

R. Pitchumani

Keyword(s):

Fuel Cells ◽

Fuel Cell ◽

Power Density ◽

Proton Exchange Membrane ◽

Proton Exchange ◽

Operating Conditions ◽

Optimum Operating ◽

Design Parameters ◽

Membrane Thickness ◽

Exchange Membrane

The performance of fuel cells can be significantly improved by using optimum operating conditions that maximize the power density subject to constraints. Despite its significance, relatively scant work is reported in the open literature on the model-assisted optimization of fuel cells. In this paper, a methodology for model-based optimization is presented by considering a one-dimensional nonisothermal description of a fuel cell operating on reformate feed. The numerical model is coupled with a continuous search simulated annealing optimization scheme to determine the optimum solutions for selected process constraints. Optimization results are presented over a range of fuel cell design parameters to assess the effects of membrane thickness, electrode thickness, constraint values, and CO concentration on the optimum operating conditions.

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Thermodynamic Analysis of the Performance of an Irreversible PEMFC

Defect and Diffusion Forum ◽

10.4028/www.scientific.net/ddf.388.350 ◽

2018 ◽

Vol 388 ◽

pp. 350-360 ◽

Cited By ~ 1

Author(s):

Chang Jie Li ◽

Ye Liu ◽

Zhe Shu Ma

Keyword(s):

Fuel Cells ◽

Fuel Cell ◽

Proton Exchange Membrane ◽

Pem Fuel Cells ◽

Proton Exchange ◽

Operating Conditions ◽

Operating Pressure ◽

Controllable Factors ◽

Temperature Operating ◽

Exchange Membrane

An irreversible model of proton exchange membrane fuel cells working at steady-state is established, in which the irreversibility resulting from overpotentials, internal currents and leakage currents are taken into account．In this paper, the irreversibility of fuel cell is expounded mainly from electrochemistry. The general performance characteristic curves are generated including output voltage, output power and output efficiency. In addition, the irreversibility of a class of PEMFC is studied by changing the operating conditions (controllable factors) of the fuel cell, including effect of operating temperature, operating pressure and leakage current. The results provide a theoretical basis for both the operation and optimal design of real PEM fuel cells．

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