scholarly journals Development of an Oxygen Pressure Estimator Using the Immersion and Invariance Method for a Particular PEMFC System

Processes ◽  
2020 ◽  
Vol 8 (9) ◽  
pp. 1095
Author(s):  
Ángel Hernández-Gómez ◽  
Victor Ramirez ◽  
Belem Saldivar

The fault detection method has been used usually to give a diagnosis of the performance and efficiency in the proton exchange membrane fuel cell (PEMFC) systems. To be able to use this method a lot of sensors are implemented in the PEMFC to measure different parameters like pressure, temperature, voltage, and electrical current. However, despite the high reliability of the sensors, they can fail or give erroneous measurements. To address this problem, an efficient solution to replace the sensors must be found. For this reason, in this work, the immersion and invariance method is proposed to develop an oxygen pressure estimator based on the voltage, electrical current density, and temperature measurements. The estimator stability region is calculated by applying Lyapunov’s Theorem and constraints to achieve stability are established for the oxygen pressure, electrical current density, and temperature. Under these estimator requirements, oxygen pressure measurements of high reliability are obtained to fault diagnosis without the need to use an oxygen sensor.


2005 ◽  
Vol 86 (23) ◽  
pp. 234101 ◽  
Author(s):  
Roberto S. Aga ◽  
Xiang Wang ◽  
Jonathan Dizon ◽  
Jesse Noffsinger ◽  
Judy Z. Wu


Author(s):  
Utku Gulan ◽  
Hasmet Turkoglu ◽  
Irfan Ar

In this study, the fluid flow and cell performance in cathode side of a proton exchange membrane (PEM) fuel cell were numerically analyzed. The problem domain consists of cathode gas channel, cathode gas diffusion layer, and cathode catalyst layer. The equations governing the motion of air, concentration of oxygen, and electrochemical reactions were numerically solved. A computer program was developed based on control volume method and SIMPLE algorithm. The mathematical model and program developed were tested by comparing the results of numerical simulations with the results from literature. Simulations were performed for different values of inlet Reynolds number and inlet oxygen mole fraction at different operation temperatures. Using the results of these simulations, the effects of these parameters on the flow, oxygen concentration distribution, current density and power density were analyzed. The simulations showed that the oxygen concentration in the catalyst layer increases with increasing Reynolds number and hence the current density and power density of the PEM fuel cell also increases. Analysis of the data obtained from simulations also shows that current density and power density of the PEM fuel cell increases with increasing operation temperature. It is also observed that increasing the inlet oxygen mole fraction increases the current density and power density.



1991 ◽  
Vol 136 (2-3) ◽  
pp. 217-233 ◽  
Author(s):  
Dimitris A. Retalis


1999 ◽  
Author(s):  
C. Y. Wang ◽  
Z. H. Wang ◽  
Y. Pan

Abstract Proton exchange membrane (PEM) fuel cells have emerged, in the last decade, as a viable technology for power generation and energy conversion. Fuel cell (FC) engines for vehicular applications possess many attributes such as high fuel efficiency, low emission, quiet and low temperature operation, and modularity. An important phenomenon limiting fuel cell performance is the two-phase flow and transport of fuel and oxidant from flow channels to reaction sites. In this paper a mathematical model is presented to study the two-phase flow dynamics, multi-component transport and electrochemical kinetics in the air cathode, the most important component of the hydrogen PEM fuel cell. A major feature of the present model is that it unifies single- and two-phase analyses for low and high current densities, respectively, and it is capable of predicting the threshold current density corresponding to the onset of liquid water formation in the air cathode. A numerical study based on the finite volume method is then undertaken to calculate the detailed distributions of local current density, oxygen concentration, water vapor concentration and liquid water saturation as well as their effects on the cell polarization curve. The simulated polarization curve and predicted threshold current density corresponding to the onset of liquid water formation for a single-channel, 5cm2 fuel cell compare favorably with experimental results. Quantitative comparisons with experiments presently being conducted at our laboratory will be reported in a forthcoming paper.



2019 ◽  
Vol 969 ◽  
pp. 461-465
Author(s):  
Matha Prasad Adari ◽  
P. Lavanya ◽  
P. Hara Gopal ◽  
T.Praveen Sagar ◽  
S. Pavani

Proton exchange membrane fuel cell (PEMFC) system is an advanced power system for the future that is sustainable, clean and environmental friendly. The flow channels present in bipolar plates of a PEMFC are responsible for the effective distribution of the reactant gases. Uneven distribution of the reactants can cause variations in current density, temperature, and water content over the area of a PEMFC, thus reducing the performance of PEMFC. By using Serpentine flow field channel, the performance is increased. Two types of serpentine flow field channels are implemented such as curved serpentine flow field channel and normal serpentine flow field channels. The result shows that curved serpentine flow field channel gives better current density and power density, thus increasing the performance of PEMFC.



2003 ◽  
Vol 82 (19) ◽  
pp. 3272-3274 ◽  
Author(s):  
B. D. Schrag ◽  
Gang Xiao


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