A Simple Thermal Model of PEM Fuel Cell Stacks

2004 ◽  
Author(s):  
B. Wetton ◽  
K. Promislow ◽  
A. C¸ag˘lar
Keyword(s):  
Fuel Cell ◽  
Temperature Distribution ◽  
Thermal Transport ◽  
Thermal Model ◽  
Cell Voltage ◽  
Membrane Electrode Assembly ◽  
Bipolar Plate ◽  
Membrane Resistance ◽  
Coolant Temperature ◽  
Membrane Electrode

A simple model is developed that determines the temperature distribution through a unit fuel cell with straight flow channels, in steady state operation. Using the large aspect ratio of the typical fuel cell geometry, the thermal model approximately decouples cross-plane thermal transport at each channel location. Using the fact that in-plane thermal conductivities are much larger than through-plane in typical bipolar plate construction, it is possible to further approximate the cross-plane thermal transport with a simple, one-dimensional model. We then consider the thermal coupling of several unit cells connected in series. In this way, we can simulate the effect of an anomalously hot cell in a stack environment. We take as inputs to the model the cell voltage and local current density, membrane resistance and condensation rates from a previously developed model. The thermal model outputs the average coolant temperature and the temperature distribution through the bipolar plates and membrane electrode assembly at each location down the channel. Although we are aware that there are significant coupling effects between the thermal distribution and performance, this is not taken into account in this study.

Ripple Current Effects on PEMFC Aging Test by Experimental and Modeling

2010 ◽  
Vol 8 (2) ◽  
Author(s):  
Mathias Gerard ◽  
Jean-Philippe Poirot-Crouvezier ◽  
Daniel Hissel ◽  
Marie-Cecile Péra
Keyword(s):  
Fuel Cell ◽  
High Frequency ◽  
Polymer Electrolyte Membrane ◽  
Cell Voltage ◽  
Membrane Electrode Assembly ◽  
Membrane Electrode ◽  
Local Conditions ◽  
Electrolyte Membrane ◽  
Aging Test ◽  
Dc Component

Polymer electrolyte membrane fuel cells’ (PEMFCs) systems usually require power conditioning by a dc-dc boost converter to increase the output fuel cell voltage, especially for automotive applications and stationary applications. The output fuel cell current is then submitted to the high frequency switching leading to a current ripple. The ripple current effects on fuel cell are studied by experimental ripple current aging test on a five cell stack (membrane electrode assembly (MEA) surface of 220 cm2) and compared with a reference aging test. The stack is run in nominal conditions but an ac component is added to the dc load. The ac component is a 5 kHz triangle, amplitude of which is ±20% of the dc component, in order to simulate a boost waveform. Fuel cell characterizations (polarization curves, impedance spectra, and voltammetry) provide information on the PEMFC aging and the performance evolution. Local conditions are computed through a dynamic stack model. The model takes into account transport phenomena, heat transfer, and semi-empirical electrochemical reactions and includes a meshing to calculate local conditions on the MEA surface (gas reactant pressures, local temperature, gas molar fractions, water activity, and local electronic current density). The consequences about performance and aging during high frequency ripple current are explained.

Effect of Channel Depth and Cell Temperature on the Performance of a Direct Methanol Fuel Cell

2013 ◽  
Vol 10 (3) ◽  
Author(s):  
Ebrahim Alizadeh ◽  
Mousa Farhadi ◽  
Kurosh Sedighi ◽  
Mohsen Shakeri
Keyword(s):  
Fuel Cell ◽  
Direct Methanol Fuel Cell ◽  
Membrane Electrode Assembly ◽  
Bipolar Plate ◽  
Cell Performance ◽  
Membrane Electrode ◽  
Channel Depth ◽  
Direct Methanol ◽  
Pt Black ◽  
Methanol Fuel Cell

The main goal of this study is to analyze the performance of the direct methanol single cell using three channel depths at various cell temperatures. The membrane electrode assembly (MEA) used Nafion® 117, by loading a Pt-Ru (4 mg/cm2) catalyst at the anode and Pt-black (4 mg/cm2) catalyst at the cathode. The active area of the MEA was 100 cm (Jung et al., 2009, “Investigation of Flow Bed Design in Direct Methanol Fuel Cell,” J. Solid State Electrochem., 13, pp. 1455–1465). In these sets of experiments, anode and cathode channel depth were varied simultaneously. The cell performance is improved with an increase of temperature in a certain range because the conductivity of the membrane and the reaction kinetics at both the anode and cathode are increased. Also, when the channel depth of the bipolar plate is decreased from 2.0 to 1.0 mm, the cell performance increases. The decreased channel depth leads to an increase in the linear velocity of reactants and products.

scholarly journals Effect of Friction Coefficient on Relative Slippage of Fuel Cell Stack under Mechanical Impact Condition

2018 ◽  
Vol 2018 ◽  
pp. 1-8
Author(s):  
Yongping Hou ◽  
Leiqi Wang ◽  
Jianwen Zhang ◽  
Dong Hao
Keyword(s):  
Fuel Cell ◽  
Friction Coefficient ◽  
Three Dimensional ◽  
Element Model ◽  
Membrane Electrode Assembly ◽  
Bipolar Plate ◽  
Membrane Electrode ◽  
Three Dimensional Model ◽  
Impact Acceleration ◽  
Relative Slippage

A simplified finite element model for large polymer electrolyte membrane fuel cell (PEMFC) stack consisting of ten cells is established in order to investigate the internal structure deformation. It is found that the interface slippage occurs when the bipolar plate (BP) and membrane electrode assembly (MEA) are subjected to vertical impact acceleration. Based on this three-dimensional model, the influence of the friction coefficient between BP and MEA on the relative slippage can be analyzed efficiently. The division layer of relative slippage is found and its vibration rule is discussed. It is observed that increasing the magnitude of impact vibration has most significant effect on the movement of the division layer, and the two variables are linearly related when impact acceleration is greater than 5 g. This work provides important insight into the choice of the friction coefficient.

Electrically Conductive CNT/PTFE Composite Film for Corrosion Resistant Coating on Bipolar Plate of Fuel Cell

2009 ◽  
Vol 1204 ◽  
Author(s):  
Yoshiyuki Show ◽  
K. Takahashi ◽  
R. Nishimura ◽  
K. Kohara ◽  
Y. Fukami ◽  
...  
Keyword(s):  
Fuel Cell ◽  
Composite Film ◽  
Polymer Electrolyte Membrane ◽  
Membrane Electrode Assembly ◽  
Bipolar Plate ◽  
Membrane Electrode ◽  
Electrically Conductive ◽  
Corrosion Resistant ◽  
Electrolyte Membrane ◽  
Conductive Film

AbstractComposite film of carbon nanotube (CNT) and polytetrafluoroethylene (PTFE) was formed with despersion fluid of CNT and PTFE. The film showed high electrical conductivity in the range of 5-13S/cm. This conductive film was applied on the stainless steel bipolar plate for the polymer electrolyte membrane fuel cell (PEMFC) as anticorrosion film. This coating decreased the contact resistance between the surface of bipolar plate and the membrane electrode assembly (MEA) of the PEMFC. Therefore, the output power of the fuel cell was increased by 1.6 times.

In Situ Temperature Distribution Measurement in an Operating Polymer Electrolyte Fuel Cell

2003 ◽  
Author(s):  
Matthew M. Mench ◽  
Daniel J. Burford ◽  
Tyler W. Davis
Keyword(s):  
Fuel Cell ◽  
Temperature Distribution ◽  
Polymer Electrolyte ◽  
Membrane Electrode Assembly ◽  
Polymer Electrolyte Fuel Cell ◽  
Membrane Electrode ◽  
Two Phase ◽  
Temperature Distribution Measurement ◽  
Current Densities

The temperature distribution in a polymer electrolyte fuel cell (PEFC) is of critical importance to the water balance, as well as to other kinetic and transport phenomena that are known to be functionally dependent on temperature. However, direct measurement of localized temperature is difficult, due to the two-phase nature of flow in the gas channels and the small through-plane dimensions of a typical electrolyte. To circumvent these difficulties, an array of microthermocouples was embedded directly between two 25 μm thick Nation™ electrolyte sheets of a membrane electrode assembly. The embedded array was used to measure electrolyte temperature as a function of current and fuel cell flow channel location. For the fuel cell tested with natural convective cooling, a temperature increase in the electrolyte of as much as 15°C is observed for current densities of 1 A/cm2.

Catalytic layer-membrane electrode assembly methods for optimum triple phase boundaries and fuel cell performances

2021 ◽  
Author(s):  
Imen Fouzaï ◽  
Solène Gentil ◽  
Victor Costa Bassetto ◽  
Wanderson Oliveira Silva ◽  
Raddaoui Maher ◽  
...  
Keyword(s):  
Fuel Cell ◽  
Membrane Electrode Assembly ◽  
Emerging Technology ◽  
Membrane Electrode ◽  
Catalytic Layer ◽  
Phase Boundaries ◽  
Layer Membrane ◽  
Critical Overview

A critical overview of MEA fabrication techniques is given focusing on the formation of triple phase boundaries, known for increasing PEMFC performances. Print-light-synthesis is a new emerging technology to achieve nanostructred MEA.

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