Comparative Investigation on Waste Heat Driven Air Supply Systems for PEM Fuel Cells

2016 ◽  
Author(s):  
Lili Yu ◽  
Weilin Zhuge ◽  
Yangjun Zhang ◽  
Jie Peng
Keyword(s):  
Fuel Cells ◽  
Fuel Cell ◽  
Waste Heat ◽  
Pem Fuel Cell ◽  
Pem Fuel Cells ◽  
Stoichiometric Ratio ◽  
Exhaust Gas ◽  
Supply Pressure ◽  
Air Supply ◽  
Supply Systems

The air supply system plays a key role for Proton Exchange Membrane (PEM) fuel cells. The performance of PEM fuel cells can be significantly improved by increasing the air supply pressure and air stoichiometric ratio. However, the increased electrical power consumption of the conventional motor driven air compressor operated at higher pressure would reduce the overall efficiency of the PEM fuel cell system. This paper proposes three novel air supply systems in which the compressor is driven by the waste heat recovered by the Organic Rankine Cycle (ORC) from the stack cooling water and the exhaust gas. The influences of air supply pressure and air stoichiometric ratio on the PEM fuel cell performance and exhaust gas are investigated through the fuel cell stack model. The performance analysis of the air supply system is carried out using a thermodynamic simulation model. And the proposed three air systems are compared to an air system driven by the exhaust gas and the assisted motor. Results show that both the air pressure and air stoichiometric ratio are improved significantly. The gross output electric power and the net efficiency of the PEM fuel cells are also improved greatly because of higher operating pressure and the elimination of the compressor power consumption. Among the 3 proposed air systems, the air system which has a self-circulation to maintain the stack temperature has the best performance and is most stable in operation.

scholarly journals High temperature PEM fuel cell steady-state transport modeling

2013 ◽  
Vol 24 (1) ◽  
pp. 55-60 ◽  
Author(s):  
Viorel Ionescu
Keyword(s):  
Fuel Cells ◽  
High Temperature ◽  
Fuel Cell ◽  
Proton Exchange Membrane ◽  
Waste Heat ◽  
Water Concentration ◽  
Pem Fuel Cell ◽  
Pem Fuel Cells ◽  
Proton Exchange ◽  
Electrochemical Kinetics

AbstractA fuel cell is a device that can directly transfer chemical energy to electric and thermal energy. Proton exchange membrane fuel cells (PEMFC) are highly efficient power generators, achieving up to 50-60% conversion efficiency, even at sizes of a few kilowatts. There are several compelling technological and commercial reasons for operating H2/air PEM fuel cells at temperatures above 100 °C; rates of electrochemical kinetics are enhanced, water management and cooling is simplified, useful waste heat can be recovered, and lower quality reformed hydrogen may be used as the fuel. All of the High Temperature PEMFC model equations are solved with finite element method using commercial software package COMSOL Multiphysics. The results from PEM fuel cell modeling were presented in terms of reactant (oxygen and hydrogen) concentrations and water concentration in the anode and cathode gases; the polarization curve of the cell was also displayed.

Analysis and Optimization of Transient Response of Polymer Electrolyte Fuel Cells

2015 ◽  
Vol 12 (1) ◽  
Author(s):  
A. Verma ◽  
R. Pitchumani
Keyword(s):  
Fuel Cells ◽  
Fuel Cell ◽  
Polymer Electrolyte ◽  
Transient Response ◽  
Single Channel ◽  
Rapid Change ◽  
Pem Fuel Cell ◽  
Pem Fuel Cells ◽  
Operating Parameters ◽  
Automotive Applications

Polymer electrolyte membrane (PEM) fuel cells are well suited for automotive applications compared to other types of fuel cells owing to their faster transient response and low-temperature operation. Due to rapid change in loads during automotive applications, study of dynamic behavior is of paramount importance. This study focuses on elucidating the transient response of a PEM fuel cell for specified changes in operating parameters, namely, voltage, pressure, and stoichiometry at the cathode and the anode. Transient numerical simulations are carried out for a single-channel PEM fuel cell to illustrate the response of power as the operating parameters are subjected to specified changes. These parameters are also optimized with an objective to match the power requirements of an automotive drive cycle over a certain period of time.

Artificial Neural Network Modeling of PEM Fuel Cells

2005 ◽  
Vol 2 (4) ◽  
pp. 226-233 ◽  
Author(s):  
Shaoduan Ou ◽  
Luke E. K. Achenie
Keyword(s):  
Neural Network ◽  
Artificial Neural Network ◽  
Fuel Cells ◽  
Fuel Cell ◽  
Back Propagation ◽  
Pem Fuel Cell ◽  
Pem Fuel Cells ◽  
Optimal Operating ◽  
Cell Systems ◽  
Artificial Neural

Artificial neural network (ANN) approaches for modeling of proton exchange membrane (PEM) fuel cells have been investigated in this study. This type of data-driven approach is capable of inferring functional relationships among process variables (i.e., cell voltage, current density, feed concentration, airflow rate, etc.) in fuel cell systems. In our simulations, ANN models have shown to be accurate for modeling of fuel cell systems. Specifically, different approaches for ANN, including back-propagation feed-forward networks, and radial basis function networks, were considered. The back-propagation approach with the momentum term gave the best results. A study on the effect of Pt loading on the performance of a PEM fuel cell was conducted, and the simulated results show good agreement with the experimental data. Using the ANN model, an optimization model for determining optimal operating points of a PEM fuel cell has been developed. Results show the ability of the optimizer to capture the optimal operating point. The overall goal is to improve fuel cell system performance through numerical simulations and minimize the trial and error associated with laboratory experiments.

Nonlinear Analysis of Two-Phase Instabilities in PEMFC Parallel-Channel Cathodes

2010 ◽  
Author(s):  
Nicholas Siefert ◽  
Chi-Hsin Ho ◽  
Shawn Litster
Keyword(s):  
Fuel Cells ◽  
Fuel Cell ◽  
Liquid Water ◽  
Proton Exchange Membrane ◽  
Critical Issue ◽  
Pem Fuel Cells ◽  
Proton Exchange ◽  
Stoichiometric Ratio ◽  
Two Phase ◽  
Voltage Loss

Liquid water management is a critical issue in the development of proton exchange membrane (PEM) fuel cells. Liquid water produced electrochemically can accumulate and flood the microchannels in the cathodes of PEM fuel cells. Since the liquid coverage of the cathode can fluctuate in time for two-phase flow, the rate of oxygen transport to the cathode catalyst layer can also fluctuate in time, and this can cause the fuel cell power output to fluctuate. This paper will report experimental data on the voltage loss and the voltage fluctuations of a PEM fuel cell due to flooding as a function of the number of parallel microchannels and the air flow rate stoichiometric ratio. The data was analyzed to identify general scaling relationships between voltage loss and fluctuations and the number of channels in parallel and the air stoichiometric ratio. The voltage loss was found to scale proportionally to the square root of the number of channels divided by the air stoichiometric ratio. The amplitude of the fluctuations was found to be linearly proportional to the number of microchannels and inversely proportional to the air stoichiometric ratio squared. The data was further analyzed by plotting power spectrums and by evaluating the non-linear statistics of the voltage time-series.

scholarly journals Effects of hydrogen relative humidity on the performance of an air-breathing PEM fuel cell

2019 ◽  
Vol 30 (4) ◽  
pp. 2077-2097 ◽  
Author(s):  
Zhenxiao Chen ◽  
Derek Ingham ◽  
Mohammed Ismail ◽  
Lin Ma ◽  
Kevin J. Hughes ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Fuel Cells ◽  
Fuel Cell ◽  
Relative Humidity ◽  
Pem Fuel Cell ◽  
Pem Fuel Cells ◽  
Air Breathing ◽  
Content Type ◽  
The Heat Transfer Coefficient

Purpose The purpose of this paper is to investigate the effects of hydrogen humidity on the performance of air-breathing proton exchange membrane (PEM) fuel cells. Design/methodology/approach An efficient mathematical model for air-breathing PEM fuel cells has been built in MATLAB. The sensitivity of the fuel cell performance to the heat transfer coefficient is investigated first. The effect of hydrogen humidity is also studied. In addition, under different hydrogen humidities, the most appropriate thickness of the gas diffusion layer (GDL) is investigated. Findings The heat transfer coefficient dictates the performance limiting mode of the air-breathing PEM fuel cell, the modelled air-breathing fuel cell is limited by the dry-out of the membrane at high current densities. The performance of the fuel cell is mainly influenced by the hydrogen humidity. Besides, an optimal cathode GDL and relatively thinner anode GDL are favoured to achieve a good performance of the fuel cell. Practical implications The current study improves the understanding of the effect of the hydrogen humidity in air-breathing fuel cells and this new model can be used to investigate different component properties in real designs. Originality/value The hydrogen relative humidity and the GDL thickness can be controlled to improve the performance of air-breathing fuel cells.

Advanced Integrated Flow Field (IFF) Design for High Performance Fuel Cell and Electrolyzer

2014 ◽  
Author(s):  
Michael Pien ◽  
Steven Lis ◽  
Radha Jalan ◽  
Marvin Warshay ◽  
Suresh Pahwa
Keyword(s):  
Fuel Cells ◽  
Fuel Cell ◽  
Flow Field ◽  
Gas Flow ◽  
Pem Fuel Cells ◽  
Water Flooding ◽  
Stoichiometric Ratio ◽  
Plant Design ◽  
Two Phase ◽  
Hydrophilic Matrix

Higher efficiency operation of PEM fuel cells needs an advanced passive way to remove product water. Water flooding in gas flow channels reduces efficiency and needs to be mitigated by a support of balance of plant design and components which results in parasitic power losses. ElectroChem’s Integrated Flow Field (IFF) design with the integration of hydrophobic and hydrophilic matrix has been proven to solve these challenges with no impact on the performance. The hydrophobic and hydrophilic matrix facilitates two phase (gas and liquid) flow to and away from the interface between the electrode membrane assembly and the flow field. A phase-separation feature of the IFF allowed the fuel cells to operate on a flow rate at its consumption rate. The IFF fuel cell has demonstrated operation at the ideal one stoichiometric ratio with 100% gas utilization and orientation independent. The IFF also served as gas humidifier through the creation of simultaneous distribution of gas and water within the cell. The self-humidification capability keeps the cell operating without the humidity of the input gas. The IFF design also enhanced the performance of water electrolysis which is a reverse process of fuel cell. The IFF supported the passive water feed to the cell and gas separation from the cell.

Alloys that form conductive and passivating oxides for proton exchange membrane fuel cell bipolar plates

2004 ◽  
Vol 19 (6) ◽  
pp. 1723-1729 ◽  
Author(s):  
Neil Aukland ◽  
Abdellah Boudina ◽  
David S. Eddy ◽  
Joseph V. Mantese ◽  
Margarita P. Thompson ◽  
...  
Keyword(s):  
Fuel Cells ◽  
Fuel Cell ◽  
Proton Exchange Membrane ◽  
Oxide Films ◽  
Pem Fuel Cell ◽  
Pem Fuel Cells ◽  
Proton Exchange ◽  
Bipolar Plates ◽  
Concentrated Solutions ◽  
Exchange Membrane

During the operation of proton exchange membrane (PEM) fuel cells, a high-resistance oxide is often formed on the cathode surface of base metal bipolar plates. Over time, this corrosion mechanism leads to a drop in fuel cell efficiency and potentially to complete failure. To address this problem, we have developed alloys capable of forming oxides that are both conductive and chemically stable under PEM fuel cell operating conditions. Five alloys of titanium with tantalum or niobium were investigated. The oxides were formed on the alloys by cyclic voltammetry in solutions mimicking the cathode- and anode-side environment of a PEM fuel cell. The oxides of all tested alloys had lower surface resistance than the oxide of pure titanium. We also investigated the chemical durability of Ti–Nb and Ti–Ta alloys in more concentrated solutions beyond those typically found in PEM fuel cells. The oxide films formed on Ti–Nb and Ti–Ta alloys remained conductive and chemically stable in these concentrated solutions. The stability of the oxide films was evaluated; Ti alloys having 3% Ta and Nb were identified as potential candidates for bipolar plate materials.

scholarly journals Transparent PEM Fuel Cells for Direct Visualisation Experiments

2009 ◽  
Author(s):  
M. I. Rosli ◽  
M. Pourkashanian ◽  
D. B. Ingham ◽  
L. Ma ◽  
D. Borman ◽  
...  
Keyword(s):  
Fuel Cells ◽  
Fuel Cell ◽  
Pem Fuel Cell ◽  
Pem Fuel Cells ◽  
Field Pattern ◽  
Cell Design ◽  
Serpentine Flow Field ◽  
Initial Work ◽  
Water Behavior ◽  
Visual Results

This paper reviews some of the previous research works on direct visualisation inside PEM fuel cells via a transparent single cell for the water behaviour investigation. Several papers which have employed the method have been selected and summarised and a comparison between the design of the cell, materials, methods and visual results are presented. The important aspects, advantages of the method and a summary on the previous work are discussed. Some initial work on transparent PEM fuel cell design using a single serpentine flow-field pattern is described. The results show that the direct visualisation via transparent PEM fuel cells could be one potential technique for investigating the water behavior inside the channels and a very promising way forward to provide useful data for validation in PEM fuel cell modelling and simulation.

Characterizing Performance of a PEM Fuel Cell for a CMET Balloon

2011 ◽  
Author(s):  
Denise A. McKahn ◽  
Whitney McMackin
Keyword(s):  
Fuel Cells ◽  
Fuel Cell ◽  
Mass Density ◽  
Pem Fuel Cell ◽  
Pem Fuel Cells ◽  
Cell Polarization ◽  
Operating Conditions ◽  
Design Parameters ◽  
Design System ◽  
Power Densities

We present the design of a multi-cell, low temperature PEM fuel cell for controlled meteorological balloons. Critical system design parameters that distinguish this application are the lack of reactant humidification and cooling due to the low power production, high required power mass-density and relatively short flight durations. The cell is supplied with a pressure regulated and dead ended anode, and flow controlled cathode at variable air stoichiometry. The cell is not heated and allowed to operate with unregulated temperature. Our prototype cell was capable of achieving power densities of 43 mW/cm2/cell or 5.4 mW/g. The cell polarization performance of large format PEM fuel cell stacks is an order of magnitude greater than for miniature PEM fuel cells. These performance discrepancies are a result of cell design, system architecture, and reactant and thermal management, indicating that there are significant gains to be made in these domains. We then present design modifications intended to enable the miniature PEM fuel cell to achieve power densities of 13 mW/g, indicating that additional performance gains must be made with improvements in operating conditions targeting achievable power densities of standard PEM fuel cells.

scholarly journals Experimental characterization of a PEM fuel cell for marine power generation

2022 ◽  
Vol 334 ◽  
pp. 05002
Author(s):  
Andrea Pietra ◽  
Marco Gianni ◽  
Nicola Zuliani ◽  
Stefano Malabotti ◽  
Rodolfo Taccani
Keyword(s):  
Power Generation ◽  
Fuel Cells ◽  
Energy Storage ◽  
Fuel Cell ◽  
Storage System ◽  
Pem Fuel Cell ◽  
Energy Storage System ◽  
Pem Fuel Cells ◽  
Power Converter ◽  
Plant Design

This study is focused on the possible application of hydrogen-fed PEM fuel cells on board ships. For this purpose, a test plant including a 100 kW generator suitable for marine application and a power converter including a supercapacitor-based energy storage system has been designed, built and experimentally characterised. The plant design integrates standard industrial components suitable for marine applications that include the technologies with the highest degree of maturity currently available on the market. Fuel Cell generator and power converter have been specifically designed by manufacturers to fit the specific plant needs. The experimental characterisation of the plant has been focused on the evaluation of the efficiency of the single components and of the overall system. Results shows a PEM fuel cell efficiency of 48% (when all auxiliaries are included) and an overall plant efficiency, including power conditioning, of about 45%. From load variation response tests, the fuel cell response time was maximum 2 seconds without supercapacitors and increased up to 20 seconds with supercapacitors connected, reducing the stress on the fuel cell generator. Experimental results confirm that PEM fuel cells, when supported by a suitably sized energy storage system, represent a viable technical solution for zero-emission power generation on board ships.

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