Transient Analysis of Gas Distribution in the Anodic Flow Field in a Fuel Cell Stack

2013 ◽  
Author(s):  
Yasushi Ichikawa ◽  
Nobuyuki Oshima
Keyword(s):  
Fuel Cells ◽  
Fuel Cell ◽  
Flow Field ◽  
Polymer Electrolyte Fuel Cell ◽  
Gas Distribution ◽  
Fuel Cell Stack ◽  
Analysis Experiment ◽  
Hydrogen Supply ◽  
Cathodic Side ◽  
Anodic Side

In a polymer electrolyte fuel cell (PEFC), the catalyst degradation on cathodic side is one of the fatal problems caused by mal-distributed hydrogen supply into each channel on active area in a fuel cell, especially in a fuel cell stack for automotive fuel cell systems which consist of several hundreds of fuel cells stacked. For example, before getting the fuel cell system started-up, the gas in all the anodic flow passage including channels in each fuel cell is occupied by air instead of hydrogen due to cross leak from cathodic side to anodic side through the membrane employed as an electrolyte. In this situation, if hydrogen is supplied partially or unevenly between cells to start up the system, a concentration interface of air and hydrogen will be made within a fuel cell. This causes a state of local cell within a single fuel cell and the catalyst degradation (carbon corrosion or Pt dissolution) occurs. In this paper, to avoid this catalyst degradation, the gas distribution is investigated with pressurized hydrogen supply into channels located on the hundreds stacked fuel cells statically filled with air initially. A transient computational fluid analysis was applied to the flow fields of anodic side which consist of channels on fuel cells, both distributing and collecting manifold connected to the fuel cells under parameters: 1) number of stacked fuel cells (i.e. manifold length), 2) the rate of pressure rising (Pa/sec.) which makes the gas flow velocity. A gas analysis experiment was also carried out for a validation with mass spectrometer taking gas sample from several points along the gas channels on alternative fuel cells which are made of transparent acrylic resin. The results show that the uniform distribution in concentration between cells and its profile within the channels along the flow direction are strongly affected by flow field formed within the distributing manifold located upstream of stacked plates with channels.

Review of Materials and Characterization Methods for Polymer Electrolyte Fuel Cell Flow-Field Plates

2006 ◽  
Vol 4 (1) ◽  
pp. 29-44 ◽  
Author(s):  
Daniel J. L. Brett ◽  
Nigel P. Brandon
Keyword(s):  
Fuel Cell ◽  
Flow Field ◽  
Polymer Electrolyte ◽  
Polymer Electrolyte Fuel Cell ◽  
Characterization Methods ◽  
Fuel Cell Stack ◽  
Field Plate ◽  
And Performance ◽  
The Cost

The role of the flow-field plate is of major importance in determining the performance of a polymer electrolyte fuel cell. The flow-field plate constitutes the largest volumetric and gravimetric proportion of the fuel cell stack and has a strong bearing on the cost and efficiency of the system. This review considers the materials being used to make flow-field plates and the methods used to characterize materials properties and performance.

Analytical and numerical study on cooling flow field designs performance of PEM fuel cell with variable heat flux

2016 ◽  
Vol 30 (16) ◽  
pp. 1650155 ◽  
Author(s):  
Ebrahim Afshari ◽  
Masoud Ziaei-Rad ◽  
Nabi Jahantigh
Keyword(s):  
Heat Flux ◽  
Fuel Cells ◽  
Fuel Cell ◽  
Pressure Drop ◽  
Flow Field ◽  
Pem Fuel Cells ◽  
Coolant Flow ◽  
Temperature Uniformity ◽  
Variable Heat ◽  
Variable Heat Flux

In PEM fuel cells, during electrochemical generation of electricity more than half of the chemical energy of hydrogen is converted to heat. This heat of reactions, if not exhausted properly, would impair the performance and durability of the cell. In general, large scale PEM fuel cells are cooled by liquid water that circulates through coolant flow channels formed in bipolar plates or in dedicated cooling plates. In this paper, a numerical method has been presented to study cooling and temperature distribution of a polymer membrane fuel cell stack. The heat flux on the cooling plate is variable. A three-dimensional model of fluid flow and heat transfer in cooling plates with 15 cm × 15 cm square area is considered and the performances of four different coolant flow field designs, parallel field and serpentine fields are compared in terms of maximum surface temperature, temperature uniformity and pressure drop characteristics. By comparing the results in two cases, the constant and variable heat flux, it is observed that applying constant heat flux instead of variable heat flux which is actually occurring in the fuel cells is not an accurate assumption. The numerical results indicated that the straight flow field model has temperature uniformity index and almost the same temperature difference with the serpentine models, while its pressure drop is less than all of the serpentine models. Another important advantage of this model is the much easier design and building than the spiral models.

scholarly journals Propriedades físico-químicas relacionadas ao desenvolvimento de membranas de Nafion® para aplicações em células a combustível do tipo PEMFC

Polímeros ◽  
2008 ◽  
Vol 18 (4) ◽  
pp. 281-288 ◽  
Author(s):  
Carlos E. Perles
Keyword(s):  
Fuel Cells ◽  
Fuel Cell ◽  
Polymer Electrolyte ◽  
Polymer Electrolyte Fuel Cell

Embora não seja tecnologia recente, as células a combustível ou Fuel Cells (FC) continuam recebendo grande atenção, pois são consideradas como "fontes de energia do futuro" devido a características como alto rendimento energético e baixa emissão de poluentes, permitindo a extensão o tempo de vida das reservas fósseis e contribuindo para a melhoria da qualidade de vida. Atualmente, as pesquisas estão direcionadas, principalmente, ao desenvolvimento de FC para aplicações em sistemas móveis e portáteis. De todas as tecnologias existentes, a mais promissora para essa finalidade é a célula a combustível de eletrólito polimérico, conhecida como PEMFC (Polymer Electrolyte Fuel Cell) cuja pesquisa encontra-se focada, principalmente, no desenvolvimento de membranas poliméricas, com o objetivo de reduzir os custos de produção. Este trabalho será focado nos aspectos físico-químicos do desenvolvimento de membranas poliméricas. Serão discutidos aspectos estruturais do Nafion® relacionado-os as seguintes propriedades físico-químicas: fluxo eletrosmótico, permeabilidade gasosa, transporte de água através da membrana, estabilidade química e térmica. Toda a discussão será realizada para polímeros perfluorados, utilizando o Nafion® como modelo representante dessa classe de polímeros.

Numerical Studies of Heat Transport for Polymer Electrolyte Fuel Cell Stack in Sub-Freezing Environment

2009 ◽  
Author(s):  
Pengtao Sun ◽  
Su Zhou
Keyword(s):  
Heat Transfer ◽  
Fuel Cell ◽  
Polymer Electrolyte ◽  
Heat Transport ◽  
Numerical Solutions ◽  
Polymer Electrolyte Fuel Cell ◽  
Fuel Cell Stack ◽  
Finite Volume Discretization ◽  
Heat Transport Equation ◽  
Heating Up

Two cases of heat transfer processes for a general polymer electrolyte fuel cell (PEFC) stack in a sub-freezing environment are studied in this paper: cooling-down and heating-up. We investigate the time consumption problem for both of these two cases in order to find the way to normally restart fuel cell stack without regard to electrochemical reaction. We consider the action of heat transfer in lieu of generated chemical energy to PEFC in sub-freezing environment by means of heat insulator. In the numerical simulation, we define a combined finite element/upwind finite volume discretization to approximate the heat transport equation for different cases of heat transport process, and obtain the stable and reasonable numerical solutions. These results correspondingly provide explicit ways to preserve heat in PEFC stack in the sub-freezing environment.

Study of an Innovative Versatile Flow Design Suitable for Fuel Cells

2017 ◽  
Vol 14 (4) ◽  
Author(s):  
S. Meenakshi ◽  
Prakash C. Ghosh
Keyword(s):  
Fuel Cells ◽  
Flow Field ◽  
Flow Distribution ◽  
Polymer Electrolyte Fuel Cell ◽  
Cathode Side ◽  
Flow Mode ◽  
Hybrid Mode ◽  
Large Area ◽  
Dead End ◽  
A Current

Flow field plays an important role in the performances of the fuel cells, especially in large area fuel cells. In the present work, an innovative, versatile flow field, capable of combining in different conventional modes is reported and evaluated in a polymer electrolyte fuel cell (PEFC) with an active area of 150 cm2. The proposed design is capable of offering serpentine, interdigitated, counterflow, dead-end, and serpentine-interdigitated hybrid mode. Moreover, it is possible to switch over from one flow mode to another mode of flow during operation at any point of time. The flow design consists of the multichannel parallel serpentine flow (SP) field and a pair of an inlet and outlet manifolds instead of conventional single inlet and outlet manifold. Flow distribution was successfully altered without affecting the performances, and it was observed a combination of serpentine and interdigitated on the cathode side offered steady performance for more than 20 min when it was operated at a current density of 700 mA cm−2.

Overview of Field Performance by UTC Fuel Cells’ Transportation Fuel-Cell Power Plants

2005 ◽  
Author(s):  
Praveen Narasimhamurthy ◽  
Zakiul Kabir
Keyword(s):  
Fuel Cells ◽  
Fuel Cell ◽  
Power Plants ◽  
Ambient Pressure ◽  
Polymer Electrolyte Membrane ◽  
Field Performance ◽  
Pem Fuel Cell ◽  
Low Noise ◽  
Transportation Fuel ◽  
Fuel Cell Stack

UTC Fuel Cells (UTCFC) over the last few years has partnered with leading automotive and bus companies and developed Polymer Electrolyte Membrane (PEM) fuel-cell power plants for various transportation applications, for instance, automotive, buses, and auxiliary power units (APUs). These units are deployed in various parts of the globe and have been gaining field experience under both real world and laboratory environments. The longest running UTC PEM fuel cell stack in a public transport bus has accumulated over 1350 operating hours and 400 start-stop cycles. The longest running APU fuel cell stack has accrued over 3000 operating hours with more than 3200 start-stop cycles. UTCFC PEM fuel-cell systems are low noise and demonstrate excellent steady state, cyclic, and transient capabilities. These near ambient pressure, PEMFC systems operate at high electrical efficiencies at both low and rated power conditions.

Polymer electrolyte membrane fuel cell flow field designs and approaches for performance enhancement

2019 ◽  
Vol 234 (8) ◽  
pp. 1189-1214 ◽  
Author(s):  
Erman Çelik ◽  
İrfan Karagöz
Keyword(s):  
Fuel Cells ◽  
Fuel Cell ◽  
Flow Field ◽  
Polymer Electrolyte ◽  
Polymer Electrolyte Membrane ◽  
High Energy ◽  
Cell Performance ◽  
High Energy Density ◽  
Field Development ◽  
Electrolyte Membrane

Polymer electrolyte membrane fuel cells are carbon-free electrochemical energy conversion devices that are appropriate for use as a power source on vehicles and mobile devices emerging with their high energy density, lightweight structure, quick startup and lower operating temperature capabilities. However, they need more developments in the aspects of reactant distribution, less pressure drops, precisely balanced water content and heat management to achieve more reliable and higher overall cell performance. Flow field development is one of the most important fields of study to increase cell performance since it has decisive effects on performance parameters, including bipolar plate, and thus fuel cell weight. In this study, recent developments on conventional flow field designs to eliminate their weaknesses and innovative design approaches and flow field architectures are obtained from patent databases, and both numerical and experimental scientific studies. Fundamental designs that create differences are introduced, and their effects on the performance are discussed with regard to origin, objective, innovation strategy of design besides their strength and probable open development ways. As a result, significant enhancements and design strategies on flow field designs in polymer electrolyte membrane fuel cells are summarized systematically to guide prospective flow field development studies.

Measurement of deuterium isotope separation by polymer electrolyte fuel cell stack

2019 ◽  
Vol 44 (3) ◽  
pp. 1851-1856 ◽  
Author(s):  
Risako Tanii ◽  
Ryota Ogawa ◽  
Hisayoshi Matsushima ◽  
Mikito Ueda
Keyword(s):  
Fuel Cell ◽  
Polymer Electrolyte ◽  
Isotope Separation ◽  
Polymer Electrolyte Fuel Cell ◽  
Fuel Cell Stack
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