scholarly journals Short Circuit Characteristics of PEM Fuel Cells for Grid Integration Applications

Electronics ◽  
2020 ◽  
Vol 9 (4) ◽  
pp. 602 ◽  
Author(s):  
Florian Grumm ◽  
Marc Schumann ◽  
Carsten Cosse ◽  
Maik Plenz ◽  
Arno Lücken ◽  
...  
Keyword(s):  
Fuel Cells ◽  
Fuel Cell ◽  
Power Supply ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Pem Fuel Cells ◽  
Pollutant Emissions ◽  
Carbon Cloth ◽  
Grid Integration ◽  
Emergency Power

The reduction of greenhouse gas and pollutant emissions is a major issue in modern society. Therefore, environmentally friendly technologies like fuel cells should replace conventional energy generation plants. Today, fuel cells are used in households for CHP (combined heat and power) applications, for emergency power supply in many stationary applications and for the power supply of cars, buses and ships and emergency power supply of aircrafts. A significant challenge is the optimal electrical grid integration and selection of the appropriate grid protection mechanism for fuel cell applications. For this, the short circuit capability and behavior needs to be known. This paper gives a mathematical estimation of the short circuit behavior of fuel cells. Five main transient and dynamic phenomena are investigated. The impact of the main transient effect for the provision of additional short circuit energy is simulated, and the simulation is experimentally validated. For this purpose, a 25 c m 2 single cell consisting of a NafionTM 212 membrane and carbon cloth electrodes with a catalyst loading of 0 . 5 m g / c m 2 Pt is analyzed. The magnitude of the transient short circuit current depends on the operating point right before the short circuit occurs, whereas the stationary short circuit current of fuel cells is invariably about twice the operational current. Based on these results, a novel fuel cell model for the estimation of the short circuit behavior is proposed.

scholarly journals Experimental Studies of Effect of Land Width in PEM Fuel Cells with Serpentine Flow Field and Carbon Cloth

Energies ◽  
2019 ◽  
Vol 12 (3) ◽  
pp. 471 ◽  
Author(s):  
Xuyang Zhang ◽  
Andrew Higier ◽  
Xu Zhang ◽  
Hongtan Liu
Keyword(s):  
Fuel Cells ◽  
Fuel Cell ◽  
Flow Field ◽  
Pem Fuel Cells ◽  
Carbon Cloth ◽  
Pumping Power ◽  
Inlet Flow ◽  
Flow Rates ◽  
Reactant Flow ◽  
Land Width

Flow field plays an important role in the performance of proton exchange membrane (PEM) fuel cells, such as transporting reactants and removing water products. Therefore, the performance of a PEM fuel cell can be improved by optimizing the flow field dimensions and designs. In this work, single serpentine flow fields with four different land widths are used in PEM fuel cells to study the effects of the land width. The gas diffusion layers are made of carbon cloth. Since different land widths may be most suitable for different reactant flow rates, three different inlet flow rates are studied for all the flow fields with four different land widths. The effects of land width and inlet flow rate on fuel cell performance are studied based on the polarization curves and power densities. Without considering the pumping power, the cell performance always increases with the decrease in the land width and the increase in the inlet flow rates. However, when taking into consideration the pumping power, the net power density reaches the maximum at different combinations of land widths and reactant flow rates at different cell potentials.

Novel Approaches for the Integration of High Temperature PEM Fuel Cells Into Aircrafts

2010 ◽  
Author(s):  
Eva Novillo ◽  
Mo´nica Pardo ◽  
Alberto Garci´a-Luis
Keyword(s):  
Fuel Cells ◽  
High Temperature ◽  
Fuel Cell ◽  
Elevated Temperatures ◽  
Pem Fuel Cells ◽  
Chemical Degradation ◽  
Unit Weight ◽  
Optimum Operating ◽  
Short Term ◽  
Emergency Power

Reduced greenhouse gas emissions via improved energy efficiency represents the ultimate challenge for the energy economy of the future. In this context, fuel cells for power generation aboard aircrafts have a promising potential to effectively contribute to the greening of air transportation. They can simplify today’s aircraft comprising electric, pneumatic and hydraulic systems towards a more electric airplane. Although they are not considered in the short term as an alternative propulsion system for commercial aviation, many efforts are being devoted to their use as auxiliary power units and even aiming to build a distributed power network that might alleviate duties of the engine driven generators. In addition they allow new functions as zero emission during taxiing on ground and /or increase safety by replacing the emergency ram air turbine (RAT) by a fuel cell based emergency power generator. The present paper focuses on the effort that Compan˜i´a Espan˜ola de Sistemas Aerona´uticos (CESA) is putting into the development of an aeronautical fuel cell system based on a high temperature PEMFC covering all aspects from fundamental research in materials & processes to final integration concepts as a function of different architectures. A great deal of time and effort has been invested to overcome the challenges of PEM fuel cell operation at high temperatures. Among the advantages of these systems are the enhancement of electrochemical kinetics, simplification of water management and cooling, recovery of wasted heat and the possibility of utilizing reformed hydrogen thanks to higher tolerance to impurities. However, new problems arise with the high temperature concept that must be addressed like structural and chemical degradation of materials at elevated temperatures. One of the aeronautical applications where a fuel cell has an important role to play in the short term is the emergency power unit. Weight and mechanical complexity of traditional ram air turbines could be drastically reduced by the introduction of a hydrogen fueled system. In addition, the output of the fuel cell is aircraft’s speed independent. This means additional power supply in case of emergency allowing a safer landing of the aircraft. However, a RAT replacement must overcome the specific difficulties concerning the very short start-up times allowed and the heating/cooling strategies to quickly raise the temperature to elevated levels and accurately maintaining the optimum operating range once in service.

scholarly journals Use of Electrochemical Impedance Spectroscopy for the Evaluation of Performance of PEM Fuel Cells Based on Carbon Cloth Gas Diffusion Electrodes

2018 ◽  
Vol 2018 ◽  
pp. 1-13 ◽  
Author(s):  
Saverio Latorrata ◽  
Renato Pelosato ◽  
Paola Gallo Stampino ◽  
Cinzia Cristiani ◽  
Giovanni Dotelli
Keyword(s):  
Fuel Cells ◽  
Electrochemical Impedance Spectroscopy ◽  
Fuel Cell ◽  
Impedance Spectroscopy ◽  
Current Density ◽  
Electrochemical Impedance ◽  
Pem Fuel Cells ◽  
Gas Diffusion ◽  
Carbon Cloth ◽  
Gas Diffusion Electrodes

Polymer electrolyte membrane fuel cells (PEMFCs) have attracted great attention in the last two decades as valuable alternative energy generators because of their high efficiencies and low or null pollutant emissions. In the present work, two gas diffusion electrodes (GDEs) for PEMFCs were prepared by using an ink containing carbon-supported platinum in the catalytic phase which was sprayed onto a carbon cloth substrate. Two aerograph nozzles, with different sizes, were used. The prepared GDEs were assembled into a fuel cell lab prototype with commercial electrolyte and bipolar plates and tested alternately as anode and cathode. Polarization measurements and electrochemical impedance spectroscopy (EIS) were performed on the running hydrogen-fed PEMFC from open circuit voltage to high current density. Experimental impedance spectra were fitted with an equivalent circuit model by using ZView software which allowed to get crucial parameters for the evaluation of fuel cell performance, such as ohmic resistance, charge transfer, and mass transfer resistance, whose trends have been studied as a function of the applied current density.

Novel Approaches for the Integration of High Temperature PEM Fuel Cells Into Aircrafts

2010 ◽  
Vol 8 (1) ◽  
Author(s):  
Eva Novillo ◽  
Mónica Pardo ◽  
Alberto García-Luis
Keyword(s):  
Fuel Cells ◽  
High Temperature ◽  
Fuel Cell ◽  
Elevated Temperatures ◽  
Pem Fuel Cells ◽  
Chemical Degradation ◽  
Unit Weight ◽  
Optimum Operating ◽  
Short Term ◽  
Emergency Power

Reduced greenhouse gas emissions via improved energy efficiency represent the ultimate challenge for the energy economy of the future. In this context, fuel cells for power generation aboard aircrafts have a promising potential to effectively contribute to the greening of air transportation. They can simplify today’s aircraft comprising electric, pneumatic, and hydraulic systems toward a more electric airplane. Although they are not considered in the short term as an alternative propulsion system for commercial aviation, many efforts are being devoted to their use as auxiliary power units and even aiming to build a distributed power network that might alleviate duties of the engine driven generators. In addition they allow new functions such as zero emission during taxiing on ground and/or increase safety by replacing the emergency ram-air turbine (RAT) by a fuel cell based emergency power generator. The present paper focuses on the effort that Compañía Española de Sistemas Aeronáuticos (CESA) is putting into the development of an aeronautical fuel cell system based on a high-temperature PEMFC covering all aspects from fundamental research in materials and processes to final integration concepts as a function of different architectures. A great deal of time and effort has been invested to overcome the challenges of PEM fuel cell operation at high temperatures. Among the advantages of these systems are the enhancement of electrochemical kinetics, the simplification of water management and cooling, the recovery of wasted heat, and the possibility of utilizing reformed hydrogen thanks to higher tolerance to impurities. However, new problems arise with the high-temperature concept that must be addressed such as structural and chemical degradation of materials at elevated temperatures. One of the aeronautical applications, where a fuel cell has an important role to play in the short term is the emergency power unit. Weight and mechanical complexity of traditional ram-air turbines could be drastically reduced by the introduction of a hydrogen fueled system. In addition, the output of the fuel cell is aircraft’s speed independent. This means additional power supply in case of emergency allowing a safer landing of the aircraft. However, a RAT replacement must overcome the specific difficulties concerning the very short start-up times allowed and the heating/cooling strategies to quickly raise the temperature to elevated levels and accurately maintaining the optimum operating range once in service.

PVD Coated Bipolar Plates for PEM Fuel Cells

2005 ◽  
Vol 2 (4) ◽  
pp. 290-294 ◽  
Author(s):  
Shuo-Jen Lee ◽  
Ching-Han Huang ◽  
Yu-Pang Chen ◽  
Chen-Te Hsu
Keyword(s):  
Corrosion Resistance ◽  
Fuel Cells ◽  
Fuel Cell ◽  
Physical Vapor Deposition ◽  
Corrosion Current ◽  
Pem Fuel Cells ◽  
Bipolar Plates ◽  
Coating Materials ◽  
Pvd Coating ◽  
Simulated Fuel

Aluminum was considered a good candidate material for bipolar plates of the polymer electrolyte membrane (PEM) fuel cells due to its low cost, light weight, high strength and good manufacturability. But there were problems of both chemical and electrochemical corrosions in the PEM fuel cell operating environment. The major goals of this research are to find proper physical vapor deposition (PVD) coating materials which would enhance surface properties by making significant improvements on corrosion resistance and electrical conductivity at a reasonable cost. Several coating materials had been studied to analyze their corrosion resistance improvement. The corrosion rates of all materials were tested in a simulated fuel cell environment. The linear polarization curve of electrochemical method measured by potentiostat instrument was employed to determine the corrosion current. Results of the corrosion tests indicated that all of the coating materials had good corrosion resistance and were stable in the simulated fuel cell environment. The conductivities of the coated layers were better and the resistances changed very little after the corrosion test. At last, single fuel cells were made by each PVD coating material. Fuel cell tests were conducted to determine their performance w.r.t. that was made of graphite. The results of fuel cell tests indicated that metallic bipolar plates with PVD coating could be used in PEM fuel cells.

scholarly journals Optimal Synergy between Photovoltaic Panels and Hydrogen Fuel Cells for Green Power Supply of a Green Building—A Case Study

2021 ◽  
Vol 13 (11) ◽  
pp. 6304
Author(s):  
Raluca-Andreea Felseghi ◽  
Ioan Așchilean ◽  
Nicoleta Cobîrzan ◽  
Andrei Mircea Bolboacă ◽  
Maria Simona Raboaca
Keyword(s):  
Carbon Dioxide ◽  
Fuel Cells ◽  
Fuel Cell ◽  
Power Supply ◽  
Carbon Dioxide Emissions ◽  
Green Building ◽  
Energy System ◽  
Generation System ◽  
Photovoltaic Panels

Alternative energy resources have a significant function in the performance and decarbonization of power engendering schemes in the building application domain. Additionally, “green buildings” play a special role in reducing energy consumption and minimizing CO2 emissions in the building sector. This research article analyzes the performance of alternative primary energy sources (sun and hydrogen) integrated into a hybrid photovoltaic panel/fuel cell system, and their optimal synergy to provide green energy for a green building. The study addresses the future hydrogen-based economy, which involves the supply of hydrogen as the fuel needed to provide fuel cell energy through a power distribution infrastructure. The objective of this research is to use fuel cells in this field and to investigate their use as a green building energy supply through a hybrid electricity generation system, which also uses photovoltaic panels to convert solar energy. The fuel cell hydrogen is supplied through a distribution network in which hydrogen production is outsourced and independent of the power generation system. The case study creates virtual operating conditions for this type of hybrid energy system and simulates its operation over a one-year period. The goal is to demonstrate the role and utility of fuel cells in virtual conditions by analyzing energy and economic performance indicators, as well as carbon dioxide emissions. The case study analyzes the optimal synergy between photovoltaic panels and fuel cells for the power supply of a green building. In the simulation, an optimally configured hybrid system supplies 100% of the energy to the green building while generating carbon dioxide emissions equal to 11.72% of the average value calculated for a conventional energy system providing similar energy to a standard residential building. Photovoltaic panels account for 32% of the required annual electricity production, and the fuel cells generate 68% of the total annual energy output of the system.

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.

Effect of Vibration on the Liquid Water Transport of PEM Fuel Cells

2009 ◽  
Author(s):  
Luis Breziner ◽  
Peter Strahs ◽  
Parsaoran Hutapea
Keyword(s):  
Fuel Cells ◽  
Fuel Cell ◽  
Water Transport ◽  
Liquid Water ◽  
Pem Fuel Cells ◽  
Gas Diffusion ◽  
Cell Performance ◽  
Sinusoidal Vibration ◽  
Fuel Cell Performance ◽  
Liquid Water Transport

The objective of this research is to analyze the effects of vibration on the performance of hydrogen PEM fuel cells. It has been reported that if the liquid water transport across the gas diffusion layer (GDL) changes, so does the overall cell performance. Since many fuel cells operate under a vibrating environment –as in the case of automotive applications, this may influence the liquid water concentration across the GDL at different current densities, affecting the overall fuel cell performance. The problem was developed in two main steps. First, the basis for an analytical model was established using current models for water transport in porous media. Then, a series of experiments were carried, monitoring the performance of the fuel cell for different parameters of oscillation. For sinusoidal vibration at 10, 20 and 50Hz (2 g of magnitude), a decrease in the fuel cell performance by 2.2%, 1.1% and 1.3% was recorded when compared to operation at no vibration respectively. For 5 g of magnitude, the fuel cell reported a drop of 5.8% at 50 Hz, whereas at 20 Hz the performance increased by 1.3%. Although more extensive experimentation is needed to identify a relationship between magnitude and frequency of vibration affecting the performance of the fuel cell as well as a throughout examination of the liquid water formation in the cathode, this study shows that sinusoidal vibration, overall, affects the performance of PEM fuel cells.

Computer Models of Pem Fuel Cells for the Study of Transient Modes in Electrical Power Supply Complexes

2021 ◽  
Vol 64 (3) ◽  
pp. 60-67
Author(s):  
Ivan Vasyukov ◽  
Keyword(s):  
Fuel Cells ◽  
Fuel Cell ◽  
Dynamic Response ◽  
Gradient Descent ◽  
Eddy Currents ◽  
Least Squares Method ◽  
Electrical Power ◽  
Computer Models ◽  
Pem Fuel Cells ◽  
Current Voltage

Static and dynamic computer models of fuel cells are considered. A static model is determined that most ac-curately reproduces the current-voltage characteristic of a real fuel cell. A method for tuning it according to the experimental I - V characteristic by the least squares method is proposed. A method for its adjustment ac-cording to the experimental I - V characteristic by the method of gradient descent is proposed. A modified elec-trical equivalent circuit of a fuel cell has been developed, which simulates its dynamic response, taking into ac-count the damping effect of eddy currents during operation of a stack of fuel cells on a pulse voltage converter. A method is proposed for determining the parameters of the model from the experimental oscillograms of the current and voltage of the stack. A universal model of a stack of fuel cells in LTspice has been developed, which makes it possible to simulate a dynamic response and, if necessary, simulate a real static I – V characteristic of the stack.

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