Dynamic Modelling and Controls of an Air Supply System for In-Flight Proton Exchange Membrane Fuel Cells (PEM-FC)

2007 ◽  
Author(s):  
Lukas P. Barchewitz ◽  
Joerg R. Seume
Keyword(s):  
Fuel Cells ◽  
Fuel Cell ◽  
Power Density ◽  
Supply System ◽  
Operating Conditions ◽  
Design Parameters ◽  
Radial Turbine ◽  
Air Supply ◽  
Exchange Membrane ◽  
Turbomachinery Design

To cover the increasing demand of on-board electrical power and for further reduction of emissions, the conventional auxiliary power unit (APU) may be replaced by a fuel cell system with an expected efficiency increase of 25% to 50% when compared to start-of-the-art GT-APU. The main components of an in-flight FC system are a compressor-turbine unit, a kerosene reformer, and the fuel cell. Polymer exchange membrane fuel cells (PEM-FC) may be favored because of their currently advanced level of development, their high power density and the available liquid water in the cathode-off gases which can be used as service water on-board. Transient requirements may have significant impact on system design and operating range and will therefore be addressed in this paper. During in-flight operation, air has to be compressed from the ambient to a pressure near standard conditions, which allows the application of state-of-the-art PEM-FC and ensures a constant power density independent from the operating altitude. A centrifugal compressor is chosen for pressurization of the system and is powered by a radial turbine, which allows autonomous operation at cruising altitude without external power. For off-design operation and transients, electric support from the PEM-FC is necessary, see [1]. The radial turbine itself is run by the hot exhaust gases from a post-combustor using the remaining energy in the cathode off-gases. A thorough trade-off between suitable compressor techniques for the air supply system was carried out in [1]. Turbomachinery revealed to be favourable for the PEM air supply system due to their low specific weight and high efficiency. The air supply system resembles the turbocharger for a combustion engine (Fig. 1), which represents a good starting point for a successful integration into the flight environment and further development due to known technology. Based on a turbomachinery design which satisfies the system requirements, the dynamic behavior of the air supply system is analyzed when coupled to the PEM fuel cell. The main focus is on the detection of sensitive system parameters causing system response delay or critical operating conditions. The present paper suggests system features, turbomachinery design parameters and controller types which achieve inherent stability and fast response of the air supply system throughout the entire flight envelope.

Optimization of the Operating Parameters of a Proton Exchange Membrane Fuel Cell for Maximum Power Density

2005 ◽  
Vol 2 (2) ◽  
pp. 121-135 ◽  
Author(s):  
A. Mawardi ◽  
F. Yang ◽  
R. Pitchumani
Keyword(s):  
Fuel Cells ◽  
Fuel Cell ◽  
Power Density ◽  
Proton Exchange Membrane ◽  
Proton Exchange ◽  
Operating Conditions ◽  
Optimum Operating ◽  
Design Parameters ◽  
Membrane Thickness ◽  
Exchange Membrane

The performance of fuel cells can be significantly improved by using optimum operating conditions that maximize the power density subject to constraints. Despite its significance, relatively scant work is reported in the open literature on the model-assisted optimization of fuel cells. In this paper, a methodology for model-based optimization is presented by considering a one-dimensional nonisothermal description of a fuel cell operating on reformate feed. The numerical model is coupled with a continuous search simulated annealing optimization scheme to determine the optimum solutions for selected process constraints. Optimization results are presented over a range of fuel cell design parameters to assess the effects of membrane thickness, electrode thickness, constraint values, and CO concentration on the optimum operating conditions.

scholarly journals Tailored Centrifugal Turbomachinery for Electric Fuel Cell Turbocharger

2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Dietmar Filsinger ◽  
Gen Kuwata ◽  
Nobuyuki Ikeya
Keyword(s):  
Fuel Cells ◽  
Fuel Cell ◽  
Power Density ◽  
Cell System ◽  
Operating Conditions ◽  
Hydrogen Fuel Cell ◽  
Charging System ◽  
Air Supply ◽  
Exhaust Energy ◽  
Compressor Power

Hydrogen fuel cell technology is identified as one option for allowing efficient vehicular propulsion with the least environmental impact on the path to a carbon-free society. Since more than 20 years, IHI is providing charging systems for stationary fuel cell applications and since 2004 for mobile fuel cell applications. The power density of fuel cells substantially increases if the system is pressurized. However, contaminants from fuel cell system components like structural materials, lubricants, adhesives, sealants, and hoses have been shown to affect the performance and durability of fuel cells. Therefore, the charging system that increases the pressure and the power density of the stacks inevitably needs to be oil-free. For this reason, gas bearings are applied to support the rotor of a fuel cell turbocharger. It furthermore comprises a turbine, a compressor, and, on the same shaft, an electric motor. The turbine utilizes the exhaust energy of the stack to support the compressor and hence lower the required electric power of the air supply system. The presented paper provides an overview of the fuel cell turbocharger technology. Detailed performance investigations show that a single-stage compressor with turbine is more efficient compared to a two-stage compressor system with intercooler. The turbine can provide more than 30% of the required compressor power. Hence, it substantially increases the system efficiency. It is also shown that a fixed geometry turbine design is appropriate for most applications. The compressor is of a low specific speed type with a vaneless diffuser. It is optimized for operating conditions of fuel cell systems, which typically require pressure ratios in the range of 3.0.

scholarly journals Measurements Based Analysis of the Proton Exchange Membrane Fuel Cell Operation in Transient State and Power of Own Needs

Energies ◽  
2020 ◽  
Vol 13 (2) ◽  
pp. 498
Author(s):  
Andrzej Wilk ◽  
Daniel Węcel
Keyword(s):  
Fuel Cells ◽  
Fuel Cell ◽  
Proton Exchange Membrane ◽  
Transient State ◽  
Experimental Tests ◽  
Cell System ◽  
Proton Exchange ◽  
Operating Conditions ◽  
Variable Load ◽  
Exchange Membrane

Currently, fuel cells are increasingly used in industrial installations, means of transport, and household applications as a source of electricity and heat. The paper presents the results of experimental tests of a Proton Exchange Membrane Fuel Cell (PEMFC) at variable load, which characterizes the cell’s operation in real installations. A detailed analysis of the power needed for operation fuel cell auxiliary devices (own needs power) was carried out. An analysis of net and gross efficiency was carried out in various operating conditions of the device. The measurements made show changes in the performance of the fuel cell during step changing or smooth changing of an electric load. Load was carried out as a change in the current or a change in the resistance of the receiver. The analysis covered the times of reaching steady states and the efficiency of the fuel cell system taking into account auxiliary devices. In the final part of the article, an analysis was made of the influence of the fuel cell duration of use on obtained parameters. The analysis of the measurement results will allow determination of the possibility of using fuel cells in installations with a rapidly changing load profile and indicate possible solutions to improve the performance of the installation.

Controlling fuel crossover and hydration in ultra-thin proton exchange membrane-based fuel cells using Pt-nanosheet catalysts

2014 ◽  
Vol 2 (39) ◽  
pp. 16416-16423 ◽  
Author(s):  
Rujie Wang ◽  
Wenjing Zhang ◽  
Gaohong He ◽  
Ping Gao
Keyword(s):  
Fuel Cells ◽  
Fuel Cell ◽  
Power Density ◽  
Proton Exchange Membrane ◽  
Proton Exchange ◽  
Exchange Membrane

A fuel cell with a 9 μm thick proton exchange membrane bearing Pt-nanosheet catalysts delivered 200% more power density as compared with a fuel cell with commercial Nafion® 211 membrane.

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.

Thermodynamic Analysis of the Performance of an Irreversible PEMFC

2018 ◽  
Vol 388 ◽  
pp. 350-360 ◽  
Author(s):  
Chang Jie Li ◽  
Ye Liu ◽  
Zhe Shu Ma
Keyword(s):  
Fuel Cells ◽  
Fuel Cell ◽  
Proton Exchange Membrane ◽  
Pem Fuel Cells ◽  
Proton Exchange ◽  
Operating Conditions ◽  
Operating Pressure ◽  
Controllable Factors ◽  
Temperature Operating ◽  
Exchange Membrane

An irreversible model of proton exchange membrane fuel cells working at steady-state is established, in which the irreversibility resulting from overpotentials, internal currents and leakage currents are taken into account．In this paper, the irreversibility of fuel cell is expounded mainly from electrochemistry. The general performance characteristic curves are generated including output voltage, output power and output efficiency. In addition, the irreversibility of a class of PEMFC is studied by changing the operating conditions (controllable factors) of the fuel cell, including effect of operating temperature, operating pressure and leakage current. The results provide a theoretical basis for both the operation and optimal design of real PEM fuel cells．

Numerical Analysis of Water Transport in PEM Fuel Cell Membranes Using a Phenomenological Model

2004 ◽  
Author(s):  
P. C. Sui ◽  
N. Djilali
Keyword(s):  
Fuel Cell ◽  
Water Content ◽  
Water Transport ◽  
Phenomenological Model ◽  
Proton Exchange Membrane ◽  
Proton Exchange ◽  
Operating Conditions ◽  
Design Parameters ◽  
Exchange Membrane ◽  
And Diffusion

A numerical investigation on the water transport across the membrane of a proton exchange membrane fuel cell is carried out to gain insight into water management issues, which are crucial to the efficient operation of such fuel cells. The transport equation of water content based on a phenomenological model, which includes an electro-osmotic drag term and a diffusion term, is solved using the finite volume method for a 1-D configuration with the assumption of a uniform temperature distribution. Transport properties including the drag coefficient and diffusion coefficient of water in the membrane and the ionic conductivity of the membrane are expressed as functions of water content and temperature. The effects on the water flux across the membrane and on overall membrane protonic conductivity due to variations of these properties are studied. The numerical results show that water transport in the membrane is mainly determined by the relative strength of electro-osmotic drag and diffusion, which are affected by operating conditions such as current density and relative humidity at the membrane surface, and design parameters such as membrane thickness and membrane material. Computed water fluxes for different humidity boundary conditions indicate that for a thick membrane, e.g. Nafion 117, electro-osmotic drag dominates transport over a wide range of operating conditions, whereas for a thin membrane, e.g. Nafion 112, diffusion of water becomes equally important under certain conditions. Implications of the one-dimensional investigation on comprehensive CFD based modelling of proton exchange membrane fuel cell are also discussed.

scholarly journals Optimal Estimation of Proton Exchange Membrane Fuel Cells Parameter Based on Coyote Optimization Algorithm

2021 ◽  
Vol 11 (5) ◽  
pp. 2052
Author(s):  
Amlak Abaza ◽  
Ragab A. El-Sehiemy ◽  
Karar Mahmoud ◽  
Matti Lehtonen ◽  
Mohamed M. F. Darwish
Keyword(s):  
Fuel Cells ◽  
Fuel Cell ◽  
Optimization Algorithm ◽  
Distribution Systems ◽  
Proton Exchange Membrane ◽  
Pem Fuel Cell ◽  
Pem Fuel Cells ◽  
Proton Exchange ◽  
Operating Conditions ◽  
Exchange Membrane

In recent years, the penetration of fuel cells in distribution systems is significantly increased worldwide. The fuel cell is considered an electrochemical energy conversion component. It has the ability to convert chemical to electrical energies as well as heat. The proton exchange membrane (PEM) fuel cell uses hydrogen and oxygen as fuel. It is a low-temperature type that uses a noble metal catalyst, such as platinum, at reaction sites. The optimal modeling of PEM fuel cells improves the cell performance in different applications of the smart microgrid. Extracting the optimal parameters of the model can be achieved using an efficient optimization technique. In this line, this paper proposes a novel swarm-based algorithm called coyote optimization algorithm (COA) for finding the optimal parameter of PEM fuel cell as well as PEM stack. The sum of square deviation between measured voltages and the optimal estimated voltages obtained from the COA algorithm is minimized. Two practical PEM fuel cells including 250 W stack and Ned Stack PS6 are modeled to validate the capability of the proposed algorithm under different operating conditions. The effectiveness of the proposed COA is demonstrated through the comparison with four optimizers considering the same conditions. The final estimated results and statistical analysis show a significant accuracy of the proposed method. These results emphasize the ability of COA to estimate the parameters of the PEM fuel cell model more precisely.

Potential Applications of Fuel Cells for Hybrid Electric Aircrafts: Case Study

2019 ◽  
Author(s):  
Sreedhar Kari ◽  
George Thorne ◽  
John Szeki ◽  
Chris Hall ◽  
Lindsey Mortimer ◽  
...  
Keyword(s):  
Fuel Cells ◽  
Fuel Cell ◽  
Case Studies ◽  
Power Density ◽  
Proton Exchange Membrane ◽  
Pem Fuel Cells ◽  
Proton Exchange ◽  
Potential Applications ◽  
Aero Engines ◽  
Exchange Membrane

Abstract Increased greenhouse gas emissions have an adverse impact on climate change. Recently, there is an increased drive to reduce the emissions especially after the Paris agreement 2015. There are several research initiatives that have been started in the aerospace industry to reduce the emissions like NOx, CO2 and other harmful substances. This paper presents the case studies done on the potential applications of fuel cells for more electric aircrafts (MEA) to achieve the reduced emissions and reduced fuel consumption. The objective of this paper is to take a broad view of how fuel cell technology works, various types of existing technologies and their potential applications and challenges for aero engines in terms of power density. In this study, the different types of fuel cells e.g. low temperature Proton Exchange Membrane (PEM) fuel cells and high temperature solid oxide fuel cells (SOFC) etc were studied and identified the opportunities and challenges to make them work for aero engines as a part of electrification. Different ways of storing the hydrogen on board have been explored. The comparison has been made with battery vs fuel cell power density including the H2 tank. The case studies were made for potential replacement of shaft power off take on civil large engines with fuel cells for hybrid long range aircrafts and regional propeller jets with fully electric power.

A low-loading Ru-rich anode catalyst for high-power anion exchange membrane fuel cells

2020 ◽  
Vol 56 (42) ◽  
pp. 5669-5672
Author(s):  
Zhanna Tatus-Portnoy ◽  
Anna Kitayev ◽  
Thazhe Veettil Vineesh ◽  
Ervin Tal-Gutelmacher ◽  
Miles Page ◽  
...  
Keyword(s):  
Fuel Cells ◽  
Fuel Cell ◽  
Anion Exchange ◽  
Power Density ◽  
High Power ◽  
Peak Power ◽  
Anion Exchange Membrane ◽  
Anode Catalyst ◽  
Peak Power Density ◽  
Exchange Membrane

Herein, we report a Ru-rich anode catalyst for alkaline exchange membrane fuel cells. At 80 °C, a fuel cell with a RuPdIr/C anode and Ag based cathode attained a peak power density close to 1 W cm−2 with 0.2 mg cm−2 anode loading in comparison to 0.77 W cm−2 for the cell tested with the same metal loading of Pt.

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