Download or read book Large Scale Optimization of Proton Exchange Membrane Fuel Cells Using an Adjoint Sensitivity Analysis Approach written by James Meigs Lamb and published by . This book was released on 2021 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: A numerical technique is developed for the design and optimization of the microstructure of proton exchange membrane fuel cells. The technique is based on evaluating the sensitivity functions of the different variables that need to by optimized (such as the two-dimensional or three-dimensional platinum distributions in the catalyst layers and the distributions of the porosity and carbon content in the catalyst and gas diffusion layers) and is using a gradient based technique to compute the optimum of these distributions. The sensitivity functions are computed using a novel adjoint-method approach that is presented in detail in this dissertation and which proves to be robust, reliable, and numerically efficient. This optimization technique is relatively general and can also be applied to the optimization of other variables of the fuel cells, such as geometric dimensions and cell structure. Our numerical results show an increase of 10-15% in the power density of conventional fuel cells as a result of keeping the total amount of platinum constant but properly redistributing it throughout the catalyst layer. We also show that one can increase the power density of conventional PEMFCs by approximately 20% by optimizing the distributions of the Nafion, carbon, and catalyst content in in the cell simultaneously.

Download or read book Computational Modeling and Optimization of Proton Exchange Membrane Fuel Cells written by and published by . This book was released on 2007 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Improvements in performance, reliability and durability as well as reductions in production costs, remain critical prerequisites for the commercialization of proton exchange membrane fuel cells. In this thesis, a computational framework for fuel cell analysis and optimization is presented as an innovative alternative to the time consuming trial-and-error process currently used for fuel cell design. The framework is based on a two-dimensional through-the-channel isothermal, isobaric and single phase membrane electrode assembly (MEA) model. The model input parameters are the manufacturing parameters used to build the MEA: platinum loading, platinum to carbon ratio, electrolyte content and gas diffusion layer porosity. The governing equations of the fuel cell model are solved using Netwon's algorithm and an adaptive finite element method in order to achieve quadratic convergence and a mesh independent solution respectively. The analysis module is used to solve two optimization problems: i) maximize performance; and, ii) maximize performance while minimizing the production cost of the MEA. To solve these problems a gradient-based optimization algorithm is used in conjunction with analytical sensitivities. The presented computational framework is the first attempt in the literature to combine highly efficient analysis and optimization methods to perform optimization in order to tackle large-scale problems. The framework presented is capable of solving a complete MEA optimization problem with state-of-the-art electrode models in approximately 30 minutes. The optimization results show that it is possible to achieve Pt-specific power density for the optimized MEAs of 0.422 $g_{Pt}/kW$. This value is extremely close to the target of 0.4 $g_{Pt}/kW$ for large-scale implementation and demonstrate the potential of using numerical optimization for fuel cell design.

Download or read book Joint General Session Batteries and Energy Storage and Fuel Cells Electrolytes and Energy Conversion written by M. Manivannan and published by The Electrochemical Society. This book was released on 2015-07-29 with total page 304 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Proton Exchange Membrane Fuel Cells written by Alhussein Albarbar and published by Springer. This book was released on 2017-11-17 with total page 172 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book examines the characteristics of Proton Exchange Membrane (PEM) Fuel Cells with a focus on deriving realistic finite element models. The book also explains in detail how to set up measuring systems, data analysis, and PEM Fuel Cells’ static and dynamic characteristics. Covered in detail are design and operation principles such as polarization phenomenon, thermodynamic analysis, and overall voltage; failure modes and mechanisms such as permanent faults, membrane degradation, and water management; and modelling and numerical simulation including semi-empirical, one-dimensional, two-dimensional, and three-dimensional models. It is appropriate for graduate students, researchers, and engineers who work with the design and reliability of hydrogen fuel cells, in particular proton exchange membrane fuel cells.

Download or read book Proton Exchange Membrane Fuel Cells written by Hui Li and published by CRC Press. This book was released on 2010-04-14 with total page 438 pages. Available in PDF, EPUB and Kindle. Book excerpt: Large-scale commercialization of proton exchange membrane fuel cell (PEMFC) technology has been hindered by issues of reliability, durability, and cost, which are all related to the degradation of fuel cell performance. This degradation often has root causes in contamination from fuel, air streams, or system components. With contributions from inte

Download or read book PEM Fuel Cells with Bio Ethanol Processor Systems written by Marta S. Basualdo and published by Springer Science & Business Media. This book was released on 2011-10-30 with total page 479 pages. Available in PDF, EPUB and Kindle. Book excerpt: An apparently appropriate control scheme for PEM fuel cells may actually lead to an inoperable plant when it is connected to other unit operations in a process with recycle streams and energy integration. PEM Fuel Cells with Bio-Ethanol Processor Systems presents a control system design that provides basic regulation of the hydrogen production process with PEM fuel cells. It then goes on to construct a fault diagnosis system to improve plant safety above this control structure. PEM Fuel Cells with Bio-Ethanol Processor Systems is divided into two parts: the first covers fuel cells and the second discusses plants for hydrogen production from bio-ethanol to feed PEM fuel cells. Both parts give detailed analyses of modeling, simulation, advanced control, and fault diagnosis. They give an extensive, in-depth discussion of the problems that can occur in fuel cell systems and propose a way to control these systems through advanced control algorithms. A significant part of the book is also given over to computer-aided engineering software tools that can be used to evaluate the dynamic performance of the overall plant. PEM Fuel Cells with Bio-Ethanol Processor Systems is intended for use by researchers and advanced students on chemical, electrical-electronic and mechanical engineering courses in which dynamics and control are incorporated with the traditional steady-state coverage of flowsheet synthesis, engineering economics and optimization.

Download or read book Modeling and Optimization of PEM Fuel Cells written by Shaoduan Ou and published by . This book was released on 2006 with total page 222 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Boosting Polymer Electrolyte Membrane Fuel Cells from Computational Modeling written by Alejandro A. Franco and published by Academic Press. This book was released on 2018-01-15 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Hydrogen Energy and Fuel Cell Primers is a series of concise books that present those coming into this broad and multidisciplinary field the most recent advances in each of its particular topics. Its volumes bring together information that has thus far been scattered in many different sources under one single title, which makes them a useful reference for industry professionals, researchers and graduate students, especially those starting in a new topic of research. This volume, Boosting Polymer Electrolyte Membrane Fuel Cells from Computational Modeling, explores the use of multiscale computational modeling tools for the design and optimization of PEM fuel cells. Multiscale modeling is a rapidly emerging simulation approach which can potentially boost the R&D on PEMFCs through the development of an understanding of mechanisms and processes occurring at multiple spatio-temporal scales at multiple levels of materials, such as catalyst, catalyst support and ionomer. The book discusses concrete success stories on the application of this approach and their specific outcomes. It reviews the latest progresses in the field, including some contributions from the author himself. Special focus is given to multiscale modeling of degradation mechanisms and the durability prediction of the cells, as well as water transport and membrane degradation. Prior knowledge of electrochemistry and mathematics is assumed. Explores the available tools for multiscale computational modelling applied to the design optimization of PEM fuel cells through Discusses real world applications and the latest progresses in the field Includes modelling of degradation mechanisms and durability prediction

Download or read book Optimization and Characterization of Proton exchange Membrane Fuel Cells Based on Novel Hydrocarbon Ionomers written by Hien Nguyen and published by . This book was released on 2023 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: Hydrogen is a critical energy carrier for defossilising the transportation sector. Proton-exchange membrane (PEM) fuel cells represent a pivotal technology for heavy-duty vehicles, in particular. These fuel cells enable the conversion of hydrogen into electrical energy, with the only by-product being water. State-of-the-art PEM fuel cells rely on perfluorosulfonic acid (PFSA) as cation-exchange material. The synthesis of PFSAs is complex, hazardous and expensive, which limits their production to a few select facilities globally, driving up costs even at high volumes. In recent years, there has been a growing concern over the high level of irreversible environmental damage caused by perfluorinated substances. Leading corporations, such as DuPont and 3M, have faced numerous lawsuits for over a decade. To address these concerns, 3M announced in December 2022 that it would exit the perfluorinated substances business by the end of 2025. An alternative to PFSAs is hydrocarbon ionomers, which offer potentially lower material costs, high thermo-mechanical stability at high operating temperatures, and reduced environmental concerns. While replacing PFSA with hydrocarbon ionomers can make fuel cells more sustainable, it has been observed in earlier studies to compromise performance. The primary objective of this study was to bridge the performance and knowledge gap between hydrocarbon and PFSA-based PEM fuel cells. This was achieved by employing a recently commercialized ionomer called "Pemion". Leveraging this innovative material, this work succeeded in developing a fully hydrocarbon-based fuel cell with outstanding performance, representing a significant breakthrough in 2021. To realize this outcome, the study began with a comprehensive literature review,[1] that identified the most significant limitations associated with hydrocarbon-based fuel cells and proposed strategies for their future commercialization. Systematic know-how transfer was then implemented from the field of PFSA-based materials, encompassing process adaptations and extensive optimization of the catalyst layer to advance towards the state-of-the-art performance of PFSA-based fuel cells. A combination of an ultra-thin monolithic membrane (7 μm) and an optimized ink composition with a platinum-cobalt catalyst enabled a comparable peak performance (> 2 W cm-2) to state-of-the-art PFSA reference cell under optimized laboratory conditions: H2/O2, 80 °C, fully humidified gases and ambient pressure. Electrochemical characterizations under various operating conditions show that the hydrocarbon-based cells' performance is more sensitive to changes in relative humidity than the PFSA reference cell.[2] Based on the proof-of-concept, two follow-up improvement pathways have been identified to improve performance and understanding in hydrocarbon-based fuel cells. First, ionomer gradient catalyst layers have been introduced for hydrocarbon-based fuel cells.[3] A two-fold higher ionomer content compared to the optimized one in 25 % of the catalyst layer at the membrane interface improved the performance by up to 35 % in application-relevant conditions, i.e. reduced humidity, while maintaining high peak performance under the same conditions. Second, different conditioning procedures were investigated on hydrocarbon-based fuel cells for the first time. A novel conditioning procedure developed for hydrocarbon-based fuel cells was found to improve the typically lower performance at low current densities of hydrocarbon-based fuel cells the most efficiently.[4] Based on the findings, fuel cells that use Pemion have been shown to perform similarly to those that use PFSA, but further improvements are required for their application in fuel-cell electric vehicles. To continue improving these fuel cells, it is important to find a balance between effective proton conductivity and mechanical integrity of the ionomer in the catalyst layer for efficient performance under different humidity levels. Reference: [1] Hien Nguyen, Carolin Klose, Lukas Metzler, Severin Vierrath, and Matthias Breitwieser. Fully hydrocarbon membrane electrode assemblies for proton exchange membrane fuel cells and electrolyzers: An engineering perspective. Advanced Energy Materials, 12(12):2103559, 2022. doi:10.1002/aenm.202103559. [2] Hien T. T. Nguyen, Florian Lombeck, Claudia Schwarz, Philipp A. Heizmann, Michael Adamski, Hsu-Feng Lee, Benjamin Britton, Steven Holdcroft, Severin Vierrath, and Matthias Breitwieser. Hydrocarbon-based pemionTM proton exchange membrane fuel cells with state-of-the-art performance. Sustainable Energy & Fuels, (5):3687-3699, 2021. doi:10.1039/D1SE00556A. [3] Hien T. T. Nguyen, Dilara Sultanova, Philipp A. Heizmann, Severin Vierrath, and Matthias Breitwieser. Improving the efficiency of fully hydrocarbon-based proton-exchange membrane fuel cells by ionomer content gradients in cathode catalyst layers. Materials Advances, 2022. doi:10.1039/d2ma00761d. [4] Hien Nguyen, Julian Stiegeler, Hannes Liepold, Claudia Schwarz, Severin Vierrath, and Matthias Breitwieser. A comparative study of conditioning methods for hydrocarbon-based proton-exchange membrane fuel cells for improved performance. doi:https://doi.org/10.1002/ente.202300202

Download or read book Proton Exchange Membrane Fuel Cells for Automotive Applications written by Xuan Liu and published by . This book was released on 2018 with total page 283 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Fuel cells are electrochemical devices that combine hydrogen and oxygen from air to produce electric current, with water and heat as the main co-products. The management of liquid water from either the internal chemical reactions or externally humidified reactants is an important design consideration for proton exchange membrane (PEM) fuel cells because of the effects on both cell performance and durability. To achieve proper water management, significant effort has been devoted to developing new fuel cell materials, hardware designs, and appropriate stack operating conditions. However, water management in the region of the channel-to-manifold interfaces has received limited attention. This region covers the ends of the bipolar plate from where liquid water exits the active area to the entrance of the stack exhaust manifolds where excess reactant flows from individual cells are combined and leave the stack. For practical applications, especially in the anode flow field, there is a small driving force to expel liquid water in this region. Under severe operating conditions such as freezing temperatures, the buildup of water may cause channel-scale blockage. This work investigated the water management of PEM fuel cells in the flow field by both ex-situ experiments and in-situ neutron imaging technique to provide a comprehensive two-phase transport model and propose a water mitigation strategy by flow field surface modification method. The results demonstrate the effects of small variations in cell temperature on water accumulation, which translate into significant changes in cell voltage under some conditions. This water can also influence the pressure drop across both anode and cathode flow fields, and it was found that a small amount of water flow can significantly affect the differential pressure, but further increases in water flux appeared to have an incrementally smaller influence. Additionally, the ex-situ experiments also investigated the water distribution of the inlet non-active area, active area, and outlet non-active area, which confirmed the significance of water management in the channel-to-manifold region. A new empirical correlation was developed to characterize the variation of two-phase friction multiplier (i.e., ratio of two-phase to single-phase [delta]P) with gas and liquid flow rates. In cases where water accumulates in the non-active cell region downstream of the active area, it was determined that hydrophilic bipolar plate coating was effective in reducing or eliminating full-channel water blockages, thus minimizing the start-up time and energy under freezing conditions. The novel research contributions from this part of the dissertation research include: Assessed PEM fuel cell water management behavior in the low non-freezing temperature range (200C to 400C), which significantly affects the reliability and durability of PEM fuel systems, but has received very little attention in the literature. Analyzed water management in the non-active region of the bipolar plate, which not only affects the channel-to-channel water distribution within the fuel cell flow field, but also the cell-to-cell water distribution in a fuel cell stack. This research concluded that water management should focus on the anode side, especially in the outlet channel-to-manifold region. Quantified the water content in a PEM fuel cell flow field using measurements of channel two-phase flow quality and differential pressure. The two-phase transport model developed in this research is capable of quantifying the water volume in PEM fuel cell flow field, and the results showed good agreement with neutron imaging data. Evaluated the water mitigation effectiveness of PEM fuel cell for various surface energy modification locations, and concluded for the first time that only one hydrophilic coated channel in the anode channel-to-manifold transition could substantially facilitate the fuel cell cold start-up process. In addition, there is a significant global activity in assessing and optimizing distributed energy systems in so-called “microgrid” architectures, which in principle enable operation completely independent of the primary electrical grid. A shortcoming of such an approach is that many renewable energy systems are intermittent by nature, and thus supply and demand are often out of phase. This necessitates the implementation of energy storage, but few options exist for cost-effective, large-scale storage. One attractive alternative is to use hydrogen as an energy storage medium, because it offers the possibility for storage at relatively high volumetric density, and hydrogen is readily utilized in various energy applications of immediate interest in large product distribution centers. The dissertation work explored the economic impact of PEM fuel cell material handling equipment (MHE) with comparison to the conventional lead acid battery MHE and the emerging lithium-ion battery MHE. Using data obtained directly from large product distribution centers, it was determined that fuel cells are the low-cost option in installations with large MHE vehicle fleets, multi-shift facilities, and relatively high grid electricity costs. The novel contributions of this analysis stem from it being the first to consider lithium-ion batteries with lead acid batteries and fuel cells as competing MHE propulsion technologies. Moreover, it is the only known study to date to account for the time value of money in the economic analysis, and to consider the target facility fleet configuration using data acquired directly from large product distribution centers in various U.S. locations."--Abstract.

Download or read book High Temperature Proton Exchange Membrane Fuel Cell Optimization of Flow Channel Geometry written by Alexandra Hartz and published by . This book was released on 2013 with total page 196 pages. Available in PDF, EPUB and Kindle. Book excerpt: Several groups are studying and researching major factors which influence high temperature proton exchange membrane fuel cells. These factors include material type, temperature, and fuel cell lifespan. Only a few groups research the optimization of the size of the fuel channels within the fuel cell. For channel optimization, a model was created to find the optimum flow channel and rib widths. The approach used was to code the losses due to activation, concentration, and ohmic polarizations to yield the fuel cell voltage and power expected from the fuel cell itself. The model utilizes the specified cell parameters including the material properties, fuel cell temperature, and channel size. This method gives an initial view of how a fuel cell will perform given specific parameters. It is not limited to one fuel cell size, allowing future research efforts to utilize this model to optimize flow channels in a variety of fuel cells.

Download or read book Water and Thermal Management of Proton Exchange Membrane Fuel Cells written by Kui Jiao and published by Elsevier. This book was released on 2021-06-14 with total page 400 pages. Available in PDF, EPUB and Kindle. Book excerpt: Water and Thermal Management of Proton Exchange Membrane Fuel Cells introduces the main research methods and latest advances in the water and thermal management of PEMFCs. The book introduces the transport mechanism of each component, including modeling methods at different scales, along with practical exercises. Topics include PEMFC fundamentals, working principles and transport mechanisms, characterization tests and diagnostic analysis, the simulation of multiphase transport and electrode kinetics, cell-scale modeling, stack-scale modeling, and system-scale modeling. This volume offers a practical handbook for researchers, students and engineers in the fields of proton exchange membrane fuel cells. Proton exchange membrane fuel cells (PEMFCs) are high-efficiency and low-emission electrochemical energy conversion devices. Inside the PEMFC complex, physical and chemical processes take place, such as electrochemical reaction, multiphase flow and heat transfer. This book explores these topics, and more. Introduces the transport mechanism for each component of PEMFCs Presents modeling methods at different scales, including component, cell, stack and system scales Provides exercises in PEMFC modeling, along with examples of necessary codes Covers the latest advances in PEMFCs in a convenient and structured manner Offers a solution to researchers, students and engineers working on proton exchange membrane fuel cells

Download or read book Optimization and Control Using a Proton Exchange Membrane Fuel Cell Model written by Vinay Prasad and published by . This book was released on 2003 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Design Optimization and Dynamic Studies of Proton Exchange Membrane Fuel Cells PEMFC Using Detailed Models written by R. Madhusudana Rao and published by . This book was released on 2006 with total page 276 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Contribution to Prognostics of Proton Exchange Membrane Fuel Cells written by Dacheng Zhang and published by . This book was released on 2018 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: In the context of the energy transition, fuel cell becomes one of the promising alternative energy sources. Recently the spotlight is on fuel cell systems research, and more particularly on Proton Exchange Membrane Fuel Cell (PEMFCs) which is one of the best candidates for both stationary and transportation applications. Even if this technology is close to being competitive, it is not yet ready to be considered for a large scale industrial deployment because of its limited durability and reliability. Prognostics and Health Management (PHM) is a recent approach to manage and possibly extend life duration of technological systems. Prognostic techniques can provide an estimation of fuel cell State Of Health (SOH) and a prediction for their Remaining Useful Life (RUL) to help the manufacturers improving fuel cell performance and managing its lifespan.The objective of this work is to develop prognostic methodologies for the RUL prognosis adapted to the complexity of PEMFCs. Indeed, the PEMFC is a multi-scale and multi-physics system, and various challenges are faced:1. The definition of SOH to build a degradation indicator.2. The coexistence of both reversible and irreversible degradation phenomena.3. Taking into account different deterioration causes and effects of operating conditions.In the first part of our work, we conduct a state of the art analysis on PHM for PEMFCs, with the aim of proposing a SOH definition and building a degradation indicator for PEMFC prognosis purposes. And since PEMFC measurements are scarce, the state of the art on Lithium batteries, other electrochemical cells, is also explored.In the second part, we develop a particle filtering based prognostic algorithm for PEMFC, based on output power measurements. The first results show that the prognosis algorithm is disturbed by the existing reversible degradation. However, the irreversible degradation can be estimated thanks to characterization tests, such as Electrochemical Impedance Spectroscopy (EIS), which is applied from time to time. We propose thus an adapted & extended prognostic algorithm to take into account both health indicators: the output power degradation and the SOH degradation estimated from EIS characterization. The performance of the proposed algorithm is evaluated by different prognostic performance metrics, and the results show the interest of this approach.In the third part, the problem is addressed from a more theoretical point of view. Indeed, a system's degradation behavior is often correlated with internal and external covariates which are usually difficult to access owing to expensive measurement cost. Therefore, we first developed a prognostic approach with online inspections on the degradation covariate at a different level, and then we propose an approach for RUL prognosis based on an ensemble of models using different sources at different levels. The RUL predictions of both models are dynamically aggregated on the basis of prognostic performance evaluated on a set of historical data. Consequently, the prediction accuracy is improved by overcoming both models' drawbacks and leveraging their strengths. In the last part, we extend the problem to multi-level prognostics and explore new possibilities, which open new aspects for future research on PEMFC lifetime prognosis and management.

Download or read book Long Term Performance Prediction of Proton Exchange Membrane Fuel Cells Using Machine Learning Method written by Yiming Wu and published by . This book was released on 2016 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The environmental issues, especially the global warming due to greenhouse effect, has become more and morecritical in recent decades. As one potential candidate among different alternative "green energy" solutions forsustainable development, the Proton Exchange Membrane Fuel Cell (PEMFC) has been received extensiveresearch attention since many years for energy and transportation applications. The PEMFC stacks, can produceelectricity directly from electrochemical reaction between hydrogen and oxygen in the air, with the only by-productsof water and heat. If the hydrogen is produced from renewable energy sources, this energy conversion is 100% ecofriendly.However, the relatively short lifespan of PEMFCs operating under non-steady-state conditions (for vehicles forexample) impedes its massive use. The accurate prediction of their aging mechanisms can thus help to designproper maintenance patterns of PEMFCs by providing foreseeable performance degradation information. In addition,the prediction could also help to avoid or mitigate the unwanted degradation of PEMFC systems during operation.This thesis proposes a novel data driven approach to predict the performance degradation of the PEMFC using animproved relevance vector machine method.Firstly, the theoretical description of the PEMFC during operation will be presented followed by an extensivelydetailed illustration on impacts of operational conditions on PEMFC performance, along with the degradationmechanisms on each component of PEMFC. Moreover, different approaches of PEMFC performance prediction inthe literature will also be briefly introduced.Further, a performance prediction method using an improved Relevance Vector Machine (RVM) would be proposedand demonstrated. The prediction results based on different training zones from historical data will also bediscussed and compared with the prediction results using conventional Support Vector Machine (SVM).Moreover, a self-adaptive kernel RVM prediction method will be introduced. At the meantime, the design matrix ofthe RVM training will also be modified in order to acquire higher precision during prediction. The prediction resultswill be illustrated and discussed thoroughly in the end.In summary, this dissertation mainly discusses the analysis of the PEMFC performance prediction using advancedmachine learning methods.

Download or read book Study of Proton Exchange Membrane Fuel Cells Pemfc Using Detailed Models for Electrode Structure Optimization written by R. Madhusudana Rao and published by . This book was released on 2005 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: