Autore	Firat Ahmet Evren
Edizione	[1. Auflage.]
Pubbl/distr/stampa	Gottingen, [Germany] : , : Cuvillier Verlag, , 2016
Descrizione fisica	1 online resource (118 pages) : illustrations (some color), photographs, tables, graphs
Disciplina	621.312429
Soggetto topico	Proton exchange membrane fuel cells Proton exchange membrane fuel cells - Design and construction
Soggetto genere / forma	Electronic books.
ISBN	3-7369-8257-7
Formato	Materiale a stampa
Livello bibliografico	Monografia
Lingua di pubblicazione	eng
Record Nr.	UNINA-9910511684703321

Autore	Scholz Hannes
Pubbl/distr/stampa	Berlin : , : Logos Verlag, , 2015
Descrizione fisica	1 online resource (205 pages)
Disciplina	621.312429
Collana	AutoUni-Schriftenreihe
Soggetto topico	Proton exchange membrane fuel cells
Soggetto genere / forma	Electronic books.
ISBN	3-8325-9450-7
Formato	Materiale a stampa
Livello bibliografico	Monografia
Lingua di pubblicazione	ger
Record Nr.	UNINA-9910468049403321

Autore	Wang Yun
Pubbl/distr/stampa	New York : , : Momentum Press, LLC, , [2013]
Descrizione fisica	1 online resource (420 p.)
Disciplina	621.312429
Soggetto topico	Proton exchange membrane fuel cells
Soggetto genere / forma	Electronic books.
ISBN	1-299-45668-5 1-60650-247-6
Formato	Materiale a stampa
Livello bibliografico	Monografia
Lingua di pubblicazione	eng
Nota di contenuto	Preface -- List of figures -- List of tables -- Nomenclature -- 1. Introduction -- 1.1 Energy challenges -- 1.2 Fuel cells and their roles in addressing the energy challenges -- 1.3 PEM fuel cells -- 1.3.1 PEM fuel cell operation -- 1.3.2 Current status of PEM fuel cells -- 1.3.3 Thermal and water management -- 2. Basics of PEM fuel cells -- 2.1 Thermodynamics -- 2.1.1 Internal energy and the first law of thermodynamics -- 2.1.2 Enthalpy change -- 2.1.3 Entropy change and the second law of thermodynamics -- 2.1.4 Gibbs free energy and thermodynamic voltage -- 2.1.5 Chemical potential and Nernst equation -- 2.1.6 Relative humidity and phase change -- 2.2 Electrochemical reaction kinetics -- 2.2.1 Electrochemical kinetics -- 2.2.2 Electrochemical mechanisms in PEM fuel cells -- 2.2.3 Linear approximation and Tafel equation -- 2.3 Voltage loss mechanisms and a simplified model -- 2.3.1 Open circuit voltage (OCV) -- 2.3.2 Activation loss -- 2.3.3 Ohmic loss -- 2.3.4 Transport voltage loss -- 2.3.5 Current-voltage (I-V) curve and operation efficiency -- 2.3.6 Role of water and thermal management -- 2.4 Chapter summary -- 3. Fundamentals of heat and mass transfer -- 3.1 Introduction -- 3.2 Conservation equations -- 3.2.1 General forms -- 3.2.2 Mass and momentum conservation -- 3.2.3 Energy equation -- 3.2.4 Species transport equation -- 3.3 Constitutive equations -- 3.3.1 A lattice model -- 3.3.2 Fourier's law and Fick's law -- 3.4 Scaling and dimensionless groups -- 3.4.1 Scaling and dimensionless equations -- 3.4.2 Dimensionless groups -- 3.5 Chapter summary -- 4. Water and its transport in the polymer electrolyte membrane -- 4.1 Introduction to the polymer electrolyte membrane -- 4.2 Ion transport and ionic conductivity -- 4.2.1 Proton transport -- 4.2.2 Ionic conductivity correlations -- 4.2.3 Ionic conductivity measurement -- 4.3 Water transport in polymer electrolyte membranes -- 4.3.1 Transport mechanisms -- 4.3.2 Water holding capacity -- 4.4 Water quantification using neutron radiography -- 4.5 Ion transport in cathode catalyst layers -- 4.5.1 Variation in water content in catalyst layers -- 4.5.2 Proton transport in cathode catalyst layers -- 4.5.3 Multiple-layered cathode catalyst layers -- 4.6 Chapter summary -- 5. Vapor-phase water removal and management -- 5.1 Mass transport overview -- 5.2 Diffusion -- 5.2.1 Diffusivity -- 5.2.2 Molecular versus Knudsen diffusion -- 5.2.3 Diffusion in GDLs -- 5.3 Species convection -- 5.3.1 Flow modeling with constant-flow assumption -- 5.3.2 Flow formulation without the constant-flow assumption -- 5.3.3 Convection in GDLs -- 5.4 Pore-scale transport -- 5.4.1 Stochastic material reconstruction -- 5.4.2 Pore-scale transport modeling -- 5.4.3 Pore-level phenomena -- 5.5 Transient phenomena -- 5.5.1 Transient terms and time constants -- 5.5.2 Transient undergoing constant voltage or step change in voltage -- 5.5.3 Transient undergoing constant current or step change in current -- 5.6 Water management between a PEM fuel cell and fuel processor -- 5.6.1 Water balance model -- 5.6.2 Effect of the steam-to-carbon ratio -- 5.7 Chapter summary -- 6. Liquid water dynamics and removal -- 6.1 Multiphase flow overview -- 6.1.1 Modeling multi-phase flows -- 6.2 Multiphase flow in GDLS/CLS -- 6.2.1 Experimental visualization -- 6.2.1.1 X-ray imaging -- 6.2.1.2 Neutron radiography -- 6.2.2 Multiphase mixture (M2) formulation -- 6.2.2.1 Flow equations -- 6.2.2.2 Species transport -- 6.2.2.3 Model prediction -- 6.2.3 Carbon paper (CP) versus carbon cloth (CC) -- 6.2.4 Spatially varying properties -- 6.2.4.1 Through-plane variation in the GDL property -- 6.2.4.2 In-plane property variation and the effect of land compression -- 6.2.4.3 Microporous layers (MPLs) -- 6.3 Multiphase flow in gas flow channels (GFCS) -- 6.3.1 Experimental visualization -- 6.3.2 Two-phase flow patterns -- 6.3.3 Modeling two-phase flow -- 6.3.3.1 The mixture model -- 6.3.3.2 Two-fluid modeling -- 6.4 Water droplet dynamics at the GDL/GFC interface -- 6.4.1 Force balance on a spherical-shape droplet -- 6.4.2 Droplet deformation -- 6.4.3 Droplet detachment -- 6.4.3.1 Control volume method -- 6.4.3.2 Derivation using the drag coefficient (CD) -- 6.5 Chapter summary -- 7. Ice dynamics and removal -- 7.1 Subfreezing operation-overview -- 7.2 Ice formation -- 7.2.1 Water transport and conservation -- 7.2.2 Three cold-start stages -- 7.2.2.1 First stage: membrane hydration -- 7.2.2.2 Second stage: ice formation -- 7.2.2.3 Third stage: ice melting -- 7.3 Voltage loss due to ice formation -- 7.3.1 Spatial variation of the oxygen reduction reaction (ORR) -- 7.3.2 The ORR rate under subfreezing temperature -- 7.3.3 Oxygen profile in the catalyst layer -- 7.3.4 Voltage loss due to ice formation -- 7.3.5 A model of cold-start cell voltage -- 7.4 State of subfreezing water -- 7.5 Chapter summary -- 8. Thermal transport and management -- 8.1 Heat transfer overview -- 8.1.1 Heat transfer and its importance -- 8.1.2 Heat transfer modes -- 8.1.2.1 Heat conduction -- 8.1.2.2 Convective heat transfer -- 8.1.2.3 Heat radiation -- 8.1.3 Heat transfer in porous media -- 8.2 Heating mechanisms -- 8.2.1 The entropic heat -- 8.2.2 Irreversibility of the electrochemical reactions -- 8.2.3 The Joules heat -- 8.3 Steady-state heat transfer -- 8.3.1 One-dimensional (1D) heat transfer analysis -- 8.3.2 Two-dimensional (2D) heat transfer analysis -- 8.3.3 Numerical analysis -- 8.3.3.1 Macroscopic model prediction -- 8.3.3.2 Pore-level heat transfer -- 8.4 Transient phenomena -- 8.4.1 General transient operation -- 8.4.2 Transient subfreezing operation -- 8.4.2.1 Temperature evolution and voltage loss -- 8.4.2.2 Activation voltage loss -- 8.4.2.3 Ohmic voltage loss -- 8.5 Experimental measurement of thermal conductivity -- 8.6 Cooling methods -- 8.6.1 Heat spreaders cooling -- 8.6.2 Cooling by air or liquid flow -- 8.6.3 Phase-change-based cooling -- 8.7 Example: a thermal system of automotive fuel cells -- 8.7.1 A lumped-system model of a PEM fuel cell -- 8.7.2 Bypass valve -- 8.7.3 Radiator -- 8.7.4 Transport delay -- 8.7.5 Fluid mixer -- 8.7.6 Cathode intercooler -- 8.7.7 Anode heat exchanger -- 8.8 Chapter summary -- 9. Coupled thermal-water management: phase change -- 9.1 Introduction to phase change -- 9.2 Vapor-liquid phase change: evaporation and condensation -- 9.2.1 Vapor-phase water diffusion and heat pipe effect -- 9.2.2 GDL de-wetting -- 9.2.3 GDL de-wetting and voltage loss -- 9.2.4 A general definition of the Damkohler number, Da -- 9.2.4.1 Local heating and vapor-phase removal -- 9.2.4.2 A specific Damkohler number -- 9.2.4.3 Liquid-free passages -- 9.2.4.4 2D numerical simulation -- 9.3 Freezing/thawing -- 9.3.1 Temperature spatial and temporal variation -- 9.3.2 Non-isothermal cold start -- 9.3.3 Freezing/thawing and degradation -- 9.4 System-level analysis of coupled thermal and water management -- 9.4.1 Flow rates of species and two-phase flows -- 9.4.2 Energy balance -- 9.5 Chapter summary.
Record Nr.	UNINA-9910452283403321

Pubbl/distr/stampa	New York, : Nova Science Publishers, c2009
Descrizione fisica	1 online resource (475 p.)
Disciplina	621.31/2429
Altri autori (Persone)	EspositoRichard <1963-> ContiAntonio <1962->
Soggetto topico	Proton exchange membrane fuel cells Electrocatalysis
Soggetto genere / forma	Electronic books.
ISBN	1-61728-563-3
Formato	Materiale a stampa
Livello bibliografico	Monografia
Lingua di pubblicazione	eng
Nota di contenuto	""POLYMER ELECTROLYTE MEMBRANEFUEL CELLS AND ELECTROCATALYSTS""; ""CONTENTS""; ""PREFACE""; ""SYNTHESIS OF POLYMER ELECTROLYTE MEMBRANEFOR FUEL CELL APPLICATIONS ""; ""ABSTRACT""; ""1. INTRODUCTION""; ""2. MATERIALS AND METHODS""; ""2.1 Materials""; ""2.2 Membrane Manufacturing Procedures""; ""3. EVALUATION OF PROTON EXCHANGE MEMBRANE(PEM) PERFORMANCE""; ""3.1 Conductivity""; ""3.1.1 Through-Plane Conductivity Measurements""; ""Advantages""; ""Disadvantages""; ""3.1.2 In-Plane Conductivity Measurements""; ""Advantages""; ""Disadvantages""; ""3.2 Resistance"" ""3.3 Theoretical Model to Measure Membrane Conductivity and ResistanceBased on Proton Flow""""3.4 Experimental Set-Up and Procedures""; ""3.4.1 Measurement of Proton Transfer Rate and Membrane Resistance""; ""3.4.2 pH Measuring Process and Calculation of Proton Concentration""; ""3.4.3 Measurement of Proton Transfer""; ""4. RESULTS AND DISCUSSIONS""; ""4.1 Thermal Stability of Membrane Conductivity""; ""4.2 Relative Resistance""; ""4.3 Water Uptake Content""; ""5. CONCLUSIONS""; ""REFERENCES""; ""THE DEVELOPMENT OF BIPOLAR PLATE MATERIALSFOR POLYMER ELECTROLYTE MEMBRANE FUELCELLS (PEMFC)"" ""ABSTRACT""""Keywords:""; ""1. FUEL CELLS""; ""2. POLYMER ELECTROLYTE MEMBRANE FUEL CELLS (PEMFCS)""; ""2.1 What is PEMFCs?""; ""2.2 Why Are PEMFCs so Important?""; ""2.3 How do PEMFCs Work?""; ""2.3.1 Activation Polarization""; ""2.3.2 Ohmic Polarization""; ""2.3.3 Concentration Polarization""; ""2.3.4 Reactant Crossover and Internal Current Losses""; ""3. BIPOLAR PLATES AND THEIR DESIGN""; ""3.1 What Are the Bipolar Plates?""; ""3.2 Why Are the Bipolar Plates Important?""; ""3.3 Bipolar Plate Design""; ""Pin-Type Flow Field""; ""Straight Flow Field""; ""Serpentine Flow Field"" ""Integrated Flow Field""""Interdigitated Flow Field""; ""Flow-Field Designs Made From Metal Sheets""; ""3.4 Materials for Bipolar Plates""; ""3.4.1 Graphite Bipolar Plates""; ""3.4.2 Composite Bipolar Plates""; ""3.4.3 Metallic Bipolar Plates""; ""3.4.3.1 Uncoated Metals""; ""3.4.3.2 Coated Metals""; ""4. CONCLUDING REMARKS""; ""REFERENCE""; ""FUEL CELL CONVERTERSFOR HIGH POWER APPLICATIONS""; ""ABSTRACT""; ""I. INTRODUCTION""; ""II. FUEL CELL TECHNOLOGY""; ""A. Basic Principle""; ""B. Proton Exchange Membrane Fuel Cell""; ""C. PEM Fuel Cell System""; ""D. PEM Fuel Cell Performance"" ""1. Static Characteristics""""2. Dynamic Characteristics""; ""III. FUEL CELL POWER CONDITIONING""; ""IV. FUEL CELL POWER CONVERTERS""; ""A. Non-Isolated Converter""; ""1. Design Example of 2-Phase Interleaved Fuel Cell Converter [114]""; ""2. Experimental Results of 2-Phase Interleaved Fuel Cell Converter""; ""B. Modified Non-Isolated Converter""; ""C. Ground Isolated Converter""; ""V. CONCLUSION""; ""ACKNOWLEDGMENT""; ""BIOGRAPHIES""; ""Phatiphat Thounthong""; ""Bernard Davat""; ""REFERENCES""; ""CFD MODELS FOR ANALYSIS AND DESIGNOF AMBIENT AIR-BREATHING PEM FUEL CELLS""; ""ABSTRACT"" ""1. INTRODUCTION""
Record Nr.	UNINA-9910459774503321