Hybrid Systems Based on Solid Oxide Fuel Cells

A comprehensive guide to the modelling and design of solid oxide fuel cell hybrid power plants

This book explores all technical aspects of solid oxide fuel cell (SOFC) hybrid systems and proposes solutions to a range of technical problems that can arise from component integration. Following a general introduction to the state-of-the-art in SOFC hybrid systems, the authors focus on fuel cell technology, including the components required to operate with standard fuels. Micro-gas turbine (mGT) technology for hybrid systems is discussed, with special attention given to issues related to the coupling of SOFCs with mGTs. Throughout the book emphasis is placed on dynamic issues, including control systems used to avoid risk conditions.

With an eye to mitigating the high costs and risks incurred with the building and use of prototype hybrid systems, the authors demonstrate a proven, economically feasible approach to obtaining important experimental results using simplified plants that simulate both generic and detailed system-level behaviour using emulators. Computational models and experimental plants are developed to support the analysis of SOFC hybrid systems, including models appropriate for design, development and performance analysis at both component and system levels.

• Presents models for a range of size units, technology variations, unit coupling dynamics and start-up and shutdown behaviours

• Focuses on SOFCs integration with mGTs in light of key constraints and risk avoidance issues under steady-state conditions and during transient operations

• Identifies interaction and coupling problems within the GT/SOFC environment, including exergy analysis and optimization

• Demonstrates an economical approach to obtaining important experimental results while avoiding high-cost components and risk conditions

• Presents analytical/computational and experimental tools for the efficient design and development of hardware and software systems

Hybrid Systems Based on Solid Oxide Fuel Cells: Modelling and Design is a valuable resource for researchers and practicing engineers involved in fuel cell fundamentals, design and development. It is also an excellent reference for academic researchers and advanced-level students exploring fuel cell technology.

Auteur

MARIO L. FERRARI is Associate Professor in the Dipartimento di Ingeneria Meccanica, Energetica,
Gestionale ed dei Trasporti (DIME) of the University of Genova, Italy.

USMAN M. DAMO is at the School of Mechanical, Aerospace and Civil Engineering, The University of Manchester, UK, as a Research Associate.

ALI TURAN is a Professor and chair holder in the thermodynamics of power generation and propulsion
at the University of Manchester, UK.

DAVID SÁNCHEZ is currently a Professor in Energy Systems and Turbomachinery in the Department of Energy Engineering at the University of Seville, Spain.

Contenu

Preface xi

Acknowledgements xv

1 Introduction 1

1.1 World Population Growth, Energy Demand and its Future 1

1.2 World Energy Future 3

1.3 Introduction to Fuel Cells and Associated Terms 6

1.3.1 Background for Fuel Cells and Thermodynamic Principles 6

1.3.2 Solid Oxide Fuel Cells (SOFCs) 11

1.3.3 Fuel Cell Reactions 15

1.3.4 Fuel Cell Performance 15

1.3.5 Pressure and Concentration Effects 18

1.3.6 Irreversibilities in Fuel Cells 19

1.3.7 Fuel Cell Applications 23

1.4 Gas Turbines 24

1.4.1 Background of Gas Turbines 24

1.5 Coupling of Microturbines with Fuel Cells to Obtain 'Hybrid Systems' 25

1.5.1 Active Hybrid Systems Research Groups 29

1.6 Conclusions 29

References 29

2 SOFC Technology 33

2.1 Basic Aspects of Solid Oxide Fuel Cells 33

2.2 SOFC Types 35

2.2.1 High-temperature SOFCs 35

2.2.2 Intermediate/Low-temperature SOFCs 35

2.3 Materials for SOFCs 36

2.4 Different SOFC Geometries 38

2.4.1 Tubular SOFCs 39

2.4.2 Planar SOFCs 41

2.5 SOFC Stacks 43

2.6 Effect of Pressurization for SOFCs 44

2.7 Fuel Processing for SOFCs 45

2.7.1 Processing for Gas and Liquid Fuels 46

2.7.2 Processing for Solid Fuels 48

2.8 SOFC Applications in Hybrid Systems 49

2.8.1 Atmospheric SOFC Hybrid Systems 50

2.8.2 Pressurized SOFC Hybrid Systems 51

2.9 Aspects Related to SOFC Reliability, Degradation and Costs 52

2.10 Conclusions 54

2.11 Questions 54

References 55

3 Micro Gas Turbine Technology 59

3.1 Fundamentals of the Brayton Cycle 59

3.1.1 The Simple Cycle 59

3.1.2 The Simple Recuperative Cycle 68

3.1.3 The Intercooled and Reheat Brayton Cycles 74

3.1.4 The Intercooled and Reheat, Recuperative Brayton Cycle 79

3.1.5 Cycle Layouts used by Contemporary Micro Gas Turbines 84

3.2 Turbomachinery 85

3.2.1 General Considerations on the Selection of Turbomachinery for Micro Gas Turbines 85

3.2.2 Fundamentals of Radial Compressor Design and Performance 89

3.2.3 Some Notes on Compressor Surge 101

3.2.4 Fundamentals of Radial Turbine Design and Performance 105

3.2.5 Scaling of Radial Turbomachinery 113

3.3 Recuperative Heat Exchanger 115

3.4 Bearings 124

3.5 Conclusions: Commercial Status and Areas of Research 131

3.6 Questions and Exercises 134

References 135

4 SOFC/mGT Coupling 141

4.1 Basic Aspects of SOFC Hybridization 141

4.2 SOFC Coupling with Traditional Power Plants 143

4.2.1 Coupling with Steam Power Plants 143

4.2.2 Coupling with Gas Turbines 144

4.2.3 Coupling with Combined Cycle-based Plants 146

4.3 Beneficial Attributes Related to SOFC/mGT Coupling 147

4.4 Constraints Related to SOFC/mGT Coupling 150

4.4.1 Turbine System Constraints 152

4.4.2 SOFC System Constraints 156

4.4.3 Control System Constraints 158

4.5 Design and Off-design Aspects 159

4.5.1 Design Aspects 159

4.5.2 Off-design Aspects 161

4.6 Issues Related to Dynamic Aspects 163

4.7 Main Prototypes Developed for SOFC Hybrid Systems 166

4.7.1 Prototype by Siemens-Westinghouse 167

4.7.2 Prototype by Mitsubishi Heavy Industries 169

4.7.3 Prototype by Rolls-Royce Fuel Cell Systems 170

4.8 Conclusions 171

4.9 Questions and Exercises 173

References 174

5 Computational Models for Hybrid Systems 183

5.1 Introduction 183

5.2 Steady-state Models for Hybrid Systems 185

5.3 Computational Models for Hybrid Systems: Modelling Steps 186 5.3.1 Computational Models for Hybrid Systems at the Component Level 190&...