Hydrogen for Future Thermal Engines

Description

This book explores the potential of hydrogen combustion in thermal engines and serves as a foundation for future research. Hydrogen, a well-established energy carrier, has been used in internal combustion engines for centuries, but despite progress and industry interest, hydrogen engines have yet to reach mass production. In light of recent efforts to combat climate change with clean energy and environmentally-friendly technologies, the use of hydrogen in thermal engines is gaining momentum. This book examines the unique challenges of hydrogen combustion due to its wide flammability limits, high auto-ignition temperature, and high diffusivity. It reviews current knowledge on the fundamental and practical aspects of hydrogen combustion and considers current developments and potential future advancement. Preface Contents About the Editor Fundamental Aspects Hydrogen: Where it Can Be Used, How Much is Needed, What it May Cost 1 From Science to the Rio Earth Summit 2 Hydrogen Programmes Before 2015 3 From Kyoto, Via Paris, to Glasgow and on to 2050 4 Overview: The `Net Zero Emissions Scenario' and the `1.5°C Scenario' 5 Hydrogen: Production and Production Costs 6 Hydrogen: International Distribution and Bulk Storage 7 Ammonia as a Fuel 8 Hydrogen for Land Transport 9 Hydrogen for Ships and Aeroplanes 10 Hydrogen: The Approach in the EU 11 Hydrogen: The Approach in the USA 11.1 Hydrogen: Intended Production Capacity and Demand in the USA 11.2 Hydrogen: Costs, and Programmes for Their Reduction, in the USA 11.3 Hydrogen: Development Over Time in the USA 11.4 Outlook References Reaction Kinetics of Hydrogen Combustion 1 Early History 2 Understanding the Basic Features of the Hydrogen Combustion System Using a 10-Step Mechanism 3 Available Experimental Data 3.1 Indirect Experimental Data 3.2 Direct Measurements and Theoretical Determinations of Rate Coefficients 4 Recent Detailed Reaction Mechanisms 5 New Developments in Hydrogen Combustion Kinetics: Nonthermal Reactions 6 Challenges and Prospects References Hydrogen Laminar Flames 1 Introduction 2 Laminar Premixed Flames Features 2.1 Enhanced Unstretched Laminar Flame Speed SL 2.2 Stretch Effects 2.3 Effecs of Intrinsic Flame Instability 3 Intrinsic Flame Instabilities: Theory 3.1 A Weakly Nonlinear Model for the Flame 3.2 Alternative Approaches for Intrinsic Flame Instabilities 4 Intrinsic Flame Instabilities: Experimental Observations 4.1 Spherical Flames 4.2 Hele-Shaw Cells 5 Intrinsic Flame Instabilities: Simulations 5.1 The Linear Regime 5.2 The Non-linear Regime 5.3 Modeling Aspects References Turbulent Flames of Hydrogen 1 Introduction 2 Turbulent Diffusion Flames 2.1 Global Features 2.2 Compositional Structure 3 Turbulent Premixed Flames 3.1 Global Features 3.2 Flame Speed and Structure 4 Modelling Differential Diffusion 5 Future Prospects 6 Closing Remarks References Hydrogen Ignition and Safety 1 Introduction 2 The Chemistry of H2 Ignition 2.1 Preliminary Definitions and Notation 2.2 Minimal Kinetic Description 2.3 A Simplified Study of High-Temperature Ignition—Crossover Definition 2.4 An Eigenvalue Study of the Branching Reactions 2.5 Radical-Pool Composition 2.6 Analytical Derivation of Branching Times 2.7 Thermal Runaway 2.8 Recap: Analytical Formulas for H2 Induction Times 3 Limit Phenomena in Canonical Flow Configurations 3.1 Explosion in a Closed Vessel: The Three Explosion Limits 3.2 Premixed Flames: Flammability Limits 3.3 Detonation Propagation Limits 3.4 Diffusion Flames: Ignition in Mixing Layer 3.5 Thermal Ignition 3.6 Shock-Induced Ignition 3.7 Diffusion Flames: Extinction Limits 4 How to Ignite: Ignition Strategies 4.1 A Simplified Conceptual Model of a H2 Combustion Chamber 4.2 Ignition Sequence 4.3 Minimal Thermal Power Required 4.4 A List of Igniter Technologies 5 How Not to Ignite: Application to Safety Issues 5.1 A Simple Rule-of-Thumb Example 5.2 A Computational Example: The Cabra H2 Jet Flame 5.3 Post-processing 5.4 A Priori Prediction of Hazardous Ignition from Cold-Flow Simulations 6 Conclusions and Perspectives References Turbulent Hydrogen Flames: Physics and Modeling Implications 1 Introduction 2 Turbulent Regime Diagram 3 Governing Equations 4 Turbulent Flame Speed 4.1 Global Turbulent Flame Speed 4.2 Local Flame Displacement Speed 5 Flamelet and PDF Modeling 6 Summary, Additional Challenges, and Future Prospects References Applications Hydrogen-Fueled Stationary Combustion Systems 1 Introduction: Challenges and Opportunities for Stationary Combustion Systems 2 State of the Art 2.1 Lab-Scale Systems: Understanding H2 Combustion Properties 2.2 Hydrogen in Quasi-Industrial Furnaces 2.3 Radiation 2.4 Hydrogen in Commercial and Industrial Systems 3 Numerical Modeling in Stationary Combustion Systems 3.1 Laboratory Scale Burners 3.2 Conditional Moment Closure models 3.3 Transported PDF Models 4 Numerical Studies on Industrial Configurations 5 Research Trends and Future Directions 5.1 Digital Twins 6 Conclusions References Hydrogen-Fueled Spark Ignition Engines 1 Introduction 2 The Properties of Hydrogen Relevant to SI Engine Operation 2.1 Physical and Chemical Properties of Hydrogen 2.2 Properties of Hydrogen Mixtures 2.3 Abnormal Combustion Phenomena 2.4 In-Cylinder Heat Transfer 3 Operating Strategies for Hydrogen SI Engines 3.1 Introduction: Hardware Choices 3.2 Power Density and Transient Response 3.3 Efficiency 3.4 Emissions 3.5 Trade-Offs 4 Past and Present R&D on Hydrogen SI Engines and Vehicles 4.1 Introduction 4.2 OEM Prototype Hydrogen Engines 4.3 Engine Components 4.4 Market Considerations 5 Conclusions and Outlook References Hydrogen Compression Ignition Engines 1 Introduction/Early Years 2 Challenges and Limitations 2.1 Single-fuel Operation 2.2 Energy Density 2.3 Abnormal Combustion 2.4 NOx Emissions 2.5 Incomplete Combustion at Low Loads 2.6 Safety 3 Engine Design/Modifications 3.1 Hydrogen Injection Systems 3.2 Other Modifications 4 Hydrogen as a Supplementary Fuel 4.1 Hydrogen-diesel Dual-fuel Engine 4.2 Hydrogen-biofuel Dual-fuel Engine 4.3 Alternative Hydrogen Substitution Systems 5 Combustion Control Strategies 5.1 Exhaust Gas Recirculation 5.2 Injection Strategies 5.3 Compression Ratio 5.4 Water Injection 5.5 Inert and Reactive Gas Dilution 6 Future Direction References Hydrogen Combustion in Gas Turbines 1 Introduction 2 Challenges with Hydrogen Gas Turbine Combustion Systems 2.1 Stabilisation and Flashback 2.2 Thermoacoustics 2.3 Nitrogen Oxides 2.4 Modelling 3 Future Prospects 4 Conclusions 5 Supplementary Material References Plasma-Assisted Hydrogen Combustion 1 Introduction 2 Chemistry and Dynamics of Plasma-Assisted Hydrogen Combustion 2.1 Chemistry of Plasma-Assisted Hydrogen Combustion 2.2 Dynamics of Plasma-Assisted Hydrogen Combustion 2.3 Plasma Thermal-Chemical Instability 3 Application of Plasma-Assisted Hydrogen Combustion in Advanced Thermal Engines 3.1 Plasma-Assisted Hydrogen Ignition 3.2 Application of Plasma-Assisted Hydrogen Combustion in Propulsion Systems 3.3 Deflagration to Detonation Transition 4 Summary and Future Research References Abnormal Combustion in Hydrogen-Fuelled IC Engines 1 Overview 2 Pre-ignition/Backfire 3 Knocking Combustion 4 Modelling Abnormal Combustion 5 Methods to Prevent Abnormal Combustion 6 Summary References Hydrogen Fueled Low-Temperature Combustion Engines 1 Introduction: Hydrogen-Fueled Low-Temperature Combustion Engine 2 Fuel Injection Strategy: HCCI and RCCI Combustion Mode 3 Hydrogen Fueled HCCI Engine 3.1 HCCI Engine: Performance and Combustion Characteristics 3.2 HCCI Engine: Emission Characteristics 4 Hydrogen-Fueled Dual-Fuel and RCCI Engine 4.1 Dual-Fuel and RCCI Engine: Performance Characteristics 4.2 Dual-Fuel and RCCI Engine: Combustion Characteristics 4.3 Dual-Fuel and RCCI Engine: Emission Characteristics 5 Challenges Associated with the Use of Hydrogen in HCCI and Dual-Fuel Engine 6 Future Prospects References Detonative Propulsion 1 Introduction 2 Types of Engines 2.1 Standing Detonation Wave Engines 2.2 RAMAC Accelerator 2.3 Pulsed Detonation Engine (PDE) 2.4 Rotating Detonation Engines (RDE) 3 Numerical Methods for Simulation of Detonation Engines 4 Application of Numerical Methods to Simulation of Detonation Engines 5 Future Application of Detonative Propulsion 6 Summary and Conclusions References