Handbook of Thermal Management of Engines (Energy, Environment, and Sustainability)

This handbook deals with the vast subject of thermal management of engines and vehicles by applying the state of the art research to diesel and natural gas engines. The contributions from global experts focus on management, generation, and retention of heat in after-treatment and exhaust systems for light-off of NOx, PM, and PN catalysts during cold start and city cycles as well as operation at ultralow temperatures. This book will be of great interest to those in academia and industry involved in the design and development of advanced diesel and CNG engines satisfying the current and future emission standards. Preface Contents Editors and Contributors Part I The Gestalt of Thermal Management 1 Introduction to Thermal Management Techniques 1.1 Background 1.1.1 Engine Cooling System 1.2 Engine Lubrication System 1.3 Combustion System 1.3.1 Thermal Management for After-Treatment 1.3.2 Cylinder Gas Exchange Control 1.3.3 Post Fuel Injection 1.4 Cylinder Deactivation (CDA) 1.5 Waste Heat Recovery (WHR) 1.6 Thermal Management Assessment by Simulation 1.6.1 Case Study I—On-Road Heavy Duty Application 1.6.2 Case Study II—Off-Road Application 1.7 Summary Appendix: WHSC and WHTC References 2 Thermal Management of Exhaust Aftertreatment for Diesel Engines 2.1 Introduction 2.2 Need for Aftertreatment Thermal Management 2.2.1 Regulatory Requirements 2.2.2 Catalyst Performance 2.3 Aftertreatment Recovery 2.3.1 Diesel Particulate Filter (DPF) Regeneration 2.3.2 Catalyst Recovery 2.3.3 Diesel Exhaust Fluid (DEF) Dosing and SCR Solid Deposits 2.3.4 Aftertreatment Packaging Requirements 2.4 Engine-Based Thermal Management 2.4.1 Active Duty Cycle Adjustment 2.4.2 In-Cylinder Post-Injection of Fuel 2.4.3 Cylinder Deactivation 2.4.4 Exhaust Restriction or Intake Throttling 2.4.5 Combustion and Fuel Strategies 2.5 Aftertreatment Fuel Introduction 2.5.1 DOC Light off and Quenching 2.5.2 DOC Degradation 2.5.3 DPF Temperature Gradients During Active Regeneration 2.5.4 Hydrocarbon Injector Selection 2.6 Heat Generation 2.6.1 Burner Device 2.6.2 Electric Heater 2.6.3 Microwave Heater 2.6.4 Plasma Burner 2.6.5 Aftertreatment Heat Retention 2.6.6 Insulation and Aftertreatment Design 2.6.7 Close-Coupled and Pre-turbo Aftertreatment Designs 2.6.8 Use of Phase Change Materials 2.7 Exhaust Heat Management 2.7.1 Waste Heat Recovery 2.7.2 Maximum Exhaust Temperature Threshold 2.7.3 Hybrids and Alternative Propulsion Systems 2.8 Summary References Part II Thermal Management Through Turbocharging and Insulation Between Aftertreatment Systems and the Engine 3 Models for Instantaneous Heat Transfer in Engines and the Manifolds for 1-D Thermodynamic Engine Simulation 3.1 Introduction 3.2 Model for Heat Transfer from Turbocharger 3.3 Models for Heat Transfer: Ports, Intake and Exhaust Lines, Cylinders and Pistons 3.3.1 Calculation of Wall Temperature 3.3.2 Validation of Heat Transfer Model 3.4 Parametric Studies 3.4.1 Length and Distribution of Exhaust Ports 3.4.2 Valves and Ports Diameter 3.4.3 Exhaust Valve Timing 3.4.4 Multi-step Valve Opening 3.5 Conclusions 3.6 Appendix 1: Potential of different designs of exhaust manifolds in saving thermal Energy for transient Performance 3.7 Synthesis of Different Designs References 4 Variable Geometry Turbocharger Technologies for Exhaust Energy Recovery and Boosting 4.1 Supercharging and Turbocharging 4.2 Types of Turbocharger 4.3 Turbocharger Construction 4.4 Engine and Turbocharger: Performance Characteristics 4.4.1 Engine Torque and Brake Mean Effective Pressure 4.4.2 Engine Air Mass Flow Rate 4.4.3 Brake Specific Fuel Consumption 4.4.4 Smoke Emission 4.4.5 Compressor Characteristics 4.4.6 Turbine Characteristics 4.5 Thermal Management of the Exhaust Treatment System 4.5.1 Cold Start 4.5.2 Optimized Turbine Housing and Wastegate Port 4.5.3 Turbine By-Pass with Fixed Turbine Geometry (FTG) 4.5.4 Opening of the Nozzle Vanes of VTG 4.5.5 Combination of VTG and External By-Pass 4.5.6 Inner Thermal Insulation of Turbine Housing 4.5.7 Outer Thermal Insulation of Turbine Housing and Exhaust Manifold 4.5.8 Air Gap Insulated Exhaust Manifold and Turbine Housing 4.5.9 Integration of Turbine Housing with Exhaust Manifold 4.5.10 Exhaust After-Treatment System Before the Turbine 4.6 Summary References 5 Thermal Management Through Insulation Design—Passenger Car Platforms 5.1 Introduction 5.2 Thermal Insulation Design Consideration 5.3 Insulation Applicability Criteria 5.4 Modes of Heat Transfer in Typical Hot Spot Areas 5.5 Heatshield Applications 5.6 Types of Heat Shields Based on Design 5.7 Heat Shield Application: Area and Types 5.7.1 Engine Compartment Area 5.8 Protection Against Heat: “Hot-Spot” 5.9 Thermal Mapping for Design Validation 5.9.1 Mapping Surfaces Using a Thermal Camera 5.9.2 Mapping Temperature of Flows and Surfaces Using Thermocouples 5.10 Assembly of Heatshields References Part III Techniques for Early Light-Off of Aftertreatment Systems 6 Diesel Engine Throttling—The Classical Tool: To Adapt Exhaust Gas Temperature for Emission Control by Catalysts and Filters: From Its Beginning to the State of the Art in Euro 6/VI 6.1 Part 1: Temperature Management by Throttling 6.1.1 Introduction 6.1.2 Regeneration Requirements 6.1.3 Current Systems 6.1.4 Concept of Intake Throttling 6.1.5 Computational Simulation 6.1.6 Experimental Verification 6.1.7 Concepts of Control 6.1.8 Aspects of Design 6.1.9 Final Remarks 6.2 Part 2: Retrofitting TRU-Diesel Engines with DPF-Systems Using FBC and Intake Throttling for Active Regeneration 6.2.1 Introduction 6.2.2 TRU Design and Operation Conditions 6.2.3 Emission Reduction Objectives 6.2.4 Test Cycle 6.2.5 Reducing Emissions 6.2.6 Regeneration 6.2.7 Conclusions 6.3 Part 3: Retrofit Kit to Reduce NOx and PM Emissions from Diesel Engines Using a Low-Pressure EGR and a DPF System with FBC and Throttling for Active Regeneration Without Production of Secondary Emissions 6.3.1 Introduction 6.3.2 Regulation 6.3.3 DPF Regeneration 6.3.4 The Focus of This Investigation 6.3.5 Evaluation of the Optimal Setup 6.3.6 Result of the Steady State Measurements 6.3.7 NOx Reduction Due to EGR 6.3.8 Components and Sub-systems of the Retrofit Kit 6.3.9 Steady State Investigation of the Retrofit Kit 6.3.10 Control Approach 6.3.11 Intake Throttling to Control DPF Regeneration 6.3.12 Regeneration Strategy 6.3.13 Dynamic Tests 6.3.14 Conclusion 6.4 Part 4: State of the Art of Throttling Diesel Intake Air or Exhaust Gas in Euro VI Vehicles—The Result of 20 Years Pioneering Now the Indispensable Part of Emission Control 6.4.1 Introduction 6.4.2 Temperature Profiles During Drive Cycles 6.4.3 Design of the Throttle Valves 6.4.4 Catalytic Combustion of Injected Fuel to Further Increase the Gas Temperature 6.4.5 Combination of SCR and DPF with Thermal Management References 7 Decoupling Temperature and Oxygen for DPF Regeneration 7.1 Important Parameters for the Regeneration of Soot-Laden DPFs 7.2 Shortcomings of Existing Systems 7.2.1 Engine-Internal Post-injection 7.2.2 Injection After the Engine 7.2.3 Static Throttling 7.2.4 Dynamic Throttling 7.3 Software to Investigate the Transient Temperature Behavior 7.4 Technical Solutions That Already Use This Approach References 8 Thermal Management of the DPF, DOC, and SCR Processes by Heat Recovery 8.1 Low Temperatures at Urban Driving Conditions Create a Fundamental Problem 8.2 The Heat Recovery Approach, Still not Widely Used Provides an Option 8.3 Solution by a Heat Source Within the Recovery Loop 8.4 Conceivable Heat Recovery Options 8.4.1 Predecessors of Heat Recovery Applications 8.4.2 Vehicle Gas Turbine 8.4.3 QuadCAT 8.4.4 Particle Filter Regeneration 8.4.5 EMITEC-DOC-Recuperator 8.5 Further Elements to be Applied with Heat Recovery for Exhaust Gas After Treatment 8.5.1 Urea Mixing 8.5.2 Urea Deposition and Crystallization 8.5.3 Downstream Ammonia-Slip Catalyst ASC at a High-Temperature Level 8.5.4 Control for Minimum Energy Demand 8.5.5 Staged DPF Regeneration 8.5.6 SDPF References 9 Evaluation of Next-Generation SCR Concepts for Heavy-Duty Applications by Using Catalytic Simulation 9.1 Introduction 9.1.1 Heavy-Duty NOxEmission Regulations 9.1.2 NOxControl Technologies (EGR Versus SCR) 9.1.3 Current Trends in Heavy-Duty Diesel Engine and SCR System 9.1.4 The Perspective of Next-Generation SCR Technology 9.1.5 Use of Catalytic Simulation in the Design of SCR Systems 9.1.6 Next-Generation SCR Concepts Studied in This Article 9.1.7 Next-Generation NOxReduction Target 9.2 Catalytic Simulation of SCR System 9.2.1 Modeling of Ammonia Adsorption/desorption 9.2.2 Modeling of SCR Reactions 9.2.3 Kinetic Parameter Calibration 9.3 The Emissions Test Result of the Baseline SCR System 9.3.1 Validation of SCR Simulation Model 9.4 Evaluation of Next-Generation SCR Concepts 9.4.1 Simulation Result of ‘New ATS Layout #1’ Concept 9.4.2 Simulation Result of ‘New ATS Layout #2’ Concept References Part IV The Methane Conundrum 10 Cold Phase Methane Emissions, a Challenge to Overcome in Spark Ignited Natural Gas Engines 10.1 Introduction 10.2 Emission Cycles and Bharat Stage 6 and 4 Standards 10.2.1 BS4 10.2.2 BS6 10.3 Cold Start Emissions 10.3.1 Sources of Unburned Hydrocarbons 10.3.2 Factors Affecting UHC in the Cylinder 10.3.3 Factors After the Cylinder 10.3.4 Treating Cold Start HC Emissions 10.4 After-Treatment of Methane 10.4.1 Catalytic Light-Off Temperature 10.5 Strategies to Minimise the Cold Start Methane Emissions 10.5.1 Catalytic Converter 10.5.2 Mixture Control 10.6 Summary References Part V Simulation of Heat Under Body and Hood 11 Cooling System Study and Simulation 11.1 Introduction 11.2 Automotive Cooling System 11.2.1 Cooling System Layout and Components 11.2.2 DAT 11.2.3 Coolant Pump 11.2.4 Heat Exchangers 11.2.5 Engine Water Jacket 11.2.6 Thermostat 11.2.7 Valves, Pipes, and Hoses 11.2.8 Fan 11.3 Operating Conditions 11.4 Heat Transfer in Engines and Influencing Factors 11.5 Modes of Heat Transfer in Engine Cooling System 11.5.1 Conduction 11.5.2 Convection 11.5.3 Radiation 11.6 Design Considerations in the Cooling System 11.7 Computational Fluid Dynamics 11.8 Forms of NSE 11.9 DNS 11.10 RANS 11.10.1 Spalart Allmaras Model 11.10.2 Two Equation Models 11.10.3 Wall Treatment 11.11 Large Eddy Simulation 11.12 Detached Eddy Simulation (DES) 11.13 Gridless Methods 11.13.1 SPH 11.14 LBM 11.15 Heat Transfer Models in CFD 11.16 Convection Heat Transfer in Turbulent Flows 11.17 Conjugate Heat Transfer (CHT)—Coupled Conduction and Convection 11.18 Boiling Models 11.18.1 Significant Properties of Coolant 11.18.2 Boiling Model for Coolant Flow 11.19 Radiation Model 11.20 Component Specific CFD Models 11.20.1 Fan Model 11.20.2 Heat Exchanger 11.21 Mesh Generation 11.21.1 Geometry Clean-Up 11.21.2 Structured Mesh 11.21.3 Unstructured Mesh 11.21.4 Mesh Element Types and Uses 11.21.5 Advancing Front Method [67] 11.21.6 Delaunay Triangulation Method [68] 11.21.7 Cartesian and Octree Methods [72] 11.21.8 Mesh Quality 11.22 Parallel Computing 11.22.1 Speed and Scalability 11.22.2 Partitioning 11.22.3 Partitioning Methods 11.22.4 Parallel Processing 11.22.5 Parallel Grid Generation/post-Processing 11.23 Common CFD Analyses for Automotive Cooling System 11.23.1 Underhood Analysis 11.23.2 Coolant Flow Analysis 11.24 Optimization 11.24.1 Formulation of the Optimization Problem 11.24.2 Optimization Algorithms 11.24.3 Gradient-Based Algorithms 11.24.4 Genetic Algorithm 11.24.5 Surrogate Models 11.25 Design Modification for Analysis 11.25.1 CAD Level Modifications 11.25.2 Mesh Morphing References 12 Estimation of Skin Temperature on Surfaces of Exhaust Line 12.1 Introduction 12.2 Heat Transfer in Pipe Flow 12.3 Numerical Methods for General Flow Solution 12.3.1 Historical Explicit Methods 12.4 Examples 12.5 Application of the Finite Difference Scheme to Engines 12.5.1 Wall Thermal Solution Considering Heat Transfer External to the Pipe 12.6 1-D Model 12.7 Results and Discussion 12.7.1 Transient Simulation 12.8 Skin Temperature Estimation Coupling 1-D Model and Vehicle Level 3-D Model 12.8.1 3-D Steady-State Simulation Setup 12.8.2 Parametric Study Involving the Effect of External Emissivity 12.9 Summary References 13 The Role of Computational Fluid Dynamics in Designing Thermally Safe Vehicles in a Competitive and Aggressive Development Landscape 13.1 Introduction 13.2 Simulation Workflows 13.3 Simulation Numerics 13.4 Simulation Methodology 13.5 Cooling Airflow 13.6 The Challenges of Underhood Cooling 13.7 Methodology Description 13.7.1 Fan Modeling 13.7.2 Sliding Mesh 13.7.3 Multiple Reference Frame (MRF) 13.7.4 In-Line Fan Model 13.7.5 Heat Exchanger Modeling 13.8 Example Workflow 13.8.1 Underhood Cooling (UHC) App 13.8.2 Denso Engine Cooling Module (ECM) Digital Library 13.9 Thermal Protection 13.10 Turbulence Modelling 13.11 Radiation Modelling 13.12 Conduction Modelling 13.13 Thermal Transient 13.14 Key-Off/Soak 13.15 Significance of Key-Off/Soak 13.16 Soak Methodology 13.17 Key-Off/Soak Workflow Example 13.18 Idle 13.19 Thermal Drive Cycle 13.20 Thermal Drive Cycle Workflow Example 13.21 Automation of Simulation Process 13.21.1 Model Geometry 13.21.2 Material Properties 13.21.3 Sub-System Properties 13.21.4 Boundary Conditions 13.21.5 Discretized Model 13.21.6 Solver Parameters 13.21.7 Simulation Result 13.21.8 Extension to Design Process 13.22 Optimization for Engine Thermal Management 13.23 Example 1: Cooling Module Layout Design for Cooling Efficiency and Aerodynamic Performance 13.24 Example 2: Car Body Design Optimization for Cooling Efficiency and Aerodynamic Performance 13.25 Example 3: Active Grille Shutters (AGS) Optimization for Fuel Economy 13.26 Post-processing of Simulation Results 13.27 System Modeling 13.27.1 System Simulation with the Modelica Open Standard 13.27.2 Systems Integration with FMI Open Standard 13.28 System Model Objective 13.28.1 Heat Rejection Capacity 13.28.2 Coolant Temperature 13.28.3 Engine Efficiency 13.28.4 Cooling Power Consumption 13.28.5 Packaging 13.28.6 Aerodynamic Efficiency 13.28.7 Cabin Heater Performance 13.28.8 Weight and Cost 13.29 Methodology 13.29.1 General Modeling Principle 13.29.2 Important Components 13.29.3 Heat Exchangers 13.29.4 Fan 13.29.5 Pump 13.29.6 Pipe 13.29.7 Valves 13.30 Design Example 13.30.1 Example Models 13.30.2 Architecture Design and Trade-Off 13.30.3 Component Design and Trade-Off 13.30.4 Part Selection and Sizing 13.30.5 Heat Exchanger Stacking 13.30.6 Integration and Calibration References Part VI Fuels, Oils and Equipment for Managing at Ultra-Low Temperatures 14 Low-Temperature Operation: Fuels and Lubricants for Cold Temperature Regions 14.1 Introduction 14.2 Cold Start Behaviour of Internal Combustion Engines 14.3 Fuels for Winter Regions 14.3.1 Winter Fuel Development 14.4 Engine Oils for Winter Regions 14.4.1 Engine Oil Classification 14.4.2 Properties of Engine Oils for Low Temperatures 14.5 Conclusion Appendix: Block Heater Circuit for Increasing Coolant Temperature at Cold Ambient References 15 Low-Temperature Operation: Impact of Cold Temperature on Euro 6 Passenger Car Emissions 15.1 Introduction 15.2 Experiments by Europe JRC 15.3 Comparison of WLTC Emissions at - 7 and 23 oC 15.3.1 THC and CO Emissions 15.3.2 NOx and NH3 Emissions 15.3.3 GHG Emissions 15.3.4 Particle Number 15.4 Conclusions Appendix: Summary of Experimental Results From Ref. [12] References