1、Technologies for Near-Zero-Emission Gasoline- Powered Vehicles Edited by Fuquan (Frank) ZhaoTechnologies for Near-Zero-Emission Gasoline-Powered VehiclesOther SAE titles of interest: Advanced Developments in Ultra-Clean Gasoline-Powered Vehicles By Fuquan (Frank) Zhao (Order No. PT-104) Automotive G
2、asoline Direct-Injection Engines By Fuquan (Frank) Zhao, David L. Harrington, and Ming-Chia Lai (Order No. R-315) Vehicular Engine Design By Kevin L. Hoag (Order No. R-369) For more information or to order a book, contact SAE International at 400 Commonwealth Drive, Warrendale, PA 15096-0001; phone
3、(724) 776-4970; fax (724) 776-0790; e-mail CustomerServicesae.org; website http:/store.sae.org.Technologies for Near-Zero-Emission Gasoline-Powered Vehicles Fuquan (Frank) Zhao SAE International Warrendale, Pa. Copyright 2007 SAE International eISBN: 978-0-7680-4301-3All rights reserved. No part of
4、this publication may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means, electronic, mechani- cal, photocopying, recording, or otherwise, without the prior written permission of SAE. For permission and licensing requests, contact: SAE Permissions 400 Commonwealt
5、h Drive Warrendale, PA 15096-0001 USA E-mail: permissionssae.org Tel: 724-772-4028 Fax: 724-772-3036 Library of Congress Cataloging-in-Publication Data Zhao, Fuquan. Technologies for near-zero-emission gasoline-powered vehicles / Fuquan (Frank) Zhao. p. cm. Includes bibliographical references and in
6、dex. ISBN-13: 978-0-7680-1461-7 ISBN-10: 0-7680-1461-1 1. Automobiles-Motors-Technological innovations. 2. Internal combustion engines, Spark ignition-Technological innovations. I. Title. TL210.Z454 2007 629.2504-dc22 2006040905 SAE International 400 Commonwealth Drive Warrendale, PA 15096-0001 USA
7、E-mail: CustomerServicesae.org Tel: 877-606-7323 (inside USA and Canada) 724-776-4970 (outside USA) Fax: 724-776-0790 Copyright 2007 SAE International ISBN-10 0-7680-1461-1 ISBN-13 978-0-7680-1461-7 SAE Order No. R-359 Printed in the United States of America.Contents Preface xv Chapter 1 Transient E
8、ngine Startup and Shutdown Processes 1 By Wai K. Cheng 1.1 Introduction 1 1.2 The Engine Shutdown Process for Port Fuel Injected Engines 2 1.2.1 General Behavior During the Shutdown Process 2 1.2.2 Impact of the Shutdown Process on Hydrocarbon Emissions 4 1.3 The Engine Startup Process for Port Fuel
9、 Injected Engines 5 1.3.1 Initial Conditions for Engine Startup 5 1.3.2 General Behavior During the Startup Process 6 1.3.3 Mixture Preparation in the Startup Transient 10 1.3.4 Combustion in the Startup Transient 20 1.3.5 Hydrocarbon Emissions in the Startup Transient 20 1.4 The Engine Startup Proc
10、ess for Direct Injection Spark Ignition Engines 22 1.5 Summary 25 1.6 References 26 Chapter 2 Mixture Formation Processes 31 By Ron Matthews and Matt Hall 2.1 Introduction 31 2.2 Liquid Fuel as a Source of Hydrocarbon Emissions 32 2.3 Fuel Injection Hardware and Controls 44 2.3.1 Injector Types 44 v
11、Near-Zero-Emission Gasoline-Powered Vehicles 2.3.2 Injection Timing 47 2.3.3 Other Injection Parameters 51 2.4 Flow Field Effects 56 2.5 Strategies to Improve Fuel Preparation and Reduce Liquid Fuel Effects During Cold Start and Warm-Up .60 2.6 Summary 64 2.7 References 69 Chapter 3 Cold-Start Hydro
12、carbon Emissions Mechanisms 79 By James A. Eng 3.1 Introduction 79 3.2 Global Engine Behavior During a Cold Start. 80 3.2.1 Required Fueling Levels 83 3.2.2 Fuel Accounting 84 3.3 Hydrocarbon Storage Mechanisms 86 3.3.1 Storage in Crevices 88 3.3.2 Absorption in Oil Layers and Deposits 90 3.3.3 Liqu
13、id Fuel 92 3.3.4 Quench Layers 96 3.3.5 Partial Burns 98 3.3.6 Rich Air/Fuel Operation 100 3.4 Hydrocarbon Transport Mechanisms 100 3.4.1 Transport Mechanisms at Warm Conditions 101 3.4.2 Transport Mechanisms at Cold Conditions 103 3.5 Hydrocarbon Oxidation 104 3.5.1 Hydrocarbon Oxidation Mechanisms
14、 105 3.5.2 Hydrocarbon Consumption Rates 106 3.5.3 Post-Flame Hydrocarbon Consumption in Engines .109 3.6 Summary. 112 3.7 References 114 viContents Chapter 4 Characterization of Cold Engine Processes . 121 By Choongsik Bae 4.1 Introduction 121 4.2 Fuel Injection Characteristics and Fuel Delivery in
15、to the Engine Cylinder 122 4.2.1 Fuel Sprays 122 4.2.2 Wall Wetting 127 4.2.3 Fuel Delivery into the Engine Cylinder 130 4.3 Mixture Distribution and Its Interaction with Flow 134 4.4 Combustion Processes and Pollutant Formation 142 4.5 Summary 145 4.6 References 146 Chapter 5 Spark Retardation for
16、Improving Catalyst Light-Off Performance. .157 By Stephen Russ 5.1 Introduction 157 5.2 Calibration Actions for Improving Catalyst Light-Off. 157 5.3 Engine Operation with Retarded Ignition 160 5.4 Approaches for More Robust Operation with Ignition Retard 163 5.4.1 Enhanced Charge Motion 163 5.4.2 D
17、ual Spark Ignition 167 5.5 Summary 168 5.6 References 169 Chapter 6 Secondary Air Injection for Improving Catalyst Light-Off Performance 173 By Fuquan (Frank) Zhao and Mark Borland 6.1 Introduction 173 6.2 Principle and System Layout of Secondary Air Injection 174 viiNear-Zero-Emission Gasoline-Powe
18、red Vehicles 6.3 Thermal Oxidation Versus Catalytic Oxidation 178 6.4 Role of Temperature and Mixing in Enhancing the Thermal Oxidation Process . 181 6.5 Requirements for Engine Enrichment and Secondary Air Injection Quantity 191 6.6 Secondary Air Injection Control and Onboard Diagnostics.193 6.6.1
19、Open-Loop Control 194 6.6.2 Closed-Loop Control 194 6.6.3 Sensors for Feedback Control 196 6.7 Other Application Considerations for Secondary Air Injection 197 6.7.1 Application of Secondary Air Injection to Vee Engines 197 6.7.2 Application of Secondary Air Injection to Turbocharged Engines 198 6.7
20、.3 Other Application Issues 199 6.8 Summary 200 6.9 References 201 Chapter 7 Effects of Fuel Properties and Fuel Reforming on Cold-Start Hydrocarbon Emissions and Catalyst Light-Off .205 By James A. Eng 7.1 Introduction 205 7.2 Gasoline Properties .207 7.2.1 Composition .207 7.2.2 Volatility 208 7.2
21、.3 Driveability 211 7.2.4 Reformulated Gasoline 214 7.3 Fuel Effects on Hydrocarbon Emissions 215 7.4 Onboard Fuel Reformers 220 7.4.1 Steam Reforming 222 viiiContents 7.4.2 Partial Oxidation Reforming 223 7.4.3 Autothermal Reforming 225 7.4.4 Cold-Start Performance Improvements 226 7.4.5 Improved C
22、atalyst Light-Off 227 7.4.6 Cold-Starting Alcohol-Fueled Vehicles. 228 7.5 Onboard Fuel Distillation 229 7.6 Summary 233 7.7 References 234 Chapter 8 Advanced Catalyst Design 241 By Paul J. Andersen, Todd H. Ballinger, and David S. Lafyatis 8.1 Introduction 241 8.2 Advanced Three-Way Catalyst Concep
23、ts and Design 247 8.3 Catalyst System Design Principles for Meeting Partial Zero Emissions Vehicle Emissions Standards 255 8.4 Summary .263 8.5 References 264 Chapter 9 The Hydrocarbon Trap 269 By Kimiyoshi Nishizawa 9.1 Introduction 269 9.2 Functions of the Hydrocarbon Trap 269 9.2.1 Hydrocarbon Tr
24、ap System 269 9.2.2 Materials 270 9.3 Factors to Control Efficiency 272 9.3.1 Selecting and Developing Trapping Material 273 9.3.2 Selecting and Developing the Catalyst Coating.275 9.3.3 Selecting the Shape of the Catalyst Substrate 276 9.4 Measures for Improving System Efficiency 277 ixNear-Zero-Em
25、ission Gasoline-Powered Vehicles 9.4.1 Actively Controlled Systems 277 9.4.2 Improved Passive Systems 279 9.5 Summary 281 9.6 References 281 Chapter 10 Three-Way Catalytic Converter System Modeling 283 By Tariq Shamim 10.1 Introduction. 283 10.2 Modeling Approaches 284 10.2.1 Single-Channel-Based On
26、e-Dimensional Modeling284 10.2.2 Multidimensional Modeling 286 10.3 Chemical Reaction Mechanisms 289 10.3.1 Three-Step Chemical Reaction Mechanism 290 10.3.2 Four-Step Chemical Reaction Mechanism.291 10.3.3 Modified Four-Step Chemical Reaction Mechanism 292 10.3.4 Five-Step Chemical Reaction Mechani
27、sm 292 10.3.5 Six-Step Chemical Reaction Mechanism 294 10.3.6 Thirteen-Step Chemical Reaction Mechanism. 296 10.3.7 Multistep Chemical Reaction Mechanism with Elementary Reaction. 297 10.3.8 Influence of Catalyst Deactivation on Reaction Mechanism 298 10.4 Oxygen Storage Mechanism 299 10.4.1 Simple
28、Single-Step Oxygen Storage Capacity Mechanism. 299 10.4.2 Detailed Nine-Step Oxygen Storage Capacity Mechanism 301 10.5 Heat and Mass Transfer Phenomena 302 10.6 Inlet Flow Distribution .304 10.6.1 Flow Distribution Index 308 10.6.2 Improvement of Flow Uniformity 309 xContents 10.7 Modeling of Catal
29、yst Dynamic Behavior. 309 10.8 Summary 313 10.9 Mathematical Nomenclature 317 10.10 References 320 10.11 Appendix .328 Chapter 11 Evaporative Emissions Reduction 333 By Jenny Spravsow and Christopher Hadre 11.1 Introduction 333 11.1.1 Overview of Evaporative Emissions Standards 333 11.1.2 Types of E
30、vaporative Emissions .334 11.1.3 Evaporative Emissions Test Procedures 334 11.2 Types of Evaporative Emissions Control Systems 336 11.3 Reducing Evaporative Emissions 337 11.3.1 Seals .339 11.3.2 Connectors 340 11.3.3 Materials 340 11.3.4 Canister and Engine Control Technology 342 11.4 Summary 345 1
31、1.5 References 345 Chapter 12 Onboard Diagnostics. 347 By Glenn Zimlich, Kathleen Grant, and Timothy Gernant 12.1 Introduction .347 12.1.1 Emissions Failure Thresholds for Diagnostic Monitors 348 12.1.2 Proper Identification of Diagnostic Failures .350 12.2 Catalyst System Monitor 351 12.2.1 Theory,
32、 Application, and Regulatory Implications 351 12.2.2 Catalyst Monitor Operation 353 12.3 Comprehensive Component Monitor. 354 xiNear-Zero-Emission Gasoline-Powered Vehicles 12.4 Cold-Start Emissions Reduction Control Strategy Monitor 354 12.5 Engine Misfire Monitor 355 12.5.1 Theory, Application, an
33、d Regulatory Implications 355 12.5.2 Misfire Monitor Operation 356 12.6 Evaporative System Monitor. 356 12.6.1 Theory, Application, and Regulatory Implications 356 12.6.2 Initial Vacuum Decay-Based Method for Leak Detection 356 12.6.3 Positive Pressure Decay Leak Detection .358 12.6.4 Natural Vacuum
34、-Based Leak Detection 358 12.7 Exhaust Gas Recirculation System Monitor 360 12.8 Fuel System Monitor 360 12.8.1 Theory, Application, and Regulatory Implications 360 12.8.2 Fuel System Monitor Operation .361 12.9 Oxygen Sensor Monitor 363 12.9.1 Theory, Application, and Regulatory Implications.363 12
35、.9.2 Oxygen Sensor Monitor Operation 363 12.10 Secondary Air System Monitor 364 12.11 Variable Valve Timing/Control System Monitor. .364 12.12 In-Use Performance Tracking 365 12.13 Summary 366 12.14 References 367 Chapter 13 Emissions Measurements. 369 By Michael Akard 13.1 Introduction 369 13.2 Exh
36、aust Emissions. 370 13.3 Constant Volume Sampler 372 13.3.1 Dilution Air. 372 13.3.2 Exhaust Dilution 375 13.3.3 Dilution Ratio Optimization. 376 xiiContents 13.3.4 Bag Sampling 376 13.3.5 Bag Materials 379 13.3.6 Flow Rate Measurement and Control 382 13.3.7 Sample Transfer from Bags to Analyzers 38
37、3 13.4 Bag Mini-Diluter 384 13.4.1 Bag Mini-Diluter Dilution Gas. 389 13.4.2 Oxygen Interference 394 13.4.3 Modeled Performance for Sampling Systems 396 13.4.4 Differences Among Bag Mini-Diluters 396 13.4.5 System Verification 397 13.5 Analyzer Accuracy 398 13.5.1 Calibration Gas Requirements 399 13
38、.5.2 Utilities and System Components 400 13.6 Summary 401 13.7 References 402 Chapter 14 Near-Zero-Emission Gasoline-Powered Vehicle Systems 407 By Fuquan (Frank) Zhao 14.1 Introduction 407 14.2 System Requirements for a Near-Zero-Emissions Gasoline-Powered Vehicle 408 14.3 BMW Partial Zero Emission
39、s Vehicle System 410 14.4 Ford Partial Zero Emissions Vehicle System 411 14.5 Honda Ultra-Clean Gasoline-Powered Vehicle System 413 14.6 Nissan Partial Zero Emissions Vehicle System 416 14.7 Toyota Partial Zero Emissions Vehicle System 424 14.8 Toyota Ultra-Clean Hybrid Vehicle System 428 14.9 Summa
40、ry 432 14.10 References 432 xiiiNear-Zero-Emission Gasoline-Powered Vehicles Acronyms 435 Index . 443 About the Contributing Authors . .457 About the Editor .463 xivPreface During the last several years, significant efforts have been directed toward the development of near-zero-emissions gasoline-po
41、wered vehicles in the automotive industry to meet increasingly stringent emissions legislation. Sev- eral vehicle manufacturers have already successfully launched these types of vehicles that are powered by conventional internal combustion engines and are certified in California to meet the most dif
42、ficult emissions standard of partial zero emissions vehicle (PZEV) in the world. Accompanying this extensive development effort is the continuing generation of a large volume of technical information, with a growing need for systematic organization, description of fundamental processes, sorting of i
43、nsights on technical issues, and identification of key trends and future research and development (R&D) directions. This book was planned to serve this essential purpose. Subjects related to the development and certification of near-zero-emissions gasoline-powered vehicles are covered in this book.
44、Experts in the field were invited to address a broad spectrum of key R&D issues in the rapidly progress- ing area of near-zero-emissions gasoline-powered vehicles. The book presents nearly all topics that a reader in the field may wish to comprehend, and future technology directions and R&D needs ar
45、e outlined. The purpose is to provide the reader with a concise, brief introduction to the state of the art of technology developments in near-zero-emissions gasoline-powered vehicles. The mate- rial reflects the latest global technical initiatives that are being incorporated or investigated within
46、the automotive and research communities. Engineers and researchers in this field will find the book invaluable in developing optimum systems for near-zero-emissions gasoline-powered vehicles and in understand- ing and interpreting test data. Corporate managers who are responsible for product decisio
47、ns in this area will benefit significantly from the clear statements of the advantages and disadvantages of a spectrum of subsystems and from the discussions of current global best practices. This book is organized into 14 chapters. The complex processes associated with engine startup and shutdown,
48、mixture formation, unburned hydrocarbon (HC) emissions formation, and characterization of cold engine processes are presented in Chapters 1 through 4 in a clear and organized manner, and are placed within a framework of current state-of-the-art hardware and processes. Chapters 5 through 7 describe i
49、n detail the key technologies for improving cold-start xvNear-Zero-Emission Gasoline-Powered Vehicles catalyst light-off performance, such as spark retardation, secondary air injec- tion, fuel properties, and fuel reforming. Chapter 8 describes state-of-the-art catalyst developments in meeting the most stringent emissions regulations such as PZEV. Chapter 9 is dedicated to the development of HC traps for control- ling cold-start HC emissions. Chapter 10 introduces approaches developed to systematically model three-way catalytic converters, and Chapter 11 outlines the measures rec
