Lean Combustion

Lean Combustion

Author: Derek Dunn-Rankin

Publisher: Academic Press

Published: 2011-07-28

Total Pages: 282

ISBN-13: 0080550525

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Combustion under sufficiently fuel-lean conditions can have the desirable attributes of high efficiency and low emissions, this being particularly important in light of recent and rapid increases in the cost of fossil fuels and concerns over the links between combustion and global climate change. Lean Combustion is an eminently authoritative, reference work on the latest advances in lean combustion technology and systems. It will offer engineers working on combustion equipment and systems both the fundamentals and the latest developments in more efficient fuel usage and in much-sought-after reductions of undesirable emissions, while still achieving desired power output and performance. This volume brings together research and design of lean combustion systems across the technology spectrum in order to explore the state-of-the-art in lean combustion and its role in meeting current and future demands on combustion systems. Readers will learn about advances in the understanding of ultra lean fuel mixtures and how new types of burners and approaches to managing heat flow can reduce problems often found with lean combustion such as slow, difficult ignition and frequent flame extinction. The book will also offer abundant references and examples of recent real-world applications. Covers all major recent developments in lean combustion science and technology, with new applications in both traditional combustion schemes as well as such novel uses as highly preheated and hydrogen-fueled systems Offers techniques for overcoming difficult ignition problems and flame extinction with lean fuel mixtures Covers new developments in lean combustion using high levels of pre-heat and heat re-circulating burners, as well as the active control of lean combustion instabilities


Mixture Formation in Spark-Ignition Engines

Mixture Formation in Spark-Ignition Engines

Author: Hans Peter Lenz

Publisher: Springer

Published: 2013-11-11

Total Pages: 417

ISBN-13: 148992762X

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Twentyfour years have gone by since the publication of K. Lohner and H. Muller's comprehen sive work "Gemischbildung und Verbrennung im Ottomotor" in 1967 [1.1]' Naturally, the field of mixture formation and combustion in the spark-ignition engine has wit nessed great technological advances and many new findings in the intervening years, so that the time seemed ripe for presenting a summary of recent research and developments. There fore, I gladly took up the suggestion of the editors of this series of books, Professor Dr. H. List and Professor Dr. A. Pischinger, to write a book summarizing the present state of the art. A center of activity of the Institute of Internal-Combustion Engines and Automotive Engineering at the Vienna Technical University, which I am heading, is the field of mixture formation -there fore, many new results that have been achieved in this area in collaboration with the respective industry have been included in this volume. The basic principles of combustion are discussed only to that extent which seemect necessary for an understanding of the effects of mixture formation. The focal point of this volume is the mixture formation in spark-ignition engines, covering both the theory and actual design of the mixture formation units and appropriate intake manifolds. Also, the related measurement technology is explained in this work.


Assessment of Fuel Economy Technologies for Light-Duty Vehicles

Assessment of Fuel Economy Technologies for Light-Duty Vehicles

Author: National Research Council

Publisher: National Academies Press

Published: 2011-06-03

Total Pages: 373

ISBN-13: 0309216389

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Various combinations of commercially available technologies could greatly reduce fuel consumption in passenger cars, sport-utility vehicles, minivans, and other light-duty vehicles without compromising vehicle performance or safety. Assessment of Technologies for Improving Light Duty Vehicle Fuel Economy estimates the potential fuel savings and costs to consumers of available technology combinations for three types of engines: spark-ignition gasoline, compression-ignition diesel, and hybrid. According to its estimates, adopting the full combination of improved technologies in medium and large cars and pickup trucks with spark-ignition engines could reduce fuel consumption by 29 percent at an additional cost of $2,200 to the consumer. Replacing spark-ignition engines with diesel engines and components would yield fuel savings of about 37 percent at an added cost of approximately $5,900 per vehicle, and replacing spark-ignition engines with hybrid engines and components would reduce fuel consumption by 43 percent at an increase of $6,000 per vehicle. The book focuses on fuel consumption-the amount of fuel consumed in a given driving distance-because energy savings are directly related to the amount of fuel used. In contrast, fuel economy measures how far a vehicle will travel with a gallon of fuel. Because fuel consumption data indicate money saved on fuel purchases and reductions in carbon dioxide emissions, the book finds that vehicle stickers should provide consumers with fuel consumption data in addition to fuel economy information.


Renewable Hydrogen Technologies

Renewable Hydrogen Technologies

Author: Luis M Gandia

Publisher: Newnes

Published: 2013-05-03

Total Pages: 471

ISBN-13: 044456361X

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The fields covered by the hydrogen energy topic have grown rapidly, and now it has become clearly multidisciplinary. In addition to production, hydrogen purification and especially storage are key challenges that could limit the use of hydrogen fuel. In this book, the purification of hydrogen with membrane technology and its storage in "solid" form using new hydrides and carbon materials are addressed. Other novelties of this volume include the power conditioning of water electrolyzers, the integration in the electric grid of renewable hydrogen systems and the future role of microreactors and micro-process engineering in hydrogen technology as well as the potential of computational fluid dynamics to hydrogen equipment design and the assessment of safety issues. Finally, and being aware that transportation will likely constitute the first commercial application of hydrogen fuel, two chapters are devoted to the recent advances in hydrogen fuel cells and hydrogen-fueled internal combustion engines for transport vehicles. Hydrogen from water and biomass considered Holistic approach to the topic of renewable hydrogen production Power conditioning of water electrolyzers and integration of renewable hydrogen energy systems considered Subjects not included in previous books on hydrogen energy Micro process technology considered Subject not included in previous books on hydrogen energy Applications of CFD considered Subject not included in previous books on hydrogen energy Fundamental aspects will not be discussed in detail consciously as they are suitably addressed in previous books Emphasis on technological advancements Chapters written by recognized experts Up-to date approach to the subjects and relevant bibliographic references


Hydrogen Enrichment for the Extension of the Lean Limit and Enhanced Combustion in an Alcohol-fueled Spark-ignition Engine

Hydrogen Enrichment for the Extension of the Lean Limit and Enhanced Combustion in an Alcohol-fueled Spark-ignition Engine

Author: Jason Brian Greenwood

Publisher:

Published: 2011

Total Pages:

ISBN-13: 9781124907178

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An investigation was made to determine the effects of hydrogen enrichment in the lean combustion regime for ethanol and to determine if it could extend the lean operating limit for both ethanol and methanol. In this study, a 0.745 liter 2-cylinder Kawasaki engine was modified to operate with both alcohol and hydrogen fuels. Hydrogen concentrations of 0%, 15%, and 30% by volume hydrogen in the primary fuel were fumigated into the intake before the throttle; the engine was operated at 2000 RPM and part throttle. Data were collected to calculate NO and HC emissions, power, exhaust gas temperature, thermal efficiency, volumetric efficiency, brake-specific fuel consumption, and flame development and rapid burning angles. It was shown that hydrogen enrichment demonstrated an ability to not only decrease NO emissions, but also stabilize and accelerate the combustion process in the lean combustion regime. At a given equivalence ratio, hydrogen addition decreased NO emissions; this decrease was attributed to a change in dominate NO production mechanism(s) under lean operating conditions. Hydrogen enabled a marginal extension of the lean operating limit (LOL) for both fuels, with the potential of further extending the LOL if the stability criteria are changed. Hydrogen enrichment at both 15% and 30% by volume reduced engine-out NO emissions near the lean operating limit by more than 95% relative to stoichiometric ethanol operation while both the COV and HC emissions were kept low, making it a potentially competitive alternative to NO reduction through traditional three-way catalytic after-treatment. Power, thermal efficiency, and volumetric efficiency were not significantly affected by hydrogen addition at a given equivalence ratio; however, if hydrogen addition is used to decrease the lean operating limit, decreases in power and thermal efficiency were observed. Power in the lean combustion regime decreased by between 31 and 37% when compared to stoichiometric operation without hydrogen.