In-Cylinder Processes of High-EGR Low-Load Diesel Combustion PDF Download
Are you looking for read ebook online? Search for your book and save it on your Kindle device, PC, phones or tablets. Download In-Cylinder Processes of High-EGR Low-Load Diesel Combustion PDF full book. Access full book title In-Cylinder Processes of High-EGR Low-Load Diesel Combustion by . Download full books in PDF and EPUB format.
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 19
Get Book Here
Book Description
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 19
Get Book Here
Book Description
Author: P. A. Lakshminarayanan
Publisher: Springer Science & Business Media
ISBN: 904813885X
Category : Technology & Engineering
Languages : en
Pages : 313
Get Book Here
Book Description
Phenomenology of Diesel Combustion and Modeling Diesel is the most efficient combustion engine today and it plays an important role in transport of goods and passengers on land and on high seas. The emissions must be controlled as stipulated by the society without sacrificing the legendary fuel economy of the diesel engines. These important drivers caused innovations in diesel engineering like re-entrant combustion chambers in the piston, lower swirl support and high pressure injection, in turn reducing the ignition delay and hence the nitric oxides. The limits on emissions are being continually reduced. The- fore, the required accuracy of the models to predict the emissions and efficiency of the engines is high. The phenomenological combustion models based on physical and chemical description of the processes in the engine are practical to describe diesel engine combustion and to carry out parametric studies. This is because the injection process, which can be relatively well predicted, has the dominant effect on mixture formation and subsequent course of combustion. The need for improving these models by incorporating new developments in engine designs is explained in Chapter 2. With “model based control programs” used in the Electronic Control Units of the engines, phenomenological models are assuming more importance now because the detailed CFD based models are too slow to be handled by the Electronic Control Units. Experimental work is necessary to develop the basic understanding of the pr- esses.
Author: Marvin Sascha Wahl
Publisher: Springer Nature
ISBN: 3658420944
Category : Technology & Engineering
Languages : en
Pages : 152
Get Book Here
Book Description
Marvin Sascha Wahl presents the possibilities for optimising diesel engine combustion. In the advanced process of partially premixed diesel combustion, nitrogen oxide and soot emissions can be minimised at the same time. A new feature is the possibility of applying this strategy up to 2000 revolutions and 10 bar indicated mean pressure. In this work, various effective parameters are also compared and correlated with each other. A final comparison with conventional diesel combustion shows the advantages and disadvantages and evaluates them.
Author: Xavier Llamas
Publisher: Linköping University Electronic Press
ISBN: 9176853683
Category :
Languages : en
Pages : 48
Get Book Here
Book Description
The international marine shipping industry is responsible for the transport of around 90% of the total world trade. Low-speed two-stroke diesel engines usually propel the largest trading ships. This engine type choice is mainly motivated by its high fuel efficiency and the capacity to burn cheap low-quality fuels. To reduce the marine freight impact on the environment, the International Maritime Organization (IMO) has introduced stricter limits on the engine pollutant emissions. One of these new restrictions, named Tier III, sets the maximum NOx emissions permitted. New emission reduction technologies have to be developed to fulfill the Tier III limits on two-stroke engines since adjusting the engine combustion alone is not sufficient. There are several promising technologies to achieve the required NOx reductions, Exhaust Gas Recirculation (EGR) is one of them. For automotive applications, EGR is a mature technology, and many of the research findings can be used directly in marine applications. However, there are some differences in marine two-stroke engines, which require further development to apply and control EGR. The number of available engines for testing EGR controllers on ships and test beds is low due to the recent introduction of EGR. Hence, engine simulation models are a good alternative for developing controllers, and many different engine loading scenarios can be simulated without the high costs of running real engine tests. The primary focus of this thesis is the development and validation of models for two-stroke marine engines with EGR. The modeling follows a Mean Value Engine Model (MVEM) approach, which has a low computational complexity and permits faster than real-time simulations suitable for controller testing. A parameterization process that deals with the low measurement data availability, compared to the available data on automotive engines, is also investigated and described. As a result, the proposed model is parameterized to two different two-stroke engines showing a good agreement with the measurements in both stationary and dynamic conditions. Several engine components have been developed. One of these is a new analytic in-cylinder pressure model that captures the influence of the injection and exhaust valve timings without increasing the simulation time. A new compressor model that can extrapolate to low speeds and pressure ratios in a physically sound way is also described. This compressor model is a requirement to be able to simulate low engine loads. Moreover, a novel parameterization algorithm is shown to handle well the model nonlinearities and to obtain a good model agreement with a large number of tested compressor maps. Furthermore, the engine model is complemented with dynamic models for ship and propeller to be able to simulate transient sailing scenarios, where good EGR controller performance is crucial. The model is used to identify the low load area as the most challenging for the controller performance, due to the slower engine air path dynamics. Further low load simulations indicate that sensor bias can be problematic and lead to an undesired black smoke formation, while errors in the parameters of the controller flow estimators are not as critical. This result is valuable because for a newly built engine a proper sensor setup is more straightforward to verify than to get the right parameters for the flow estimators.
Author: National Research Council
Publisher: National Academies Press
ISBN: 0309216389
Category : Science
Languages : en
Pages : 373
Get Book Here
Book Description
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.
Author: Gautam Kalghatgi
Publisher: Springer Nature
ISBN: 9811687358
Category : Technology & Engineering
Languages : en
Pages : 339
Get Book Here
Book Description
This book focuses on gasoline compression ignition (GCI) which offers the prospect of engines with high efficiency and low exhaust emissions at a lower cost. A GCI engine is a compression ignition (CI) engine which is run on gasoline-like fuels (even on low-octane gasoline), making it significantly easier to control particulates and NOx but with high efficiency. The state of the art development to make GCI combustion feasible on practical vehicles is highlighted, e.g., on overcoming problems on cold start, high-pressure rise rates at high loads, transients, and HC and CO emissions. This book will be a useful guide to those in academia and industry.
Author: Jonathan Robert Breen
Publisher:
ISBN:
Category :
Languages : en
Pages :
Get Book Here
Book Description
Low temperature combustion (LTC) is an appealing new method of combustion that promises low nitric oxides and soot emissions while maintaining or improving on engine performance. The three main points of this study were to develop and validate an engine model in GT-Power capable of implementing LTC, to study parametrically exhaust gas recirculation (EGR) and injection timing effects on performance and emissions, and to investigate methods to decrease pressure rise rates during LTC operation. The model was validated at nine different operating points, 3 speeds and 3 loads, while the parametric studies were conducted on 6 of the 9 operating points, 3 speeds and 2 loads. The model consists of sections that include: cylinders, ports, intake and exhaust manifolds, EGR system, and turbocharger. For this model, GT-Power calculates the combustion using a multi-zone, quasi-dimensional model and a knock-induced combustion model. The main difference between them is that the multi-zone model is directly injected while the knock model is port injected. A variety of sub models calculate the fluid flow and heat transfer. A parametric study varying the EGR and the injection timing to determine the optimal combination was conducted using the multi-zone model while a parametric study that just varies EGR is carried out using the knock model. The first parametric study showed that the optimal EGR and injection timing combination for the low loads occurred at high levels of EGR (60 percent) and advanced injection timings (30 to 40 crank angle degrees before top dead center). The optimal EGR and injection timing combination for the high loads occurred at low levels of EGR (30 percent to 40 percent) and retarded injection timings (7.5 to 5 crank angle degrees before top dead center). The knock model determined that the ideal EGR ratio for homogeneous charge compression ignition (HCCI) operation varied from 30 percent to 45 percent, depending on the operating condition. Three methods were investigated as possible ways to reduce pressure rise rates during LTC operation. The only feasible method was the multiple injection strategy which provided dramatically reduced pressure rise rates across all EGR levels and injection timings.
Author: Markus Bertsch
Publisher: Logos Verlag Berlin GmbH
ISBN: 3832544038
Category : Technology & Engineering
Languages : en
Pages : 170
Get Book Here
Book Description
This thesis discusses experimental investigations to reduce particle number emissions from gasoline engines with direct injection. Measures on a single cylinder research engine with combined usage of a particle number measurement system, a particle size distribution measurement system as well as optical diagnostics and thermodynamic analysis enable an in-depth assessment of particle formation and oxidation. Therefore, numerous optical diagnostic techniques for spray visualisation (Mie-scattering, High-Speed PIV) and soot detection (High-Speed-Imaging, Fiber optical diagnostics) are deployed. Two injectors with different hydraulic flows but identical spray-targeting are characterised and compared by measurements in a pressurised chamber. The operation at higher engine load and low engine speed is in the focus of the experimental work at the engine test bench. Thereby, the low flow velocities in the combustion chamber, caused by the low engine speed, as well as the large amount of fuel injected are major challenges for the mixture formation process. A substantial part of the thesis thus focusses on the detailed analysis of the mixture formation process, which is consisting of fuel injection, interaction of the in-cylinder charge motion with the fuel injected and the fuel properties. Measures for the optimisation of the mixture formation process and the minimisation of the particle number emissions are analysed and evaluated. The charge motion is manipulated by the impression of a directed flow, the variation of the valve timings and valve open curve. The injection process is influenced by a reduction of the hydraulic flow of the injector and an increase of the injection pressure up to 50 MPa. The investigations show fundamental effects and potentials of different variation parameters concerning their emissions reduction potential at the exemplary operation at high engine load. Due to the simultaneous analysis of the in-cylinder charge motion and a thermodynamic analysis, the results can be transferred to different engines.
Author: Sens, Marc
Publisher: Universitätsverlag der TU Berlin
ISBN: 3798327688
Category : Technology & Engineering
Languages : en
Pages : 386
Get Book Here
Book Description
As the combustion engine looks set to remain the dominant energy conversion unit in vehicle powertrains in the medium term, either in combination with electrical components or on its own, attention will need to be paid to continue improving its efficiency in the future. The high development depth of today's combustion engines means that it is becoming increasingly difficult to achieve significant efficiency improvements by simple means. On the search for these improvements, the focus has shifted to inner-engine processes, for instance charge cycles including the charging system, the mixture formation including injection, combustion and kinematic conversion of the energy within the fuel. Our 2nd conference 'Engine processes' aims to offer all developers a platform to discuss the latest technological developments in the field of inner-engine process control, and encourage new paths to be taken. We believe that the program for this conference is a sound foundation for this endeavour. Da der Verbrennungsmotor auch mittelfristig die dominierende Energiewandlungseinheit im Antriebsstrang von Kraftfahrzeugen sein wird, entweder im Verbund mit elektrischen Komponenten oder aber als alleiniger Antrieb, muss der Verbesserung von dessen Wirkungsgrad auch in Zukunft erhebliche Aufmerksamkeit zu Teil werden. Aufgrund der hohen Entwicklungstiefe, die heutige Verbrennungsmotoren aufweisen, wird es immer schwerer, deutliche Wirkungsgradverbesserungen auf einfachem Weg zu erreichen. Auf der Suche nach diesen Verbesserungen rücken die innermotorischen Prozesse immer mehr in den Fokus, hierzu zählen der Ladungswechsel inkl. Aufladesystem, die Gemischbildung inkl. Einspritzung, die Verbrennung sowie die kinematische Wandlung der im Kraftstoff gebundenen Energie. Unsere 2. Tagung „Motorische Prozesse“ soll nun allen Entwicklern als Austauschforum zu neuesten technologischen Entwicklungen auf dem Gebiet der innermotorischen Prozessführung dienen und dazu anregen neue Wege zu beschreiten. Wir sind überzeugt, mit dem vorliegenden Tagungs-Programm hierzu einen sehr guten Beitrag leisten zu können.
Author: Paul Medwell
Publisher: MDPI
ISBN: 3039285106
Category : Technology & Engineering
Languages : en
Pages : 336
Get Book Here
Book Description
The role that combustion plays in the world’s energy systems will continue to evolve with the changes in technological demands. For example, the challenges that we face today are more focused on the conservation of energy and addressing environmental concerns, which together necessitate cleaner and more efficient combustion processes using a range of fuel sources. This book includes contributions to highlight the recent progress in theory and experiments, development, and demonstration of technologies and systems involving combustion processes, for the production, storage, use, and conservation of energy.
