Orientador: Alberto Adade Filho / Dissertação (mestrado profissional) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecânica / Made available in DSpace on 2018-08-18T17:00:41Z (GMT). No. of bitstreams: 1 Torrigo_Eduardo_M.pdf: 4407726 bytes, checksum: 787c00ebb1a9971b6c1cf1d6b78d7180 (MD5) Previous issue date: 2011 / Resumo: Tendo em vista a melhora da qualidade do ar, são impostos limites de emissões de poluentes aos motores diesel, obrigando a busca de soluções capazes de reduzir essas emissões. O motor movido a diesel tem como emissão crítica de poluentes os óxidos de nitrogênio e a emissão de material particulado. Toda a química de formação de poluentes está interligada ao processo de combustão, que é diretamente influenciado pelas concentrações de reagentes admitidos no cilindro. A recirculação controlada de gases de escape para a admissão é uma técnica de redução de emissões de óxidos de nitrogênio comumente aplicada ao motor diesel. Motores instalados em veículos estão sujeitos a variações de regime de operação devido à dinâmica veicular, como por exemplo acelerações ou troca de marchas, que produzem alterações na pressão e no fluxo de gases modificando a proporção da mistura de ar limpo e recirculante admitida no cilindro do motor. O sistema de controle dos gases, portanto, é elemento importante no controle das emissões de poluentes. O objeto deste estudo é o projeto e análise de configurações de controle aplicadas ao sistema de ar de um motor diesel. Foram escolhidos os controladores PID descentralizado, atualmente utilizado na indústria, e o regulador linear quadrático com integrador. Para aumentar a representatividade do estudo, é identificado um conjunto de modelos dinâmicos entrada-saída do sistema de ar de um motor diesel para uso no projeto e na simulação dos sistemas de controle. Por intermédio de uma mesma abordagem algorítmica de projeto e utilizando uma função custo de controle ótimo, projetos dessas diferentes alternativas de controle são efetuados e o desempenho dos controladores e suas características são comparados. Os resultados indicam que a configuração multivariável reduz interferências no controle devido ao acoplamento entre as variáveis e também o tempo necessário à acomodação do sistema de ar, mas tem implicações práticas a serem consideradas. Essas características de resposta e desempenho têm impacto na emissão de poluentes, como elaborado no trabalho. Os aspectos práticos de implementação e de confiabilidade também são discutidos / Abstract: Diesel engine technology has been driven by stringent regulation. To fulfill this demand emission control systems are constantly improving The diesel-powered engines are major pollutant sources of nitrogen oxides and particulate matter. All the chemistry of pollutants formation is linked to the combustion, which is directly influenced by concentrations of reagents admitted to the cylinder. The controlled recirculation of exhaust gases to intake chamber is a commonly applied technique to reduce nitrogen oxides emissions of the diesel engines. Engines installed in vehicles are subject to variations in operation due to the vehicle dynamics, such as accelerations or gear shifting, that produce changes in pressures and gases flow, affecting the clean air and recirculated gas mixture proportion admitted to the engine cylinder. The control of the gases therefore plays an important role in pollutant emissions reduction. The goal of this study is the design and analysis of decentralized and multivariable control systems applied to the air management of a diesel engine. To enhance the study representativeness, it is identified a set of dynamic models of the air system of a diesel engine to use in design and of control simulation. The optimal control condition is determined by cost functions reduction. Two different control structure and tuning alternatives are studied and the controller performance and their characteristics are compared. The results indicate that the multivariable proposal (LQR controller with integral action) reduces interferences in the control due to the coupling between variables, it also reduces the settling time of all controlled variables, however the implementation aspects must be evaluated more deeply. The impacts on emissions caused by controller response characteristics and performance are discussed in the work. Reliability and implementation aspects are also discussed / Mestrado / Eletrônica / Mestre em Engenharia Automobilistica

In an effort to reduce harmful pollutants emitted by medium and heavy duty diesel engines, stringent emission regulations have been imposed by the Environmental Protection Agency (EPA) and the California Air Resources Board (CARB). Effective aftertreatment thermal management is critical for controlling tail pipe outlevels of NOx and soot, while improved fuel efficiency is also necessary to meet greenhouse gas emissions standards and customer expectations. Engine manufacturers have developed and implemented several engine and non-engine based techniques for emission reduction, a few examples being: exhaust gas recirculation (EGR), use of delayed in-cylinder injections, exhaust throttling, electric heaters and hydrocarbon dosers. This work elaborates the use of variable valve actuation strategies for improved aftertreatment system (ATS) thermal management of a modern medium-duty diesel engine while presenting opportunities for simplification of engine air handling architecture.<div><br></div><div>Experimental results at curb idle demonstrate that exhaust valve profile modulation enables effective ATS warm-up without requiring exhaust manifold pressure (EMP) control. Early exhaust valve opening with internal exhaust gas recirculation (EEVO+iEGR) resulted in 8% lower fuel consumption and reduction in engine out emissions. Late exhaust valve opening with internal EGR in the absence of EMP control was able to reach exhaust temperature of 287^◦C, without a penalty in fuel consumption or emissions compared to conventional thermal management. LEVO combined with EMP control could reach turbine outlet temperature of nearly 460^◦C at curb idle.<br></div><div><br></div><div>LEVO was studied at higher speeds and loads to assess thermal management benefits of LEVO in the absence of EMP control, with an observation that LEVO can maintain desirable thermal management performance up to certain speed/load conditions, and reduction in exhaust flow rate is observed at higher loads due to the inability of LEVO to compensate for loss of boost associated with absence of EMP control.<br></div><div><br></div><div>Cylinder deactivation (CDA) combined with additional valvetrain flexibility results in low emission, fuel-efficient solutions to maintain temperatures of a warmed-up ATS. Late intake valve closing, internal EGR and early exhaust valve opening were studied with both three cylinder and two cylinder operation. Some of these strategies showed additional benefits such as ability to use earlier injections, elimination of external EGR and operation in the absence of exhaust manifold pressure control. Three cylinder operation with LIVC and iEGR is capable of reaching exhaust temperatures in excess of 230^◦C with atleast 9% lower fuel consumption than three cylinder operation without VVA. Three cylinder operation with early exhaust valve opening resulted in exhaust temperature of nearly 340^◦C, suitable for extended idling operation. Two cylinder operation with and without the use of valve train flexibility also resulted in turbine outlet temperature relevant for extended idling (and low load operation), while reducing fuel consumption by 40% compared to the conventional thermal management strategy.<br></div><div><br></div><div>A study comparing the relative merits of internal EGR via reinduction and negative valve overlap (NVO) is presented in order to assess trade-offs between fuel efficient stay-warm operation and engine out emissions. This study develops an understanding of the optimal valve profiles for achieving reinduction/NVO and presents VVA strategies that are not cylinder deactivation based for fuel efficient stay-warm operation. Internal EGR via reinduction is demonstrated to be a more fuel efficient strategy for ATS stay-warm. An analysis of in-cylinder content shows that NOx emissions are more strongly affected by in-cylinder O2 content than by method of internal EGR.<br></div>

The present Master thesis entitled "Engineering Design and Optimization of Injector Holder" deals with the design of clamping holder, whose function is to ensure the exact position of injector system Common Rail. The shape of the injector holder is designed in the modelling program, both with respect to the installation space of internal combustion engine and also the method of manufacture. The proposed geometry is then subjected to stress analysis in the program using FEM. The final design phase is to optimize the geometry of the injector holder using the same method with the aim to reduce the weight of the component.

The aim of this thesis is design crankshaft for four-cylinder diesel engine with cylinder deactivation. Further, to perform stress analysis of designed crankshaft with considering torsional vibration.

This master thesis, concentrated on crank train mechanism of diesel V6 engines with special focus on design and construction of crankshaft, is divided in two main phases. First phase is concept, which contains brief introduction of diesel V-engines construction, parameters of chosen engine unit, especially crank train mechanism, design of crankshaft and 1D analysis of torsional vibrations. Second phase is layout, this phase deals with MBS 3D analysis with flexible FEM models of crankshaft and engine block. These outputs are used for fatigue analysis of crankshaft.

This works applies the idea of adjustment an engine-generator, so it is possible to connect an engine-generator, or other type of a generator, to the electricity. Consequently, the machine can transform the power supply without an outage. This work concerns the complex approach, provides the descriptions of particular parts, sensors and active components of a motor-generator and includes the explanation of their function. Further research is focused on designing and drawing a plan with a choice of a control unit for the whole system. Finally, the work deals with the complex implementation and testing the machine in real operation.

This master thesis summarizes the basic knowledge in the field of turbocharging of internal combustion piston engines. It also focuses on the analysis of some properties of multistage turbocharging, especially for diesel engines. Using analytical relationships, a model in the form of a web application has been created, which describes the cooperation of a turbocharger or turbochargers with an internal combustion engine. With the help of this model, some two-stage supercharging options for the selected engine have been then proposed.

This diploma thesis with a view to „common rail system for 4-cylinder CI-engine“ deals with the application of modern injection system „common rail“ to already existing compression-ignition tractor engine. The diploma thesis treats of the most necessary adjustments related with the replacement of injection systems which was solved in the way of the minimum adjustments. This kind of solution deals with an economic aspect of the problem. The reconstruction contains the engineering design of development of high pressure components and the suitability of their placing on engine.The primary adjustment of the application of system „common rail“ for existing tractor engine confirmed the possibility of this reconstruction.

The purpose of this thesis is design of in-line a five-cylinder diesel engine arrangement with given main parameters, power train design, balancing centrifugal and inertia moments and calculation of torsion vibrations. The proposed engine must be based on four-cylinder diesel Zetor engine.

his diploma work themed: Five-cylinder in-line Diesel engine with balancing unit is dealing with analysis of balancing possible alternatives of arranging crankshaft, analysis of arranging counterweight, concept of balancing shaft, engineering design of crank-shaft, calculation of frequency, computational control of crank-shaft in light of torsional oscillations and proposal of dynamic pendulum damper.