Climate change has become a discussion topic of exponentially increasing urgency and importance amoung world leaders of all disciplines. These changes are brought about by the emission of so-called Greenhouse gases from various human activities. The primary cause of CO2 emissions is the burning of the Earth’s supply of nonrenewable natural fossil fuels like coal, oil and natural gas. The world first agreed on the prevention of “dangerous” climatic changes at the Earth Summit in 1992. The Kyoto Protocol of 1997 was the first step toward protection of the atmosphere and prescribes restrictions on emission pollutants. Since then the vehicle gas emissions are being controlled by means of different gas emissions norms, like the European Union Norm in Europe. The automotive manufacturers and suppliers are collectively working on reducing overall vehicle emissions. They are focusing on several different emission limiting possibilities, for example improved engine design, special fuel development and exhaust gas treatment systems. The exhaust gas treatment process requires continuous controlling and management of the exhaust gas emissions while driving a vehicle. Certain factors such as high emission temperatures have a negative influence on the life span of these systems. Their functionality and durability is also known to be reduced by the presence of chemical poisoning species like sulphur, phosphorus, zinc and calcium. The chemical poisoning species are produced during combustion of fuel and engine oil. They are therefore contained in the exhaust emissions and can poison the catalyst when passing over it. Phosphorous poisoning is particularly problematic and should be reduced considerably. This study involves the investigation of the phosphorous poisoning process and aims to provide clarity regarding the influences of different fuel and oil compositions on the severity of the process. Engine oil and biodiesel are two major sources of phosphorous poisoning. The phosphorus contained in biodiesel fuel is a natural component and can be minimized during the refining procedure. In contrast to others studies, the biodiesel fuel used during this project was SME (Soya Methyl Ester) with a 20% biodiesel content. This choice of fuel was made because of the increasingly important role that this type of biodiesel is playing in the European market and the future tendency to increase the percentage of biodiesel in the mixture with standard diesel fuel. The phosphorus contained in engine oil is a necessary additive to retain the antioxidant and anti-wear properties of the oil. This study examined the poisoning influences from the most commonly used phosphorus containing oil additive, Zinc Dithiophosphates (ZDDP), as well as a Zn-free, phosphorus containing anti-wear oil additive. This formulation provides information about the phosphorus poisoning process as caused by the engine oil in the absence of Zn in the oil additives. The results show how the phosphorus content in biodiesel fuel affects the functionality of the exhaust gas treatment systems and the importance of reducing the permitted content of phosphorus contained in the fuel. Reducing the phosphorus content in the fuel will conserve the functionality of the exhaust gas treatment systems during their operational life and thereby protect the environmental from emission pollutants. It also provides insight into the differences in the poisoning processes when the phosphorus deposited on the catalyst comes from biodiesel fuel and when it comes from the engine oil. Finally the results also illustrate the influence of different phosphorous forms contained in engine oil additives on the catalyst poisoning process. This information could be used for the development of new oil additive formulations.

Orientador: Robson Pederiva / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecânica / Made available in DSpace on 2018-08-22T04:43:06Z (GMT). No. of bitstreams: 1 Tomoyose_Rodrigo_M.pdf: 5460677 bytes, checksum: 829aa7966e143d1d5dfc1a5e6120dd5c (MD5) Previous issue date: 2013 / Resumo: Motores de ciclo Diesel são máquinas formadas por diversos sistemas mecânicos. Dentre esses sistemas há o de acionamento de válvulas, responsável pelo controle de entrada e saída dos gases na câmara de combustão do motor. Para realizar o projeto de um motor, é essencial prever corretamente o funcionamento dinâmico de seu sistema mecânico. Em engenharia utiliza-se para esse fim uma ferramenta matemática, a análise dinâmica. O uso de equações não lineares na análise dinâmica permite desenvolver modelos matemáticos que representem o contato das válvulas com suas sedes de assentamento, o efeito da pressão residual na abertura da válvula ou o funcionamento da válvula de retenção dentro do tucho hidráulico. O trabalho nesta dissertação envolve o desenvolvimento de um modelo matemático que represente o sistema de acionamento de válvulas de um motor Diesel já em produção. Esse modelo poderá ser utilizado para modificação ou melhoria do motor, ou mesmo como base de conhecimento para futuros projetos / Abstract: Diesel engines are machines formed by various mechanical systems, including the valvetrain. This system is responsible for controlling the entry and exit of gases in the combustion chamber of the engine. Able to correctly predict the dynamic operation of the system is essential to design an engine. Dynamic analysis is a mathematical tool used by engineers to be able to predict the dynamic behavior of mechanical systems. The use of nonlinear equations in the dynamic analysis allows developing mathematical models which represent the contact of valve with its seat, the effect of residual pressure in opening the valve or the operation of the check valve within the hydraulic tappet. The work in this dissertation involves developing a mathematical model that represents the valvetrain of a diesel engine already in production. This model can be used to modify or improve the engine, or as a base of knowledge for future projects / Mestrado / Mestre em Engenharia Mecânica

published_or_final_version / Environmental Management / Master / Master of Science in Environmental Management

South Africa is coming under increasing pressure to conform to the rest of the world in terms of emissions regulations. The pressure is caused by a number of factors: international organisations requiring local companies to adhere to environmental conservation policies, evidence from within South Africa that efforts are being made to reduce environmental pollution in line with other countries and keeping abreast of the latest technologies that have been incorporated into vehicles to reduce emissions. In light of these problems associated with emiSSions, a study was initiated by the Department of Transport and the School of Bioresources Engineering and Environmental Hydrology at the University of Natal to investigate and develop a method of predicting emissions from a diesel engine. The main objective of this research was to incorporate this model into SimTrans in order to estimate emissions generated from a vehicle while it is travelling along specific routes in South Africa. SimTrans is a mechanistically based model, developed at the School, that simulates a vehicle travelling along a route, requiring input for the road profile and vehicle and engine specifications. After a preliminary investigation it was decided to use a neural network to predict emissions, as it provides accurate results and is more suitable for a quantitative analysis which is what was required for this study. The emissions that were predicted were NOx (Nitric oxide-NO and Nitric dioxide-N02), CO (carbon monoxide), HC (unbumt hydrocarbons) and particulates. The neural netWork was trained on emissions data obtained from an ADE 447Ti engine. These neural networks were then integrated into the existing SimTrans. Apart from the neural network, an algorithm to consider the effect of ambient conditions on the output of the engine was also included in the model. A sensitivity analysis was carried out using the model to prioritise the factors affecting emissions. Finally using the data for the ADE 447Ti engine, a trip with a Mercedes Benz 2644S-24 was simulated using different scenarios over the routes from Durban to Johannesburg and Cape Town to Johannesburg in South Africa to quantify the emissions that were generated. / Thesis (M.Sc.)-University of Natal, Pietermaritzburg, 2002.

published_or_final_version / Environmental Management / Master / Master of Science in Environmental Management

published_or_final_version / Environmental Management / Master / Master of Science in Environmental Management

published_or_final_version / Transport Policy and Planning / Master / Master of Arts in Transport Policy and Planning

CNPq / Esta dissertação descreve a fabricação, aplicação e os resultados de um sensor de fibra ótica baseada em redes de Bragg regeneradas para a medição de elevadas temperaturas dos gases de exaustão em uma turbina de motor diesel de locomotiva. É proposto um encapsulamento para a FBG com peças em aço inoxidável o qual foi fixado na superfície da turbina. O sensor foi posto a prova sendo submetido em testes em campo variando a potência do motor. Em laboratório foi feita a comparação do sensor ótico com um sensor convencional termopar. Foi possível demonstrar que os valores de temperatura medidos pelos sensores, tanto o sensor a fibra ótica quanto o convencional, seguem a mesma tendência da potência gerada pelo motor e, dessa forma, foi demonstrado a eficiência do funcionamento dos sensores mostrando a medição de temperaturas na turbina. / This paper describes the fabrication, implementation and results of a fiber optic sensor based on Bragg gratings regenerated for measurement of high temperatures of the exhaust gases in a turbine diesel engine locomotive. The proposed sensor with an encapsulation with stainless steel parts which is laid down on the surface of the turbine. The sensor has been challenged undergoing field tests at varying engine power. In the laboratory the optical sensor was compared with a conventional thermocouple sensor. It was possible to demonstrate that the temperature values measured by the sensors, both the optical fiber sensor as the conventional follow the same trend of the power generated by the engine and thus demonstrated the efficiency of the operation of sensors measuring temperatures showing in turbine.

CNPq / Esta dissertação descreve a fabricação, aplicação e os resultados de um sensor de fibra ótica baseada em redes de Bragg regeneradas para a medição de elevadas temperaturas dos gases de exaustão em uma turbina de motor diesel de locomotiva. É proposto um encapsulamento para a FBG com peças em aço inoxidável o qual foi fixado na superfície da turbina. O sensor foi posto a prova sendo submetido em testes em campo variando a potência do motor. Em laboratório foi feita a comparação do sensor ótico com um sensor convencional termopar. Foi possível demonstrar que os valores de temperatura medidos pelos sensores, tanto o sensor a fibra ótica quanto o convencional, seguem a mesma tendência da potência gerada pelo motor e, dessa forma, foi demonstrado a eficiência do funcionamento dos sensores mostrando a medição de temperaturas na turbina. / This paper describes the fabrication, implementation and results of a fiber optic sensor based on Bragg gratings regenerated for measurement of high temperatures of the exhaust gases in a turbine diesel engine locomotive. The proposed sensor with an encapsulation with stainless steel parts which is laid down on the surface of the turbine. The sensor has been challenged undergoing field tests at varying engine power. In the laboratory the optical sensor was compared with a conventional thermocouple sensor. It was possible to demonstrate that the temperature values measured by the sensors, both the optical fiber sensor as the conventional follow the same trend of the power generated by the engine and thus demonstrated the efficiency of the operation of sensors measuring temperatures showing in turbine.

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