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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Influence des propriétés physico-chimiques des hydrocarbures sur l'injection et la combustion Diesel / Influence of physico-chemical properties of the fuels on Diesel injection and combustion processes

Dernotte, Jérémie 19 June 2012 (has links)
Dans un contexte de réduction des émissions de polluants et de gaz à effet de serre, mais aussi d’enjeux économiques liés aux ressources en pétrole brut, la nécessité de se diversifier énergétiquement a imposé l’apparition et l’utilisation dans des quantités sans cesse croissantes de carburants de substitution. Ces carburants provenant de nombreuses sources primaires, produits à partir de diverses techniques, possèdent des propriétés physico-chimiques différentes. Les effets de chaque propriété sur le comportement du moteur Diesel (émissions, rendement, etc.) ne sont pas encore compris de manière détaillée. La présente thèse porte sur une étude expérimentale de l’influence des propriétés physico-chimiques des carburants sur les processus physiques se déroulant dans la chambre de combustion pour des applications sur moteurs Diesel. L’originalité de l’approche réside par la définition d’une matrice de carburants (20 carburants au total) dont les propriétés varient de manière indépendante. De plus, les différentes étapes de l’injection Diesel ont été considérées. On s’intéresse par la mise en oeuvre de huit techniques de mesures avancées, à la caractérisation de l’hydraulique dans les orifices de l’injecteur, de la structure du spray, de son atomisation, sa vaporisation et enfin la combustion du mélange résultant. Ces expériences ont été conduites dans des cellules adaptées et sur moteur à accès optiques permettant de reproduire des conditions de fonctionnement représentatives. L’analyse porte essentiellement sur la phase quasi-stationnaire de l’injection pendant laquelle les résultats expérimentaux sont corrélés à des modèles basés sur la physique issus de la littérature et de nouvelles corrélations empiriques sont proposées. / In a context of pollutant emission and green house gas reduction, but also economic issues related to crude oil ressources, the necessity for energy diversification has imposed the emergence and the use in growing quantities of substitute fuels. These fuels derived from numerous feedstocks, produced by several manufacturing processes, have different physico-chemical properties. The effects of each individual property on the Diesel engine behavior (emissions, efficiency, etc) are not well fully understood yet. The present thesis focuses on an experimental study about the influence of physico-chemical properties of the fuels on the processes occuring in the combustion chamber for Diesel engine application. The originality of the approach concerns the definition of a fuel matrix (a total of 20 fuels) for which properties are independently varied. Moreover every stages of the Diesel injection are considered. The interest focuses by the setting of eight advance measurement technics on the caracterization of the flow into the injector orifices, the spray structure and atomization, the spray vaporization and finally the Diesel combustion. Experiments were conducted in dedicated vessels and in an optical access engine allowing to reproduce representive operating conditions. The analysis mainly focuses on the quasi-stationnary phase of the injection event and experimental results are scaled to physic-based models and new empirical correlation are proposed.
2

Analysis of Fuel Performance and Exhaust Emissions of Ultra-low Sulphur Diesel Blending with Biofuels

Chen, Kung-Fu 17 February 2005 (has links)
This study investigated the fuel properties, engine performances, and emissions of two biodiesels and diesel. The fuels examined were D100 (ultra-low sulfur diesel), B20 (20% palm biodiesel +80% ultra-low sulfur diesel) and B100 (palm biodiesel). The fuel properties analysis results showed that the benefits of biodiesel were high cetane value, extremely low sulfur and aromatic contents, and good lubricity. While the defects of biodiesel were high pour point. The particulates emitted from the burning of D100, B100, B20 were mainly fine particulates, also known as young aerosols. Particles smaller than 2.5 µm easily enter the trachea and bronchus via the upper respiratory tract, finally deposit on the alveolus, which could cause severe injury to human health. The emission of soluble organic fraction (SOF) from diesel engine using D100, B100 and B20 were 23.2%, 19.9% and 20.2%, respectively. The SOF of D100 is slightly higher than B100 and B20. It suggested that adding biodiesel into diesel can decrease SOF and thus reduce the potential danger to human health. The original total PAHs concentration of tail gas emitted from engines using D100, B100 and B20 were 241, 50.6 and 98.8 µg/m3, respectively. Adding 20% biodiesel into D100 could reduce 59.0% of PAHs emission. Moreover, the original total BaPeq concentration of tail gas emitted from diesel engines using D100, B100 and B20 were 0.714, 0.509 and 0.570 µg/m3, respectively. Adding 20% biodiesel into D100 could also reduce 20.2% of total BaPeq emission. Hence, adding biodiesel into diesel can effectively reduce the emission of PAHs and the potential danger to human health. The emission factors of carbonyl compounds from diesel engines using D100, B100 and B20 were 395, 1,170 and 326 mg/BHP-hr, respectively. carbonyl compounds of B100 were obviously higher than D100 and B20. The results indicated that using pure palm biodiesel in diesel engine can increased the emission of carbonyl compounds. However, adding 20% biodiesel into D100 can effectively reduce 17.5% of carbonyl compounds emission. Keyword: ultra-low sulfur diesel, palm biodiesel, fuel properties¡BThe emission of soluble organic fraction (SOF)¡BPAHs¡Bcarbonyl compounds¡C
3

Criteria for solid recovered fuels as a substitute for fossil fuels – a review

Beckmann, Michael, Pohl, Martin, Bernhardt, Daniel, Gebauer, Kathrin 05 June 2019 (has links)
The waste treatment, particularly the thermal treatment of waste has changed fundamentally in the last 20 years, i.e. from facilities solely dedicated to the thermal treatment of waste to facilities, which in addition to that ensure the safe plant operation and fulfill very ambitious criteria regarding emission reduction, resource recovery and energy efficiency as well. Therefore this contributes to the economic use of raw materials and due to the energy recovered from waste also to the energy provision. The development described had the consequence that waste and solid recovered fuels (SRF) has to be evaluated based on fuel criteria as well. Fossil fuels – coal, crude oil, natural gas etc. have been extensively investigated due to their application in plants for energy conversion and also due to their use in the primary industry. Thereby depending on the respective processes, criteria on fuel technical properties can be derived. The methods for engineering analysis of regular fuels (fossil fuels) can be transferred only partially to SRF. For this reason methods are being developed or adapted to current analytical methods for the characterization of SRF. In this paper the possibilities of the energetic utilization of SRF and the characterization of SRF before and during the energetic utilization will be discussed.
4

ALTERNATIVE DIESELS FROM PLANT OILS AND THEIR EVALUATION OF FUEL PROPERTIES / 植物油からの軽油代替燃料と燃料特性評価

Sugami, Yuitsu 23 March 2017 (has links)
京都大学 / 0048 / 新制・課程博士 / 博士(エネルギー科学) / 甲第20478号 / エネ博第347号 / 新制||エネ||69(附属図書館) / 京都大学大学院エネルギー科学研究科エネルギー社会・環境科学専攻 / (主査)教授 坂 志朗, 教授 塩路 昌宏, 准教授 河本 晴雄 / 学位規則第4条第1項該当 / Doctor of Energy Science / Kyoto University / DGAM
5

L'Influence des propriétés physiques et chimiques du biodiesel, Diesel et de leur mélange sur l’injection et le spray / The influence of physical properties of biodiesel, Diesel and their blended fuels on injection and spray

Tinprabath, Padipan 23 April 2015 (has links)
Le biodiesel est un carburant très intéressant car du fait de son caractère renouvelable il augmente la sécurité énergétique et est plus respectueux de l'environnement. De plus il a un indice de cétane plus élevé et une plus faible teneur en soufre et en aromatique que le Diesel pur. Les principaux inconvénients de biodiesel sont sa viscosité élevée, sa faible teneur en énergie, un point trouble et le point d'écoulement plus élevé, une émission d'oxyde d'azote (NOx) plus élevée lors de sa combustion et un coût élevé. Cependant, de nombreux pays peuvent produire leur propre biodiesel et assurer des mélanges d’une teneur entre 2 et 20% de biodiesel avec du carburant diesel. Les nouvelles normes Euro VI impliquent des problèmes liés au démarrage à froid. Pour approfondir notre compréhension de ces mélanges, il est nécessaire de tester un plus large éventail de carburants de 10 à 50% de biodiesel jusqu’à -8°C pour pallier le manque d’information dans la littérature. La présente thèse porte sur une étude expérimentale sur l'influence des propriétés physiques et chimiques des mélanges de carburants Biodiesel/Diesel sur l'injection : taux et répartition des sprays dans des conditions de non évaporation. L'originalité de l'approche concerne la définition d'une matrice de carburant (un total de neuf combustibles) dont les propriétés sont modifiées via le pourcentage de biodiesel ou la température. En outre tous les stades de l'injection diesel sont considérés. Des expériences ont été menées en enceinte contrôlée en température. L'analyse se concentre principalement sur la phase quasi-stationnaire de l'événement d'injection et les résultats expérimentaux sont disponibles pour calibrer des modèles physiques et de nouvelles corrélations empiriques sont proposées. / Biodiesel is a very interesting fuel because it is renewable, thus increasing energy security, it is environmentally friendly, and it has a higher cetane number and a lower sulfur and aromatic content than pure Diesel. The main disadvantages of biodiesel are its higher viscosity, lower energy content, higher cloud point and pour point, higher nitrogen oxide (NOx) emissions, lower power and high cost. However, many countries can produce their own biodiesel and blends with diesel fuel of 2–20%. The new Euro VI standards involve problems related to cold-start. To further our understanding of these mixtures, it is necessary to test a larger range of fuels with a biodiesel fraction of 10 to 50%, and under cold temperatures, no information is available in the literature, however, on the injection rate and spray penetration of Diesel–Biodiesel blends in cold conditions. The present thesis focuses on an experimental study of the Influence of physical and chemical properties of biodiesel, Diesel and their blended fuels on injection and spray for Diesel engine application. The originality of the approach concerns the definition of a fuel matrix (a total of 9 fuels) for which properties are varied by varying the percentage of biodiesel and the temperature. Moreover all the stages of Diesel injection are considered. Experiments were conducted in dedicated temperature-controlled vessels. The analysis focuses mainly on the quasi-stationary phase of the injection event and experimental results are scaled to physics-based models and new empirical correlations are proposed.
6

ANALYTICAL AND EXPERIMENTAL INVESTIGATION OF MULTI-COMPONENT SURROGATE DIESEL FUELS

SZYMKOWICZ, PATRICK 03 November 2017 (has links)
Diesel fuel is composed of a complex mixture of hundreds of hydrocarbons that vary globally depending on crude oil sources, refining processes, legislative requirements and other factors. In order to simplify the study of this fuel, researchers create surrogate fuels with a much simpler composition, in an attempt to mimic and control the physical and chemical properties of Diesel fuel. The first surrogates were single-component fuels such as n-heptane and n-dodecane. Recent advancements have provided researchers the ability to develop multi-component surrogate fuels and apply them to both analytical and experimental studies. The systematic application of precisely controlled surrogate fuels promises to further enhance our understanding of Diesel combustion, efficiency, emissions and particulates and provide tools for investigating new and alternative engine combustion systems. This thesis employed analytical and experimental methods to develop, validate and study a library of multi-component surrogate Diesel fuels. The first step was to design a surrogate fuel to precisely match the physical and chemical properties of a full-range petroleum Diesel fuel with 50 cetane number and a typical threshold soot index value of 31. The next step was to create a Surrogate Fuel Library with 18 fuels that independently varied two key fuel properties: cetane number and threshold soot index. Within the fuel library cetane number ranged from 35 to 60 at three threshold soot index levels of 17, 31 and 48 (low, mid-range and high). Extensive ASTM fuel property tests showed that good agreement with important physical and chemical properties of petroleum Diesel fuel such as density, viscosity, heating value and distillation curve. An experimental investigation was conducted to evaluate the combustion, emissions, soot and exhaust particles from the petroleum Diesel fuel and the matching surrogate fuel. A fully-instrumented single-cylinder Diesel engine was operated with combustion strategies including Premixed Charge Compression Ignition (PCCI), Low-Temperature Combustion (LTC) and Conventional Diesel Combustion (CDC). For combustion, the ignition delay, low-temperature (first stage) and high temperature (second stage) heat-release matched very well. Gaseous emissions, soot and exhaust particles maintained good agreement as exhaust gas recirculation and combustion phasing were varied. This thesis demonstrated that fully representative Diesel surrogate fuels could be tailored with the proper blending of the following hydrocarbon components: n-hexadecane, 2,2,4,4,6,8,8-heptamethylnonane, decahydronaphthalene and 1-methylnaphthalene. It was also established that the volumetric blending fractions of these four components could be varied to independently control the fuel cetane number and threshold soot index while retaining the combustion, physical and chemical properties of full-range petroleum Diesel fuel. The Surrogate Fuel Library provided by this thesis supplies Diesel engine researchers and designers the ability to analytically and experimentally vary fuel cetane number and threshold soot index. This new capability to independently vary two key fuel properties provides a means to further enhance the understanding of Diesel combustion and design future combustion systems that improve efficiency and emissions. / El combustible diésel está compuesto por cientos de hidrocarburos cuya presencia y proporción varía dependiendo del origen del crudo, del proceso de refinado, de los requerimientos legislativos, y de muchos otros factores. Para evitar las dificultades que produce esta variabilidad y complejidad en su composición, en los estudios sistemáticos, los investigadores suelen trabajar con combustibles de sustitución, mucho más sencillos, pero que reproducen las propiedades químicas y físicas del gasóleo. Los primeros combustibles de sustitución estuvieron formados por un solo componente, como el n-heptano y el n-dodecano. Recientemente se han desarrollado combustibles de sustitución multi-componentes, que se aplican tanto a estudios experimentales como de modelado. La aplicación sistemática de combustibles de sustitución controlados con precisión es una vía prometedora para mejorar la comprensión de la combustión Diesel, su eficiencia, y sus emisiones y proporciona herramientas para la investigación de sistemas de combustión nuevos y alternativos. En esta tesis se han empleado métodos experimentales y de cálculo para desarrollar, estudiar y validar una librería de combustibles de sustitución multi-componentes. El primer combustible de sustitución se diseñó para reproducir con precisión las propiedades físicas y químicas de un gasóleo con número de cetano 50 y un índice de hollín umbral (TSI) de 31.El siguiente paso fue crear una biblioteca de combustibles de sustitución con 18 combustibles que pueden modificar independientemente dos propiedades clave del combustible: índice de cetano y TSI. En la biblioteca de combustibles el número de cetano osciló entre 35 y 60 con tres niveles de TSI iguales a 17, 31 y 48 (bajo, medio y alto rango). Los ensayos según la normativa ASTM demostraron una buena coincidencia con las propiedades del gasóleo como densidad, viscosidad, poder calorífico y curvas de destilación. Para comprobar la validez de la librería, se realizó un estudio experimental comparativo sobre el proceso de combustión, las emisiones gaseosas, hollín y partículas de un gasóleo y de su combustible de sustitución ajustado. El estudio se realizó con un motor monocilíndrico Diesel completamente instrumentado y operando con estrategias de combustión en premezcla parcial (PPCI) y de baja temperatura (LTC), además de la combustión Diesel convencional (CDC). Los parámetros de la combustión como el retraso al encendido y la liberación de calor tanto de baja como de alta temperatura se aproximaron muy bien. Las emisiones de gases, hollín y partículas también fueron similares al variar el nivel de EGR y la fase de la combustión. La tesis demuestra que se pueden encontrar combustibles de sustitución perfectamente representativos de un gasóleo corriente, en base a mezclas apropiadas de n-hexadecano, 2,2,4,4,6,8,8-heptamethylnonano, decahidronaftaleno y 1-metilnaftaleno. Asimismo, se concluye que variando la proporción de estos cuatro componentes se puede controlar independientemente el número de cetano y el índice de hollín umbral, a la vez que se mantienen las propiedades físico-químicas y de combustión del gasóleo. La librería de combustibles de sustitución definida en esta tesis es una herramienta a disposición de los investigadores para profundizar en el conocimiento de la combustión diésel y avanzar en el diseño de sistemas futuros de combustión con mejor rendimiento y menores emisiones. / El combustible Diesel està compost per centenars d'hidrocarburs, la presència i proporció dels quals varia depenent de l'origen del cru, del procés de refinat, dels requeriments legislatius, i de molts altres factors. Per a evitar les dificultats que produeix aquesta variabilitat i complexitat en la seua composició, en els estudis sistemàtics, els investigadors solen treballar amb combustibles de substitució, molt més senzills, però que reprodueixen les propietats químiques i físiques del gasoil. Els primers combustibles de substitució van estar formats per un sol component, com el n-heptà i el n-dodecà. Recentment s'han desenvolupat combustibles de substitució multi-components, que s'apliquen tant a estudis experimentals com de modelatge. L'aplicació sistemàtica de combustibles de substitució controlats amb precisió és una via prometedora per a millorar la comprensió de la combustió Dièsel, la seua eficiència, i les seues emissions i proporciona eines per a la recerca de sistemes de combustió nous i alternatius. En aquesta tesi s'han emprat mètodes experimentals i de càlcul per a desenvolupar, estudiar i validar una llibreria de combustibles de substitució multi-components. El primer combustible de substitució es va dissenyar per a reproduir amb precisió les propietats físiques i químiques d'un gasoil amb índex de cetà 50 i un índex de sutge límit (TSI) de 31. El següent pas va ser crear una biblioteca de combustibles de substitució amb 18 combustibles que poden modificar independentment dues propietats clau del combustible: índex de cetà i TSI. En la biblioteca de combustibles l'índex de cetá va oscil·lar entre 35 i 60 amb tres nivells de TSI iguals a 17, 31 i 48 (baix, mitjà i alt rang). Els assajos segons la normativa ASTM van demostrar una bona coincidència amb les propietats del gasoil com a densitat, viscositat, poder calorífic i corbes de destil·lació. Per a comprovar la validesa de la llibreria, es va realitzar un estudi experimental comparatiu sobre el procés de combustió, les emissions gasoses, sutge i partícules d'un gasoil i del seu combustible de substitució ajustat. L'estudi es va realitzar amb un motor monocilíndric Dièsel completament instrumentat i operant amb estratègies de combustió en premescla parcial (PPCI) i de baixa temperatura (LTC), a més de la combustió Dièsel convencional (CDC). Els paràmetres de la combustió com el retard a l'encès i l'alliberament de calor tant de baixa com d'alta temperatura es van aproximar molt bé. Les emissions de gasos, sutge i partícules també van ser similars en variar el nivell d'EGR i la fase de la combustió. La tesi demostra que es poden trobar combustibles de substitució perfectament representatius d'un gasoil corrent, sobre la base de mescles apropiades de n-hexadecà, 2,2,4,4,6,8,8-heptamethylnonà, decahidronaftalé i 1-metilnaftaleno. Així mateix, es conclou que variant la proporció d'aquests quatre components es pot controlar independentment l'índex de cetà i l'índex de sutge límit, alhora que es mantenen les propietats físic-químiques i de combustió del gasoil. La llibreria de combustibles de substitució definida en aquesta tesi és una eina a la disposició dels investigadors per a aprofundir en el coneixement de la combustió Diesel i avançar en el disseny de sistemes futurs de combustió amb millor rendiment i menors emissions. / Szymkowicz, P. (2017). ANALYTICAL AND EXPERIMENTAL INVESTIGATION OF MULTI-COMPONENT SURROGATE DIESEL FUELS [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/90406 / TESIS
7

Effect of Changes in Flow Geometry, Rotation and High Heat Flux on Fluid Dynamics, Heat Transfer and Oxidation/Deposition of Jet Fuels

Jiang, Hua 12 May 2011 (has links)
No description available.

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