Dissertations / Theses on the topic 'Fuel injection timing angle'

Дисертація на здобуття наукового ступеня кандидата технічних наук зі спеціальності 05.05.03 – двигуни та енергетичні установки. – Національний технічний університет "Харківський політехнічний інститут". – Харків, 2016. Дисертаційна робота присвячена дослідженню впливу регульованого температурного стану поршнів дизеля різного призначення на його техніко-економічні показники. Розроблено та реалізовано методику оцінки якості дизеля при регулюванні інтенсивності масляного охолодження поршнів та керуванні моментом початку впорскування палива в камеру згоряння, а також при врахуванні моделі експлуатації енергетичної установки. Проведено експериментальні дослідження впливу температурного стану поршнів з низькотеплопровідним покриттям поверхні камери згоряння транспортного дизеля, а також зміни кута випередження впорскування палива на показники токсичності відпрацьованих газів, паливної економічності та температурний стан деталей камери згоряння. В результаті виконаного оптимізаційного дослідження запропоновано характеристичні карти керування масляним охолодженням поршнів та моментом початку впорскування палива для комплексного покращення техніко-економічних показників дизеля. Оцінено ефективність впровадження запропонованих заходів в автомобільних та тракторних дизелях та стаціонарних дизельгенераторах. Запропоновано методику врахування температурного стану найбільш теплонавантажених зон поршня в загальній методиці оцінки якості дизеля. Проведені розрахункові дослідження дозволили визначити ефективність регулювання температурного стану поршнів на ресурсну міцність його камери згоряння.
Thesis for the science degree of the Candidate of technical sciences by speciality 05.05.03 – engines and power plants. – National Technical University "Kharkоv polytechnic institute", Kharkоv, 2016. Dissertation is devoted to research of complex influence of pistons temperature state regulation on the diesel engine technical and economic performance. In the dissertation work a method of estimating the quality of the diesel engine when regulating of the pistons temperature state, which takes into account indicators of exhaust gases toxicity and ICE fuel efficiency in each mode of the power plant operation is proposed. Experimental study of the effect of temperature condition of pistons with low conductive coating combustion chamber surface and changes the fuel injection timing angle on the exhaust gases toxicity, fuel economy and thermal condition of combustion chamber parts is done. As a result of the optimization research the characteristic cards control of pistons oilcooling and the fuel injection start for complex diesel engine technical and economic indicators improvement are proposed, the effectiveness of their use in automobile and tractor diesel engines and stationary diesel generators are estimated. The method of accounting of the most heat-loaded piston zones temperature state in general procedure of diesel quality assessment is proposed. Conducted estimated researches have allowed to define the effectiveness of pistons temperature state regulation on the combustion chamber resource strength.

Дисертація на здобуття наукового ступеня кандидата технічних наук зі спеціальності 05.05.03 – двигуни та енергетичні установки. – Національний технічний університет "Харківський політехнічний інститут". – Харків, 2016. Дисертаційна робота присвячена дослідженню впливу регульованого температурного стану поршнів дизеля різного призначення на його техніко-економічні показники. Розроблено та реалізовано методику оцінки якості дизеля при регулюванні інтенсивності масляного охолодження поршнів та керуванні моментом початку впорскування палива в камеру згоряння, а також при врахуванні моделі експлуатації енергетичної установки. Проведено експериментальні дослідження впливу температурного стану поршнів з низькотеплопровідним покриттям поверхні камери згоряння транспортного дизеля, а також зміни кута випередження впорскування палива на показники токсичності відпрацьованих газів, паливної економічності та температурний стан деталей камери згоряння. В результаті виконаного оптимізаційного дослідження запропоновано характеристичні карти керування масляним охолодженням поршнів та моментом початку впорскування палива для комплексного покращення техніко-економічних показників дизеля. Оцінено ефективність впровадження запропонованих заходів в автомобільних та тракторних дизелях та стаціонарних дизельгенераторах. Запропоновано методику врахування температурного стану найбільш теплонавантажених зон поршня в загальній методиці оцінки якості дизеля. Проведені розрахункові дослідження дозволили визначити ефективність регулювання температурного стану поршнів на ресурсну міцність його камери згоряння.
Thesis for the science degree of the Candidate of technical sciences by speciality 05.05.03 – engines and power plants. – National Technical University "Kharkоv polytechnic institute", Kharkоv, 2016. Dissertation is devoted to research of complex influence of pistons temperature state regulation on the diesel engine technical and economic performance. In the dissertation work a method of estimating the quality of the diesel engine when regulating of the pistons temperature state, which takes into account indicators of exhaust gases toxicity and ICE fuel efficiency in each mode of the power plant operation is proposed. Experimental study of the effect of temperature condition of pistons with low conductive coating combustion chamber surface and changes the fuel injection timing angle on the exhaust gases toxicity, fuel economy and thermal condition of combustion chamber parts is done. As a result of the optimization research the characteristic cards control of pistons oilcooling and the fuel injection start for complex diesel engine technical and economic indicators improvement are proposed, the effectiveness of their use in automobile and tractor diesel engines and stationary diesel generators are estimated. The method of accounting of the most heat-loaded piston zones temperature state in general procedure of diesel quality assessment is proposed. Conducted estimated researches have allowed to define the effectiveness of pistons temperature state regulation on the combustion chamber resource strength.

Thesis (Ph. D.)--Ohio State University, 2004.
Title from first page of PDF file. Document formatted into pages; contains xxiv, 266 p. : ill. (some col.). Advisor: Yann G. Guezennec, Dept. of Mechanical Engineering. Includes bibliographical references (p. 259-266).

Rising global energy demands have led to an increase in demand for clean, sustainable energy. A leading technology for reducing greenhouse gas (GHG) emission for existing coal-power infrastructure is gasification, which has sparked an interest in reactor modelling for design and performance analysis. Reduced order models (ROMs) have seen an increase in popularity for entrained flow gasifiers, as they offer a low-computational alternative to conventional computational fluid dynamic (CFD) modelling while maintaining the integrity of important operational parameters, such as carbon conversion and syngas yield. However, ROMs require more physical parameter inputs than are normally required for CFD modelling, such as the geometry of the gas-solid jet (specifically the jet half-angle). Experiments were conducted to understand the relation between the required input parameters for ROMs, such as fuel flow rate, transport gas flow rate, and jet half-angle, and develop useful correlations for ROM systems. A new configuration for pneumatic conveying was developed and tested at the pilot-scale system at NRCan CanmetENERGY. It was used to study the pneumatic conveying of pulverized fuels, specifically the influence of operating parameters such as pressure drop and gas flow rates on the fuel flow rate, and the geometry of the gas-solid fuel jet (notably the jet half-angle) injected into the gasifier. The mean fuel flow rate of pulverized fuels was shown to increase with increasing pressure drop and with decreasing gas flow rates in the fuel transfer line. The jet half-angle was shown to increase as the solid loading ratio in the jet core was decreased. Finally, the relative fuel flow variability was observed to be significantly influenced by the design of the pneumatic conveying system, with the fluctuations increasing with increasing pressure drop and with decreasing gas flow rate, similar to the mean flow rate.

[EN] This research work presents the study of a low pressure EGR loop influence on a SI gasoline turbocharged direct injection engine in steady and transient testing conditions, with an optimization process of the original engine calibration in order to minimize the engine fuel consumption when cooled EGR is introduced in steady testing conditions. The cooled EGR strategy was also evaluated operating in synergy with other fuel consumption reduction strategies, such as: lean burn, multi-injection, higher coolant temperature and in-cylinder induced swirl motion. To fulfill the main objectives of this research work, firstly, a methodical process was followed, where a global methodology was first developed in order to obtain high accuracy engine tests, based on the experimental tools chosen that could comply with the requirements of the testing conditions, and the appropriate theoretical tools and procedure to post-process the tests performed. Secondly, a specific methodology was developed for each stage of the study and testing conditions, taking into account optimization processes or parametric tests in order to study the effect of a single parameter on engine's outputs or optimize an engine parameter in order to minimize the engine fuel consumption. As a first stage of the study, a basic analysis of the impact of cooled EGR on the engine combustion, performance, air management and exhaust emissions is presented. Afterwards, an optimization of the combustion phasing in order to minimize the fuel consumption was performed, and therefore the potential of cooled EGR in order to reduce the engine fuel consumption was observed for low load, part load and full load engine conditions, for two different engine speeds. In addition, a study in transient conditions of the engine operating with cooled EGR was performed. NEDC cycles were performed with different EGR valve openings and therefore a comparison of different cooled EGR rates influence on the engine performance, air management and accumulated exhaust emissions was presented. The second stage, consisted in a methodology developed to optimize the VVT setting and injection timing, for part load engine conditions, in order to maximize the cooled EGR potential to reduce engine fuel consumption. After this optimization, a synergy analysis of the optimum engine condition operating with cooled EGR and three other engine fuel consumption reduction strategies was performed. These strategies were tested to investigate and evaluate the potential of increasing the cooled EGR operational range to further decrease the engine fuel consumption. Furthermore, a basic study of the potential to reduce the engine fuel consumption and impact on combustion, air management and exhaust emissions of a lean burn strategy, in part load engine conditions, was presented as introduction of the final study of the cooled EGR strategy operating in synergy with the lean burn strategy in order to investigate the potential to control the exhaust emissions and reduce the engine fuel consumption.
[ES] El objetivo de este trabajo de investigación es estudiar la influencia de un lazo de baja presión de EGR en las prestaciones de un motor de gasolina de encendido provocado turbosobrealimentado e inyección directa, en condiciones de ensayos estacionarios y transitorios, con un proceso de optimización de la calibración original del motor para minimizar el consumo de combustible del motor. La estrategia de "cooled EGR" fue también evaluada operando en sinergia con otras estrategias usadas para reducir el consumo de combustible del motor, entre ellas: mezcla pobre, múltiples inyecciones, operación a alta temperatura del fluido refrigerante del motor y movimiento de "swirl" inducido en el cilindro. Para cumplir con los objetivos mencionados, se siguió un proceso metódico donde previamente se desarrolló una metodología global para obtener resultados de indudable calidad, basados en el uso de herramientas experimentales que cumplieran con los requerimientos de las condiciones de ensayo, y las apropiadas herramientas teóricas y procedimiento para post-procesar los ensayos realizados. En segundo lugar, se desarrolló una metodología específica para cada etapa del estudio, teniendo en cuenta los procesos de optimización o estudios paramétricos que se pudieran realizar. Como primera etapa, se presenta un estudio básico del impacto del "cooled EGR" en la combustión, prestaciones, renovación de la carga y emisiones contaminantes del motor. Seguidamente, se procedió a la optimización del centrado de la combustión con la finalidad de minimizar el consumo de combustible del motor y poder analizar el potencial del "cooled EGR" como estrategia de reducción de consumo de combustible. El estudio presentado se realizó para baja, media y alta carga del motor con dos diferentes regímenes de giro del motor. Adicionalmente, se llevó a cabo un estudio del motor operando en condiciones transitorias con "cooled EGR". Se realizaron una serie de ensayos usando el ciclo NEDC como base y se probaron diferentes estrategias sencillas de control de la apertura de la válvula de EGR para analizar la influencia del "cooled EGR" en condiciones transitorias. La segunda etapa consiste en el desarrollo de una metodología para optimizar los parámetros del diagrama de distribución (VVT) y el inicio de inyección, para cargas medias del motor, con la finalidad de maximizar el potencial de reducción de consumo de combustible de la estrategia "cooled EGR". Una vez realizada la optimización, se llevó a cabo un estudio usando la configuración óptima encontrada, operando en sinergia con otras tres estrategias usadas para reducir el consumo de combustible del motor. Estas estrategias fueron evaluadas con la finalidad de incrementar el rango de operación de la estrategia "cooled EGR" para lograr reducir aún más el consumo de combustible del motor. Adicionalmente, se llevó a cabo un estudio básico sobre la influencia de operar con mezcla pobre en la combustión, prestaciones, renovación de la carga y emisiones contaminantes del motor, como introducción al último estudio llevado a cabo sobre la posibilidad de usar la estrategia de mezcla pobre en conjunto con la estrategia de "cooled EGR", con la finalidad de analizar el potencial de controlar las emisiones contaminantes y reducir el consumo de combustible del motor al mismo tiempo.
[CAT] L'objectiu d'este treball d'investigació és estudiar la influència d'un llaç de baixa pressió d'EGR en les prestacions d'un motor de gasolina d'encesa provocat turbosobrealimentat i injecció directa, en condicions d'assajos estacionaris i transitoris, amb un procés d'optimització del calibratge original del motor per a minimitzar el consum de combustible del motor. L'estratègia de "cooled EGR" va ser també avaluada operand en sinergia amb altres estratègies usades per a reduir el consum de combustible del motor, entre elles: mescla pobra, múltiples injeccions, operació a alta temperatura del fluid refrigerant del motor i moviment de `"swirl" induït en el cilindre. Per a complir amb els objectius mencionats, es va seguir un procés metòdic on prèviament es va desenrotllar una metodologia global per a obtindre resultats d'indubtable qualitat, basats en l'ús de ferramentes experimentals que compliren amb els requeriments de les condicions d'assaig, i les apropiades ferramentes teòriques i procediment per a post- processar els assajos realitzats. En segon lloc, es va desenrotllar una metodologia específica per a cada etapa de l'estudi, tenint en compte els processos d'optimització o estudis paramètrics que es pogueren realitzar. Com a primera etapa, es presenta un estudi bàsic de l'impacte del "cooled EGR" en la combustió, prestacions, renovació de la càrrega i emissions contaminants del motor. A continuació, es va procedir a l'optimització del centrat de la combustió amb la finalitat de minimitzar el consum de combustible del motor i poder analitzar el potencial del "cooled EGR" com a estratègia de reducció de consum de combustible. L'estudi presentat es va realitzar per a baixa, mitja i alta càrrega del motor amb dos diferents règims de gir del motor. Addicionalment, es va dur a terme un estudi del motor operand en condicions transitòries amb "cooled EGR". Es van realitzar una sèrie d'assajos usant el cicle NEDC com a base i es van provar diferents estratègies senzilles de control de l'obertura de la vàlvula d'EGR per a analitzar la influència del "cooled EGR" en condicions transitòries. La segona etapa consistix en el desenrotllament d'una metodologia per a optimitzar els paràmetres del diagrama de distribució (VVT) i l'inici d'injecció, per a càrregues mitges del motor, amb la finalitat de maximitzar el potencial de reducció de consum de combustible de l'estratègia "cooled EGR". Una vegada realitzada l'optimització, es va dur a terme un estudi usant la configuració òptima trobada, operant en sinergia amb altres tres estratègies usades per a reduir el consum de combustible del motor. Estes estratègies van ser avaluades amb la finalitat d'incrementar el rang d'operació de l'estratègia "cooled EGR" per a aconseguir reduir encara més el consum de combustible del motor. Addicionalment, es va dur a terme un estudi bàsic sobre la influència d'operar amb mescla pobra en la combustió, prestacions, renovació de la càrrega i emissions contaminants del motor, com a introducció a l'últim estudi dut a terme sobre la possibilitat d'usar l'estratègia de mescla pobra en conjunt amb l'estratègia de "cooled EGR", amb la finalitat d'analitzar el potencial de controlar les emissions contaminants i reduir el consum de combustible del motor al mateix temps.
Rivas Perea, ME. (2016). Assessment of fuel consumption reduction strategies on a gasoline turbocharged direct injection engine with a cooled EGR system [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/68497
TESIS

This study has been performed at Powertrain Engineering Sweden AB (PES), a fully owned subsidiary of Volvo Cars Group, which is constantly working to develop and improve internal combustion engines. As part of this work, durability tests are performed to analyse the impact of wear on the engines. At present, there is a strong focus on visual inspections after the engines have undergone durability tests. PES wants to develop a method where collected data from these tests can be used to explain how the phenomenon of knocking and the control of lambda changes over time. The study analyses one specific durability test and investigates the methodology of data analysis by using the open-source software platform Sympathy for Data, with an add-on developed by Volvo Cars Group, for data management, visualisation and analysis. To execute the analysis, engine parameters that affect these systems as well as parameters suitable to use as response variables are identified through literature studies of internal combustion engine fundamentalsas well as internal material, and knowledge acquired at the company. The result is presented in the form of an analysis generated by the node for partial least squares regression (PLSR) which is pre-programmed in Sympathy for Data as well as the images and graphs obtained as output. For knock, the signal for the final ignition angle was found to be suitable to use as the response variable in the PLSR. A suitable response variable for lambda was more difficult to identify, this is why both signals for the measured lambda and lambda adaptation are analysed. Studies of the internal material and knowledge highlighted the fact that several engine subsystems are highly dependent on each other and that even deeper research would be necessary to fully understand the process and identify the primary cause for the variations observed in the generated models. However, partial least squares regression was performed using parameters derived from literature reviews as input (predictors) in order produce regression models to explain the variance in sought response. Well-fitting models could be created with a varying number of latent variables needed for the different responses. The output obtained from the PLSR enables further studies of the specific cases as well as the methodology itself, hence, increase the use of data analysis with the help of the software used in the department for durability testing at PES.
Denna studie är utförd hos Powertrain Engineering Sweden AB (PES), vilka är ett helägt dotterbolag till Volvo Cars Group, som arbetar med att ta fram och förbättra förbränningsmotorer. En del i detta arbete är att genomföra långtidstest för att analysera hur motorernas egenskaper ändras vid förslitning över tid. I nuläget ligger stort fokus på visuella inspektioner efter att motorerna genomgått långtidstester. PES önskar utveckla en metod där redan insamlad data som registrerats i dessa tester kan förklara hur fenomenet knack och regleringen för lambda förändras över tid. Studien är genomförd i form av en fallstudie av ett specifikt långtidstest där den öppna programvaran Sympathy for Data, tillsammans med det av Volvo Cars Group utvecklade tillägget, används för datahantering, visualisering och analys. Studien undersöker också metodiken för dataanalys med nämnd programvara. För att genomföra detta identifieras motorparametrar som påverkar de undersökta systemen samt parametrar som lämpar sig att användas som responsvariabler i en regressionsmodell. Dessa parametrar togs fram genom litteraturstudier om de fundamentala delarna i en förbränningsmotor samt från företaget förvärvad intern kunskap kring systemen. Resultatet presenteras i form av en analys genomförd med den, i Sympathy for Data, förprogrammerade noden för partial least squares regression(PLSR) samt de bilder och grafer som erhålls. För knack visade det sig att den slutliga tändningsvinkeln var lämplig att använda som respons i PLSR-modellen. En lämplig responsvariabel för lambda var mer svåridentifierad, detta förklarar varför signalerna för uppmätt lambda och lambda adaption analyseras. Inläsning av internt material och grundläggande information om förbränningsmotorer visade att delsystem i ottomotorn är beroende och påverkas av varandra vilket innebär att mer ingående studier i dessa delsystem är nödvändigt för att förstå hela processen och hitta grundorsakerna till variationerna som påvisas för responssignalerna. Vidare utfördes PLSR med de parametrar som härletts från litteraturstudier som indatasignaler (prediktorer) för att skapa en regressionsmodell som förklarar variansen i sökta responssignaler. Beroende av responssignal krävdes varierande antal latenta variabler för att uppnå en tillräckligt precis modell. Resultatet från PLSR möjliggör vidare forskning inom området och metoden som använts och har på så sätt möjliggjort för fortsatt utveckling. Detta i sin tur kan öka användandet av dataanalys med hjälp av den programvara som används vid avdelningen för långtidstest hos PES.

碩士
中華科技大學
機電光工程研究所在職專班
106
The purpose of this study is to understand the impact of fuel additives on engine output horsepower through experiments to increase understanding of the knowledge of gasoline fuel additives. Evaluate the efficacy of the additive by using a programmable computer system to change the specific speed and adjust the ignition timing angle. The program observes the experimental results through five parameter settings. The experimental parameters include: engine speed (5000 rpm, 6000 rpm, 7000 rpm), fuel type (gasoline, gasoline added 1% biodiesel and gasoline added 2% biodiesel), ignition timing angle (BTDC 26°~ 34°, BTDC 27°~35°, BTDC 28°~36°, BTDC 29°~37°), rolling resistance coefficient 0.01 and air-fuel ratio AFR 13.3, to discuss the effect of the above operation on engine output horsepower and fuel consumption. . In this study, commercially available 92 unleaded gasoline (G100) was used in a single-cylinder four-stroke machine jet engine, and 1% and 2% bio-diesel were added to unleaded gasoline as experimental fuels (GB1 and GB2). Under the operating conditions of engine speed N=5000, 6000, 7000 rpm and air-fuel ratio control under AFR=13.3, the influence of ignition timing angle on engine output horsepower and fuel consumption is analyzed by experimental results, using biodiesel as Gasoline additives, with the help of a programmable computer system (aRacer RC1 Super), adjust the ignition timing angle within a specific speed range, and fail to achieve the hypothetical goal of increasing horsepower and reducing fuel consumption.

Societal concerns on combustion-based fuel consumption are ever-increasing. With respect to internal combustion engines, this translates to a need to increase brake fuel conversion efficiency (BFCE). Diesel engines are a relatively efficient internal combustion engine to consider for numerous applications, but associated actions to mitigate certain exhaust emissions have generally deteriorated engine efficiency. Conventionally, diesel engine emission control has centered on in-cylinder techniques. Although these continue to hold promise, the industry trend is presently favoring the use of after-treatment devices which create new opportunities to improve the diesel engine's brake fuel conversion efficiency. This study focuses on injection timing effects on the combustion processes, engine efficiency, and the engine system's responses. The engine in the study is a medium duty diesel engine (capable of meeting US EPA Tier III off road emission standards) equipped with common rail direct fuel injection, variable geometry turbo charging, and interfaced with a custom built engine controller. The study found that injection timing greatly affected BFCE by changing the combustion phasing. BFCE would increase up to a maximum then begin to decrease as phasing became less favorable. Combustion phasing would change from being mostly mixing controlled combustion to premixed combustion as injection timing would advance allowing more time for fuel to mix during the ignition delay. Combustion phasing, in turn, would influence many other engine parameters. As injection timing is advanced, in-cylinder temperatures and pressures amplify, and intake and exhaust manifold pressures deteriorate. Rate of heat release and rate of heat transfer increase when injection timing is advanced. Turbocharger speed falls with the advancing injection timing. Torque, however, rose to a maximum then fell off again even though engine speed and fueling rate were held constant between different injection timings. Interestingly, the coefficient of heat transfer changes from a two peak curve to a smooth one peak curve as the injection timing is advanced further. The major conclusion of the study is that injection advance both positively and negatively influences the diesel engine's response which contributes to the brake fuel conversion efficiency.

碩士
國立成功大學
機械工程學系
102
Effects of inlet channel angle on the gas feeding dynamics in pulsed detonation cycle in a micro pulsed detonation engine were investigated in the study. Stoichiometric of ethylene/oxygen were used and high-speed cinematography were applied to observe the flame propagation in mixing section and inlet manifolds upstream of the ignition spot. Laser shadowgraph was also utilized to analyze the shock propagations in the manifolds. It can be found that both of 60° and 90° were typical detonation wave, and a low-speed detonation mode in 30° case. By using a gas chromatography(GC) to measure the mixing status in different angle cases. The equivalent ratio decreased with inlet angle increase. It can be seen that with the smaller inlet angle, there were an intense shock wave propagating back into the inlet manifolds. With 90° inlet angle, the shock wave could only propagate until the cross section, and the expansion resulted in the dissipation of the shock. A dynamic pressure sensor was installed on the oxygen feeding channel to quantify the pressure evolutions in the inlet manifold. The results showed that the shut-off duration for the 30° to 90° inlet was about 306, 219 and 299 us respectively. And reduce to 281, 266 and 270 us by increasing supply pressure. Comparison of single shot and continuous operating of 70 Hz, there were the slowest reaction wave velocity in the inlet section. A cavity design has been apply in the manifold. It can be seen that the shock wave in oxygen manifold were not obvious in cavity case. And the value of peak pressure were 0.45 MPa in original design but there were only 0.12 MPa in cavity case.

碩士
國立中正大學
機械工程學系暨研究所
99
This paper to tires in the cracking furnace, low temperature below 350 ℃ in the cracking gases generated by the condensation of the resulting tire pyrolysis oil, in two different proportions of commercial diesel (D100) mix, its called T10, T20 bio-oil, diesel engines do real vehicle dynamometer test, known single-cylinder fuel injection quantity and injection angle from m_f1 crank angle θ_A to θ_D, atomized oil droplets to establish θ_A to θ_B mode, when the starting point of spontaneous combustion occurred θ_B the establishment of atomized droplets burning mode, theoretical calculations of the engine combustion chamber temperature, obtained by the state role in relation to the piston of the pressure to get the role of the crank shaft of the torque and speed worthy of the theoretical calculations with the instructions horsepower, analysis results that change the initial injection point θ_A, can effectively reduce the pollutants NOx and HC, the output power in, θ_A changes can help to add the tire pyrolysis oil for diesel engine oil of better output horsepower.

碩士
國立雲林科技大學
機械工程系碩士班
100
This research applies a modified GDI engine (re-assemble from a 500C.C. gasoline EFI engine). A common-rail 100 bar injection system is equipped with a injector placed on the top of the cylinder head (perpendicular to the piston surface). The engine runs at 3000, 4000, and 5000 rpm, the throttle opens at 20%, 30%, and 40% TPS. The fuel is injected at two stage with the injection mass ratio 4：6, 5：5, and 6：4 respectively. The engine performance and exhaust emissions are studied. The GDI engine has two stage injection, by increasing the first injection amount, the cylinder charge has better homogeneous charge mixing before the second inject onset. Results show the increased first injection ratio can promote the engine torque by 5%~20%. The CO emission is reduced by 5%~15% and the HC emission is reduced by 15%~40%. When the comparison is made between the optimized two stage injections and the single stage injection (semi-port fuel injection), the volumetric efficiency is slightly increased by 1%~2%. The engine torque under high engine load and engine speed case is not able to be increased by running the GDI mode since the spray plug is placed on the side of the combustion chamber. The CO emission is increased by 10%~40%, the HC emission is increased by 5%~20%, and the NO emission is reduced by 10~30% due to instantaneous charge temperature. However when this two-stage injection mode is compared to the singe stage (quasi-EFI injection) mode, the side placed spark plug causes the un-effective flame propagation inside the combustion chamber, thus, the engine performance is deteriorated, and the emissions are increased.

碩士
雲林科技大學
機械工程系碩士班
96
This study is performed on a KYMCO SJ25BA 125c.c. 4-strokes air-cooled EFI engine. The spray phenomena inside the intake manifold are acquired by using high speed flash-assisted images taking technology. The spray velocity, penetration, spray angle, and the spray droplet diameter are measured. Two spray angle nozzle adaptor and two spray fuel injection pressure are performed on a handmade 2-D intake manifold channel and the real engine to study these parameters on the engine performance and the exhaust emissions. The study shows the fuel spray has a helical liquid jet pattern. The helical liquid jet then breakup into smaller jet and the droplets near the liquid jet also breakup into smaller ones. The spray velocity appears as a decaying helical shape. By increasing the spray angle 10o the spray impinged on the intake valve stem and breaks up into smaller droplets. By decreasing the spray angle 5o the spray impinged on the intake valve skirt and left wetted fuel film on the intake manifold wall. The spray is carried on in a open space to observe its characteristics. The engine is then controlled under various engine speeds, various injection pressures, and various spray angles with fixed engine throttle position and air fuel ratio. The engine performance and the exhaust emissions are then compared to the spray atomization analysis to interpolate these results. Results show that if the injection pressure is increased the NO is reduced and the CO is increased. The engine torque is increased and fuel consumption is saved by 2% if the spray angle is increased. If the fuel injection pressure is also increased the engine torque can be promoted by 16.77% and the fuel consumption rate is saved by 13.66%.

碩士
國立雲林科技大學
機械工程系碩士班
100
This research studies the diesel engine performance and exhaust emissions after the CY190 1000C.C. single cylinder traditional engine is modified to common-rail two-stage HCCI(homogeneous Charge Compression Ignition) mode. The injection pressure is set at 600 bars and the total diesel fuel stoichiometric ratio is set at variable Φd=0.2, 0.3, 0.4, and 0.5. The engine speed is set at variable rpm=1500, 1800, 2100, and 2400. The two stage injection ratio SOI-1st : SOI-2nd is also variable in this study to understand the engine performance and exhaust emissions. The first part of this study fixes the SOI-2nd injection angle at 19°CA BTDC while the SOI-1st injection angle is variable between 10°CA to 170°CA BTDC. The results show the best injection angle is 10°CA BTDC. The second part of this study set the ratio SOI-1st : SOI-2nd at 3:7, 4:6, 5:5, 6:4, and7:3. The results indicate the ratio SOI-1st : SOI-2nd at 3:7 has the best performance. The third part of this study compares the original single stage injection (19°CA BTDC) and the best two-stage injection engine performance and exhaust emissions. This research concludes the two-stage HCCI mode has engine torque slightly increased due the pre-mixing phenomenon provides a quasi-homogeneous fuel-air mixing zone. The ignition delay for traditional engine is shortened but the incomplete combustion occurs at the cylinder surface boundary layer and quenching zone. The engine torque is promoted by 12%~66%, the HC emission is increased by 37%~54%, the CO emission is increased by 64%~175%, and the smoke is also slightly increased by0.8%~4%.

Thesis (M.S.)--University of Wisconsin--Madison, 2001.
Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 208-211).

Yes
Dual-fuel HCCI engines allow a relatively small quantity of diesel fuel to be used to ignite a variety of fuels such as natural gas or methane in HCCI mode. The gaseous fuel is mixed with the incoming air, and diesel fuel is sprayed into the cylinder by direct injection. Mathematical modelling is used to investigate the effects of parameters such as premixed ratio (fuel ratio) and pilot fuel injection timing on combustion of a dual-fuel HCCI engines. A CFD package is used with AVL FIRE software to simulate dual-fuel HCCI combustion in detail. The results establish a suitable range of premixed ratio and liquid fuel injection timing for low levels of NOx, CO and HC emissions along with a reliable and efficient combustion. Dual-fuel HCCI mode can increase NOx emission with lower premixed ratios in comparison to normal HCCI engines, but it is shown that the NOx emission reduces above a certain level of the premixed ratio. Due to the requirement of homogenous mixing of liquid fuel with air, the liquid fuel injection is earlier than for diesel engines. It is shown that, with careful control of parameters, dual-fuel HCCI engines have lower emissions in comparison with conventional engines.

碩士
國立中興大學
機械工程學系所
101
This study is to investigate the performance and emissions of diesel engine operating with butanol/diesel fuel blends, injection timing vatiation and exhaust gas recirculation. Using injection timing variation and exhaust gas recirculation may deteriorate the smoke emission, therefore the diesel particulate filter was used to assess the reduction in smoke. Engine experiments were conducted at steady stateat four conditions, including mode 1(idle), mode 2(100%load,1650rpm), mode 7(25%load,1650rpm), and mode 11(25%load,1950rpm). The results reveal that the maximum torque decreased with the use of the butanol/diesel fuel blends,injection timing retarding, and exhaust gas recirculation. Use of butanol/diesel fuel blends slightly increased BSFC, but BSEC remained the same. Retarding injection timing and use of exhaust gas recirculation caused increase in BSFC and decrease in BTE. It is noted that butanol/diesel fuel blends may decrease the exhaust temperature significantly. However, adjust injection timing and use of exhaust gas recirculation almost have no effect to the exhaust temperature. With the use of butanol/diesel fuel blends, NOX and exhaust opacity decrease with the increase in the percentage of butanol. However, retarding injection timing can lower NOX, but has no effect to opacity. Advancing injection timing can reduce opacity, but increases NOX emission. Using exhaust gas recirculation can diminish NOX effectively, but smoke emission gets worse. In summary, using advancing injection timing or exhaust gas recirculation, as well as the diesel particulate filter, can improve both the emission of NOx and opacity as much as 80% in smoke and 20%~70% in NOx.