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Combustion and Emission Characteristics of Variable Compression Ignition Engine Fueled with Jatropha curcas Ethyl Ester Blends at Different Compression Ratio  [PDF]
Rajneesh Kumar,Anoop Kumar Dixit
Journal of Renewable Energy , 2014, DOI: 10.1155/2014/872923
Abstract: Engine performance and emission characteristics of unmodified biodiesel fueled diesel engines are highly influenced by their ignition and combustion behavior. In this study, emission and combustion characteristics were studied when the engine operated using the different blends (B10, B20, B30, and B40) and normal diesel fuel (B0) as well as when varying the compression ratio from 16.5?:?1 to 17.5?:?1 to 18.5?:?1. The change of compression ratio from 16.5?:?1 to 18.5?:?1 resulted in 27.1%, 27.29%, 26.38%, 28.48%, and 34.68% increase in cylinder pressure for the blends B0, B10, B20, B30, and B40, respectively, at 75% of rated load conditions. Higher peak heat release rate increased by 23.19%, 14.03%, 26.32%, 21.87%, and 25.53% for the blends B0, B10, B20, B30, and B40, respectively, at 75% of rated load conditions, when compression ratio was increased from16.5?:?1 to 18.5?:?1. The delay period decreased by 21.26%, CO emission reduced by 14.28%, and emission increased by 22.84% for B40 blends at 75% of rated load conditions, when compression ratio was increased from 16.5?:?1 to 18.5?:?1. It is concluded that Jatropha oil ester can be used as fuel in diesel engine by blending it with diesel fuel. 1. Introduction The world is presently confronted with the twin crises of fossil fuel depletion and environmental degradation. Indiscriminate extraction and lavish consumption of fossil fuels have led to reduction in underground-based carbon resources. The search for alternative fuels, which promise a harmonious correlation with sustainable development, energy conservation, efficiency, and environmental preservation, has become very important today. Intensive research is going on throughout the globe for a suitable diesel substitute. In this race among different alternatives, vegetable oils have attained primary place as some of their physical, chemical, and combustion related properties are nearly similar to those of diesel fuel. A lot of research work has been carried out to use vegetable oil in its neat form. Since India is net importer of vegetable oils, edible oils cannot be used for substitution of diesel fuel. So, major concentration has been focused on nonedible oils as the fuel alternative to diesel fuel. Many efforts have been made by several researchers to use nonedible oil as an alternative fuel in CI engine. Nonedible oil from the plant seeds is the most promising alternative fuel for CI engine, because it is renewable, environment friendly, nontoxic, biodegradable, also has no sulphur and aromatics, and has favorable heating value and higher cetane
Performance and Emission Characteristics of Diesel Engine Fueled with Ethanol-Diesel Blends in Different Altitude Regions
Jilin Lei,Yuhua Bi,Lizhong Shen
Journal of Biomedicine and Biotechnology , 2011, DOI: 10.1155/2011/417421
Abstract: In order to investigate the effects ethanol-diesel blends and altitude on the performance and emissions of diesel engine, the comparative experiments were carried out on the bench of turbo-charged diesel engine fueled with pure diesel (as prototype) and ethanol-diesel blends (E10, E15, E20 and E30) under different atmospheric pressures (81 kPa, 90 kPa and 100 kPa). The experimental results indicate that the equivalent brake-specific fuel consumption (BSFC) of ethanol-diesel blends are better than that of diesel under different atmospheric pressures and that the equivalent BSFC gets great improvement with the rise of atmospheric pressure when the atmospheric pressure is lower than 90 kPa. At 81 kPa, both HC and CO emissions rise greatly with the increasing engine speeds and loads and addition of ethanol, while at 90 kPa and 100 kPa their effects on HC and CO emissions are slightest. The changes of atmospheric pressure and mix proportion of ethanol have no obvious effect on NOx emissions. Smoke emissions decrease obviously with the increasing percentage of ethanol in blends, especially atmospheric pressure below 90 kPa.
Premixed ignition characteristics of blends of gasoline and diesel-like fuels on a rapid compression machine  [PDF]
Han Dong,Guang Huanyu,Yang Zheng,Lu Xingcai
Thermal Science , 2013, DOI: 10.2298/tsci120114052h
Abstract: Fuel ignition process is of importance in premixed diesel low-temperature combustion strategies because longer ignition delay could provide more fuel and air mixing time. Using blends of gasoline and diesel-like fuels might be a possible way for the ignition delay extension. In this study, a rapid compression machine is employed to investigate the characteristics of premixed ignition processes of blends of n-heptane and commercial gasoline. The proportion of gasoline in blended fuels and the compression ratio in this rapid compression machine are varied to investigate the effects of fuel component and compression ratio on ignition processes. It is found that blended test fuels have two-stage increases in their cylinder pressure traces, indicating that a low temperature heat release process exists before the main combustion stage. Increased gasoline proportion in test fuels reduces peak cylinder pressure and maximum pressure rise rates, while the 1st, 2nd and overall ignition delay are extended. Increased compression ratio elevates the peak cylinder pressure, and shortens the 1st stage, 2nd stage and overall ignition delays. The maximum pressure rising rates are also increased with compression ratio, so when the low gasoline proportion test fuels are used, knock combustion tends to occur at high compression ratio conditions. However, as long as the gasoline proportion increases to a sufficient level, knock combustion is avoided.
Thermodynamic Modeling for Performance Analysis of Compression Ignition Engine Fuelled With Biodiesel and its Blends With Diesel  [PDF]
Prof. Sanjay Patil
International Journal of Recent Technology and Engineering , 2013,
Abstract: In this work, computer simulation framework for compression ignition engine cycle simulation is developed and engine performance is predicted. Double wiebe’s function is used to model the rate of heat release due to combustion to predict heat released during premixed as well as diffusive phase of combustion. Effect of convective heat transfer and variation in specific heat of test fuels are also considered during development of model. Suitable correlations are established between adjustable parameters of wiebe’s function, relative air-fuel ratio and engine operating conditions, such that the simulated heat release profile matches closely with experimental results. The simulation model is used to analyze the performance, combustion and emission characteristics of single cylinder 3.5 kW rated power diesel engine fuelled with Diesel (D0), Palm Oil Methyl Ester (POME) and POME-diesel blends. The model validation is done by comparing the predicted parameters like brake thermal efficiency and in-cylinder pressure with experimental results and are found in closer approximation. The model is also used to predict net heat release rate, exhaust gas temperature, NOx and soot.
Characteristics of ultrafine particle from a compression-ignition engine fueled with low sulfur diesel
Wei Liu,WuGao Zhang,Zhu Lei,XinLing Li,Zhen Huang
Chinese Science Bulletin , 2009, DOI: 10.1007/s11434-009-0304-2
Abstract: Number size distributions (NSDs, 10–487 nm) and composition of nanoparticle emitted from an engine fueled with ordinary diesel (OD) and low sulfur diesel (LSD) fuel were comparatively studied. The results indicate that, compared with the OD, the LSD was found to slightly decrease the mass concentration, and significantly reduce the number concentration of the total particles (10–487 nm), and the reduction of number increased with the speed and load of engine. The NSD for the two fuels showed a similar bimodal structure under all test engine conditions. Under the same engine conditions, the nucleation mode for LSD fuel was significantly lower than that of ordinary diesel. However, the accumulation mode for the two fuels showed little difference. The elements composition of exhaust particles included C, O, Cl, S, Si, Ca, Na, Al and K. The S element was not detected in LSD fuel case. The main component of soluble organic fraction (SOF) of exhaust particles for the two fuels included saturated alkane (C15–C26), ester and polycyclic aromatic hydrocarbons (PAHs). However, PAHs were not found in LSD fuel case.
An Experimental Investigation of Thermal Behavior of Engine Fueled with Diesel and Bio-Diesel Blends B20N and B80N
M.Prabhahar,Dr.S.Sendilvelan,R.Murali Manohar
Indian Streams Research Journal , 2012,
Abstract: In the present experimental research work, used vegetable oil methyl ester (UVOME) is derived through transesterification of used vegetable oil using methanol in the presence of sodium hydroxide (NaOH) catalyst. Experimental investigations have been carried out to examine the combustion characteristics in a direct injection transportation diesel engine running with diesel, biodiesel (UVOME), and its blends with diesel such as B20N and B80N.A careful analysis of the crank angle at which heat release occurs was carried out. The result has shown that biodiesel blends has higher heat release and exhaust gas temperature than diesel.
Vibration signatures of a biodiesel fueled CI engine and effect of engine parameters  [PDF]
S. Jindal
International Journal of Energy and Environment , 2012,
Abstract: With increasing emphasis on use of biodiesel in compression ignition engines, the long term effects are yet to be evaluated. Through many studies, the suitability of biodiesel blends upto 20% are well established and are being adopted by many organizations with recommended use of biodiesel. But in all of these studies the combustion and emission evaluations are the main characteristics which received the attention of researchers and the objectives targeted are good performance and low emissions. The long term effects are difficult to be assessed as it requires long time as well as consistent conditions of operation. A short route is suggested in this study using the vibration signatures of the engine cylinder and head vibrations. The comparison between the vibration signatures of an engine fueled with diesel and biodiesel blends under different compression ratio and injection pressures show significant changes in the vibration patterns and the difference can be used to asses the long term effects. The method is based on fundamental relationship between the engines vibration pattern and the relative characteristics of the combustion process under different operating conditions.
Performance evaluation of diesel engine with oxygenated bio-fuel blends  [PDF]
T. Krishnaswamy,N. Shenbaga
Journal of Engineering and Applied Sciences , 2012,
Abstract: The use of oxygenated bio-fuels like bio diesel and ethanol in combination with diesel is an effective measure to substitute renewable fuels and reduce particulate matter (PM) from in-use diesel vehicles. To study the fuel performance, three oxygenated blend fuel designs containing volumes of 15% ethanol with cetane improver additive, 10% ethanol with 10% bio diesel and 15% ethanol with 20% bio diesel were formed. The physical stability of ethanol diesel blend is studied and phase separation is prevented by adding co solvents like Tetrahydrafuran and bio diesel. To meet stricter emission norms, now diesel engines are fitted with after treatment devices. This paper describes the engine and emission characteristics of the above blend fuels on a 4 cylinder, naturally aspirated light duty diesel engine fitted with diesel oxidation catalyst. The engine test results show that it is feasible to use these blends in diesel engines: the thermal efficiencies of the engine fueled by the blends are comparable with that fueled by diesel, with small increase in fuel consumption, due to the lower heating value of ethanol and bio diesel. The smoke emissions from the engine fueled by the blends are lower than that fueled by diesel owing to the increased oxygen content. The reduction is more at higher loads. The HC and CO emissions are found to be higher at lower loads due to the lower cetane number of ethanol. However, NO emissions depend on load conditions and blend contents.
Computer Simulation of CI Engine for Diesel and Biodiesel Blends
Laukik P. Raut
International Journal of Innovative Technology and Exploring Engineering , 2013,
Abstract: Among the alternative fuels, biodiesel and its blends are considered suitable and the most promising fuel for diesel engine. The properties of biodiesel are found similar to that of diesel. Many researchers have experimentally evaluated the performance characteristics of conventional diesel engines fuelled by biodiesel and its blends. However, experiments require enormous effort, money and time. Hence, a cycle simulation model incorporating a thermodynamic based single zone combustion model is developed to predict the performance of diesel engine. A comprehensive computer code using “C” language was developed for compression ignition (C.I) engine. Combustion characteristics such as cylinder pressure, heat release, heat transfer and performance characteristics such as work done, brake power and brake thermal efficiency (BTE) were analyzed. On the basis of first law of thermodynamics the properties at each degree crank angle was calculated. The simulated combustion and performance characteristics are found satisfactory with the experimental results.
Combustion and emission characteristics of a diesel engine fuelled with jatropha and diesel oil blends  [PDF]
Elango Thangavelu,Senthilkumar Thamilkolundhu
Thermal Science , 2011, DOI: 10.2298/tsci100614088e
Abstract: The depletion of oil resources as well as the stringent environmental regulations has led to the development of alternate energy sources. In this work the combustion, performance and emission characteristics of a single cylinder diesel engine when fuelled with blends of jatropha and diesel oil are evaluated. Experiments were conducted with different blends of jatropha oil and diesel at various loads. The peak pressures of all the blends at full load are slightly lower than the base diesel. There is an increase in the ignition delay with biodiesel because of its high viscosity and density. The results show that the brake thermal efficiency of diesel is higher at all loads followed by blends of jatropha oil and diesel. The maximum brake thermal efficiency and minimum specific fuel consumption were found for blends up to B20. The specific fuel consumption, exhaust gas temperature, smoke opacity and NOx were comparatively higher. However there is an appreciable decrease in HC and CO2 emissions while the decrease in CO emission is marginal. It was observed that the combustion characteristics of the blends of esterified jatropha oil with diesel followed closely with that of the base line diesel.
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