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Technical Paper

Investigation on Premixed Charge Compression Ignition Combustion Control Using Multi Pulse Ultrahigh Pressure Injection

2019-04-02
2019-01-1155
Compression ignition (CI) engines provide higher thermal efficiency compared to other internal combustion engines although large amounts of NOx and soot are produced during combustion. NOx and soot emissions can be reduced by using Premixed Charge Compression Ignition (PCCI) combustion. However, the problems of PCCI combustion include limited operating range, unstable start of combustion and an increase in combustion noise. The multi-pulse ultrahigh pressure injection allows fuel to be injected near TDC, improving mixture formation and enhancing the possibility to extend the operating range of PCCI combustion. The objective of this paper is to control and extend the operating range of PCCI combustion using multi-pulse ultrahigh pressure injection. This has not been studied before. Combustion characteristics were investigated using apparent rate of heat release analysis, heat balance analysis, exhaust emission measurement and soot concentration measurement.
Technical Paper

Characterization of Carbon Fiber and Glass Fiber’s Micro and Nanostructure Using Electron Microscopy, Raman Spectroscopy and XRD Analysis

2019-03-25
2019-01-1441
Nowadays, most manufacturers are looking for the improvement of lightweight parts and other components in the automobile field. Carbon fiber and glass fiber are the most effective materials for their requirement to reduce the weight in vehicles due to their light weight and high tensile strength. The diameter of carbon fiber is 6 μm while glass fiber diameter is 17 μm. The mechanical tensile force of carbon fiber and glass fiber are 430 N and 290 N respectively on fiber alone without matrix. Carbon fibers are gradually smaller in each filament due to tensile force. Approximately 5 mm are elongated for both carbon fiber and glass fiber in tensile test report. In current research, characteristic and tensile force of carbon fiber and glass fiber were investigated by using electron microscopy, Raman spectroscopy and XRD.
Technical Paper

Impact of TiO2 and V2O5 on Sintered Mullite Porous Microstructure and Soot Oxidation Kinetics Using SEM and TGA

2019-03-25
2019-01-1407
The exhaust emissions from diesel combustion are the sources of particulate matter emitted to the atmosphere, which are components of air pollution that implicated in human health such as lung cancer. At present the diesel particulate filter can remove PM from the exhaust gas before emitted to the atmosphere. This research is investigating morphology and structure of acicular mullite to develop the fabrication process filter in order to study particulate matters trapping and oxidation mechanisms. This paper used two main substances to study the structure of diesel particulate filter (DPFs); Aluminum oxide (Al2O3) and Silicon dioxide (SiO2). These are mainly in the conventional DPFs. The variable substances are Titanium dioxide (TiO2) and Vanadium oxide (V2O5), which added to investigate and produce the acicular mullite DPFs structure. The mullite samples were sintered at 1300 oC with holding time of 1 h.
Technical Paper

A Cycle-to-Cycle Variation Extraction Method for Flow Field Analysis in SI IC Engines Based on Turbulence Scales

2019-01-15
2019-01-0042
To adhere to stringent environmental regulations, SI (spark ignition) engines are required to achieve higher thermal efficiency. In recent years, EGR (exhaust gas recirculation) systems and lean-burn operation has been recognized as key technologies. Under such operating conditions, reducing CCV (cycle-to-cycle variation) in combustion is critical to the enhancement of overall engine performance. Flow-field CCV is one of the considerable factors affecting combustion in engines. Conventionally, in research on flow fields in SI engines, the ensemble average is used to separate the measured velocity field into a mean component and a fluctuation component, the latter of which contains a CCV component and a turbulent component. To extract the CCV of the flow field, previous studies employed spatial filter, temporal filter, and POD (proper orthogonal decomposition) methods.
Technical Paper

Impact of Biodiesel on Small CI Engine Combustion Behavior and Particle Emission Characteristic

2017-11-05
2017-32-0094
Diesel engines are high thermal efficiency because of high compression ratio but produce high concentration of particulate matter (PM) because of direct injection fuel diffusion combustion. PM must be removed from the exhaust gas to protect human health. This research describes biodiesel engine performance, efficiency and combustion behavior using combustion pressure analyzer. It was clearly observed that PM emitted from CI engines can be reduced by using renewable bio-oxygenated fuels. The morphology and nanostructure of fossil fuel and biofuel PMs were investigated by using a Scanning electron microscopy (SEM) and Transmission electron microscopy (TEM). The morphology of biodiesel and diesel doesn’t have much different in the viewpoint of particulate matter trapping using DPF micro surface pores. The agglomerated ultrafine particles and primary nanoparticles sizes of diesel and biodiesel engine’s PM are approximately 50-500 nm and 20-50 nm, respectively.
Technical Paper

The Effect of Exhaust Gas Recirculation on Performance and Emission of Ethanol Fumigated Diesel Engine

2017-11-05
2017-32-0101
Primary energy source such as fossil fuel keep decreasing due to various kind of usage. According to less amount of the fossil fuel, human seeks for an alternative fuel source such as alcohol. Alcohol like ethanol can be produced easily from strarchy plant. But using alcohol as blended fuel with diesel fuel doesn't work well because alcohol has low cetane number, lack of lubricity and very low miscibility with diesel fuel. To overcome this, fumigation system or port fuel injection of alcohol seems interesting. Although it requires more complicate system but it can compensate the miscibility issue and alcohol can be used in higher dose to give more energy. Diesel engine produces a lot of emission such as NOx and some other carbon content emission like HC, CO and soot due to they run in lean condition as their characteristic. Modern diesel engines are now coupled with exhaust gas recirculation system to help reduce in main emission like NOx.
Technical Paper

Heat Transfer Analysis in a Diesel Engine Based on a Heat Flux Measurement Using a Rapid Compression and Expansion Machine

2017-11-05
2017-32-0115
To investigate the heat transfer phenomena inside the combustion chamber of a diesel engine, a correlation for the heat transfer coefficient in a combustion chamber of a diesel engine was investigated based on heat flux measured by the authors in the previous study(8) using the rapid compression and expansion machine. In the correlation defined in the present study, thermodynamically estimated two-zone temperatures in the burned zone and the unburned zone are applied. The characteristic velocity given in the correlation is related to the speed of spray flame impinging on the wall during the fuel injection period. After the fuel injection period, the velocity term of the Woschni’s equation is applied. It was shown that the proposed correlation well expresses heat transfer phenomena in diesel engines.
Technical Paper

Effect of Biofuel and Soot on Metal Wear Characteristic Using Electron Microscopy and 3D Image Processing

2017-11-05
2017-32-0095
The soot contamination in used engine oils of diesel engine vehicles was about 1% by weight. The soot and metal wear particle sizes might be in the range of 0-1 µm and 1-25 µm, respectively. The characteristics of soot affecting on metal wear was investigated. Soot particle contamination in diesel engine oil was simulated using carbon black. Micro-nanostructure of soot particles were studied by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and laser diffraction spectroscopy (LDS). The metal wear behavior was studied by means of a Four-Ball tribology test with wear measured. Wear roughness in micro-scale was investigated by high resolution optical microscopy (OM) , 3D rendering optical technique and SEM image processing method. It was found that the ball wear scar diameter increased proportionally to the soot primary particle size. The effect of biodiesel contamination were also increasing in wear scar diameter.
Technical Paper

Characterization of Biodiesel Particle Emission in Trapping and Regeneration Processes on Cordierite Diesel Particulate Filter

2015-11-17
2015-32-0821
As well-known, the diesel engine has the highest thermal efficiency at the same load as compared with internal combustion engine but its disadvantage is particulate matter (PM) emitted to the atmosphere. The studies of this paper were divided into two parts. The first part studied the quantity of PM from the both diesel and biodiesel fuels at 80% load (2400 rpm) by the trapping process on diesel particulate filter (DPF) used in a partial flow dilution tunnel. The second part studied the regeneration process of PM under the flow rate of oxygen and nitrogen gas of 13.5 L/min with 10%, 15%, and 21% of oxygen gas. The result showed that amount of PM from biodiesel fuel was lower around two times than PM from diesel fuel. The duration in regeneration process of biodiesel's PM was shorter than diesel while increasing of oxygen percentage can reduce regeneration time.
Technical Paper

NOx Reduction with the HC-SCR System over Cu/Zeolite Based Catalysts

2015-09-01
2015-01-2012
Diesel engine is one the effective solutions for reducing CO2 and recognized as a leading candidate for mitigating global warming. To comply with increasingly stringent emission standards, all diesel engines require some sort of NOx control systems such as selective catalytic reduction (SCR) systems. The SCR catalyst for reducing NOx from diesel engines is classified into two groups, urea-SCR and HC-SCR catalyst, respectively. Although the urea-SCR catalyst is widely recognized as promising de-NOx technology in respect to the NOx conversion efficiency, it have some outstanding issues such as ammonia slip, urea injection, storage space, freezing and some infrastructures for supplying urea water solutions. In an attempt to overcome the inherent shortcoming of existing urea-SCR catalyst, hydrocarbons have been considered as alternative reducing agents for SCR process, instead of NH3.
Technical Paper

Comparison Study on Fuel Properties of Biodiesel from Jatropha, Palm and Petroleum Based Diesel Fuel

2014-03-24
2014-01-2017
The increase of air pollution and global warming is a threat for human life. Besides, the price of petroleum is increasing rapidly and the resources are diminishing. This obliged scientists and engineers to look for alternative sources of energy, which are cleaner and more sustainable. Biodiesel, defined as mono-alkyls of esters from vegetable oils and animals fat, is a cleaner renewable fuel and has been considered as the best alternative for petroleum based diesel fuel hence it can be used in any compression ignition engines without any significant modification. The main advantages of using biodiesel are its renewability and better quality of exhaust gas emissions due to their higher content of oxygen. The produce less soot and hence the feed stuck is plant it will regenerate the CO2 by the photosynthesis which ensures the renewability and reduces global warming.
Technical Paper

Physical Characterization of Biodiesel Particle Emission by Electron Microscopy

2013-10-15
2013-32-9150
Nanostructures of diesel and biodiesel engine particulate matters (PMs) were investigated by using a Transmission Electron Microscopy (TEM). The average single particle sizes of biodiesel and diesel PMs are approximately 30-40 nm and 50-60 nm, respectively. Image processing process was used to estimate each carbon platelet length by using TEM image. The average carbon platelet length of biodiesel and diesel PMs are in the range of 0.1-7.0 nm. Moreover, carbon atoms per cubic volume of PMs are approximately 500-900. The result shows that engine load and fuel property are strongly impact on the size of single particle and carbon atom density of particle. This is one of interesting behaviors need to be investigated for better understanding. The results of this research would be used as basic information for design and develop removing process of PM emitted from engine combustion which using in diesel and biodiesel fuels.
Technical Paper

Investigation of Effects of Ignition Improvers on Ignition Delay Time of Ethanol Combustion with Rapid Compression and Expansion Machine

2012-04-16
2012-01-0854
This work investigates the effects of ignition improvers on the ignition and combustion characteristics of hydrous ethanol with 5% by weight water and 1% by weight Lauric acid (Eh95) under simulated diesel engine conditions using the rapid compression and expansion machine (RCEM). Results indicate that hydrous ethanol with commercial additive (ED95) and hydrous ethanol with 5% by weight glycerol ethoxylate in hydrous ethanol exhibit a near identical rate-of-pressure-rise and heat release rate. Ignition delay of hydrous ethanol with 5% by weight glycerol ethoxylate is shorter, but hydrous ethanol with 1% by weight glycerol ethoxylate has longer ignition delay time and different combustion characteristics compared with hydrous ethanol with commercial additive (ED95). Hydrous ethanol with 1% by weight glycerol ethoxylate and hydrous ethanol with 5% by weight glycerol ethoxylate are considered suitable fuels for high compression-ratio diesel engines.
Technical Paper

Low Temperature Starting Techniques for Ethanol Engine without Secondary Fuel Tank

2011-11-08
2011-32-0552
The present study aims to investigate the parameters affecting cold start characteristics of ethanol at low temperature, and suggest a solution to avoid cold starting problem without the installation of second fuel tank. The testing engine is a 125cc volume displacement, single-cylinder four strokes SI engine with fuel injection and ignition timing system controlled by ECU (electronic control unit). The cold starting performance tests were extensively conducted with different percentages of ethanol blends, surrounding temperatures, heating inside combustion chamber, heater injector, pre-cranking without fuel injection, and amount of fuel injection. From the experimental results, when using ethanol fuel in conventional engine, the problem of cold starting was observed at surrounding temperature lower than 20°C for ethanol. Increasing of injection duration can lower the possible cold start temperature of neat ethanol.
Technical Paper

Experimental Investigation in Combustion Characteristics of Ethanol-gasoline Blends for Stratified Charge Engine

2011-11-08
2011-32-0551
The increasing of global energy demand and stringent pollution regulations have promoted research on alternative fuels. In Thailand, ethanol, can be produced from many sources of national agriculture products as renewable fuel, which was strongly promoted by government due to its many merits for use in transportation field. In this study, combustion characteristics of ethanol-gasoline blend (20%, 85%, and 100%) as well as pure gasoline (E0) were investigated by using a swirl-generated constant volume combustion chamber. Flame propagations of different fuel blends were observed by high speed Schlieren photography technique while pressure history data were recorded for detailed combustion analysis. Combustion behavior, combustion duration and rate of pressure rise of all tested fuels were investigated in various swirl intensities and equivalence ratios. In addition, effect of swirl intensities and ethanol concentration on lean misfire limit were also discussed.
Technical Paper

Simultaneous Measurements of Temperatures of Flame and Wall Surface in a Combustion Chamber of Diesel Engine

2011-08-30
2011-01-2047
In order to investigate the combustion phenomena in a combustion chamber of the diesel engine at transient operations, the simultaneous measurements of temperatures of flame and wall surface in a combustion chamber were conducted. The new technique for simultaneous measurements of flame temperature and wall surface was developed. Laser-Induced phosphorescence was used for the measurement of wall surface temperature which was coupled with the flame temperature measurement by a two-color pyrometry. The NOx and soot emissions were also measured simultaneously in transient operations. The relation between the temporal changes of emissions and temperatures of flame and surface wall are discussed. The results show that the temporal change of NOx emission during transient operation is similar to that of the average gas temperature in a chamber. On the other hand, the temporal change of soot emission is similar to neither that of flame temperature nor that of average gas temperature.
Technical Paper

Application of Energy Optimal Control to Energy Management of Hybrid Vehicle

2011-05-17
2011-39-7244
Energy optimal control theory (EOC) is applied to the energy flow control of a hybrid electric vehicle. Since the differential equation is solved analytically, the control law can be easily implemented in real time. Because the objective function is described in power form that permits negative value, not only the energy consumption is minimized but also the energy regeneration by the motor is maximized. In the simulation for the 10-mode driving, it is shown that the fuel cost of EOC is 15% lower than the rule based control (RBC).
Technical Paper

Extension of Lean and Diluted Combustion Stability Limits by Using Repetitive Pulse Discharges

2010-04-12
2010-01-0173
A newly developed small-sized IES (inductive energy storage) circuit with a semiconductor switch at turn-off action was successfully applied to an ignition system. This IES circuit can generate repetitive nanosecond pulse discharges. An ignition system using repetitive nanosecond pulse discharges was investigated as an alternative to conventional spark ignition systems in the previous papers. Experiments were conducted using constant volume chamber for CH₄ and C₃H₈-air mixtures. The ignition system using repetitive nanosecond pulse discharges was found to improve the inflammability of lean combustible mixtures, such as extended flammability limits, shorted ignition delay time, with increasing the number of pulses for CH₄ and C₃H₈-air mixtures under various conditions. The mechanisms for improving the inflammability were discussed and the effectiveness of IES circuit under EGR condition was also verified.
Journal Article

Simultaneous Measurements of Aromatic Hydrocarbons in Exhaust using a Laser Ionization Method

2009-11-02
2009-01-2742
A simultaneous multi-composition analyzing (SMCA) resonance enhanced multi-photon ionization (REMPI) system was used to investigate gasoline engine exhaust. Observed peaks for exhaust were smaller mass numbers than those from diesel exhaust. However, large species up to three ring aromatics were observed suggesting that soot precursor forms even in the gasoline engine. At low catalyst temperature condition, the reduction efficiencies of a three-way catalyst were higher for higher mass numbers. This result indicates that the larger species accumulate in the catalyst or elsewhere due to their lower vapor pressures. To evaluate the emission of low volatility species, the accumulation should be taken into account. In the hot mode, reduction efficiencies for aromatic species of three-way catalyst were almost 99.5% however, they fall to 70% in the cold start condition.
Technical Paper

Development of a Novel Ignition System Using Repetitive Pulse Discharges: Ignition Characteristics of Premixed Hydrocarbon-Air Mixtures

2008-04-14
2008-01-0468
A newly developed small-sized IES (inductive energy storage) circuit with static induction thyristor at turn-off action was successfully applied to an ignition system. This IEC circuit can generate repetitive nanosecond pulse discharges. In this paper, the ignition system using repetitive nanosecond pulse discharges was investigated as an alternative to conventional spark ignition systems. The experiments were conducted using spherically expanding flame configuration for CH4 and C3H8-air mixtures under various conditions. In conclusions, the ignition system using repetitive nanosecond pulse discharges was found to extend lean flammability limits compared with conventional spark ignition systems. In addition, the ignition system using repetitive nanosecond pulse discharges could shorten ignition delay time.
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