Showing papers on "Spark-ignition engine published in 2016"

Review on bioethanol as alternative fuel for spark ignition engines

Abstract: Bioethanol fuel obtained from biomass and bioenergy crops has been proclaimed as one of the feasible alternative to gasoline fuel, as it is considered to be clean, renewable and green. In this review, the bioethanol production techniques from different lignocellulosic biomass, and its potential ethanol yield are studied. Moreover, this paper has reviewed the effects of bioethanol fuel blends on spark ignition engine combustion characteristics (i.e. cylinder pressure, cylinder temperature, flame speed, combustion efficiency, combustion duration, heat release rate, knocking and cold start); engine performance parameters (i.e. torque, brake power, brake specific fuel consumption, brake mean effective pressure, brake thermal efficiency and volumetric efficiency); and emission characteristics (i.e. carbon monoxide, oxides of nitrogen, carbon dioxide, unburned hydrocarbon and other unregulated emissions). Recently, many researchers produced bioethanol from herbaceous, industrial and municipal solid wastes (MSW) instead of agriculture and woody biomass. Most of the engine test results showed a remarkable improvement in engine performance and enhanced combustion characteristics for bioethanol fuel. In addition, the carbon monoxide and unburned hydrocarbon emissions decreased. Conversely, carbon dioxide and oxides of nitrogen emissions were not significantly reduced. Furthermore, there was no significant reduction of unregulated emissions, such as aromatics, acetaldehyde, and carbonyls.

Performance and emissions assessment of n-butanol–methanol–gasoline blends as a fuel in spark-ignition engines

Abstract: The sleek of using alternatives to gasoline fuel in internal combustion engines becomes a necessity as the environmental problems of fossil fuels as well as their depleted reserves. This research presents an experimental investigation into a new blended fuel; the effects of n-butanol–methanol–gasoline fuel blends on the performance and pollutant emissions of an SI (spark-ignition) engine were examined. Four test fuels (namely 0, 3, 7 and 10 volumetric percent of n-butanol–methanol blends at equal rates, e.g., 0%, 1.5%, 3.5% and 5% for n-butanol and methanol, in gasoline) were investigated in an engine speed range of 2600–3400 r/min. In addition, the dual alcohol (methanol and n-butanol)–gasoline blends were compared with single alcohol (n-butanol)–gasoline blends (for the first time) as well as with the neat gasoline fuel in terms of performance and emissions. The experimental results showed that the addition of low content rates of n-butanol–methanol to neat gasoline adversely affects the engine performance and exhaust gas emissions as compared to the results of neat gasoline and single alcohol–gasoline blends; in particular, a reduction in engine volumetric efficiency, brake power, torque, in-cylinder pressure, exhaust gas temperature and CO2 emissions and an increase in concentrations of CO and UHC (unburned hydrocarbons) emissions were observed for the dual alcohols. However, higher rates of n-butanol–methanol blended in gasoline were observed to improve the SI engine performance parameters and emission concentration. Oppositely the higher rates of single alcohol–gasoline blends were observed to provide adverse results, e.g., higher emissions and lower performance than those of lower rates of single alcohol. Finally, dual alcohol–gasoline blends could exceed (i.e. provide higher performance and lower emissions) single alcohol–gasoline blends and pure gasoline at higher rates (>10 vol.%) in the blend and, in turn, it is recommended to be used at high rate conditions.

Knock Resistance and Fine Particle Emissions for Several Biomass-Derived Oxygenates in a Direct-Injection Spark-Ignition Engine

Abstract: Several high octane number oxygenates that could be derived from biomass were blended with gasoline and examined for performance properties and their impact on knock resistance and fine particle emissions in a single cylinder direct-injection spark-ignition engine. The oxygenates included ethanol, isobutanol, anisole, 4-methylanisole, 2-phenylethanol, 2,5-dimethyl furan, and 2,4-xylenol. These were blended into a summertime blendstock for oxygenate blending at levels ranging from 10 to 50 percent by volume. The base gasoline, its blends with p-xylene and p-cymene, and high-octane racing gasoline were tested as controls. Relevant gasoline properties including research octane number (RON), motor octane number, distillation curve, and vapor pressure were measured. Detailed hydrocarbon analysis was used to estimate heat of vaporization and particulate matter index (PMI). Experiments were conducted to measure knock-limited spark advance and particulate matter (PM) emissions. The results show a range of knock resistances that correlate well with RON. Molecules with relatively low boiling point and high vapor pressure had little effect on PM emissions. In contrast, the aromatic oxygenates caused significant increases in PM emissions (factors of 2 to 5) relative to the base gasoline. Thus, any effect of their oxygen atom on increasing local air-fuel ratio was outweighed by their low vapor pressure and high double-bond equivalent values. For most fuels and oxygenate blend components, PMI was a good predictor of PM emissions. However, the high boiling point, low vapor pressure oxygenates 2-phenylethanol and 2,4-xylenol produced lower PM emissions than predicted by PMI. This was likely because they did not fully evaporate and combust, and instead were swept into the lube oil. CITATION: Ratcliff, M., Burton, J., Sindler, P., Christensen, E. et al., \"Knock Resistance and Fine Particle Emissions for Several BiomassDerived Oxygenates in a Direct-Injection Spark-Ignition Engine,\" SAE Int. J. Fuels Lubr. 9(1):2016, doi:10.4271/2016-01-0705. 2016-01-0705 Published 04/05/2016 Copyright © 2016 SAE International doi:10.4271/2016-01-0705 saefuel.saejournals.org 59 NREL/CP-5400-65398. Posted with permission. Presented at the SAE 2016 World Congress & Exhibition, 12-14 April 2016, Detroit, Michigan.

Influence of intake geometry variations on in-cylinder flow and flow–spray interactions in a stratified direct-injection spark-ignition engine captured by time-resolved particle image velocimetry

Abstract: Time-resolved particle image velocimetry and Mie-scattering of fuel droplets at 16 kHz were used to capture simultaneously the temporal evolution of the in-cylinder flow field and spray formation within a direct-injection spark-ignition engine. The engine was operated in stratified combustion mode, with stratified mixtures created by a triple injection late in the compression stroke. The impact of geometric variation of the intake port on in-cylinder flow and flow–spray interactions was investigated, focusing on the second injection, since it provides ignitable mixtures at the time of ignition and is subject to strong fluctuations, rather than the first injection, which is very reproducible. Flow field statistics conditioned on the spray shape of the second injection revealed regions with macroscopic cycle-to-cycle flow variations, which correlated with the spray for all recorded cycles. The flow–spray interaction was traced back to before the first injection using correlation analysis, which revealed tha...

Hydrogen-fueled internal combustion engines

Abstract: Use of hydrogen as a fuel for internal combustion engines has been the topic of research for over a century. The earlier efforts were sporadic and mainly confined to the laboratory. At present, there is a renewed spate of interest in hydrogen fuel because of its ability to provide long-term solutions to the energy–environment crises. There have been numerous studies of the hydrogen engine in several parts of the world. It is beyond the scope of this chapter to discuss the efforts and attainments of all these efforts. Technical solutions have already been provided by several researchers, industries, and government organizations to counter the characteristic problems leading to preignition, backfire, rough combustion, and high rate of pressure rise. Modest efforts have been made in this chapter to bring out the technological route of operating both the spark ignition (SI) and compression ignition engines with hydrogen fuel to obtain optimum performance and low exhaust emission characteristics without any undesirable combustion phenomena. As far as the SI engines are concerned, fuel induction techniques form the most critical part of system development. Design features of fuel induction techniques for SI engines are discussed for an optimum engine configuration. The technical features of hydrogen supplementation and the potential of blended fuels with hydrogen are also highlighted. The broad differences between the conventional engine and the hydrogen-fueled engine are discussed. Last but not the least, this chapter also highlights the future outlook and market potential of the hydrogen-fueled engine at present and analyses the emerging trend toward its penetration in the market.

Spark Ignition Engine Combustion, Performance and Emission Products from Hydrous Ethanol and Its Blends with Gasoline

Abstract: This paper reviews the serviceability of hydrous ethanol as a clean, cheap and green renewable substitute fuel for spark ignition engines and discusses the comparative chemical and physical properties of hydrous ethanol and gasoline fuels. The significant differences in the properties of hydrous ethanol and gasoline fuels are sufficient to create a significant change during the combustion phase of engine operation and consequently affect the performance of spark-ignition (SI) engines. The stability of ethanol-gasoline-water blends is also discussed. Furthermore, the effects of hydrous ethanol, and its blends with gasoline fuel on SI engine combustion characteristics, cycle-to-cycle variations, engine performance parameters, and emission characteristics have been highlighted. Higher water solubility in ethanol‑gasoline blends may be obviously useful and suitable; nevertheless, the continuous ability of water to remain soluble in the blend is significantly affected by temperature. Nearly all published engine experimental results showed a significant improvement in combustion characteristics and enhanced engine performance for the use of hydrous ethanol as fuel. Moreover, carbon monoxide and oxides of nitrogen emissions were also significantly decreased. It is also worth pointing out that unburned hydrocarbon and carbon dioxide emissions were also reduced for the use of hydrous ethanol. However, unregulated emissions such as acetaldehyde and formaldehyde were significantly increased.

A numerical study on the effects of EGR and spark timing to combustion characteristics and NOx emission of a GDI engine

Abstract: EGR is one of the most significant strategies for reducing especially nitrogen oxides (NOx) emissions from internal combustion engines. The thermal efficiency of spark ignition engines is lower than compression ignition engines because of its lower compression ratio. If the compression ratio is increased to obtain higher thermal efficiency, there may be a knocking tendency in spark ignition engines. EGR can be used in order to reduce NOx emissions and avoid knocking phenomena at higher compression ratios. In-cylinder temperature at the end of combustion is decreased and heat capacity of fresh charge is increased when EGR applied. Besides EGR, spark timing is another significant parameter for reducing exhaust emissions such as nitrogen oxides, and unburned hydrocarbon (UHC). In this study the effects of EGR and spark timing on spark ignition engine were investigated numerically. KIVA codes were used in order to model combustion process. The combustion process has been modeled for a single cylinder,...