Port Fuel Injection Spark Ignition Engine Research Articles

Environmental, combustion, and performance investigation of low viscous biofuel in port fuel injection spark-ignition engine

Environmental, combustion, and performance investigation of low viscous biofuel in port fuel injection spark-ignition engine

Study on hydrogen substitution in a compressed natural gas spark-ignition passenger car engine

Hydrogen substitution in applications fueled by compressed natural gas arises as a potential alternative to fossil fuels, and it may be the key to an effective hydrogen economy transition. The reduction of greenhouse gas emissions, especially carbon dioxide and unburned methane, as hydrogen is used in transport and industry applications, makes its use an attractive option for a sustainable future. The purpose of this research is to examine the gradual adoption of hydrogen as a fuel for light-duty transportation. Particularly, the study focuses on evaluating the performance and emissions of a single-cylinder port fuel injection spark-ignition engine as hydrogen is progressively increased in the natural gas-based fuel blend. Results identify the optimal conditions for air dilution and engine operation parameters to achieve the best performance. They corroborate that the dilution rate has to be adjusted to control pollutant emissions as the percentage of hydrogen is increased. Moreover, the study identifies the threshold for hydrogen substitution below which the reduction of carbon dioxide emissions due to efficiency gains is negligible compared to the reduction of the carbon content in the fuel blend. These findings will help reduce the environmental footprint of light-duty transportation not only in the long term but also in the short and medium terms.

Investigation on injection strategy affecting the mixture formation and combustion of a heavy-duty spark-ignition methanol engine

Methanol is thought as a carbon neutral fuel and one of the most promising alternative fuels for spark-ignition (SI) engine. On the basic combustion theory of SI engines, mixture formation plays an important role in the SI engine performance. However, there is a lack of investigation on the mixture formation process of heavy-duty (HD) port fuel injection (PFI) SI methanol engines. Therefore, experiments and simulations were conducted on a HD PFI SI engine fueled with pure methanol. The effects of the injection timing (αinj) on the mixture formation process, combustion and emission characteristics were investigated. Methanol engine performance can be predicted by the mixture homogeneity which is deeply affected by injection timing. When αinj was 240°CA, 360°CA and 480°CA, there were three typical mixture formation modes, namely “spray”, “premix and spray” and “premix” mode, respectively. The mixture homogeneity increased first and then decreased while the in-cylinder temperature at the spark timing increased monotonically as αinj varied from 240°CA to 480°CA at the interval of 120°CA. The “premix and spray” mode was the optimal mixture formation strategy from the perspective of promoting mixture homogeneity and decreasing the in-cylinder mixture temperature. When αinj was from 120°CA to 300°CA, the leaner mixture around the spark plug and lower mixture prolonged or retarded CA0-10, CA10-90 and CA50. The above combustion characteristics contributed to a lower engine brake thermal efficiency (BTE) at αinj of 120°CA to 300°CA. As αinj varied from 0°CA to 720°CA, HC emissions increased first and then decreased while CO emissions did the opposite. Both HC and CO emissions at αinj of 360°CA were at low levels. The more HC emission was caused by the more regions with the richer mixture in the crevice formed by the piston and liner. The CO emission was determined by the volume of regions with the richer mixture in the combustion chamber and in-cylinder mixture temperature. The “premix and spray” mode should be adopted to improve the BTE and reduce both HC and CO emissions.

Modeling of a port fuel injection spark-ignition engine with different compression ratios using methanol blends with the response surface methodology

In this study, the response surface methodology was applied to verify the optimum compression ratio, methanol percentage, and engine load in order to obtain the best levels of engine response that will occur when using methanol (0, 10, and 20% by vol.) in a spark-ignition engine under different compression ratio (6.0:1, 8.0:1, and 10.0:1) and engine load (8, 10, and 12 kg) conditions. A response surface methodology aided by analysis of variance was created using the three-factor and three-level central composite full design with the results of the experiment. With the created model, optimum methanol percentage, compression ratio, and engine load levels corresponding to the finest brake thermal efficiency, brake-specific fuel consumption, carbon monoxide, carbon dioxide, hydrocarbon, and nitrogen oxide emission levels were determined. According to the optimization results, the optimum methanol percentage, compression ratio, and engine load were found to be 10.5%, 6.0:1, and 12 kg, respectively. Hydrocarbon, nitrogen oxide, carbon monoxide, carbon dioxide, brake thermal efficiency , and brake-specific fuel consumption corresponding to optimum operating conditions were determined as 63.568 ppm, 840.643 ppm, 0.365%, 14.059%, 28.199%, and 0.286 kg/kWh, respectively. To test the reliability of the response surface methodology results, experiments with optimal methanol, compression ratio, and engine load were carried out and compared with the response surface methodology findings. As a result, it can be said that the response surface methodology is a successful application for the optimization of a spark-ignition engine using methanol as an alternative fuel with different engine parameters.

Comprehensive investigation of using n-butanol/gasoline blends in a port-fuel injection spark-ignition engine

Comprehensive investigation of using n-butanol/gasoline blends in a port-fuel injection spark-ignition engine

Comprehensive investigation of using n-butanol/gasoline blends in a port-fuel injection spark-ignition engine

Comprehensive investigation of using n-butanol/gasoline blends in a port-fuel injection spark-ignition engine

Comprehensive analysis of the combustion of low carbon fuels (hydrogen, methane and coke oven gas) in a spark ignition engine through CFD modeling

The use of low carbon fuels (LCFs) in internal combustion engines is a promising alternative to reduce pollution while achieving high performance through the conversion of the high energy content of the fuels into mechanical energy. However, optimizing the engine design requires deep knowledge of the complex phenomena involved in combustion that depend on the operating conditions and the fuel employed. In this work, computational fluid dynamics (CFD) simulation tools have been used to get insight into the performance of a Volkswagen Polo 1.4L port-fuel injection spark ignition engine that has been fueled with three different LCFs, coke oven gas (COG), a gaseous by-product of coke manufacture, H2 and CH4. The comparison is made in terms of power, pressure, temperature, heat release, flame growth speed, emissions and volumetric efficiency. Simulations in Ansys® Forte® were validated with experiments at the same operating conditions with optimal spark advance, wide open throttle, a wide range of engine speed (2000–5000 rpm) and air-fuel ratio (λ) between 1 and 2. A sensitivity analysis of spark timing has been added to assess its impact on combustion variables. COG, with intermediate flame growth speed, produced the greatest power values but with lower pressure and temperature values at λ = 1.5, reducing the emissions of NO and the wall heat transfer. The useful energy released with COG was up to 16.5% and 5.1% higher than CH4 and H2, respectively. At richer and leaner mixtures (λ = 1 and λ = 2), similar performances were obtained compared to CH4 and H2, combining advantages of both pure fuels and widening the λ operation range without abnormal combustion. Therefore, suitable management of the operating conditions maximizes the conversion of the waste stream fuel energy into useful energy while limiting emissions.

Simultaneous optimization of multiple engine parameters of a 1-heptanol / gasoline fuel blends operated a port-fuel injection spark-ignition engine using response surface methodology approach

Due to increasing air pollution and decreasing fuel reserves, the search for environmentally friendly fuels continues and a lot of time and money are spent in the experiments for these searches. Therefore, it is very important to be able to determine the optimal parameter levels for a fuel's use in the engine through several experiments. For this purpose, in this study, the design of experiments (DoE)-based response surface methodology (RSM) was used to determine the optimum compression ratio (CR), engine load, and 1-heptanol percentage in a spark ignition (SI) engine to obtain the best performance such as brake thermal efficiency (BTHE), brake specific fuel consumption (BSFC) and emission values such as carbon monoxide (CO), carbon dioxide (CO2), hydrocarbon (HC) and nitrogen oxide (NOx). The data required for the RSM model were obtained from the experiments performed at three different 1-heptanol percentages (0, 10%, and 20%), three different CRs (6.0:1, 8.0:1, and 10.0:1), and three different engine loads (4, 8, and 12 kg). Optimum operating parameters to achieve the best performance and emission values were determined as 8% 1-heptanol, 10.0:1 CR, and 6 kg engine load. The BTHE, BSFC, CO, CO2, HC, and NOx were found to be 26.03%, 0.32 kg/kWh, 0.56%, 15.07%, 182.54 ppm, and 676.16 ppm according to optimum working parameters, respectively. In addition, according to the validation study, the error rates between the optimum results and the experimental results were acceptable between 0.74% and 8.96%. Experimental results reveal that 10% 1-heptanol addition improved BTHE and BSFC by an average of 5% and 2.5%, respectively, but did not affect NOx much. With the addition of 20% 1-heptanol, the CO emission was improved by an average of 8.5%. In terms of HC and CO2, the effect of 1-heptanol was negative. By increasing the compression ratio to 10, BTHE, BSFC, CO, and HC were positively affected, while CO2 and NOx emissions were negatively affected. It is thought that this study will be a reference study since it provides optimum operating parameters of the engine when 1-heptanol will be used as an alternative fuel in the gasoline engine.

Effect of Cylinder-by-Cylinder Variation on Performance and Gaseous Emissions of a PFI Spark Ignition Engine: Experimental and 1D Numerical Study

Combustion stability, engine efficiency and emissions in a multi-cylinder spark-ignition internal combustion engines can be improved through the advanced control and optimization of individual cylinder operation. In this work, experimental and numerical analyses were carried out on a twin-cylinder turbocharged port fuel injection (PFI) spark-ignition engine to evaluate the influence of cylinder-by-cylinder variation on performance and pollutant emissions. In a first stage, experimental tests are performed on the engine at different speed/load points and exhaust gas recirculation (EGR) rates, covering operating conditions typical of Worldwide harmonized Light-duty vehicles Test Cycle (WLTC). Measurements highlighted relevant differences in combustion evolution between cylinders, mainly due to non-uniform effective in-cylinder air/fuel ratio. Experimental data are utilized to validate a one-dimensional (1D) engine model, enhanced with user-defined sub-models of turbulence, combustion, heat transfer and noxious emissions. The model shows a satisfactory accuracy in reproducing the combustion evolution in each cylinder and the temperature of exhaust gases at turbine inlet. The pollutant species (HC, CO and NOx) predicted by the model show a good agreement with the ones measured at engine exhaust. Furthermore, the impact of cylinder-by-cylinder variation on gaseous emissions is also satisfactorily reproduced. The novel contribution of present work mainly consists in the extended numerical/experimental analysis on the effects of cylinder-by-cylinder variation on performance and emissions of spark-ignition engines. The proposed numerical methodology represents a valuable tool to support the engine design and calibration, with the aim to improve both performance and emissions.

Individual Cylinder Combustion Optimization to Improve Performance and Fuel Consumption of a Small Turbocharged SI Engine

Stringent exhaust emission and fuel consumption regulations impose the need for new solutions for further development of internal combustion engines. With this in mind, a refined control of the combustion process in each cylinder can represent a useful and affordable way to limit cycle-to-cycle and cylinder-to-cylinder variation reducing CO2 emission. In this paper, a twin-cylinder turbocharged Port Fuel Injection–Spark Ignition engine is experimentally and numerically characterized under different operating conditions in order to investigate the influence of cycle-to-cycle variation and cylinder-to-cylinder variability on the combustion and performance. Significant differences in the combustion behavior between cylinders were found, mainly due to a non-uniform effective in-cylinder air/fuel (A/F) ratio. For each cylinder, the coefficients of variation (CoVs) of selected combustion parameters are used to quantify the cyclic dispersion. Experimental-derived CoV correlations representative of the engine behavior are developed, validated against the measurements in various speed/load points and then coupled to an advanced 1D model of the whole engine. The latter is employed to reproduce the experimental findings, taking into account the effects of cycle-to-cycle variation. Once validated, the whole model is applied to optimize single cylinder operation, mainly acting on the spark timing and fuel injection, with the aim to reduce the specific fuel consumption and cyclic dispersion.

Soot contamination of engine oil – the case of a small turbocharged spark-ignition engine

The paper presents the results of thermogravimetric tests of engine oil used in a small turbocharged spark-ignition engine. The main observation from the research was a significant soot contamination of engine oil, that appears even at its low mileage. This indicates that also in the case of port fuel injection spark-ignition engine, high particulate matter emissions may occur. It may therefore turn out that the small city car can be more harmful to the environment than much larger vehicles. A rapid soot contamination of the oil in this engine indicates as well that the oil change interval should be shortened.

Effects of knocking on the performance and emissions of a single cylinder SI engine fueled with a fuel blend of iso-octane and aromatic hydrocarbons

This study investigated the effects of knocking on the performance and emissions of a single cylinder port fuel injection spark-ignition engine. Three types of hydrocarbon compounds were used as fuels in this study: iso-octane, aromatic hydrocarbons, and a mixed fuel composed of iso-octane and aromatic hydrocarbons. The ignition timing was varied to investigate the effects of fuel composition and knocking from 10° to 40° before top dead center. The experimental results indicated that as the fuel evaporation improved, the ignition delay and combustion duration were shortened. Additionally, the knocking of fuels with these characteristics occurred earlier than the other fuels, and the knocking intensity of these fuels was stronger. A fuel with a greater iso-octane content improved the engine performance, including the brake mean effective pressure (BMEP) and brake thermal efficiency (BTE), better than a fuel containing a greater content of aromatic hydrocarbons. The intensity of the knocking increased as the ignition timing was advanced, thereby causing a decrease in the BMEP and BTE. Additionally, the knocking intensities of fuels with high iso-octane contents were weaker than the other examined fuels. There were no significant changes in gaseous emissions, including the total hydrocarbon and NOx emissions when knocking occurred. However, particulate emissions sharply increased as the knocking intensity increased.

Comparative performance of coke oven gas, hydrogen and methane in a spark ignition engine

In this study, coke oven gas (COG), a by-product of coke manufacture with a high volumetric percentage of H2 and CH4, has been identified as auxiliary support and promising energy source in stationary internal combustion engines. Engine performance (power and thermal efficiency) and emissions (NOx, CO, CO2 and unburned hydrocarbons) of COG, pure H2 and pure CH4 have been studied on a Volkswagen Polo 1.4 L port-fuel injection spark ignition engine. Experiments have been done at optimal spark advance and wide open throttle, at different speeds (2000–5000 rpm) and various air-fuel ratios (λ) between 1 and 2. The obtained data revealed that COG combines the advantages of pure H2 and pure CH4, widening the λ range of operation from 1 to 2, with very good performance and emissions results comparable to pure gases. Furthermore, it should be highlighted that this approach facilitates the recovery of an industrial waste gas.

Experimental Comparative Study on Performance and Emissions of E85 Adopting Different Injection Approaches in a Turbocharged PFI SI Engine

This study examines the effects of ethanol and gasoline injection mode on the combustion performance and exhaust emissions of a twin cylinder port fuel injection (PFI) spark ignition (SI) engine. Generally, when using gasoline–ethanol blends, alcohol and gasoline are externally mixed with a specified blending ratio. In this activity, ethanol and gasoline were supplied into the intake manifold into two different ways: through two separated low pressure fuel injection systems (Dual-Fuel, DF) and in a blend (mix). The ratio between ethanol and gasoline was fixed at 0.85 by volume (E85). The initial reference conditions were set running the engine with full gasoline at the knock limited spark advance boundary, according to the standard engine calibration. Then E85 was injected and a spark timing sweep was carried out at rich, stoichiometric, and lean conditions. Engine performance and gaseous and particle exhaust emissions were measured. Adding ethanol could remove over-fueling with an increase in thermal efficiency without engine load penalties. Both ethanol and charge leaning resulted in a lowering of CO, HC, and PN emissions. DF injection promoted a faster evaporation of gasoline than in blend, shortening the combustion duration with a slight increase in THC and PN emissions compared to the mix mode.

Experimental investigation on combustion, performance, and emissions characteristics of butanol as an oxygenate in a spark ignition engine

Ethanol is known as the most widely used alternative fuel for spark-ignition engines. Compared to it, butanol has proved to be a very promising renewable fuel in recent years for desirable properties. The conjoint analysis on combustion, performance, and emissions characteristics of a port fuel injection spark-ignition engine fueled with butanol–gasoline blends was carried out. In comparison with butanol–gasoline blends with various butanol ratio (0–60 vol% referred as G100~B60) and conventional alcohol alternative fuels (methanol, ethanol, and butanol)–gasoline blends, it shows that B30 performs well in engine performance and emissions, including brake thermal efficiency, brake-specific fuel consumption, carbon monoxide, unburned hydrocarbons, and nitrogen oxides. Then, B30 was compared with G100 under various equivalence ratios ( Φ = 0.83–1.25) and engine loads (3 and 5-bar brake mean effective pressure). In summary, B30 presents an advanced combustion phasing, which leads to a 0.3%–2.8% lower brake thermal efficiency than G100 as the engine was running at the spark timing of gasoline’s maximum brake torque (MBT). Therefore, the sparking timing should be postponed when fueled with butanol–gasoline blends. For emissions, the lower carbon monoxide (2.3%–8.7%), unburned hydrocarbons (12.4%–27.5%), and nitrogen oxides (2.8%–19.6%) were shown for B30 compared with G100. Therefore, butanol could be a good alternative fuel to gasoline for its potential to improve combustion efficiency and reduce pollutant emissions.

Experimental Investigation on the Emissions of a Port Fuel Injection Spark Ignition Engine Fueled with Methanol–Gasoline Blends

The prospect of using methanol as an alternative fuel for vehicles in China is enticing because of its good combustion properties, low production cost, and renewable capacity, but the in-cylinder combustion of methanol also brings extra emissions concerns, such as alcohols and aldehydes. For the impact of methanol–gasoline blends on the pollutant emissions of spark ignition (SI) engines to be investigated, a GEELY MR479Q port fuel injection SI engine was selected for tests of burning different methanol–gasoline blends at wide-open throttle operating conditions, and an AVL Fourier-transform infrared multicomponent gas analyzer was used to measure all of the emissions. Test results show that the methanol-containing fuel blends had positive effects on the engine-out regulated emissions. Nitrogen oxide, carbon monoxide, and nonmethane hydrocarbon emissions were all dramatically reduced when the test engine was fueled with methanol–gasoline blends. Other hydrocarbon emissions such as ethylene, propylene, and s...

Experimental investigation of the effects of AFR, spark advance and EGR on nanoparticle emissions in a PFI SI engine

Nanoparticle emissions continue to catch the attention because of their adverse health effects and their impact on the environment. Internal combustion engines are the major source of particle emissions in urban areas. The legislation proposes a stronger restriction for both diesel and gasoline engines. In particular, the European particle measurement program (PMP) has introduced particle number regulation for both diesel and gasoline engines. Great efforts are then devoted to the reduction of the particle emissions; nonetheless, the mechanisms governing particle formation are still not fully understood, neither for diesel nor for gasoline engines.The aim of the paper is the experimental characterization of particles emitted from a Port Fuel Injection (PFI) gasoline engine in steady state operating conditions. In particular, the impact of engine control variables (i.e. injection time and spark advance) and emissions control technologies (i.e. exhaust gas recirculation—EGR) on particle size and number was deeply investigated. Moreover, the effect of the dilution conditions was also analyzed. The investigation was carried out at the exhaust of a 1242cc PFI spark ignition (SI) engine. The engine test bench was equipped with a full-pass engine control system dSPACE MicroAutoBox and a scanning mobility particle sizer (SMPS) for particle counting and sizing.

Comparison of regulated and non-regulated pollutants with iso-octane/butanol and iso-octane/ethanol blends in a port-fuel injection Spark-Ignition engine

Experimental tests were carried out on a single-cylinder port-fuel injection SI engine to quantify the potential of butanol/isooctane blends (with an alcohol concentration of 0%vol, 25%vol, 50%vol, 75%vol and 100%vol) to reduce regulated pollutants (CO, CO2, Nox and THC), and non-regulated pollutants (methane, acetylene, ethylene, benzene, acetaldehyde and formaldehyde), without deteriorating the engine performance. A comparison with results obtained for ethanol/isooctane blends is given. It was observed that the addition of alcohol results in an increase of the fuel consumption of about 30% with butanol and 60% with ethanol, but only a slight increase (about 2%) in CO2 emissions. A strong decrease in HC and Nox emissions was obtained for both alcohols. For the non-regulated pollutants, the addition of ethanol induces a reduction of up to 100% in ethylene emissions, whereas with butanol, a strong increase is observed. The addition of butanol induces a greater decrease, of up to 100%, in methane emissions than ethanol. For benzene emissions, a strong reduction is observed for both alcohols. Moreover, the addition of alcohol engenders a reduction in acetylene emissions and an increase in formaldehyde emissions, but at different levels for both alcohols. Finally, no effects or trends were distinguishable for acetaldehyde and CO emissions.

Effect of the fuel injection strategy on the combustion process in a PFI boosted spark-ignition engine

In this paper, the effect of different fuel injection strategies on the combustion process was investigated in a boosted port fuel injection spark-ignition engine. The experiments were performed on a partially transparent single-cylinder engine, equipped with a four-valve head and boost device. Single and double fuel injection strategies were tested in the open-valve condition. Moreover, two fuel injection pressures were considered. Optical techniques based on 2D-digital imaging were used to follow the flame propagation in the combustion chamber. In particular, the diffusion-controlled flames near valves and on cylinder walls due to the fuel film burning were studied. Two-colour pyrometry was employed to measure soot concentration. In-cylinder optical investigations were correlated to the engine parameters and to the exhaust emissions.

Particle and nanoparticle characterization at the exhaust of internal combustion engines

The aim of this work is the characterization of the emissions of exhaust particles in terms of number size distribution and chemical—physical properties. Laser-induced incandescence and broadband ultraviolet—visible extinction and scattering spectroscopy were used at the exhaust of a common-rail diesel engine and of a port fuel injection (PFI) spark ignition (SI) engine. The optical results were compared with size distributions obtained with an electrical low-pressure impactor and a scanning mobility particle sizer. Moreover, the fundamental engine parameters and the particulate mass and gas concentrations were measured using conventional instrumentation. With respect to the diesel engine, the effect of the exhaust after-treatment was investigated. The exhaust gas recirculation influenced the particle size distribution in terms of number concentration owing to the formation of accumulation mode particles. The catalysed diesel particulate filter strongly reduced the particle number concentration in the loading phase. Effects on the chemical nature of the particles were observed during the filter regeneration phase. With respect to the PFI SI engine, high number concentrations of nanoparticles ( D<50nm) were measured for all the engine operating conditions. The chemical nature of the nanoparticles was investigated.