Effect of Injection Timing on Combustion, NOx, Particulate Matter and Soluble Organic Fraction Composition in a 2-Stroke Tier 0+ Locomotive Engine

2012 ◽  
Vol 135 (1) ◽  
Author(s):  
Stanislav V. Bohac ◽  
Eric Feiler ◽  
Ian Bradbury
Keyword(s):  
Timing Analysis ◽  
Injection Timing ◽  
Oil Consumption ◽  
Peak Cylinder Pressure ◽  
Study Results ◽  
Release Analysis ◽  
Soluble Organic Fraction ◽  
High Fraction ◽  
Locomotive Engine ◽  
Effective Path

The effects of injection timing on combustion, NOx, PM mass and composition from a 2-stroke turbocharged Tier 0+ locomotive diesel engine are investigated in this study. Results provide insight into how injection timing affects combustion and emissions in this family of engine and identifies areas of potential future emissions reduction. For a range of injection timings at a medium load (notch 5) operating condition, the majority of PM mass is insolubles (81–89%), while the soluble component of PM (SOF) accounts for a smaller fraction (11–19%) of total PM mass. The SOF is 66–80% oil-like C22-C30+ hydrocarbons, with the remainder being fuel-like C9-C21 hydrocarbons. A heat release analysis is used to calculate mass fraction burned curves and elucidates how injection timing affects combustion. Retarding injection timing retards combustion phasing, decreases peak cylinder pressure and temperature, and increases expansion pressure and temperature. Results show that insolubles and fuel-like hydrocarbons increase, and oil-like hydrocarbons decrease with later injection timing. Analysis suggests that insolubles and fuel-like HC increase due to lower peak combustion temperature, while oil-like HC, which are distributed more widely throughout the cylinder, decrease due to higher expansion temperatures. The net result is that total PM mass increases with retarded combustion phasing, mostly due to increased insolubles. Considering the high fraction of insoluble PM (81–89%) at all injection timings tested at notch 5, steps taken to reduce PM elemental carbon should be the most effective path for future reductions in PM emissions. Further reductions in oil consumption may also reduce PM, but to a smaller extent.

Effect of Injection Timing on Combustion, NOx, Particulate Matter and Soluble Organic Fraction Composition in a 2-Stroke Tier 0+ Locomotive Engine

2012 ◽  
Author(s):  
Stanislav V. Bohac ◽  
Eric Feiler ◽  
Ian Bradbury
Keyword(s):  
Timing Analysis ◽  
Emissions Reduction ◽  
Injection Timing ◽  
Oil Consumption ◽  
Peak Cylinder Pressure ◽  
Release Analysis ◽  
Soluble Organic Fraction ◽  
High Fraction ◽  
Locomotive Engine ◽  
Effective Path

This study investigates how injection timing affects combustion, NOx, PM mass and composition from a 2-stroke turbocharged locomotive diesel engine fitted with an early-development Tier 0+ emissions kit. The objective of the work is to gain insight into how injection timing affects combustion and emissions in this family of engines, modified to meet the newly implemented Tier 0+ emissions requirements, and to identify areas of potential future emissions reduction. For a range of injection timings at a medium load (notch 5) operating condition, the majority of PM mass is comprised of insolubles (81–89%), while the soluble component of PM (SOF) accounts for a smaller fraction (11–19%) of total PM mass. The SOF is 66–80% oil-like C22–C30+ hydrocarbons, with the remainder being fuel-like C9–C21 hydrocarbons. A heat release analysis is used to elucidate how injection timing affects combustion by calculating mass fraction burn curves. It is observed that retarding injection timing retards combustion phasing, decreases peak cylinder pressure and temperature, and increases expansion pressure and temperature. Results show that insolubles and fuel-like hydrocarbons increase and oil-like hydrocarbons decrease with later injection timing. Analysis suggests that insolubles and fuel-like HC increase due to lower peak combustion temperature, while oil-like HC, which are distributed more widely throughout the cylinder, decrease due to higher expansion temperatures. The net result is that total PM mass increases with retarded combustion phasing, mostly due to increased insolubles. Considering the high fraction of insoluble PM (81–89%) at all injection timings tested at notch 5, steps taken to reduce PM elemental carbon should be the most effective path for future reductions in PM emissions. Further reductions in oil consumption may also reduce PM, but to a smaller extent.

Bore Polishing Wear in Diesel Engine Cylinders

Volume 1 ◽  
2004 ◽  
Author(s):  
Nagaraj Nayak ◽  
P. A. Lakshminarayanan ◽  
M. K. Gajendra Babu ◽  
A. D. Dani
Keyword(s):  
Cylinder Liner ◽  
Engine Oil ◽  
Cylinder Pressure ◽  
Oil Consumption ◽  
Depth Of Penetration ◽  
Wear Model ◽  
Carbon Particles ◽  
Peak Cylinder Pressure ◽  
Study Results

The rate of wear of the cylinder liner is mainly a function of peak cylinder pressure, the depth of penetration of hard carbon particles ingress during abusive running conditions. The problem of wear becomes severe as the blowby past the rings and the oil consumption of an engine increases in diesel engines. In this paper, a methodology is developed to estimate the wear of liner due to bore polishing action. The wear rate is correlated with the product of gaseous load, contact stress, and sliding action of the piston surfaces. Under abnormal conditions, the shear strain due to friction exceeds the plasticity limit of the material, superficial delamination occurs at the liner surfaces. The wear model was validated on large engines running on heavy fuel at 22-bar bmep. The case study results showed that by modifying the piston profile and liner geometry, and bore polishing of the liner surfaces is reduced and the engine oil consumption rate is improved substantially.

Exhaust Emissions Characterization of a Turbocharged 2-Stroke Tier 0+ Locomotive Engine: NOx, Particulate Matter and Soluble Organic Fraction Composition

2012 ◽  
Vol 134 (7) ◽  
Author(s):  
Stanislav V. Bohac ◽  
Eric Feiler ◽  
Ian Bradbury
Keyword(s):  
Particulate Matter ◽  
Elemental Carbon ◽  
Engine Oil ◽  
Exhaust Emission ◽  
Moderate Increase ◽  
Oil Consumption ◽  
Engine Operation ◽  
Soluble Organic Fraction ◽  
Insoluble Portion

This study presents a detailed exhaust emission characterization of a 2-Stroke turbocharged line haul locomotive diesel engine fitted with an early-development Tier 0 + emissions kit. The objective of this work is to use emissions characterization to gain insight into engine operation and mechanisms of pollutant formation for this family of engine, and identify areas of potential future engine emissions improvement. Results show that at the notches tested (notches 3–8) the largest contributor to particulate matter (PM)mass is insolubles (mostly elemental carbon), but that the soluble component of PM, comprising 14–32% of PM, is also significant. Gas chromatography (GC) analysis of the soluble portion shows that it is composed of 55–77% oil-like C22–C30+ hydrocarbons, with the remainder being fuel-like C9–C21 hydrocarbons. The emissions characterization suggests that advancing combustion timing should be effective in reducing PM mass by reducing the insoluble portion (elemental carbon) of PM at all notches. NOx will likely increase, but the current level of NOx is sufficiently below Tier 0+ limits to allow a moderate increase. Reducing engine oil consumption should also reduce PM mass at all notches, although to a smaller degree than measures that reduce the insoluble portion of PM.

scholarly journals Application of CFD, Taguchi Method, and ANOVA Technique to Optimize Combustion and Emissions in a Light Duty Diesel Engine

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Senlin Xiao ◽  
Wanchen Sun ◽  
Jiakun Du ◽  
Guoliang Li
Keyword(s):  
Diesel Engine ◽  
Taguchi Method ◽  
Fuel Consumption ◽  
Soot Formation ◽  
Dynamics Simulation ◽  
Injection Timing ◽  
Light Duty ◽  
Study Results ◽  
Main Injection ◽  
Pilot Fuel

Some previous research results have shown that EGR (exhaust gas recirculation) rate, pilot fuel quantity, and main injection timing closely associated with engine emissions and fuel consumption. In order to understand the combined effect of EGR rate, pilot fuel quantity, and main injection timing on theNOx(oxides of nitrogen), soot, and ISFC (indicated specific fuel consumption), in this study, CFD (computational fluid dynamics) simulation together with the Taguchi method and the ANOVA (analysis of variance) technique was applied as an effective research tool. At first, simulation model on combustion and emissions of a light duty diesel engine at original baseline condition was developed and the model was validated by test. At last, a confirmation experiment with the best combination of factors and levels was implemented. The study results indicated that EGR is the most influencing factor onNOx. In case of soot emission and ISFC, the greatest influence parameter is main injection timing. For all objectives, pilot fuel quantity is an insignificant factor. Furthermore, the engine with optimized combination reduces by at least 70% forNOx, 20% in soot formation, and 1% for ISFC, in contrast to original baseline engine.

scholarly journals Study of Using Oxygen-Enriched Combustion Air for Locomotive Diesel Engines

2000 ◽  
Vol 123 (1) ◽  
pp. 157-166 ◽  
Author(s):  
D. N. Assanis ◽  
R. B. Poola ◽  
R. Sekar ◽  
G. R. Cataldi
Keyword(s):  
Oxygen Content ◽  
Diesel Engines ◽  
Oxygen Enrichment ◽  
Air Separation ◽  
Injection Timing ◽  
Full Potential ◽  
Cylinder Pressure ◽  
Peak Cylinder Pressure ◽  
Locomotive Diesel ◽  
No Emissions

A thermodynamic simulation is used to study the effects of oxygen-enriched intake air on the performance and nitrogen oxide (NO) emissions of a locomotive diesel engine. The parasitic power of the air separation membrane required to supply the oxygen-enriched air is also estimated. For a given constraint on peak cylinder pressure, the gross and net power output of an engine operating under different levels of oxygen enrichment are compared with those obtained when a high-boost turbocharged engine is used. A 4 percent increase in peak cylinder pressure can result in an increase in net engine power of approximately 10 percent when intake air with an oxygen content of 28 percent by volume is used and fuel injection timing is retarded by 4 degrees. When the engine is turbocharged to a higher inlet boost, the same increase in peak cylinder pressure can improve power by only 4 percent. If part of the significantly higher exhaust enthalpies available as a result of oxygen enrichment is recovered, the power requirements of the air separator membrane can be met, resulting in substantial net power improvements. Oxygen enrichment with its attendant higher combustion temperatures, reduces emissions of particulates and visible smoke but increases NO emissions (by up to three times at 26 percent oxygen content). Therefore, exhaust gas after-treatment and heat recovery would be required if the full potential of oxygen enrichment for improving the performance of locomotive diesel engines is to be realized.

Abstract P065: Effects of Palm Oil Consumption on Blood Lipids: A Meta-Analysis of Clinical Trials

Circulation ◽  
2014 ◽  
Vol 129 (suppl_1) ◽  
Author(s):  
Ye Sun ◽  
Nithya Neelakantan ◽  
Yi Wu ◽  
Rob M van Dam
Keyword(s):  
Total Cholesterol ◽  
Vegetable Oils ◽  
Palm Oil ◽  
Ldl Cholesterol ◽  
Meta Analysis ◽  
Geographical Location ◽  
Hdl Cholesterol ◽  
Oil Consumption ◽  
Animal Fats ◽  
Study Results

Introduction: Palm oil is among the most commonly consumed cooking oils worldwide and, in contrast to most other vegetable oils, contains a high amount of saturated fatty acids. It has been suggested that palm oil has unique characteristics resulting in less detrimental effects on blood lipids than expected from its fat content. We therefore evaluated the effect of palm oil consumption on blood lipid concentrations as compared with vegetable oils high in natural unsaturated fatty acids, partially hydrogenated vegetable oils (rich in trans -fat), or animal fats. Methods: We searched PubMed, the Cochrane Library, Scopus, ProQuest, and Web of Science databases up to 31 October 2012 for trials of at least 2 weeks that compared the effects of palm oil consumption with at least one of the aforementioned comparison oils. Data on effects on total, LDL and HDL cholesterols and triglycerides were pooled using random effects meta-analysis. Results: A total of 25 studies were identified comparing palm oil with natural highly unsaturated vegetable oils. Palm oil significantly increased total cholesterol by 0.32 mmol/L (95% CI: 0.19, 0.44; I 2 =85.9%), increased LDL cholesterol by 0.20 mmol/L (95% CI: 0.09, 0.32; I 2 =82.9%), and increased HDL cholesterol by 0.02 mmol/L (95% CI: 0.01, 0.04; I 2 =56%) as compared with control oils. The considerable amount of heterogeneity in study results were partly explained by the type of control oil used, funding source, geographical location, and level of intake of test oil. Statistical tests suggested that this meta-analysis might be subject to publication bias. Eight studies were identified comparing palm oil with partially hydrogenated vegetable oils. When compared to trans -fat rich oils, palm oil significantly increased HDL cholesterol by 0.07 mmol/L (95% CI: 0.05, 0.09; I 2 =19.2%). However, palm oil did not significantly change total cholesterol (0.15 mmol/L, 95% CI: -0.04, 0.33), LDL cholesterol (0.11 mmol/L, 95% CI: -0.04, 0.27), or triglycerides (-0.02 mmol/L, 95% CI: -0.12, 0.07). Geographical location, method of preparation of test oils, and level of intake of trans -fat in control intervention were contributors to the heterogeneity in the study results. The pooled results from the 2 studies on comparison between palm oil and animal fats did not show a significant difference between the two dietary groups for total cholesterol (0.00 mmol/L, 95% CI: -0.08, 0.08), LDL cholesterol (-0.01 mmol/L, 95% CI: -0.08, 0.07), HDL cholesterol (0.00 mmol/L, 95% CI: -0.03, 0.04), or triglycerides (0.02 mmol/L, 95% CI: -0.15, 0.17). Conclusions: Palm oil consumption results in higher LDL cholesterol levels than other natural unsaturated vegetable oils. However, palm oil may be preferable to trans -fat rich oils based on its effect on HDL cholesterol. More studies are needed to evaluate the effects of palm oil consumption on incidence of coronary heart diseases.

A Numerical Simulation of Analysis of Backfiring Phenomena in a Hydrogen-Fueled Spark Ignition Engine

2016 ◽  
Vol 138 (10) ◽  
Author(s):  
K. A. Subramanian ◽  
B. L. Salvi
Keyword(s):  
Greenhouse Gas Emission ◽  
Hot Spot ◽  
Spark Ignition ◽  
Spark Ignition Engine ◽  
Intake Manifold ◽  
Injection Timing ◽  
Si Engine ◽  
Engine Operation ◽  
Study Results ◽  
Residual Gas

Hydrogen utilization in spark ignition (SI) engines could reduce urban pollution including particulate matter as well as greenhouse gas emission. However, backfiring, which is an undesirable combustion process of intake charge in hydrogen-fueled SI engine with manifold-based injection, is one of the major technical issues in view of safety of engine operation. Backfiring occurs generally during suction stroke as the hydrogen–air charge interacts with residual gas, resulting in flame growth and propagation toward upstream of engine's intake manifold, resulting in stalling of engine operation and high risk of safety. This work is aimed at analysis of backfiring in a hydrogen-fueled SI engine. The results indicate that backfiring is mainly function of residual gas temperature, start of hydrogen injection timing, and equivalence ratio. Any hot-spot present in the cylinder would act as ignition source resulting in more chances of backfiring. In addition to this, computational fluid dynamics (CFD) analysis was carried out in order to assess flow characteristics of hydrogen and air during suction stroke in intake manifold. Furthermore, numerical analysis of intake charge velocity, flame speed (deflagration), and flame propagation (backfiring) toward upstream of intake manifold was also carried out. Some notable points of backfiring control strategy including exhaust gas recirculation (EGR) and retarded (late) hydrogen injection timing are emerged from this study for minimizing chance of backfiring. This study results are useful for development of dedicated SI engine for hydrogen fuel in the aspects of elimination of backfiring.

Value of Travel Time for Public Transport Passenger in Urban and Intercity Trip

2016 ◽  
Vol 845 ◽  
pp. 408-415
Author(s):  
Amirotul M.H. Mahmudah ◽  
Djoko Sarwono ◽  
R.I. Pramesty ◽  
P.S. Rahina
Keyword(s):  
Travel Time ◽  
Low Income ◽  
Public Transport ◽  
Stated Preference ◽  
Multiple Linear Regression Model ◽  
Oil Consumption ◽  
The Public ◽  
Trip Purpose ◽  
Time Value ◽  
Study Results

Travel time value of public transport passengers is one of important variables in decision making about transport policy. Giving subsidy for public transport and allocate it to the right passenger will result in more benefits for the passenger of public transport. And as an effect it will increase the number of passengers then increase the public transport usage. As a result, it will reduce the number of private car usage which will reduce the air pollution and oil consumption and finally support sustainability transport. In this study, Travel time value based on questionnaire data, which is designed with stated preference with route choice approach. The multiple linear regression model is used to analyzed factors that influence public transport values of travel time, and traveler's income and trip purpose are introduced as categories. The study results indicate, in general, travel time value of regional trips is higher than urban travel. In Urban trip, travel time values for school is higher than values for work and other travels, while, for intercity travel, time value for work are higher than school and other travels. It can be comprehended since in this study the passenger of the urban trip who the travel purpose is work has low income. In common, when the personal income increase the travel time value also increase. But within this study, the public transport passengers who have no income consist of students, and their school regulations give hard punishment when their students come late. Based on that, the passenger with no income their travel time value is higher than the passengers have the lowest income.

Exhaust Emissions Characterization of a Turbocharged 2-Stroke Tier 0+ Locomotive Engine: NOx, PM, SOF and SOF Composition

2011 ◽  
Author(s):  
Stanislav V. Bohac ◽  
Eric Feiler ◽  
Ian Bradbury
Keyword(s):  
Elemental Carbon ◽  
Engine Oil ◽  
Exhaust Emission ◽  
Moderate Increase ◽  
Oil Consumption ◽  
Engine Emissions ◽  
Engine Operation ◽  
Locomotive Engine ◽  
Insoluble Portion

This study presents a detailed exhaust emission characterization of an EMD 2-Stroke turbocharged line haul locomotive diesel engine fitted with an early-development Tier 0+ emissions kit. The objective of this work is to use emissions characterization to gain insight into engine operation and mechanisms of pollutant formation for this family of engine, and identify areas of potential future engine emissions improvement. Results show that at the notches tested (notches 3–8) the largest contributor to PM mass is insolubles (mostly elemental carbon), but that the soluble component of PM, comprising 14–32% of PM, is also significant. GC-FID analysis of the soluble portion shows that it is composed of 55–77% oil-like C22-C30+ hydrocarbons, with the remainder being fuel-like C9-C21 hydrocarbons. The emissions characterization suggests that advancing combustion timing should be effective in reducing PM mass by reducing the insoluble portion (elemental carbon) of PM at all notches. NOx will likely increase, but the current level of NOx is sufficiently below Tier 0+ limits to allow a moderate increase. Reducing engine oil consumption should also reduce PM mass at all notches, although to a smaller degree than measures that reduce the insoluble portion of PM.

Performance and heat release analysis of a pilot-ignited natural gas engine

2002 ◽  
Vol 3 (3) ◽  
pp. 171-184 ◽  
Author(s):  
S. R. Krishnan ◽  
M Biruduganti ◽  
Y Mo ◽  
S. R. Bell ◽  
K. C. Midkiff
Keyword(s):  
Natural Gas ◽  
Heat Release ◽  
Specific Energy Consumption ◽  
Intake Manifold ◽  
Dual Fuel ◽  
Injection Timing ◽  
Compression Ignition Engine ◽  
Engine Operation ◽  
Operating Variables ◽  
Release Analysis

The influence of engine operating variables on the performance, emissions and heat release in a compression ignition engine operating in normal diesel and dual-fuel modes (with natural gas fuelling) was investigated. Substantial reductions in NOx emissions were obtained with dual-fuel engine operation. There was a corresponding increase in unburned hydrocarbon emissions as the substitution of natural gas was increased. Brake specific energy consumption decreased with natural gas substitution at high loads but increased at low loads. Experimental results at fixed pilot injection timing have also established the importance of intake manifold pressure and temperature in improving dual-fuel performance and emissions at part load.

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