Exhaust-Stream and In-Cylinder Measurements and Analysis of the Soot Emissions From a Common Rail Diesel Engine Using Two Fuels

2009 ◽  
Author(s):  
Patrick Kirchen ◽  
Konstantinos Boulouchos ◽  
Peter Obrecht ◽  
Andrea Bertola
Keyword(s):  
Diesel Engine ◽  
Soot Formation ◽  
Cetane Number ◽  
Combustion Process ◽  
Premixed Combustion ◽  
Aromatic Content ◽  
Kl Factor ◽  
Exhaust Stream ◽  
Soot Emissions ◽  
Operating Points

The operation and emissions of a four cylinder, passenger car common-rail diesel engine operating with two different fuels was investigated on the basis of exhaust stream and in-cylinder soot measurements, as well as a thermodynamic analysis of the combustion process. The two fuels considered were a standard diesel fuel and a synthetic diesel (fuel two) with a lower aromatic content, evaporation temperature, and cetane number than the standard diesel. The exhaust stream soot emissions, measured using an FSN system, as well as a photo-acoustic soot sensor (AVL Micro Soot Sensor), were lower with the second fuel throughout the entire engine operating map. To elucidate the cause of the reduced exhaust stream soot emissions, the in-cylinder soot temperature and KL factor (proportional to concentration) were measured using miniature, three color pyrometers mounted in the glow plug bores. Using the maximum KL factor value to quantify the soot formation process, it was seen that for all operating points, less soot was formed in the combustion chamber using the second fuel. The oxidation of the soot, however, was not strongly influenced by the fuel, as the relative oxidized soot fraction was not significantly different for the two fuels. The reduced soot formation of fuel two was attributed to the lower aromatic content of the fuel. The soot cloud temperatures for operation with the two fuels were not seen differ significantly. Similar correlations between the cylinder-out soot emissions, characterized using the pyrometers, and the exhaust stream soot emissions were seen for both fuels. The combustion process itself, was only seen to differ between the two fuels to a much lesser degree than the soot formation process. The predominant differences were seen as higher maximum fuel conversion rates during premixed combustion at several operating points, when fuel two was used. This was attributed to the lower evaporation temperatures and longer ignition delays (characterized by the lower cetane number) leading to larger premixed combustion fractions.

Exhaust-Stream and In-Cylinder Measurements and Analysis of the Soot Emissions From a Common Rail Diesel Engine Using Two Fuels

2010 ◽  
Vol 132 (11) ◽  
Author(s):  
Patrick Kirchen ◽  
Peter Obrecht ◽  
Konstantinos Boulouchos ◽  
Andrea Bertola
Keyword(s):  
Diesel Engine ◽  
Soot Formation ◽  
Cetane Number ◽  
Combustion Process ◽  
Premixed Combustion ◽  
Aromatic Content ◽  
Kl Factor ◽  
Exhaust Stream ◽  
Soot Emissions ◽  
Operating Points

The operation and emissions of a four cylinder, passenger car common-rail diesel engine operating with two different fuels was investigated on the basis of exhaust-stream and in-cylinder soot measurements, as well as a thermodynamic analysis of the combustion process. The two fuels considered were a standard diesel fuel and a synthetic diesel (fuel two) with a lower aromatic content, evaporation temperature, and cetane number than the standard diesel. The exhaust-stream soot emissions, measured using a filter smoke number system, as well as a photo-acoustic soot sensor (AVL Micro Soot Sensor), were lower with the second fuel throughout the entire engine operating map. To elucidate the cause of the reduced exhaust-stream soot emissions, the in-cylinder soot temperature and the KL factor (proportional to concentration) were measured using miniature, three-color pyrometers mounted in the glow plug bores. Using the maximum KL factor value to quantify the soot formation process, it was seen that for all operating points, less soot was formed in the combustion chamber using the second fuel. The oxidation of the soot, however, was not strongly influenced by the fuel, as the relative oxidized soot fraction was not significantly different for the two fuels. The reduced soot formation of fuel two was attributed to the lower aromatic content of the fuel. The soot cloud temperatures for operation with the two fuels were not seen differ significantly. Similar correlations between the cylinder-out soot emissions, characterized using the pyrometers, and the exhaust-stream soot emissions were seen for both fuels. The combustion process itself was only seen to differ between the two fuels to a much lesser degree than the soot formation process. The predominant differences were seen as higher maximum fuel conversion rates during premixed combustion at several operating points, when fuel two was used. This was attributed to the lower evaporation temperatures and longer ignition delays (characterized by the lower cetane number) leading to larger premixed combustion fractions.

scholarly journals An Improved Soot Formation Model for 3D Diesel Engine Simulations

2006 ◽  
Vol 129 (3) ◽  
pp. 877-884 ◽  
Author(s):  
Joan Boulanger ◽  
Fengshan Liu ◽  
W. Stuart Neill ◽  
Gregory J. Smallwood
Keyword(s):  
Diesel Engine ◽  
Soot Formation ◽  
Computing Time ◽  
Combustion Process ◽  
Computational Cost ◽  
Wall Region ◽  
Soot Particles ◽  
Engine Combustion ◽  
Near Wall ◽  
Soot Model

Soot formation phenomenon is far from being fully understood today and models available for simulation of soot in practical combustion devices remain of relatively limited success, despite significant progresses made over the last decade. The extremely high demand of computing time of detailed soot models make them unrealistic for simulation of multidimensional, transient, and turbulent diesel engine combustion. Hence, most of the investigations conducted in real configuration such as multidimensional diesel engines simulation utilize coarse modeling, the advantages of which are an easy implementation and low computational cost. In this study, a phenomenological three-equation soot model was developed for modeling soot formation in diesel engine combustion based on considerations of acceptable computational demand and a qualitative description of the main features of the physics of soot formation. The model was developed based on that of Tesner et al. and was implemented into the commercial STAR-CD™ CFD package. Application of this model was demonstrated in the modeling of soot formation in a single-cylinder research version of Caterpillar 3400 series diesel engine with exhaust gas recirculation (EGR). Numerical results show that the new soot formulation overcomes most of the drawbacks in the existing soot models dedicated to this kind of engineering task and demonstrates a robust and consistent behavior with experimental observation. Compared to the existing soot models for engine combustion modeling, some distinct features of the new soot model include: no soot is formed at low temperature, minimal model parameter adjustment for application to different fuels, and there is no need to prescribe the soot particle size. At the end of expansion, soot is predicted to exist in two separate regions in the cylinder: in the near wall region and in the center part of the cylinder. The existence of soot in the near wall region is a result of reduced soot oxidation rate through heat loss. They are the source of the biggest primary particles released at the end of the combustion process. The center part of the cylinder is populated by smaller soot particles, which are created since the early stages of the combustion process but also subject to intense oxidation. The qualitative effect of EGR is to increase the size of soot particles as well as their number density. This is linked to the lower in-cylinder temperature and a reduced amount of air.

scholarly journals COMBUSTION ANALYSIS OF D-LIMONENE AS AN ADDITIVE TO DIESEL-BIODIESEL BLENDS IN COMPRESSION IGNITION ENGINES

2019 ◽  
Vol 18 (2) ◽  
pp. 03
Author(s):  
L. F. Micheli ◽  
L. E. R. Pereira ◽  
D. L. Módolo ◽  
W. K. D. C. Saruhashi
Keyword(s):  
Diesel Engine ◽  
Vegetable Oils ◽  
Cetane Number ◽  
Combustion Process ◽  
Orange Peel ◽  
Diesel Oil ◽  
Biodiesel Blends ◽  
Positive Effects ◽  
Lubricant Oil ◽  
Compression Ignition Engines

Vegetable oils, when subjected to transesterification process generate “vegetable oils esters”, with similar properties as density, cetane number, heating values, air-fuel ratio. However, problems resulting from the higher viscosity, leads to a worst spraying and combustion, formation of undesirable deposits on engine parts and contamination of the lubricant oil. Due to these problems, it is interesting to study an additive, also derived from biomass, to improve the characteristics of biodiesel for a suitable use in diesel engines. This paper proposes an additive (d-limonene obtained from orange peel) and preliminary results obtained from the tests in a stationary diesel engine fueled with mixtures of diesel/biodiesel/d-limonene, in different concentration to compare with a regular diesel-biodiesel blend and analyzes the influence of the additive on the combustion process. The diesel oil used was purchased from BR supply network (containing 7% biodiesel in its composition) and two blends with different concentrations of the additive (1% and 3% of d-limonene) were prepared and tested. Diesel without additive was also tested. The effects of the DS10 addititivation with d-limonene in the combustion process of a diesel engine have been analyzed, the results obtained were satisfactory showing the positive effects in the combustion process with the addition of d-limonene in diesel-biodiesel blends, decreasing the ignition delay around 2 degrees and showing an improvement in the cetane number of the fuel.

Experimental Study of Coal Liquefaction Diesel Combustion and Emissions

2013 ◽  
Vol 291-294 ◽  
pp. 1914-1919
Author(s):  
Yu Li Dai ◽  
Yi Qiang Pei ◽  
Jing Qin ◽  
Jian Ye Zhang ◽  
Yun Long Li
Keyword(s):  
Experimental Study ◽  
Heat Release ◽  
Ignition Delay ◽  
Cetane Number ◽  
Combustion Process ◽  
Load Condition ◽  
Coal Liquefaction ◽  
Soot Emissions ◽  
Co Emission ◽  
Load Conditions

An experimental study was conducted on the combustion processes and emissions of direct coal liquefaction (DDCL) and Fischer-Tropsch (FT) fuels in a single-cylinder research diesel engine. Under low load conditions (5 bar IMEP), the results show that the ignition delay is shorter for the FT fuel compared with the reference fuel (Euro IV diesel), while it is longer for the DDCL fuel compared with the reference fuel. However, under high load conditions (10-15 bar IMEP), the Cetane number (CN) shows insignificant effects on the combustion process. The premixed heat release peaks of the fuels are correlated with the ignition delays, i.e. shorter ignition delay led to lower premixed heat release peak. For the emissions, both the FT fuel and the DDCL fuel show similar NOx level to the reference fuel under the conditions tested. The two liquefaction fuels show significantly lower soot emissions than the reference fuel, specifically for the higher load conditions (>=10bar IMEP), and the FT fuel produced the lowest level of soot emissions among the three fuels. For the FT and DDCL fuels, the HC emissions are generally lower than those of the reference fuel, except for the lowest load condition, which DDCL produces slightly higher HC emission. However, the CO emission of FT is lower than the reference fuel while the CO emission of DDCL is higher. In terms of unregulated emissions, the two liquefaction fuels show insignificant difference compared with the reference fuel at very low levels.

Comparison of Soot Evolution Using High-Speed CMOS Color Camera and Two-Color Thermometry in an Optical Diesel Engine Fueled With B20 Biodiesel Blend and Ultra-Low Sulfur Diesel

2011 ◽  
Author(s):  
Kan Zha ◽  
Radu-Catalin Florea ◽  
Marcis Jansons
Keyword(s):  
Diesel Engine ◽  
High Speed ◽  
Soot Formation ◽  
Soot Temperature ◽  
Piston Bowl ◽  
Ultra Low Sulfur Diesel ◽  
Wall Impingement ◽  
Kl Factor ◽  
Biodiesel Blend ◽  
Low Sulfur

Biodiesel is a desirable alternative fuel for the diesel engine due to its low engine-out soot emission tendency. When blended with petroleum-based diesel fuels, soot emissions generally decrease in proportion to the volume fraction of biodiesel in the mixture. While comparisons of engine-out soot measurements between biodiesel blends and petroleum-based diesel have been widely reported, in-cylinder soot evolution has not been experimentally explored to the same extent. To elucidate the soot emission reduction mechanism of biodiesel, a single-cylinder optically-accessible diesel engine was used to compare the in-cylinder soot evolution when fueled with ultra-low sulfur diesel (ULSD) to that using a B20 biodiesel blend (20% vol/vol biodiesel ASTM D6751-03A). Soot temperature and KL factors are simultaneously determined using a novel two-color optical thermometry technique implemented with a high-speed CMOS color camera having wide-band Bayer filters. The crank-angle resolved data allows quantitative comparison of the rate of in-cylinder soot formation. High-speed spray images show that B20 has more splashing during spray wall impingement than ULSD, distributing rebounding fuel droplets over a thicker annular ring interior to the piston bowl periphery. The subsequent soot luminescence is observed by high-speed combustion imaging and soot temperature and KL factor measurements. B20 forms soot both at low KL magnitudes over large areas between fuel jets, and at high values among remnants of the fuel spray, along its axis and away from the bowl edge. In contrast, ULSD soot luminescence is observed exclusively as pool burning on the piston bowl surfaces resulting from fuel wall impingement. The soot KL factor evolution during B20 combustion indicates earlier and significantly greater soot formation than with ULSD. B20 combustion is also observed to have a greater soot oxidation rate which results in lower engine-out soot emissions. Measured soot temperatures near 1875K were similar for the two fuels for the duration of combustion. For both fuels, higher fuel injection pressure led to lower late-cycle soot KL levels. The trends of soot natural luminosity correlated well with the trends of soot KL factor, suggesting that relatively simple measurements of combustion luminosity may provide somewhat quantitative information about in-cylinder soot formation and oxidation. The apparent rate of heat release (ARHR) analysis under steady skip-fire conditions indicates that B20 combustion is less sensitive to wall temperature than that observed with ULSD due to a lesser degree of pool burning. B20 was found to have both a shorter ignition delay and shorter combustion duration than ULSD.

Fuel Property Effects on PCCI Combustion in a Heavy-Duty Diesel Engine

2012 ◽  
Vol 134 (5) ◽  
Author(s):  
Cosmin E. Dumitrescu ◽  
W. Stuart Neill ◽  
Hongsheng Guo ◽  
Vahid Hosseini ◽  
Wallace L. Chippior
Keyword(s):  
Diesel Engine ◽  
Fuel Injection ◽  
Cetane Number ◽  
Injection System ◽  
Injection Timing ◽  
Heavy Duty ◽  
Fuel Property ◽  
Heavy Duty Diesel Engine ◽  
Soot Emissions ◽  
Heavy Duty Diesel

An experimental study was performed to investigate fuel property effects on premixed charge compression ignition (PCCI) combustion in a heavy-duty diesel engine. A matrix of research diesel fuels designed by the Coordinating Research Council, referred to as the Fuels for Advanced Combustion Engines (FACE), was used. The fuel matrix design covers a wide range of cetane numbers (30 to 55), 90% distillation temperatures (270 to 340 °C) and aromatics content (20 to 45%). The fuels were tested in a single-cylinder Caterpillar diesel engine equipped with a common-rail fuel injection system. The engine was operated at 900 rpm, a relative air/fuel ratio of 1.2 and 60% exhaust gas recirculation (EGR) for all fuels. The study was limited to a single fuel injection event starting between −30° and 0 °CA after top dead center (aTDC) with a rail pressure of 150 MPa. The brake mean effective pressure (BMEP) ranged from 2.6 to 3.1 bar depending on the fuel and its injection timing. The experimental results show that cetane number was the most important fuel property affecting PCCI combustion behavior. The low cetane number fuels had better brake specific fuel consumption (BSFC) due to more optimized combustion phasing and shorter combustion duration. They also had a longer ignition delay period available for premixing, which led to near-zero soot emissions. The two fuels with high cetane number and high 90% distillation temperature produced significant soot emissions. The two fuels with high cetane number and high aromatics produced the highest brake specific NOx emissions, although the absolute values were below 0.1 g/kW-h. Brake specific HC and CO emissions were primarily a function of the combustion phasing, but the low cetane number fuels had slightly higher HC and lower CO emissions than the high cetane number fuels.

scholarly journals Spray, Combustion, and Air Pollutant Characteristics of JP-5 for Naval Aircraft from Experimental Single-Cylinder CRDI Diesel Engine

Energies ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2362
Author(s):  
Hyungmin Lee
Keyword(s):  
Diesel Engine ◽  
Ignition Delay ◽  
Fuel Injection ◽  
Cetane Number ◽  
Combustion Process ◽  
Air Pollutant ◽  
Spray Combustion ◽  
Injection Timing ◽  
Visualization System ◽  
Single Cylinder

This study was performed to analyze the spray, combustion, and air pollutant characteristic of JP-5 fuel for naval aircraft in a spray visualization system and a single-cylinder CRDI diesel engine that can be visualized. The analysis results of JP-5 fuel were compared with DF. The spray tip penetration of JP-5 showed diminished results as the spray developed. JP-5 had the highest ROHR and ROPR regardless of the fuel injection timings. The physicochemical characteristics of JP-5, such as its excellent vaporization and low cetane number, were analyzed to prolong the ignition delay. Overall, the longer combustion period and the lower heat loss of the DF raised the engine torque and the IMEP. JP-5 showed higher O2 and lower CO2 levels than the DF fuel. The CO emission level increased as the injection timing was advanced in two test fuels, and the CO emitted from the DF fuel, which has a longer combustion period than JP-5, turned out to be lower. NOx also reduced as the fuel injection timing was retarded, but it was discharged at a higher level in JP-5 due to the large heat release. The images from the combustion process visualization showed that the flame luminosity of DF is stronger, its ignition delay is shorter, and its combustion period is longer than that of JP-5.

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