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.

Soot Evolution With Cyclic Crank-Angle-Resolved Two-Color Thermometry in an Optical Diesel Engine Fueled With Biodiesel Blend and ULSD

2012 ◽  
Vol 134 (9) ◽  
Author(s):  
Kan Zha ◽  
Radu-Catalin Florea ◽  
Marcis Jansons
Keyword(s):  
Diesel Engine ◽  
High Speed ◽  
Soot Formation ◽  
Soot Temperature ◽  
Soot Emission ◽  
Piston Bowl ◽  
Crank Angle ◽  
Wall Impingement ◽  
Kl Factor ◽  
Biodiesel Blend

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 spray 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 late-cycle soot emissions. For both fuels, higher fuel injection pressure led to lower late-cycle soot KL levels. 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.

Effect of Biodiesel, JP-8 and Ultra Low Sulfur Diesel Fuel on Autoignition, Combustion, Performance and Emissions in a Single Cylinder Diesel Engine

2010 ◽  
Author(s):  
Chandrasekharan Jayakumar ◽  
Jagdish Nargunde ◽  
Anubhav Sinha ◽  
Walter Bryzik ◽  
Naeim A. Henein ◽  
...  
Keyword(s):  
Diesel Engine ◽  
Fuel Properties ◽  
Nox Emissions ◽  
Single Cylinder ◽  
Combustion Performance ◽  
Ultra Low Sulfur Diesel ◽  
Diffusion Controlled ◽  
Performance And Emissions ◽  
Combustion Fraction ◽  
Low Sulfur

Concern about the depletion of petroleum reserves, rising prices of conventional fuels, security of supply and global warming have driven research toward the development of renewable fuels for use in diesel engines. These fuels have different physical and chemical properties that affect the diesel combustion process. This paper compares between the autoignition, combustion, performance and emissions of soybean derived biodiesel, JP-8 and ultra low sulfur diesel (ULSD) in a high speed single-cylinder research diesel engine equipped with a common rail injection system. Tests were conducted at steady state conditions at different injection pressures ranging from 600 bar to 1200 bar. The ‘rate of heat release’ traces are analyzed to determine the effect of fuel properties on the ignition delay, premixed combustion fraction and mixing and diffusion controlled combustion fractions. Biodiesel produced the largest diffusion controlled combustion fraction at all injection pressures compared to ULSD and JP-8. At 600 bar injection pressure, the diffusion controlled combustion fraction for biodiesel was 53% whereas both JP-8 and ULSD produced 39%. In addition, the effect of fuel properties on engine performance, fuel economy, and engine-out emissions is determined. On an average JP-8 produced 3% higher thermal efficiency than ULSD. Special attention is given to the NOx emissions and particulate matter characteristics. On an average biodiesel produced 37% less NOx emissions compared to ULSD and JP-8.

Modelling and CFD Simulation of Effects of Spray Penetration on Piston Bowl Impingement in a DI Diesel Engine for Biodiesel-Diesel Blend (B20)

2012 ◽  
Author(s):  
Subhash Lahane ◽  
K. A. Subramanian
Keyword(s):  
Diesel Engine ◽  
Cfd Simulation ◽  
Injection Pressure ◽  
Spray Penetration ◽  
Penetration Distance ◽  
Piston Bowl ◽  
Fuel Jet ◽  
Wall Impingement ◽  
Di Diesel Engine ◽  
Nozzle Hole

The effect of spray penetration distance on fuel impingement on piston bowl of a 7.4 kW diesel engine for biodiesel-diesel blend (B20) was studied using modeling and CFD simulation. As the peak inline fuel pressure increased from 460 bar with base diesel to 480 bar with B20, the spray penetration distance (fuel jet) increases. It is observed from the study that the jet tip hits on piston bowl resulting to fuel impingement which is one of durability issues for use of biodiesel blend in the diesel engine. In addition to this, the simulation of effects of different injection pressures up to 2000 bar on spray penetration distance and wall impingement were also studied. The penetration distance increases with increase the in-line fuel pressure and it decreases with decrease nozzle hole diameter. The fuel impingement on piston bowl of the engine with high injection pressure (typically 1800 bar) can be avoided by decreasing the nozzle diameter from 0.19 mm to 0.1 mm. Increase in swirl ratio could also reduce fuel impingement problem.

Effects of Fuel Quantity on Soot Formation Process for Biomass-Based Renewable Diesel Fuel Combustion

2016 ◽  
Author(s):  
Wei Jing ◽  
Zengyang Wu ◽  
William L. Roberts ◽  
Tiegang Fang
Keyword(s):  
Diesel Fuel ◽  
Formation Process ◽  
Fuel Injection ◽  
Soot Formation ◽  
Injection Pressure ◽  
Soot Temperature ◽  
Renewable Diesel ◽  
Constant Volume Combustion Chamber ◽  
Kl Factor ◽  
Soot Measurement

Soot formation process was investigated for biomass-based renewable diesel fuel, such as biomass to liquid (BTL), and conventional diesel combustion under varied fuel quantities injected into a constant volume combustion chamber. Soot measurement was implemented by two-color pyrometry under quiescent type diesel engine conditions (1000 K and 21% O2 concentration). Different fuel quantities, which correspond to different injection widths from 0.5 ms to 2 ms under constant injection pressure (1000 bar), were used to simulate different loads in engines. For a given fuel, soot temperature and KL factor show a different trend at initial stage for different fuel quantities, where a higher soot temperature can be found in a small fuel quantity case but a higher KL factor is observed in a large fuel quantity case generally. Another difference occurs at the end of combustion due to the termination of fuel injection. Additionally, BTL flame has a lower soot temperature, especially under a larger fuel quantity (2 ms injection width). Meanwhile, average soot level is lower for BTL flame, especially under a lower fuel quantity (0.5 ms injection width). BTL shows an overall low sooting behavior with low soot temperature compared to diesel, however, trade-off between soot level and soot temperature needs to be carefully selected when different loads are used.

Effects of B20 on Combustion, Emissions and Performance of a Light-Duty Diesel Engine

2009 ◽  
Author(s):  
Amy M. Peterson ◽  
Po-I Lee ◽  
Ming-Chia Lai ◽  
Ming-Cheng Wu ◽  
Craig L. DiMaggio
Keyword(s):  
Diesel Engine ◽  
High Speed ◽  
Combustion Noise ◽  
Low Temperature Combustion ◽  
Performance And Emission ◽  
Ultra Low Sulfur Diesel ◽  
White Grease ◽  
Light Duty ◽  
Di Diesel Engine ◽  
And Performance

This paper compares 20% bio-diesel (B20-choice white grease) fuel with baseline ultra low sulfur diesel (ULSD) fuel on the performance of combustion and emissions of a light-duty 4-cylinder 2.8-liter common-rail DI diesel engine. The results show that operating the engine in the Low Temperature Combustion (LTC) regime produces lower PM and NOx with a slight penalty in fuel consumption, THC, and CO emissions. B20, in general, produces less soot. A slight increase in NOx emissions is shown with B20 compared to ULSD, with an exception at the high speed point where B20 has lower NOx values. In addition, the performance and emission characteristics are investigated as a function of the ECU injection strategy. The addition of pilot injections is found to effectively reduce combustion noise and extends the injection retard window to reach LTC combustion regimes with acceptable noise level for LD diesel engines.

Effect of ultra-low sulfur diesel quality on exhaust emission in euro vi diesel engine

2019 ◽  
Author(s):  
Helineia Oliveira Gomes ◽  
Tadeu Cavalcante Cordeiro Melo ◽  
Marcia Figueiredo Moreira
Keyword(s):  
Diesel Engine ◽  
Exhaust Emission ◽  
Ultra Low Sulfur Diesel ◽  
Low Sulfur
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