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

Author(s):  
Wei Jing ◽  
Zengyang Wu ◽  
William L. Roberts ◽  
Tiegang Fang

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.

Author(s):  
Wei Jing ◽  
Zengyang Wu ◽  
William L. Roberts ◽  
Tiegang Fang

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.


Energies ◽  
2019 ◽  
Vol 12 (20) ◽  
pp. 3837 ◽  
Author(s):  
Sam Ki Yoon ◽  
Jun Cong Ge ◽  
Nag Jung Choi

This experiment investigates the combustion and emissions characteristics of a common rail direct injection (CRDI) diesel engine using various blends of pure diesel fuel and palm biodiesel. Fuel injection pressures of 45 and 65 MPa were investigated under engine loads of 50 and 100 Nm. The fuels studied herein were pure diesel fuel 100 vol.% with 0 vol.% of palm biodiesel (PBD0), pure diesel fuel 80 vol.% blended with 20 vol.% of palm biodiesel (PBD20), and pure diesel fuel 50 vol.% blended with 50 vol.% of palm biodiesel (PBD50). As the fuel injection pressure increased from 45 to 65 MPa under all engine loads, the combustion pressure and heat release rate also increased. The indicated mean effective pressure (IMEP) increased with an increase of the fuel injection pressure. In addition, for 50 Nm of the engine load, an increase to the fuel injection pressure resulted in a reduction of the brake specific fuel consumption (BSFC) by an average of 2.43%. In comparison, for an engine load of 100 Nm, an increase in the fuel injection pressure decreased BSFC by an average of 0.8%. Hydrocarbon (HC) and particulate matter (PM) decreased as fuel pressure increased, independent of the engine load. Increasing fuel injection pressure for 50 Nm engine load using PBD0, PBD20 and PBD50 decreased carbon monoxide (CO) emissions. When the fuel injection pressure was increased from 45 MPa to 65 MPa, oxides of nitrogen (NOx) emissions were increased for both engine loads. For a given fuel injection pressure, NOx emissions increased slightly as the biodiesel content in the fuel blend increased.


2016 ◽  
Vol 2016 (0) ◽  
pp. G0700102
Author(s):  
Shun SHIMOTSUMAGARI ◽  
Takeru IWAMOTO ◽  
Masaoki SUGIHARA ◽  
Hideki HASHIMOTO ◽  
Osamu MORIUE

1991 ◽  
Author(s):  
Haruyuki Yokota ◽  
Takeyuki Kamimoto ◽  
Hidenori Kosaka ◽  
Kinji Tsujimura

2012 ◽  
Vol 4 (4) ◽  
pp. 381-385
Author(s):  
Birutė Skukauskaitė ◽  
Tomas Mickevičius

The purpose of this research was to examine penetration peculiarities of rapeseed oil injected into the combustion chamber of a diesel engine. For conducting tests, a stand imitating conditions (air density) for the engine combustion chamber was designed. The analysis of pictures obtained using a fast recording camera determined fuel injection into the chamber volume and calculated the velocity of spray head. It was established that fuel spray of injected rapeseed oil proceeds deeper into the combustion chamber than that of mineral diesel fuel. The parameters of fuel spray are mainly influenced by injection pressure rather than by the density of compressed gases. Santrauka Šio darbo tikslas buvo ištirti į dyzelinio variklio degimo kamerą įpurškiamos rapsų aliejaus čiurkšlės kitimo ypatumus, lyginant su mineraliniu dyzelinu. Tyrimams sukonstruotas stendas, kuriame buvo imituojamos sąlygos (oro tankis), esančios variklio degimo kameroje. Analizuojant spartaus filmavimo vaizdo kamera gautus vaizdus, buvo išmatuotas degalų čiurkšlės įsiskverbimo į degimo kamerą dydis, apskaičiuotas čiurkšlės fronto judėjimo greitis. Nustatyta, kad įpurškiamo rapsų aliejaus čiurkšlė į degimo kamerą įsiskverbia giliau, negu mineralinio dyzelino čiurkšlė. Įpurškiamų degalų čiurkšlės parametrams didesnės įtakos turi įpurškimo slėgis nei aplinkos dujų tankis.


Author(s):  
Jim Cowart ◽  
Dianne Luning Prak ◽  
Len Hamilton

In an effort to understand the effects of injection system pressure on alternative fuel performance, a single cylinder diesel engine was outfit with a modern common rail fuel injection system and piezoelectric injector. As future new fuels will likely be used in both older mechanical injected engines as well as newer high pressure common rail engines, the question as to the sensitivity of a new fuel type across a range of engines is of concern. In this study conventional diesel fuel (Navy NATO F76) was compared with the new Navy HRD (Hydro-processed Renewable Diesel) fuel from algal sources, as well as the high cetane reference fuel nC16 (n-hexadecane CN=100). It was seen that in general, IGD (Ignition Delay) was shortened for all fuels with increasing fuel injection pressure, and was shortened with higher CN fuels. The combustion duration for all fuels was also significantly reduced with increasing fuel injection pressure, however, longer durations were seen for higher CN fuels at the same fuel pressure due to less pre-mixing before the start of combustion. Companion modeling using the LLNL (Lawrence Livermore National Lab) heavy hydro-carbon and diesel PRF chemical kinetic mechanisms for HRD and nC16 was applied to understand the relative importance of the physical and chemical delay periods of the IGD. It was seen that at low fuel injection pressures, the physical and chemical delay times are of comparable duration. However, as injection pressure increases the importance of the chemical delay times increases significantly (longer), especially with the lower CN fuel.


Author(s):  
Kan Zha ◽  
Radu-Catalin Florea ◽  
Marcis Jansons

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.


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