The effect of fuel aromatic content and cetane number on combustion in a UAV diesel engine

Author(s):  
Michael T. Szedlmayer ◽  
Kenneth Kim ◽  
Chol-Bum Kweon ◽  
Kurt Kruger
Author(s):  
Patrick Kirchen ◽  
Peter Obrecht ◽  
Konstantinos Boulouchos ◽  
Andrea Bertola

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.


Author(s):  
Patrick Kirchen ◽  
Konstantinos Boulouchos ◽  
Peter Obrecht ◽  
Andrea Bertola

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.


2018 ◽  
Vol 4 (2) ◽  
Author(s):  
Soni S. Wirawan dkk

Biodiesel is a viable substitute for petroleum-based diesel fuel. Its advantages are improved lubricity, higher cetane number and cleaner emission. Biodiesel and its blends with petroleum-based diesel fuel can be used in diesel engines without any signifi cant modifi cations to the engines. Data from the numerous research reports and test programs showed that as the percent of biodiesel in blends increases, emission of hydrocarbons (HC), carbon monoxide (CO), and particulate matter (PM) all decrease, but the amount of oxides of nitrogen (NOx) and fuel consumption is tend to increase. The most signifi cant hurdle for broader commercialization of biodiesel is its cost. In current fuel price policy in Indonesia (especially fuel for transportation), the higher percent of biodiesel in blend will increase the price of blends fuel. The objective of this study is to assess the optimum blends of biodiesel with petroleum-based diesel fuel from the technically and economically consideration. The study result recommends that 20% biodiesel blend with 80% petroleum-based diesel fuel (B20) is the optimum blend for unmodifi ed diesel engine uses.Keywords: biodiesel, emission, optimum, blend


2014 ◽  
Author(s):  
XiaoDan Cui ◽  
Peng Lu ◽  
Hiroki Nakamura ◽  
Mitsuhiro Matsunaga ◽  
Akira Kikusato ◽  
...  

2014 ◽  
Vol 592-594 ◽  
pp. 1632-1637
Author(s):  
Ramalingam Senthil ◽  
C. Paramasivam ◽  
Rajendran Silambarasan

Nerium methyl ester, an esterified biofuel, has an excellent cetane number and a reasonable calorific value. It closely resembles the behaviour of diesel. However, being a fuel of different origin, the standard design limits of a diesel engine is not suitable for Nerium methyl ester (NME). Therefore, in this work, a set of design and operational parameters are studied to find out the optimum performance of Nerium methyl ester run diesel engine. This work targets at finding the effects of the engine design parameter viz. fuel injection pressure (IP) on the performance with regard to specific fuel consumption (SFC), brake thermal efficiency (BTHE) and emissions of CO, CO2, HC, NOxwith N20 as fuel. Comparison of performance and emission was done for different values of injection pressure to find best possible condition for operating engine with NME. For small sized direct injection constant speed engines used for agricultural applications, the optimum injection pressure was found as 240bar.Methyl esters from Nerium, with properties close to diesel; show better performance and emission characteristics. Hence Nerium (N20) blend can be used in existing diesel engines without compromising the engine performance. Diesel (25%) thus saved will greatly help the interests of railways in meeting the demand for fuel,as diesel trains are operated at maximum load condition.


2012 ◽  
Vol 512-515 ◽  
pp. 1888-1891
Author(s):  
Jia Yi Du ◽  
Wei Xun Zhang ◽  
Deng Pan Zhang ◽  
Zhen Yu Sun

The influence of cetane number improver on emission characteristics of diesel engine fueled with methanol/diesel blend fuel was investigated. Methanol/diesel blend fuel was prepared, in which the methanol content is 10%, different mass fraction (0%,0.5%) of cetane number improver were added to the blend fuel. Load characteristic experiments at maximum torque speed of the engine were carried out on 4B26 direct injection diesel engine. The results show that, compared with the engine fueled with diesel, the CO emission increases under low loads and reduces under medium and high loads, the HC emission increases, the NOx emission decreases under medium and low loads and increases under high loads, the soot emission reduces significantly when the diesel engine fueled with blends. When cetane number improver was added to blends, the CO and NOx emission reduces, the HC emission decreases, the soot emission increases to some extent compared with the methanol/dieselblend fuel without cetane number improver.


Energies ◽  
2019 ◽  
Vol 12 (14) ◽  
pp. 2644 ◽  
Author(s):  
Norhidayah Mat Taib ◽  
Mohd Radzi Abu Mansor ◽  
Wan Mohd Faizal Wan Mahmood

Blending diesel with biofuels, such as ethanol and palm oil methyl ester (PME), enhances the fuel properties and produces improved engine performance and low emissions. However, the presence of ethanol, which has a small cetane number and low heating value, reduces the fuel ignitability. This work aimed to study the effect of injection strategies, compression ratio (CR), and air intake temperature (Ti) modification on blend ignitability, combustion characteristics, and emissions. Moreover, the best composition of diesel–ethanol–PME blends and engine modification was selected. A simulation was also conducted using Converge CFD software based on a single-cylinder direct injection compression ignition Yanmar TF90 engine parameter. Diesel–ethanol–PME blends that consist of 10% ethanol with 40% PME (D50E10B40), D50E25B25, and D50E40B10 were selected and conducted on different injection strategies, compression ratios, and intake temperatures. The results show that shortening the injection duration and increasing the injected mass has no significant effect on ignition. Meanwhile, advancing the injection timing improves the ignitability but with weak ignition energy. Therefore, increasing the compression ratio and ambient temperature helps ignite the non-combustible blends due to the high temperature and pressure. This modification allowed the mixture to ignite with a minimum CR of 20 and Ti of 350 K. Thus, blending high ethanol contents in a diesel engine can be applied by advancing the injection, increasing the CR, and increasing the ambient temperature. From the emission comparison, the most suitable mixtures that can be operated in the engine without modification is D50E25B25, and the most appropriate modification on the engine is by increasing the ambient temperature at 350 K.


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