05/01969 Soot in diesel fuel jets: effects of ambient temperature, ambient density, and injection pressure

2005 ◽  
Vol 46 (5) ◽  
pp. 293 ◽  
1993 ◽  
Vol 115 (4) ◽  
pp. 777-780 ◽  
Author(s):  
Gong Yunyi ◽  
Liang Xuanming

An investigation of the effect of ambient gas temperature and density on diesel fuel spray penetration, spray angle, and wall impingement at an injection pressure of 75–134 MPa was conducted in a constant-volume bomb with a reconstructed Cummins PT fuel system by using a high-speed photographic technique. The results show that penetration does not increase monotonically with injection pressure, and ambient temperature has more effect on a high-pressure spray than on those with conventional pressures. With the high temperature, the penetration of a high injection pressure spray is reduced a bit, while the spray angle increases obviously. When the high-pressure spray impinges on a wall at ordinary temperature, the rebounding droplets can hardly be seen, but at higher wall temperature, a cloud of dense spray will be observed near the wall, and sometimes a vapor layer will be formed between the spray and the wall. Based on experimental results, an empirical formula considering the effects of both the ambient temperature and injection pressure is presented.


Energies ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3215
Author(s):  
David Fernández-Rodríguez ◽  
Magín Lapuerta ◽  
Lizzie German

Nowadays, the transport sector is trying to face climate change and to contribute to a sustainable world by introducing modern after-treatment systems or by using biofuels. In sectors such as road freight transportation, agricultural or cogeneration in which the electrification is not considered feasible with the current infrastructure, renewable options for diesel engines such as alcohols produced from waste or lignocellulosic materials with advanced production techniques show a significant potential to reduce the life-cycle greenhouse emissions with respect to diesel fuel. This study concludes that lignocellulosic biobutanol can achieve 60% lower greenhouse gas emissions than diesel fuel. Butanol-diesel blends, with up to 40% butanol content, could be successfully used in a diesel engine calibrated for 100% diesel fuel without any additional engine modification nor electronic control unit recalibration at a warm ambient temperature. When n-butanol is introduced, particulate matter emissions are sharply reduced for butanol contents up to 16% (by volume), whereas NOX emissions are not negatively affected. Butanol-diesel blends could be introduced without startability problems up to 13% (by volume) butanol content at a cold ambient temperature. Therefore, biobutanol can be considered as an interesting option to be blended with diesel fuel, contributing to the decarbonization of these sectors.


2017 ◽  
Vol 11 (2) ◽  
pp. 2723-2733 ◽  
Author(s):  
Norrizam Jaat ◽  
◽  
Amir Khalid ◽  
Adiba Rhaodah Andsaler ◽  
Azwan Sapit ◽  
...  

2015 ◽  
Vol 19 (6) ◽  
pp. 1943-1957
Author(s):  
Simona Merola ◽  
Luca Marchitto ◽  
Cinzia Tornatore ◽  
Gerardo Valentino

Combustion process was studied from the injection until the late combustion phase in an high swirl optically accessible combustion bowl connected to a single cylinder 2-stroke high pressure common rail compression ignition engine. Commercial diesel and blends of diesel and n-butanol (20%: BU20 and 40%: BU40) were used for the experiments. A pilot plus main injection strategy was investigated fixing the injection pressure and fuel mass injected per stroke. Two main injection timings and different pilot-main dwell times were explored achieving for any strategy a mixing controlled combustion. Advancing the main injection start, an increase in net engine working cycle (>40%) together with a strong smoke number decrease (>80%) and NOx concentration increase (@50%) were measured for all pilot injection timings. Compared to diesel fuel, butanol induced a decrease in soot emission and an increase in net engine working area when butanol ratio increased in the blend. A noticeable increase in NOx was detected at the exhaust for BU40 with a slight effect of the dwell-time. Spectroscopic investigations confirmed the delayed auto-ignition (~60 ms) of the pilot injection for BU40 compared to diesel. The spectral features for the different fuels were comparable at the start of combustion process, but they evolved in different ways. Broadband signal caused by soot emission, was lower for BU40 than diesel. Different balance of the bands at 309 and 282 nm, due to different OH transitions, were detected between the two fuels. The ratio of these intensities was used to follow flame temperature evolution.


Author(s):  
M P Ashok ◽  
C G Saravanan

Diesel engines are employed as the major propulsion power sources because of their simple, robust structure and high fuel economy. It is expected that diesel engines will be widely used in the foreseeable future. However, an increase in the use of diesel engines causes a shortage of fossil fuel and results in a greater degree of pollution. To regulate the above, identifying an alternative fuel to the diesel engine with less pollution is essential. Ethanol–diesel emulsion is one such method, used for the preparation of an alternative fuel for the diesel engine. Experimental investigations were carried out to compare the performance of diesel fuel with different ratios 50D: 50E (50 per cent diesel No: 2: 50 per cent ethanol –100 per cent proof) and 60D: 40E emulsified fuels. In the next phase, experiments were conducted for the selected emulsified fuel ratio 50D: 50E for different high injection pressures and the results are compared. The results show that for the emulsified fuel ratios, there is a marginal increase in torque, power, NO x, emissions, and decreasing values of carbon monoxide (CO), sulphur dioxide (SO2) emissions at the maximum speed conditions, compared with diesel fuel. Also, it is found that an increase in injection pressure of the engine running with emulsified fuel decreases CO and smoke emissions especially between 1500 to 2000 r/min with respect to the diesel fuel.


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.


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