scholarly journals Effect of Pre-Injection on Combustion and Emission Characteristics of a Diesel Engine Fueled with Diesel/Methanol/n-Butanol Blended Fuel

Processes ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 60
Author(s):  
Zhiqiang Wang ◽  
Lijun Li

In this study, the combustion and emission characteristics of a diesel/methanol/n-butanol blended fuel engine with different pre-injection timings and pre-injection mass ratios were investigated by a computational fluid dynamics (CFD) model. The CFD model was verified by the measured results and coupled with a simplified chemical kinetics mechanism. Firstly, the corresponding three-dimensional CFD model was established by CONVERGE software and the CHEKMIN program, and a chemical kinetic mechanism containing 359 reactions and 77 species was developed. Secondly, the combustion and emission characteristics of the diesel engine with different diesel/methanol/n-butanol blended fuels were analyzed and discussed. The results showed that increases in the pre-injection timing and the pre-injection mass ratio could increase cylinder pressure and cylinder temperature and decrease soot, HC, and CO emissions. At 100% load, the maximum cylinder pressures at the start of pre-injection timing from −15 °CA to −45 °CA, were 7.71, 9.46, 9.85, 9.912, and 9.95 MPa, respectively. The maximum cylinder pressures at pre-injection fuel mass ratios from 0.1 to 0.9 were 7.98, 9.10, 9.96, 10.52, and 11.16 MPa, respectively. At 50% load, with increases of the pre-injection timing and pre-injection fuel mass ratio, the soot emission decreased by 7.30%, 9.45%, 27.70%, 66.80%, 81.80% and 11.30%, 20.03%, 71.32%, 83.80%, 93.76%, respectively, and CO emissions were reduced by 5.77%, 12.31%, 22.73%, 53.59%, 63.22% and 8.29%, 43.97%, 53.59%, 58.86%, 61.18%, respectively. However, with increases of the pre-injection timing and pre-injection mass ratio, NOx emission increased. In addition, it was found that the optimal pre-injection timing and optimal pre-injection mass ratio should be −30 °CA and 0.5, respectively. Therefore, through this study we can better understand the potential interaction of relevant parameters and propose pre-injection solutions to improve combustion and emission characteristics.

Processes ◽  
2021 ◽  
Vol 9 (11) ◽  
pp. 1944
Author(s):  
Shaoji Chen ◽  
Jie Tian ◽  
Jiangtao Li ◽  
Wangzhen Li ◽  
Zhiqing Zhang

In this paper, the effects of different diesel–methanol blends on the combustion and emission characteristics of diesel engines are investigated in terms of cylinder pressure, heat release rate, cylinder temperature, brake specific fuel consumption, thermal brake efficiency, brake power, and soot, nitrogen oxides, and carbon monoxide emissions in a four-stroke diesel engine. The corresponding three-dimensional Computational Fluid Dynamics (CFD) model was established using the Anstalt für Verbrennungskraftmaschinen List (AVL)-Fire coupled Chemkin program, and the chemical kinetic mechanism, including 135 reactions and 77 species, was established. The simulation model was verified by the experiment at 50% and 100% loads, and the combustion processes of pure diesel (D100) and diesel–methanol (D90M10, D80M20, and D70M30) were investigated, respectively. The results showed that the increase in methanol content in the blended fuel significantly improved the emission and power characteristics of the diesel engine. More specifically, at full load, the cylinder pressures increased by 0.78%, 1.21%, and 1.41% when the proportions of methanol in the blended fuel were 10%, 20%, and 30%, respectively. In addition, the power decreased by 2.76%, 5.04%, and 8.08%, respectively. When the proportion of methanol in the blended fuel was 10%, 20%, and 30%, the soot emissions were decreased by 16.45%, 29.35%, and 43.05%, respectively. Therefore, methanol content in blended fuel improves the combustion and emission characteristics of the engine.


In this world, the population is increased and the number of vehicles increased. Not only population the pollution is increased lot by vehicles in the world harmful pollutant is realized from the vehicles like CO, HC, NOx and smoke particulates. It is inevitable to find some new technology, which increases the better performance and emission characteristics. Partially premixed compression ignition (PCCI) is the best technology for the reducing of harmful pollution in the vehicle, which uses the diesel as fuel it, gives the advantages of both CI and SI engine. This paper investigates the performance and emission characteristics of partially premixed diesel engine. Diesel engine has two injectors of port fuel injector (PFI) and direct injector (DI) to inject the fuel in different timing and electrical control unit (ECU) passes the power to PFI; it can control the injection timing and increases the fuel content from the fuel pump. The main aim in this paper is studied is effect of partially premixed ratio, performance of engine and emission characteristics of diesel engine


2021 ◽  
Vol 9 (1) ◽  
pp. 436-443
Author(s):  
M.Kannan, R.Balaji, R.T Sarath Babu, Chandrakant B. Shende, Ashish Selokar

The primary objective of this study is to discover the effects of injection timing on performance, emission and combustion characteristics effect of advanced and retarded injection timing of the engine fuelled with mahua oil biodiesel blends. The engine performance, combustion and emission characteristics of the mahua oil biodiesel blends (B20, B40, B60, B80and B100) are investigated in this experimentation without any modification of the diesel engine. At this advanced pressure t he efficiency of engine by means of CO, Unburned HC gases and smoke emissions with higher oxides of nitrogen was observed compared to diesel. The obtained results are compared with a neat diesel and mahua oil biodiesel blends are shown through the graphs. From this study, identifies optimum fuel blend of this work. Thus, the combustion of duration is similar in all variance in pressure. This research paved a way to bio-diesel in mahua oil mixture and draws best outcome in emission less and to maintain eco-friendly environment.  


Author(s):  
Hyun Kyu Suh ◽  
Hyun Gu Roh ◽  
Chang Sik Lee

The aim of this work is to investigate the effect of the blending ratio and pilot injection on the spray and combustion characteristics of biodiesel fuel and compare these factors with those of diesel fuel in a direct injection common-rail diesel engine. In order to study the factors influencing the spray and combustion characteristics of biodiesel fuel, experiments involving exhaust emissions and engine performance were conducted at various biodiesel blending ratios and injection conditions for engine operating conditions. The macroscopic and microscopic spray characteristics of biodiesel fuel, such as injection rate, split injection effect, spray tip penetration, droplet diameter, and axial velocity distribution, were compared with the results from conventional diesel fuel. For biodiesel blended fuel, it was revealed that a higher injection pressure is needed to achieve the same injection rate at a higher blending ratio. The spray tip penetration of biodiesel fuel was similar to that of diesel. The atomization characteristics of biodiesel show that it has higher Sauter mean diameter and lower spray velocity than conventional diesel fuel due to high viscosity and surface tension. The peak combustion pressures of diesel and blending fuel increased with advanced injection timing and the combustion pressure of biodiesel fuel is higher than that of diesel fuel. As the pilot injection timing is retarded to 15deg of BTDC that is closed by the top dead center, the dissimilarities of diesel and blending fuels combustion pressure are reduced. It was found that the pilot injection enhanced the deteriorated spray and combustion characteristics of biodiesel fuel caused by different physical properties of the fuel.


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