Effect of Fuel Properties on the Performance of DI Diesel Engine with Fuel Jet Impingement

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.

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Effect of Preheating Temperature and Fuel Properties on Combustion and Emission Characteristics of Homogeneous Charge Compression Ignition (HCCI) Engine

International Journal of Emerging Trends in Engineering Research ◽

10.30534/ijeter/2021/04952021 ◽

2021 ◽

Vol 9 (5) ◽

pp. 558-564

Keyword(s):

Experimental Investigation ◽

Diesel Engine ◽

Air Temperature ◽

Homogeneous Charge Compression Ignition ◽

Fuel Properties ◽

Emission Characteristics ◽

Compression Ignition ◽

Hcci Engine ◽

Di Diesel Engine ◽

Homogeneous Charge

The homogeneous charge compression ignition (HCCI) engine is the promising technology to reduce the pollutants without affecting its performance and it is also proved by the many studies. This study investigates the performance and emission characteristics of HCCI engine fuelled with diesel –waste cooking oil (WCO) blends and also analysed the effect of air temperature and fuel properties on HCCI engine combustion. The experimental investigation was conducted with single cylinder DI diesel engine and it was slightly modified to port injection system for premixing the charge. The electric air heater was adopted in suction pipe to preheat the inlet air. The experimental investigation conducted in two phases, in the first phase the conventional DI diesel engine was tested with different fuel blends such as B25, B50, B75 and B100 and notes the readings. In the next phase, HCCI engine was operated with same blend ratios. During the experimentation on HCCI engine, the suction air temperature was varied between 40⁰C to 90⁰C. From the experimental results, it was found that the HCCI engine has emitted low NOx and smoke emissions at 80⁰C of air temperature for all the blends. Whereas the HCCI engine emitted more carbon monoxide (CO) and hydrocarbon (HC) emissions due to lean mixture causes misfiring in the chamber. In addition, it is also noted that the value of CO and HC has been varied with diesel –WCO blends. The specific fuel consumption (SFC) is increased for diesel and biodiesel fuel in HCCI engine compared to compression ignition (CI) engine

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Thermodynamic Analysis of the Effects of Fuel-Side and Air-Side Oxygen Addition on Diesel Engine Combustion Characteristics and Pollutant Formation

Volume 3: Combustion Science and Engineering ◽

10.1115/imece2008-66367 ◽

2008 ◽

Author(s):

Theodoros C. Zannis ◽

Dimitrios T. Hountalas ◽

Elias A. Yfantis ◽

Roussos G. Papagiannakis

Keyword(s):

Diesel Engine ◽

Formation Mechanism ◽

Soot Formation ◽

Oxygen Availability ◽

Combustion Characteristics ◽

Pollutant Emissions ◽

Fuel Jet ◽

Di Diesel Engine ◽

Oxygen Addition ◽

Oxygen Enhancement

A multi-zone combustion model is used in the present study to examine the effect of increased in-cylinder oxygen availability (either by using oxygenated fuels or by increasing the oxygen percentage of intake air) on direct injection (DI) diesel engine performance characteristics and pollutant emissions. Simulations are produced for a single-cylinder DI diesel engine (“Lister LV1”) by keeping constant the oxygen content of in-cylinder fuel/air mixture and the engine brake torque. The effects of the two oxygen-enhancement techniques on combustion characteristics, soot and NO concentrations inside the combustion chamber are examined using model predictions for a common diesel oil, a neat oxygenate and the case of increasing the oxygen fraction of intake air. The multi-zone model is also utilized to interpret the relative impact of fuel-side and air-side oxygen on soot formation mechanism by examining the temporal evolution of combustion characteristics and soot formation and oxidation rates inside the fuel jet zones. Evaluation of the theoretical results revealed that the increase of in-cylinder oxygen availability by both techniques resulted in earlier initiation of combustion, increase of peak cylinder pressure and increase of in-cylinder and exhaust NO concentrations. It resulted also in reduction of exhaust gas temperature and exhaust soot values. Fuel oxygen addition was proven to be more influential on combustion process and consequently, on soot and NO formation mechanism compared to oxygen-enhancement of intake air. This is attributed to the higher oxygen availability inside each fuel jet zone, which is observed in the case of oxygenated fuel combustion.

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