Diesel Injection Strategy in a Premixed Charge Compression Ignition Engine Under a Low Load

The present paper aims to assess the impacts of diesel injection timing and two bowl geometries including re-entrant and wide-shallow combustion chambers on the combustion characteristics, emissions formation, and fuel consumption in a reactivity controlled compression ignition diesel engine under low and high load (five and nine bar indicating mean effective pressure) conditions. The results revealed that diesel injection at −60 CA ATDC under low load conditions significantly decreased soot and NOx emissions simultaneously for both piston bowl geometries. The use of the wide-shallow chamber decreased the period of the ignition delay and increased the engine operable load range as a result of more stable combustion under high-load conditions compared to the re-entrant chamber. Moreover, at all diesel injection timings, the indicated specific fuel consumption was decreased by nearly 4.8 and 6.6% under low and high load conditions, respectively when the wide-shallow combustion chamber was used since the heat transfer loss was lower than that of the re-entrant chamber. However, NOx emission under high load conditions at the center of the combustion chamber and more soot emission in the exhaust gas are two disadvantages of the wide-shallow chamber versus the re-entrant combustion chamber.

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An Experimental Investigation on Low Load Combustion Stability and Cold-Firing Capacity of a Gasoline Compression Ignition Engine

Engineering ◽

10.1016/j.eng.2018.12.010 ◽

2019 ◽

Vol 5 (3) ◽

pp. 558-567 ◽

Cited By ~ 3

Author(s):

Lei Zhou ◽

Jianxiong Hua ◽

Haiqiao Wei ◽

Yiyong Han

Keyword(s):

Experimental Investigation ◽

Combustion Stability ◽

Compression Ignition ◽

Compression Ignition Engine ◽

Low Load

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Effects of fuel injection parameters on premixed charge compression ignition combustion and emission characteristics in a medium-duty compression ignition diesel engine

International Journal of Engine Research ◽

10.1177/1468087419867014 ◽

2019 ◽

pp. 146808741986701 ◽

Cited By ~ 1

Author(s):

Santiago Molina ◽

Antonio García ◽

Javier Monsalve-Serrano ◽

David Villalta

Keyword(s):

Diesel Engine ◽

Fuel Injection ◽

Transport Sector ◽

Injection Timing ◽

Compression Ignition ◽

Injection Strategy ◽

Low Load ◽

Main Injection ◽

Compression Ignition Combustion ◽

The Impact

From the different power plants, the compression ignition diesel engines are considered the best alternative to be used in the transport sector due to its high efficiency. However, the current emission standards impose drastic reductions for the main pollutants, that is, NO x and soot, emitted by this type of engines. To accomplish with these restrictions, alternative combustion concepts as the premixed charge compression ignition are being investigated nowadays. The objective of this work is to evaluate the impact of different fuel injection strategies on the combustion performance and engine-out emissions of the premixed charge compression ignition combustion regime. For that, experimental measurements were carried out in a single-cylinder medium-duty compression ignition diesel engine at low-load operation. Different engine parameters as the injection pattern timing, main injection timing and main injection fuel quantity were sweep. The best injection strategy was determined by means of a methodology based on the evaluation of a merit function. The results suggest that the best injection strategy for the low-load premixed charge compression ignition operating condition investigated implies using a high injection pressure and a triple-injection event with a delayed main injection with almost 15% of the total fuel mass injected.

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