An Investigation of the Low Temperature Combustion Regime (LTC) in a Small Bore HSDI Diesel Engine

2005 ◽  
Author(s):  
Jasmeet Singh ◽  
Yusuf Poonawala ◽  
Inderpal Singh ◽  
Naeim A. Henein ◽  
Walter Bryzik
Keyword(s):  
Diesel Engine ◽  
Low Temperature ◽  
Fuel Economy ◽  
Combustion Regime ◽  
Injection System ◽  
Fuel Vapor ◽  
Low Temperature Combustion ◽  
Wide Range ◽  
Temperature Combustion ◽  
Hsdi Diesel Engine

The low temperature combustion regime (LTC) has been known to simultaneously reduce both NOx and smoke emissions. The concept is to burn the fuel vapor-air charge, low in oxygen concentration, at low temperatures to reduce the formation of both NOx and smoke emissions. The paper investigates two combustion concepts in the LTC regime, the MK (modulated kinetics) and the smokeless locally rich diesel combustion and proposes a new strategy for a further reduction in emissions with minimum penalty in fuel economy. Tests were carried out under simulated turbo charged conditions on a single cylinder, small bore HSDI diesel engine with a re-entrant bowl combustion chamber. The engine is equipped with a common rail fuel injection system. Tests covered a wide range of injection pressures, EGR rates, injection timings and swirl ratios to determine their individual and collective contributions in engine-out emissions and fuel economy within this combustion regime. The proposed strategy is based on the results of this experimental investigation.

Enhancing Low-Temperature Combustion With Biodiesel Blending in a Diesel Engine at a Medium Load Condition

2015 ◽  
Vol 138 (4) ◽  
Author(s):  
Sunyoup Lee ◽  
Seungmook Oh ◽  
Junghwan Kim ◽  
Duksang Kim
Keyword(s):  
Diesel Engine ◽  
Low Temperature ◽  
Oxygen Concentration ◽  
Load Condition ◽  
Low Temperature Combustion ◽  
Effective Pressure ◽  
Oxygen Level ◽  
Indicated Mean Effective Pressure ◽  
Wide Range ◽  
Temperature Combustion

The present study investigated the effects of biodiesel blending under a wide range of intake oxygen concentration levels in a diesel engine. This study attempted to identify the lowest biodiesel blending rate that achieves acceptable levels of nitric oxides (NOx), soot, and coefficient of variation in the indicated mean effective pressure (COVIMEP). Biodiesel blending was to be minimized in order to reduce the fuel penalty associated with the biodiesels lower caloric value (LCV). Engine experiments were performed in a 1 l single-cylinder diesel engine at an engine speed of 1400 rev/min under a medium load condition. The blend rate and intake oxygen concentration were varied independently of each other at a constant intake pressure of 200 kPa. The biodiesel blend rate varied from 0% (B000) to 100% biodiesel (B100) at a 20% increment. The intake oxygen level was adjusted from 8% to 19% by volume (vol. %) in order to embrace both conventional and low-temperature combustion (LTC) operations. A fixed injection duration of 788 ms at a fuel rail pressure of 160 MPa exhibited a gross indicated mean effective pressure (IMEP) between 750 kPa and 910 kPa, depending on the intake oxygen concentration. The experimental results indicated that the intake oxygen level had to be below 10 vol. % to achieve the indicated specific NOx (ISNOx) below 0.2 g/kW h with the B000 fuel. However, a substantial soot increase was exhibited at such a low intake oxygen level. Biodiesel blending reduced NOx until the blending rate reached 60% with reduced in-cylinder temperature due to lower total energy release. As a result, 60% biodiesel-blended diesel (B060) achieved NOx, soot, and COVIMEP of 0.2 g/kW h, 0.37 filter smoke number (FSN), and 0.5, respectively, at an intake oxygen concentration of 14 vol. %. The corresponding indicated thermal efficiency was 43.2%.

Enhancing Low Temperature Combustion With Biodiesel Blending in a Diesel Engine at a Medium Load Condition

2014 ◽  
Author(s):  
Sunyoup Lee ◽  
Seungmook Oh ◽  
Junghwan Kim ◽  
Duksang Kim
Keyword(s):  
Diesel Engine ◽  
Low Temperature ◽  
Oxygen Concentration ◽  
Load Condition ◽  
Low Temperature Combustion ◽  
Effective Pressure ◽  
Oxygen Level ◽  
Indicated Mean Effective Pressure ◽  
Wide Range ◽  
Temperature Combustion

The present study investigated the effects of biodiesel blending under a wide range of intake oxygen concentration levels in a diesel engine. This study attempted to identify the lowest biodiesel blending rate that achieves acceptable levels of nitric oxides (NOx), soot, and coefficient of variation in the indicated mean effective pressure (COVIMEP). Biodiesel blending was to be minimized in order to reduce the fuel penalty associated with the biodiesels lower caloric value. Engine experiments were performed in a 1-liter single-cylinder diesel engine at an engine speed of 1400 rev/min under a medium load condition. The blend rate and intake oxygen concentration were varied independently of each other at a constant intake pressure of 200 kPa. The biodiesel blend rate varied from 0% (B000) to 100% biodiesel (B100) at a 20% increment. The intake oxygen level was adjusted from 8 to 19% by volume (vol %) in order to embrace both conventional and low-temperature combustion (LTC) operations. A fixed injection duration of 788 μs at a fuel rail pressure of 160 MPa exhibited a gross indicated mean effective pressure (IMEP) between 750 kPa and 910 kPa, depending on the intake oxygen concentration. The experimental results indicated that the intake oxygen level had to be below 10 vol% to achieve the indicated specific NOx (ISNOx) below 0.2g/kWhr with the B000 fuel. However, a substantial soot increase was exhibited at such a low intake oxygen level. Biodiesel blending reduced NOx until the blending rate reached 60% with reduced in-cylinder temperature due to lower total energy release. As a result, 60%-biodiesel blended diesel (B060) achieved NOx, soot, and COVIMEP of 0.2 g/kWhr, 0.37 filter smoke number (FSN), and 0.5, respectively, at an intake oxygen concentration of 14 vol%. The corresponding indicated thermal efficiency was 43.2%.

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