Effect of Injection Strategy on Low Temperature - Conventional Diesel Combustion Mode Transition

2015 ◽  
Author(s):  
Behzad Rohani ◽  
Stephen Sungsan Park ◽  
Choongsik Bae
Keyword(s):  
Low Temperature ◽  
Diesel Combustion ◽  
Mode Transition ◽  
Combustion Mode ◽  
Injection Strategy

Efficiency Considerations of Later-Phased Low Temperature Diesel Combustion

2010 ◽  
Author(s):  
Bryan M. Knight ◽  
Joshua A. Bittle ◽  
Timothy J. Jacobs
Keyword(s):  
Heat Transfer ◽  
Low Temperature ◽  
Conversion Efficiency ◽  
Combustion Efficiency ◽  
Diesel Combustion ◽  
Low Temperature Combustion ◽  
Combustion Mode ◽  
Fuel Conversion ◽  
Particulate Matter Emissions ◽  
Temperature Combustion

Low temperature diesel combustion offers an opportunity to simultaneously and substantially reduce exhaust nitrogen oxides and particulate matter emissions. One issue that remains an area of investigation is the improvement of engine efficiency (i.e., specific fuel consumption) for the novel mode of combustion. The objective of this article is to assess the several parameters (i.e., friction, pumping work, combustion phasing, heat transfer rate, and combustion efficiency) that affect the brake fuel conversion efficiencies of a medium-duty diesel engine as its combustion mode is transitioned from conventional to low temperature. The analysis reveals that, in this study’s development of low temperature combustion, late combustion phasing is the primary factor causing a decrease in brake fuel conversion efficiency. To enable low temperature combustion, combustion is retarded to a point where peak rate of heat release occurs at around 24° after top dead center. Such late combustion misses the opportunity to utilize the full expansion stroke of the piston. Although exhaust hydrocarbon and carbon monoxide concentrations increase as a result of the later-phased low temperature combustion mode, combustion efficiency only drops to around 90%. This decrease in combustion efficiency accounts for only about 18.7% of the corresponding decrease in brake fuel conversion efficiency (the balance decrease being caused by the later-phased combustion). Other factors that typically deteriorate brake fuel conversion efficiency (i.e., pumping work, friction, and rate of heat transfer) are all decreased with this study’s development of low temperature combustion. It is important to note that other implementations of low temperature combustion (e.g., advanced timing low temperature combustion) may not necessarily realize the same reductions in brake fuel conversion efficiency, or reductions may not necessarily be caused by the same dominant factors that are observed in this study’s later-phased low temperature combustion mode.

Low Temperature Combustion Within an HSDI Diesel Engine Using Multiple Injection Strategies

2007 ◽  
Author(s):  
Tiegang Fang ◽  
Robert E. Coverdill ◽  
Chia-Fon F. Lee ◽  
Robert A. White
Keyword(s):  
Low Temperature ◽  
Heat Release ◽  
Injection Pressure ◽  
High Load ◽  
Injection Timing ◽  
Diesel Combustion ◽  
Low Temperature Combustion ◽  
Combustion Mode ◽  
Temperature Combustion ◽  
Load Conditions

Low Temperature Compression Ignition (LTCI) combustion employing multiple injection strategies in an optical High-Speed Direct Injection (HSDI) diesel engine was investigated in this work. Heat release characteristics were analyzed through the measurement of in-cylinder pressure. The whole cycle combustion process was visualized with a high-speed digital video camera by imaging natural flame luminosity and three-dimensional-like combustion structures were obtained by taking flame images from both the bottom of the optical piston and the side window simultaneously. The NOx emissions were measured in the exhaust pipe. The effects of pilot injection timing, pilot fuel quantity, main injection timing, operating load, and injection pressure on the combustion and emissions were studied. Low temperature combustion mode was achieved by using a small pilot injection with an injection timing much earlier than TDC followed by a main injection after TDC. For comparison, experiment of a diffusion diesel combustion case was also conducted. Premixed-combustion-dominated heat release rate pattern was seen for all the low temperature combustion cases, while a typical diffusion flame combustion heat release rate was obtained for the conventional combustion case. Highly luminous flame was observed for the conventional combustion condition while much less luminous flame was seen for the low temperature combustion cases. For the higher load and lower injection pressure cases, liquid fuel being injected into low temperature premixed flame was observed for certain cases, which was different from the conventional diesel combustion with liquid fuel injected into hot premixed flame. Compared with the conventional diffusion diesel combustion, simultaneous reduction of soot and NOx was obtained for the low temperature combustion mode at both the same and increased injection pressure with similar operating load. For high load conditions, higher NOx emissions were obtained than the low load conditions with the same injection pressure due to a higher in-cylinder temperature under high load conditions with more fuel burned. However, compared with the diffusion combustion mode with a lower load at lower injection pressure, a significant reduction of soot was achieved for the high load conditions, which shows that increasing injection pressure greatly reduce soot emissions.

Solvent Injection Strategy for Low-Temperature Production from Fractured Viscous Oil Reservoirs

2014 ◽  
Vol 28 (7) ◽  
pp. 4342-4354 ◽  
Author(s):  
Kelli Rankin ◽  
Bradley Nguyen ◽  
Johan van Dorp ◽  
Marco Verlaan ◽  
Orlando Castellanos-Diaz ◽  
...  
Keyword(s):  
Low Temperature ◽  
Oil Reservoirs ◽  
Injection Strategy ◽  
Solvent Injection ◽  
Viscous Oil

Experimental study on the high load extension of PODE/methanol RCCI combustion mode with optimized injection strategy

Fuel ◽  
2021 ◽  
pp. 122726
Author(s):  
Lejian Wang ◽  
Junheng Liu ◽  
Qian Ji ◽  
Ping Sun ◽  
Jie Li ◽  
...  
Keyword(s):  
Experimental Study ◽  
High Load ◽  
Combustion Mode ◽  
Injection Strategy

Effects of fuel properties on combustion and pollutant emissions of a low temperature combustion mode diesel engine

Fuel ◽  
2020 ◽  
Vol 267 ◽  
pp. 117123 ◽  
Author(s):  
Song Li ◽  
Jinping Liu ◽  
Yu Li ◽  
Mingrui Wei ◽  
Helin Xiao ◽  
...  
Keyword(s):  
Diesel Engine ◽  
Low Temperature ◽  
Fuel Properties ◽  
Pollutant Emissions ◽  
Low Temperature Combustion ◽  
Combustion Mode ◽  
Temperature Combustion

The role of low temperature chemistry in combustion mode development under elevated pressures

2016 ◽  
Vol 174 ◽  
pp. 179-193 ◽  
Author(s):  
Jiaying Pan ◽  
Haiqiao Wei ◽  
Gequn Shu ◽  
Zheng Chen ◽  
Peng Zhao
Keyword(s):  
Low Temperature ◽  
Combustion Mode ◽  
Elevated Pressures ◽  
Low Temperature Chemistry
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