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Investigation on a high-stratified direct injection spark ignition (DISI) engine fueled with methanol under a high compression ratio

Li, Yaopeng LU ; Bai, Xue Song LU ; Tunér, Martin LU ; Im, Hong G. and Johansson, Bengt LU (2019) In Applied Thermal Engineering 148. p.352-362
Abstract

This paper reports an investigation of a highly stratified methanol direct injection spark ignition (DISI) engine with a high compression ratio. The effects of the start of injection (SOI), spray-included angle, injection pressure, and spark timing (ST) on in-cylinder flow, fuel distribution, flame propagation, and engine performance are evaluated in detail. The combustion process of methanol DISI engine is very sensitive to the variation of SOI, which is closely associated with the in-cylinder turbulence and the fuel/air mixing. It is found that retarding SOI shows the similar effects on combustion process as reducing spray-included angle, which indicates that the effects of SOI are more related to the spray target (i.e., fuel... (More)

This paper reports an investigation of a highly stratified methanol direct injection spark ignition (DISI) engine with a high compression ratio. The effects of the start of injection (SOI), spray-included angle, injection pressure, and spark timing (ST) on in-cylinder flow, fuel distribution, flame propagation, and engine performance are evaluated in detail. The combustion process of methanol DISI engine is very sensitive to the variation of SOI, which is closely associated with the in-cylinder turbulence and the fuel/air mixing. It is found that retarding SOI shows the similar effects on combustion process as reducing spray-included angle, which indicates that the effects of SOI are more related to the spray target (i.e., fuel distribution). The injection pressure affects the combustion process mainly through the impact on the fuel distribution in the cylinder. The flame propagates from the spark plug towards the cylinder axis along the in-cylinder swirl direction, and more fuel mass in the piston bowl promotes the flame propagation. Thus, more retarded SOI, smaller spray-included angle, and lower injection pressure are suggested at low loads to enrich the fuel concentration in the bowl to achieve a stable combustion. Under medium load, indicated thermal efficiency (ITE), peak pressure rise rate (PPRR), and nitrogen oxides (NOx) emissions can be improved with advanced SOI. ITE can also be improved by advancing ST with a slight penalty on PPRR and NOx. This study demonstrates the potential of simultaneously optimizing fuel injection and ST to improve engine performance.

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Please use this url to cite or link to this publication:
author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Direct injection spark ignition, Engine performance, Flame propagation, High compression ratio, Highly stratified methanol fuel, Spray/bowl interaction
in
Applied Thermal Engineering
volume
148
pages
11 pages
publisher
Elsevier
external identifiers
  • scopus:85056815190
ISSN
1359-4311
DOI
10.1016/j.applthermaleng.2018.11.065
language
English
LU publication?
yes
id
1eb28095-fb91-49d8-98c3-cdacfcf46705
date added to LUP
2018-11-29 10:22:40
date last changed
2019-01-06 14:17:51
@article{1eb28095-fb91-49d8-98c3-cdacfcf46705,
  abstract     = {<p>This paper reports an investigation of a highly stratified methanol direct injection spark ignition (DISI) engine with a high compression ratio. The effects of the start of injection (SOI), spray-included angle, injection pressure, and spark timing (ST) on in-cylinder flow, fuel distribution, flame propagation, and engine performance are evaluated in detail. The combustion process of methanol DISI engine is very sensitive to the variation of SOI, which is closely associated with the in-cylinder turbulence and the fuel/air mixing. It is found that retarding SOI shows the similar effects on combustion process as reducing spray-included angle, which indicates that the effects of SOI are more related to the spray target (i.e., fuel distribution). The injection pressure affects the combustion process mainly through the impact on the fuel distribution in the cylinder. The flame propagates from the spark plug towards the cylinder axis along the in-cylinder swirl direction, and more fuel mass in the piston bowl promotes the flame propagation. Thus, more retarded SOI, smaller spray-included angle, and lower injection pressure are suggested at low loads to enrich the fuel concentration in the bowl to achieve a stable combustion. Under medium load, indicated thermal efficiency (ITE), peak pressure rise rate (PPRR), and nitrogen oxides (NO<sub>x</sub>) emissions can be improved with advanced SOI. ITE can also be improved by advancing ST with a slight penalty on PPRR and NO<sub>x</sub>. This study demonstrates the potential of simultaneously optimizing fuel injection and ST to improve engine performance.</p>},
  author       = {Li, Yaopeng and Bai, Xue Song and Tunér, Martin and Im, Hong G. and Johansson, Bengt},
  issn         = {1359-4311},
  keyword      = {Direct injection spark ignition,Engine performance,Flame propagation,High compression ratio,Highly stratified methanol fuel,Spray/bowl interaction},
  language     = {eng},
  pages        = {352--362},
  publisher    = {Elsevier},
  series       = {Applied Thermal Engineering},
  title        = {Investigation on a high-stratified direct injection spark ignition (DISI) engine fueled with methanol under a high compression ratio},
  url          = {http://dx.doi.org/10.1016/j.applthermaleng.2018.11.065},
  volume       = {148},
  year         = {2019},
}