Abstract
The effects of spray impingement, injection parameters, and exhaust gas recirculation (EGR) on the combustion characteristics and exhaust emissions of a premixed charge compression ignition (PCCI) diesel engine were investigated using a single-cylinder test engine and an optically accessible engine. Tests were carried out under constant speed with variable injection pressures and EGR rates. Exhaust emissions and in-cylinder pressures were measured under all experimental conditions. Analyses were conducted based on diesel spray evolution and combustion process visualisation coupled with performance and exhaust emissions. Higher injection pressures led to lower smoke, hydrocarbons (HC), and nitrogen oxide (NO x) emissions but had roughly the same CO emissions compared with lower injection pressures. Higher EGR rates led to the simultaneous reduction in NO x and soot emissions due to lower combustion temperatures compared to conventional diesel combustion. However, HC and CO emissions increased due to fuel impingement, bulk quenching, and over-mixing, leading to an air-fuel mixture that was too lean to burn. An optimum spray targeting spot was identified, leading to lower emissions of soot, CO, and HC but higher NO x emissions without EGR. The simultaneous reduction in NO x and soot was achieved using the optimum spray targeting spot by introducing EGR, which was accompanied by homogenous combustion and a low luminosity flame attributed to fuel impingement on the piston bowl wall.
| Original language | English |
|---|---|
| Pages (from-to) | 165-175 |
| Number of pages | 11 |
| Journal | Applied Thermal Engineering |
| Volume | 37 |
| DOIs | |
| Publication status | Published - May 2012 |
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Keywords
- Air-fuel mixture
- Exhaust emissions
- Flame luminosity
- Internal combustion engine
- PCCI
- Spray
ASJC Scopus subject areas
- Energy Engineering and Power Technology
- Industrial and Manufacturing Engineering
Cite this
Effects of spray impingement, injection parameters, and EGR on the combustion and emission characteristics of a PCCI diesel engine. / Kiplimo, Robert; Tomita, Eiji; Kawahara, Nobuyuki; Yokobe, Sumito.
In: Applied Thermal Engineering, Vol. 37, 05.2012, p. 165-175.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Effects of spray impingement, injection parameters, and EGR on the combustion and emission characteristics of a PCCI diesel engine
AU - Kiplimo, Robert
AU - Tomita, Eiji
AU - Kawahara, Nobuyuki
AU - Yokobe, Sumito
PY - 2012/5
Y1 - 2012/5
N2 - The effects of spray impingement, injection parameters, and exhaust gas recirculation (EGR) on the combustion characteristics and exhaust emissions of a premixed charge compression ignition (PCCI) diesel engine were investigated using a single-cylinder test engine and an optically accessible engine. Tests were carried out under constant speed with variable injection pressures and EGR rates. Exhaust emissions and in-cylinder pressures were measured under all experimental conditions. Analyses were conducted based on diesel spray evolution and combustion process visualisation coupled with performance and exhaust emissions. Higher injection pressures led to lower smoke, hydrocarbons (HC), and nitrogen oxide (NO x) emissions but had roughly the same CO emissions compared with lower injection pressures. Higher EGR rates led to the simultaneous reduction in NO x and soot emissions due to lower combustion temperatures compared to conventional diesel combustion. However, HC and CO emissions increased due to fuel impingement, bulk quenching, and over-mixing, leading to an air-fuel mixture that was too lean to burn. An optimum spray targeting spot was identified, leading to lower emissions of soot, CO, and HC but higher NO x emissions without EGR. The simultaneous reduction in NO x and soot was achieved using the optimum spray targeting spot by introducing EGR, which was accompanied by homogenous combustion and a low luminosity flame attributed to fuel impingement on the piston bowl wall.
AB - The effects of spray impingement, injection parameters, and exhaust gas recirculation (EGR) on the combustion characteristics and exhaust emissions of a premixed charge compression ignition (PCCI) diesel engine were investigated using a single-cylinder test engine and an optically accessible engine. Tests were carried out under constant speed with variable injection pressures and EGR rates. Exhaust emissions and in-cylinder pressures were measured under all experimental conditions. Analyses were conducted based on diesel spray evolution and combustion process visualisation coupled with performance and exhaust emissions. Higher injection pressures led to lower smoke, hydrocarbons (HC), and nitrogen oxide (NO x) emissions but had roughly the same CO emissions compared with lower injection pressures. Higher EGR rates led to the simultaneous reduction in NO x and soot emissions due to lower combustion temperatures compared to conventional diesel combustion. However, HC and CO emissions increased due to fuel impingement, bulk quenching, and over-mixing, leading to an air-fuel mixture that was too lean to burn. An optimum spray targeting spot was identified, leading to lower emissions of soot, CO, and HC but higher NO x emissions without EGR. The simultaneous reduction in NO x and soot was achieved using the optimum spray targeting spot by introducing EGR, which was accompanied by homogenous combustion and a low luminosity flame attributed to fuel impingement on the piston bowl wall.
KW - Air-fuel mixture
KW - Exhaust emissions
KW - Flame luminosity
KW - Internal combustion engine
KW - PCCI
KW - Spray
UR - http://www.scopus.com/inward/record.url?scp=84856374786&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84856374786&partnerID=8YFLogxK
U2 - 10.1016/j.applthermaleng.2011.11.011
DO - 10.1016/j.applthermaleng.2011.11.011
M3 - Article
AN - SCOPUS:84856374786
VL - 37
SP - 165
EP - 175
JO - Applied Thermal Engineering
JF - Applied Thermal Engineering
SN - 1359-4311
ER -