Johansson Bengt. Partially Premixed Combustion, PPC, for high fuel efficiency engine operation

25 Pages·1.825 MB·English

Partially Premixed Combustion, PPC, 

for high fuel efficiency engine operation
Prof. Bengt Johansson
Division of Combustion Engines
Department of Energy Sciences
Lund University
Scania diesel engine running on gasoline
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Group 3, 1300 [rpm]
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Gross IMEP [bar]
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Path to high efficiency gasoline engine
SI HCCI PPC
Prof. Bengt Johansson
Division of Combustion Engines
Department of Energy Sciences
Lund University
Path to high efficiency gasoline engine
• Lean HCCI in three engines, 0.3‐2 l/cyl
– 50‐54% thermal efficiency 
• PPC in Volvo Cars diesel engine, 0.5l/cyl
– 56% thermal efficiency, 51% indicated
• PPC in Scania, 2 l/cyl, 17:1
– 57% indicated efficiency
• PPC in Scania 2 l/cyl, 14.3:1
– 55% indicated efficiency with high load 
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Efficiencies?
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Energy flow in an IC engine
FFuueellMMEEPP
CCoommbbuussttiioonn eeffffiicciieennccyy QQeemmiissMMEEPP
QQhhrrMMEEPP
QQhhttMMEEPP
TThheerrmmooddyynnaammiicc eeffffiicciieennccyy QQlloossssMMEEPP
QQeexxhhMMEEPP
GGrroossss IInnddiiccaatteedd eeffffiicciieennccyy IIMMEEPPggrroossss
GGaass eexxcchhaannggee eeffffiicciieennccyy PPMMEEPP
NNeett IInnddiiccaatteedd eeffffiicciieennccyy llMMEEPPnneett
MMeecchhaanniiccaall eeffffiicciieennccyy FFMMEEPP
BBrraakkee eeffffiicciieennccyy BBMMEEPP
η η η η η
= * * *
Brake Combustion Thermodynamic GasExchange Mechanical
HCCI benchmark tests
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Three test engines; five cases:
5 cyl of 0.32 l 4 cyl of 0.5 l 6 cyl of 1.95 l
• Saab SVC variable compression ratio, VCR,
1. HCCI, Rc=10:1-30:1;
• General Motors L850 “World engine”
2. HCCI, Rc=18:1
3. SI, Rc=18:1
4. SI, Rc=9.5:1 (std)
• Scania D12 Heavy duty diesel engine,
5. HCCI, Rc=18:1;
Thermodynamic efficiency
Saab SVC variable compression ratio, VCR, HCCI, Rc=10:1-30:1;
General Motors L850 “World engine”, HCCI, Rc=18:1, SI, Rc=18:1, SI, Rc=9.5:1 (std)
Scania D12 Heavy duty diesel engine, HCCI, Rc=18:1;
Fuel: US regular Gasoline
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SAE2006-01-0205
All four efficiencies
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