Diesel-Ignited Propane Dual Fuel Low Temperature Combustion in a Heavy-Duty Diesel Engine

2014 ◽  
Vol 136 (9) ◽  
Author(s):  
Andrew C. Polk ◽  
Chad D. Carpenter ◽  
E. Scott Guerry ◽  
U. Dwivedi ◽  
Kalyan Kumar Srinivasan ◽  
...  
Keyword(s):  
Diesel Engine ◽  
Low Temperature ◽  
Dual Fuel ◽  
Boost Pressure ◽  
Low Temperature Combustion ◽  
Heavy Duty ◽  
Diesel Injection ◽  
Heavy Duty Diesel Engine ◽  
Temperature Combustion ◽  
Heavy Duty Diesel

This paper presents an experimental analysis of diesel-ignited propane dual fuel low temperature combustion (LTC) based on performance, emissions, and in-cylinder combustion data from a modern, heavy-duty diesel engine. The engine used for these experiments was a 12.9-liter, six-cylinder, direct injection heavy-duty diesel engine with electronic unit diesel injection pumps, a variable geometry turbocharger, and cooled exhaust gas recirculation (EGR). The experiments were performed with gaseous propane (the primary fuel) fumigated upstream of the turbocharger and diesel (the pilot fuel) injected directly into the cylinders. Results are presented for a range of diesel injection timings (SOIs) from 10 deg BTDC to 50 deg BTDC at a brake mean effective pressure (BMEP) of 5 bar and a constant engine speed of 1500 rpm. The effects of SOI, percent energy substitution (PES) of propane (i.e., replacement of diesel fuel energy with propane), intake boost pressure, and cooled EGR on the dual fuel LTC process were investigated. The approach was to determine the effects of SOI while maximizing the PES of propane. Dual fuel LTC was achieved with very early SOIs (e.g., 50 deg BTDC) coupled with high propane PES (>84%), which yielded near-zero NOx (<0.02 g/kW h) and very low smoke emissions (<0.1 FSN). Increasing the propane PES beyond 84% at the SOI of 50 deg BTDC yielded a high COV of IMEP due to retarded combustion phasing (CA50). Intake boost pressures were increased and EGR rates were decreased to minimize the COV, allowing higher propane PES (∼93%); however, lower fuel conversion efficiencies (FCE) and higher HC and CO emissions were observed.

Diesel-Ignited Propane Dual Fuel Low Temperature Combustion in a Heavy-Duty Diesel Engine

2013 ◽  
Author(s):  
A. C. Polk ◽  
C. D. Carpenter ◽  
E. S. Guerry ◽  
U. Dwivedi ◽  
K. K. Srinivasan ◽  
...  
Keyword(s):  
Diesel Engine ◽  
Low Temperature ◽  
Dual Fuel ◽  
Boost Pressure ◽  
Low Temperature Combustion ◽  
Heavy Duty ◽  
Diesel Injection ◽  
Heavy Duty Diesel Engine ◽  
Temperature Combustion ◽  
Heavy Duty Diesel

This paper presents an experimental analysis of diesel-ignited propane dual fuel low temperature combustion (LTC) based on performance, emissions, and in-cylinder combustion data from a modern, heavy-duty diesel engine. The engine used for these experiments was a 12.9-liter, six-cylinder, direct injection heavy-duty diesel engine with electronic unit diesel injection pumps, a variable geometry turbocharger, and cooled exhaust gas recirculation (EGR). The experiments were performed with gaseous propane (the primary fuel) fumigated upstream of the turbocharger and diesel (the pilot fuel) injected directly into the cylinders. Results are presented for a range of diesel injection timings (SOIs) from 10° BTDC to 50° BTDC at a brake mean effective pressure (BMEP) of 5 bar and a constant engine speed of 1500 RPM. The effects of SOI, percent energy substitution (PES) of propane (i.e., replacement of diesel fuel energy with propane), intake boost pressure, and cooled EGR on the dual fuel LTC process were investigated. The approach was to determine the effects of SOI while maximizing the PES of propane. Dual fuel LTC was achieved with very early SOIs (e.g., 50° BTDC) coupled with high propane PES (> 84%), which yielded near-zero NOx (< 0.02 g/kW-hr) and very low smoke emissions (< 0.1 FSN). Increasing the propane PES beyond 84% at the SOI of 50° BTDC yielded a high COV of IMEP due to retarded combustion phasing (CA50). Intake boost pressures were increased and EGR rates were decreased to minimize the COV, allowing higher propane PES (∼ 93%); however, lower fuel conversion efficiencies (FCE) and higher HC and CO emissions were observed.

scholarly journals Optical Diagnostics of a Late Injection Low-Temperature Combustion in a Heavy Duty Diesel Engine

2007 ◽  
Author(s):  
Thierry Lachaux ◽  
Mark P. B. Musculus ◽  
Satbir Singh ◽  
Rolf D. Reitz
Keyword(s):  
Diesel Engine ◽  
Low Temperature ◽  
Liquid Fuel ◽  
Premixed Combustion ◽  
Low Temperature Combustion ◽  
Heavy Duty ◽  
Cool Flame ◽  
Heavy Duty Diesel Engine ◽  
Temperature Combustion ◽  
Heavy Duty Diesel

A late injection, high exhaust-gas recirculation (EGR)-rate, low-temperature combustion strategy was investigated in a heavy-duty diesel engine using a suite of optical diagnostics: chemiluminescence for visualization of ignition and combustion, laser Mie scattering for liquid fuel imaging, planar laser-induced fluorescence (PLIF) for both OH and vapor-fuel imaging, and laser-induced incandescence (LII) for soot imaging. Fuel is injected at top dead center when the in-cylinder gases are hot and dense. Consequently, the maximum liquid fuel penetration is 27 mm, which is short enough to avoid wall impingement. The cool flame starts 4.5 crank angle degrees (CAD) after the start of injection (ASI), midway between the injector and bowl-rim, and likely helps fuel to vaporize. Within a few CAD, the cool-flame combustion reaches the bowl-rim. A large premixed combustion occurs near 9 CAD ASI, close to the bowl rim. Soot is visible shortly afterwards along the walls, typically between two adjacent jets at the head vortex location. OH PLIF indicates that premixed combustion first occurs within the jet and then spreads along the bowl rim in a thin layer, surrounding soot pockets at the start of the mixing-controlled combustion phase near 17 CAD ASI. During the mixing-controlled phase, soot is not fully oxidized and is still present near the bowl-rim late in the cycle. At the end of combustion near 27 CAD ASI, averaged PLIF images indicate two separate zones. OH PLIF appears near the bowl rim, while broadband PLIF persists late in the cycle near the injector. The most likely source of broadband PLIF is unburned fuel, which indicates that the near-injector region is a potential source of unburned hydrocarbons.

scholarly journals Optical Diagnostics of Late-Injection Low-Temperature Combustion in a Heavy-Duty Diesel Engine

2008 ◽  
Vol 130 (3) ◽  
Author(s):  
Thierry Lachaux ◽  
Mark P. B. Musculus ◽  
Satbir Singh ◽  
Rolf D. Reitz
Keyword(s):  
Diesel Engine ◽  
Low Temperature ◽  
Liquid Fuel ◽  
Premixed Combustion ◽  
Low Temperature Combustion ◽  
Heavy Duty ◽  
Cool Flame ◽  
Heavy Duty Diesel Engine ◽  
Temperature Combustion ◽  
Heavy Duty Diesel

A late-injection, high exhaust-gas recirculation rate, low-temperature combustion strategy is investigated in a heavy-duty diesel engine using a suite of optical diagnostics: chemiluminescence for visualization of ignition and combustion, laser Mie scattering for liquid-fuel imaging, planar laser-induced fluorescence (PLIF) for both OH and vapor-fuel imagings, and laser-induced incandescence for soot imaging. Fuel is injected at top dead center when the in-cylinder gases are hot and dense. Consequently, the maximum liquid-fuel penetration is 27 mm, which is short enough to avoid wall impingement. The cool flame starts 4.5 crank angle degrees (CAD) after the start of injection (ASI), midway between the injector and bowl rim, and likely helps fuel to vaporize. Within a few CAD, the cool-flame combustion reaches the bowl rim. A large premixed combustion occurs near 9 CAD ASI, close to the bowl rim. Soot is visible shortly afterward, along the walls, typically between two adjacent jets. OH PLIF indicates that premixed combustion first occurs within the jet and then spreads along the bowl rim in a thin layer, surrounding soot pockets at the start of the mixing-controlled combustion phase near 17 CAD ASI. During the mixing-controlled phase, soot is not fully oxidized and is still present near the bowl rim late in the cycle. At the end of combustion near 27 CAD ASI, averaged PLIF images indicate two separate zones. OH PLIF appears near the bowl rim, while broadband PLIF persists late in the cycle near the injector. The most likely source of broadband PLIF is unburned fuel, which indicates that the near-injector region is a potential source of unburned hydrocarbons.

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