This content is not included in your SAE MOBILUS subscription, or you are not logged in.
Effects of Late Intake Valve Closing Timing on Thermal Efficiency and Emissions Based on a Two-stage Turbocharger Diesel Engine
ISSN: 0148-7191, e-ISSN: 2688-3627
Published April 08, 2013 by SAE International in United States
Annotation ability available
This paper investigated the effects of late intake valve closing timing (IVCT) and two-stage turbocharger systems matching based on partially premixed combustion strategy. Tests were performed on a 12-liter L6 heavy-duty engine at loads up to 10 bar BMEP at various speed. IVCT (where IVCT is -80°ATDC, -65°ATDC and -55°ATDC at 1300 rpm, 1600 rpm and 1900 rpm, respectively) lowered the intake and exhaust difference pressure, reducing pumping loss and improved the effective thermal efficiency by 1%, 1.5% and 2% at BMEP of 5 bar at 1300 rpm, 1600 rpm and 1900 rpm. For certain injection timings and EGR rate, it is found that a significant reduction in soot (above 30%) and NOx (above 70%) emissions by means of IVCT. This is due to that IVCT lowered effective compression ratio and temperature during the compression stroke, resulting in a longer ignition delay as the fuel mixed more homogeneous with the charge air ahead of ignition. At 1300 rpm, 10 bar BMEP, the effective thermal efficiency is slightly decreased by means of IVCT. However, at 1600 rpm, 1900 rpm 10 bar BMEP, the effective thermal efficiency is increased by employing IVCT. It is also owing to that the reduction of the pumping work. Above all, IVCT played an important role to make homogeneous distribution of the equivalence ratio Φ and reduced the pumping loss due to decrease in pressure difference of intake and exhaust.
CitationWu, B., Yu, H., Pak, P., Pei, Y. et al., "Effects of Late Intake Valve Closing Timing on Thermal Efficiency and Emissions Based on a Two-stage Turbocharger Diesel Engine," SAE Technical Paper 2013-01-0276, 2013, https://doi.org/10.4271/2013-01-0276.
- Onishi , S. , Jo , S. , Shoda , K. , Jo , P. et al. Active Thermo-Atmosphere Combustion (ATAC) - A New Combustion Process for Internal Combustion Engines SAE Technical Paper 790501 1979 10.4271/790501
- Kamimoto , T. and Bae , M. High Combustion Temperature for the Reduction of Particulate in Diesel Engines SAE Technical Paper 880423 1988 10.4271/880423
- Kitamura T , Ito T , Senda J et al. Mechanism of smokeless diesel combustion with oxygenated fuels based on the dependence of the equivalence ration and temperature on soot particle formation International Journal of Engine Research 2002 3 4 233 248
- Dec , J. A Conceptual Model of DI Diesel Combustion Based on Laser-Sheet Imaging* SAE Technical Paper 970873 1997 10.4271/970873
- Murata , Y. , Kusaka , J. , Daisho , Y. , Kawano , D. et al. Miller-PCCI Combustion in an HSDI Diesel Engine with VVT SAE Int. J. Engines 1 1 444 456 2009 10.4271/2008-01-0644
- Nevin , R. , Sun , Y. , Gonzalez D., M. , and Reitz , R. PCCI Investigation Using Variable Intake Valve Closing in a Heavy Duty Diesel Engine SAE Technical Paper 2007-01-0903 2007 10.4271/2007-01-0903
- Lee , B. , Filipi , Z. , Assanis , D. , and Jung , D. Simulation-based Assessment of Various Dual-Stage Boosting Systems in Terms of Performance and Fuel Economy Improvements SAE Int. J. Engines 2 1 1335 1346 2009 10.4271/2009-01-1471
- Su , W. , Lin , T. , and Pei , Y. A Compound Technology for HCCI Combustion in a DI Diesel Engine Based on the Multi-Pulse Injection and the BUMP Combustion Chamber SAE Technical Paper 2003-01-0741 2003 10.4271/2003-01-0741
- György , Sitkei 1974 “Heat Transfer and Thermal Loading in Internal Combustion Engines,” Akademiai Kaido Budapest
- Heywood , J.B. “Internal Combustion Engine Fundamentals” Mcgraw-Hill New York 1988 47
- Su WH and Yu WB Effects of mixing and chemical parameters on thermal efficiency in a partly premixed combustion diesel engine with near-zero emissions International Journal of Engine Research 438177
- Murata , Y. , Kusaka , J. , Odaka , M. , Daisho , Y. et al. Achievement of Medium Engine Speed and Load Premixed Diesel Combustion with Variable Valve Timing SAE Technical Paper 2006-01-0203 2006 10.4271/2006-01-0203