Effects of Variable Inlet Valve Timing and Swirl Ratio on Combustion and Emissions in a Heavy Duty Diesel Engine Volvo Group Truck Technology

Format:

Conference/Event

Author/Creator:

Ehleskog, Ehleskog, author.

Contributor:

Denbratt, Ingemar

Gjirja, Savo

Conference Name:

SAE 2012 International Powertrains, Fuels & Lubricants Meeting (2012-09-18 : Malmo, Sweden)

Language:

English

Physical Description:

1 online resource

Place of Publication:

Warrendale, PA SAE International 2012

Summary:

In order to avoid the high CO and HC emissions associated withlow temperature when using high levels of EGR, partially premixedcombustion is an interesting possibility. One way to achieve thiscombustion mode is to increase the ignition delay by adjusting theinlet valve closing timing, and thus the effective compressionratio.The purpose of this study was to investigate experimentally thepossibilities of using late and early inlet valve closure to reduceNOx emissions without increasing emissions of soot orunburned hydrocarbons, or fuel consumption. The effect ofincreasing the swirl number (from 0.2 to 2.5) was alsoinvestigated. The combustion timing (CA50) was kept constant byadjusting the start of injection and the possibilities ofoptimizing combustion using EGR and high injection pressures wereinvestigated. Furthermore, the airflow was kept constant for agiven EGR level.The engine used in the experiments was a single-cylinderheavy-duty direct injection diesel engine equipped with anelectronically controlled unit injector with variable needleopening pressure. Its geometry is based on the Volvo D12Cproduction engine with the compression ratio lowered from 18.5 to17. The engine is also equipped with a fully flexible pneumaticinlet valve system, enabling both early and late inlet valveclosing times and varied swirl levels.The results show that late or early IVC can be used to achievepartially premixed combustion (and thus low soot and NOxemissions) without a fuel consumption penalty

Notes:

Vendor supplied data

Publisher Number:

2012-01-1719

Access Restriction:

Restricted for use by site license