CO2 Emission Reduction Synergies of Advanced Engine Design and Fuel Octane Number BP International Limited

Format:

Conference/Event

Author/Creator:

Leach, Leach, author.

Contributor:

Ali, Rana

Pearson, Richard

Williams, John

Conference Name:

SAE 2014 International Powertrain, Fuels & Lubricants Meeting (2014-10-20 : Birmingham, United Kingdom)

Language:

English

Physical Description:

1 online resource

Place of Publication:

Warrendale, PA SAE International 2014

Summary:

Engine downsizing is a key approach employed by many vehicle manufacturers to help meet fleet average CO2 emissions targets. With gasoline engines in particular reducing engine swept volume while increasing specific output via technologies such as turbocharging, direct injection (DI) and variable valve timing can significantly reduce frictional and pumping losses in engine operating areas commonly encountered in legislative drive cycles.These engines have increased susceptibility to abnormal combustion phenomena such as knock due to the high brake mean effective pressures which they generate. This ultimately limits fuel efficiency benefits by demanding use of a lower geometric compression ratio and sub-optimal late combustion phasing at the higher specific loads experienced by these engines. The lower expansion ratio and retarded combustion in turn increase the exhaust gas temperature, which often leads to a need to add extra fuel that cannot be fully combusted in order to cool and protect engine components from thermal damage. Optimizing the engine design for use with a fuel with an increased research octane number (RON) allows the adoption of a higher compression ratio. This gives thermodynamic efficiency benefits at lower loads whilst mitigating the compromise in combustion phasing at high loads and reducing the requirement for over-fuelling. These synergies allow reductions in CO2 emissions and fuel consumption in both legislative drive cycles and real world driving.To quantify the benefits of such an approach a prototype 1.2l 3-cylinder turbocharged gasoline engine with a maximum BMEP of 30 bar was installed on an engine test bed and its operation optimised across a range of compression ratios and fuel octane numbers. For each combination of compression ratio and fuel octane number full operating area maps of fuel consumption, key combustion parameters and exhaust emissions were developed and are analyzed here.The key findings were:

Notes:

Vendor supplied data

Publisher Number:

2014-01-2610

Access Restriction:

Restricted for use by site license