High Efficiency and Low Pollutants Combustion: Gasoline Multiple Premixed Compression Ignition (MPCI) Tsinghua Univ

Format:

Conference/Event

Author/Creator:

Yang, Yang, author.

Contributor:

Shuai, Shi-Jin

Wang, Jian-Xin

Wang, Zhi

Conference Name:

SAE 2012 World Congress & Exhibition (2012-04-24 : Detroit, Michigan, United States)

Language:

English

Physical Description:

1 online resource

Place of Publication:

Warrendale, PA SAE International 2012

Summary:

A new combustion mode namely multiple premixed compressionignition (MPCI) for gasoline engines was proposed. The MPCI modecan be realized by two or more times gasoline injections intocylinder with a high pressure around the compression TDC andfeatured with a premixed combustion after each injection in thecylinder, which is different from the existed gasoline directinjection compression ignition (GDICI) modes such as homogeneouscharge compression ignition (HCCI) mode with gasoline injectionoccurred in intake stroke, and partially premixed compressionignition (PPCI) mode with multiple gasoline injections in intakeand compression strokes before the start of combustion (SOC).Therefore the spray and combustion of the MPCI mode arealternatively occurred as"spray-combustion-spray-combustion" near the TDC, ratherthan "spray-spray-combustion" sequence as traditionalPPCI gasoline engines. Since the combustion process of the MPCImode is mainly controlled by the multiple gasoline injections, theSOC and pressure rise rate (PRR) can be controlled easily andeffectively through injection timing, injection split ratio andnumber of the injections. It is expected that each premixedcombustion process in the MPCI engine can be realized in the centerof combustion chamber with pure air filling the gap between thecombustion area and the cylinder wall, resulting in not only thelow PM and NOx emissions, but also the low THC and CO emissionswhile remaining the high thermal efficiency.The experimental study for the MPCI gasoline engine is carriedout on a single-cylinder compression ignition engine retrofittedfrom a four-cylinder light-duty diesel engine with the compressionratio of 18.5. A stable and moderate two-stage gasoline MPCI modeis achieved under the running conditions of 0.8 MPa IMEP load and1400 r/min speed at 70°C intake temperature without EGR and intakeboosting using the gasoline fuel with the research octane number of94.4. The NO and soot emissions as well as THC and CO arerelatively low, while keeping the indicated thermal efficiencyaround 40%, which cannot be easily reached with even diesel fuelunder the same conditions. However, optimization for the gasolineMPCI combustion mode is still needed in order to improve the fuelefficiency further. The test results show that the MPCI mode is apromising and feasible combustion mode for gasoline enginesachieving both of the high efficiency and low emissions especiallyat high load

Notes:

Vendor supplied data

Publisher Number:

2012-01-0382

Access Restriction:

Restricted for use by site license