An Investigation of the Potential of EGR stratification for Reducing Pressure Rise Rate in HCCI Combustion by using Rapid Compression Machine Keio Univ

Format:

Conference/Event

Author/Creator:

Odajima, Odajima, author.

Contributor:

Iida, Norimasa

Shirota, Daisuke

Conference Name:

SAE International Powertrains, Fuels and Lubricants Meeting (2011-08-30 : Kyoto, Japan)

Language:

English

Physical Description:

1 online resource

Place of Publication:

Warrendale, PA SAE International 2011

Summary:

HCCI (Homogeneous Charge Compression Ignition) engine is able toachieve low NOx and particulate emissions as well as highefficiency. However, its operation range is limited by the knockingat high load, which is the consequence of excessively rapidpressure rises. It has been suggested that making thermal or fuelinhomogeneities can be used to solve this problem, since theseinhomogeneities have proved to create different auto-ignitiontiming zones.It has also been suggested that EGR (Exhaust Gas Recirculation)has a potential to reduce pressure rise rate. But according to apast report, it was concluded that under the same fueling ratio andCA50 with different initial temperature and EGR ratio, the maximumPRR is almost constant.The purpose of this study is to investigate the fundamentaleffects of EGR. First, I considered EGR homogeneous charge case. Inthis case, the effects of EGR and its components like CO₂, H₂O orN₂ on HCCI combustion process is argued. When diluted with EGR orits components, gas composition changes and the ratio of heatcapacity and O₂ concentration become changed. As a consequence, thehistories of pressure and temperature, ignition timing andtemperature, combustion duration and PRR might be changed. So Ichecked them with addition of different amounts of EGR and itscomponents under the same fueling ratio, by using RCM (RapidCompression Machine). I used RCM to avoid influences such asin-cylinder gas temperature and fuel inhomogeneities. Second, Iconsidered EGR inhomogeneous case. In this case, I checked thosewhich are mentioned in homogeneous case with addition of same totalamounts of EGR but different amounts of EGR in each zones under thesame fueling ratio by using RCM. In these two cases, additionalnumerical calculation with single and multi-zones model is run toknow the potentials of EGR homogeneous and stratified charge, inorder to reduce PRR

Notes:

Vendor supplied data

Publisher Number:

2011-01-1762

Access Restriction:

Restricted for use by site license