Exploration of carbon deposit on spark plug of stratified charged gasoline direct injection engine

ABSTRACT

Gasoline direct injection (GDI) engines are operating under high temperature and hence fouling of spark plug can cause misfiring followed by carbon deposits in the vicinity of the spark plug. This effect can cause declined engine power output, unburned hydrocarbon emission and also unacceptable high NO_x near the lean flammability limit of gasoline. The objective was to explore carbon deposit on the spark plug and to identify the most suitable operating variable for the stratified charge mode of a GDI. Performance study was conducted on GDI engine on Start of Injection (SOI) angles of 60°, 100° and 140° bTDC with spark advance of MBT of 16°, 18° and 20°, respectively. Carbon deposit on spark plug at each injection angle was studied through scanning electron microscope (SEM) analysis at specified fuel air ratio. It was revealed that from performance and SEM analysis SOI 100° was chosen as the most suitable operating variable for the stratified charged GDI engine operation.

KEYWORDS:

• Gasoline direct injection
• carbon deposits
• combustion characteristics

Acknowledgement

The authors extend their heartfelt thanks to the authorities of the Engine Research Laboratory, Department of Mechanical Engineering, Annamalai University for permitting them to utilise the facility of engine test system for this work.

Disclosure statement

No potential conflict of interest was reported by the authors.