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Effects of Engine Control Variables on Exhaust Gas Temperature and Stability during Cranking Operation of an SI Engine  

Cho, Yong-Seok (Department of Mechanical and Automotive Engineering)
An, Jae-Won (Graduated School of Automotive Engineering, Kookmin University)
Park, Young-Joon (Graduated School of Automotive Engineering, Kookmin University)
Kim, Duk-Sang (Graduated School of Automotive Engineering, Kookmin University)
Lee, Seang-Wock (Department of Mechanical and Automotive Engineering)
Publication Information
Transactions of the Korean Society of Automotive Engineers / v.15, no.1, 2007 , pp. 64-70 More about this Journal
Abstract
Raising exhaust gas temperature during cold-start period is very crucial to improve emission performance of SI engines because it enhances the performance of catalyst in the early stage of engine start. In this study, control variables such as ignition timing, idle speed actuator(ISA) opening and fuel injection duration were extensively investigated to analyze variations in exhaust gas temperature and engine stability during cranking period. Experimental results showed that spark timing affected engine stability and exhaust gas temperature but the effects were small. On the other hand, shortened injection duration and increased ISA opening led to a significant increase in exhaust gas temperature. Under such conditions, increase in cranking time was also observed, showing that it becomes harder to start the engine. Based on these observations, a pseudo fuel-air ratio, defined as a ratio of fuel injection time to degree of ISA opening, was introduced to analyze the experimental results. In general, decrease in pseudo fuel-air ratio raised exhaust gas temperature with the cost of stable and fast cranking. On the contrary, an optimal range of the pseudo fuel-air ratio was found to be between 0.3 to 0.5 where higher exhaust gas temperatures can be obtained without sacrificing the engine stability.
Keywords
Exhaust gas temperature; Injection duration; Idle speed actuator; Ignition timing; Engine start; Engine stability;
Citations & Related Records
Times Cited By KSCI : 1  (Citation Analysis)
연도 인용수 순위
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