Journal of ILASS-Korea (한국분무공학회지)

Institute for Liquid Atomization and Spray Systems-Korea (한국분무공학회)
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Effect of Controlling Exhaust Valve Timing on Engine Efficiency in LIVC and EIVC States in a 2-Cylinder Small Turbo Gasoline Engine

2기통 소형 터보가솔린엔진에서 배기 밸브 타이밍 제어에 따른 LIVC, EIVC 상태에서의 엔진 효율 영향

  • Received : 2022.06.20
  • Accepted : 2022.07.12
  • Published : 2022.09.30
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Abstract

This study examines whether engine fuel efficiency is improved by optimization of the exhaust valve timing in a state where the intake valve timing has been optimized in a small turbo gasoline engine that has intake cams and exhaust cams with fixed valve opening periods. When the exhaust valve is opened late, the expansion stroke is longer, and the efficiency can be improved. A 2-cylinder turbo gasoline engine with 0.8 liters of displacement and an MPI (Multi Point Injection) fuel system was used. The engine was operated at 1,500 and 3,000 rpm, and the load conditions included a partial load of 50 N·m and a high load of 70 N·m. Data was recorded as the exhaust valve timing was controlled, and this was used to calculate the efficiency of combustion using a heat release, the fuel conversion efficiency, and the pumping loss. Results and the hydrocarbon concentrations in the exhaust gas were compared for each condition. Experiment results confirmed that additional fuel efficiency improvements are possible through exhaust valve timing control at 1,500 rpm and 50 N·m. However, in other operating conditions, fuel efficiency improvements could not be obtained through exhaust valve timing control because cases where the pumping loss and fuel/air mixture slip increased when the exhaust valve timing changed and the fuel efficiency declined.

Keywords

Acknowledgement

본 연구는 환경부 Global-Top Project 친환경자동차기술개발사업단의 지원에 의해 수행되었으며 이에 감사드립니다.

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