Effects of Intake Valve Closure Timing on Heavy-Duty Diesel Engine Performance

Abstract

Miller cycle engine can reduce pump loss of low-load range; however, engine performance of high-load range gets worse due to the decrease of air. Variable valve actuation system or high-boosting system is used to compensate the decrease of air, but the system costs high. In this study, intake valve closure (IVC) timing was investigated by simulation and experiment on heavy-duty diesel engine with single-turbocharger and with single-cam-profile. As a result, IVC timing at Bottom Dead Center reduced excess air ratio of high-speed range and reduced pump loss of low-load range while maintaining the engine performance of high-load range．