Study of Intake Charge Control Method on TGDI Engine with CVVL System

摘要

(1) There are best Psr on all operating points for TGDI engine with CVVL system, at which lowest BSFC and relatively optimal emissions both are achieved at the same time. (2) The combination of intake valve lift and throttle opening is the best charge control method at low to middle loads when Rip is smaller than 0.95. Intake valve lift is the dominant control method and throttle opening is assistance method to achieve best Psr. (3) Throttle opening is the main charge control method when intake valve lift reaches 8.64 mm, the maximum lift position, till Rip exceeds 0.95. (4) The combination of turbocharger and throttle opening is the best charge control method on high loads after Rip exceeds 0.95. Turbocharger is the dominant control method and throttle opening is assistance method to ensure Rip greater than 0.95. (5) Turbocharger pressure is the sole charge control method after throttle is fully opened and Rip reaches 1. This work gives a design foundation for control software functions development of CVVL engine and helps improving CVVL engine control quality and calibration efficiency.