Method and control system of a supercharged spark-ignition internal combustion engine configured to purge a charge air cooler

Abstract

Method (100) of controlling a supercharged spark-ignition internal combustion engine (10) comprising a heat exchanger mounted downstream of a compressor of a supercharging system and a variable valve timing system (27) configured to control the valve lift (VVT) between exhaust bottom dead center (BDC exhaust), top dead center (TDC) and intake bottom dead center (BDC intake), wherein:- the mass (M_water) of liquid water stored in real time on internal walls of the exchanger (26) is estimated;- said estimated mass (M_water) is compared with a threshold value (S); and- the purge of the cooler (26) is activated when the estimate of the mass of water (M_water) is greater than the threshold value (S), by generating oscillations of the volumetric flow rate of intake air (Qvol) entering the exchanger (26) between a nominal volumetric flow rate value (Qvol_nom) and an increased flow rate value (Qvol_+).Figure for the abridged version: Fig 6.

Claims

upper crossover (CVVT_+), for example between 30°Vil and 60°Vil, preferably equal to 60°Vil, when the engine operates in supercharged mode and between a nominal crossover value (CVVT_nom) and a reduced crossover value (CVVT_-), for example equal to 0°Vil when the engine operates in non-supercharged mode.

11. A motor vehicle comprising an electronic control unit according to any one of claims 8 to 10. [Fig. 2a] Valve lift ■without offset WT fWÏÛ / û) [Fig. 2b] Valve lift with WT offset (eg: WT20 / 20) Crossing = 4(FV0 FMB II ; , t II exhaust Crossing = 40' Vil p^g admission WT Crossing Zone [Fig. 3] Yield wlümétnque of Intake pressure œfedenr < Exhaust pressure cotectear [Fig. 4a] [Fig. 5]

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