Patent ID: 6725847
Filing Date: 2004-04-27
Classification: F02B,F02D,F02M,Y02T

Abstract:
System for protecting an internal combustion engine employing cooled recirculated exhaust gas from excessive condensation, the system comprising:an EGR conduit fluidly connecting an intake manifold with an exhaust manifold of the engine; an EGR valve controlling engine exhaust flow through the EGR conduit; an EGR valve position sensor producing an EGR valve position signal indicative of a position of the EGR valve relative to a reference position; an EGR valve actuator responsive to an actuator control signal to control the position of the EGR valve relative to the reference position; an EGR cooler disposed in-line with the EGR conduit and operable to cool engine exhaust flowing through the EGR conduit; means for determining a temperature value indicative of temperature within the intake manifold; and a control computer determining an amount of water present in a charge mixture of fresh air and engine exhaust supplied to the intake manifold and determining an intake condensation state as a function of the temperature value and of the amount of water present in the charge mixture, the control computer controlling the actuator control signal to close the EGR valve if the EGR valve position signal indicates that the EGR valve is positioned to allow engine exhaust flow through the EGR conduit and the condensation state indicates a condensation condition for at least a first time period.