Patent attributes
An exhaust gas recirculation (EGR) system is provided for an internal combustion engine having a combustion air intake circuit, an exhaust manifold, and an exhaust circuit for communicating engine exhaust to the environment. The EGR system includes an air-to-gas EGR cooler, an air supply conduit for supplying inlet air to the EGR cooler, an EGR supply conduit for communicating exhaust from the exhaust circuit to the EGR cooler, and an EGR outlet conduit communicating cooled EGR from the EGR cooler to the intake circuit. The EGR system also includes a venturi unit in the exhaust circuit, and an air outlet conduit communicating heated air from the EGR cooler to the venturi unit. Flow of exhaust through the venturi creates a pressure which draws cooling air through the EGR cooler. A valve controls flow through the outlet conduit as a function of a sensed temperature in the intake circuit.
