Patent ID: 7971577
Filing Date: 2011-07-05
Classification: F01P,F02B,F02M,F28D,F28G

Abstract:
1. A method to recirculate an exhaust gas from an exhaust port of an engine to an intake of the engine via an exhaust-gas recirculation cooler, the engine and the exhaust-gas recirculation cooler sharing a coolant, the exhaust port coupled to an exhaust system, the method comprising: when a temperature of the coolant is above a threshold temperature, switchably flowing the exhaust gas through the exhaust-gas recirculation cooler according to a normal-calibration control mode; when a temperature of the coolant is below the threshold temperature, switchably flowing the exhaust gas through the exhaust-gas recirculation cooler according to an EGR-cooler restoring control mode, the EGR-cooler restoring control mode admitting a greater time-averaged flow of the exhaust gas through the exhaust-gas recirculation cooler when the temperature of the coolant is below the threshold temperature than does the normal-calibration control mode; and flowing the exhaust gas from the exhaust-gas recirculation cooler to the intake of the engine.