Exhaust gas recirculation cooler protection system and method

A system for operating an exhaust gas recirculation (EGR) system of a vehicle including an engine configured to receive intake air from an intake conduit and to output exhaust gas to an exhaust conduit, the system comprising:

• an EGR circuit including an EGR valve and an EGR cooler;
• wherein the EGR valve is actuable between an enabled position and a disabled position;
• wherein with the EGR valve actuated to the enabled position, the EGR circuit is in fluid communication with the intake conduit and the exhaust conduit such that a portion of the exhaust gas from the exhaust conduit is recirculated through the EGR circuit, the EGR valve and the EGR cooler to the intake conduit;
• wherein with the EGR valve actuated to the disabled position the exhaust gas is prevented from recirculation through the EGR circuit;
• a controller configured to:
• receive an input from each of an engine speed sensor, a vehicle speed sensor, an outside ambient temperature sensor, and a commanded fuel sensor;
• integrate the inputs received from the engine speed sensor, the vehicle speed sensor, the outside ambient temperature sensor, and the commanded fuel sensor to predict an EGR coolant temperature;
• compare the predicted EGR coolant temperature to an EGR coolant temperature threshold;
• actuate the EGR valve to the EGR disabled position when the predicted EGR coolant temperature is equal or greater than the EGR coolant temperature threshold;
• and
• actuate the EGR valve to the EGR enabled position when the predicted EGR coolant temperature is less than the EGR coolant temperature threshold.

A tangible, non-transitory computer-readable medium having instructions stored thereon that when executed by a processor perform a method for operating an exhaust gas recirculation (EGR) system of a vehicle, the method comprising:

• measuring an engine speed, a vehicle speed, an outside ambient temperature, and a commanded fuel level of the vehicle;
• controlling an EGR valve, wherein the EGR valve is actuable between an EGR enabled position and an EGR disabled position;
• wherein with the EGR valve in the EGR enabled position a portion of exhaust gas emitted from an engine of the vehicle is directed through an EGR cooler for recirculation into the engine;
• wherein with the EGR valve in the EGR disabled position the exhaust gas emitted from the engine is diverted from the EGR cooler such that the exhaust gas is not recirculated through the engine;
• wherein controlling the EGR valve further comprises:
• predicting an EGR coolant temperature from the measured engine speed, vehicle speed, outside ambient temperature, and commanded fuel level;
• comparing the predicted EGR coolant temperature to an EGR coolant temperature threshold;
• actuating the EGR valve to the EGR disabled position when the predicted EGR coolant temperature is greater than the EGR coolant temperature threshold;
• and
• actuating the EGR valve to the EGR enabled position when the predicted EGR coolant temperature is equal to or less than the EGR coolant temperature threshold.