Dual core exhaust gas recirculation cooler

A dual core exhaust gas recirculation (EGR) cooler comprising:

• a cooler housing having a first end, a second end opposite the first end, and sides spanning the first and second ends, the cooler housing having an EGR inlet at the first end of the cooler housing, a first EGR outlet intermediate the first end and the second end of the cooler housing, a second EGR outlet at the second end of the cooler housing, a coolant inlet and a coolant outlet;
• a cooling circuit extending from the coolant inlet through the cooler housing to the coolant outlet;
• a first EGR circuit core extending through the cooler housing from the EGR inlet to the first EGR outlet, the first EGR circuit core having a first plurality of tubes extending in a direction from the first end to the second end of the cooler housing;
• a second EGR circuit core extending through the cooler housing to the second EGR outlet from the EGR inlet or the first EGR outlet, the second EGR circuit core having a second plurality of tubes extending in the direction from the first end to the second end of the cooler housing;
• a first EGR valve configured to selectively couple the first EGR circuit core to a return passageway through the first EGR outlet;
• a second EGR valve configured to selectively couple the second EGR circuit core to the return passageway through the second EGR outlet;
• and
• a controller having processing architecture for executing instructions to control the first and second EGR valves;
• wherein the controller is configured to control the first and second EGR valves selectively flow EGR exhaust gas through the cooler housing from the EGR inlet to the return passageway within either the first EGR circuit core only or within both the first EGR circuit core and the second EGR circuit core;
• wherein when the controller controls the first EGR valve to open and the second EGR valve to close all the EGR exhaust gas flows through the cooler housing to the return passageway within the first EGR circuit core and not the second EGR circuit core;
• wherein when the controller controls the first EGR valve to close and the second EGR valve to open all the EGR exhaust gas flows through the cooler housing to the return passageway within the first EGR circuit core and the second EGR circuit core;
• and
• wherein when the controller controls the first EGR valve to open and the second EGR valve to open:
• a first portion of the EGR exhaust gas flows through the cooler housing to the return passageway within the first EGR circuit core only;
• and
• a second portion of the EGR exhaust gas flows through the cooler housing to the return passageway within the first EGR circuit core and the second EGR circuit core;
• wherein the first portion of the EGR exhaust gas, at a first temperature, mixes with the second portion of the EGR exhaust gas, at a second temperature, within the return passageway.