Avoidance of coolant overheating in exhaust-to-coolant heat exchangers
AssigneeFord Global Technologies, LLC
InventorsRoss Dykstra Pursifull, Gopichandra Surnilla
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Abstract
A method for operating an engine system comprises charging a cylinder of the engine system with exhaust from upstream of an exhaust turbine at a first rate. The method further comprises charging the cylinder with exhaust from downstream of the turbine at a second rate. The exhaust from downstream of the turbine is routed to the cylinder via a low-pressure exhaust-gas recirculation path. The method further comprises increasing the second rate relative to the first rate in response to a coolant-overheating condition.
Claims21
A method for operating an engine system having a cylinder, an exhaust turbine and an intake-air compressor, the method comprising:
- charging the cylinder with exhaust from upstream of the turbine at a first rate;
- charging the cylinder with exhaust from downstream of the turbine at a second rate via an external low-pressure (LP) exhaust-gas recirculation (EGR) path;
- and
- increasing the second rate relative to the first rate in response to a coolant-overheating condition.
A method for operating an engine system having an intake-air compressor and a charge-air cooler coupled downstream of the intake-air compressor, the method comprising:
- reducing torque applied to the compressor in response to a coolant-overheating condition;
- and
- maintaining or increasing a coolant flow to the charge-air cooler when the torque is reduced in response to the coolant-overheating condition.
A method for operating an engine system having a cylinder, an exhaust turbine and an intake-air compressor, the method comprising:
- charging the cylinder with exhaust from upstream of the turbine at a first rate;
- charging the cylinder with exhaust from downstream of the turbine at a second rate via an external low-pressure (LP) exhaust-gas recirculation (EGR) path;
- detecting a coolant-overheating condition;
- increasing the second rate relative to the first rate in response to the coolant-overheating condition;
- reducing the torque applied to the compressor if the coolant-overheating condition persist after the second rate is increased relative to the first rate;
- and
- maintaining or increasing a coolant flow to the charge-air cooler when the torque is reduced in response to the coolant-overheating condition.
Dependencies are inferred from the claim text.