EGR Cooler Defouling
AssigneeFord Global Technologies, LLC
InventorsDaniel Joseph Styles, David Curtis Ives
Life of this patent
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Abstract
A method to dislodge an adherent residue in an EGR cooler, the EGR cooler installed in an engine. The method comprises flowing an exhaust gas through an adherent-residue bearing surface of the EGR cooler when a temperature of the adherent-residue bearing surface is below a dewpoint temperature of the exhaust gas, enabling water vapor from the exhaust gas to condense on the adherent-residue bearing surface, heating the adherent-residue bearing surface to above the dewpoint temperature of the exhaust gas, and enabling condensed water on the adherent-residue bearing surface to evaporate. Other embodiments provide a method to recirculate an exhaust gas from an exhaust port of an engine to an intake of the engine via an EGR cooler, and a related EGR system.
Claims20
A method to dislodge an adherent residue in an exhaust-gas recirculation cooler, the exhaust-gas recirculation cooler installed in an engine, the method comprising:
- flowing an exhaust gas through an adherent-residue bearing surface of the exhaust-gas recirculation cooler when a temperature of the adherent-residue bearing surface is below a dewpoint temperature of the exhaust gas
- condensing water vapor from the exhaust gas on the adherent-residue bearing surface;
- heating the adherent-residue bearing surface to above the dewpoint temperature of the exhaust gas;
- and
- evaporating condensed water on the adherent-residue bearing surface.
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 a 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.
An exhaust-gas recirculation system, comprising:
- an exhaust-gas recirculation cooler configured to transmit heat from an exhaust gas to a first coolant;
- a valve configured to switchably admit the exhaust gas to the exhaust-gas recirculation cooler;
- a temperature sensor responsive to a temperature of the first coolant;
- a controller operatively coupled to the temperature sensor and to the valve, and configured to actuate the valve to switchably admit the exhaust gas to the exhaust-gas recirculation cooler at least when the temperature of the first coolant is below a threshold temperature.
Dependencies are inferred from the claim text.