Methods and systems for boost control
AssigneeFord Global Technologies, LLC
InventorsJoseph Norman Ulrey, Julia Helen Buckland
Life of this patent
Estimating the term…
Abstract
Methods and systems are provided for managing a compressor temperature using EGR to address surge and condensation. A variable mixture of cooled compressor recirculation flow and hot EGR is provided to a compressor inlet. A composition of the mixture is adjusted to maintain a compressor inlet temperature sufficiently warm so as to reduce ingestion of condensation, and a compressor outlet temperature sufficiently cold to be within component temperature limits with flow above the surge limit.
Claims20
A method of controlling a boosted engine, comprising:
- determining, via an electronic control unit, engine operating conditions including determining a required amount of compressor recirculation;
- adjusting one or more of a first valve in a compressor recirculation passage, and a second valve in an exhaust gas recirculation passage, to form a mixture of compressor recirculation flow from downstream of a charge air cooler with exhaust gas flow from the exhaust gas recirculation passage;
- and
- delivering the mixture to a compressor inlet.
A method for a boosted engine, comprising:
- estimating, via an electronic control unit, engine operating conditions based on air intake flow at at least one of a compressor inlet or a charge air cooler outlet indicating condensation and based on a compressor air intake flow indicating a surge condition;
- during a first condition, mixing compressor recirculation flow from downstream of a charge aft cooler with exhaust gas recirculation flow from an exhaust gas recirculation passage, flowing unobstructed from downstream of a turbine, in a first proportion responsive to a condensation threshold temperature;
- and
- during a second condition, mixing the compressor recirculation flow with the exhaust gas recirculation in a second, different proportion responsive to surge,
- adjusting one or more of a first valve in a compressor recirculation passage, and a second valve in a exhaust gas recirculation passage to control the mixing of flow into the engine during the first and second conditions.
An engine system, comprising:
- an engine including an intake throttle;
- a turbocharger including a compressor driven by a turbine;
- a temperature sensor coupled to the compressor;
- a charge air cooler coupled downstream of the compressor;
- a first path including a first valve for recirculating compressed aircharge from downstream of the charge air cooler and upstream of the throttle to a compressor inlet;
- a second path including a second valve for recirculating exhaust gas from downstream of the turbine to the compressor inlet, the second path merging with the first path downstream of the second valve and upstream of the compressor inlet;
- and
- a controller with computer readable instructions stored on a non-transitory medium for:
- receiving one or more of a compressor inlet temperature and a compressor outlet temperature from the temperature sensor;
- and
- sending a control signal to adjust each of the first and second valve to provide a variable mixture of compressor recirculation flow and exhaust gas recirculation to the compressor inlet, a composition of the variable mixture adjusted based on one or more of the compressor inlet temperature and the compressor outlet temperature.
Dependencies are inferred from the claim text.