Methods and systems for surge control
AssigneeFord Global Technologies, LLC
InventorsJulia Helen Buckland, Robert Andrew Wade, Gregory Patrick McConville, Kevin Payne, Joseph Ulrey
Life of this patent
Estimating the term…
Abstract
Methods and systems are provided for recirculating compressed air across a compressor through a high flow and a low flow compressor recirculation path. Flow through the recirculation paths is controlled via respective valves and valve opening is adjusted based on a throttle mass flow so as to maintain a compressor flow rate at or above a surge constrained flow rate. By maintaining a sufficiently high compressor flow rate during steady state and transient conditions, the compressor state can be maintained outside a surge region.
Claims19
A method for a boosted engine, comprising:
- adjusting flow through each of a first higher flow compressor recirculation path and a second lower flow compressor recirculation path based on a throttle mass flow rate to maintain a compressor flow rate at or above a threshold flow rate, estimating the threshold flow rate based on a compressor surge limit, and the second recirculation path positioned in parallel to the first recirculation path.
A method for a boosted engine, comprising:
- operating in a first mode with a first valve coupled to a first compressor recirculation path open and a second valve coupled to a second compressor recirculation path closed, the second recirculation path positioned in parallel to the first recirculation path;
- operating in a second mode with the first valve closed and the second valve open;
- operating in a third mode with each of the first and second valves open;
- operating in a fourth mode with each of the first and second valves closed;
- and
- selecting between the modes based on a desired compressor recirculation flow rate, wherein the desired compressor recirculation flow rate is based on a throttle mass flow rate and a compressor surge limit.
An engine system, comprising:
- an engine including an intake manifold;
- a throttle coupled to the intake manifold;
- a sensor coupled to the intake manifold for estimating a manifold air flow;
- a compressor for compressing aircharge delivered to the intake manifold;
- a charge air cooler coupled downstream of the compressor and upstream of the throttle;
- a first compressor recirculation passage coupling an outlet of the charge air cooler to an inlet of the compressor, the first recirculation passage including a first valve;
- a second compressor recirculation passage parallel to the first recirculation passage and coupling the charge air cooler outlet to the compressor inlet, the second recirculation passage including a second valve and a venturi located downstream of the second valve;
- and
- a controller with computer readable instructions for:
- during steady-state operating conditions,
- operating with one or more of the first and second valves closed;
- and
- in response to a transient change in airflow,
- operating with one or more of the first and second valves open;
- and
- selecting one or more of the first and second valves to open based on a throttle mass flow rate and a desired compressor flow rate, the throttle mass flow rate based on the sensor, the desired compressor flow rate based on a surge limit of the compressor.
Dependencies are inferred from the claim text.