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 mainta
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.
대표청구항▼
1. 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
1. 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. 2. The method of claim 1, wherein each of the first and second compressor recirculation paths recirculate compressed airflow from downstream of a charge air cooler and upstream of an intake throttle to a compressor inlet. 3. The method of claim 2, wherein adjusting flow through each of the first compressor recirculation and second compressor recirculation paths includes adjusting one or more of a first on/off valve coupled in the first recirculation path and a second on/off valve coupled in the second recirculation path. 4. The method of claim 3, wherein the second lower flow recirculation path includes a flow restriction downstream of the second valve. 5. The method of claim 4, wherein the flow restriction is an orifice. 6. The method of claim 4, wherein the flow restriction is a venturi. 7. The method of claim 4, wherein the adjusting includes, during steady-state and transient conditions, estimating a desired throttle mass flow rate and adjusting an opening of the first valve and the second valve based on a difference between the throttle mass flow rate and the threshold flow rate. 8. The method of claim 7, wherein adjusting one or more of the first and second valves includes, selecting adjusting of each of the first and second valves when the difference is larger than a threshold difference, and selecting adjusting of one of the first and second valves when the difference is smaller than the threshold difference. 9. The method of claim 7, wherein adjusting one or more of the first and second valves includes, opening the first valve while closing the second valve during a first condition;opening the second valve while closing the first valve during a second condition;opening each of the first valve and the second valve during a third condition; andclosing each of the first valve and the second valve during a fourth condition. 10. The method of claim 6, further comprising, while flowing compressor flow through the second recirculation path, drawing vacuum at a neck of the venturi, and applying the drawn vacuum to a fuel vapor canister during purging conditions and/or to a brake booster during vehicle braking. 11. 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; andselecting 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. 12. The method of claim 11, wherein selecting based on the desired compressor recirculation rate includes estimating the throttle mass flow rate, calculating a surge constrained compressor flow rate based on the compressor surge limit, determining the desired compressor recirculation rate based on a difference between the surge constrained compressor flow rate and the throttle mass flow rate, and selecting a mode where compressor recirculation flow corresponds to the difference. 13. The method of claim 12, wherein the selecting further includes selecting during steady-state engine operating conditions before an indication of surge is received. 14. The method of claim 12, wherein the selecting is further based on a change in throttle mass flow rate during a transient engine operating condition. 15. The method of claim 11, wherein each of the first and second compressor recirculation paths recirculate compressed airflow from downstream of a charge air cooler and upstream of an intake throttle to a compressor inlet, and wherein the second recirculation path includes a flow restriction, the flow restriction including one of an orifice and a venturi. 16. The method of claim 15, wherein opening the second valve includes flowing compressed airflow through the second recirculation path at a lower flow rate and wherein opening the first valve includes flowing compressed airflow through the first recirculation path at a higher flow rate. 17. 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; anda controller with computer readable instructions for: during steady-state operating conditions, operating with one or more of the first and second valves closed; andin response to a transient change in airflow, operating with one or more of the first and second valves open; andselecting 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. 18. The system of claim 17, wherein the selecting includes, if the throttle mass flow rate is higher than the desired compressor flow rate, operating with only the second valve open, and if the throttle mass flow rate is lower than the desired compressor flow rate, operating with each of the first and second valves open. 19. The system of claim 17, wherein the controller includes further instructions for, during conditions when the second valve is open, while flowing compressed air through the second recirculation passage, drawing a vacuum at the venturi; and supplying the drawn vacuum to an engine vacuum consumption device.
연구과제 타임라인
LOADING...
LOADING...
LOADING...
LOADING...
LOADING...
이 특허에 인용된 특허 (21)
Fattic, Gerald Thomas; Walters, James E.; Sullivan, Michael Scott, Apparatus and method for smoothing of vehicle drivelines.
Brunemann, George; Brackney, Larry J.; Dollmeyer, Thomas A.; Song, B. Jerry; Barbieri, Michael G.; Lipinski, Matthew M.; Eberhard, Wayne, Condensation protection AECD for an internal combustion engine employing cooled EGR.
Pintauro Arthur C. ; Samuelson Donald R. ; Siedow Henri A., Continuously variable electrically actuated flow control valve for high temperature applications.
Richter Helmuth (Celle-Boge DEX), Feed of the exhaust gases from an internal-combustion engine to the rotor of a centripetal turbine of an exhaust gas tur.
Staroselsky Naum (Des Moines IA) Mirsky Saul (West Des Moines IA) Reinke Paul A. (Des Moines IA), Method and apparatus for preventing surge in a dynamic compressor.
Ossareh, Hamid-Reza; Rumpsa, Todd Anthony; Banker, Adam Nathan; Gerhart, Matthew John; McConville, Gregory Patrick; Xiao, Baitao, Methods and system for controlling compressor surge.
※ AI-Helper는 부적절한 답변을 할 수 있습니다.