Control of engine exhaust backpressure following engine cold-start
First Claim
1. A method of controlling a rate of warm-up of an internal combustion engine having a variable geometry turbocharger (VGT) including a compressor and a turbine with adjustable vanes fluidly connected to an exhaust system, the method comprising:
- identifying, via a controller, a cold-start of the engine;
regulating, via the controller, in response to the identified cold-start of the engine, an exhaust pressure modulation (EPM) valve arranged in a main exhaust passage of the exhaust system, wherein the main exhaust passage channels engine exhaust gas to the ambient, to restrict a flow of the engine exhaust gas to the ambient and increase exhaust gas backpressure in the main exhaust passage up to a predetermined pressure value to thereby increase a load on and the rate of warm-up of the engine;
regulating, via the controller, a low pressure exhaust gas recirculation (LPEGR) valve to selectively control flow of the engine exhaust gas through an LPEGR passage following said regulating the EPM valve in response to the identified cold-start of the engine,whereinthe LPEGR passage fluidly connects the main exhaust passage to the engine, andthe LPEGR valve is arranged in the LPEGR passage;
determining ambient temperature via a sensor; and
maintaining the LPEGR valve in a fully-closed state, via the controller, to minimize condensation of moisture in the exhaust gas at the turbine of the VGT when the ambient temperature has been determined to be below −
10 degrees Celsius.
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Accused Products
Abstract
A method of controlling a rate of warm-up of an internal combustion engine fluidly connected to an exhaust system is disclosed. The method includes identifying a cold-start of the engine. The method also includes regulating, in response to the identified cold-start of the engine, an exhaust pressure modulation (EPM) valve arranged in a main exhaust passage of the exhaust system. The main exhaust passage channels engine exhaust gas to the ambient. Such regulation of the EPM valve will restrict a flow of the engine exhaust gas to the ambient and increase exhaust gas backpressure in the exhaust system up to a predetermined pressure value. Furthermore, the subject regulation of the EPM valve will increase a load on and the rate of warm-up of the engine. A vehicle having an engine and a controller programmed to control a rate of the engine'"'"'s warm-up of according to the method is also disclosed.
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Citations
14 Claims
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1. A method of controlling a rate of warm-up of an internal combustion engine having a variable geometry turbocharger (VGT) including a compressor and a turbine with adjustable vanes fluidly connected to an exhaust system, the method comprising:
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identifying, via a controller, a cold-start of the engine; regulating, via the controller, in response to the identified cold-start of the engine, an exhaust pressure modulation (EPM) valve arranged in a main exhaust passage of the exhaust system, wherein the main exhaust passage channels engine exhaust gas to the ambient, to restrict a flow of the engine exhaust gas to the ambient and increase exhaust gas backpressure in the main exhaust passage up to a predetermined pressure value to thereby increase a load on and the rate of warm-up of the engine; regulating, via the controller, a low pressure exhaust gas recirculation (LPEGR) valve to selectively control flow of the engine exhaust gas through an LPEGR passage following said regulating the EPM valve in response to the identified cold-start of the engine, wherein the LPEGR passage fluidly connects the main exhaust passage to the engine, and the LPEGR valve is arranged in the LPEGR passage; determining ambient temperature via a sensor; and maintaining the LPEGR valve in a fully-closed state, via the controller, to minimize condensation of moisture in the exhaust gas at the turbine of the VGT when the ambient temperature has been determined to be below −
10 degrees Celsius. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. A vehicle comprising:
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an internal combustion engine; a variable geometry turbocharger (VGT) having a turbine with adjustable vanes and a compressor; an exhaust system fluidly connected to the engine and having a main exhaust passage configured to channel engine exhaust gas to the ambient; an exhaust pressure modulation (EPM) valve arranged in the main exhaust passage and configured to vary an exhaust backpressure in the main exhaust passage; a sensor configured to detect ambient temperature; a low pressure exhaust gas recirculation (LPEGR) passage fluidly connecting the main exhaust passage to the engine; an LPEGR valve arranged in the LPEGR passage; and a controller including executable instructions stored in a non-transitory medium to; identify a cold-start of the engine; regulate, in response to the identified cold-start of the engine, the EPM valve to restrict a flow of the engine exhaust gas to the ambient and increase exhaust gas backpressure in the main exhaust passage up to a predetermined pressure value to thereby increase a load on and the rate of warm-up of the engine; regulate the LPEGR valve to selectively control flow of the engine exhaust gas through an LPEGR passage following the regulation of the EPM valve in response to the identified cold-start of the engine; regulate the LPEGR valve to direct the exhaust gas to the compressor of the VGT following regulation of the EPM valve in response to the identified cold-start of the engine; determine ambient temperature; and maintain the LPEGR valve in a fully-closed state to minimize condensation of moisture in the exhaust gas at the turbine of the VGT when the ambient temperature has been determined to be below −
10 degrees Celsius. - View Dependent Claims (9, 10, 11, 12, 13, 14)
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Specification