System and method for relieving engine back-pressure by selectively bypassing a stage of a two-stage turbocharger during non-use of EGR
First Claim
1. A control system for an internal combustion engine that has an intake system including a turbocharger compressor for developing combustion charge air for the engine, combustion chambers where charge air and fuel are combusted to operate the engine, an exhaust system through which exhaust gas resulting from combustion pass from the combustion chambers, including a turbocharger turbine that uses exhaust gas to operate the turbocharger compressor, an EGR system for recirculating some exhaust gas from the exhaust system to the intake system, and a valve for selectively shunting exhaust gas around a stage of the turbine, the control system comprising:
- a processor for processing data to selectively render the EGR system active and inactive and to develop a value for a set-point of operation for the valve defining the extent to which the valve shunts exhaust gas around the turbine stage, a first map set containing set-point data based on the EGR system being active and a second map set containing set-point data based on the EGR system being inactive, wherein the processor processes data selected from the first map set and not from the second map set to develop the set-point value when the EGR system is active, and processes data selected from the second map set and not from the first map set to develop the set-point value when the EGR system is inactive.
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Accused Products
Abstract
A valve (50) selectively shunts exhaust gas around a stage (20T) of a turbocharger turbine (20) under control of a control system that selectively renders an EGR system (38) active and inactive and that develops a value for a set-point of operation for the valve. The control system comprises a first map set (60, 142) containing data that the control system uses to the exclusion of data in a second map set (80, 148) to develop the set-point value when the EGR system is active. When the EGR system is inactive, the control system uses the data in the second map set to the exclusion of the data in the first map set to develop the set-point value.
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Citations
15 Claims
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1. A control system for an internal combustion engine that has an intake system including a turbocharger compressor for developing combustion charge air for the engine, combustion chambers where charge air and fuel are combusted to operate the engine, an exhaust system through which exhaust gas resulting from combustion pass from the combustion chambers, including a turbocharger turbine that uses exhaust gas to operate the turbocharger compressor, an EGR system for recirculating some exhaust gas from the exhaust system to the intake system, and a valve for selectively shunting exhaust gas around a stage of the turbine, the control system comprising:
a processor for processing data to selectively render the EGR system active and inactive and to develop a value for a set-point of operation for the valve defining the extent to which the valve shunts exhaust gas around the turbine stage, a first map set containing set-point data based on the EGR system being active and a second map set containing set-point data based on the EGR system being inactive, wherein the processor processes data selected from the first map set and not from the second map set to develop the set-point value when the EGR system is active, and processes data selected from the second map set and not from the first map set to develop the set-point value when the EGR system is inactive. - View Dependent Claims (2, 3, 4, 5)
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6. An internal combustion engine comprising:
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an intake system including a turbocharger compressor for developing combustion charge air for the engine; combustion chambers where charge air and fuel are combusted to operate the engine; an exhaust system through which exhaust gas resulting from combustion pass from the combustion chambers, including a turbocharger turbine that uses exhaust gas to operate the turbocharger compressor; an EGR system for recirculating some exhaust gas from the exhaust system to the intake system; a valve for selectively shunting exhaust gas around a stage of the turbine; and a control system for selectively rendering the EGR system active and inactive and for developing a value for a set-point of operation for the valve defining the extent to which the valve shunts exhaust gas around the turbine stage, wherein the control system comprises a first map set containing data that the control system uses to the exclusion of data in a second map set to develop the set-point value when the EGR system is active and the control system uses the data in the second map set to the exclusion of the data in the first map set to develop the set-point value when the EGR system is inactive. - View Dependent Claims (7, 8, 9, 10, 11)
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12. A method for control of a turbocharger in an internal combustion engine that has an intake system including a compressor of the turbocharger for developing combustion charge air for the engine, combustion chambers where charge air and fuel are combusted to operate the engine, an exhaust system through which exhaust gas resulting from combustion pass from the combustion chambers, including a turbine of the turbocharger operated by exhaust gas to operate the compressor, an EGR system for recirculating some exhaust gas from the exhaust system to the intake system, and a device for selectively utilizing exhaust gas to operate the turbine, the method comprising:
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processing data to selectively render the EGR system active and inactive and to develop a value for a set-point of operation for the turbocharger defining the extent to which exhaust gas is utilized to operate the turbine; processing data to select from a first map set containing set-point data based on the EGR system being active, a set-point data value correlated with current engine speed and engine load and further processing the selected set-point data value from the first map when the EGR system is active to develop the set-point of operation for the turbocharger; and processing data to select from a second map set containing set-point data based on the EGR system being inactive, a set-point data value correlated with current engine speed and engine load and further processing the selected set-point data value from the second map when the EGR system is inactive to develop the set-point of operation for the turbocharger. - View Dependent Claims (13, 14, 15)
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Specification