System and method for estimating EGR mass flow and EGR fraction
First Claim
1. A system for estimating EGR mass flow, comprising:
- an exhaust gas recirculation (EGR) conduit fluidly coupling an intake manifold of an internal combustion engine to an exhaust manifold of said engine, said EGR conduit including a flow restrictor disposed between said exhaust manifold and said intake manifold;
means for determining a pressure differential across said flow restrictor;
means for determining a gas density value corresponding to a density of gas flowing through said flow restrictor;
means for determining an effective flow area of said flow restrictor; and
a control circuit determining a mass flow of EGR through said EGR conduit based on said pressure differential, said gas density value and said effective flow area.
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Accused Products
Abstract
A system is disclosed for estimating the mass flow of recirculated exhaust gas (EGR) from an exhaust manifold to an intake manifold of an internal combustion engine via an EGR conduit disposed therebetween and a fraction of EGR attributable to a mass of charge flow entering the intake manifold. An engine controller is responsive to current values of various combinations of the engine exhaust temperature (ETE), intake manifold pressure (IMP), differential pressure (ΔP) across an EGR valve, and EGR valve position (EGRP) to determine an estimate of EGR mass flow. The controller is further operable to estimate EGR fraction as a function of the estimated EGR mass flow value, mass flow of charge entering the intake manifold, and engine speed.
56 Citations
34 Claims
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1. A system for estimating EGR mass flow, comprising:
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an exhaust gas recirculation (EGR) conduit fluidly coupling an intake manifold of an internal combustion engine to an exhaust manifold of said engine, said EGR conduit including a flow restrictor disposed between said exhaust manifold and said intake manifold;
means for determining a pressure differential across said flow restrictor;
means for determining a gas density value corresponding to a density of gas flowing through said flow restrictor;
means for determining an effective flow area of said flow restrictor; and
a control circuit determining a mass flow of EGR through said EGR conduit based on said pressure differential, said gas density value and said effective flow area. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22)
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23. A system for estimating EGR mass flow, comprising:
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an exhaust gas recirculation (EGR) conduit fluidly coupling an intake manifold of an internal combustion engine to an exhaust manifold thereof, said EGR conduit including an EGR valve disposed between said exhaust manifold and said intake manifold;
an EGR valve position sensor producing a position signal indicative of EGR valve position relative to a reference position;
means for determining a pressure differential between said exhaust and intake manifolds; and
a control circuit determining EGR mass flow through said EGR conduit based on said position signal and said pressure differential. - View Dependent Claims (24, 25, 26)
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27. A system for estimating EGR mass flow, comprising:
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an exhaust gas recirculation (EGR) conduit fluidly coupling an intake manifold of an internal combustion engine to an exhaust manifold thereof, said EGR conduit including an EGR valve disposed between said exhaust manifold and said intake manifold;
an EGR valve position sensor producing a position signal indicative of EGR valve position relative to a reference position;
means for determining a pressure ratio between said exhaust and intake manifolds;
means for determining a temperature of exhaust gas produced by said engine and producing a temperature value corresponding thereto; and
a control circuit determining EGR mass flow through said EGR conduit based on said position signal, said pressure ratio and said temperature value. - View Dependent Claims (28, 29, 30, 31, 32, 33, 34)
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Specification