Internal combustion engine with an exhaust turbocharger and an exhaust-gas recirculation device
AssigneeDaimlerChrysler AG
InventorsWolfram Schmid, Siegfried Sumser
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Abstract
An internal combustion engine with an exhaust turbocharger and an exhaust-gas recirculation device comprises a turbine, assigned to the exhaust turbocharger, in the exhaust section and a compressor in the intake duct, the turbine having at least two flow passages, via which exhaust gas can be fed to the turbine rotor. For the purpose of dimensioning the two flow passages, an asymmetry factor is determined as a function of the displacement of the internal combustion engine.
Claims25
An internal combustion engine comprising:
- an exhaust turbocharger including,
- an exhaust turbine disposed in an exhaust section, the exhaust turbine having a choke line, a turbine rotor and two flow passages for feeding exhaust gas to the turbine rotor,
- a compressor in an intake duct, and
- an exhaust-gas recirculation device having a recirculation line disposed between one of the flow passages and the intake duct;
- and
- wherein an asymmetry factor (FAsym) defining the size ratio of the flow passages of the exhaust turbine satisfies the formula
- FAsym≦(1/VH)0.15
- wherein VH is the total displacement of the internal combustion engine, and wherein the asymmetry factor (FAsym) is defined as
- FAsym=φ31,S/φ32,S
- wherein φ31,S and φ32,S denote turbine throughput parameters in a region of the choke line of the exhaust turbine and are determined from the formula
- φ31,S=m31,S{square root over (T31,S)}/p31,S
- φ32,S=m32,S{square root over (T32,S)}/p32,S
- wherein
- m31,S, m32,S denote the mass flows of exhaust gas through the first and second flow passages, respectively, in the region of the choke line of the exhaust turbine,
- wherein T31,S, T32,S denote the exhaust-gas temperatures in the first and second flow passages, respectively, in the region of the choke line of the exhaust turbine, and
- wherein p31,S, p32,S denote the exhaust-gas pressures in the first and second flow passages, respectively, in the region of the choke line of the exhaust turbine.
A method of making an internal combustion engine that includes an exhaust turbocharger including an exhaust turbine disposed in an exhaust section, and a compressor disposed in an intake duct, wherein the exhaust turbine includes a choke line, a turbine rotor and two flow passages for feeding exhaust gas to the turbine rotor, wherein the engine further includes an exhaust-gas recirculation device having a recirculation line disposed between one of the flow passages and the intake duct, the method comprising:
- determining an asymmetry factor (FAsym), which defines the size ratio of the flow passages of the exhaust turbine, in accordance with the formula,
- FAsym≦(1/VH)0.15
- wherein VH is the total displacement of the internal combustion engine, and wherein the asymmetry factor (FAsym) is defined as
- FAsym=φ31,S/φ32,S
- wherein φ31,S and φ32,S denote turbine throughput parameters in a region of the choke line of the exhaust turbine and are determined from the formula
- φ31,S=m31,S{square root over (T31,S)}/p31,S
- φ32,S=m32,S{square root over (T32,S)}/p32,S
- wherein
- m31,S, m32,S denote the mass flows of exhaust gas through the first and second flow passages, respectively, in the region of the choke line of the exhaust turbine,
- wherein T31,S, T32,S denote the exhaust-gas temperatures in the first and second flow passages, respectively, in the region of the choke line of the exhaust turbine, and
- wherein p31,S, p32,S denote the exhaust-gas pressures in the first and second flow passages, respectively, in the region of the choke line of the exhaust turbine.
Dependencies are inferred from the claim text.