METHOD FOR THE CORRECTION OF THE REDUCED MASS FLOW RATE OF A COMPRESSOR IN AN INTERNAL COMBUSTION ENGINE TURBOCHARGED BY MEANS OF A TURBOCHARGER

摘要

A method for correcting the reduced mass flow rate of a compressor in an internal combustion engine turbocharged by means of a turbocharger provided with a turbine and with a compressor; the internal combustion engine comprising an intake manifold and an exhaust manifold, and being set up to allow the passage of air from the intake manifold to the exhaust manifold; the method comprising determining, in a design stage, a control law that provides an objective opening of a control actuator of the wastegate as a function of an actual supercharging pressure and of a reduced mass flow rate of the compressor; and correcting the reduced mass flow rate of the compressor as a function of the enthalpy of a gas mixture flowing through the turbine of the turbocharger.

主权项

1. A method for correcting the reduced mass flow rate of a compressor (14) in an internal combustion engine (1) turbocharged by means of a turbocharger (12) provided with a turbine (13) and with a compressor (14); the internal combustion engine (1) also comprising an intake manifold (4), an exhaust manifold (5) and a number of cylinders (2), each of which is connected to the intake manifold (4) by at least one respective inlet valve and to the exhaust manifold (5) by at least one respective exhaust valve; and in which the direct passage of air from the intake manifold (4) to the exhaust manifold (5) is allowed; the method comprises the steps of:
determining a control law (CL) that provides an objective opening of a wastegate (16) as a function of an actual supercharging pressure (P) and of a reduced mass flow rate (MR) of the compressor (14); correcting the reduced mass flow rate (MR) of the compressor (14) as a function of the enthalpy of a gas mixture flowing through the turbine (13) of the turbocharger (12) and comprising both exhaust gases leaving the cylinders (2) and the fresh air passing directly from the intake manifold (4) to the exhaust manifold (5); determining an objective supercharging pressure (Pobj); measuring an actual supercharging pressure (P); determining a first open-loop contribution (WGOL) of an objective position (WGobj) of the wastegate (16) by means of the control law (CL) and as a function of the objective supercharging pressure (Pobj); determining a second closed-loop contribution (WGCL1) of the objective position (WGobj) of the wastegate (16) by means of the control law (CL) and as a function of an actual supercharging pressure (P); and calculating the objective position (WGobj) of the wastegate (16) by adding the first open-loop contribution (WGOL) and the second closed-loop contribution (WGCL1); and controlling the wastegate (16) so as to pursue the objective position (WGobj) of the wastegate (16).