Method of running an internal combustion engine

Abstract

The invention relates to a method for operating an internal combustion engine (100) having an exhaust gas turbocharger (5, 10, 15) for compressing air fed into the internal combustion engine (100), wherein the exhaust gas The drive power of the turbine (10) of the turbocharger (5, 10, 15) in the exhaust line (20) of the internal combustion engine (100) is changed by changing the turbine geometry of the turbine (10), wherein , in the first regulation algorithm (I), according to the setpoint exhaust gas backpressure (pT 1Soll ) controls the nominal boost pressure (pL Soll ), wherein, the rated boost pressure (pL Soll ) is adapted to the opening cross-section of the turbine (10) through the adjustment path of the adjusting element (25) assigned to the turbine (10) according to the assigned nominal boost pressure (pL Soll ) rated value (25 Soll ) is manipulated. According to the invention it is provided that the rated exhaust gas backpressure (pT 1Soll ) In the case of the upper limit value, the adjusted rated value (25' Soll ) controls the control element (25) of the turbine (10) controlled by the first control algorithm (I), said condition comprising: the presence of the turbine (10) in the primary control path a) of the second control algorithm (II) Upstream regulation deviation (ΔpT), which is determined by the actual exhaust backpressure upstream of the turbine (10) (pT 1Ist ) and the rated exhaust back pressure upstream of the turbine (10) (pT 1Soll ) and a regulation deviation (ΔpL) downstream of the compressor (5) occurs in the secondary regulation path b) of the second regulation algorithm (II), which is determined by the actual increase in the compressor (5) Pressure (pL Ist ) and the rated boost pressure at the output of the compressor (5) (pL Soll )inferred.

Description

technical field [0001] The invention relates to a method for operating an internal combustion engine with an exhaust gas turbocharger for compressing air fed into the internal combustion engine, wherein the exhaust gas turbocharger drives a turbine in the exhaust gas line of the internal combustion engine Power is varied by changing the turbine geometry of the turbine. Background technique [0002] Patent document EP 1 471 234 A2 describes an exhaust gas turbocharger (ATL) which is provided for compressing the air fed into an internal combustion engine. In this case, the drive power of the turbine of the exhaust gas turbocharger in the exhaust line of the internal combustion engine (VKM) is changed by changing the geometry of the turbine. It is also referred to here as an exhaust gas turbocharger (ATL) with a turbine with variable turbine geometry (VTG), abbreviated as VTG-ATL. In this case, the exhaust gas flowing through the turbine encounters guide vanes which are adjus...

AI Technical Summary

Problems solved by technology

[0003] A disadvantage of the known method is that the adjustment of the adjusting element for adjusting the turbine geometry is only determined on the basis of the detected pressure in the exhaust line after the turbine in the direction of exhaust gas flow and in the exhaust line in front of the turbine in the direction of exhaust gas flow. The calculated value of the pressure determined

As already mentioned, high exhaust gas backpressures can arise during operation of an internal combustion engine with VTG-ATL, which lead to high residual gas contents in the combustion chamber and, on the other hand, to the dynamic state of supercharging Poor pressure regulation

In particular, such dynamic states, which lead to poor regulation of the charge pressure, are not taken into account in conventional methods

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