DE102015216099A1 - Method and device for operating an internal combustion engine with exhaust gas recirculation - Google Patents

Abstract

The invention relates to a method for operating an internal combustion engine (2) in an exhaust gas recirculation engine system (1), comprising the following steps:
- operating the internal combustion engine (2) by adjusting an amount of recirculated combustion exhaust gas;
- Setting the amount of recirculated combustion exhaust gas depending on a pilot control and a control; and
Upon an increase in a load request, modifying the pilot control so that during the transition to the load indicated by the load request, the amount of recirculated combustion exhaust gas is reduced to an amount of recirculated combustion exhaust gas that is less than the amount of recirculated combustion exhaust gas remaining in the exhaust gas stationary operating case at a load corresponding to the increased load requirement results.

Description

Technical area

The invention relates to internal combustion engines, in particular fuel-driven internal combustion engines with exhaust gas recirculation. Furthermore, the invention relates to measures for improving the response of such internal combustion engines in dynamic operation, especially in sudden load increases.

Technical background

The exhaust gas recirculation (EGR) basically serves to reduce the oxygen content in the cylinders of an internal combustion engine and thereby the temperature resulting from the combustion. This can reduce the formation of nitrogen oxides during the firing process in the internal combustion engine.

Rapid increases in load result in a combustion engine with an exhaust-driven charging device due to the moment of inertia of the charging device and due to a dead volume between a compressor of the charging device and the intake valve of the internal combustion engine to a delayed buildup of the boost pressure. Additional exhaust gas recirculation enhances this effect, since recirculated exhaust gas recirculated during active exhaust gas recirculation limits the amount of fresh air supplied into the combustion chambers of the cylinders.

To set the recirculated exhaust gas mass flow (EGR mass flow), a fresh air mass flow control or an EGR rate control or an EGR mass flow control are known from the prior art. In the EGR rate control approaches are known, according to which the EGR rate is adjusted based on a physical model of the gas supply system or adjusted according to a conventional PID controller based on a fresh air mass flow deviation or an EGR rate deviation.

From the publication DE10 2013 209 037 A1 a method for operating an exhaust gas recirculation of a self-igniting internal combustion engine is known, wherein the internal combustion engine has an air system for controlling the air supply in at least one combustion chamber of the internal combustion engine. A dynamic operating state of the internal combustion engine is detected and in the event of a detected dynamic operating state, a corrective intervention in the air system of the internal combustion engine is performed.

Disclosure of the invention

According to the invention, a method for operating an internal combustion engine with exhaust gas recirculation according to claim 1 and a device and an engine system according to the independent claims are provided.

Further embodiments are specified in the dependent claims.

• – Betreiben des Verbrennungsmotors durch Einstellen einer Menge an rückgeführtem Verbrennungsabgas;
• – Einstellen der Menge an rückgeführtem Verbrennungsabgas abhängig von einer Vorsteuerung und einer Regelung; und
• – bei einer Erhöhung einer Lastanforderung, Modifizieren der Vorsteuerung, so dass während des Übergangs zu der durch die Lastanforderung angegebenen Last die Menge an rückgeführtem Verbrennungsabgas auf eine Menge an rückgeführtem Verbrennungsabgas reduziert wird, die kleiner ist als die Menge an rückgeführtem Verbrennungsabgas, die sich im stationären Betriebsfall bei einer der erhöhten Lastanforderung entsprechenden Last ergibt.

According to a first aspect, a method is provided for operating an internal combustion engine in an exhaust gas recirculation engine system, comprising the following steps:

• - operating the internal combustion engine by adjusting an amount of recirculated combustion exhaust gas;
• - Setting the amount of recirculated combustion exhaust gas depending on a pilot control and a control; and
• Upon an increase in a load request, modifying the pilot control so that during the transition to the load indicated by the load request, the amount of recirculated combustion exhaust gas is reduced to an amount of recirculated combustion exhaust gas that is less than the amount of recirculated combustion exhaust gas remaining in the exhaust gas stationary operating case at a load corresponding to the increased load requirement results.

In an exhaust gas recirculation control e.g. Based on a PID controller, an EGR manipulated variable for adjusting the exhaust gas recirculation valve is generated based on a pilot control variable and an EGR control manipulated variable. The pilot control variable may be determined based on a physical model or map model of the gas routing system (e.g., a map of measured stationary EGR valve positions versus injection quantity and engine speed) depending on a load indication for a desired load, such as a desired load. from a desired injection quantity. The EGR control manipulated variable is correspondingly generated as a manipulated variable of a control, which can correspond to a PID control with applicable control parameters.

With a fast load increase, the pilot control variable is set correspondingly fast, so that the control only has to compensate for transient deviations. However, this results in the EGR mass flow being adjusted to correspond to the stationary EGR mass flow at the new operating point in the steady state case. During the transient transition, however, the adjusted EGR mass flow limits the amount of fresh air supplied to the combustion chambers of the cylinders, so that the increase in the output from the engine provided engine torque is slowed down accordingly and thereby delayed the buildup of a boost pressure by a charging device. As a result, the known as turbo lag effect of slow boost pressure build-up is enhanced.

In order to provide sufficient fresh air in the combustion chambers of the cylinders in the event of a sudden increase in load, the above method provides for modifying the EGR control variable during the transient transition so as to provide a lower EGR mass flow than the EGR mass flow which would be set by the conventional EGR pilot control and the conventional EGR control at the required steady state load. For this purpose, it is provided to modify the pilot control variable in such a way that the exhaust gas recirculation valve is closed further during the duration of the transient load change than would be the case with the requested stationary state. As a result, the amount of recirculated exhaust gas is reduced so much that a larger proportion of fresh air enters the combustion chambers of the cylinder. Thus, the torque can be provided faster according to the load request.

Furthermore, the amount of recirculated combustion exhaust gas can be determined depending on a sum of a pre-control predetermined Vorsteuerstellgröße and a predetermined by the regulation EGR control variable, the pilot control variable is modified depending on a transient indicator so that the specified by the pilot control variable amount of recirculated combustion exhaust gas during transition to the load indicated by the load request, is reduced from a steady state pilot control variable, which results as a pilot control variable after the transition to the load indicated by the load request.

In particular, the pilot control may only reduce the pilot control variable depending on a transient indicator to the reduced amount of recirculated combustion exhaust gas if the transient indicator indicates a dynamic behavior in the air supply system that exceeds a predetermined dynamic behavior threshold.

According to another embodiment, the control may be based on one or more control parameters, wherein at least one of the control parameters is changed during the transition to the load indicated by the load request.

It can be provided that the change of the at least one control parameter is determined as a function of a predetermined factor and / or a transient indicator.

Furthermore, the control may comprise a PID control, wherein in particular a proportional control component is increased during the transition to the load specified by the load request and / or an integration control component is reduced during the transition to the load specified by the load request and / or a differential control component is left unchanged or decreased during the transition to the load indicated by the load request.

In particular, an I-control part of the PID control can be reset depending on the transition to the load indicated by the load request, in particular depending on the transient indicator, in particular if the transient indicator indicates a dynamic behavior in the air supply system that exceeds a predetermined threshold for the dynamic behavior ,

It can be provided that the transient indicator indicates to what extent the increase in the load requirement causes a dynamic change in the air supply system of the engine system.

• – den Verbrennungsmotor durch Einstellen einer Menge an rückgeführtem Verbrennungsabgas zu betreiben;
• – die Menge an rückgeführtem Verbrennungsabgas abhängig von einer Vorsteuerung und einer Regelung einzustellen; und
• – bei einer Erhöhung einer Lastanforderung, die Vorsteuerung zu modifizieren, so dass während des Übergangs zu der durch die Lastanforderung angegebenen Last die Menge an rückgeführtem Verbrennungsabgas auf eine Menge an rückgeführtem Verbrennungsabgas reduziert wird, die kleiner ist als die Menge an rückgeführtem Verbrennungsabgas, die sich im stationären Betriebsfall bei einer der erhöhten Lastanforderung entsprechenden Last ergibt.

In another aspect, an apparatus for operating an internal combustion engine in an exhaust gas recirculation engine system is provided, the apparatus being provided to:

• To operate the internal combustion engine by adjusting an amount of recirculated combustion exhaust gas;
• To adjust the amount of recirculated combustion exhaust gas depending on a pilot control and a control; and
• Upon an increase in a load request, modify the feedforward such that during the transition to the load indicated by the load request, the amount of recirculated combustion exhaust gas is reduced to an amount of recirculated combustion exhaust gas that is less than the amount of recirculated combustion exhaust gas that dissipates results in steady-state operation at a load corresponding to the increased load requirement.

In another aspect, an engine system including an internal combustion engine and the above apparatus is provided.

Brief description of the drawings

Embodiments are explained below with reference to the accompanying drawings. Show it:

1 a schematic representation of an engine system with an exhaust gas driven charging and exhaust gas recirculation;

2 a functional diagram illustrating the function for operating the internal combustion engine with a regulated exhaust gas recirculation; and

3 a diagram illustrating the timing of the boost pressure, the target boost pressure, the air mass flow, the EGR control variable, the pilot control variable and the I and P control components.

Description of embodiments

1 shows an engine system 1 with an internal combustion engine 2 , which is usually several cylinders 3 includes. The internal combustion engine 2 can work on a four-stroke principle and in particular be designed as a fuel-driven internal combustion engine, in particular as a diesel engine.

The cylinders 3 of the internal combustion engine 2 is via an air supply system 4 Fresh air supplied. In operation, fuel is injected into the combustion chambers of the cylinders in accordance with a load request 3 injected, after combustion combustion gases via an exhaust gas discharge tract 5 be ejected.

In the air supply system 4 and in the exhaust discharge tract 5 is at least one exhaust gas driven charging device 6 intended. The charging device 6 includes a turbine 61 that are in the exhaust discharge tract 5 is arranged to convert an exhaust enthalpy of the combustion exhaust gas into mechanical energy. Furthermore, a compressor 62 provided with the turbine 61 , For example, mechanically via a shaft 63 , coupled to rotational energy, using the turbine 61 is obtained in compaction performance for compressing fresh air sucked from the environment in a boost pressure section 41 convert.

The boost pressure section 41 can be a section of the air supply system 4 define that is located between an outlet of the compressor 62 and one in the air supply system 4 arranged throttle 8th located. Furthermore, there can be a charge air cooler 44 be provided. Between the throttle 8th and the intake valves of the cylinders 3 then there is a Saugrohrabschnitt 42 of the air supply system 4 , In an air supply system 4 without throttle 8th corresponds to the boost pressure section 41 the entire section of the air supply system 4 between the outlet of the compressor 62 and intake valves (not shown) of the cylinders 3 ,

In the boost pressure section 41 can be a pressure sensor 43 be provided, which provides an indication of an actual boost pressure p _LDist . Alternatively, in a Saugrohrabschnitt 42 a pressure sensor may be provided with the aid of which the actual boost pressure p _LDist can be modeled.

It is still at least one recharge plate 64 provided that can adjust the height of the provided turbine power variable. The charging plate 64 For example, it can be designed as a wastegate valve, as a VTG controller (VTG: Variable Turbine Geometry) or in any other way. The charging plate 64 can by means of a suitable manipulated variable S, for example, a duty cycle for a servomotor of the charging plate 64 indicates to be set based on a boost pressure control.

It is also an exhaust gas recirculation line 7 provided, in succession, an exhaust gas cooler 71 for cooling the flowing recirculated combustion exhaust gas and an EGR valve 72 are located. Using the EGR valve 72 can produce a lot of combustion exhaust gas in the air supply system 4 initiated. The proportion of recirculated combustion exhaust gas in the cylinders 3 of the internal combustion engine 2 supplied fresh air is referred to as exhaust gas recirculation rate (EGR rate). The EGR rate or the EGR mass flow or the fresh air mass flow is dependent on an operating state of the internal combustion engine using an EGR control system 2 by placing the EGR valve 62 set using the EGR control value S _EGR . The EGR control variable S _EGR is used for direct control of the EGR valve 72 to set the EGR mass flow, the EGR rate, and the fresh air mass flow, respectively.

While the in 1 shown Abgasrückführunsgleitung corresponds to a high-pressure exhaust gas recirculation, the method described below can also be used with a low-pressure exhaust gas recirculation. For this purpose, a low-pressure exhaust gas recirculation line connects an output side of the turbine 61 with an input side of the compressor 62 and may alternatively or additionally be provided for high-pressure exhaust gas recirculation.

It is a control unit 10 provided for operating the internal combustion engine 2 the EGR valve 72 , the charger 64 , the throttle 8th and further actuators, such as fuel injection valves for determining the amount of fuel to be injected, controls. Overall, the control unit controls 10 the actuators depending on an externally provided information about a target torque as well as information about the current operating state of the internal combustion engine 2 , For example, indicated by speed and load and / or other operating state variables on. The nominal torque can be from a Driver request result, which is specified via an operation of an accelerator pedal.

2 shows the in the control unit 10 executed function to generate the EGR control variable S _EGR . The EGR control variable S _AGR is generated from an EGR pilot control variable S _V and an EGR controlled variable S _R. In particular, the pilot control variable S _V and the control manipulated variable S _{R are} in a first summation element 11 to obtain the EGR manipulated variable S _AGR .

The Vorsteuerstellgröße S _V depends in the case of a map-based feedforward control substantially of the result of a pilot block 12 from which the current injection quantity m _Fuel and an engine speed n _{mot is} specified so that it can calculate a stationary pilot control _variable S _VStat according to the injection _quantity and the engine speed in accordance with a stored pilot control model. The determination of the stationary pilot control _variable S _VStat is thus based on an ideal air supply system on the assumption that even with a load change, ie a load increase, the EGR mass flow or the EGR rate or the fresh air mass flow is adjusted as it required Load case in the steady state corresponds.

If the stationary pilot control variable S _VStat and the EGR control variable S _R are used directly to generate the EGR control variable S _AGR , this also leads to an increase in the EGR rate in the event of a rapid increase in load, which limits the fresh air supply and a rapid one Counteracts torque increase.

It is therefore envisaged to reduce the EGR rate and to set the EGR mass flow lower during the duration of a transient transition, ie while a load increase is occurring, than the EGR mass flow at the steady state requested load condition. This is achieved by using a so-called transient indicator TI. The transient indicator TI is in a transient indicator block 13 generated. The transient indicator TI essentially evaluates the deviation between a relevant target pressure and actual pressure in the air supply system. For example, the transient indicator TI corresponds to a variable, for example, the difference between the target boost pressure p _LDsoll , which is indicated by the load request, in particular a driver's desired _torque , which can be specified by an accelerator pedal, and a current boost pressure p _LDist . The transient indicator TI can evaluate this difference by an indication in a value range between 0 and 1, for example. For example, there may be high dynamics in the air supply system when the transient indicator TI is 1, and there may be steady state operation when the transient indicator TI is 0. In particular, the transient _indicator TI depending on a difference between the target boost pressure p _LDsoll and the actual boost pressure p _LDist eg the difference between the target boost pressure p _LDsoll and the actual boost pressure p _LDist divided by the target boost pressure p _{LDsoll be} determined , For adaptation to the respective operating point, the transient indicator TI can furthermore be determined as a function of an engine speed n _mot .

In a first multiplier 14 Now, the stationary pilot control _variable S _VStat can be _multiplied by a reduction _amount RB dependent on the transient _indicator TI, which is the lower, the higher the dynamics in the air supply system of the engine system 1 is. As a result of the multiplication, the pilot control variable S _V results. The reduction amount RB may be, for example, a difference between 1 and the transient indicator TI, namely, 1-TI. This means that in the event of a sudden increase in load, where a transient indicator of 1 results, the reduction amount becomes 0, so that the multiplication in the first multiplication element 14 No pilot control variable S _V is provided more or the pilot control variable has the value 0. Thus, with a value of the transient indicator TI of 1, which indicates a very high dynamic, initially the EGR control variable S _{AGR is also} reduced to 0.

To provide the EGR control variable S _R , a control unit 15 be provided in the form of a PID controller. The control unit 15 may be configured to provide a control of the fresh air mass flow, the EGR mass flow or the EGR rate. The PID controller 15 has a P-term 16 , an I-link 17 and a D-link 18 which in a manner known per se correspond to a proportional regulator component, an integration regulator component and a differential regulator component in a manner known per se. In a difference element 19 is a deviation between a target fresh _air mass flow m _{air, soll} and an actual fresh _air mass flow m _{air, is} or between a desired EGR rate EGR _soll and an actual EGR rate EGR _is or between a target EGR mass flow m _{EGR, soll} and an actual EGR mass flow m _{EGR, is} determined and the resulting control deviation to the P element 16 , the I-member 17 and the D-member 18 fed. The desired fresh _air mass flow m _{air, should} , the target EGR rate EGR _soll and the target EGR mass flow m _AGR, are given by an operating point of the engine system and possibly. Depending on a load specification, such as a driver's request. The actual values may be provided as corresponding sensor values or by modeling.

The from the P-member 16 resulting P-component P can be in a P-transient block 20 be modified by means of an applicable P-factor FP depending on the transient indicator TI to a modified P-law component P '. Analogous to that from the I-member 17 resulting I component I in an I-transient block 21 be modified with the aid of an applicable I-factor FI depending on the transient indicator TI to a modified I-rule component I '. The from the D-member 18 resulting D component can be in a D-transient block 22 be modified by means of an applicable D-factor FD depending on the transient indicator TI to a modified D-control component D '.

The P-factor and / or the I-factor and / or the D-factor can be fixedly specified or by means of corresponding factor maps of a corresponding P-map block 23 , I-map block 24 or D-map block 25 depending on an operating point, which can be indicated, for example, by the engine speed n _mot and the injected fuel quantity m _fuel . The map blocks 23 . 24 . 25 are applicable and essentially determine the behavior of the PID controller 15 in transient operation. The modified P-law component P ', the modified I-component I' and the modified D-component D 'are stored in a second summer 26 added and the sum as EGR control variable S _R the first summation 11 made available.

In the transient blocks 20 . 21 . 22 For example, the modified P control component, the modified I control component and the modified D control component can be calculated as the sum of a product of the respective control component P, I, D with the transient indicator TI and with the P factor, I factor or D factor and the product can be calculated from the respective control component P, I, D with the reduction amount RB = 1-TI.

The ones in the transient blocks 20 . 21 . 22 Realized equations are used to continuously perform the transition from a stationary to a transient operation, so that no sudden changes in the EGR control variable S _R can occur.

Ultimately, the P factor map looks 23 in the case of a transient operation, to increase the modified P-law proportion P 'of the PID control with respect to the P-law P of the P-element, corresponding to that in the P-transient block 20 realized equation according to the P-factor FP.

Furthermore, the I-member 17 be reset to 0 or a predetermined value in a sudden load increase, which causes a transient indicator TI on a predetermined transient indicator threshold TI _TH . The corresponding comparison of the transient indicator TI with the predetermined transient indicator threshold TI _TH is in the comparison block 29 performed, a reset signal R to the I-member 17 provides.

The functioning of the in the 2 shown EGR control function is based on the temporal course of the 3 shown. 3 shows the time profiles of a desired boost pressure p _LDSoll , an actual boost pressure p _LDIst , a target fresh air _{mass flow} m _setpoint per cylinder, an actual fresh air _{mass flow} m _actual per cylinder, the EGR control variable S _AGR , the EGR pilot control variable S _V , the stationary pilot control _variable S _VStat , the modified P- _component P ', the modified I-component I' and the transient indicator TI. One recognizes by means of in 3 shown curves that when requesting a rapid increase in load at time T _0, the target boost pressure p _{LDSoll skyrockets} and the actual boost pressure p _LDist according to the requested increase in boost pressure by slowly increasing the exhaust _enthalpy corresponding to the requested target boost pressure P _LDSoll follows.

At the same time, this results in an increase of the air mass flow m _Ist flowing into the internal combustion engine corresponding to the desired air mass flow m _set , which corresponds to the maximum air mass flow that can be provided at the exhaust gas _enthalpy provided during the rise of the actual boost pressure p _LDIst . The erratic load request normally results in the pilot control variable S _V also suddenly assuming a new value which, in accordance with the underlying pilot control model, corresponds to the demand for recirculated combustion exhaust gas in the stationary operating case after the load increase. Instead, during the transient transition, the pilot control variable S _{V is} further reduced so as to reduce the amount of recirculated combustion exhaust gas and promote a larger amount of fresh air into the combustion chambers of the cylinders. The condition of the engine system is approaching 1 again the stationary state, the -Vordsteuerstellgröße S _{V is} returned to the now applicable value for the steady-state operating state. By _taking back the EGR pilot control _variable S _VAGR to the value 0 or close to the value 0, the increase in load of the internal combustion engine can be supported since the fresh air supply is temporarily increased.

The reduction of the pilot control variable S _V takes place in accordance with the course of the transient indicator TI, which has a value greater than 0 for the transient transition of the desired boost pressure p _LDSoll , and has a value 1, in particular in the case of large or sudden load increases, which in the course of approximation of the actual -Ladedrucks p _Ldist to the target boost pressure p _LDSoll again reached to 0.

The control parameters of the control unit 15 are adjusted accordingly during the transient state. The adjustment of the control parameters can also be carried out depending on the transient indicator TI, in particular depending on corresponding applicable factors, namely the P-factor, the I-factor and the D-factor, and. In particular, in order to realize the above behavior, the P-factor is increased and the I-factor is lowered. The D factor can then be left unchanged or also reduced in direction 0. The consideration of the modified factors takes place in accordance with the weighting which is predetermined by the transient indicator TI in each case. In order to support the reduction of the pilot control variable S _V and thereby the reduction of the amount of combustion exhaust gas returned to the cylinders, the I-control component of the I-member may be reset to 0 or a low value during a transient transition. This can be recognized by the sudden drop of the modified I component I 'at the moment of the load jump.

The above method adds to a conventional PID control for setting the EGR valve 72 before, in which the amount of recirculated combustion exhaust gas at transient load changes is significantly reduced, to increase the load by increasing the amount of fresh air supplied in the cylinders 3 of the internal combustion engine 2 to support.

QUOTES INCLUDE IN THE DESCRIPTION

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Cited patent literature

• DE 102013209037 A1 [0005]

Claims (13)

Method for operating an internal combustion engine ( 2 ) in an engine system ( 1 ) with exhaust gas recirculation, with the following steps: - operating the internal combustion engine ( 2 by adjusting an amount of recirculated combustion exhaust gas; - Setting the amount of recirculated combustion exhaust gas depending on a pilot control and a control; and, upon increasing a load request, modifying the pilot control so that, during the transition to the load indicated by the load request, the amount of recirculated combustion exhaust gas is reduced to an amount of recirculated combustion exhaust gas that is less than the amount of recirculated combustion exhaust gas that dissipates results in steady-state operation at a load corresponding to the increased load requirement. The method of claim 1, wherein the amount of recirculated combustion exhaust gas is determined depending on a sum of a pre-control Vorsteuerstellgröße (S _V ) and by the control (S _R ) predetermined EGR control variable, wherein the Vorsteuerstellgröße (S _V ) depending on that through the pilot control variable (S _V) amount of recirculated combustion exhaust gas during the transition to the direction indicated by the load demand load against a stationary pilot control value specified (S _vstat) is reduced to a Transientenindikator (TI) is modified so that (as a pilot control variable S _V ) after the transition to the load indicated by the load request. Method according to claim 2, wherein the precontrol reduces the pilot control variable (S _V ) depending on a transient indicator (TI) to the reduced amount of recirculated combustion exhaust gas only if the transient indicator (TI) has a dynamic behavior in an air supply system (TI). 4 ) of the engine system ( 1 ), which exceeds a predetermined dynamic behavior threshold. The method of claim 2 or 3, wherein the control is based on one or more control parameters (P, I, D), wherein at least one of the control parameters (P, I, D) is changed during the transition to the load indicated by the load request. Method according to Claim 4, wherein the change in the at least one control parameter (P, I, D) is determined as a function of a predetermined factor (FP, FI, FD) and / or a transient indicator (TI). The method of claim 4 or 5, wherein the control comprises a PID control, in particular a proportional control component is increased during the transition to the load specified by the load request and / or an integration control component during the transition to the specified by the load request Load is lowered and / or a differential control component is left unchanged or reduced during the transition to the load indicated by the load request. Method according to claim 6, wherein an I-control part of the PID control is reset depending on the transition to the load indicated by the load request, in particular depending on the transient indicator (TI), in particular if the transient indicator (TI) shows a dynamic behavior in the air supply system (TI). 4 ), which exceeds a predetermined dynamic behavior threshold. Method according to one of claims 2 to 7, wherein the transient indicator (TI) indicates the extent to which the increase in the load request a dynamic change in the air supply system ( 4 ) of the engine system ( 1 ) causes. The method of any one of claims 1 to 8, wherein the control includes EGR mass flow control, EGR rate control, or fresh air mass flow control Device for operating an internal combustion engine ( 2 ) in an engine system ( 1 ) with exhaust gas recirculation, wherein the device is designed to: - the internal combustion engine ( 2 ) by adjusting an amount of recirculated combustion exhaust gas; To adjust the amount of recirculated combustion exhaust gas depending on a pilot control and a control; and - increasing the load request to modify the feedforward such that, during the transition to the load indicated by the load request, the amount of recirculated combustion exhaust gas is reduced to an amount of recirculated combustion exhaust gas that is less than the amount of recirculated combustion exhaust gas results in steady-state operation at a load corresponding to the increased load requirement. Engine system ( 1 ) comprising: - an internal combustion engine ( 2 ); - An apparatus according to claim 10. Computer program adapted to carry out all the steps of a method according to one of Claims 1 to 9. A machine-readable storage medium on which a computer program according to claim 12 is stored.

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