Method and device for regulating secondary air mass flow in secondary air supply of internal combustion engine

Abstract

The invention relates to a method for regulating a secondary air mass flow in a secondary air supply of an internal combustion engine, the internal combustion engine having a secondary air supply, a device for determining a pressure (pS) in the secondary air supply, and an exhaust gas lambda sensor for determining a current exhaust gas lambda value (lambda sens), the method comprises the following steps: a) determining a first secondary air mass flow () dependent on an effective throttle area (Aeff) by means of a throttle equation and as a function of a pressure (pS) in the secondary air supply, b) determining a second secondary air mass flow () starting from the measured exhaust gas lambda value (lambda sens) and taking into account the primary air mass flow () of the internal combustion engine and the supplied fuel mass flow (), c) deriving an effective throttle area (Aeff) from the first secondary air mass flow () determined in step a) and the second secondary air mass flow () determined in step b), d) adjusting the secondary air mass flow in the secondary air supply using the effective throttle area (Aeff) determined in step c) or the variable derived therefrom.

Description

TECHNICAL FIELD

[0001] The present application relates to a method for regulating a mass flow of secondary air in a secondary air supply device of an internal combustion engine. Furthermore, the present application relates to a regulating device for regulating a mass flow of secondary air in a secondary air supply device of an internal combustion engine. BACKGROUND

[0002] In recent years, the emissions of modern internal combustion engines have been significantly reduced by a large number of measures. The continuous strengthening of existing exhaust gas limits and the regulation of additional harmful substance components, such as for example NH3, in different markets leads to an increase in the complexity of exhaust gas aftertreatment systems.

[0003] A measure for increasing the temperature in exhaust gas aftertreatment systems is secondary air injection. Here, an external air mass flow is introduced into the exhaust manifold at the outlet valve of the motor, which air mass flow, in combination with a rich combustion chamber lambda, exothermically reacts at the hot surfaces of the manifold and the turbocharger.

[0004] For the target value determination of the secondary air injection, target values for the combustion chamber lambda (untreated emissions of the internal combustion engine) and the exhaust gas lambda (catalytic conversion capability) can for example be predefined. From the ratio of these two lambda target values and the current exhaust gas mass flow, the required secondary air quantity can for example be determined.

[0005] Deviation of the actual secondary air mass flow here leads to a deviation of the actual exhaust gas lambda and can limit the catalytic conversion capability of the catalyst. In order to regulate the exhaust gas lambda, the combustion chamber lambda target value can be adapted on the basis of the actual secondary air mass flow, however, the possibly increased untreated emissions of the internal combustion engine must thereby be tolerated.

[0006] It is therefore desirable to regulate the secondary air mass flow by means of the air path (within the adjustment limits).

[0007] It is therefore the object of the present application to provide a method and a regulating device for regulating a mass flow of secondary air in a secondary air supply device, which enable an improved regulation of the mass flow of secondary air in an internal combustion engine. SUMMARY

[0008] The present application relates to a method for regulating a mass flow of secondary air in a secondary air supply device of an internal combustion engine, wherein the internal combustion engine has a secondary air supply device, a device for determining a pressure (p S ) in the secondary air supply device and an exhaust gas lambda probe for determining a current exhaust gas lambda value (l sens ), wherein the method comprises the following steps: a) determining a required secondary air mass flow (m S) to determine a first secondary air mass flow ( eff ) related to the effective throttle area (A ), b) determining a second secondary air mass flow (m ) from the measured exhaust gas lambda value (λ sens ) and taking into account the primary air mass flow (m ) of the internal combustion engine and the supplied fuel mass flow (m ), c) deriving the effective throttle area (A eff ) from the first secondary air mass flow (m ) determined in step a) and the second secondary air mass flow (m ) determined in step b), d) adjusting the secondary air mass flow in the secondary air supply device (3) using the effective throttle area (A eff ) determined in step c) or a quantity derived therefrom.

[0009] In the method for adjusting the secondary air supply device, the secondary air mass flow is determined in two different ways. On the one hand, a first secondary air mass flow related to the effective throttle area is determined on the basis of the pressure ratio in the exhaust system by means of a throttle equation. On the other hand, a second secondary air mass flow is determined on the basis of the measured exhaust gas lambda value. From these two secondary air mass flows, which are acquired in different ways, the effective throttle area is derived. The effective throttle area thus determined is used to adjust the secondary air mass flow in the secondary air supply device of the internal combustion engine. In particular, the effective throttle area can be used, for example, to determine the actual secondary air mass flow precisely. Precise adjustment of the secondary air mass flow in the secondary air supply device is achieved by using the effective throttle area determined as described above.

[0010] Furthermore, the invention relates to an adjustment device for adjusting the secondary air mass flow in a secondary air supply device of an internal combustion engine, wherein the internal combustion engine has a secondary air supply device for supplying secondary air, a device for determining the pressure (p S ) in the secondary air supply device, an exhaust gas lambda probe for determining the current exhaust gas lambda value (λ sens ), wherein the adjustment device is designed to a) determine a first secondary air mass flow (m ) related to the effective throttle area (A eff ) by means of a throttle equation and from the pressure (p S ) in the secondary air supply device, b) determine a second secondary air mass flow (m ) from the measured exhaust gas lambda value (λ sensStarting from and taking into account the primary air mass flow of the internal combustion engine ( ) and the supplied fuel mass flow ( Determine the second-stage air mass flow under the condition of ) ), c) The first-stage air mass flow determined in step a) The second-stage air mass flow determined in step b) and step d) The effective throttling area (A) is derived from this. eff ), d) Using the effective throttling area (A) determined in step c) eff The secondary air mass flow in the secondary air supply device is adjusted in the case of parameters derived therefrom.

[0011] Advantageously, in step a), the first-stage air mass flow is determined using the throttling equation. This throttling equation will reduce the first-stage air mass flow ( ) and the pressure in the secondary air supply unit (p S ) and effective throttling area (A eff (related to)

[0012] Preferably, in step c), the effective throttling area is derived from the exhaust gas λ value using mass flow balancing.

[0013] Further preferred is to derive the effective throttling area in step c) taking into account the time dynamics of the exhaust gas λ detector.

[0014] According to a preferred embodiment, in step c), the effective throttling area (A) is derived using either the recursive minimum mean method (LMS) or the recursive normalized minimum mean method (NLMS). eff Using this type of recursive method, it is possible to accurately determine the effective throttling area.

[0015] Preferred to be pressure (p) S The secondary air mass flow derived from the exhaust gas λ value and the secondary air mass flow derived from the exhaust gas λ value. The difference is used as the error term for the recursive minimum mean method (LMS) or the recursive normalized minimum mean method (NLMS).

[0016] The preferred method is to adjust the secondary air mass flow based on the actual value of the secondary air mass flow, using the effective throttling area (A). eff The actual value is determined under the following circumstances.

[0017] Advantageously, the secondary air mass flow is adjusted based on the actual value of the secondary air mass flow, which is related to the effective throttling area (A). effThe first-stage air mass flow and the effective throttling area (A) determined in step c) are related. eff It is derived from ).

[0018] The secondary air mass flow is preferably adjusted based on the actual value of the secondary air mass flow and a pre-defined target value of the secondary air mass flow as a function of time.

[0019] According to a preferred embodiment, the target value of the secondary air mass flow is predetermined in the form of a time-dependent target secondary air mass flow, or in the form of a time-dependent target exhaust gas λ value, or in the form of a time-dependent target pressure in the secondary air supply device.

[0020] The adjustment parameters for the adjustment mechanism are preferably derived from the actual and target values ​​of the secondary air mass flow, wherein an adjustable secondary air pump or an adjustable electric auxiliary compressor is used as the adjustment mechanism in particular.

[0021] According to a preferred embodiment, the regulating device is designed to regulate the secondary air mass flow by means of an adjustable secondary air pump or by means of an adjustable electric auxiliary compressor. Attached Figure Description

[0022] The implementation method will now be explained in more detail with reference to the accompanying drawings. Wherein: Figure 1 An overview diagram of the exhaust system is shown. Figure 2 A physical model of the secondary air supply unit is shown. Figure 3 The method for obtaining the effective throttling area A is shown. eff A schematic diagram of the estimation algorithm. Detailed Implementation

[0023] The measure used to increase the temperature in the exhaust aftertreatment system is secondary air injection. Here, an external mass flow of air is introduced into the exhaust manifold at the motor's outlet valve. This mass flow of air, combined with the rich combustion chamber λ, undergoes an exothermic reaction at the hot surfaces of the manifold and turbocharger.

[0024] The method and regulating device for regulating the secondary air mass flow in the secondary air supply system of an internal combustion engine, as described below, are based on a physical model of the secondary air supply system. The following is based on... Figure 1 To illustrate this model. Figure 1 The diagram shows an internal combustion engine 1 along with an exhaust system 2 and a secondary air supply device 3. In the combustion chamber of the internal combustion engine 1, the supplied fuel mass flow... With the supplied primary air mass flow Partial conversion. The secondary air mass flow is converted through the secondary air supply unit 3. The exhaust gas mass flow supplied to exhaust system 2 involves an exothermic reaction between unburned fuel and the supplied secondary air. An exhaust gas λ sensor 4 is installed in exhaust system 2, designed to determine the exhaust gas λ value. sens .

[0025] The secondary air supply unit 3 can be considered as a throttle valve. A pressure sensor 5 is arranged in the secondary air supply unit 3, which is designed to determine the pressure p in the secondary air supply unit 3. S Secondary air mass flow Based on the pressure p3 modeled in exhaust system 2 and the pressure p measured in secondary air supply device 3 S The pressure difference between them is used to set the effective throttling area A. eff To describe, the effective throttling area is in Figure 1 It is also drawn together in the middle.

[0026] The physical model mentioned above describes the pressure p in the secondary air supply unit 3. S and the measured exhaust gas λ value λ sens The relationship between the physical model. Figure 2 The diagram is schematically shown. Since the secondary air supply device 3 can function as a throttle valve, it is possible to adjust the pressure p in the secondary air supply device 3 in step 6. S The temperature T in the secondary air supply unit 3 S The pressure p3 and effective throttling area A in exhaust system 2 eff The secondary air mass flow is determined using the throttling equation. Based on this determined secondary air mass flow Primary air mass flow and fuel mass flow Then, the λ calculation can be performed to obtain the λ value in terms of computation. sum Then, by using λ kinetics 8, that is, by taking into account the kinetics and dead time of the exhaust gas λ sensor 4 (which are determined by the parameter τ) sens and σ sens (to represent), the λ value of this calculation aspect λ sum This is converted into the actual exhaust gas λ value measured by exhaust gas λ sensor 4. sens (t).

[0027] As an alternative, the mass flow determined by the throttling equation can be... Delayed to the position of the λ detector (PT1 + dead time). By delaying the... The area is adapted by comparing the mass flow (from the throttle valve) with the λ-based mass flow (via the λ sensor). To determine the λ-based mass flow, the difference between the measured exhaust gas λ (at the detector) and the target combustion chamber λ (in the combustion chamber) is considered (it is also advantageous here to synchronize the two λ, that is, to delay the combustion chamber λ with respect to the position of the detector (PT1 + dead time)).

[0028] The following shows the use of Figure 2 The calculations are based on the physical model shown. The secondary air mass flow passes through the secondary air supply device 3, which can be described as a throttle valve. It can be achieved by using the throttling equation: (1) To indicate, among which, This indicates the pressure p3 in exhaust system 2 and the pressure p in secondary air supply unit 3. S The pressure ratio between them. Here, A eff It is the effective throttling area, p S It is the pressure in the secondary air supply unit 3, and T S It refers to the temperature of the secondary air. Ψ (Π) S ) indicates dependence on pressure ratio Π S Flow function: (2) Among them, Π crit =0.528, and Ψ crit = 0.484.

[0029] exist Figure 2 In the subsequent λ calculation 7 of the model shown, the total supply of air ( + Starting from this point, we will calculate λ in terms of computation, i.e., λ. sum The calculation is as follows: (3) Where, λ sto =14.7 represents the stoichiometric ratio when converting fuel to air. If using a combustion chamber λ (4) If we transform the equation in this case, we get: (5) according to Please provide a solution: (6).

[0030] In the subsequent λ dynamics 8, considering the dynamics and dead time of the exhaust gas λ sensor 4, the dynamic characteristics of the λ segment can be modeled, for example. For this purpose, the following differential equation can be used, for example: (6) Where, λ sum λ and τ represent the values ​​obtained from computation. sens and σ sens Let represent the parameters used to model the λ dynamics, and λ sens (t) represents the exhaust gas λ value detected by exhaust gas λ sensor 4.

[0031] Based on about Figure 2 The model equations of the physical model shown are now constructed for the effective throttling area A. eff An estimation algorithm is used to obtain the effective throttling area A. eff The handling method is in Figure 3 The diagram illustrates this point. The purpose is to obtain the effective throttling area A. eff Then, the effective throttling area A obtained in this way can be... eff Used to regulate secondary air mass flow.

[0032] First, it should be described Figure 3 The area A shown is used to evaluate the effective throttling area. eff The lower path of the scheme. In the lower path, the exhaust gas λ value λ is measured by exhaust gas λ sensor 4. sens Starting from (t), by means of reverse λ calculation 9 and using primary air mass flow and fuel mass flow Calculate the assigned secondary air mass flow under the following conditions In order to determine Instead, we use the formula derived from the definition of λ: (7) and (8), Where, λ sto This indicates the stoichiometric ratio of air to fuel. λ represents the mass flow of fuel supplied. sens This represents the measured value of exhaust gas, λ. Motor Let λ represent the combustion chamber, and This indicates the primary air mass flow.

[0033] exist Figure 3 In the upper path of the scheme shown, the throttling equation is used in the first step 10: (9) Determine the effective throttling area A eff Related secondary air mass flow (In the absence of an effective flow-throttling area). Here, Π S Indicates pressure ratio p S T represents the pressure in the secondary air supply unit 3. S p3 represents the temperature in the secondary air supply unit 3, and p3 represents the pressure in the exhaust system 2. Ψ (Π) is defined in formula (2).

[0034] With the help of subsequent λ kinetics 11, the passage parameter τ of the exhaust gas λ sensor 4 is... sens and σ sens The described dynamics and dead time are applied to the secondary air mass flow thus obtained in relation to the effective throttling area. Above. In this way, time-dependent secondary air mass flow related to the effective throttling area is obtained. The secondary air mass flow is compared with the measured exhaust gas λ value. sens The secondary air mass flow determined by (t) Synchronization. This is to apply λ-dynamics to the time-dependent secondary air mass flow related to the effective throttling area. The above uses the following differential equation: (10).

[0035] Next, from the secondary air mass flow determined in the path below and the secondary air mass flow related to the effective throttling area as determined in the path above. Determine the effective throttling area A eff This step is in Figure 3 The drawing in the middle is step 12.

[0036] To determine the effective throttling area A eff And able to convert parameters Divide by parameter However, it has been shown that such quotient formation can lead to inaccurate results. In particular, when the secondary air mass flow becomes very small or even close to zero, it may result in inaccurate results for the effective throttling area A. eff The inaccurate value.

[0037] For this reason, it is advantageous to use a recursive least squares algorithm to recursively determine the effective throttling area A. effIn the current case, for example, the LMS (Least Mean Square) algorithm can be used, or more preferably, the NLMS (Normalized Least Mean Square) algorithm. The starting point for recursively determining the effective throttling area is formed by the following equation: (11) This equation establishes the secondary air mass flow per unit effective throttling area, determined by the throttling equation. The secondary air mass flow determined by means of exhaust gas λ sensor 4 The relationship between them.

[0038] For cases where the LMS (Least Mean Square) algorithm is used as a self-adaptive algorithm, it is obtained as an adaptation factor in the derivation. and scalar cases Where w represents the regression number, K represents the proportionality constant, and error represents the error. In the current case, the regression number w is obtained from the throttling equation for the secondary air mass flow in the absence of an effective throttling area. However, if the secondary air mass flow is close to zero, the fit factor may become infinite in the LMS algorithm, for example.

[0039] To avoid this problem, it is advantageous to use the NLMS (Normalized Least Mean Square) algorithm in the implementation. The fit factor for the NLMS algorithm is... In the scalar case, we obtain Using the improved NLMS algorithm, the recursive evaluation of the effective throttling area yields: (12) Here, K id These are the parameters set for estimating the velocity. The difference equation is repeated for each time step.

[0040] Therefore, the effective throttling area A can be determined from the λ information provided by the λ sensor. eff Furthermore, no additional data input is required. The throttling equation can then be used for the forward path (…). → And used for reverse paths ( → ), so that the two paths can be calculated consistently. In particular, for example, the NLMS algorithm described above can be used to convert the λ information with respect to the running time into the effective area and couple the input into the pressure modeling. Then, for example, it can be regulated by a conventional PID controller, where, ( () is used as an adjustment parameter.

[0041] This invention can also be extended to other exhaust topologies. When multiple valves are present in the secondary air supply unit, it is feasible, for example, to replace p S Other baseline parameters, such as exhaust back pressure or boost pressure, can be used to model the throttle valve. These modeled parameters can also be used instead of pressure sensors.

[0042] The following describes how such a determined effective throttling area A can be... eff This is used to regulate the secondary air mass flow. Therefore, the actual value of the secondary air mass flow must first be determined.

[0043] Determining an actual value of the secondary air mass flow .

[0044] In particular, the effective throttling area A is achieved by using LMS or NLMS algorithms. eff The determination described above enables precise determination of the actual value of the secondary air mass flow in the secondary air supply unit. The starting point for this is again the throttling equation. From the effective throttling area A... eff Starting from the estimated value obtained, the actual value of the secondary air mass flow is obtained according to equation (1): in, This indicates the pressure p3 in exhaust system 2 and the pressure p in secondary air supply unit 3. S The pressure ratio between them. Here, p3 is the pressure in exhaust system 2, p S It is the pressure in the secondary air supply unit 3, and T S It is the temperature of the secondary air. (In used to determine A) effEst,k In the time-discrete representation (in which index k is continuously numbered for discrete time steps), the secondary air mass flow The result is: (13) in, It is the secondary air mass flow related to the effective throttling area, which has λ dynamics described by equation (6), and A effEst,k It is an estimate of the effective throttling area with respect to the time step k.

[0045] Providing a time-dependent target value of the secondary air mass flow.

[0046] In order to regulate the secondary air mass flow in the secondary air supply system as a function of time, a target value for the secondary air mass flow is needed, especially during the start-up phase of the internal combustion engine, where the temporal trend of the secondary air mass flow is predetermined. Three feasible solutions exist for providing this target value.

[0047] According to the first feasible option, the target value is... A function that can be directly given a time value in advance.

[0048] According to the second feasible solution, the target value of exhaust gas λ is... and the target value of combustion chamber λ A function pre-defined as time. Using the equation: (14) in, Able to target the value of exhaust gas λ and the target value of combustion chamber λ Converted to secondary air mass flow target value Here, λ sto =14.7 represents the stoichiometric ratio when converting fuel to air. This indicates the primary air mass flow, and This indicates the fuel mass flow.

[0049] The third feasible option is to adjust the target pressure in the secondary air supply unit 3. It is a function pre-defined as time. Then it is possible to obtain the target pressure. The target value of the secondary air mass flow is derived by using the throttling equation. : (15) Using the reverse throttling equation: (16) in, This indicates the pressure p3 in exhaust system 2 and the pressure in secondary air supply unit 3. The pressure ratio between them. Here, p3 is the pressure in exhaust system 2. It is the target pressure in the secondary air supply unit 3, and T S It is the temperature of the secondary air.

[0050] Determining an adjustment deviation and an adjustment variable for the adjustment mechanism .

[0051] Target value from secondary air mass flow Actual value of secondary air mass flow The adjustment bias is obtained from the difference between (t): Adjustment deviation = .

[0052] Then, the adjustment parameters for the adjustment mechanism can be determined from the adjustment deviation to regulate the secondary air mass flow. Different feasible solutions exist depending on the configuration for regulating the secondary air mass flow.

[0053] According to the first feasible solution, the secondary air mass flow can be regulated by means of an regulated secondary air pump, wherein air is drawn from the air filter.

[0054] According to a second feasible scheme for regulating the secondary air mass flow, an electric auxiliary compressor can be installed in the secondary air section, particularly in a motor with a turbocharger, wherein air is preferably taken out after the turbocharger.

[0055] According to a third feasible approach for regulating the secondary air mass flow, air can be drawn from the turbocharger in a motor equipped with a turbocharger, and the existing boosting system can be used to set the target pressure required for the secondary air target mass flow. It is also advantageous to include an electric auxiliary compressor if necessary.

[0056] Alternatively, an adjustable valve, for example in the form of an adjustable throttle, can be installed in the secondary air supply unit to regulate the secondary air mass flow.

[0057] The features disclosed in the foregoing description, claims and drawings are important not only individually but also in any combination for the implementation of the invention in its various design aspects.

Claims

1. A method for regulating a mass flow of secondary air in a secondary air supply device (3) of an internal combustion engine (1), wherein The internal combustion engine (1) has a secondary air supply device (3), a device for determining a pressure (p S ) in the secondary air supply device (3) and an exhaust gas lambda probe (4) for determining a current exhaust gas lambda value (l sens ), wherein the method comprises the following steps: a) determining a first secondary air mass flow (m ) related to an effective throttle area (A eff ) by means of a throttle equation and depending on a pressure (p S ) in the secondary air supply (3), S b) determining a second secondary air mass flow (m ) related to the effective throttle area (A eff ) by means of a throttle equation and depending on a pressure (p S ) in the secondary air supply (3), S c) determining a third secondary b) determining a second secondary air mass flow (Qsec,2) from the measured exhaust gas lambda value (l sens ) and taking into account the primary air mass flow (Qpri) of the internal combustion engine (1) and the supplied fuel mass flow (Qfuel) ) ) ) c) The first-stage air mass flow determined in step a) The second-stage air mass flow determined in step b) and step d) The effective throttling area (A) is derived from this. eff ), d) Using the effective throttling area (A) determined in step c) eff The secondary air mass flow in the secondary air supply device (3) is adjusted in the case of parameters derived therefrom.

2. The method of claim 1, wherein, determining the first secondary air mass flow (m ) in step a) by means of the throttle equation, which correlates the first secondary air mass flow (m ) with the pressure (p S ) in the secondary air supply and the effective throttle area (A eff ).

3. The method of claim 1 or claim 2, wherein, In step c) the effective throttle area is derived from the exhaust gas lambda value by means of a mass flow balance.

4. The method according to any of the preceding claims, characterized in that, In step c) the effective throttle area is derived taking into account the time dynamics of the exhaust gas lambda probe (4).

5. The method according to any of the preceding claims, characterized in that, The effective throttle area (Aeff) is derived in step c) using a Least Mean Square method (LMS) or a Normalized Least Mean Square method (NLMS) eff .

6. The method of claim 5, wherein, The difference between the secondary air mass flow derived from the pressure (p S ) and the secondary air mass flow derived from the exhaust gas lambda value (λ ) is used as an error term for the recursive least mean method (LMS) or the recursive normalized least mean method (NLMS).

7. The method according to any of the preceding claims, characterized in that, The secondary air mass flow is adjusted in accordance with an actual value of the secondary air mass flow, which is determined with the use of the effective throttle area (A eff ).

8. The method according to any of the preceding claims, characterized in that, adjusting the secondary air mass flow in accordance with an actual value of the secondary air mass flow, which is derived from the first secondary air mass flow associated with the effective throttle area (A eff ) and the effective throttle area (A eff ) determined in step c).

9. The method according to any of the preceding claims, characterized in that, The secondary air mass flow is regulated in accordance with the actual value of the secondary air mass flow and a target value of the secondary air mass flow which is predefined as a function of time.

10. The method of claim 9, wherein, The target value of the secondary air mass flow is predefined in the form of a target secondary air mass flow which is dependent on time or in the form of a target exhaust gas lambda value which is dependent on time or in the form of a target pressure in the secondary air supply (3) which is dependent on time.

11. The method of claim 9 or claim 10, wherein, An adjustment variable for an adjustment mechanism is derived from the actual value and the target value of the secondary air mass flow, wherein in particular an adjustable secondary air pump or an adjustable electric additional compressor is used as adjustment mechanism.

12. A regulating device for regulating the mass flow of secondary air in a secondary air supply device (3) of an internal combustion engine (1), wherein The internal combustion engine (1) has: a secondary air supply (3) for supplying secondary air; - means for determining the pressure (p S ) in the secondary air supply device (3). an exhaust gas lambda probe (4) for determining a current exhaust gas lambda value (l sens ), wherein the regulating device is designed to a) determining a first secondary air mass flow (m ) related to the effective throttle area (A eff ) by means of a throttle equation and depending on a pressure (p S ) in the secondary air supply (3), S eff S eff S eff S eff S eff S < b) From the measured exhaust gas λ value (λ sens ) starts and takes into account the primary air mass flow of the internal combustion engine (1) ) and the supplied fuel mass flow ( Determine the second-stage air mass flow under the condition of ) ), c) The first-stage air mass flow determined in step a) The second-stage air mass flow determined in step b) and step d) The effective throttling area (A) is derived from this. eff ), d) Using the effective throttling area (A) determined in step c) eff The secondary air mass flow in the secondary air supply device (3) is adjusted in the case of parameters derived therefrom.

13. The conditioning apparatus of claim 12, wherein, The regulating device is designed to regulate the secondary air mass flow by means of an adjustable secondary air pump or by means of an adjustable electric additional compressor or an adjustable secondary air valve.

14. An exhaust system of an internal combustion engine (1) having a regulating device according to claim 12 or claim 13.

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