Method for operating an internal combustion engine, control device for carrying out such a method and internal combustion engine with such a control device

Abstract

Method for operating an internal combustion engine (1) with at least two exhaust gas turbochargers (7), wherein - a first combustion chamber group (3.1) is assigned a first exhaust gas turbocharger (7.1), wherein - a second exhaust gas turbocharger (7.2) is assigned to a second combustion chamber group (3.2), wherein - a first compressor (9.1) of the first exhaust gas turbocharger (7.1) and a second compressor (9.2) of the second exhaust gas turbocharger (7.2) are fluidically connected downstream of the compressors (9), wherein - the first combustion chamber group (3.1) has a first combustion chamber (5.1) and a second combustion chamber (5.2), wherein - each combustion chamber (5) of the plurality of combustion chambers (5) is assigned at least one injector, wherein - the first combustion chamber (5.1), in particular a first injector, is monitored for injector failure, wherein - at least one first operating parameter of the first exhaust gas turbocharger (7.1) is monitored for compressor pumping, wherein - if an injector failure is detected in the first combustion chamber (5.1), in particular of the first injector, and in addition the first operating parameter exceeds a compressor pumping limit, a fuel injection rate of the second combustion chamber (5.2) is selected such that compressor pumping of the first exhaust gas turbocharger (7.1) is avoided.

Description

[0001] The invention relates to a method for operating an internal combustion engine with at least two exhaust gas turbochargers, a control device for carrying out such a method and an internal combustion engine with such a control device.

[0002] When operating an internal combustion engine with at least two exhaust gas turbochargers, compressor pumping can occur in at least one of the turbochargers, depending on the load point, engine type, and prevailing conditions. During this process, hot air flows back through the compressor of the at least one turbocharger in a pulsating manner, heating and potentially igniting filter material in an upstream air filter. One cause of compressor pumping is a lack of power in one of the turbocharger's turbines, resulting from a failure in the combustion chamber of the engine associated with that turbine.

[0003] Up to now, if a combustion chamber fails, the internal combustion engine continues to operate unchanged, and any resulting damage, in particular ignition of an air filter, and the associated failure of the internal combustion engine are accepted.

[0004] Japanese patent application JP H11-350 966 A discloses a method for stabilizing a turbocharged internal combustion engine. This method monitors a direct-injection fuel injector assigned to a cylinder of the engine and the engine's turbocharger. If a fault is detected in the fuel injector, the target boost pressure is reduced. Additionally, fuel injection is performed using a port fuel injector instead of the direct-injection fuel injector. This ensures homogeneous combustion. A disadvantage of this method is that the turbocharger's compressor is not monitored for compressor surging. Therefore, the method is not designed to prevent compressor surging in the turbocharger.

[0005] German publication DE 11 2008 001 300 T5 discloses a method for controlling an internal combustion engine with a turbocharger for powering a motor vehicle. The turbocharger has a compressor, and the engine also has a path for recirculating exhaust gas to the engine. Furthermore, the amount of recirculated exhaust gas is controllable by an EGR valve, which is controlled by a control unit. The method detects a negative fuel rate that exceeds a predetermined threshold. If this occurs, the internal combustion engine is operated in a mode in which the EGR valve is controlled to a more open position and the variable turbine geometry is controlled to a position in which it essentially generates a maximum turbine speed.

[0006] German patent application DE 102 37 416 A1 discloses a method for operating a compressor in the intake manifold of an internal combustion engine. A state variable describing the compressor's behavior is monitored. If the state variable exceeds or falls below at least a predetermined or predefinable limit value, a control and / or regulation action is taken, in particular by reducing the injection quantity. The state variable used is an output signal generated for the control and / or regulation of the internal combustion engine by an airflow sensor arranged in the intake manifold.

[0007] US patent application US 2019 / 0093586A1 discloses an engine control device that controls an engine with a turbocharger, a wastegate valve, an air bypass valve, and a high-pressure fuel system. The engine control device comprises an air bypass valve control unit and an anomaly detection unit. The air bypass valve control unit controls the air bypass valve. The anomaly detection unit detects an anomaly in the high-pressure fuel system. The air bypass valve control unit increases the opening degree of the air bypass valve in accordance with the anomaly detected by the anomaly detection unit.

[0008] US patent application US 2007 / 0095063A1 discloses a method for preventing a surge event in an engine system comprising a turbocharger and a diesel engine capable of operating at several discrete speeds. The method involves detecting an operating parameter of the engine system that defines a surge limit. It further determines whether a change in the detected operating parameter could lead to exceeding the surge limit. Additionally, an operating input to the engine system is controlled to prevent the surge event from occurring.

[0009] US patent application US 2020 / 0240424A1 discloses a vehicle with an engine system that can detect anticipated compressor pumping while the compressor is operating within a stable region of a compressor map. Upon detection of anticipated compressor pumping, at least one engine operating parameter is controlled to maintain compressor operation within the stable region of the compressor map without exceeding a compressor pumping curve. If the compressor pumping curve is exceeded, compressor pumping can occur.

[0010] The invention is therefore based on the objective of creating a method for operating an internal combustion engine with at least two exhaust gas turbochargers, a control device for carrying out such a method and an internal combustion engine with such a control device, wherein the aforementioned disadvantages are at least partially eliminated, preferably avoided.

[0011] The problem is solved by providing the present technical teaching, in particular the teaching of the independent claims as well as the embodiments disclosed in the dependent claims and the description.

[0012] The problem is solved, in particular, by providing a method for operating an internal combustion engine with at least two exhaust gas turbochargers. The internal combustion engine has a first combustion chamber group and a second combustion chamber group, wherein the first combustion chamber group is assigned a first exhaust gas turbocharger and the second combustion chamber group a second exhaust gas turbocharger. The first combustion chamber group comprises a first combustion chamber and a second combustion chamber. Each combustion chamber of the plurality of combustion chambers is assigned at least one injector for introducing fuel into the combustion chamber. In particular, each combustion chamber of the plurality of combustion chambers has at least one injector. Furthermore, a first compressor of the first exhaust gas turbocharger and a second compressor of the second exhaust gas turbocharger are fluidically connected downstream of the compressors.The first combustion chamber, in particular the first injector, is monitored for injector failure. Additionally, at least one operating parameter of the first exhaust gas turbocharger is monitored for compressor pumping. If an injector failure is detected in the first combustion chamber, in particular the first injector, and the operating parameter exceeds a predetermined compressor pumping limit, the fuel injection rate of the second combustion chamber, in particular a second injector, is selected such that compressor pumping of the first exhaust gas turbocharger is avoided.

[0013] Because the first and second compressors are fluidically connected downstream, pressure equalization of the air compressed by the first and second compressors occurs. If the first injector fails, the enthalpy flow and thus the exhaust pressure at the turbine of the first turbocharger drops significantly compared to the second turbocharger, assuming no injector failure in the second combustion chamber group. This results in a situation where the turbine output, and therefore also the compressor output, of the first turbocharger decreases, while the pressure downstream of the compressors remains almost constant. Depending on the boundary conditions, this can lead to compressor pumping in the first compressor.

[0014] In the context of this technical teaching, exceeding the predetermined compressor pumping limit of the first function parameter is direction-independent. Depending on the first function parameter, the first function parameter will therefore fall below or rise above the predetermined compressor pumping limit if the first function parameter exceeds the predetermined compressor pumping limit.

[0015] In the context of the present technical teaching, a fuel injection rate specifies a fuel mass per unit of time which is introduced by means of an injector into a combustion chamber, in particular into a combustion chamber of a combustion chamber, of an internal combustion engine.

[0016] Advantageously, by adjusting the fuel injection rate of the second first injector, it is possible to increase the enthalpy flow and exhaust pressure, thereby almost compensating for the failure of the first first injector. In this way, potential compressor pumping of the first compressor can be prevented. Advantageously, a change, particularly an increase, in the fuel injection rate of the second first injector is only necessary if the first operating parameter exceeds the predetermined compressor pumping limit.

[0017] In the context of the present technical teaching, a compressor pump limit is a parameter limit value, if exceeded there is at least a risk of compressor pumping or compressor pumping has already occurred.

[0018] The fuel injection rate of the second combustion chamber, in particular of the second injector, can only be increased if the internal combustion engine is not operated at maximum power, i.e., in particular under full load, and especially not with the maximum fuel injection rate of the majority of combustion chambers. If the internal combustion engine is not operated at maximum power, and especially not with the maximum fuel injection rate of the majority of combustion chambers, a reserve up to the maximum fuel injection rate of the majority of combustion chambers advantageously exists.

[0019] Tests and simulations revealed that, in the event of a first injector failure, a complete replenishment of the fuel injection mass via the second first injector is generally not necessary to prevent compressor pumping of the first exhaust gas turbocharger. Furthermore, it was determined that at an internal combustion engine output of up to 80%, a sufficient reserve of fuel injection rate is available to prevent compressor pumping.

[0020] Methods for detecting an injector failure in a combustion chamber are known in themselves, so they will not be discussed in further detail here.

[0021] Preferably, the first compressor and the second compressor are fluidly connected via a charge air cooler.

[0022] According to a further development of the invention, the first combustion chamber is continuously monitored for injector failure, and the first functional parameter of the first exhaust gas turbocharger is continuously compared with the compressor pumping limit. Advantageously, this achieves continuous monitoring of the first combustion chamber and ensures continuous operation of the first exhaust gas turbocharger without potential compressor pumping.

[0023] According to a further development of the invention, it is provided that all combustion chambers of the plurality of combustion chambers, in particular all injectors of the plurality of injectors, are monitored for injector failure, and that for all exhaust gas turbochargers the associated first functional parameter is compared with the compressor pumping limit.

[0024] In a particularly preferred embodiment of the method, all combustion chambers are continuously monitored for injector failure. Additionally, the first functional parameter assigned to each exhaust gas turbocharger is continuously compared with the compressor pumping limit. Advantageously, this achieves continuous monitoring of the internal combustion engine and ensures continuous operation of the engine without potential compressor pumping.

[0025] According to a further development of the invention, the first functional parameter is selected from a group consisting of an exhaust gas pressure, a turbine power of the first exhaust gas turbocharger and a compressor power of the first exhaust gas turbocharger.

[0026] Advantageously, in the event of an injector failure, particularly in the first combustion chamber, the exhaust pressure, especially the exhaust pressure at the first exhaust gas turbocharger, decreases, and consequently, so do the turbine and compressor outputs, especially those of the first exhaust gas turbocharger. This allows for a simple determination of whether the first operating parameter exceeds the compressor pumping limit.

[0027] According to a further development of the invention, a compressor pump is detected when the first functional parameter exceeds a predetermined characteristic curve, which is defined as the compressor pump limit, in a characteristic map. Advantageously, this allows for a more differentiated and precise determination of whether a compressor pump can occur or not.

[0028] According to a further development of the invention, a two-dimensional diagram of the first functional parameter and a pressure ratio is used as the characteristic map. In the preferred embodiment, the characteristic map has been created in advance, in particular on a test bench and / or by means of simulations, and stored in the control unit of the internal combustion engine.

[0029] According to a further development of the invention, at least one second functional parameter, selected from a group consisting of an air-fuel ratio, an exhaust gas temperature, and an exhaust gas blackening, is evaluated. Preferably, the fuel injection rate is adjusted and / or changed taking the second functional parameter into account.

[0030] The problem is also solved by creating a control device configured to carry out a method according to the invention or a method according to one or more of the embodiments described above. The advantages already explained in connection with the method arise particularly in connection with the control device. The control device is preferably designed as a control unit for an internal combustion engine, in particular as a so-called Engine Control Unit (ECU).

[0031] In a preferred embodiment, the method is implemented in the control unit as software or as a software extension, in particular as a software update. This allows an internal combustion engine to be operated easily using the method according to the invention or using a method according to one or more of the embodiments described above. Advantageously, the software extension, in particular the software update, can be installed on existing internal combustion engines, especially on the control unit of an internal combustion engine, thus ensuring efficient and safe operation of the internal combustion engine.

[0032] In this context, the invention also includes a computer program product which has machine-readable instructions according to which a method according to the invention or a method according to one or more of the previously described embodiments is carried out on a control device when the computer program product is running on the control device.

[0033] The problem is ultimately solved by creating an internal combustion engine with a first combustion chamber group and a second combustion chamber group. A first exhaust gas turbocharger is assigned to the first combustion chamber group, and a second exhaust gas turbocharger is assigned to the second combustion chamber group. The first combustion chamber group and the second combustion chamber group each have at least two combustion chambers. Furthermore, a first compressor of the first exhaust gas turbocharger and a second compressor of the second exhaust gas turbocharger are fluidically connected downstream of the compressors. The internal combustion engine also includes a control device according to the invention or a control device according to one or more of the previously described embodiments. In connection with the internal combustion engine, the advantages that have already been explained in connection with the method and the control device become particularly apparent.

[0034] Alternatively, the internal combustion engine can have more than two combustion chamber groups.

[0035] Preferably, the majority of combustion chamber groups have an identical number of combustion chambers.

[0036] Preferably, the control unit is operatively connected to the injectors and the exhaust gas turbochargers, in particular with at least one sensor for monitoring the exhaust gas turbochargers, and is configured for their respective control.

[0037] In a preferred embodiment, the internal combustion engine has twelve combustion chambers and four exhaust gas turbochargers. Each combustion chamber group consists of three combustion chambers.

[0038] In another preferred embodiment, the internal combustion engine has 16 combustion chambers and four exhaust gas turbochargers. Each combustion chamber group consists of four combustion chambers.

[0039] According to a further development of the invention, all compressors of the internal combustion engine are fluidically connected to each other via a charge air cooler downstream of the compressors. Advantageously, this cools the air heated by compression in addition to equalizing the pressure.

[0040] According to a further development of the invention, an internal combustion engine is provided with a first combustion chamber group, a second combustion chamber group, a third combustion chamber group, and a fourth combustion chamber group. A third exhaust gas turbocharger is assigned to the third combustion chamber group, and a fourth exhaust gas turbocharger is assigned to the fourth combustion chamber group. The first compressor of the first exhaust gas turbocharger, the second compressor of the second exhaust gas turbocharger, a third compressor of the third exhaust gas turbocharger, and a fourth compressor of the fourth exhaust gas turbocharger are fluidically connected to each other downstream of the compressors. Furthermore, a first exhaust gas path of the first combustion chamber group and a third exhaust gas path of the third combustion chamber group are fluidly connected to each other. Additionally, a second exhaust gas path of the second combustion chamber group and a fourth exhaust gas path of the fourth combustion chamber group are fluidly connected to each other.

[0041] Alternatively, the internal combustion engine can have more than four combustion chamber groups.

[0042] In a preferred embodiment, the first combustion chamber group and the third combustion chamber group form a first combustion chamber bank. Additionally, the second combustion chamber group and the fourth combustion chamber group form a second combustion chamber bank. Thus, the first combustion chamber bank and the second combustion chamber bank each have at least two exhaust gas turbochargers.

[0043] In a preferred embodiment, the internal combustion engine has twelve combustion chambers and four exhaust gas turbochargers. The first combustion chamber bank and the second combustion chamber bank each have six combustion chambers and two exhaust gas turbochargers. Thus, three combustion chambers are thermodynamically assigned to the turbine of each exhaust gas turbocharger.

[0044] In another preferred embodiment, the internal combustion engine has 16 combustion chambers and four exhaust gas turbochargers. The first combustion chamber bank and the second combustion chamber bank each have eight combustion chambers and two exhaust gas turbochargers. Thus, four combustion chambers are thermodynamically assigned to the turbine of each exhaust gas turbocharger.

[0045] In another preferred embodiment, the internal combustion engine has 20 combustion chambers and six exhaust gas turbochargers. The first combustion chamber bank and the second combustion chamber bank each have ten combustion chambers and three exhaust gas turbochargers. Thus, 3.5 combustion chambers are fluidically assigned to the turbine of each exhaust gas turbocharger.

[0046] According to a further development of the invention, the internal combustion engine has at least one fluid connection that fluidically connects the first exhaust gas path and the second exhaust gas path. Alternatively or additionally, the at least one fluid connection fluidly connects the third exhaust gas path and the fourth exhaust gas path. Advantageously, a pressure drop downstream of the combustion chambers, particularly due to an injector failure, is compensated by additionally achieving pressure equalization downstream of the combustion chambers by means of the fluid connection.

[0047] According to a further development of the invention, the fluid connection is selected from a group consisting of an O-shaped exhaust gas cross-connection, a U-shaped exhaust gas cross-connection, and an H-shaped exhaust gas cross-connection.

[0048] The O-shaped exhaust gas cross-connection is formed by a first fluid connection between the first and second exhaust gas paths and a second fluid connection between the third and fourth exhaust gas paths. The first, second, third, and fourth exhaust gas paths, the first fluid connection, and the second fluid connection, in particular from a spatial perspective, form an O-shaped flow-related connection, the so-called O-shaped exhaust gas cross-connection.

[0049] The U-shaped or H-shaped exhaust gas cross-connection is formed by a fluid connection between the first and second exhaust gas paths, or between the third and fourth exhaust gas paths. Depending on the spatial position of the fluid connection, the first, second, third, and fourth exhaust gas paths, and the fluid connection, form, particularly in spatial terms, a U-shaped flow path, the so-called U-shaped exhaust gas cross-connection, or an H-shaped flow path, the so-called H-shaped exhaust gas cross-connection. If one end of the fluid connection is connected to the respective exhaust gas paths in a transition region from the first to the third exhaust gas path, and the other end of the fluid connection is connected to the respective exhaust gas paths in a transition region from the second to the fourth exhaust gas path, the H-shaped exhaust gas cross-connection is created.Otherwise, a U-shaped exhaust gas cross-connection is formed.

[0050] According to a further development of the invention, an air filter is assigned to at least one exhaust gas turbocharger. Preferably, the air filter is arranged upstream of the compressor of the at least one exhaust gas turbocharger.

[0051] The invention will be explained in more detail below with reference to the drawing. The drawing shows: Fig. 1 a schematic representation of a first embodiment of an internal combustion engine, Fig. 2 a flowchart of an embodiment of a method for operating an internal combustion engine, Fig. 3 a schematic representation of a second embodiment of an internal combustion engine, and Fig. 4 a schematic representation of a third, fourth and fifth embodiment of an internal combustion engine.

[0052] Fig. Figure 1 shows a schematic representation of a first embodiment of an internal combustion engine 1. The internal combustion engine 1 has a first combustion chamber group 3.1, comprising a first combustion chamber 5.1, a second combustion chamber 5.2, a third combustion chamber 5.3, and a fourth combustion chamber 5.4, and a second combustion chamber group 3.2, which also comprises four combustion chambers 5. A first exhaust gas turbocharger 7.1 with a first compressor 9.1 is assigned to the first combustion chamber group 3.1. A second exhaust gas turbocharger 7.2 with a second compressor 9.2 is assigned to the second combustion chamber group 3.2. The first compressor 9.1 and the second compressor 9.2 are fluidically connected downstream of the compressors 9, thereby creating pressure equalization downstream of the compressors 9. Each combustion chamber 5 of the plurality of combustion chambers 5 has at least one injector.Furthermore, the internal combustion engine 1 has a control device 11 which is operatively connected, in a manner not explicitly shown, to each injector of the plurality of injectors and each exhaust gas turbocharger 7 of the plurality of exhaust gas turbochargers 7, in particular to each with a sensor for monitoring the respective exhaust gas turbocharger 7.

[0053] Preferably, the compressors 9 are fluidically connected to each other via a charge air cooler 13.

[0054] Preferably, at least one of the exhaust gas turbochargers 7 is associated with an air filter 15, which is arranged upstream of the compressor 9 of the at least one exhaust gas turbocharger 7. Particularly preferably, the first exhaust gas turbocharger 7.1 and the second exhaust gas turbocharger 7.2 are each associated with an air filter 15, which are arranged upstream of the first compressor 9.1 and the second compressor 9.2, respectively.

[0055] The control unit 11 is set up to carry out a Fig. 2. Method for operating the internal combustion engine 1.

[0056] Fig. Figure 2 shows a flowchart of an embodiment of a method for operating the internal combustion engine 1.

[0057] In step A, a combustion chamber 5 of the plurality of combustion chambers 5, in particular the first combustion chamber 5.1, is selected for monitoring. In step B, the selected combustion chamber 5, in particular the first combustion chamber 5.1, and especially the first injector, is monitored for injector failure. Preferably simultaneously, in step C, a first functional parameter of the exhaust gas turbocharger 7, which is assigned to the selected combustion chamber 5, in particular a first functional parameter of the first exhaust gas turbocharger 7.1, is monitored for compressor pumping. For this purpose, in step C1, the first functional parameter is recorded and in step C2 compared with a compressor pumping limit, in particular a predefined compressor pumping limit. In step D, it is checked whether an injector failure, in particular an injector failure in the first combustion chamber 5, has occurred in step B.1, is detected and whether the first functional parameter, in particular the first functional parameter of the first exhaust gas turbocharger 7.1, exceeds the compressor pumping limit.

[0058] If, in step B, an injector failure is detected, in particular an injector failure in the first combustion chamber 5.1, and in step C the first functional parameter, in particular the first functional parameter of the first exhaust gas turbocharger 7.1, exceeds the compressor pumping limit, in step E a fuel injection rate of the combustion chambers 5, which are assigned to the same combustion chamber group 3 as the selected combustion chamber 5, in particular the combustion chambers 5 of the first combustion chamber group 3.1, in particular the second combustion chamber 5.2, the third combustion chamber 5.3 and the fourth combustion chamber 5.4, is selected, in particular increased, such that compressor pumping is avoided.

[0059] If in step B an injector failure, in particular an injector failure in the first combustion chamber 5.1, is detected and in step C during the same evaluation, in particular simultaneously, the first functional parameter, in particular the first functional parameter of the first exhaust gas turbocharger 7.1, does not exceed the compressor pumping limit, nothing will be done.

[0060] If no injector failure is detected in step B, in particular no injector failure in the first combustion chamber 5.1, and in step C during the same evaluation, in particular simultaneously, the first functional parameter, in particular the first functional parameter of the first exhaust gas turbocharger 7.1, the compressor pumping limit, is exceeded, no action will be taken.

[0061] If no injector failure is detected in step B, in particular no injector failure in the first combustion chamber 5.1, and in step C during the same evaluation, in particular simultaneously, the first functional parameter, in particular the first functional parameter of the first exhaust gas turbocharger 7.1, the compressor pumping limit, is not exceeded, no action will be taken.

[0062] Optionally, after adjusting the fuel injection rate in step E, steps C and D are repeated to check whether the first functional parameter, in particular the first functional parameter of the first exhaust gas turbocharger 7.1, no longer exceeds the compressor pumping limit based on the change in the fuel injection rate.

[0063] Optionally, steps A to D or A to E will be repeated if no action is taken in step D, in particular if the fuel injection rate is not increased.

[0064] Preferably, the selected combustion chamber 5, in particular the first combustion chamber 5.1, is continuously monitored for injector failure. Additionally, the exhaust gas turbocharger 7 associated with the selected combustion chamber 5, in particular the first exhaust gas turbocharger 7.1, and in particular the first operating parameter of the associated exhaust gas turbocharger 7, is preferably continuously monitored for compressor pump failure.

[0065] Preferably, all combustion chambers 5 of the majority of combustion chambers 5 are monitored for injector failure. Additionally, the first functional parameter assigned to each exhaust gas turbocharger 7 is preferably compared with the compressor pumping limit.

[0066] Preferably, all combustion chambers 5, or the majority of combustion chambers 5, are continuously monitored for injector failure. Additionally, the first functional parameter assigned to each exhaust gas turbocharger 7 is preferably continuously compared with the compressor pumping limit.

[0067] Preferably, the first functional parameter is selected from a group consisting of an exhaust gas pressure, a turbine power, and a compressor power.

[0068] Preferably, in step C2, a compressor pump is optionally detected if the first functional parameter exceeds a predetermined characteristic curve, which is defined as the compressor pump limit, in a characteristic map. Preferably, the characteristic map is a two-dimensional diagram of the first functional parameter and a mass flow rate, in particular a reduced mass flow rate.

[0069] Preferably, in step E, at least one second functional parameter, selected from a group consisting of an air-fuel ratio, an exhaust gas temperature, and an exhaust gas blackening, is evaluated. The adjustment and / or modification of the fuel injection rate in step E is preferably carried out taking the second functional parameter into account.

[0070] Fig. Figure 3 shows a second embodiment of the internal combustion engine 1.

[0071] Identical and functionally equivalent elements are provided with the same reference symbols in all figures, so that reference is made to the preceding description in each case.

[0072] The internal combustion engine 1 has a first combustion chamber group 3.1, which comprises three combustion chambers 5, in particular the first combustion chamber 5.1 and the second combustion chamber 5.2; a second combustion chamber group 3.2, which comprises three combustion chambers 5; a third combustion chamber group 3.3, which comprises three combustion chambers 5; and a fourth combustion chamber group 3.4, which also comprises three combustion chambers 5. The first exhaust gas turbocharger 7.1 with the first compressor 9.1 is assigned to the first combustion chamber group 3.1. The second exhaust gas turbocharger 7.2 with the second compressor 9.2 is assigned to the second combustion chamber group 3.2. The third combustion chamber group 3.3 has a third exhaust gas turbocharger 7.3 with a third compressor 9.3. The fourth combustion chamber group 3.4 has a fourth exhaust gas turbocharger 7.4 with a fourth compressor 9.4. The first compressor 9.1, the second compressor 9.2, the third compressor 9.3 and the fourth compressor 9.4 are fluidically connected downstream of the compressors 9, preferably via the charge air cooler 13. Each combustion chamber 5 of the plurality of combustion chambers 5 has at least one injector. In addition, a first exhaust gas path 17.1 of the first combustion chamber group 3.1 and a third exhaust gas path 17.3 of the third combustion chamber group 3.3 are fluidly connected. Furthermore, a second exhaust gas path 17.2 of the second combustion chamber group 3.2 and a fourth exhaust gas path 17.4 of the fourth combustion chamber group 3.4 are fluidly connected.

[0073] In the internal combustion engine 1, the first combustion chamber group 3.1 and the third combustion chamber group 3.3 form a first combustion chamber bank 19.1, and the second combustion chamber group 3.2 and the fourth combustion chamber group 3.4 form a second combustion chamber bank 19.2.

[0074] Furthermore, the internal combustion engine 1 includes the control unit 11, which is operatively connected, in a manner not explicitly shown, to the plurality of injectors and the plurality of exhaust gas turbochargers 7. The control unit 11 is configured to carry out a method according to the invention or a method according to one or more of the embodiments described above.

[0075] Fig. Figure 4 shows three schematic representations of a third, fourth, and fifth embodiment of the internal combustion engine 1. These embodiments differ from the second embodiment of the internal combustion engine 1, shown in Figure 4. Fig. 2, simply by virtue of the fact that the internal combustion engine 1 has at least one fluid connection 21 which fluidically connects the first exhaust path 17.1 with the second exhaust path 17.2 and / or the third exhaust path 17.3 with the fourth exhaust path 17.4. For clarity, not all reference numerals are shown. The reference numerals not shown are accordingly derived in particular from Fig. 3.

[0076] In the third, fourth and fifth embodiments of the internal combustion engine 1, at least one fluid connection 21 connects the first combustion chamber bank 19.1 and the second combustion chamber bank 19.2 downstream of the combustion chambers 5 in a fluid flow-technical manner.

[0077] In Fig. 4 a) the first exhaust gas path 17.1, the second exhaust gas path 17.2, the third exhaust gas path 17.3, the fourth exhaust gas path 17.4 and the fluid connection 21 form a U-shaped exhaust gas cross connection 23.

[0078] In Fig. 4 b) the first exhaust gas path 17.1, the second exhaust gas path 17.2, the third exhaust gas path 17.3, the fourth exhaust gas path 17.4 and the fluid connection 21 form an H-shaped exhaust gas cross connection 25.

[0079] In Fig. 4 c) the first exhaust gas path 17.1, the second exhaust gas path 17.2, the third exhaust gas path 17.3, the fourth exhaust gas path 17.4 and the two fluid connections 21 form an O-shaped exhaust gas cross connection 27.

Claims

[1] Method for operating an internal combustion engine (1) with at least two exhaust gas turbochargers (7), wherein - a first combustion chamber group (3.1) is assigned a first exhaust gas turbocharger (7.1), wherein - a second exhaust gas turbocharger (7.2) is assigned to a second combustion chamber group (3.2), wherein - a first compressor (9.1) of the first exhaust gas turbocharger (7.1) and a second compressor (9.2) of the second exhaust gas turbocharger (7.2) are fluidically connected downstream of the compressors (9), wherein - the first combustion chamber group (3.1) has a first combustion chamber (5.1) and a second combustion chamber (5.2), wherein - each combustion chamber (5) of the plurality of combustion chambers (5) is assigned at least one injector, wherein - the first combustion chamber (5.1), in particular a first injector, is monitored for injector failure, wherein - at least one first operating parameter of the first exhaust gas turbocharger (7.1) is monitored for compressor pumping, wherein - if an injector failure is detected in the first combustion chamber (5.1), in particular of the first injector, and in addition the first operating parameter exceeds a compressor pumping limit, a fuel injection rate of the second combustion chamber (5.2) is selected such that compressor pumping of the first exhaust gas turbocharger (7.1) is avoided. [2] Method according to claim 1, wherein the first combustion chamber (5.1) is continuously monitored for injector failure, wherein the first operating parameter of the first exhaust gas turbocharger (7.1) is continuously compared with the compressor pumping limit. [3] Method according to one of the preceding claims, wherein all combustion chambers (5), in particular all injectors, are monitored for injector failure, the first functional parameter of all exhaust gas turbochargers (7) being compared with the compressor pumping limit. [4] Method according to one of the preceding claims, wherein the first functional parameter is selected from a group consisting of an exhaust gas pressure, a turbine power and a compressor power. [5] Method according to one of the preceding claims, wherein a compressor pump is detected when the first functional parameter exceeds a predetermined characteristic curve, which is defined in particular as the compressor pump limit in a characteristic map. [6] Method according to one of the preceding claims, wherein the characteristic map is a two-dimensional diagram of the first function parameter and a pressure ratio. [7] Method according to one of the preceding claims, wherein at least one second functional parameter selected from a group consisting of an air-fuel ratio, an exhaust gas temperature and an exhaust gas blackening is evaluated. [8] Control device (11) configured to carry out a procedure according to any of the preceding claims. [9] Internal combustion engine (1) with - a first combustion chamber group (3.1) and a second combustion chamber group (3.2), - a first exhaust gas turbocharger (7.1) and a second exhaust gas turbocharger (7.2), and - a control device (11) according to claim 8, wherein - the first combustion chamber group (3.1) and the second combustion chamber group (3.2) each have at least two combustion chambers (5), wherein - the first combustion chamber group (3.1) is assigned to the first exhaust gas turbocharger (7.1), wherein - the second combustion chamber group (3.2) is assigned the second exhaust gas turbocharger (7.2), whereby - a first compressor (9.1) of the first exhaust gas turbocharger (7.1) and a second compressor (9.2) of the second exhaust gas turbocharger (7.2) are fluidically connected downstream of the compressor (9). [10] Internal combustion engine (1) according to claim 9, wherein all compressors (9) are fluidically connected to each other via a charge air cooler (13) downstream of the compressors (9). [11] Internal combustion engine (1) according to claim 9 or claim 10, comprising - the first combustion chamber group (3.1), the second combustion chamber group (3.2), a third combustion chamber group (3.3) and a fourth combustion chamber group (3.4), - the first exhaust gas turbocharger (7.1), the second exhaust gas turbocharger (7.2), a third exhaust gas turbocharger (7.3) and a fourth exhaust gas turbocharger (7.4), wherein - the first combustion chamber group (3.1) is assigned to the first exhaust gas turbocharger (7.1), wherein - the second combustion chamber group (3.2) is assigned the second exhaust gas turbocharger (7.2), whereby - the third combustion chamber group (3.3) is assigned the third exhaust gas turbocharger (7.3), wherein - the fourth combustion chamber group (3.4) is assigned the fourth exhaust gas turbocharger (7.4), whereby - the first compressor (9.1) of the first exhaust gas turbocharger (7.1), the second compressor (9.2) of the second exhaust gas turbocharger (7.2), a third compressor (9.3) of the third exhaust gas turbocharger (7.3) and a fourth compressor (9.4) of the fourth exhaust gas turbocharger (7.4) are fluidically connected downstream of the compressors (9), wherein - a first exhaust gas path (17.1) of the first combustion chamber group (3.1) and a third exhaust gas path (17.3) of the third combustion chamber group (3.3) are fluidically connected, wherein - a second exhaust gas path (17.2) of the second combustion chamber group (3.2) and a fourth exhaust gas path (17.4) of the fourth combustion chamber group (3.4) are fluidically connected. [12] Internal combustion engines (1) according to any one of claims 9 to 11 with at least one fluid connection (21) which fluidly connects the first exhaust gas path (17.1) of the first combustion chamber group (3.1) with the second exhaust gas path (17.2) of the second combustion chamber group (3.2) and / or the third exhaust gas path (17.3) of the third combustion chamber group (3.3) with the fourth exhaust gas path (17.4) of the fourth combustion chamber group (3.4). [13] Internal combustion engine (1) according to claim 12, wherein the fluid connection (21) is selected from a group consisting of an O-shaped exhaust cross connection (27), a U-shaped exhaust cross connection (23), and an H-shaped exhaust cross connection (25). [14] Internal combustion engine (1) according to one of claims 9 to 13, wherein at least one exhaust gas turbocharger (7) is associated with an air filter (15), which is arranged in particular upstream of the compressor (9) of the at least one exhaust gas turbocharger (7).

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