System and method for detecting, diagnosing, and responding to fuel leaks for hydrogen combustion engines

Abstract

Fuel leak detection, fuel injector leak detection, diagnosis, and / or response to the same are disclosed for a spark-ignited combustion engine that combusts hydrogen fuel. The response to fuel leak detection varies depending on the compartment of the engine in which the leakage is detected. One or more operating parameters of the engine are adjusted to reduce the amount of hydrogen in the one or more compartments of the engine. Fuel injector leak detection is performed during motoring of the engine while exhaust gas characteristic are monitored via a sensor in order to detect the presence of hydrogen in the exhaust system. Variable valve train technology may also be used to diagnose the source of the fuel injector leakage in response to determining a leak condition exists.

Description

SYSTEM AND METHOD FOR DETECTING, DIAGNOSING, AND RESPONDING TOFUEL LEAKS FOR HYDROGEN COMBUSTION ENGINESCROSS-REFERENCE TO RELATED APPLICATIONS:

[0001] The present application claims priority to, and the benefit of the filing dates of, U.S Provisional App. Ser. No. 63 / 514,165 filed on July 18, 2023, and U.S. Provisional App. Ser. No. 63 / 582,656 filed on September 14, 2023, each of which is incorporated herein by reference.TECHNICAL FIELD

[0002] The present application relates to apparatuses, methods, systems, and techniques for fuel leak detection, diagnosis, and / or response to fuel leakage for internal combustion engines that combust hydrogen fuel.BACKGROUND

[0003] Internal combustion engines may experience fuel leaks and / kor fuel injector leaks during operation, which effects combustion of the air-fuel mixture and may result in fuel collecting in areas of the engine not intended to receive or store fuel. Various attempts have been made to detect and / or diagnose fuel leaks and fuel injector leaks. Existing approaches suffer from a number of disadvantages and shortcomings including unsuitability for detecting and / or responding to fuel leakage. There remains a significant need for the unique apparatuses, methods, systems, and techniques of the present disclosure.DISCLOSURE OF EXAMPLE EMBODIMENTS

[0004] For the purposes of clearly, concisely, and exactly describing example embodiments of the present disclosure, the manner, and process of making and using the same, and to enable the practice, making and use of the same, reference will now be made to certain example embodiments, including those illustrated in the figures, and specific language will be used to describe the same. It shall nevertheless be understood that no limitation of the scope of the invention is thereby created, and that the invention includes and protects such alterations, modifications, and further applications of the example embodiments as would occur to one skilled in the art.SUMMARY

[0005] Some embodiments include unique apparatuses for fuel leak detection and / or fuel leak response for hydrogen combustion engines. Some embodiments include unique methods for fuel leak detection and / or fuel leak response for hydrogen combustion engines. Some embodiments include unique systems for fuel leak detection and / or fuel leak response for hydrogen combustion engines. Some embodiments include unique techniques for fuel leak detection and / or fuel leak response for hydrogen combustion engines. Further embodiments, forms, objects, features, advantages, aspects, and benefits shall become apparent from the following description and drawings.

[0006] Some embodiments include unique apparatuses for fuel injector leak detection and / or fuel injector leak diagnosis for hydrogen combustion engines. Some embodiments include unique methods for fuel injector leak detection and / or fuel injector leak diagnosis for hydrogen combustion engines. Some embodiments include unique systems for fuel injector leak detection and / or fuel injector leak diagnosis for hydrogen combustion engines. Some embodiments include unique techniques for fuel injector leak detection and / or fuel injector leak diagnosis for hydrogen combustion engines. Further embodiments, forms, objects, features, advantages, aspects, and benefits shall become apparent from the following description and drawings.BRIEF DESCRIPTION OF THE DRAWINGS

[0007] FIG. 1 is a schematic diagram illustrating certain aspects of an example powertrain system.

[0008] FIG. 2 is a schematic diagram further illustrating certain aspects of an example powertrain system.

[0009] FIG. 3 is a flow diagram illustrating certain aspects of a fuel detection and response process.

[0010] FIG. 4 is a flow diagram illustrating certain aspects of another fuel detection and response process.

[0011] FIG. 5 is a flow diagram illustrating certain aspects of another fuel detection and response process.

[0012] FIG. 6 is a schematic diagram illustrating certain aspects of another embodiment of an example powertrain system.

[0013] FIG. 7 is a flow diagram illustrating certain aspects of a fuel injector leakage detection process.

[0014] FIG. 8 is a flow diagram illustrating certain aspects of a fuel injector leakage diagnosis process.DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS

[0015] With reference to FIG. 1, there is illustrated an example powertrain system 10 (also referred to herein as system 10) comprising an engine 12 and a fueling system 14. Fueling system 14 is adapted and configured to supply gaseous hydrogen to engine 12 for combustion in one or more combustion chambers of engine 12. In some embodiments, fueling system 14 may be additionally adapted and configured to supply one or more other fuels for combustion to engine 12 in combination with gaseous hydrogen. For example, engine 12 may run solely on hydrogen, on diesel and hydrogen, on natural gas and hydrogen, on propane and hydrogen, etc.

[0016] In an embodiment, system 10 includes an electronic control system (ECS) 80 with at least one electronic control unit (ECU) 82 configured to operate engine 12 with one or more operating parameters. The ECU 82 monitors one or more compartments of engine 12 for hydrogen during operation of engine 12. In an embodiment, the one or more compartments do not include the combustion chambers or fuel system of engine 12. The ECU 82 determines a hydrogen amount in the one or more compartments exceeds a predetermined threshold, and adjusts the one or more operating parameters that control operation of the engine in response to the hydrogen amount exceeding the predetermined threshold to reduce the hydrogen in the one or more compartments.

[0017] In the illustrated embodiment, engine 12 comprises a plurality of cylinders 16 (also referred to as combustion chambers) of a reciprocating piston-in-cylinder type which are configured to generate mechanical power from the combustion of gaseous fuel supplied by fuel injectors 18a, 18b, 18c, 18d, 18e, 18f Fuel injectors 18a, 18b, 18c, 18d, 18e, 18f are collectively referred to herein as fuel injector or fuel injectors 18, and may be provided in any suitable number based on the number of cylinders 16. Although six cylinders 16 are illustrated in FIG. 1, any number of cylinders 16, each with a fuel injector 18, is contemplated herein. System 10 may be provided in a number of forms including as a prime mover system (or component of a prime mover system) of vehicle, a genset, other power-load system.

[0018] Fuel injectors 18 are in fluid communication with respective combustion chambers of cylinders 16 of the engine 12 and are structured to inject gaseous fuel. In the illustrated embodiment, fuel injectors 18 are configured and provided as direct fuel injectors configured to inject fuel directly into respective combustion chambers of cylinders 16. Other embodimentscontemplate injectors 18 are port injectors that inject fuel directly into ports of intake manifold 20 leading to respective combustion chambers of cylinders 16. Each cylinder 16 may also include a spark plug 58 for spark ignition of the air-fuel mixture in the combustion chambers of cylinders 16. It should be appreciated that engine 12 may include fewer or greater numbers of fuel injectors 18 and cylinders 16 than illustrated that are arranged and configured in a variety of manners. In an embodiment, the fuel injectors 18 and / or spark plugs 58 are controlled to change combustion processes and / or temperature to reduce hydrogen in one or more compartments of engine 12, as discussed further below.

[0019] In the illustrated embodiment, engine 12 of system 10 further includes an exhaust manifold 22 connected to receive an output from cylinder 16 and provide the output to exhaust system 24. Exhaust system 24 may include an exhaust conduit 26, turbocharger 28, and an aftertreatment system 30 downstream of turbocharger 28. Turbocharger 28 may include a turbine 32 with a wastegate 34. In another embodiment, turbine 32 includes a variable inlet to control exhaust flow therethrough, such as a variable geometry turbine (VGT). In another embodiment, turbocharger 28 is omitted, and / or an exhaust throttle 35 is provided. In an embodiment, the exhaust throttle 35, VGT type turbine 32, or wastegate 34 is controlled to change the combustion processes, temperature and / or increase air flow to reduce hydrogen in one or more compartments of engine 12, as discussed further below.

[0020] With further reference to FIG. 2, engine 12 includes a crankcase 66 for storing and circulating lubrication fluid in an engine block that houses cylinders 16 and associated pistons. Engine 12 also includes a valve cover 68 as part of a cylinder head mounted on the engine block containing crankcase 66. In an embodiment, engine 12 includes more than valve cover, such as may be provide for an engine with multiple cylinder banks, and / or for a V6 engine, a V8 engine, a V10 engine, a V12 engine, a V16 engine, etc.

[0021] A breather system 70 connects an interior of valve cover 68 with an interior of crankcase 66. Breather system 70 includes a breather 72 that separates gases from fluids from valve cover 68, and provides the separated fluid to crankcase 66 and provides the separated gases for venting to the intake system or other location. Breather system 70 may also include one or more of a vacuum pump 74 and an air pump 76 that can be controlled to pull or push air flow through crankcase 66 and / or valve cover 68 to reduce hydrogen in the one or morecompartments, as discussed further below.

[0022] Engine 12 of system 10 also includes an intake system 40. In an embodiment, turbocharger 38 includes a compressor 36 in intake system 40 to receive the intake air flow for compression. In an embodiment, intake system 40 may include one or more of a charge air cooler (CAC) 42, an intake throttle 44, and an intake conduit 46 connecting these components to intake manifold 20. CAC 42 may include a CAC bypass 43 and a CAC valve 45 to control the amount of intake air flow through CAC 42. Other embodiments contemplate other intake system components, and / or omission of one or more of the disclosed components. CAC bypass 43, CAC valve 45, and / or intake throttle 44 can be controlled to change the combustion processes, temperature, and / or increase air flow to reduce hydrogen in the one or more compartments, as discussed further below.

[0023] Still other embodiments contemplate an exhaust gas recirculation (EGR) system 86 to provide exhaust produced from one or more of cylinders 16 to intake system 40. EGR system 86 includes an EGR cooler 87, and EGR cooler bypass 88, and an EGR valve 89 to control a temperature and / or amount of EGR flow through EGR system 86. EGR flow through EGR cooler 87 and / or EGR bypass 88 can be controlled to change the combustion processes, temperature, and / or increase air flow to reduce hydrogen in the one or more compartments, as discussed further below.

[0024] In an embodiment, system 10 includes a variable valve timing / actuation (VVT or VVA) system 60 in operable engagement with cylinders 16. As described herein, the VVT / VVA system 60 refers to any mechanism that can change the lift, duration and / or timing of the opening / closing of intake valves and / or exhaust valves of cylinders 16 during operation of the engine 12. The VVT / VVA system 60 can be provided as any suitable mechanical device (camless or otherwise), electro-hydraulic device, or the like, or a combination thereof. In one embodiment, the VVT system 60 can be controlled to selectively isolate one of more of cylinders 16 from providing a flow output to exhaust system 24. For example, VVT / VVA system 60 can be controlled to change the combustion processes and / or increase the air flow through engine 12 to reduce a hydrogen amount in the one or more compartments, as discussed further below.

[0025] In some embodiments, fueling system 14 may include additional elements such as a compressor configured to compress gaseous fuel received from a fuel tank supply 62 andprovided compressed gaseous fuel to one or more rails, and / or an accumulator as well as electronically controllable valve or valves 64 configured to control supply of gaseous fuel to and from the accumulator and / or the one or more rails. In any event, fueling system 14 can be controlled to be isolated or shut-off during operation of engine 12 so that engine 12 operates without fueling, such as under a motoring condition. In the motoring condition, air flow from intake system 40 provided to cylinders 12, and the air flow is output to exhaust system 24. However, fuel flow through injectors 18 is cut-off, either at valve 64 or at each injector 18, so that no hydrogen fuel is injected into the combustion chambers of cylinders 16 during the motoring condition.

[0026] Engine 12 may further include one or more sensors 50, 52, 54, 56 configured to sense or detect one or more characteristics and / or constituents of the gases in one or more compartments of engine 12 associated with sensors 50, 52, 54, 56 and provide one or more outputs to allow a hydrogen in the associated compartment to be monitored and / or a hydrogen amount in the compartment to be determined. In an embodiment, the one or more compartments include intake manifold 20, exhaust manifold 22, crankcase 66, and / or valve cover 68. In an embodiment, the one or more compartments include a vehicle cab, a battery enclosure, an aftertreatment system and / or aftertreatment component, and / or under a hood of a vehicle.

[0027] In an embodiment, sensor 50 is associated with intake manifold 20 of engine 12 to sense or detect one or more characteristics and / or constituents of the gases in intake manifold 20. In an embodiment, sensor 52 is associated with exhaust manifold 22 of engine 12 to sense or detect one or more characteristics and / or constituents of the gases in exhaust manifold 22. In an embodiment, sensor 54 is associated with crankcase 66 of engine 12 to sense or detect one or more characteristics and / or constituents of the gases in crankcase 66. In an embodiment, sensor 56 is associated with valve cover 68 of engine 12 to sense or detect one or more characteristics and / or constituents of the gases in valve cover 68. Other sensors may be provided and associated with other compartments disclosed herein.

[0028] In an embodiment, one or more of sensors 50, 52, 54, 56 is a hydrogen sensor. In an embodiment, one or more of sensors 50, 52, 54, 56 is a NOx sensor cross-sensitive to hydrogen. In an embodiment, one or more of sensors 50, 52, 54, 56 is an oxygen sensor cross-sensitive to hydrogen. In an embodiment, one or more of sensors 50, 52, 54, 56 is a carbon monoxide sensorcross-sensitive to hydrogen. In an embodiment, one or more of sensors 50, 52, 54, 56 is a carbon dioxide sensor cross-sensitive to hydrogen.

[0029] In other embodiments, one or more of sensors 50, 52, 54, 56 represents a virtual sensor. For example, a hydrogen amount in the associated compartment is predicted based on one or more models associated with the hydrogen fuel. The one or more models may be based at least in part on the amount of hydrogen provided by the fuel system 14, the amount of hydrogen combusted in cylinders 16, variations in flow of the hydrogen fuel, pressure decay in one or more components of the hydrogen fuel system 14, and / or variation in torque output from engine 12.

[0030] System 10 further includes ECS 80 in communication with engine 12 and configured to control one or more aspects of engine 12, including controlling the injection of fuel into engine 12 via the fuel injectors 18 and sparking timing with spark plugs 58. Accordingly, ECS 80 may be in communication with the fuel injectors 18 and configured to command each fuel injector 18 on and off at prescribed times to inject fuel into the engine 12 as desired for ignition with spark plugs 58 at a desire ignition timing. ECS 80 include at least one ECU 82 configured to execute operations of ECS 80 as described further herein and, in some embodiment, may include additional ECUs configured to execute operations of ECS 80 as described further herein.

[0031] ECS 80 may be further structured to control other operating parameters of engine 12, which may include aspects of engine 12 that may be controlled with an actuator activated by ECS 80. For example, ECS 80 may be in communication with actuators and sensors for receiving and processing sensor input and transmitting actuator output signals. Actuators that control operating parameters of engine 12 may include, but are not limited to, fuel injectors 18, spark plugs 58, VVT / VVA system 60, intake throttle 44, exhaust throttle 35, VGT turbine 32 or wastegate 34, CAC valve 45 and CAC bypass 43, EGR valve 89 and EGR bypass 88, and / or a speed of engine 12. The sensors may include any suitable devices to monitor operating parameters and functions of the system 10. For example, the sensors may include one or more of exhaust sensors 50, 52, 54, 56 in communication with one or more of the compartments provided by intake manifold 20, exhaust manifold 22, crankcase 66, and / or valve cover 68.

[0032] In at least one embodiment, system 10 may include one or more sensors 50, 52, 54, 56 in communication with the ECS 80 and structured to determine characteristics of gases within exhaust gases within intake manifold 20, exhaust manifold 22, crankcase 66, and / or valve cover68. Tn at least one embodiment of system 10, one or more sensors 50, 52, 54, 56 in communication with the ECS 80 represents a virtual sensor that determines an amount of hydrogen in the associated compartment based on an algorithm for predicting a hydrogen amount or level in the associated compartment.

[0033] As will be appreciated by the description that follows, the techniques described herein relating to fuel leak detection and / or control of operating parameters of engine 12 can be implemented in ECS 80, which may include one or more controllers for controlling different aspects of the system 10. In one form, the ECS 80 comprises one or more ECU’s 82 such as an engine control unit or engine control module. The ECS 80 may be comprised of digital circuitry, analog circuitry, or a hybrid combination of both of these types. Also, the ECS 80 may be programmable, an integrated state machine, or a hybrid combination thereof. The ECS 80 may include one or more Arithmetic Logic Units (ALUs), Central Processing Units (CPUs), memories, limiters, conditioners, fdters, format converters, or the like which are not shown to preserve clarity. In one form, the ECS 80 is of a programmable variety that executes algorithms and processes data in accordance with operating logic that is defined by programming instructions (such as software or firmware). Alternatively or additionally, operating logic for the ECS 80 may be at least partially defined by hardwired logic or other hardware.

[0034] In addition to the types of sensors described herein, any other suitable sensors and their associated parameters may be encompassed by the system and methods. Accordingly, the sensors may include any suitable device used to sense any relevant physical parameters including electrical, mechanical, and chemical parameters of system 10. As used herein, the term sensors may include any suitable hardware and / or software used to sense or estimate any engine system parameter and / or various combinations of such parameters either directly or indirectly.

[0035] With reference to FIG. 3, there is illustrated a flow diagram of a process 300 for detecting and / or reacting to a fuel leak in engine 12 with an electronic control system (e.g, ECS 80 or another electronic control system), in operative communication with a fueling system (e.g., fueling system 14 or another fueling system). Process 300 may be implemented in and performed by one or more components of an electronic control system such as one or more electronic control units (e.g., ECU 82 and / or other electronic control units) and / or by other electronic control system components.

[0036] Process 300 begins at operation 302, which operates the engine 12 using combustion of hydrogen fuel from fuel system 14. Process 300 continues at operation 304 to monitor hydrogen in one or more compartments of engine 12, such as intake manifold 20, exhaust manifold 22, crankcase 66, and / or valve cover 68. For example, one or more of sensors 50, 52, 54, 56 can be used to physically monitor hydrogen levels in the associated one or more compartments, or predict hydrogen levels in one or more of the associated engine compartments.

[0037] Process 300 continues at conditional 306 to determine if the hydrogen level or amount in one or more of the compartments of engine 12 is greater than a predetermined threshold. In an embodiment, the predetermined threshold is associated with a flammability limit for hydrogen gas. If conditional 306 is NO, process 300 returns to operation 304. If conditional 306 is YES, process 300 continues at operation 308 to adjust at least one operating parameter of engine 12 to reduce the hydrogen amount in the one or more compartments.

[0038] If the hydrogen amount still exceeds the predetermined threshold after adjusting one of the one or more operating parameters of engine 12, one or more additional operating parameters can be adjusted to reduce the hydrogen amount. In an embodiment, once the leakage condition is determined, one or more further actions can be taken. For example, a warning light can be illuminated and / or a fault code can be generated by ECU 82. In an embodiment, the hydrogen amount in the one or more compartments is continually monitored.

[0039] With reference to FIG. 4, there is illustrated a flow diagram of a process 400 for detecting a hydrogen fuel leak and / or reacting to the same. Process 400 begins at operation 402, which monitors for the presence of hydrogen in one or more compartments of engine 12, such as intake manifold 20 and / or exhaust manifold 22, while operating engine 12 with hydrogen fuel. For example, one or more of sensors 50, 52 can be used to physically monitor hydrogen levels in the associated intake manifold 20 and / or exhaust manifold 22, or hydrogen levels can be predicted in intake manifold 20 and / or exhaust manifold 22.

[0040] Process 400 continues at conditional 404 to determine if the hydrogen level or amount in intake manifold 20 and / or exhaust manifold 22 of engine 12 is greater than a predetermined threshold. In an embodiment, the predetermined threshold is associated with a flammability limit for hydrogen gas. If conditional 404 is NO, process 400 returns to operation 402. If conditional 404 is YES, process 400 continues at operation 406 to adjust at least oneoperating parameter of engine 12 to reduce the hydrogen amount in the intake manifold 20 and / or exhaust manifold 22.

[0041] Operation 406 can include for example, adjusting one or more actuators or operating levers of engine 12 to reduce the hydrogen amount in intake manifold 20 and / or exhaust manifold 22 by changing the combustion process, temperature conditions, and / or air flow through engine 12 to reduce hydrogen. Operation 406 can include adjusting the intake throttle 44 position; exhaust throttle 35 position; inlet position of a VGT type turbine 32; flow through CAC 42, CAC bypass 43, and CAC valve 45; flow through EGR cooler 87, EGR bypass 88, and EGR valve 89; settings for intake valve and / or exhaust valve opening / closing timing with VVA / VVT system 60; speed of engine 12; fuel injection timing with injectors 18; and / or spark timing with spark plugs 58. Operation 406 can include operating engine 12 under motoring conditions.

[0042] With reference to FIG. 5, there is illustrated a flow diagram of a process 500 for detecting a hydrogen fuel leak and / or reacting to the same. Process 500 begins at operation 502, which monitors for the presence of hydrogen in one or more compartments of engine 12, such as crankcase 66 and / or valve cover 68, while operating engine 12 with hydrogen fuel. For example, one or more of sensors 54, 56 can be used to physically monitor hydrogen levels in the associated crankcase 66 and / or valve cover 68, or hydrogen levels can be predicted in crankcase 66 and / or valve cover 68.

[0043] Process 500 continues at conditional 504 to determine if the hydrogen level or amount in one or more of the crankcase 66 and valve cover 68 of engine 12 is greater than a predetermined threshold. In an embodiment, the predetermined threshold is associated with a flammability limit for hydrogen gas. If conditional 504 is NO, process 500 returns to operation 502. If conditional 504 is YES, process 500 continues at operation 506 to adjust at least one operating parameter of engine 12 to reduce the hydrogen amount in the crankcase 66 and / or valve cover 68.

[0044] Operation 506 can include for example, adjusting one or more of vacuum pump 74 and air pump 76 to reduce the hydrogen amount in crankcase 66 and / or valve cover 68 through breather system 70. Operation 506 can include activating the vacuum pump 174 to pull hydrogen from crankcase 66 and / or valve cover 68 through breather 72. Operation 506 can include activating air pump 176 to push hydrogen from crankcase 66 and / or valve cover 68through breather 72. Other means for pulling or pushing hydrogen from crankcase 66 and / or valve cover 68 are also contemplated.

[0045] With reference to FIG. 6, there is illustrated another example powertrain system 610 (also referred to herein as system 610) comprising an engine 612 and a fueling system 614. Fueling system 614 is adapted and configured to supply gaseous hydrogen for combustion to engine 612. In some embodiments, fueling system 614 may be additionally adapted and configured to supply one or more other fuels for combustion to engine 612 in combination with gaseous hydrogen.

[0046] Engine 612 comprises a plurality of cylinders 616 (also referred to as combustion chambers) of a reciprocating piston-in-cylinder type which are configured to generate mechanical power from the combustion of gaseous fuel supplied by fuel injectors 618a, 618b, 618c, 618d, 618e, 618f. Fuel injectors 618a, 618b, 618c, 618d, 618e, 618f are collectively referred to herein as fuel injector or fuel injectors 618, and may be provided in any suitable number based on the number of cylinders 616. Although six cylinders 616 are illustrated in FIG. 6, any number of cylinders 616, each with a fuel injector 618, is contemplated herein. System 610 may be provided in a number of forms including as a prime mover system (or component of a prime mover system) of vehicle, a genset, other power-load system.

[0047] Fuel injectors 618 are in fluid communication with respective combustion chambers of cylinders 616 of the engine 612 and are structured to inject gaseous fuel. In the illustrated embodiment, fuel injectors 618 are configured and provided as direct fuel injectors configured to inject fuel directly into respective combustion chambers of cylinders 616. Other embodiments contemplate injectors 618 are port injectors that inject fuel directly into ports of intake manifold 620 leading to respective combustion chambers of cylinders 616. Each cylinder 616 may also include a spark plug 658 for spark ignition of the air-fuel mixture in the combustion chambers of cylinders 616. It should be appreciated that engine 612 may include fewer or greater numbers of fuel injectors 618 and cylinders 616 than illustrated that are arranged and configured in a variety of manners.

[0048] In the illustrated embodiment, system 610 further includes an exhaust manifold 622 connected to receive an output from cylinder 616 and provide the output to exhaust system 624. Exhaust system 624 may include an exhaust conduit 626, turbocharger 628, and anaftertreatment system 630 downstream of turbocharger 628. Turbocharger 628 may include a turbine 632 with a wastegate 634. In another embodiment, turbine 632 includes a variable inlet to control exhaust flow therethrough. In another embodiment, turbocharger 628 is omitted.

[0049] Exhaust system 624 may further include one or more sensors 650, 652, 654, 656 configured to sense or detect one or more characteristics and / or constituents of the exhaust or air flow through exhaust system 624. In an embodiment, sensor 650 is a hydrogen sensor, sensor 652 is a NOx sensor, and sensor 654 is an oxygen sensor. Each of sensors 650, 652, 654 is located upstream of turbocharger 628 and downstream of exhaust manifold 622 and / or engine 612. In an embodiment, sensor 656 is a NOx sensor downstream of aftertreatment system 630. As discussed further below, any one or combination of sensors 650, 652, 654, 656 may be used to sense one or more characteristics and / or constituents in the exhaust system 624 to detect leakage of one or more of fuel injectors 618. In other embodiments, one or more of sensors 650, 652, 654, 656 is omitted from system 610, or is provided and not involved in detecting leakage from fuel injectors 618.

[0050] System 610 also includes an intake system 640. In an embodiment, turbocharger 638 includes a compressor 636 in intake system 640 to receive the intake air flow for compression. In an embodiment, intake system 640 may include one or more of a charge air cooler 642, an intake throttle 644, and an intake conduit 646 connecting these components to intake manifold 620. Other embodiments contemplate other intake system components, and / or omission of one or more of the disclosed components. Still other embodiments contemplate an exhaust gas recirculation system to provide exhaust produced from one or more of cylinders 616 to intake system 640.

[0051] In an embodiment, system 610 includes a variable valve train (VVT) system 660 in operable engagement with cylinders 616. As described herein, the VVT system 660 refers to any mechanism that can change the lift, duration and / or timing of the intake valves and / or exhaust valves of cylinders 616 during operation of the engine 612. The VVT system 660 can be provided as any suitable mechanical device (camless or otherwise), electro-hydraulic device, or the like, or a combination thereof. In one embodiment, the VVT system 660 can be controlled to selectively isolate one of more of cylinders 616 from providing a flow output to exhaust system 624. For example, VVT system can be controlled to maintain the exhaust valve or valves of aselected cylinder in a closed condition for a period of time.

[0052] In some embodiments, fueling system 614 may include additional elements such as a compressor configured to compress gaseous fuel received from a fuel tank supply 662 and provided compressed gaseous fuel to one or more rails, and / or an accumulator as well as electronically controllable valve or valves 664 configured to control supply of gaseous fuel to and from the accumulator and / or the one or more rails. In any event, fueling system 614 can be controlled to be isolated or shut-off during operation of engine 612 so that engine 612 operates under a motoring condition. In the motoring condition, air flow from intake system 640 is provided to cylinders 612, and the air flow is output to exhaust system 624. However, fuel flow through injectors 618 is cut-off, either at valve 664 or at each injector 618, so that no hydrogen fuel is injected into the combustion chambers of cylinders 616 during the motoring condition.

[0053] System 610 further includes an electronic control system (ECS) 680 in communication with engine 612 and configured to control one or more aspects of engine 612, including controlling the injection of fuel into engine 612 via the fuel injectors 618 and controlled VVT system 660. Accordingly, ECS 680 may be in communication with the fuel injectors 618 and configured to command each fuel injector 618 on and off at prescribed times to inject fuel into the engine 612 as desired. ECS 680 include at least one electronic control unit (ECU) 682 configured to execute operations of ECS 680 as described further herein and, in some embodiment, may include additional ECUs configured to execute operations of ECS 680 as described further herein.

[0054] ECS 680 may be further structured to control other parameters of engine 612, which may include aspects of engine 612 that may be controlled with an actuator activated by ECS 680. For example, ECS 680 may be in communication with actuators and sensors for receiving and processing sensor input and transmitting actuator output signals. Actuators may include, but not be limited to, fuel injectors 618 and VVT system 660. The sensors may include any suitable devices to monitor operating parameters and functions of the system 10. For example, the sensors may include one or more of exhaust sensors 650, 652, 654, 656 in communication with exhaust system 624.

[0055] In at least one embodiment, system 610 may include one or more exhaust sensors 650, 652, 654, 656 in communication with the ECS 680 and structured to determinecharacteristics of exhaust gases generated and expelled by the cylinders 616 of engine 612. In at least one embodiment, system 610 may include one or more exhaust sensors 650, 652, 654, 656 in communication with the ECS 680 and structured to determine characteristics of the air flow expelled by the cylinders 616 of engine 612 during a motoring condition in which fuel is cut-off from injectors 618. In one embodiment, sensor 650 is a hydrogen sensor configured to directly detect the presence and / or amount of hydrogen in the exhaust system 624. In embodiment, sensor 652 and / or sensor 656 is a NOx sensor, and may detect the presence and / or amount of hydrogen in the exhaust system 624 due to its cross-sensitivity to hydrogen. In an embodiment, sensor 654 is an oxygen sensor, and may detect the presence and / or amount of hydrogen in the exhaust system 624 due to its cross-sensitivity to hydrogen.

[0056] As will be appreciated by the description that follows, the techniques described herein relating to fuel injector leak detection or fuel injector leak diagnosis can be implemented in ECS 680, which may include one or more controllers for controlling different aspects of the system 610. In one form, the ECS 680 comprises one or more electronic control units (ECU) such as an engine control unit or engine control module. The ECS 680 may be comprised of digital circuitry, analog circuitry, or a hybrid combination of both of these types. Also, the ECS 680 may be programmable, an integrated state machine, or a hybrid combination thereof. The ECS 680 may include one or more Arithmetic Logic Units (ALUs), Central Processing Units (CPUs), memories, limiters, conditioners, filters, format converters, or the like which are not shown to preserve clarity. In one form, the ECS 680 is of a programmable variety that executes algorithms and processes data in accordance with operating logic that is defined by programming instructions (such as software or firmware). Alternatively or additionally, operating logic for the ECS 680 may be at least partially defined by hardwired logic or other hardware.

[0057] In addition to the types of sensors described herein, any other suitable sensors and their associated parameters may be encompassed by the system and methods. Accordingly, the sensors may include any suitable device used to sense any relevant physical parameters including electrical, mechanical, and chemical parameters of system 610. As used herein, the term sensors may include any suitable hardware and / or software used to sense or estimate any engine system parameter and / or various combinations of such parameters either directly or indirectly.

[0058] With reference to FIG. 7, there is illustrated a flow diagram of a process 700 for detecting a fuel injector leak in engine 612 with an electronic control system (e.g., ECS 680 or another electronic control system), in operative communication with a fueling system (e.g., fueling system 614 or another fueling system). Process 700 may be implemented in and performed by one or more components of an electronic control system such as one or more electronic control units (e.g., ECU 682 and / or other electronic control units) and / or by other electronic control system components.

[0059] Process 700 begins at start operation 702 and proceeds to operation 704, which operates the engine 612 in a motoring condition. In the motoring condition, fuel is cut to fuel injectors 618, but air flow through cylinders 616 is maintained by continuing the nominal opening and closing operation of the intake and exhaust valves of each cylinder 618. The fuel can be stopped by controlling each individual injector 618, and / or by closing valve 664 in the fuel supply line.

[0060] Process 700 continues at operation 706 to sense one or more constituents in the air flow through exhaust system 624 connected to the engine 612 during the motoring condition. For example, hydrogen sensor 650 can be used to sense the air flow in order to directly detect hydrogen in the air flow in exhaust system 624. In another example, one or more of sensors 652, 654, 656 is used to indirectly detect hydrogen in the air flow in exhaust system 624 due to a cross-sensitivity to hydrogen in these types of sensors.

[0061] Process 700 continues at operation 708 to determine an injector leakage condition in response to the one or more constituents indicating hydrogen in the air flow. Once the injector leakage condition is determined, one or more further actions can be taken. For example, a warning light can be illuminated and / or a fault code can be generated by ECU 682. In another example, subsequent fueling commands to injectors 618 can be adjusted to account for the leakage, or the leaking injector(s) can be disabled.

[0062] In an embodiment, an amount of hydrogen in the air flow is determined and an injector leakage condition is determined in response to the determined amount exceeding a threshold. In an embodiment, engine 612 is cranked without fueling, or allowed to operate in the motoring condition for a predetermined amount of time, before executing the leak detection process in order to allowed any residual hydrogen in exhaust system 624 to be evacuated.

[0063] With reference to FIG. 8, there is illustrated a flow diagram of a process 800 for diagnosing a fuel injector or fuel injectors in engine 612 that are leaking using an electronic control system (e.g, ECS 680 or another electronic control system), in operative communication with a fueling system (e.g., fueling system 614 or another fueling system). Process 800 may be implemented in and performed by one or more components of an electronic control system such as one or more electronic control units (e.g, ECU 682 and / or other electronic control units) and / or by other electronic control system components.

[0064] Process 800 begins at start operation 802 and proceeds to operation 804 which operates the engine 612 in a motoring condition. Process 800 continues at operation 806 to sense a fuel injector leakage condition in response to one or more constituents in an air flow through exhaust system 624 connected to the engine 612 during the motoring condition. The fuel injector leakage condition can be determined, for example, by employing the process 700 discussed above.

[0065] Process 800 continues at operation 806 to identify a source of the fuel injector leakage during the motoring condition by selectively deactivating one or more cylinders 616 of the engine 612. In an embodiment, VVT system 660 is used to selectively deactivate one or more cylinders 616 to identify the cylinder or cylinders 616 having fuel injector leakage therein.

[0066] For example, if a leakage condition is determined based on the presence of hydrogen in exhaust system 624, but hydrogen is no longer present after air flow through a selected cylinder is stopped, then that cylinder 616 is diagnosed as having a fuel injector that leaks. In an embodiment, multiple cylinders 616 are simultaneously deactivated to identify a group of cylinders 616 associated with the injector leakage. Each cylinder 616 or subsets of cylinders 616 in the group identified as leaking are then deactivated to identify the particular injector or injectors 618 in the group contributing to the leakage condition.

[0067] In an embodiment, the one or more cylinders 616 are deactivated by VVT system 660 by closing the exhaust valve(s) of the deactivated cylinder during the motoring condition. In an embodiment, the one or more cylinders 616 are deactivated by VVT system 660 by closing the intake and exhaust valves of the deactivated cylinder during the motoring condition.

[0068] As shown by this detailed description, the present disclosure contemplates multiple and various aspects and embodiments, including, without limitation, the following aspects and example embodiments. In one aspect of the present disclosure, a method of operating a spark-ignited combustion engine that combusts hydrogen is provided. The method includes operating the engine with one or more operating parameters; monitoring one or more compartments of the engine for hydrogen during operation of the engine; determining a hydrogen amount in the one or more compartments exceeds a predetermined threshold; and adjusting the one or more operating parameters that control operation of the engine in response to the hydrogen amount exceeding the predetermined threshold to reduce the hydrogen in the one or more compartments.

[0069] In an embodiment, the monitoring the one or more compartments includes sensing one or more gaseous constituents in the one or more compartments with a physical sensor.

[0070] In a further embodiment, the physical sensor is at least one of a hydrogen sensor, a NOx sensor cross-sensitive to hydrogen, an oxygen sensor cross-sensitive to hydrogen, a carbon monoxide sensor cross-sensitive to hydrogen, and a carbon dioxide sensor cross-sensitive to hydrogen.

[0071] In an embodiment, the monitoring the one or more compartments for hydrogen includes predicting a hydrogen amount in the one or more compartments, the determining the hydrogen amount includes determining the predicted hydrogen amount exceeds the predetermined threshold, and adjusting the one or more operating parameters that control operation of the engine in response to the predicted hydrogen amount exceeding the predetermined threshold.

[0072] In an embodiment, the predetermined threshold is a predetermined flammability limit for hydrogen.

[0073] In an embodiment, the one or more compartments include an intake manifold and an exhaust manifold.

[0074] In a further embodiment, the adjusting the one or more operating parameters to reduce hydrogen in the intake manifold or exhaust manifold includes one or more of: adjusting an intake throttle position; adjusting an exhaust throttle position; adjusting a VGT position; adjusting an intake air flow through a charge air cooler bypass; adjusting an EGR valve position; adjusting an EGR flow through an EGR cooler bypass; adjusting variable valve actuation / timing settings; adjusting engine speed; adjusting ignition timing; and adjusting fuel injection timing.

[0075] In a further embodiment, the method includes determining the hydrogen amount in the one or more compartments exceeds the predetermined threshold after adjusting one of the one or more operating parameters; and / or adjusting one or more additional operating parameters.

[0076] In an embodiment, the one or more compartments include a valve cover and a crankcase.

[0077] In a further embodiment, the adjusting the one or more operating parameters to reduce hydrogen in the valve cover and / or the crankcase includes one or more of: activating a vacuum pump to pull gases out of the crankcase or valve cover; activating an air pump to push gases out of the crank case or valve cover; and / or forcing gases out of the crankcase or the valve cover through a breather system connecting the valve cover and the crankcase.

[0078] In another aspect of the present disclosure, a system includes an engine including a hydrogen fuel system and an ECU. The ECU is configured to perform operations to control the engine with one or more operating parameters; monitor one or more compartments connected to the engine for hydrogen during operation of the engine; determine a hydrogen amount in the one or more compartments exceeds a predetermined threshold; and adjust the one or more operating parameters that control operation of the engine in response to the hydrogen amount exceeding the predetermined threshold to reduce the hydrogen in the one or more compartments.

[0079] In an embodiment, the system includes a physical sensor associated with the one or more compartments configured to sense one or more gaseous constituents in the one or more compartments. The ECU is configured to perform operations to receive outputs from the physical sensor to monitor the one or more compartments for hydrogen.

[0080] In a further embodiment, the physical sensor is at least one of a hydrogen sensor, a NOx sensor cross-sensitive to hydrogen, an oxygen sensor cross-sensitive to hydrogen, a carbon monoxide sensor cross-sensitive to hydrogen, and a carbon dioxide sensor cross-sensitive to hydrogen.

[0081] In an embodiment, the ECU is configured to perform operations to monitor the one or more compartments by predicting a hydrogen amount in the one or more compartments; determine the hydrogen amount by determining the predicted hydrogen amount exceeds the predetermined threshold; and adjust the one or more operating parameters that control operation of the engine in response to the predicted hydrogen amount exceeding the predetermined threshold.

[0082] In an embodiment, the predetermined threshold is a predetermined flammability limit for hydrogen.

[0083] In an embodiment, the one or more compartments include an intake manifold and an exhaust manifold of the engine.

[0084] In a further embodiment, the engine includes one or more of an intake throttle, an exhaust throttle, a VGT, a charge air cooler and charge air cooler bypass, an EGR flow path with an EGR valve and an EGR bypass, a variable valve actuation / timing system, a spark plug, and a fuel injector. The ECU is configured to perform one or more of the following operations to adjust the one or more operating parameters to reduce hydrogen in the intake manifold and / or exhaust manifold: adjust an intake throttle position; adjust an exhaust throttle position; adjust a VGT position; adjust an intake air flow through a charge air cooler bypass; adjust an EGR valve position; adjust an EGR flow through an EGR cooler bypass; adjust variable valve actuation / timing settings; adjust engine speed; adjust ignition timing; and / or adjust fuel injection timing.

[0085] In a further embodiment, the ECU is configured to perform operations to: determine the hydrogen amount in the one or more compartments exceeds the predetermined threshold after one of the one or more operating parameters is adjusted; and adjust one or more additional operating parameters.

[0086] In an embodiment, the engine includes a breather system and the one or more compartments include a valve cover and a crankcase connected to the breather system.

[0087] In a further embodiment, the ECU is configured to perform one or more of the following operations to adjust the one or more operating parameters to reduce hydrogen in the valve cover or the crank case: activate a vacuum pump to pull gases out of the crankcase or valve cover; activate an air pump to push gases out of the crank case or valve cover; and / or force gases out of the crankcase or the valve cover through the breather system.

[0088] Another aspect of the present disclosure is a method of detecting a fuel injector leak in a spark-ignited combustion engine that combusts hydrogen that includes: operating the engine in a motoring condition; sensing one or more constituents in an air flow through an exhaust system connected to the engine during the motoring condition; and determining an injector leakage condition in response to the one or more constituents indicating hydrogen in the air flow through the exhaust.

[0089] In an embodiment, the sensing one or more constituents includes sensing the one or more constituents with at least one exhaust sensor. In an embodiment, the at least one exhaust sensor is a hydrogen sensor.

[0090] In an embodiment, the at least one exhaust sensor is a NOx sensor that is crosssensitive to hydrogen. In an embodiment, the at least one exhaust sensor is an oxygen sensor that is cross-sensitive to hydrogen.

[0091] In an embodiment, operating the engine in the motoring condition includes allowing air flow through the engine while not fueling the engine.

[0092] In an embodiment, the at least one sensor is located in the exhaust system upstream of a turbocharger. In an embodiment, the at least one sensor is located in the exhaust system downstream of an aftertreatment system.

[0093] In an embodiment, the method includes selectively isolating one or more cylinders of the engine to identify a source of the injector leakage condition. In a further embodiment, the selectively isolating the one or more cylinders includes deactivating exhaust valves of the one or more cylinders.

[0094] According to another aspect of the disclosure, a method of diagnosing a fuel injector leakage source in a spark -ignited combustion engine that combusts hydrogen includes: operating the engine in a motoring condition; sensing a fuel injector leakage condition in response to one or more constituents in an air flow through an exhaust system connected to the engine during the motoring condition; and identifying a source of the fuel injector leakage during the motoring condition by selectively deactivating one or more cylinders of the engine.

[0095] In an embodiment, identifying the source of the fuel injector leakage includes deactivating two or more of the cylinders of the engine.

[0096] According to another aspect of the disclosure, a fuel injector leakage detection system is provided. The system includes an internal combustion engine including a plurality of cylinders, each of the plurality of cylinders including a fuel injector configured to inject hydrogen fuel into the cylinder, an intake system configured to provide an air flow to the plurality of cylinders, an exhaust system for receiving an output from the plurality of cylinder, the exhaust system including at least one sensor, and an electronic control system. The electronic control system is configured to operate the engine in a motoring condition, receive outputs from the at least one sensor indicative of one or more constituents in the air flow fromthe plurality of cylinders to the exhaust system during the motoring condition, and determine an injector leakage condition of one or more of the fuel injectors in response to the one or more constituents indicating hydrogen in the air flow in the exhaust during the motoring condition.

[0097] In an embodiment, the at least one sensor is a hydrogen sensor. In an embodiment, the at least one sensor is a NOx sensor that is cross-sensitive to hydrogen. In an embodiment, the at least one sensor is an oxygen sensor that is cross-sensitive to hydrogen.

[0098] In an embodiment, the system includes a variable valve train system that is configured to deactivate selective ones of the plurality of cylinders, and the electronic control system is configured to selectively deactivate one or more of the plurality of cylinders to identify one or more of the fuel injectors causing the injector leakage condition.

[0099] In an embodiment, the exhaust system includes a turbocharger and an aftertreatment system downstream of the turbocharger, and the at least one sensor is located upstream of the turbocharger.

[0100] In an embodiment, the exhaust system includes an aftertreatment system downstream of the turbocharger, and the at least one sensor is located downstream of the aftertreatment system.

[0101] In an embodiment, the electronic control system is configured to determine an amount of hydrogen in the exhaust system based on the outputs from the at least one sensor in the exhaust system.

[0102] It shall be appreciated that terms such as “a non-transitory memory,” “a non- transitory memory medium,” and “a non-transitory memory device” refer to a number of types of devices and storage mediums which may be configured to store information, such as data or instructions, readable or executable by a processor or other components of a computer system and that such terms include and encompass a single or unitary device or medium storing such information, multiple devices or media across or among which respective portions of such information are stored, and multiple devices or media across or among which multiple copies of such information are stored.

[0103] It shall be appreciated that terms such as “determine,” “determined,” “determining” and the like when utilized in connection with a control method or process, an electronic control system or controller, electronic controls, or components or operations of the foregoing refer inclusively to a number of acts, configurations, devices, operations, and techniques including,without limitation, calculation or computation of a parameter or value, obtaining a parameter or value from a lookup table or using a lookup operation, receiving parameters or values from a datalink or network communication, receiving an electronic signal e.g., a voltage, frequency, current, or pulse-width modulation (PWM) signal) indicative of the parameter or value, receiving output of a sensor indicative of the parameter or value, receiving other outputs or inputs indicative of the parameter or value, reading the parameter or value from a memory location on a computer-readable medium, receiving the parameter or value as a run-time parameter, and / or by receiving a parameter or value by which the interpreted parameter can be calculated, and / or by referencing a default value that is interpreted to be the parameter value.

[0104] While example embodiments of the disclosure have been illustrated and described in detail in the drawings and foregoing description, the same is to be considered as illustrative and not restrictive in character, it being understood that only certain example embodiments have been shown and described and that all changes and modifications that come within the spirit of the claimed inventions are desired to be protected. It should be understood that while the use of words such as preferable, preferably, preferred or more preferred utilized in the description above indicates that the feature so described may be more desirable, it nonetheless may not be necessary and embodiments lacking the same may be contemplated as within the scope of the invention, the scope being defined by the claims that follow. In reading the claims, it is intended that when words such as “a,” “an,” “at least one,” or “at least one portion” are used there is no intention to limit the claim to only one item unless specifically stated to the contrary in the claim. When the language “at least a portion” and / or “a portion” is used the item can include a portion and / or the entire item unless specifically stated to the contrary.

Claims

WHAT IS CLAIMED IS:

1. A method of operating a spark-ignited combustion engine that combusts hydrogen, the method comprising: operating the engine with one or more operating parameters; monitoring one or more compartments of the engine for hydrogen during operation of the engine; determining a hydrogen amount in the one or more compartments exceeds a predetermined threshold; and adjusting the one or more operating parameters that control operation of the engine in response to the hydrogen amount exceeding the predetermined threshold to reduce the hydrogen in the one or more compartments.

2. The method of claim 1, wherein the monitoring the one or more compartments includes sensing one or more gaseous constituents in the one or more compartments with a physical sensor.

3. The method of claim 2, wherein the physical sensor is at least one of a hydrogen sensor, a NOx sensor cross-sensitive to hydrogen, an oxygen sensor cross-sensitive to hydrogen, a carbon monoxide sensor cross-sensitive to hydrogen, and a carbon dioxide sensor cross-sensitive to hydrogen.

4. The method of claim 1, wherein: the monitoring the one or more compartments for hydrogen includes predicting a hydrogen amount in the one or more compartments; the determining the hydrogen amount includes determining the predicted hydrogen amount exceeds the predetermined threshold; and adjusting the one or more operating parameters that control operation of the engine in response to the predicted hydrogen amount exceeding the predetermined threshold.

5. The method of claim 1, wherein the predetermined threshold is a predetermined flammability limit for hydrogen.

6. The method of claim 1, wherein the one or more compartments include an intake manifold and an exhaust manifold.

7. The method of claim 6, wherein the adjusting the one or more operating parameters to reduce hydrogen in the intake manifold or exhaust manifold includes one or more of: adjusting an intake throttle position; adjusting an exhaust throttle position; adjusting a VGT position; adjusting an intake air flow through a charge air cooler bypass; adjusting an EGR valve position; adjusting an EGR flow through an EGR cooler bypass; adjusting variable valve actuation / timing settings; adjusting engine speed; adjusting ignition timing; and adjusting fuel injection timing.

8. The method of claim 7, further comprising: determining the hydrogen amount in the one or more compartments exceeds the predetermined threshold after adjusting one of the one or more operating parameters; and / or adjusting one or more additional operating parameters.

9. The method of claim 1, wherein the one or more compartments include a valve cover and a crankcase.

10. The method of claim 9, wherein the adjusting the one or more operating parameters to reduce hydrogen in the valve cover and / or the crankcase includes one or more of: activating a vacuum pump to pull gases out of the crankcase or valve cover; activating an air pump to push gases out of the crank case or valve cover; and / orforcing gases out of the crankcase or the valve cover through a breather system connecting the valve cover and the crankcase.

11. A system comprising: an engine including a hydrogen fuel system and an electronic control unit (ECU) configured to perform operations to: control the engine with one or more operating parameters; monitor one or more compartments connected to the engine for hydrogen during operation of the engine; determine a hydrogen amount in the one or more compartments exceeds a predetermined threshold; and adjust the one or more operating parameters that control operation of the engine in response to the hydrogen amount exceeding the predetermined threshold to reduce the hydrogen in the one or more compartments.

12. The system of claim 11, further comprising a physical sensor associated with the one or more compartments configured to sense one or more gaseous constituents in the one or more compartments, the ECU configured to perform operations to receive outputs from the physical sensor to monitor the one or more compartments for hydrogen.

13. The system of claim 12, wherein the physical sensor is at least one of a hydrogen sensor, a NOx sensor cross-sensitive to hydrogen, an oxygen sensor cross-sensitive to hydrogen, a carbon monoxide sensor cross-sensitive to hydrogen, and a carbon dioxide sensor cross-sensitive to hydrogen.

14. The system of claim 11, wherein the ECU is configured to perform operations to: monitor the one or more compartments by predicting a hydrogen amount in the one or more compartments; determine the hydrogen amount by determining the predicted hydrogen amount exceeds the predetermined threshold; andadjust the one or more operating parameters that control operation of the engine in response to the predicted hydrogen amount exceeding the predetermined threshold.

15. The system of claim 11, wherein the predetermined threshold is a predetermined flammability limit for hydrogen.

16. The system of claim 11, wherein the one or more compartments include an intake manifold and an exhaust manifold of the engine.

17. The system of claim 16, wherein the engine includes one or more of an intake throttle, an exhaust throttle, a VGT, a charge air cooler and charge air cooler bypass, an EGR flow path with an EGR valve and an EGR bypass, a variable valve actuation / timing system, a spark plug, and a fuel injector, and the ECU is configured to perform one or more of the following operations to adjust the one or more operating parameters to reduce hydrogen in the intake manifold and / or exhaust manifold: adjust an intake throttle position; adjust an exhaust throttle position; adjust a VGT position; adjust an intake air flow through a charge air cooler bypass; adjust an EGR valve position; adjust an EGR flow through an EGR cooler bypass; adjust variable valve actuation / timing settings; adjust engine speed; adjust ignition timing; and / or adjust fuel injection timing.

18. The method of claim 17, wherein the ECU is configured to perform operations to: determine the hydrogen amount in the one or more compartments exceeds the predetermined threshold after one of the one or more operating parameters is adjusted; and adjust one or more additional operating parameters.

19. The system of claim 1 1, wherein the engine includes a breather system and the one or more compartments include a valve cover and a crankcase connected to the breather system.

20. The system of claim 19, wherein the ECU is configured to perform one or more of the following operations to adjust the one or more operating parameters to reduce hydrogen in the valve cover or the crank case: activate a vacuum pump to pull gases out of the crankcase or valve cover; activate an air pump to push gases out of the crank case or valve cover; and / or force gases out of the crankcase or the valve cover through the breather system.

21. A method of detecting a fuel injector leak in a spark-ignited combustion engine that combusts hydrogen, the method comprising: operating the engine in a motoring condition; sensing one or more constituents in an air flow through an exhaust system connected to the engine during the motoring condition; and determining an injector leakage condition in response to the one or more constituents indicating hydrogen in the air flow through the exhaust.

22. The method of claim 21, wherein the sensing one or more constituents includes sensing the one or more constituents with at least one exhaust sensor.

23. The method of claim 21, wherein the at least one exhaust sensor is a hydrogen sensor.

24. The method of claim 21, wherein the at least one exhaust sensor is a NOx sensor that is cross-sensitive to hydrogen.

25. The method of claim 21, wherein the at least one exhaust sensor is an oxygen sensor that is cross-sensitive to hydrogen.

26. The method of claim 21, wherein operating the engine in the motoring condition includes allowing air flow through the engine while not fueling the engine.

27. The method of claim 21, wherein the at least one sensor is located in the exhaust system upstream of a turbocharger.

28. The method of claim 21, wherein the at least one sensor is located in the exhaust system downstream of an aftertreatment system.

29. The method of claim 21, further comprising selectively isolating one or more cylinders of the engine to identify a source of the injector leakage condition.

30. The method of claim 29, wherein the selectively isolating the one or more cylinders includes deactivating exhaust valves of the one or more cylinders.

31. A method of diagnosing a fuel injector leakage source in a spark-ignited combustion engine that combusts hydrogen, the method comprising: operating the engine in a motoring condition; sensing a fuel injector leakage condition in response to one or more constituents in an air flow through an exhaust system connected to the engine during the motoring condition; and identifying a source of the fuel injector leakage during the motoring condition by selectively deactivating one or more cylinders of the engine.

32. The method of claim 31, wherein identifying the source of the fuel injector leakage includes deactivating two or more of the cylinders of the engine.

33. A fuel injector leakage detection system, the system comprising: an internal combustion engine including a plurality of cylinders, each of the plurality of cylinders including a fuel injector configured to inject hydrogen fuel into the cylinder; an intake system configured to provide an air flow to the plurality of cylinders; an exhaust system for receiving an output from the plurality of cylinder, the exhaust system including at least one sensor; and an electronic control system configured to:operate the engine in a motoring condition; receive outputs from the at least one sensor indicative of one or more constituents in the air flow from the plurality of cylinders to the exhaust system during the motoring condition; and determine an injector leakage condition of one or more of the fuel injectors in response to the one or more constituents indicating hydrogen in the air flow in the exhaust during the motoring condition.

34. The system of claim 33, wherein the at least one sensor is a hydrogen sensor.

35. The system of claim 33, wherein the at least one sensor is a NOx sensor that is crosssensitive to hydrogen.

36. The system of claim 33, wherein the at least one sensor is an oxygen sensor that is crosssensitive to hydrogen.

37. The system of claim 33, further comprising a variable valve train system that is configured to deactivate selective ones of the plurality of cylinders, and wherein the electronic control system is configured to selectively deactivate one or more of the plurality of cylinders to identify one or more of the fuel injectors causing the injector leakage condition.

38. The system of claim 33, wherein the exhaust system includes a turbocharger and an aftertreatment system downstream of the turbocharger, and the at least one sensor is located upstream of the turbocharger.

39. The system of claim 33, wherein the exhaust system includes an aftertreatment system downstream of the turbocharger, and the at least one sensor is located downstream of the aftertreatment system.

40. The system of claim 33, wherein the electronic control system is configured to determine an amount of hydrogen in the exhaust system based on the outputs from the at least one sensor in the exhaust system.

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