System and method for detecting fuel system failures and leaks in hydrogen combustion engines

Abstract

Fuel system failure and / or leak detection is disclosed for a spark-ignited combustion engine that combusts hydrogen fuel. Pressure measurements of the hydrogen fueling system are taken to determine a rail pressure error based on a differential between the commanded rail pressure and the sensed rail pressure. A hydrogen fuel system failure or leak condition is detected in response to the rail pressure error falling outside an allowable rail pressure governor error that varies based on engine speed.

Description

SYSTEM AND METHOD FOR DETECTING FUEL SYSTEM FAILURES AND LEAKS INHYDROGEN COMBUSTION ENGINESCROSS-REFERENCE TO RELATED APPLICATION

[0001] The present application claims priority to, and the benefit of the filing date of, India Provisional Application Ser. No. 202441040482 filed on May 24, 2024, which is incorporated herein by reference.TECHNICAL FIELD

[0002] The present application relates to apparatuses, methods, systems, and techniques for detecting fuel system failures and leaks for internal combustion engines that combust hydrogen fuel.BACKGROUND

[0003] Internal combustion engines may experience fuel system failures and / or leaks during operation, which affects combustion of the air-fuel mixture and may result in fuel collecting in areas of the engine not intended to receive or store fuel. Internal combustion engines that combust hydrogen require the hydrogen fuel to be compressed and stored at high pressures. Since hydrogen gas can ignite at low ignition energy and has a wide flammability range, an occurrence of hydrogen fuel leakage and / or a local accumulation of hydrogen needs to be detected so mitigation measures can be implemented.

[0004] Various attempts have been made to detect and / or diagnose fuel system failures and / or leaks. Existing approaches suffer from a number of disadvantages and shortcomings, including inability or insufficiency in detecting and / or identifying fuel leakage, inability or insufficiency in detecting and / or identifying fuel system failures, and / or increased costs due to implementing additional sensors for hydrogen leak detection. There remains a significant need for the unique apparatuses, methods, systems, and techniques of the present disclosure.DISCLOSURE OF EXAMPLE EMBODIMENTS

[0005] 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

[0006] Some embodiments include unique apparatuses for fuel system failure detection and / or fuel leak detection for hydrogen combustion engines. Some embodiments include unique methods for fuel system failure detection and / or fuel leak detection for hydrogen combustion engines. Some embodiments include unique systems for fuel system failure detection and / or fuel leak detection for hydrogen combustion engines. Some embodiments include unique techniques for fuel system failure detection and / or fuel leak detection 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 prime mover system.

[0008] FIG. 2 is a schematic diagram illustrating certain aspects of a fuel system failure and fuel leak detection control system.

[0009] FIGs. 3A-3C are graphical illustrations showing possible rail pressure governor errors.

[0010] FIG. 4 is a flow diagram illustrating certain aspects of an embodiment of a fuel system failure and fuel leak detection process.

[0011] FIG. 5 is a flow diagram illustrating certain aspects of an embodiment of a fuel system failure and fuel leak detection process.DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS

[0012] With reference to FIG. 1, there is illustrated an example powertrain system 10 (also referred to herein as system 10) that includes a prime mover 12, such as a spark-ignited combustion engine that combusts hydrogen fuel, and a fueling system 14. Fueling system 14 is adapted and configured to supply gaseous hydrogen to prime mover 12 for combustion in one or more combustion chambers 16. In some embodiments, fueling system 14 may be additionally adapted and configured to supply one or more other fuels for combustion to prime mover 12 in combination with gaseous hydrogen. For example, prime mover 12 may run solely on hydrogen, on diesel and hydrogen, on natural gas and hydrogen, on propane and hydrogen, etc.

[0013] In an embodiment, system 10 includes an electronic control system (ECS) 80 with at least one electronic control unit (ECU) 82 configured to operate prime mover 12 with one or more operating parameters. The ECU 82 monitors fueling system 14 of prime mover 12 for hydrogen fuel leakage and / or failure of fueling system 14 during operation of prime mover 12. The ECU 82 determines a hydrogen fuel leak condition and / or a failure condition for fueling system 14 is present for fueling system 14 in response to a differential between a rail pressure error and a rail pressure governor error, as discussed further below. In an embodiment, ECU 82 may adjust one or more operating parameters that control operation of prime mover 12 in response to the hydrogen fuel leak condition to reduce hydrogen fuel leakage and or to maintain hydrogen levels around fueling system 14 below flammability limits.

[0014] In the illustrated embodiment, prime mover 12 is an internal combustion engine that includes 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 18. Cylinders 16 and fuel injectors 18 may be provided in any suitable number based on the number of cylinders 16. For example, although six cylinders 16 and six fuel injectors 18 are illustrated in FIG. 1, any number of cylinders 16, each with one or more fuel injectors 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 a vehicle, a genset, other power-load system.

[0015] Fuel injectors 18 are in fluid communication with respective combustion chambers of cylinders 16 of the prime mover 12 and are structured to inject gaseous fuel. Fuel injectors 18may be configured and provided as direct fuel injectors configured to inject fuel directly into respective combustion chambers of cylinders 16, or as port injectors that inject fuel directly into ports of intake manifold 20 leading to respective combustion chambers of cylinders 16. In other embodiments injectors 18 inject fuel into a manifold or other fuel distribution means. Each cylinder 16 may also include a spark plug (not shown) for spark ignition of the air-fuel mixture in the combustion chambers of cylinders 16. It should be appreciated that engine 12 may include cylinders 16 arranged and configured in a variety of manners, including in-line arrangements, V- shaped arrangements, multiple cylinder banks, vertical orientations, horizontal orientations, etc.

[0016] Fueling system 14 includes at least one fuel rail 40 that is connected to fuel injectors 18. Fuel rail 40 includes at least one rail pressure sensor 52 to provide signals indicative of the pressure condition in fuel rail 40 and / or at least one rail temperature sensor 54 to provide signals indicative of a temperature in fuel rail 40. Fuel rail 40 further includes a rail inlet 42 that receives hydrogen fuel from pressure regulator 60. Pressure regulator 60 includes a regulator inlet 62 that receives fuel from a fuel tank regulator 70. Fuel tank regulator 70 is connected to a hydrogen fuel source, such as at least one hydrogen fuel tank 72. Although only one fuel tank 72 is shown in the illustrated embodiment, multiple fuel tanks are also contemplated.

[0017] Pressure regulator 60 also includes a pressure sensor 64 to provide signals indicative of the pressure condition in pressure regulator 60. Pressure regulator 60 can be controlled by pulse width modulation (PWM) valves or other suitable devices in order to maintain a fuel supply in fuel rail 40 at a desired supply pressure for injectors 18. Pressure regulator 60 may also include a shut-off valve 66 that prevents fuel flow into pressure regulator 60 when prime mover 12 is shut down.

[0018] In another embodiment, prime mover 12 may include multiple common fuel rails 40 dedicated to different portions of the fuel injectors 18. One or more pressure regulators 60 and / or fuel rails 40 are also contemplated, such as may be provided for a prime mover 12 that is an engine with multiple cylinder banks, and / or for a V6 engine, a V8 engine, a V10 engine, a VI 2 engine, a VI 6 engine, etc.

[0019] Electronically controllable pressure regulator 60 can be configured to control supply of gaseous fuel from tank pressure regulator 70 and to fuel rail 40. Fueling system 14 can be controlled to be isolated or shut-off during operation of prime mover 12 so that fuel flow throughone or more of the injectors 18 is cut-off to shut down prime mover 12 or reduced to derate prime mover 12 in response to detection of hydrogen fuel leakage or a failure of a hydrogen fuel system 14.

[0020] System 10 includes one or more sensors configured to sense or detect one or more characteristics associated with operation of system 10, prime mover 12, and / or fueling system 14. 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 pressure sensors 52, 64 in communication with one or more components of fueling system 14 to provide output signals indicate of pressure conditions of the one or more components and one or more engine sensors 22 to provide output signals indicative of engine speed.

[0021] System 10 further includes ECS 80 in communication with prime mover 12 and fueling system 14. ECS is configured to control one or more aspects of prime mover 12 and / or fueling system 14, including controlling the injection of fuel into prime mover 12. 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 prime mover 12 as desired for ignition at a desired ignition timing. ECS 80 includes 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.

[0022] ECS 80 may be further structured to control other operating parameters of prime mover 12, which may include aspects of prime mover 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 prime mover 12 may include, but are not limited to, fuel injectors 18 and / or a speed of prime mover 12.

[0023] In at least one embodiment, system 10 may include one or more sensors in communication with the ECS 80 and structured to determine characteristics of prime mover 12 and fueling system 14 and detect a hydrogen fuel leak condition and / or a failure of fueling system 14 in response to the characteristics. In at least one embodiment of system 10, one or more sensors 22, 52, 54, 64 in communication with the ECS 80 represents a virtual sensor thatdetermines a value based on an algorithm for predicting or determining the value based on one or more other sensor inputs and / or operating conditions.

[0024] As will be appreciated by the description that follows, the techniques described herein relating to fuel leak and / or fuel system failure detection and / or control of operating parameters of prime mover 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, filters, 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.

[0025] 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.

[0026] With reference to FIG. 2, a control system 200, such as an embodiment of ECS 80, is illustrated. Control system 200 includes pressure regulator 60 connected to ECU 82 to receive a rail pressure command for fuel rail 40 from ECU 82. Pressure regulator 60 is configured to provide an output 202 of fuel that corresponds to the commanded rail pressure to fuel rail 40. Control system 200 includes a feedback loop 204 that receives an actual pressure value for the fuel in fuel rail 40, such as by sensing the pressure with a pressure sensor, at the output side of pressure regulator 60. The actual rail pressure associated with fuel rail 40 is provided to summation operator 206 by feedback loop 204 along with an input 208 that includes thecommanded rail pressure. The commanded rail pressure of input 208 may be determined from, for example, a fueling table or algorithm that provides the rail pressure command and other fueling parameters for fueling prime mover 12, such as injection timing, injection duration, injection amount, spark timing, etc.

[0027] Summation operator 206 determines a rail pressure error based on a difference between the commanded rail pressure provided by input 208 and the actual rail pressure provided by feedback loop 204. ECU 82 is also configured to determine a rail pressure governor error 210 based on a speed of prime mover 12. In an embodiment, the rail pressure governor error 210 is selected from look-up tables. Other means for determining the rail pressure governor error are also contemplated, such as operating maps, algorithms, etc. The rail pressure governor error look-up tables provide an indication of allowable or acceptable positive and negative rail pressure governor error values that vary based on engine speed.

[0028] As shown in FIGs. 3A-3C and discussed further below, the leakage or failure of the hydrogen fueling system 14 is determined present in response to a differential between the rail pressure error and the rail pressure governor error by more than a threshold amount. For example, as shown in FIG. 3A, a positive governor deviation error 300 is indicated by the commanded ratio pressure 302 being greater than the actual rail pressure 304 by a positive differential 306. This positive differential 306 is compared to an allowable positive rail pressure governor error determined from the look-up table (or other means) and a fault condition is indicated when differential 306 is greater than and therefor falling outside of the positive allowable rail pressure governor error at the given engine speed.

[0029] In FIG. 3B, a negative governor deviation error 310 is indicated by the commanded ratio pressure 312 being less than the actual rail pressure 314 by a negative differential 316. This negative differential 316 is compared to an allowable negative rail pressure governor error determined from the look-up table (or other means) and a fault condition is indicated when the negative differential 316 is less than and therefore falls outside of the negative allowable rail pressure governor error at the given engine speed. In FIG. 3C, normal operating conditions are shown in which the positive differential 306 and the negative differential 316 are less than the positive allowable rail pressure governor error and negative allowable rail pressure governor error.

[0030] With reference to FIG. 4, there is illustrated a flow diagram of a positive governor error process 400 for detecting and / or reacting to a leak or failure condition in fueling system 14 of prime mover 12 with an electronic control system e.g., ECS 80, control system 200, or another electronic control system), in operative communication with a fueling system (e.g., fueling system 14 or another fueling system). Process 400 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.

[0031] Process 400 begins at start 402, which operates prime mover 12 using combustion of hydrogen fuel from fueling system 14. In an embodiment, prime mover 12 is a spark-ignited combustion engine and fueling system 14 includes fuel rail 40 connected to the plurality of fuel injectors 18 and pressure regulator 60 to provide fuel to fuel rail 40 at the commanded pressure.

[0032] Process 400 continues at first input step 404 to receive values for a commanded rail pressure for fuel rail 40 and an actual or sensed rail pressure at the outlet side of pressure regulator 60. In parallel, process 400 includes a second input step 406 to receive a value for engine speed that corresponds with the actual rail pressure value that is received at input step 404.

[0033] Process 400 then continues at operation 408 to calculate the rail pressure error by determining a differential between the commanded rail pressure and the actual rail pressure. This differential from operation 408 is produced at output step 410 as the rail pressure error. Since the commanded rail pressure is greater than the actual rail pressure, the rail pressure error is positive. In parallel, process 400 includes operation 412 to look up the allowable positive rail pressure governor error from look-up table 414. Look-up table 414 includes, for example, a plurality of engine speeds and an allowable positive rail pressure governor error for each of the plurality of engine speeds The look-up result is produced at output step 416 as an allowable positive rail pressure governor error for the engine speed received at input step 406.

[0034] Process 400 continues at conditional 418 to determine if the rail pressure error from output step 410 falls outside the allowable positive rail pressure governor error from output step 416. For example, since the rail pressure error and allowable rail pressure governor error arepositive, the rail pressure error falls outside the allowable rail pressure governor error if the rail pressure error is greater than the allowable rail pressure governor error.

[0035] If conditional 418 is NO, process 400 returns to start 402. If conditional 418 is YES, a timer 420 is started. Process 400 then continues at conditional 422 to determine if the rail pressure error falls outside the allowable positive rail pressure governor error for a calibratable time threshold. This ensures temporal spikes or short-term pressure fluctuations are not flagged as fault conditions. If conditional 422 is NO, process 400 continues at operation 424 to output a diagnostic pass condition and / or clear any error condition or message, and then return to start 402.

[0036] If conditional 422 is YES, process 400 continues at operation 426 to set a fault or error detection flag for the rail pressure governor error indicating a leak or failure condition of fueling system 14. Process 400 then continues at operation 428 to take one or more actions in response to the error or fault detection flag set at operation 426. For example, an alert may be output to the driver and / or other party. Alternatively or additionally, a derate mode of operation may be initiated to reduce the fuel usage of and demand for fuel by prime mover 12. Alternatively or additionally, a shutoff valve, such as valve 64, in fueling system 14 may be closed to prevent further fueling of prime mover 12 with hydrogen fuel. Process 400 can then conclude at stop 430.

[0037] With reference to FIG. 5, there is illustrated a flow diagram of a negative governor error process 500. Process 500 is similar to process 400 except as otherwise noted below. Process 500 begins at start 502 and continues at first input step 504 to receive values for a commanded rail pressure for fuel rail 40 and an actual or sensed rail pressure at the outlet side of pressure regulator 60. In parallel, process 500 includes a second input step 506 to receive a value for engine speed that corresponds with the actual rail pressure value.

[0038] Process 500 then continues at operation 508 to calculate the rail pressure error by determining a differential between the commanded rail pressure and the actual rail pressure. This differential from operation 508 is produced at output step 510 as the rail pressure error. In this embodiment, since the actual rail pressure is greater than the commanded rail pressure, the rail pressure error is negative.

[0039] In parallel, process 500 includes operation 512 to look up the allowable negative rail pressure governor error from look-up table 514. Look-up table 514 includes, for example, a plurality of engine speeds and an allowable negative rail pressure governor error for each of the plurality of engine speeds The look-up result is produced at output step 516 as an allowable negative rail pressure governor error at the engine speed received at input step 506.

[0040] Process 500 continues at conditional 518 to determine if the rail pressure error from output step 510 falls outside the allowable negative rail pressure governor error from output step 516. For example, since the rail pressure error and allowable rail pressure governor error are negative, the rail pressure error falls outside the allowable negative rail pressure governor error if the negative rail pressure error is less than negative the allowable rail pressure governor error. If conditional 518 is NO, process 500 returns to start 502. If conditional 518 is YES, process 500 continues at conditional 519 to determine if prime mover 12 is in an overrun condition, such as continuing to run when the ignition is off. If conditional 519 is YES, process 500 returns to continue to receive outputs of the rail pressure error and allowable negative rail pressure governor error until the overrun condition is terminated.

[0041] If conditional 519 is NO, a timer 520 is started. Process 500 then continues at conditional 522 to determine if the rail pressure error falls outside the allowable negative rail pressure governor error for a calibratable time threshold to ensure temporal spikes or short-term pressure fluctuations are not flagged as fault conditions. If conditional 522 is NO, process 500 continues at operation 524 to output a diagnostic pass condition and / or clear any error condition or message, and then return to start 502.

[0042] If conditional 522 is YES, process 500 continues at operation 526 to set a fault or error detection flag indicating a leak or failure condition of fueling system 14. Process 500 then continues at operation 528 to take one or more actions in response to the error or fault detection. For example, an alert may be output to the driver and / or other party. Alternatively or additionally, a derate mode of operation may be initiated to reduce the fuel usage of and demand for fuel by prime mover 12. Alternatively or additionally, a shutoff valve in fueling system 14 may be closed to prevent further fueling of prime mover 12 with hydrogen fuel. Process 500 can then conclude at end 530.

[0043] As shown by this detailed description, the present disclosure contemplates multiple and various embodiments, including, without limitation, the following example embodiments. In an embodiment, a method for detecting a leakage or failure of a hydrogen fueling system is provided. The method includes operating a spark-ignited combustion engine with hydrogen fuel provided by the hydrogen fueling system in which the hydrogen fueling system includes a pressure regulator that received hydrogen fuel from a fuel source and a fuel rail and the fuel rail connected to the pressure regulator and a plurality of fuel injectors; determining a rail pressure error based on a difference between a commanded rail pressure associated with the fuel rail and an actual pressure associated with the fuel rail; determining an allowable rail pressure governor error based on a speed of the spark-ignited combustion engine; and determining the leakage or failure of the hydrogen fueling system is present in response to the rail pressure error falling outside the allowable rail pressure governor error.

[0044] In an embodiment, the method includes adjusting the operation of the spark-ignited combustion engine in response to the leakage or failure of the hydrogen fueling system being determined.

[0045] In a further embodiment, adjusting the operation of the spark-ignited combustion engine includes outputting an alert; initiating engine protection measures; and / or isolating the fueling system from the fuel source.

[0046] In an embodiment, in response to the rail pressure error being positive, the method includes starting a timer and determining the leakage or failure of the hydrogen fueling system is present only if the rail pressure error falling outside the allowable rail pressure governor error over a calibratable time threshold.

[0047] In a further embodiment, if the rail pressure error does not fall outside the allowable rail pressure governor error for the calibratable time threshold, the method includes determining the leakage or failure of the hydrogen fueling system is not present.

[0048] In an embodiment, the allowable rail pressure governor error is determined from a look-up table that includes a plurality of allowable rail pressure governor error values each linked to a corresponding one of a plurality of engine speed values.

[0049] In an embodiment, in response to the rail pressure error being negative, the method includes determining the spark-ignited combustion engine is not in an overrun condition; starting a timer; and determining the leakage or failure of the hydrogen fueling system is present only if the rail pressure error falls outside the allowable rail pressure governor error over a calibratable time threshold.

[0050] In a further embodiment, in response to determining the spark-ignited combustion engine is in the overrun condition, the method includes continuing to determine if the rail pressure error falls outside the allowable rail pressure governor error while spark-ignited combustion engine is in the overrun condition.

[0051] According to another aspect of the disclosure, a system for detecting a leakage or failure of a hydrogen fueling system is provided. The system includes a spark-ignited combustion engine connected to the hydrogen fueling system. The hydrogen fueling system includes a pressure regulator connected to a fuel source to receive hydrogen fuel. The fueling system further includes at least one fuel rail connected to the pressure regulator and a plurality of fuel injectors connected to the at least one fuel rail. The spark-ignited combustion engine further includes an electronic control unit (ECU) configured to perform operations to: operate the spark- ignited combustion engine with hydrogen fuel from the hydrogen fuel source using the hydrogen fueling system; determine a rail pressure error based on a difference between a commanded rail pressure associated with the fuel rail and an actual pressure associated with the fuel rail; determine an allowable rail pressure governor error based on a speed of the spark-ignited combustion engine; and determine the leakage or failure of the hydrogen fueling system is present in response to the rail pressure error falls outside the allowable rail pressure governor error.

[0052] In an embodiment, the pressure regulator is connected to the ECU, and the ECU is configured to perform operations to regulate a flow of the hydrogen fuel from the hydrogen fuel source to the fuel rail through the pressure regulator.

[0053] In a further embodiment, the spark-ignited combustion engine includes a plurality of pressure sensors connected to the ECU. The plurality of pressure sensors includes a first pressure sensor for sensing a pressure condition of the pressure regulator and a second pressure sensor for sensing a pressure condition of the fuel rail.

[0054] In an embodiment, the ECU is configured to adjust the operation of the spark-ignited combustion engine in response to the leakage or failure of the hydrogen fueling system being determined.

[0055] In an embodiment, the ECU is configured to start a timer and determine the leakage or failure of the hydrogen fueling system is present only if the rail pressure error falls outside the allowable rail pressure governor error persists for a calibratable time threshold.

[0056] In a further embodiment, the ECU is configured to determine the rail pressure error is positive in response to the commanded rail pressure being greater than the actual pressure associated with the fuel rail and determine the rail pressure error is negative in response to the commanded rail pressure being less than the actual pressure associated with the fuel rail.

[0057] In a further embodiment, in response to the rail pressure error being negative, the ECU is configured to determine the spark -ignited combustion engine is not in an overrun condition before starting the timer.

[0058] In a further embodiment, the positive rail pressure error is indicative of a fuel line leakage, wear of the pressure regulator, at least one needle of the plurality of fuel injectors being stuck open, wear of at least one needle seat of the plurality of fuel injectors, a clogged filter within at least one of the plurality of fuel injectors, and / or a low fuel supply pressure upstream of the fuel regulator. The negative rail pressure error is indicative of the pressure regulator being stuck open and / or a high fuel supply pressure upstream of the pressure regulator.

[0059] In an embodiment, the hydrogen fueling system includes a hydrogen fuel storage tank for storing hydrogen fuel, a tank pressure regulator connected between the hydrogen fuel storage tank and the pressure regulator, and the ECU is configured to detect the leakage or failure of the hydrogen fueling system downstream of the tank pressure regulator.

[0060] According to another aspect of the disclosure, an apparatus for detecting a leakage or failure of a hydrogen fueling system for a spark-ignited combustion engine is provided. The apparatus includes a non-transitory memory medium configured to store instructions executable by a processor to perform the acts of a non-transitory memory medium configured to store instructions executable by a processor to perform the acts of operate the spark-ignited combustion engine with hydrogen fuel using the hydrogen fueling system; determine a railpressure error based on a difference between a commanded rail pressure associated with a fuel rail of the hydrogen fueling system and an actual pressure associated with the fuel rail; determine a rail pressure governor error based on a speed of the spark-ignited combustion engine; and determine the leakage or failure of the hydrogen fueling system is present in response the rail pressure error falling outside the allowable rail pressure governor error.

[0061] In an embodiment, the non-transitory memory medium stores instructions executable by the processor to perform the act of determine the leakage or failure of the hydrogen fueling system is present only if the rail pressure error falling outside the allowable the rail pressure governor error over a calibratable time threshold.

[0062] In an embodiment, the non-transitory memory medium stores instructions executable by the processor to perform the act of adjust the operation of the spark-ignited combustion engine in response to the leakage or failure of the hydrogen fueling system hydrogen fuel leak condition.

[0063] 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.

[0064] 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 inputsindicative 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.

[0065] 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 detecting a leakage or failure of a hydrogen fueling system, the method comprising: operating a spark-ignited combustion engine with hydrogen fuel provided by the hydrogen fueling system, the hydrogen fueling system including a pressure regulator that received hydrogen fuel from a fuel source and a fuel rail, the fuel rail connected to the pressure regulator and a plurality of fuel injectors; determining a rail pressure error based on a difference between a commanded rail pressure associated with the fuel rail and an actual pressure associated with the fuel rail; determining an allowable rail pressure governor error based on a speed of the spark- ignited combustion engine; and determining the leakage or failure of the hydrogen fueling system is present in response to the rail pressure error falling outside the allowable rail pressure governor error.

2. The method according to claim 1, comprising adjusting the operation of the spark-ignited combustion engine in response to the leakage or failure of the hydrogen fueling system being determined.

3. The method according to claim 2, wherein adjusting the operation of the park-ignited combustion engine includes: outputting an alert; initiating engine protection measures; and / or isolating the fueling system from the fuel source.

4. The method according to claim 1, wherein, in response to the rail pressure error being positive, the method includes: starting a timer; and determining the leakage or failure of the hydrogen fueling system is present only if the rail pressure error falling outside the allowable rail pressure governor error over a calibratable time threshold.

5. The method according to claim 4, wherein, if the rail pressure error does not fall outside the allowable rail pressure governor error for the calibratable time threshold, determining the leakage or failure of the hydrogen fueling system is not present.

6. The method according to claim 1, wherein the allowable rail pressure governor error is determined from a look-up table that includes a plurality of allowable rail pressure governor error values each linked to a corresponding one of a plurality of engine speed values.

7. The method according to claim 1, wherein, in response to the rail pressure error being negative, the method includes: determining the spark-ignited combustion engine is not in an overrun condition; starting a timer; and determining the leakage or failure of the hydrogen fueling system is present only if the rail pressure error falls outside the allowable rail pressure governor error over a calibratable time threshold.

8. The method according to claim 7, wherein, in response to determining the spark-ignited combustion engine is in the overrun condition, the method includes continuing to determine if the rail pressure error falls outside the allowable rail pressure governor error while spark-ignited combustion engine is in the overrun condition.

9. A system for detecting a leakage or failure of a hydrogen fueling system, the system comprising: a spark-ignited combustion engine connected to the hydrogen fueling system, the hydrogen fueling system including a pressure regulator connected to a fuel source to receive hydrogen fuel, the fueling system including at least one fuel rail connected to the pressure regulator and a plurality of fuel injectors connected to the at least one fuel rail, the spark-ignited combustion engine including an electronic control unit (ECU) configured to perform operations to:operate the spark-ignited combustion engine with hydrogen fuel from the hydrogen fuel source using the hydrogen fueling system; determine a rail pressure error based on a difference between a commanded rail pressure associated with the fuel rail and an actual pressure associated with the fuel rail; determine an allowable rail pressure governor error based on a speed of the spark- ignited combustion engine; and determine the leakage or failure of the hydrogen fueling system is present in response to the rail pressure error falls outside the allowable rail pressure governor error.

10. The system according to claim 9, wherein the pressure regulator is connected to the ECU, and the ECU is configured to perform operations to regulate a flow of the hydrogen fuel from the hydrogen fuel source to the fuel rail through the pressure regulator.

11. The system according to claim 10, wherein the spark-ignited combustion engine comprises: a plurality of pressure sensors connected to the ECU, the plurality of pressure sensors including a first pressure sensor for sensing a pressure condition of the pressure regulator and a second pressure sensor for sensing a pressure condition of the fuel rail.

12. The system according to claim 9, wherein the ECU is configured to adjust the operation of the spark-ignited combustion engine in response to the leakage or failure of the hydrogen fueling system being determined.

13. The system according to claim 9, wherein the ECU is configured to: start a timer; and determine the leakage or failure of the hydrogen fueling system is present only if the rail pressure error falls outside the allowable rail pressure governor error persists for a calibratable time threshold.

14. The system according to claim 13, wherein the ECU is configured to:determine the rail pressure error is positive in response to the commanded rail pressure being greater than the actual pressure associated with the fuel rail; and determine the rail pressure error is negative in response to the commanded rail pressure being less than the actual pressure associated with the fuel rail.

15. The system according to claim 14, wherein, in response to the rail pressure error being negative, the ECU is configured to determine the spark-ignited combustion engine is not in an overrun condition before starting the timer.

16. The system according to claim 14, wherein: the positive rail pressure error is indicative of a fuel line leakage, wear of the pressure regulator, at least one needle of the plurality of fuel injectors being stuck open, wear of at least one needle seat of the plurality of fuel injectors, a clogged filter within at least one of the plurality of fuel injectors, and / or a low fuel supply pressure upstream of the fuel regulator; and the negative rail pressure error is indicative of the pressure regulator being stuck open and / or a high fuel supply pressure upstream of the pressure regulator.

17. The system according to claim 9, wherein the hydrogen fueling system includes: a hydrogen fuel storage tank for storing hydrogen fuel; a tank pressure regulator connected between the hydrogen fuel storage tank and the pressure regulator; and the ECU is configured to detect the leakage or failure of the hydrogen fueling system downstream of the tank pressure regulator.

18. An apparatus for detecting a leakage or failure of a hydrogen fueling system for a spark- ignited combustion engine, the apparatus comprising: a non-transitory memory medium configured to store instructions executable by a processor to perform the acts of: operate the spark-ignited combustion engine with hydrogen fuel using the hydrogen fueling system;determine a rail pressure error based on a difference between a commanded rail pressure associated with a fuel rail of the hydrogen fueling system and an actual pressure associated with the fuel rail; determine a rail pressure governor error based on a speed of the spark-ignited combustion engine; and determine the leakage or failure of the hydrogen fueling system is present in response the rail pressure error falling outside the allowable rail pressure governor error.

19. The apparatus of claim 18, wherein the non-transitory memory medium stores instructions executable by the processor to perform the acts of: determine the leakage or failure of the hydrogen fueling system is present only if the rail pressure error falling outside the allowable the rail pressure governor error over a calibratable time threshold.

20. The apparatus of claim 18, wherein the non-transitory memory medium stores instructions executable by the processor to perform the acts of: adjust the operation of the spark-ignited combustion engine in response to the leakage or failure of the hydrogen fueling system hydrogen fuel leak condition.

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