Control unit and method for predicting backfire in the intake manifold of a hydrogen engine

Abstract

Title: Control Unit and Method for Predicting Backfire in an Intake Manifold of a Hydrogen Engine. The control unit 112 predicts backfire in the intake manifold 106 of the vehicle's hydrogen engine. The intake manifold includes a hydrogen injector 108. Gaseous hydrogen is injected through said hydrogen injector 108 and sent to a cylinder 102 of said engine. Said control unit is configured to: detect an accumulation 104 of hydrogen using a hydrogen sensor 110 positioned in said intake manifold 106, compare the detected hydrogen accumulation 104 to a predetermined threshold, and predict the probability of backfire occurring in said intake manifold 106 based on the comparison. Figure for the abstract: Fig. 1

Description

Title of the invention: Control unit and method for predicting backfire in the intake manifold of a hydrogen engine technical field

[0001] The present invention relates to a control unit and a method for predicting backfire in an intake manifold of a hydrogen engine of a vehicle.

[0002] Background of the invention:

[0003] Gaseous hydrogen is a carbon-neutral fuel with a very high calorific value and ignites very quickly. In a vehicle's hydrogen engine, due to the use of hydrogen as fuel, backfire is a consequence of combustion. Backfire in the hydrogen engine causes a flame near a point, such as a spark plug or an intake valve, and propagates through the intake manifold, damaging engine parts and impairing engine performance. Detecting backfire and its intensity in such scenarios is crucial, and no such mechanism is currently available that would enable its detection.

[0004] According to prior document JP5321690, a method is described that prevents the production of backfire and / or afterburning by gradually increasing the flow velocity of residual gaseous fuel in an intake system and / or an exhaust system, and then starting a motor-by-motor control in a state where the gaseous fuel supply is interrupted in a motor-start operation. CONSTRUCTION: A hydrogen flow regulating valve and a closed-type solenoid valve are provided in a hydrogen supply line downstream of a pressure regulator, and a hydrogen injection valve is provided in hydrogen supply lines downstream of the latter for injecting gaseous hydrogen.When both hydrogen concentrations in an exhaust passage and in an intake passage are determined by hydrogen sensors to exceed a setpoint value, a pump is actuated to open valves in gas passages and exhaust gas in a reservoir is gradually introduced into the exhaust and intake passages so that residual gaseous hydrogen is discharged in a mode of this kind, namely that the . The flow rate is gradually reduced. The solenoid valve is then opened for startup. This prevents backfires and / or afterburning.

[0005] The invention relates to a control unit for predicting backfire in an intake manifold of a hydrogen engine.

[0006] According to the invention, the intake manifold comprises a hydrogen injector, into which gaseous hydrogen is injected via said hydrogen injector and sent to a cylinder of said engine, characterized in that said control unit is configured to: a. detect an accumulation of hydrogen by using a hydrogen sensor placed in said intake manifold; b. compare the detected hydrogen accumulation to a predetermined threshold, and c. predict a probability of occurrence of a backfire in said intake manifold based on the comparison.

[0007] Preferably: - said hydrogen injector is fixed in an orifice of said intake manifold and said hydrogen sensor is positioned downstream of said orifice in the intake manifold at a predetermined distance from said orifice, - the control unit is configured to perform control measures after a backfire is predicted, wherein said control measures are at least one selected from the group including valve control optimization, fuel injection timing optimization, lambda increase, water injection and exhaust gas recirculation, - The control unit is configured to: a. calculate a probability of the occurrence of said backfire based on a ratio between the determined hydrogen accumulation and the air in said intake manifold, and b. disable said hydrogen injection and expel said accumulated hydrogen based on said calculated probability. - said optimization of fuel injection time includes shifting at least one of an injection start angle and an injection end angle accordingly.

[0008] The invention also relates to a method for predicting backfire in an intake manifold of a hydrogen engine, said intake manifold comprising a hydrogen injector, into which gaseous hydrogen is injected via said hydrogen injector and sent to a cylinder of said engine. motor, the process being carried out by a control unit, characterized in that said process comprises the stages of: a. detection of a hydrogen accumulation using a hydrogen sensor placed in said intake manifold; b. compare the detected hydrogen accumulation to a predetermined threshold, and c. prediction of the probability of occurrence of a backfire in said intake manifold based on the comparison.

[0009] Preferably: - said hydrogen injector is fixed in an orifice of said intake manifold and said hydrogen sensor is positioned downstream of said orifice in the intake manifold at a predetermined distance from said orifice, - the process includes carrying out control measures after having predicted said probability of occurrence of a backfire, said control measures being at least one chosen from a group including optimization of valve control, optimization of fuel injection time, increase of lambda, water injection and exhaust gas recirculation, - The process includes the following stages: a. calculate a probability of the occurrence of said backfire based on a ratio between the determined hydrogen accumulation and the air in said intake manifold, and b. disable said hydrogen injection and expel said accumulated hydrogen based on said calculated probability. - the optimization of fuel injection time, said process includes shifting an injection start angle, an injection end angle accordingly.

[0010] Brief description of the attached drawings:

[0011] An embodiment of the invention is described with reference to the following accompanying drawings:

[0012] Figure 1 illustrates a functional diagram of a control unit for predicting backfire in an intake manifold of a hydrogen engine of a vehicle according to an embodiment of the present invention and

[0013] Fig. 2 illustrates various stages carried out in the operation to predict backfire in the intake manifold of the hydrogen engine of the vehicle according to the present invention.

[0014] Detailed description of embodiments:

[0015] Figure 1 is a block diagram of a control unit 112 for predicting backfire in an intake manifold 106 of a hydrogen engine according to an embodiment of the present invention. The intake manifold 106 includes a hydrogen injector 108. Gaseous hydrogen is injected through the hydrogen injector 108 and sent to a cylinder of the hydrogen engine. The control unit 112 is characterized in that it is configured to detect a concentration / accumulation of hydrogen 104 using a hydrogen sensor 110 positioned in the intake manifold 106. The control unit 112 is configured to compare the detected hydrogen accumulation 104 to a predetermined threshold. The control unit 112 is configured to predict the probability of a backfire occurring in the intake manifold 106 based on the comparison.The predetermined threshold and the amount of hydrogen 104 accumulated in the intake manifold 106, at which a backfire occurs in the intake manifold 106. If the accumulated hydrogen concentration 104 is above the predetermined threshold, the control unit 112 predicts the probability of a backfire occurring.

[0016] According to the embodiment of the present invention, the hydrogen injector 108 is fixed to an orifice in the intake manifold 106, and the hydrogen sensor 110 is positioned upstream of the orifice in the intake manifold 106 and at a predetermined distance from the orifice. The predetermined distance varies with the design of the intake manifold 106, and consequently, the positioning of the hydrogen sensor 110 changes. The hydrogen sensor 110 detects the accumulation 104 of hydrogen and sends the data to the control unit 112, based on which the control unit 112 predicts the probability of backfire occurrence.

[0017] According to the embodiment of the present invention, the control unit 112, after anticipating backfire, takes control measures. The control measures are at least one selected from the group consisting of optimizing valve control, optimizing fuel injection timing, increasing lambda, water injection, and exhaust gas recirculation.

[0018] Each of the control measures is explained below. Valve control is a key factor in preventing backfires. If fuel injected into the intake manifold 106 does not completely enter an engine combustion chamber before the intake valve closes, or if fuel is injected before the intake valve opens, hydrogen may accumulate 104 in the intake manifold 106, causing backfires. By controlling the opening and closing rate of the intake valve based on the response of the hydrogen sensor 110, Hydrogen accumulation is prevented. The ignition timing advances or retards combustion to lower the cylinder temperature. The ignition source in the case of backfire in a hydrogen engine is the high temperature of engine components, such as the intake valve, spark plug, etc. Due to hydrogen accumulation and the high temperature of these components, the probability of backfire occurs increases. Based on the input from the hydrogen sensor, sufficient ignition timing is retarded to control and maintain a temperature below the hydrogen auto-ignition temperature. The lambda augmentation strategy is used to control the cylinder temperature and NOx emissions.Increasing the lambda value refers to improving the air quality in the air-fuel ratio, which slows down the combustion process and the propagation of the hydrogen flame. Slowing down the combustion process helps lower the rate of heat release in the combustion chamber, thus reducing the cylinder temperature. Water injection into the intake manifold (106) is a strategy in which water is injected into the intake manifold (106), where it passes into the combustion chamber and absorbs heat, reducing the cylinder temperature. These control measures prevent hydrogen buildup (104), reduce the likelihood of backfires in the intake manifold (106), and increase the longevity and robustness of the hydrogen engine.

[0019] According to the embodiment of the present invention, the control unit 112 calculates the probability of backfire based on a ratio between the determined hydrogen accumulation 104 and the air in the intake manifold 106. The control unit 102 deactivates the hydrogen injection and expels the accumulated hydrogen 106 based on the calculated probability, thereby reducing the probability of backfire.

[0020] According to one embodiment of the present invention, optimizing the fuel injection timing includes shifting at least one of the injection start angle or injection end angle accordingly to prevent hydrogen accumulation in the intake manifold 106, thereby reducing the probability of backfire. Thus, for example, in the present scenario, once hydrogen accumulation 104 is determined, the control unit 112 shifts the injection angle and interrupts injection for a few cycles until the accumulated hydrogen 104 is expelled. The start of the injection angle or the end of an injection angle is associated with the lifting of the intake valve or exhaust valve. Both intake and exhaust valves are electronically controlled.

[0021] According to one embodiment of the present invention, the control unit 112 is provided with the necessary circuits for signal detection, acquisition, and processing. The control unit 112 is a unit comprising an input interface, output interfaces having pins or access points, a memory element such as random access memory (RAM) and / or read-only memory (ROM), an analog-to-digital converter (ADC) and a digital-to-analog converter (DAC), clocks, timers, counters, and at least one processor (capable of implementing machine learning) connected to each other and to the other components by communication bus channels.The memory element (not shown) is pre-loaded with logic and instructions, application programs, modules, models, and / or values / threshold ranges, reference values, predefined / predetermined criteria / conditions, lists, and knowledge sources, which are accessed by at least one processor, as well as by defined routines. The internal components of the control unit 112 are not further explained as they are part of the prior art and cannot be considered exhaustive. The control unit 112 may also include communication units such as transmitters and receivers for wireless or wired communication, such as Global System for Mobile Communications (GSM), 3G, 4G, 5G, Wi-Fi, Bluetooth, Ethernet, serial networks, etc.The 112 control unit can be implemented as a system-in-a-package (SiP), a system-on-a-chip (SoC), or any other known type. Examples of a 112 control unit include, but are not limited to, a microcontroller, a microprocessor, a microcomputer, electronic control units (ECUs), etc.

[0022] According to the embodiment of the present invention, the operation of the control unit 112 is described below. The control unit 112 determines the backfire in the intake manifold 106 of the vehicle's hydrogen engine. The hydrogen injector 108 is attached to an orifice in the intake manifold 106, and the hydrogen sensor 110 is positioned downstream of the orifice at a predetermined distance. The orifice is specially designed to house the hydrogen injector 108. The hydrogen sensor 110 determines the hydrogen accumulation 104 and sends a signal to the control unit 112. The control unit 112 takes control measures, and these measures are selected from a group including valve timing optimization, fuel injection timing optimization, lambda increase, and injection. water and exhaust gas recirculation. These control measures reduce the probability of backfires.

[0023] Figure 2 illustrates various stages carried out in the operation of predicting backfire in the intake manifold 106 of the hydrogen engine of the vehicle, according to the present invention. The intake manifold 106 includes the hydrogen injector 108. Gaseous hydrogen is injected via the hydrogen injector 108 and sent to the engine cylinder 102. The method comprises several stages, among which stage 202 includes detecting, by the control unit 112, the accumulation 104 of hydrogen using the hydrogen sensor 110 in the intake manifold 106. Stage 204 includes comparing, by the control unit 112, the detected hydrogen accumulation 104 to the predetermined threshold. Stage 206 includes predicting by control unit 112 the probability of the occurrence of a backfire in the intake manifold 106 based on the comparison.The predetermined threshold and the amount of hydrogen 104 accumulated in the intake manifold 106, for which backfire occurs in the intake manifold 106 near the intake valve.

[0024] According to the method, step 204 comprises positioning the hydrogen sensor 110. The hydrogen injector 108 is fixed to the orifice, and the hydrogen sensor 110 is positioned upstream of the orifice in the intake manifold 106 and at a predetermined distance from the orifice. The accumulation of hydrogen 104 is continuously detected by the hydrogen sensor 110, and the detected signal is received by the control unit 112. The method comprises predicting, by the control unit 112, the probability of backfire occurrence via the hydrogen sensor 110, by comparing it to the predetermined threshold. After prediction, the method comprises performing control measures by the control unit 112.The control measures include at least one from the following group: valve timing optimization, fuel injection timing optimization, lambda sensor increase, water injection, and exhaust gas recirculation. Furthermore, by optimizing the fuel injection timing, the process includes adjusting the start or end of injection accordingly. The control measures prevent the possibility of backfire.

[0025] According to the method, stage 206 includes calculating the probability of backfire based on the ratio between the determined hydrogen accumulation 104 and the air in the intake manifold 106. Based on the calculated probability, the method includes deactivating the injection and purging the accumulated hydrogen 104. Once the accumulated hydrogen 104 has been purged, the probability of backfire decreases and the control unit 112 begins The injection of hydrogen for the next cycle. The chase involves injecting hydrogen into the engine in a controlled manner.

[0026] The present invention describes the control unit 112 and the method for predicting the occurrence of backfire in the intake manifold 106 of the hydrogen engine. The control unit 112 detects the accumulation 104 of hydrogen in the intake manifold 106 using the hydrogen sensor 110 and, based on a comparison with the threshold, predicts the probability of backfire occurrence. Based on the prediction, the control unit 112 takes control measures and prevents the possibility of severe backfire and damage to various components. To account for the damage to various components, adaptive logic is included in the control unit 112.The adaptive logic creates additional correction factors (or control measures) to correct the valve timing. Using this correction factor, the control unit 112 shifts the injector operating time, which is specific to a particular operating area based on the hydrogen sensor's response. This predicts the occurrence of backfire, thus providing a robust control system that predicts backfire and improves the performance and longevity of a hydrogen-powered engine.

[0027] It is understood that the embodiments explained in the above description are merely illustrative and do not limit the scope of the invention. Many of these embodiments and other modifications and changes to the embodiment explained in the description are envisaged.

Claims

Demands

1. A control unit (112) for predicting backfire in an intake manifold (106) of a hydrogen engine, said intake manifold (106) comprising a hydrogen injector (108), into which gaseous hydrogen is injected through said hydrogen injector (108) and sent to a cylinder (102) of said engine, characterized in that said control unit (112) is configured to: a. detect an accumulation (104) of hydrogen using a hydrogen sensor (110) positioned in said intake manifold (106); b. compare the detected accumulation (104) of hydrogen to a predetermined threshold, and c. predict a probability of occurrence of backfire in said intake manifold (106) based on the comparison.

2. The control unit (112) as claimed in claim 1, wherein said hydrogen injector (108) is fixed in an orifice of said intake manifold (106) and said hydrogen sensor (110) is positioned downstream of said orifice in the intake manifold (106) at a distance determined in advance of said orifice.

3. The control unit (112) as claimed in claim 1 or 2, configured to perform control measures after prediction of a backfire, wherein said control measures are at least one selected from the group comprising valve control optimization, fuel injection timing optimization, lambda increase, water injection and exhaust gas recirculation.

4. The control unit (112) as claimed under any one of the preceding claims, configured to: a. calculate a probability of the occurrence of said backfire on the basis of a ratio between the determined accumulation (104) of hydrogen and the air in said intake manifold (106), and b. disable said hydrogen injection and expel said accumulated hydrogen (104) on the basis of said calculated probability.

5. The control unit (112) as claimed in claim 3, wherein said fuel injection timing optimization includes shifting at least one of an injection start angle and an injection end angle accordingly.

6. A method for predicting backfire in an intake manifold (106) of a hydrogen engine, said intake manifold (106) comprising a hydrogen injector (108), wherein gaseous hydrogen is injected through said hydrogen injector (108) and sent to a cylinder (102) of said engine, the method being carried out by a control unit (112), characterized in that said method comprises the steps of: a. detecting an accumulation (104) of hydrogen using a hydrogen sensor (110) positioned in said intake manifold (106); b. comparing the detected hydrogen accumulation (104) to a predetermined threshold, and c. predicting a probability of backfire occurring in said intake manifold (106) based on the comparison.

7. The method as claimed in claim 6, wherein said hydrogen injector (108) is fixed in an orifice of said intake manifold (106) and said hydrogen sensor (110) is positioned downstream of said orifice in the intake manifold (106) at a distance determined in advance of said orifice.

8. The method as claimed in claim 6 or 7, comprising performing control measures after predicting the probability of backfire occurrence, said control measures being at least one selected from a group comprising valve control optimization, optimization fuel injection timing, lambda increase, water injection and exhaust gas recirculation.

9. The method as claimed in any one of claims 6 to 8, comprising the stages of: a. calculating a probability of the occurrence of said backfire on the basis of a ratio between the determined accumulation (104) of hydrogen and air in said intake manifold (106), and b. disabling said hydrogen injection and expelling said accumulated hydrogen (104) on the basis of said calculated probability.

10. The method as claimed in claim 8, wherein in the optimization of fuel injection time, said method comprises shifting an injection start angle, an injection end angle accordingly.

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