Claims:
1. A method for regulating NOx emissions from a hydrogen internal combustion engine (1), wherein the hydrogen internal combustion engine (1) is in fluid communication with a hydrogen injector (2), an exhaust gas recirculation unit [EGR] (10) and a water injection unit (3), the method comprising:
determining, by an electronic control unit [ECU] (4), quantity of NOx in exhaust gas from the hydrogen internal combustion engine (1), based on a signal from a NOx sensor (5) disposed in an exhaust system (100) of the hydrogen internal combustion engine (1);
regulating, by the ECU (4), at least one of the hydrogen injector (2), the EGR unit (10) and the water injection unit (3), to control a quantity of hydrogen being injected by the hydrogen injector (2), a quantity of the exhaust gas being recirculated by the EGR unit (10) and a quantity of water being impinged from the water injection unit (3), respectively, for regulating NOx emissions in the exhaust gas.

2. The method as claimed in claim 1, wherein the ECU (4) regulates quantity of water being impinged into the hydrogen internal combustion engine (1) by selectively operating a pump (6) of the water injection unit (3).

3. The method as claimed in claim 2, comprises determining, by the ECU (4), quantity of water in a water storage tank (7) of the water injection unit (3) based on a signal received from a water level sensor (8), wherein the ECU (4) is configured to operate the pump (6) when the determined quantity of water in the water storage tank (7) is at least at a predetermined limit.

4. The method as claimed in claim 1, wherein ECU (4), regulates the quantity of exhaust gas being recirculated into the hydrogen internal combustion engine (1) by selectively operating at least one EGR valve (9) of the EGR unit (10) , wherein the EGR valve (9) is operated to a closed condition when at least one of NOx emission exceeds a predefined value and quantity of water in the water storage tank (7) is lower than the predetermined limit.

5. The method as claimed in claim 1, wherein controlling, by the ECU (4), quantity of hydrogen being injected to the hydrogen internal combustion engine (1) to de-rate power output from the hydrogen internal combustion engine (1), when at least one of quantity of water in the water storage tank (7) is lower than the predetermined limit and the at least one EGR valve (9) is operated to the closed condition.

6. The method as claimed in claim 1, wherein the ECU (4) is configured to determine quantity of NOx emission in the exhaust based on variation in at least one of speed and load acting on the hydrogen internal combustion engine (1).

7. A system (100) for regulating NOx emissions from a hydrogen internal combustion engine (1), wherein the hydrogen internal combustion engine (1) is in fluid communication with a hydrogen injector (2), an exhaust gas recirculation [EGR] unit (10) and a water injection unit (3), the system (100) comprising:
NOx sensor (5) disposed in an exhaust system (100) of the hydrogen internal combustion engine (1), the NOx sensor (5) is configured to generate a signal corresponding to quantity of NOx in the exhaust emitted from the hydrogen internal combustion engine (1); and
an electronic control unit, communicatively coupled to the NOx sensor (5), the EGR unit (10), the hydrogen injector (2) and the water injection unit (3), wherein the electronic control unit is configured to:
determine quantity of NOx in the exhaust emitted from the hydrogen internal combustion engine (1), based on the signal from the NOx sensor (5); and
regulate, at least one of the hydrogen injector (2), the EGR unit (10) and the water injection unit (3), to control a quantity of hydrogen being injected by the hydrogen injector (2), a quantity of the exhaust gas being recirculated by the EGR unit (10) and a quantity of water being impinged from the water injection unit (3), respectively, for regulating NOx emission in the exhaust gas.

8. The system (100) as claimed in claim 7, wherein the ECU (4) is configured to determine quantity of water in the water storage tank (7) by a water level sensor (8) and wherein the ECU (4) is configured to operate a pump (6) when the water in the water storage tank (7) is at least at a predetermined limit, to regulate quantity of water being impinged into the hydrogen internal combustion engine (1) based on determined quantity of water.

9. The system (100) as claimed in claim 7, wherein the ECU (4) is configured to selectively operate at least one EGR valve (9) of the EGR unit (10), to regulate quantity of exhaust gas being recirculated into the hydrogen internal combustion engine (1), wherein the at least one EGR valve (9) is operated to a closed condition when at least one of NOx emission exceeds a predefined value and quantity of water in the water storage tank (7) in lower than the predetermined limit.

10. The system (100) as claimed in claim 7, wherein the electronic control unit is configured to control quantity of hydrogen being injected to the hydrogen internal combustion engine (1), to de-rate power output from the hydrogen internal combustion engine (1), when at least one of quantity of water in the water storage tank (7) in lower than the predetermined limit and the at least one EGR valve (9) is operated to the closed condition.

11. A vehicle comprising a system (100) as claimed in claim 7.
, Description:TECHNICAL FIELD
The present disclosure, in general, relates to the field of automobiles. Particularly, but not exclusively, the present disclosure relates to a hydrogen internal combustion engine [that is, internal combustion engine run by hydrogen as fuel]. Further, embodiments of the present disclosure relate to a system and a method for regulating NOx emissions from a hydrogen internal combustion engine.

BACKGROUND OF THE DISCLOSURE
Internal combustion engines, or generally referred to as IC engines, are prime movers that are configured to convert chemical energy to mechanical energy, in order to perform defined work. In general, the internal combustion engines employ charge having air mixed with fuel such as, but not limited to, petroleum products, to suitably combust and produce energy leaving some by-products of such combustion. With advent of technology, to minimize use of non-renewable resources such as petroleum products in automotive industries at least for locomotive purposes, IC engines capable of running with alternative fuels including, but not limited to, hydrogen fuels, have been developed. The hydrogen fuel performs similar functions as that of petroleum products, however, the by-product of such IC engines include nitrogen oxide, carbon dioxide, and water vapor traces after combustion.

Burnt gases of the exhaust from a hydrogen internal combustion engine generally contains at least carbon dioxide and nitrogen oxides, that are to be treated prior being dispensed to the surroundings or atmosphere. The treatment of such burnt gases include catalytic reduction units, reductant injection units and the like, which may inherently increase overall bulkiness of the IC engine, while adding to the weight of the vehicle. Also, if the burnt gases are released without treatment from the vehicle, such burnt gases may cause harm to surroundings due to chemical properties, and hence, treatment of the burnt gases is of utmost importance. Specifically, treatment of nitrogen oxides are required to a greater degree in order to minimize effects of such nitrogen oxides on resources including, but not limited to, air and water.

To overcome such situation, with advent of technology, various system and methods have been developed where nitrogen oxides can be carefully treated. Some of such configurations include delayed fuel injection systems, modifications to fuel nozzle or injectors, changing compression ratio of the IC engine, and other systems or methods that may be employed in conjunction with catalytic reduction units. However, such configurations tend to affect working of the IC engine during long run, as components involved therein tends to incorporate increased mechanical movements that may cause wear out and may require frequent servicing/replacement to maintain efficiency of the IC engine. In addition to the aforesaid system, one alternative configuration is by including an exhaust gas recirculation [EGR], where the burnt gases are recirculated to the IC engine for further combustion in order to reduce carbon and nitrogen compounds in the burnt gases of the exhaust. Nonetheless, during operation of the vehicle under varying loaded conditions, composition of the nitrogen oxides in the exhaust may vary even with operation of the EGR, whereby rendering that the quantity of nitrogen oxide may reach beyond an allowable prescribed limit.

The present disclosure is directed to overcome one or more limitations stated above or any other limitations associated with the conventional configuration of the hydrogen internal combustion engines.

SUMMARY OF THE DISCLOSURE

One or more shortcomings of the prior art are overcome by a method and a system as claimed and additional advantages are provided through the method and the system as claimed in the present disclosure. Additional features and advantages are realized through the techniques of the present disclosure. Other embodiments and aspects of the disclosure are described in detail herein and are considered a part of the claimed disclosure.

In one non-limiting embodiment of the present disclosure a method for regulating NOx emissions from a hydrogen internal combustion engine is disclosed. The hydrogen internal combustion engine is in fluid communication with a hydrogen injector, an exhaust gas recirculation [EGR] unit and a water injection unit. The method includes steps of determining quantity of NOx in exhaust from the hydrogen internal combustion engine, by an electronic control unit [ECU] based on a signal from a NOx sensor disposed in an exhaust system of the hydrogen internal combustion engine. The ECU is configured to regulate at least one of the hydrogen injector, the exhaust gas recirculation [EGR] unit and the water injection unit, to control a quantity of hydrogen being injected by the hydrogen injector, a quantity of the exhaust gas being recirculated by the EGR unit and a quantity of water being impinged from the water injection unit, respectively, for regulating NOx emission in the exhaust gas.

In an embodiment of the present disclosure, the ECU regulates quantity of water being impinged into the hydrogen internal combustion engine by selectively operating a pump of the water injection unit.

In an embodiment of the present disclosure, the method further comprises determining quantity of water in a water storage tank of the water injection unit by the ECU, based on a signal received from a water level sensor. The ECU is configured to operate the pump when the determined quantity of water in the water storage tank is at least at a predetermined limit.

In an embodiment of the present disclosure, the ECU is configured to regulate the quantity of exhaust gas being recirculated into the hydrogen internal combustion engine by selectively operating the at least one EGR valve of the EGR unit. The at least one EGR valve is operated to a closed condition when at least one of NOx emission exceeds a predefined value and quantity of water in the water storage tank in lower than the predetermined limit.

In an embodiment of the present disclosure, the ECU is configured to control quantity of hydrogen being injected to the hydrogen internal combustion engine to de-rate power output from the hydrogen internal combustion engine, when at least one of quantity of water in the water storage tank in lower than the predetermined limit and the at least one EGR valve is operated to the closed condition.

In an embodiment of the present disclosure, the ECU is configured to determine quantity of NOx emission in the exhaust based on variation in at least one of speed and load acting on the hydrogen internal combustion engine.

In another non-limiting embodiment of the present disclosure, a system for regulating NOx emissions from a hydrogen internal combustion engine, is disclosed. The hydrogen internal combustion engine is in fluid communication with a hydrogen injector, an exhaust gas recirculation [EGR] unit and a water injection unit. The system includes a NOx sensor, disposed in an exhaust system of the hydrogen internal combustion engine, configured to generate a signal corresponding to quantity of NOx in the exhaust emitted from the hydrogen internal combustion engine. The system further includes an electronic control unit, communicatively coupled to the NOx sensor, of the EGR unit and the water injection unit. The electronic control unit [ECU] is configured to determine quantity of NOx in the exhaust emitted from the hydrogen internal combustion engine, based on the signal from a NOx sensor. Upon determining the NOx quantity, the ECU is configured to control at least one of the hydrogen injector, the EGR unit and the water injection unit, to control a quantity of hydrogen being injected by the hydrogen injector, a quantity of the exhaust gas being recirculated by the EGR unit and a quantity of water being impinged from the water injection unit, respectively. Based on controlling at least one of the hydrogen injector, the EGR and the water injection unit, NOx emission in the exhaust gas is regulated.

The foregoing summary is illustrative only and is not intended to be in any way limiting. In addition to the illustrative aspects, embodiments, and features described above, further aspects, embodiments, and features will become apparent by reference to the drawings and the following detailed description.

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS

The novel features and characteristic of the disclosure are set forth in the appended claims. The disclosure itself, however, as well as a preferred mode of use, further objectives, and advantages thereof, will best be understood by reference to the following detailed description of an illustrative embodiment when read in conjunction with the accompanying figures. One or more embodiments are now described, by way of example only, with reference to the accompanying figures wherein like reference numerals represent like elements and in which:

Figure 1 illustrates a block diagram of a system for regulating NOx emissions from a hydrogen internal combustion engine, in accordance with an embodiment of the present disclosure.

Figure 2 illustrates a schematic diagram of the system in Figure 1.

Figure 3 is a flow chart illustrating sequence of steps involved in a method for operating the system of Figures 1 and 2.

The figures depict embodiments of the disclosure for purposes of illustration only. One skilled in the art will readily recognize from the following description that alternative embodiments of the system and method illustrated herein may be employed without departing from the principles of the disclosure described herein.

DETAILED DESCRIPTION

While the embodiments in the disclosure are subject to various modifications and alternative forms, specific embodiments thereof has been shown by the way of example in the figures and will be described below. It should be understood, however that it is not intended to limit the disclosure to the particular forms disclosed, but on the contrary, the disclosure is to cover all modifications, equivalents, and alternative falling within the scope of the disclosure.

The terms “comprises”, “comprising”, or any other variations thereof used in the disclosure, are intended to cover a non-exclusive inclusions, such that a device, assembly, mechanism, system, method that comprises a list of components does not include only those components but may include other components not expressly listed or inherent to such system, or assembly, or device. In other words, one or more elements in a system proceeded by “comprises… a” does not, without more constraints, preclude the existence of other elements or additional elements in the system or method.

Embodiments of the present disclosure disclose a system and a method for regulating NOx emissions from a hydrogen internal combustion engine. The hydrogen internal combustion engine is in fluid communication with a hydrogen injector, an exhaust gas recirculation [EGR] unit and a water injection unit. The system includes a NOx sensor, disposed in an exhaust system of the hydrogen internal combustion engine, configured to generate a signal corresponding to quantity of NOx in the exhaust emitted from the hydrogen internal combustion engine. The system further includes an electronic control unit, communicatively coupled to the NOx sensor, of the EGR unit and the water injection unit. The electronic control unit [ECU] is configured to determine quantity of NOx in the exhaust emitted from the hydrogen internal combustion engine, based on the signal from a NOx sensor. Upon determining the NOx quantity, the ECU is configured to control at least one of the hydrogen injector, the EGR and the water injection unit, to control a quantity of hydrogen being injected by the hydrogen injector, a quantity of the exhaust gas being recirculated by the EGR unit and a quantity of water being impinged from the water injection unit, respectively. Based on controlling at least one of the hydrogen injector, the EGR and the water injection unit, NOx emission in the exhaust gas is regulated. Thus, NOx emissions from the hydrogen internal combustion engine are regulated to zero or a nearly zero-value which is under regulatory pre-set value, without having to compromise on load capacity, and durability of such hydrogen internal combustion engine.

In an embodiment, the term “emissions” refers to exhaust gases or burnt gases that may be produced as a by-product of combustion in the hydrogen internal combustion engine. The emissions may include, but may not be limited to, carbon dioxide, nitrogen oxides, water vapor and other gases in negligible proportion that may be produced due to elements and/or compounds in the air. Primarily, nitrogen oxides [or referred to as NOx] are produced as one of the by-products due to considerable amount of nitrogen gas in the air being used for combustion in the hydrogen internal combustion engine. Also, pre-set quantity of NOx allowable in the emission is dependent on regulatory norms of jurisdictions in which the hydrogen internal combustion engine may be operated. As such, operating parameters for regulating NOx may be dependent on various factors based on the jurisdictions.

In an embodiment, combustion in the hydrogen internal combustion engine may be between the hydrogen injected as fuel and oxygen in the air being supplied, while other constituent gases in the air may also undergo sub-combustion due to energy and thermal elevation produced therefrom.

The disclosure is described in the following paragraphs with reference to Figures 1 and 3. In the figures, the same element or elements which have same functions are indicated by the same reference signs. It is to be noted that, the vehicle and the internal combustion engine are not illustrated in the figures for the purpose of simplicity. One skilled in the art would appreciate that the system and the method as disclosed in the present disclosure may be used in any vehicles that is capable of being driven by the hydrogen internal combustion engine, where such vehicle may include, but not be limited to, light vehicles, passenger vehicles, commercial vehicles, and the like.

Figure 1 is an exemplary embodiment of the present disclosure which illustrates a system (100) for regulating NOx emissions from a hydrogen internal combustion engine (1). The system (100) includes a hydrogen injector (2),configured to inject a determined quantity of hydrogen to each cylinder of the hydrogen internal combustion engine (1). The hydrogen internal combustion engine (1) is configured to receive hydrogen in a gaseous form from the hydrogen injector (2), where the hydrogen is configured to act as a fuel for operation of the hydrogen internal combustion engine (1). In an embodiment, the hydrogen may be supplied from a hydrogen source including, but not limited to, a hydrogen fuel cell, a hydrogen tank, and any other source capable of generating or storing hydrogen for supplying to the hydrogen internal combustion engine (1) via the hydrogen injector (2). The hydrogen injected into the hydrogen internal combustion engine (1) is supplemented by injecting a predefined quantity of air [that is, proportionally dependent on quantity of hydrogen being injected], which acts as an oxidizing agent for operation of the hydrogen internal combustion engine (1). The air may be received from the atmosphere or may be supplied from an accumulator or pressuring source associated with the system (100). In an embodiment, the hydrogen and the air may mix to form a charge, that may be subjected to combustion by either spark ignition or compression ignition, based on capacity and nature of the hydrogen internal combustion engine (1).

Further, as the hydrogen and the air undergo combustion process in the hydrogen internal combustion engine (1), thereby producing a mechanical power, heat energy is produced along with by-products including, but not limited to, carbon dioxide, NOx, water vapor and other gases in minimal composition. The carbon dioxide produced may be separately treated, while quantity of NOx emissions in the exhaust is configured to be determined, reduced and/or regulated by the system (100). To determine the NOx emissions in the exhaust, a NOx sensor (5) may be disposed in an exhaust system (100) of the hydrogen internal combustion engine (1) to detect quantity of NOx emissions. Additionally, to reduce and/or regulate quantity of NOx emissions in the exhaust, the system (100) further includes an exhaust gas recirculation [EGR (10)] unit and a water injection unit (3). In an embodiment, the EGR unit (10) and water injection unit (3) may be complemented by a catalytic convertor and/or reductant injector unit, in order to reduce and/or regulate quantity of NOx emissions in the exhaust gas. In addition, the NOx sensor (5) may be positioned before the exhaust gas is channelized to the EGR (10), however, the NOx sensor (5) may also be positioned anywhere along the EGR unit (10) and before an inlet manifold of the hydrogen internal combustion engine (1). It may also be inherent that by increasing number of NOx sensors, the quantity of NOx emissions in the exhaust gas at various positions may be determined, which should be construed within operation of the system (100).

In the illustrative embodiment, the NOx sensor (5) may be communicatively coupled to an electronic control unit [hereafter also referred to as ECU (4)], where the NOx sensor (5) is configured to detect NOx emissions in the exhaust gas and generate a signal corresponding to quantity of NOx in the exhaust gas emitted from the hydrogen internal combustion engine (1). Based on the signal from the NOx sensor (5), the ECU (4) is configured to determine quantity of NOx in the exhaust gas, in order to suitably regulate at least one of the hydrogen injector (2), the EGR unit (10) and the water injection unit (3). By regulating the hydrogen injector (2), the ECU (4) is configured to control a quantity of hydrogen being injected by the hydrogen injector (2), whereby the ECU (4) is configured to control amount of air, and in-turn nitrogen gas in the air, being injected into the hydrogen internal combustion engine (1). With such configuration, the ECU (4) is configured to control power output from the hydrogen internal combustion engine (1), where reducing quantity of hydrogen being supplied, the ECU (4) is configured to de-rate power output from the hydrogen internal combustion engine (1) and inherently, reduce NOx emissions from the hydrogen internal combustion engine (1).

The system (100) further includes the EGR unit (10) and the water injection unit (3) to regulate NOx emissions from the hydrogen internal combustion engine (1). The ECU (4) is configured to control quantity of hydrogen being injected based on operation of the EGR unit (10) and the water injection unit (3). In an embodiment, the ECU (4) may be configured to either alternatively operate the hydrogen injector (2) with the EGR unit (10) and the water injection unit (3), or the ECU (4) may concurrently control operation of the hydrogen injector (2) with the EGR unit (10) and the water injection unit (3). In an embodiment, the EGR unit (10) and the water injection unit (3) may be positioned in the inlet manifold of the hydrogen internal combustion engine (1) so that, portion of the exhaust gas being recirculated, and water may be injected concurrently with injection of hydrogen into the hydrogen internal combustion engine (1). As detailed in Figure 2, the water injection unit (3) includes a pump (6) fluidly connected to a water storage tank (7), associated with the vehicle. The water pump (6) may be communicatively coupled to the ECU (4) so that, based on an operational signal from the ECU (4), water from the water storage tank (7) may be selectively pumped to be injected into the hydrogen internal combustion engine (1). Further, the ECU (4) may be configured to generate the operational signal to the pump (6) upon determining quantity of water in the water storage tank (7). A water level sensor (8) is configured to detect quantity or level of water in the water storage tank (7). Upon detecting the quantity or level of water, the water sensor is configured to transmit a signal to the ECU (4). Based on the signal from the water level sensor (8), the ECU (4) is configured to compare the quantity of water in the water storage tank (7) with a predetermined limit set in a memory unit [not shown in Figures] associated with the ECU (4). The ECU (4) is configured to generate the operational signal to the pump (6) when the determined quantity of water in the water storage tank (7) is at least at the predetermined limit, while when the operational signal is not transmitted to the pump (6) by the ECU (4), when the determined quantity of water in the water storage tank (7) be less than the predetermined limit. In an example, embodiment, the predetermined limit may be in the range of 10% to 30% of volume of the water storage tank (7). Due to requirement of minimum quantity of water in the water storage tank (7) to be at the predetermined limit, possibility of overhauling of the pump (6) may be avoided. Also, by ensuring that the water in the water storage tank (7) is at least at the predetermined limit, a predefined quantity of water may be selectively injected into the hydrogen internal combustion engine (1). With that injection of water, effects including, but not limited to, aversion of knocking, condensing volume of the exhaust gas remaining in the hydrogen internal combustion engine (1) after an expansion stroke, and the like may be produced. Furthermore, as knocking in the hydrogen internal combustion engine (1) is averted, requirement of controlling quantity of hydrogen being injected through the hydrogen injector (2) may be prevented. In addition, as the water injected into the hydrogen internal combustion engine (1) is configured to condense the exhaust gas remaining after the expansion stroke, defined quantity of hydrogen may be injected to avoid de-rating of the hydrogen internal combustion engine (1) when the NOx emissions exceeds the predefined limit.

Further referring to Figure 2, the EGR unit (10) of the system (100) is configured to recirculate at least a portion of the exhaust gas, where the portion of the exhaust gas may be optionally subjected to cooling prior being recirculated into the hydrogen internal combustion engine (1). As the temperature of the exhaust gas being recirculated is being lowered, heat absorbing capacity of the hydrogen and air being injected to the hydrogen internal combustion engine (1) may be increased, whereby allowing further combustion of such hydrogen and air, to reduce quantity of NOx emissions in the exhaust gas. The EGR unit (10) includes at least one EGR valve (9), which may be controlled by an operation signal from the ECU (4). The at least one EGR valve (9) may be positioned proximal to an exhaust port of the hydrogen internal combustion engine (1) or may be positioned at a defined location in the exhaust system (100), for selectively recirculating defined quantity of the exhaust to the hydrogen internal combustion engine (1). In an embodiment, the at least one EGR valve (9) may be a solenoid, a piezoelectric valve, and any other valve that may be operable between an open condition and a closed condition on receiving the operational signal from the ECU (4). The ECU (4) may be configured to operate the at least one EGR valve (9) to a closed condition, when at least one of NOx emission in the exhaust exceeds the predefined value and quantity of water in the water storage tank (7) is lower than the predetermined limit. With such configuration, the ECU (4) may be configured to selectively operate the hydrogen injector (2) based on signals of the water level sensor (8) and the NOx sensor (5), whereby regulating de-rating of the hydrogen internal combustion engine (1).

In an embodiment, the water level sensor (8) may be including, but not limited to, a reed cell, a proximity sensor, and any other fluid level sensor that may be configured to determine quantity or level of water in the water storage tank (7).

In an embodiment, the water pump (6) may be a positive displacement pump (6), which may be based on factors including but not limited to, configuration in which power is supplied to the water pump (6) [that is, either mechanical and/or electrical], and nature of power being supplied [that is, either electrical power or mechanical power], and the like.

In an embodiment, the ECU (4) may be a centralised control unit of the vehicle or may be a dedicated control unit to the system (100) associated with the centralised control unit of the vehicle. The ECU (4) may also be associated with other control units including, but not limited to, body control unit, engine control unit, and the like. The ECU (4) may be comprised of a processing unit. The processing unit may comprise at least one data processor for executing program components for executing user- or system generated requests. The processing unit may be a specialized processing unit such as integrated system (bus) controllers, memory management control units, floating point units, graphics processing units, digital signal processing units, etc. The processing unit may include a microprocessor, such as AMD Athlon, Duron or Opteron, ARM’s application, embedded or secure processors, IBM PowerPC, Intel’s Core, Itanium, Xeon, Celeron, or other line of processors, etc. The processing unit may be implemented using a mainframe, distributed processor, multi-core, parallel, grid, or other architectures. Some embodiments may utilize embedded technologies like application-specific integrated circuits (ASICs), digital signal processors (DSPs), Field Programmable Gate Arrays (FPGAs), etc.

The ECU (4) may be disposed in communication with one or more memory devices (e.g., RAM, ROM etc.) via a storage interface. The storage interface may connect to memory devices including, without limitation, memory drives, removable disc drives, etc., employing connection protocols such as serial advanced technology attachment (SATA), integrated drive electronics (IDE), IEEE-1394, universal serial bus (USB), fiber channel, small computing system (100) interface (SCSI), etc. The memory drives may further include a drum, magnetic disc drive, magneto-optical drive, optical drive, redundant array of independent discs (RAID), solid-state memory devices, solid-state drives, etc.

Referring now to Figure 3 which is an exemplary embodiment of the present disclosure illustrating a flow chart of a method for regulating NOx emissions from the hydrogen internal combustion engine (1). In an embodiment, the method may be implemented in any vehicle including, but not limited to, motorcycles, cars, trucks, gliders, hovers, and the like, which may be operable by hydrogen internal combustion engine (1).

The method may describe in the general context of processor executable instructions. Generally, the executable instructions may include routines, programs, objects, components, data structures, procedures, modules, and functions, which perform particular functions or implement particular abstract data types.

The order in which the method is described is not intended to be construed as a limitation, and any number of the described method blocks may be combined in any order to implement the method. Additionally, individual blocks may be deleted from the methods without departing from the scope of the subject matter described herein. Furthermore, the method can be implemented in any suitable hardware, software, firmware, or combination thereof.

At block 301, the ECU (4) may be configured to determine quantity of NOx in the exhaust gas from the hydrogen internal combustion engine (1) through the signals from the NOx sensor (5) disposed in the exhaust system (100). The ECU (4) may be configured to compare the quantity of NOx emissions in the exhaust gas as received from the NOx sensor (5) with the predefined limit set in the ECU (4). When the quantity of NOx emissions exceeds the predefined limit, the ECU (4) is configured to regulate at least one of the hydrogen injector (2), the EGR unit (10) and the water injection unit (3).

At block 302, the ECU (4) is configured to regulate the EGR unit (10) and the water injection unit (3), prior regulating operation of the hydrogen injector (2). Due to this, de-rating of the hydrogen internal combustion engine (1) may be avoided, thereby averting power-loss from the hydrogen internal combustion engine (1) during operation at varying loads. Further, the ECU (4) is configured to regulate quantity of water being impinged into the hydrogen internal combustion engine (1) from the water injection unit (3). For regulating the impinging of water, the ECU (4) is configured to determine the quantity of water available in the water storage tank (7) by the water level sensor (8) coupled to the water storage tank (7). Based on determined quantity of water in the water storage tank (7), the ECU (4) is configured to selectively operate the pump (6) to supply water for impinging into the hydrogen internal combustion engine (1). Also, the water being impinged into the hydrogen internal combustion engine (1) may be at an elevated pressure when compared to the pressure in which water is supplied from the water storage tank (7) by the pump (6). In an embodiment, the water injection unit (3) may include at least one of a spray mechanism, a nozzle, an atomizer, and any other component that may impinge and disperse water into the hydrogen internal combustion engine (1).

At block 303, the ECU (4) is configured to regulate the EGR unit (10), where quantity of the exhaust gas being recirculated into the hydrogen internal combustion engine (1) may be controlled by the at least one EGR valve (9). The ECU (4) is configured to control operation of the at least one EGR valve (9) by generating the operating signal based on at least one of NOx emission and the quantity of water in the water storage tank (7). It may be inherent that operation of the at least one EGR valve (9) may also depend on other factors including, but not limited to, load on the hydrogen internal combustion engine (1), gradient of terrain in which a vehicle having the hydrogen internal combustion engine (1) is traversed, temperature of the exhaust gas being recirculated, and the like. The at least one EGR valve (9) may be operated between the open condition and the closed condition by the ECU (4). For example, when NOx emissions in the exhaust gas is less than the predefined value and the quantity of water in the water storage tank (7) is greater than the predetermined limit, then the EGR unit (10) is operated to the open condition by the ECU (4) for recirculating the exhaust gas into the hydrogen internal combustion engine (1). Also, when NOx emissions in the exhaust gas is more than the predefined value and the quantity of water in the water storage tank (7) is less than the predetermined limit, then the EGR unit (10) is operated to the closed condition by the ECU (4) for restricting recirculation of the exhaust gas into the hydrogen internal combustion engine (1). In an embodiment, when the quantity of water in the water storage tank (7) is below the predetermined limit, then the ECU (4) may be configured to indicate such quantity of water to an operator or user via an indication means, which may be including, but not limited to, audio means, visual means, and audio-visual means. Based on the indication, the operator may suitably perform servicing, in order ensure quantity of water to be greater than the predetermined limit. This way, the ECU (4) is configured to determine and regulate quantity of NOx emissions from the hydrogen internal combustion engine (1), without having to de-rate power output from the hydrogen internal combustion engine (1).

At block 304, the ECU (4) is configured to regulate quantity of hydrogen being injected by the hydrogen injector (2). The ECU (4) is configured to regulate operation of the hydrogen injector (2) based on operation of the water injection unit (3) and the EGR (10). For example, when the quantity of NOx emissions in the exhaust gas exceeds the predefined value and that the EGR unit (10) being operated to the closed condition with the quantity of water in the water storage tank (7) being less than the predetermined limit, then the ECU (4) is configured to regulate supply of the hydrogen from the hydrogen injector (2). Due to this, quantity of air being supplied to the hydrogen internal combustion engine (1) may also be regulated [or reduced] in conjunction with supply [that is, reduced quantity] of the hydrogen, whereby rendering that the quantity of nitrogen gas involved in a combustion process of the hydrogen internal combustion engine (1) may be reduced. Such configuration de-rate power output from the hydrogen internal combustion engine (1).

In an embodiment, the system (100) is configured to reduce NOx emissions from the hydrogen internal combustion engine (1) without having to always de-rate power output from the hydrogen internal combustion engine (1).

EQUIVALENTS

With respect to the use of substantially any plural and/or singular terms herein, those having skill in the art can translate from the plural to the singular and/or from the singular to the plural as is appropriate to the context and/or application. The various singular/plural permutations may be expressly set forth herein for sake of clarity.

It will be understood by those within the art that, in general, terms used herein, and especially in the appended claims (e.g., bodies of the appended claims) are generally intended as “open” terms (e.g., the term “including” should be interpreted as “including but not limited to,” the term “having” should be interpreted as “having at least,” the term “includes” should be interpreted as “includes but is not limited to,” etc.). It will be further understood by those within the art that if a specific number of an introduced claim recitation is intended, such an intent will be explicitly recited in the claim, and in the absence of such recitation no such intent is present. For example, as an aid to understanding, the following appended claims may contain usage of the introductory phrases “at least one” and “one or more” to introduce claim recitations. However, the use of such phrases should not be construed to imply that the introduction of a claim recitation by the indefinite articles “a” or “an” limits any particular claim containing such introduced claim recitation to inventions containing only one such recitation, even when the same claim includes the introductory phrases “one or more” or “at least one” and indefinite articles such as “a” or “an” (e.g., “a” and/or “an” should typically be interpreted to mean “at least one” or “one or more”); the same holds true for the use of definite articles used to introduce claim recitations. In addition, even if a specific number of an introduced claim recitation is explicitly recited, those skilled in the art will recognize that such recitation should typically be interpreted to mean at least the recited number (e.g., the bare recitation of “two recitations,” without other modifiers, typically means at least two recitations, or two or more recitations). Furthermore, in those instances where a convention analogous to “at least one of A, B, and C, etc.” is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., “a system (100) having at least one of A, B, and C” would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). In those instances where a convention analogous to “at least one of A, B, or C, etc.” is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., “a system (100) having at least one of A, B, or C” would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). It will be further understood by those within the art that virtually any disjunctive word and/or phrase presenting two or more alternative terms, whether in the description, claims, or drawings, should be understood to contemplate the possibilities of including one of the terms, either of the terms, or both terms. For example, the phrase “A or B” will be understood to include the possibilities of “A” or “B” or “A and B.”

In addition, where features or aspects of the disclosure are described in terms of Markush groups, those skilled in the art will recognize that the disclosure is also thereby described in terms of any individual member or subgroup of members of the Markush group.

While various aspects and embodiments have been disclosed herein, other aspects and embodiments will be apparent to those skilled in the art. The various aspects and embodiments disclosed herein are for purposes of illustration and are not intended to be limiting, with the true scope and spirit being indicated by the following claims.

Referral numerals:
Particulars
Numeral
Hydrogen internal combustion engine 1
Hydrogen injector 2
Water injection unit 3
EGR 10
ECU 4
NOx sensor 5
Pump 6
Water storage tank 7
Water level sensor 8
EGR valve 9
System 100
Method steps 301-304