Claims:We claim:

1. A system (100) to recover water from exhaust gas of a hydrogen Internal Combustion [IC] engine (1), the system (100) comprising:
a bypass conduit (2) in fluid communication with an exhaust tailpipe (9) of the hydrogen IC engine (1);
a bypass valve (3) disposed in the bypass conduit (2);
a separator (5) positioned in the bypass conduit (2), the separator (5) is configured to separate condensed water from the exhaust gas; and
an Electronic Control Unit (ECU) (10) of the vehicle operatively coupled to the bypass valve (3), wherein the ECU (10) is configured to selectively operate the bypass valve (3) based on level of water in a water reservoir (7) associated with the hydrogen IC engine (1) and temperature of the exhaust gas, to recover the water from the exhaust gas.

2. The system (100) as claimed in claim 1, comprises a pump (6) in fluid communication with the separator (5).

3. The system (100) as claimed in claim 2, wherein the pump (6) is communicatively coupled to the ECU (10) and the ECU (10) is configured to selectively operate the pump (6) to direct the recovered water to at least one of the water reservoir (7) and a combustion chamber of the hydrogen IC engine (1).

4. The system (100) as claimed in claim 3, wherein the pump (6) includes low-pressure pump (6) to direct the recovered water into the water reservoir (7) and high-pressure pump (8) to direct the recovered water into inlet of the combustion chamber of the engine.

5. The system (100) as claimed in claim 1, wherein the ECU (10) is configured to receive a signal corresponding to level of the water in the water reservoir (7) from a first sensor (11) associated with the water reservoir (7).

6. The system (100) as claimed in claim 1, wherein the ECU (10) is configured to receive a signal corresponding to temperature of the exhaust gas from a second sensor (12) associated with the exhaust tailpipe (9).

7. The system (100) as claimed in claim 1, wherein the ECU (10) is configured to operate the bypass valve (3) to an open position to direct the exhaust gas to the bypass conduit (2) when water level in the water reservoir (7) falls below a predetermined level and when the exhaust gas temperature is less than a predetermined value.

8. The system (100) as claimed in claim 1, wherein ECU (10) is configured to consider the progressive variation of the water level in the water reservoir drops and the temperature of the exhaust gas to operate the bypass valve (3) to the open position.

9. The system (100) as claimed in claim 8, wherein the ECU (10) is configured to considers the increase in temperature limit when the water level in the water reservoir is decreasing.

10. The system (100) as claimed in claim 1 comprises a pre-cooler (4) in fluid communication with the bypass conduit (2) to cool the exhaust gas before passing the exhaust gas to the separator (5).

11. The system (100) as claimed in claim 1, wherein the separator (5) is a mesh mist separator (5).

12. A method to recover water from exhaust gas of a hydrogen IC engine (1), the method comprising:
receiving, by an ECU (10) of the vehicle signals corresponding to level of water in the water reservoir (7) and temperature of exhaust gas in an exhaust tailpipe (9);
comparing, by the ECU (10), the level of water in the water reservoir (7) and the temperature of exhaust gas in the exhaust tailpipe (9) with a predetermined values; and
operating, by the ECU (10), a bypass valve (3) to selectively direct exhaust gas from the exhaust tailpipe (9) to a bypass conduit (2) based on the comparison;
wherein, the bypass conduit (2) is disponed in fluid communication with a separator (5) and the separator (5) is configured to separate condensed water from the exhaust gas.

13. The method as claimed in claim 12, wherein the ECU (10) receives a signal corresponding to the level of the water in the water reservoir (7) from a first sensor (11) associated with the water reservoir (7).

14. The method as claimed in claim 12, wherein the ECU (10) receives a signal corresponding to the temperature of the exhaust gas from a second sensor (12) associated with the exhaust tailpipe (9).

15. The method (100) as claimed in claim 12, wherein ECU (10) is configured to consider the progressive variation of the water level in the water reservoir drops and the temperature of the exhaust gas to operate the bypass valve (3) to the open position.

16. The method (100) as claimed in claim 12, wherein the ECU (10) is configured to considers the increase in temperature limit when the water level in the water reservoir is decreasing.

17. The method as claimed in claim 12, wherein the exhaust gas is cooled in a pre-cooler (4) before passing the exhaust gas to the separator (5).

18. The method as claimed in claim 12 comprises separating, by the ECU, a pump (6) selectively to pump the recovered water from the separator to at least one of the water reservoir (7) and a combustion chamber of the hydrogen IC engine (1).

19. The method as claimed in claim 18, wherein the pump (6) includes at least one of a low-pressure pump (6) to direct the recovered water into the water reservoir (7) and a high-pressure pump (8) to direct the recovered water into the inlet of the combustion chamber of the engine.

20. A vehicle comprising a system (100) as claimed in claim 1.

Dated this 17th December 2020

GOPINATH A S
IN/PA – 1852
OF K&S PARTNERS
AGENT OF THE APPLICANT(S)
, Description:FORM 2

THE PATENTS ACT 1970

[39 OF 1970]
&
THE PATENTS RULES, 2003

COMPLETE SPECIFICATION

[See section 10; rule 13]

TITLE: “A SYSTEM AND A METHOD FOR RECOVERING WATER FROM EXHAUST GAS OF HYDROGEN IC ENGINE”

Name and Address of the Applicant:
TATA MOTORS LIMITED; an Indian company having a registered address at Bombay
House, 24 Homi Mody Street, Hutatma Chowk, Mumbai 400 001 Maharashtra, India.

Nationality: Indian

And
TATA MOTORS EUROPEAN TECHNICAL CENTRE PLC, of 18 Grosvenor Place, London, SWIX 7HS, London, United Kingdom.
Nationality: United Kingdom

The following specification particularly describes the invention and the manner in which it is to be performed.

TECHNICAL FIELD

The present disclosure, in general, relates to the field of automobiles. Particularly, but not exclusively, the present disclosure relates to a hydrogen IC engine. Further, embodiments of the present disclosure relate to a system and a method for recovering water from exhaust gas of a hydrogen IC 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 includes nitrogen oxide, carbon dioxide, and water vapor traces after combustion.

Burnt gases of the exhaust from a hydrogen IC engine generally contains traces of water vapor, carbon dioxide and oxides of nitrogen. This mixture of gases is to be treated prior to being dispensed to the surroundings or atmosphere. In a hydrogen IC engine, water injection significantly affects the NOx emissions. The traces of water found in the exhaust gas has always been found to exceed the required volume of water for injection. Instances of using an exhaust gas water recovery system has been known. However, such recovery systems always tend to add up to the overall weight and bulkiness of the vehicle.

To overcome such situation, with advent of technology, various system and methods have been developed where water vapors from the exhaust gas can be carefully treated. However, such configurations tend to affect working of the IC engine during long run, as components involved therein tend to incorporate increased mechanical movements that may cause wear out and may require frequent servicing/replacement to maintain efficiency of the IC engine. Nonetheless, during operation of the vehicle under varying loaded conditions, composition of the water vapors in the exhaust may vary, thereby rendering the quantity of water vapor to 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 IC 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 system for recovering water from exhaust gas of a hydrogen IC engine is disclosed. The system includes a bypass conduit in fluid communication with an exhaust tailpipe of the hydrogen IC engine. A bypass valve disposed in the bypass conduit and a separator positioned in the bypass conduit, wherein the separator is configured to separate condensed water from the exhaust gas. Further, an Electronic Control Unit (ECU) of the vehicle operatively coupled to the bypass valve. The ECU is configured to selectively operate the bypass valve based on level of water in a water reservoir associated with the hydrogen IC engine and temperature of the exhaust gas, to recover the water from the exhaust gas.

In an embodiment, the system includes a pump in fluid communication with the separator. The pump is communicatively coupled to the ECU and the ECU is configured to selectively operate the pump to direct the recovered water to at least one of the water reservoir and a combustion chamber of the hydrogen IC engine. The pump is communicatively coupled to the ECU and the ECU is configured to selectively operate at least one of low-pressure pump to direct the recovered water into the water reservoir and high-pressure pump to direct the recovered water into the inlet of the combustion chamber of the engine.

In an embodiment, the ECU is configured to receive a signal corresponding to level of the water in the water reservoir from a first sensor associated with the water reservoir. The ECU is configured to receive a signal corresponding to temperature of the exhaust gas from a second sensor associated with the exhaust tailpipe. The ECU is configured to operate the bypass valve to an open position to direct the exhaust gas to the bypass conduit when water level in the water reservoir falls below a predetermined level and when the exhaust gas temperature is less than a predetermined value.

In an embodiment, the ECU is configured to consider the progressive variation of the water level in the water reservoir drops and the temperature of the exhaust gas to operate the bypass valve to the open position. The system the ECU is configured to considers the increase in temperature limit when the water level in the water reservoir is decreasing. The system includes a pre-cooler in fluid communication with the bypass conduit to cool the exhaust gas before passing the exhaust gas to the separator.

In another non-limiting embodiment, a method to recover water from exhaust gas of a hydrogen IC engine is disclosed. The method includes receiving, by an ECU of the vehicle signals corresponding to level of water in the water reservoir and temperature of exhaust gas in an exhaust tailpipe. The ECU compares the level of water in the water reservoir and the temperature of exhaust gas in the exhaust tailpipe with a predetermined value. The bypass valve is operated selectively by the ECU to direct exhaust gas from the exhaust tailpipe to a bypass conduit based on the comparison. The bypass conduit disponed in fluid communication with a separator and the (5) is configured to separate condensed water from the exhaust gas. Further, separating condensed water from exhaust gases, by a separator positioned in the bypass conduit.

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:

Fig. 1 illustrates a block diagram of a system for recovering water from exhaust gas of a hydrogen IC engine when the bypass valve is in closed condition, in accordance with an embodiment of the present disclosure.

Fig. 2 illustrates a block diagram of a system for recovering water from exhaust gas of a hydrogen IC engine when the bypass valve is in open condition, in accordance with an embodiment of the present disclosure.

Fig. 3 is a flow chart illustrating sequence of steps involved in a method for recovering water from exhaust tailpipe of the hydrogen IC engine, in accordance with an embodiment of the present disclosure.

Fig. 4 is a flowchart illustrating conditions for selective operation of a by-pass valve of the system of Fig .1.

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 recovering water from exhaust gas of a hydrogen IC engine. Hydrogen IC engine is an internal combustion engine run by hydrogen as fuel. The hydrogen IC engine is in fluid communication with a hydrogen injector, an exhaust gas recirculation [EGR] unit and a water injection unit. The system includes an exhaust gas temperature sensor, disposed in an exhaust system or exhaust tail pipe of the hydrogen IC engine, configured to generate a signal corresponding to temperature of exhaust gas in the exhaust emitted from the hydrogen IC engine. The system includes a water level sensor, disposed in the water reservoir of an exhaust gas water recovery system of the hydrogen IC engine, configured to generate a signal corresponding to level of water in the water reservoir. The system further includes an electronic control unit, communicatively coupled to the temperature sensor of, a water level sensor of water reservoir, a bypass valve, and a pump. The electronic control unit [ECU] is configured to determine temperature of exhaust gas emitted and water level in the water reservoir in the water recovery system of hydrogen IC engine, based on the signal from a temperature sensor and water level sensor, respectively. Upon determining the temperature and water level, the ECU is configured to control a bypass valve disposed in a bypass conduit. The ECU is further configured to control the bypass valve, to direct the exhaust gas emitted from the hydrogen IC engine into the exhaust water recovery system. Based on operation of the bypass valve, the exhaust gas is directed into the exhaust gas water recovery system. Thus, reducing the load on pre-cooler/condenser in water recovery system which allows smaller, less expensive components may be used. Further, the system and method reduces back pressure introduced by the water recovery system.

In an embodiment, the term “exhaust gas” refers to mixture of burnt gases that may be produced as a by-product of combustion in the hydrogen IC engine. The emissions may include, but may not be limited to, nitrogen oxides, water vapors, carbon dioxide, and other gases in negligible proportion that may be produced due to elements and/or compounds in the air.

In an embodiment, combustion in the hydrogen IC 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 to 4. 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 IC engine, where such vehicle may include, but not be limited to, light vehicles, passenger vehicles, commercial vehicles, and the like.

Fig. 1 is an exemplary embodiment of the present disclosure which illustrates a system (100) for recovering water from exhaust gas of a hydrogen IC engine (1) when the bypass valve is in closed condition. The system (100) includes a bypass conduit (2), a bypass valve (3), a pre-cooler (4), a separator (5), a pump (6), a water reservoir (7) and an optional high-pressure pump (8). The hydrogen IC engine (1) is configured to receive hydrogen in a gaseous form from a hydrogen injector (not shown in Figs), where the hydrogen is configured to act as a fuel for operation of the hydrogen IC 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 IC engine (1) via the hydrogen injector. The hydrogen injected into the hydrogen IC engine (1) may be 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 IC 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 IC engine (1).

Further, as the hydrogen and the air undergo combustion process in the hydrogen IC engine (1), thereby producing a mechanical power, heat energy is produced along with by-products including, but not limited to, carbon dioxide, NOx, water vapors and other gases in minimal composition. The carbon dioxide produced may be separately treated, NOx emissions in the exhaust is configured to be reduced and/or regulated, while traced quantity of water vapors in exhaust gases may be recovered by the system (100). To recover the water from the exhaust gas, a first sensor (11) may be provided in the water reservoir (7) of the hydrogen IC engine (1) to detect level of water present in the water reservoir (7). Further, a second sensor (11) may be disposed in an exhaust tailpipe (9) of the hydrogen IC engine (1) to detect temperature of exhaust gas. In addition, the system (100) may be positioned on the exhaust tailpipe (9) of the hydrogen IC engine (1). It may also be inherent that the system (100) can also be provided before the exhaust gas is channelized to the EGR (not shown in Figs) or may also be positioned anywhere along the EGR unit and before an inlet manifold of the hydrogen IC engine (1).

In the illustrative embodiment, the first and second sensors (11 and 12) may be communicatively coupled to an electronic control unit [hereafter also referred to as ECU (10)], where the first and sensors (11 and 12) are configured to detect level of water in the water reservoir and temperature of exhaust gas in exhaust tailpipe (9) respectively. Further, the sensors (11 and 12) are configured to generate a signal corresponding to the level of water and temperature of exhaust gas of the hydrogen IC engine (1). Based on the signal from the first and second sensors (11 and 12), the ECU (10) is configured to selectively operate the bypass valve (3) positioned in the bypass conduit (2), to suitably direct at least a portion of exhaust gas from the exhaust tailpipe (9) of the hydrogen IC engine (1).

Fig. 2 is an exemplary embodiment of the present disclosure which illustrates a system (100) for recovering water from exhaust gas of a hydrogen IC engine (1) when the bypass valve is in open condition. The water injection unit includes a pump (6, 8) fluidly connected to a water reservoir (7), associated with the vehicle. In an embodiment, the pump (6, 8) can be a water pump. The water pump (6, 8) may be communicatively coupled to the ECU (10) so that, based on an operational signal from the ECU (10), water from the water reservoir (7) may be selectively pumped to be injected into the hydrogen IC engine (1). Further, the ECU (10) may be configured to generate the operational signal to the pump (6, 8) upon determining quantity of water in the water reservoir (7). A first sensor (11) i.e.: water level sensor is configured to detect quantity or level of water in the water reservoir (7). Upon detecting the quantity or level of water, the water sensor is configured to transmit a signal to the ECU (10). Based on the signal from the first sensor (11), the ECU (10) is configured to compare the quantity of water in the water reservoir (7) with a predetermined value stored in a memory unit [not shown in Figs] associated with the ECU (10). The ECU (10) is configured to generate the operational signal to the pump (6, 8) when the determined quantity of water in the water reservoir (7) is at least at the predetermined limit, while when the operational signal is not transmitted to the pump (6, 8) by the ECU (10), when the determined quantity of water in the water reservoir (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 reservoir (7). Due to requirement of minimum quantity of water in the water reservoir (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 reservoir (7) is at least at the predetermined limit, a predefined quantity of water may be selectively injected into the hydrogen IC 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 IC engine (1) after an expansion stroke, and the like may be produced. Furthermore, as knocking in the hydrogen IC engine (1) is averted, requirement of controlling quantity of hydrogen being injected through the hydrogen injector may be prevented. In addition, as the water injected into the hydrogen IC 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 IC engine (1) when the NOx emissions exceeds the predefined limit. In an embodiment, the water injection unit is at least one of but not limited to a spray mechanism, a nozzle, an atomizer, and any other component that may impinge and disperse water into the hydrogen IC engine (1).

Further referring to Fig. 2, the bypass valve (3) may be at least one of but not limited to a simple actuatable butterfly valve, globe valve, rotary valve, ball valve, or a solenoid actuated valve. A control strategy (as further best described in further Figs) is implemented through an ECU (10) to control the actuation of the bypass valve (3). In an embodiment, when the valve is 100% closed, flow is blocked to the water recovery system (200) and all exhaust gas flows to atmosphere (as represented by the path shown by flow arrows). At 100% open, the exhaust gas is distributed between the water recovery system (200) and the exhaust tailpipe (9) based on back pressure. The pre-cooler (4) is further configured to reduce the directed exhaust gas temperature down to an acceptable level. In some embodiment, the pre-cooler (4) consists of two flaps in the sidewall of the bypass conduit (2) that can be opened to allow ambient air to be drawn into the exhaust gas stream by venturi effect. In an embodiment, when the cooler ambient air is mixed with hot exhaust gas, the temperature of exhaust gas falls to an acceptable level before condensation. The cooled exhaust gases then pass through the separator (5), wherein the separator (5) is at least one of but not limited to a mesh mist separator which condenses and separates the water vapor from the exhaust gases passively. In some embodiment, the mesh mist separator (5) consists of a mat or bundle of wire fibers that creates an intricate path to the large surface area droplets entrained in the exhaust gas stream. Further, water vapor separation from the stream of mixture of exhaust gases is achieved by impingement on, and capture by, the filaments of the mesh where the condensed droplets amalgamate and drain. The remaining exhaust gas continues through the filter material provided in the separator and is discharged to the atmosphere. In an embodiment, a pipe is provided at the bottom of the separator (5) which directs the recovered water (condensed droplets) to a high-pressure pump (6) which pumps the water ready for injection, or to a low-pressure pump which pumps water to a water reservoir (7) and then to a high-pressure pump (8) upstream of the water reservoir (7) for injecting water into the hydrogen IC engine (1). Due to the high concentration of water in hydrogen IC engine (1) exhaust gases, there will be enough flow through the water recovery system (200) to recover the required amount of water for injection into the hydrogen IC engine (1).

In an embodiment, the at least one bypass valve (3) may be operable between an open condition and a closed condition on receiving the operational signal from the ECU (10). The ECU (10) may be configured to operate the at least one bypass valve (3) to a closed condition, when at least one of exhaust gas temperature in the exhaust tailpipe exceeds the predefined value and quantity of water in the water reservoir (7) is lower than the predetermined limit. With such configuration, the ECU (10) may be configured to selectively operate the bypass valve (3) based on signals received from the first sensor (11) and the second sensor (12), whereby regulating the recovery of water in the hydrogen IC engine (1). In an embodiment, the first sensor (11) 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 reservoir (7). In an embodiment, the second sensor (12) may be including, but not limited to, a thermocouple, RTDs, thermistors, and any other temperature sensitive sensor that may be configured to determine the temperature of exhaust gas in the exhaust tailpipe (9).

In an embodiment, the water pump (6, 8) may be a positive displacement pump (6, 8), which may be based on factors including but not limited to, configuration in which power is supplied to the water pump (6, 8) [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 some embodiments, the ECU (10) may be a centralized control unit of the vehicle or may be a dedicated control unit to the system (100) associated with the centralized control unit of the vehicle. The ECU (10) may also be associated with other control units including, but not limited to, body control unit, engine control unit, and the like. The ECU (10) 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 (10) 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 Fig. 3 which is an exemplary embodiment of the present disclosure illustrating a flow chart of a method for recovering water from exhaust gas of the hydrogen IC engine (1). In an embodiment, the method may be implemented in any vehicle including, but not limited to, motorcycles, passenger vehicles, commercial vehicles, and the like, which may be operable by hydrogen IC 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 (10) is configured to determine the water level of water through the signals from the first sensor (11) disposed in the water reservoir (7) and to determine the temperature of exhaust gas from the hydrogen IC engine (1) through the signals from the second sensor (12) disposed in the exhaust tailpipe (9).

At block 302, the ECU (10) is configured to compare the water level in the water reservoir and temperature of the exhaust gas from the exhaust tailpipe by the first and second sensors (11 and 12) with the predefined values stored in the memory unit associated with the ECU (10). When the water level in the water reservoir falls below a predetermined valve and the temperature of exhaust gas is within the predefined limits, the ECU (10) is configured to selectively operate at least one of the bypass valve (3).

At block 303, the ECU (10) is configured to operate a bypass valve (3), wherein the quantity of the exhaust gas being directed into the exhaust gas water recovery system of the hydrogen IC engine (1) may be controlled by the at least one bypass valve (3). The ECU (10) is configured to control at least one bypass valve (3) by generating the operating signal based on at least one of exhaust gas temperature and the level of water in the water reservoir (7). The at least one bypass valve (3) may be operated between the open condition and the closed condition by the ECU (10). For example, when temperature of exhaust gas is less than the predefined value and the level of water in the water reservoir (7) is greater than the predetermined limit, then the bypass valve (3) is operated to the open condition by the ECU (10) for directing the exhaust gas into the bypass conduit (2). Also, when temperature of exhaust gas is more than the predefined value and the level of water in the water reservoir (7) is less than the predetermined limit, then the bypass valve (3) is operated to the closed condition by the ECU (10) for restricting the flow of the exhaust gas into the bypass conduit (2). In an embodiment, when the level of water in the water reservoir (7) is below the predetermined limit, then the ECU (10) 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.

At block 304, the separator (5) is configured to separate the condensed water from the exhaust gases. A pipe is provided at the bottom of the separator (5) which directs the recovered water (condensed droplets) to a high-pressure pump (6) which pumps the water ready for injection, or to a low-pressure pump which pumps water to a water reservoir (7) and then to a high-pressure pump (8) upstream of the water reservoir (7) for injecting water into the hydrogen IC engine (1).

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

Now referring to Fig. 4 which is an exemplary embodiment of the present disclosure which illustrates a control strategy for a bypass valve (3) of a system for recovering water from exhaust gas of a hydrogen IC engine (1). Water injection significantly improves NOx emissions in a hydrogen IC engine (HICE) whilst maintaining power output. An exhaust gas water recovery system cools and condenses water vapor in the exhaust gases and feeds the water to a reservoir for injection into the combustion chamber. A HICE has some differences when compared to a conventional fuel IC engine: the volume of water in the exhaust gases is considerably more than other hydrocarbon fuels and more importantly is more than is needed for water injection. The exhaust gas temperature varies considerably with operating condition of the engine because of the lean mixture for low and part loads.

The strategy works by operating the bypass valve (3) based on the exhaust gas temperature and water level in water reservoir (7). As the water level in the water reservoir (7) drops, water is permitted to be recovered at a higher exhaust gas temperature. However, as the water level in the water reservoir (7) increases, the exhaust gas temperature limit which allows water recovery reduces.

In an exemplary embodiment, when the ignition of the hydrogen IC engine (1) is turned ”ON”, the ECU (10) receives signals from the first sensor (11). Once the level of water in the water reservoir (7) is determined and if the water level is above 70%, the ECU (10) is configured to keep the bypass valve (3) closed. In an embodiment, if the water level goes less than a threshold value for example 50%, the ECU (10) is configured to start the water recovery operation. To start the recovery operation, the ECU receives the exhaust gas temperature in exhaust tailpipe (9) using a second sensor (12). If the exhaust gas temperature is below 250°C, the ECU (10) is configured to operate the bypass valve (3) to an open position and water is recovered from the exhaust gases. In an embodiment, if the water level is around 40%, the ECU (10) is configured to receive the exhaust gas temperature in exhaust tailpipe (9) using a second sensor (12). If the exhaust gas temperature is below 300°C, the ECU (10) is configured to operate the bypass valve to an open position and water is recovered from the exhaust gases. In an embodiment, if the water level is above 30%, the ECU (10) is configured to receive the exhaust gas temperature in exhaust tailpipe (9) using a second sensor (12). If the exhaust gas temperature is below 400°C, the ECU (10) is configured to operate the bypass valve to an open position and water is recovered from the exhaust gases. In an embodiment, if the water level is below 20%, the ECU (10) is configured to operate the bypass valve (3) to an open position and water is recovered from the exhaust gases. With this strategy, the system (100) may be operated to recover the water from the exhaust gas only in the required instances, and thereby avoid unnecessary recovery cycles.

Further, the bypass valve (3) may also be controlled to be partially open at certain conditions to reduce backpressure and improve transient response which would require higher calibrations. In an embodiment, the temperature of exhaust gas and water level of water reservoir (7) at which the bypass valve (3) is operated varies with respect to the specification of the hydrogen IC engine. However, the general strategy based on current water level in water reservoir (7) and exhaust gas temperature in exhaust tailpipe would remain the same. Also, in heavy transient conditions the exhaust temperature may fluctuate between low and high temperatures perhaps causing instability with the control system. The ECU (10) is configured to implement a pre-check that predicts a transient event and blocks the control logic until the event is over, or a check that only initiates the control strategy when steady state engine operation is recognized.

Advantageously, the method optimises when the water recovery system is active by controlling a bypass valve (3) based on the exhaust gas temperature and water level of reservoir.

In an embodiment, the method brings benefits such as reduces load on pre-cooler or condenser in water recovery system which allows smaller, less expensive components to be used, reduces back pressure introduced by the water recovery system, and maintains water level for water injection system.

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 IC engine 1
Bypass conduit 2
Bypass valve 3
Pre-cooler 4
Separator 5
Low- or high-pressure pump 6
Water reservoir 7
High-Pressure pump 8
Exhaust Tailpipe 9
ECU 10
First Sensor 11
Second Sensor 12

System 100
Method steps 301-304