DESC:FORM 2
The Patent Act 1970
(39 of 1970)
&
The Patent Rules, 2005

COMPLETE SPECIFICATION
(SEE SECTION 10 AND RULE 13)

TITLE OF THE INVENTION

“DETECTING AND RESPONDING TO BACKFLOW OF AIR/AIR-FUEL MIXTURE IN HYDROGEN FUELED ENGINE”

APPLICANT:

Name Nationality Address
Mahindra & Mahindra Limited Indian Mahindra & Mahindra Ltd.,
MRV, Mahindra World City (MWC),
Plot No. 41/1, Anjur Post, Chengalpattu,
Kanchipuram District – 603204 (TN) INDIA

The following specification particularly describes and ascertains the nature of this invention and the manner in which it is to be performed:-

TECHNICAL FIELD
[001] The embodiments herein generally relate to gaseous fueled internal combustion engines and more particularly but not exclusively to hydrogen fueled internal combustion engines.

BACKGROUND
[002] Owing to rapid depletion of conventional fuels, alternative fuels have gained prominence. Hydrogen is one of the alternative fuels that are currently being implemented in vehicles. Though hydrogen is abundant and burns free without carbon emissions, vehicles operating with hydrogen fueled engines require excessive safety systems than conventional gasoline or other gaseous fueled engines.
[003] Pre-ignition is a major problem in hydrogen fuelled engines because of hydrogen’s lower ignition energy, wider flammability range and shorter quenching distance. Pre-ignition occurs when the air-fuel mixture in the combustion chamber of the engine ignite before normal ignition resulting in inefficient combustion and rough running. Sources for pre ignition are hot gases in the combustion chamber and hot spots in the combustion chamber and exhaust valve. When pre-ignition occurs near the intake valve then the flame may travel back into the intake manifold resulting in backfire. Valve overlap between the opening of the intake and exhaust valve may also result in backfire due to mixing of hot exhaust gases with fresh air-fuel mixture.
[004] Backfire is the uncontrolled combustion that takes place in the intake manifold causing the reverse flow of intake air or air fuel mixture which results in the damage of turbo charger, throttle valve and other intake system components creating unpleasant noise and poses a safety hazard for the passengers in the vehicle having the hydrogen fueled engine.
[005] Therefore, there exists a need for a system and a method for detecting and responding to backflow of air/air-fuel mixture in hydrogen or similar gas fueled engine. Furthermore, there exists a need for a system and a method that can eliminate the aforementioned drawbacks.

OBJECTS
[006] The principal object of an embodiment of this invention is to provide a system and a method for detecting and responding to backflow of air/air-fuel mixture in hydrogen or similar gas fueled engine.
[007] Another object of an embodiment of this invention is to provide a system and method that protects intake system components of a hydrogen or similar gas fueled engine.
[008] Another object of an embodiment of this invention is to provide a system and a method that improves safety level of a vehicle having hydrogen or similar gas fueled engine.
[009] Yet, another object of an embodiment of this invention is to provide a gas fueled engine having a system for detecting and responding to backflow of air/air-fuel mixture in the engine.
[0010] The objects of the embodiments herein will be better appreciated and understood when considered in conjunction with the following description and the accompanying drawings. It should be understood, however, that the following descriptions, while indicating embodiments and numerous specific details thereof, are given by way of illustration and not of limitation. Many changes and modifications may be made within the scope of the embodiments herein without departing from the spirit thereof, and the embodiments herein include all such modifications.

BRIEF DESCRIPTION OF DRAWINGS
[0011] This invention is illustrated in the accompanying drawings, throughout which like reference letters indicate corresponding parts in the various figures. The embodiments herein will be better understood from the following description with reference to the drawings, in which:
[0012] FIG. 1 depicts a schematic of the system in conjunction with an engine according to an embodiment of the invention as disclosed herein; and
[0013] FIG. 2 depicts a flow chart of the method according to an embodiment of the invention as disclosed herein.

DETAILED DESCRIPTION
[0014] The embodiments herein and the various features and advantageous details thereof are explained more fully with reference to the non-limiting embodiments that are illustrated in the accompanying drawings and detailed in the following description. Descriptions of well-known components and processing techniques are omitted so as to not unnecessarily obscure the embodiments herein. The examples used herein are intended merely to facilitate an understanding of ways in which the embodiments herein may be practiced and to further enable those of skill in the art to practice the embodiments herein. Accordingly, the examples should not be construed as limiting the scope of the embodiments herein.
[0015] The embodiments herein achieve a system and a method for detecting and responding to backflow of air/air-fuel mixture in hydrogen or similar gas fueled engine. Referring now to the drawings, and more particularly to FIGS. 1 through 2, where similar reference characters denote corresponding features consistently throughout the figures, there are shown embodiments.
[0016] FIG. 1 depicts a schematic of the system in conjunction with an engine according to an embodiment of the invention as disclosed herein. In an embodiment the system 100 includes a sensor 102, a control valve 104, and a control unit 106. In an embodiment the engine 200 includes a combustion chamber 202, an air intake unit 204, a turbocharger 206, a throttle valve 208, an intake manifold 210, a fuel injection system 212, an ignition system 214 and a means (not shown) controlling the throttle valve 208. However, it is also within the scope of the invention for the engine 200 to exclude any of the aforementioned components or include any other components without otherwise deterring the intended function of the engine 200. In an embodiment the engine 200 is a hydrogen fueled engine. However, it is also within the scope of the invention to provide the system 100 for any gas fueled engine.
[0017] In an embodiment the means (not shown) controlling the throttle valve 208 is a throttle pedal. However, it is also within the scope of the invention to provide a throttle grip or any other means for controlling the throttle valve 208. The means (not shown) controlling the throttle valve 208, controls the throttle valve 208 to control the flow rate of air entering the throttle valve 208 to vary the speed or power of the engine 200.
[0018] In an embodiment the engine 200 includes a turbocharger 206. However, it is also within the scope of the invention to provide the engine 200 with a supercharger or electric compressor or any device for compressing intake air. Further, it is also within the scope of the invention to provide the engine 200 without the turbocharger 206 or supercharger or electric compressor or any device for compressing the intake air.
[0019] In an embodiment the engine 200 has a port type fuel injection system 212. However, it is also within the scope of the invention to provide the engine 200 with a direct fuel injection system or any other type of fuel injection system.
[0020] In an embodiment the sensor 102 is used for sensing or providing information about the position of the means (not shown) controlling the throttle valve 208 to the control unit 106. The sensor 102 is operatively connected to the means (not shown) controlling the throttle valve 208 and the sensor 102 is provided in communication with the control unit 106. In an embodiment the sensor 102 is a throttle pedal position sensor.
[0021] In an embodiment the control valve 104 is used for controlling the flow rate of backflow air or air-fuel mixture from the throttle valve 208 to the air intake unit 204. The control valve 104 is provided in fluid communication with the throttle valve 208 and the air intake unit 204. The control valve 104 is provided in communication with the control unit 106.
[0022] In an embodiment the control unit 106 is used for detecting the backflow of air or air-fuel mixture in the engine 200 and for controlling the control valve 104. The control unit 106 detects the backflow of air or air-fuel mixture by determining the tip-out of the means (not shown) controlling the throttle valve 208 based on the information provided by the sensor 102 and controls the control valve 104 based on the tip-out rate of the means (not shown) controlling the throttle valve 208. Tip-out is the release or disengagement of the means (not shown) controlling the throttle valve 208 by the user or operator which results in closure of throttle valve 208 and the tip-out rate or rate of tip-out is the rate at which the tip-out occurs. Based on the tip-out rate of the means (not shown) controlling the throttle valve 208, the control unit 106 provides signal to open the control valve 104 for a predetermined amount of time for facilitating the flow of backflow air or air-fuel mixture from the throttle valve 208 to the air intake unit 204.
[0023] In an embodiment, the control unit 106 described herein can include for example, but not limited to, microprocessor, microcontroller, controller, smart phone, portable electronic device, communicator, tablet, laptop, computer, consumer electronic device, a combination thereof, or any other device capable of processing signals.
[0024] The working of the system 100 is as follows. FIG. 1 depicts a schematic of the system in conjunction with an engine according to an embodiment of the invention as disclosed herein. In fig.1 the long dash depicts the flow of information between the components of the system 100 and the short dash represents the flow of backflow air/air-fuel mixture. During the operation of the engine 200, the atmospheric air first enters the air intake unit 204. The air intake unit 204 is used for filtering the incoming air from dust and other particulate matters. Thereafter, the filtered air enters the turbocharger 206 and the turbocharger 206 compresses the filtered air. The compressed air from the turbocharger 206 enters the throttle valve 208. The air from the throttle valve 208enters the intake manifold 210. The throttle valve 208 is controlled by the means (not shown) controlling the throttle valve 208 to control the air supplied to the intake manifold 210. Thereafter, the fuel injection system 212 injects the fuel in the intake manifold 210 and the air-fuel mixture from the intake manifold 210 enters the combustion chamber 202. The air-fuel mixture in the combustion chamber 202 is ignited by the ignition system 214 and the combustion of air-fuel mixture takes place and the engine 200 generates power. Due to backfire or due to sudden closure of the throttle valve 208 the air or air fuel mixture from the intake manifold 210 backflows to the throttle valve 208 and turbocharger 206. The control unit 106 detects the backflow of air or air-fuel mixture by determining the tip-out of the means (not shown) controlling the throttle valve 208 based on the information provided by the sensor 102. Based on the tip-out rate determined, the control unit 106 controls the control valve 104 to open for a predetermined amount of time during which the backflow air or air-fuel mixture from the throttle valve 208 flows to the air intake unit 204, thereby the backflow air/air-fuel mixture is circulated to the engine 200.
[0025] The method 300 for detecting and responding to backflow of air/air-fuel mixture in a gas fueled engine includes, detecting the backflow of air/air-fuel mixture in the engine by determining a tip-out of a means (not shown) controlling a throttle valve of the engine step 301 and circulating the backflow air/air-fuel mixture from the throttle valve of the engine to an air intake unit of the engine based on the tip-out rate of the means (not shown) controlling the throttle valve step 302.
[0026] The various actions, units, steps, blocks, or acts described in the method 300 can be performed in the order presented, in a different order, simultaneously, or a combination thereof. Further, in some embodiments, some of the actions, units, steps, blocks, or acts listed in the FIG. 2 may be omitted, added, skipped, or modified without departing from the scope of the invention.
[0027] The foregoing description of the specific embodiments will so fully reveal the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments herein have been described in terms of preferred embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modification within the spirit and scope of the embodiments as described herein.
CLAIMS
We claim
1. A system for detecting and responding to backflow of air/air-fuel mixture in a gas fueled engine, said system comprising:
a sensor adapted for sensing a position of a means controlling a throttle valve of the engine;
a control valve adapted for controlling a flow rate of the backflow air/air-fuel mixture from the throttle valve of the engine to an air intake unit of the engine, the control valve provided in fluid communication with the throttle valve and the air intake unit; and
a control unit adapted for detecting the backflow of air/air-fuel mixture in the engine and for controlling the control valve, the control unit provided in communication with the sensor and the control valve,
wherein
the control unit detects the backflow of air/air-fuel mixture in the engine by determining a tip-out of the means controlling the throttle valve based on an information provided by the sensor and controls the control valve to open for a predetermined amount of time based on the tip-out rate of the means controlling the throttle valve for facilitating the flow of backflow air/air-fuel mixture from the throttle valve to the air intake unit.
2. The system as claimed in claim 1, wherein said engine is a hydrogen fueled engine.
3. The system as claimed in claim 1, wherein said sensor is a throttle pedal position sensor.
4. The system as claimed in claim 1, wherein said means controlling the throttle valve is a throttle pedal.
5. The system as claimed in claim 1, wherein said means controlling the throttle valve is a throttle grip.
6. A method for detecting and responding to backflow of air/air-fuel mixture in a gas fueled engine, said method comprising:
detecting the backflow of air/air-fuel mixture in the engine by determining a tip-out of a means controlling a throttle valve of the engine; and
circulating the backflow air/air-fuel mixture from a throttle valve of the engine to an air intake unit of the engine based on the tip-out rate of the means controlling the throttle valve.
7. A gas fueled engine comprising:
a sensor adapted for sensing a position of a means controlling a throttle valve of the engine;
a control valve adapted for controlling a flow rate of the backflow air/air-fuel mixture from the throttle valve of the engine to an air intake unit of the engine, the control valve provided in fluid communication with the throttle valve and the air intake unit; and
a control unit adapted for detecting the backflow of air/air-fuel mixture in the engine and for controlling the control valve, the control unit provided in communication with the sensor and the control valve,
wherein
the control unit detects the backflow of air/air-fuel mixture in the engine by determining a tip-out of the means controlling the throttle valve based on an information provided by the sensor and controls the control valve to open for a predetermined amount of time based on the tip-out rate of the means controlling the throttle valve for facilitating the flow of backflow air/air-fuel mixture from the throttle valve to the air intake unit.
8. The gas fueled engine as claimed in claim 7 is a hydrogen fueled engine.
9. The gas fueled engine as claimed in claim 7, wherein said sensor is a throttle pedal position sensor.
10. The gas fueled engine as claimed in claim 7, wherein said means controlling the throttle valve is a throttle pedal.
11. The gas fueled engine as claimed in claim 7, wherein said means controlling the throttle valve is a throttle grip.

Dated this 4th January 2016

Signatures:

Name of the Signatory: Dr. Kalyan Chakravarthy

ABSTRACT
Detecting and responding to backflow of air/air-fuel mixture in hydrogen fueled engine includes a sensor, a control valve and a control unit. The control unit detects the backflow of air/air-fuel mixture in the engine by determining a tip-out of the means controlling the throttle valve of the engine based on an information provided by the sensor and controls the control valve to open for a predetermined amount of time based on the tip-out rate of the means controlling the throttle valve for facilitating the flow of backflow air/air-fuel mixture from the throttle valve to the air intake unit.

,CLAIMS:CLAIMS
We claim
1. A system for detecting and responding to backflow of air/air-fuel mixture in a gas fueled engine, said system comprising:
a sensor adapted for sensing a position of a means controlling a throttle valve of the engine;
a control valve adapted for controlling a flow rate of the backflow air/air-fuel mixture from the throttle valve of the engine to an air intake unit of the engine, the control valve provided in fluid communication with the throttle valve and the air intake unit; and
a control unit adapted for detecting the backflow of air/air-fuel mixture in the engine and for controlling the control valve, the control unit provided in communication with the sensor and the control valve,
wherein
the control unit detects the backflow of air/air-fuel mixture in the engine by determining a tip-out of the means controlling the throttle valve based on an information provided by the sensor and controls the control valve to open for a predetermined amount of time based on the tip-out rate of the means controlling the throttle valve for facilitating the flow of backflow air/air-fuel mixture from the throttle valve to the air intake unit.
2. The system as claimed in claim 1, wherein said engine is a hydrogen fueled engine.
3. The system as claimed in claim 1, wherein said sensor is a throttle pedal position sensor.
4. The system as claimed in claim 1, wherein said means controlling the throttle valve is a throttle pedal.
5. The system as claimed in claim 1, wherein said means controlling the throttle valve is a throttle grip.
6. A method for detecting and responding to backflow of air/air-fuel mixture in a gas fueled engine, said method comprising:
detecting the backflow of air/air-fuel mixture in the engine by determining a tip-out of a means controlling a throttle valve of the engine; and
circulating the backflow air/air-fuel mixture from a throttle valve of the engine to an air intake unit of the engine based on the tip-out rate of the means controlling the throttle valve.
7. A gas fueled engine comprising:
a sensor adapted for sensing a position of a means controlling a throttle valve of the engine;
a control valve adapted for controlling a flow rate of the backflow air/air-fuel mixture from the throttle valve of the engine to an air intake unit of the engine, the control valve provided in fluid communication with the throttle valve and the air intake unit; and
a control unit adapted for detecting the backflow of air/air-fuel mixture in the engine and for controlling the control valve, the control unit provided in communication with the sensor and the control valve,
wherein
the control unit detects the backflow of air/air-fuel mixture in the engine by determining a tip-out of the means controlling the throttle valve based on an information provided by the sensor and controls the control valve to open for a predetermined amount of time based on the tip-out rate of the means controlling the throttle valve for facilitating the flow of backflow air/air-fuel mixture from the throttle valve to the air intake unit.
8. The gas fueled engine as claimed in claim 7 is a hydrogen fueled engine.
9. The gas fueled engine as claimed in claim 7, wherein said sensor is a throttle pedal position sensor.
10. The gas fueled engine as claimed in claim 7, wherein said means controlling the throttle valve is a throttle pedal.
11. The gas fueled engine as claimed in claim 7, wherein said means controlling the throttle valve is a throttle grip.