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

“Safety system for gas powered vehicles”

APPLICANTS:

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 safety systems in vehicles, and more particularly to a safety system and method for gas powered vehicles.

BACKGROUND
[002] Growing concern on emissions and increase in the cost of petroleum products has put enormous pressure to find alternative sources of energy. Therefore attention is focused in finding out suitable alternative fuels as substitute for fossil fuels. Vehicles can use various forms of gas as fuel, such as Hydrogen, LPG (Liquefied Petroleum Gas), CNG (Compressed Natural Gas), biogas, and so on. However, these gases need not be stable and can be inflammable.
[003] Considering the example of hydrogen, which is a non-carbon fuel. However the combustion of hydrogen is fundamentally different from the combustion of hydrocarbon fuels. Hydrogen has a wider flammability li mit of 4–75% by volume in air compared to diesel or gasoline. The minimum energy required for ignition of hydrogen–air mixture is 0.02 mJ only. This enables hydrogen engine to run well on lean mixtures and ensures prompt ignition. its ease of leakage, low-energy ignition, wide range of combustible fuel-air mixtures, and its ability to embrittlement, which must be accounted for to ensure safe operation. Hydrogen combustion also causes pre-ignition and flashback. Pre-ignition is a major problem in hydrogen-fueled engines. If pre-ignition occurs nearer to the intake valve, then the flame may travel back into the induction system resulting in backfire.
[004] However, this creates the problems of premature ignition and flashback due to hot spots present in the cylinder that can serve as a source of ignition. Also Hydrogen fuel is lighter compared to air and possibility of leakage is higher and it requires sophisticated control system to avoid any kind of accident in vehicle.
[005] In general for all hydrogen vehicles hydrogen leakage detector are provided which will send signal to ECU if the leakage is detected on that particular point location. However, there are several other ways the leakage might cause accident or potential explosion of cylinders.

OBJECT
[006] The principal object of this invention is to provide a system for ensuring safety in gas powered vehicles, by preventing and minimizing line leakages, fires and/or explosions in cases of accidents, prevention of backfire and so on.

BRIEF DESCRIPTION OF FIGURES
[007] This invention is illustrated in the accompanying drawings, through out 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:
[008] FIG. 1 depicts a system for filling gas into a vehicle, according to embodiments as disclosed herein;
[009] FIG. 2 depicts the fuel supply system of a gas powered vehicle, according to embodiments as disclosed herein;
[0010] FIG. 3 depicts an internal valve, according to embodiments as disclosed herein;
[0011] FIG. 4 depicts a gas powered vehicle system, according to embodiments as disclosed herein;
[0012] FIG. 5 depicts an example scenario of a leakage in the high pressure line, according to embodiments as disclosed herein;
[0013] FIG. 6 depicts an example scenario of a leakage in the low pressure line, according to embodiments as disclosed herein;
[0014] FIG. 7 depicts an example scenario where the vehicle is in an accident, according to embodiments as disclosed herein; and
[0015] FIG. 8 depicts an example scenario when a fire and/or an explosion occur in or in the vicinity of the vehicle, according to embodiments as disclosed herein.

DETAILED DESCRIPTION
[0016] 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.
[0017] The embodiments herein disclose a system for ensuring safety in gas powered vehicles, by preventing and minimizing line leakages, fires and/or explosions in cases of accidents, prevention of backfire and so on. Referring now to the drawings, and more particularly to FIGS. 1 through 8, where similar reference characters denote corresponding features consistently throughout the figures, there are shown preferred embodiments.
[0018] The term ‘gas’ as used herein can be at least one of hydrogen, LPG (Liquefied Petroleum Gas), CNG (Compressed Natural Gas), biogas, and so on.
[0019] The term ‘vehicle’ as used herein can be at least one of a scooter, a motorcycle, a car, a van, a truck, a bus, a train, or any other vehicle configured to run on an engine using gas for providing energy.
[0020] FIG. 1 depicts a system for filling gas into a vehicle. FIG.1 depicts a cylinder 101 configured to contain the gas being filled into the vehicle. A receptacle 102 is provided as a means for interfacing with an external entity such as a gas pump nozzle, wherein gas can be pumped into the vehicle using the receptacle. A pressure gauge 103 can monitor the pressure of the gas during the filling, wherein the pressure gauge 103 can be present in or in the vicinity of the inlet line. In an embodiment herein, the vehicle can comprise of an on-board generator, which can generate the gas (such as hydrogen). In an embodiment herein, the pressure gauge 103 on sensing that the pressure in the inlet line is beyond a pre-defined range (either below or above the range), can take at least one action such as stopping the fuelling process, providing an alert to the driver of the vehicle and/or the person filling fuel in the vehicle. The gas then passes through a first non-return valve 104. The non-return valve 104 enforces the unidirectional flow of the gas; i.e., the gas only flows from the receptacle 102 to the cylinder 101 and not in the reverse direction. The gas passes through an internal valve 105, before being stored in the cylinder 101.
[0021] The internal valve 105 can be located internal to the cylinder 101, on the surface of the cylinder 101, or in the immediate vicinity of the cylinder 101. The internal valve 105 does not permit the gas in the cylinder 101 to flow out, unless actuated by an external entity (such as the ECU (Engine Control Unit) of the vehicle, or any other equivalent means). In an embodiment herein, the internal valve 105 can be a normally closed electrically driven gas valve. In an embodiment herein, the internal valve 105 can be a normally closed mechanically driven gas valve. The internal valve 105 can only remain open while the internal valve 105 is provided with electrical power. If the power is cut to the internal valve 105, the valve 105 will automatically close and prevent further flow of gas. In an embodiment herein, the internal valve 105 can comprise of means for measuring the temperature and pressure of the cylinder. In an embodiment herein, the internal valve 105 can comprise of a pressure/temperature or pressure & temperature release means.
[0022] The cylinder 101 can be at least one of a compressed storage tank, a cryogenic storage tank, and so on. The cylinder 101 can be connected to at least one pressure valve 106, wherein the pressure valve 106 can detect leakage of gas from the cylinder 101. The pressure valve 106 on sensing that the pressure in the cylinder 101 is beyond a pre-defined range (either below or above the range) or the pressure is changing at a rate greater than normal (for example, when the vehicle is running, the rate of fall in the pressure in the cylinder 101 is greater than the expected/predicted consumption of the vehicle), can take at least one action such as cutting the supply of gas, providing an alert to the driver of the vehicle and so on.
[0023] In an embodiment herein, the cylinder 101 need not be present in the case of a hydrogen powered vehicle. An onboard hydrogen generator can generate hydrogen and through the internal valve 105 to the above disclosed system.
[0024] FIG. 2 depicts the fuel supply system of a gas powered vehicle. The cylinder 101 is connected to a vent line 201 through a non-return valve 202. The non-return valve 202 can help prevent the reverse flow of hydrogen from the vent line 201, in case of a backfire.
[0025] In an embodiment herein, the non-return valve 202 can be a large surface area flashback arrestor of a suitable material (such as stainless steel). The non-return valve 202 can extinguish any dangerous flashback in any direction. The non-return valve 202 further comprises of a temperature sensitive cut-off valve, which can extinguish sustained flashbacks long before the internal temperature of the non-return valve 202 reaches a dangerous level. The non-return valve 202 can comprise of a spring loaded non-return valve, that prevents slow or sudden reverse gas flow forming explosive mixtures in the gas supply. The non-return valve 202 can comprise of a filter at the gas inlet that protects the non-return valve 202 against dirt contamination.
[0026] On receiving instructions from the ECU, the internal valve 105 can open and enable flow of gas from the cylinder 101 to the engine of the vehicle.
[0027] The gas flows through a non-return valve 203. The non-return valve 203 enables the flow of gas to be cut manually by a user of the vehicle. For example, in the case of an emergency, the user can cut the flow of the gas. In another example, when the vehicle is being serviced, the flow of gas can be cut off using the non-return valve 203. In an embodiment herein, excess gas can then pass through an excess flow valve. The excess flow valve can prevent the excess flow of gas beyond a set threshold, hereby preventing the rapid dispersion of the gas (even in case such as a leakage in high pressure line, and so on).
[0028] The gas from the manual valve can then pass through a particulate filter 204. The particulate filter 204 can prevent any impurities (which may be present in the gas) from reaching a pressure regulator 206. The filtered gas is then passed through a regulator solenoid valve 205. The regulator solenoid valve 205 can be a high pressure electro-mechanical valve. The regulator solenoid valve 205 does not permit the gas in the to flow to the pressure regulator 206, unless actuated by an external entity (such as the ECU (Engine Control Unit) of the vehicle, or any other equivalent means). In an embodiment herein, the regulator solenoid valve 205 can be a normally closed electrically driven gas valve. The regulator solenoid valve 205 can only remain open while the regulator solenoid valve 205 is provided with electrical power. If the power is cut to the regulator solenoid valve 205, the regulator solenoid valve 205 can automatically close and prevent further flow of gas.
[0029] The gas can then flow to the pressure regulator 206. The pressure regulator 206 can reduce the pressure of the gas to a gauge pressure pre-defined level using at least one of an electronic and/or mechanical means. The pre-defined level of pressure depends on the configuration of the injectors 208. In an example, the pre-defined pressure level can be suitable value between 2 bar to 10 bar. The gas is supplied to a gas rail 207. The gas rail 207 comprises of at least one one low pressure transducer 208. The low pressure transducer 209 can monitor the pressure in the gas rail 207 in order to ensure the operation of engine within a pre-defined injection pressure range. The gas rail further comprises of a plurality of injectors 208, which can inject the gas into the intake line after compressor out.
[0030] FIG. 3 depicts an internal valve. The internal valve 105 can comprise of a pressure relief device 301. The pressure relief device 301 will release the gas, in case of a potential issue, such as a buildup of excess pressure; temperature exceeding a design set temperature, and so on. The internal valve 105 can also comprise an inbuilt excess flow valve 302 in order to prevent rapid dispersion of gas in case of a puncture in the gas line between the cylinder 101 and the non-return valve 203.
[0031] FIG. 4 depicts a gas powered vehicle system. The engine 401 operates based on a principle such as spark ignition, dual fuel mode or stoichiometric mode of operation, and so on. The ECU 402 controls the engine 401. The ECU 402 can be connected to a plurality of sensors present in the vehicle, such as a sensors which provides the current speed/acceleration/deceleration of the vehicle, a cam sensor, a crank sensor, a throttle sensor, a MAP (Manifold Absolute Pressure) sensor, knock sensor and so on. The ECU 402 can also receive signals from a gravimetric position sensor, gyroscope, accelerometer, airbag sensors, impact sensors/switches (positioned on the sides, front and/or rear of the vehicle), and so on. The ECU 402 can also receive signals from at least one gas sensor located in the engine compartment of the vehicle, passenger compartment of the vehicle, the cylinder 101, and so on.
[0032] The cylinder can be connected to the vent line 201 through the non-return valve 202. The non-return valve can comprise of an odorant and/or colouring means (such as a breakable capsule, a burst disc, an aerosol spray, and so on). When the vent line 201 is venting gas from the cylinder, the odorant and/or the colouring means can serve to provide a warning and/or a visual indicator that the gas is being vented. The pressure/temperature or pressure & temperature release means present in the internal valve 105 can be connected to the vent line through the non-return valve 202.
[0033] Gas stored in the cylinder 101 can be passed on to the internal valve 105 through solenoid system integrated with pressure and temperature measurement. The gas released from the internal valve 105 is passed on to the high pressure line 403. The high pressure line 403 can be configured to hold up to 1000 bar burst pressure. The gas is passed on to the pressure regulator 206, through a non-return valve 203, which reduces the pressure of the gas to the pre-defined pressure level. The gas at the pre-defined pressure level is passed on to the injector 208 through a flexible or rigid low pressure line.
[0034] On detecting an adverse condition, the ECU 402 can instruct the regulator 206 and/or the internal valve 105 to cut off the supply of gas. Examples of the adverse situation can be the vehicle toppling (which can be detected using gravimetric position sensor/gyroscope/accelerometer and so on), a gas leakage (which can be detected using the gas sensors), an accident/impact (which can be detected using the inputs from the airbag sensors/impact switches/impact sensors) and so on.
[0035] FIG. 5 depicts an example scenario of a leakage in the high pressure line, according to embodiments as disclosed herein. The internal valve 105 can measure the pressure of the gas flowing to the high pressure line from the cylinder 101. The measured pressure can be communicated to the ECU 402. The non-return valve 203 or the regulator 206 can measure the pressure of the gas, after the high pressure line 403. In an embodiment herein, the pressure can be measured at any point after the high pressure line 403. The measured pressure can be communicated to the ECU 402. The ECU 402 can determine the drop in the pressure (if any). If the pressure drop is greater than a first pre-defined pressure limit, the ECU 402 can send an indication to the regulator 206 and the internal valve 105 to cut off the supply of the gas. The ECU 402 can also provide an indication to a user of the vehicle about the leakage using an interface present in the vehicle (such as the information cluster of the vehicle, the infotainment system of the vehicle, the visual panel of the vehicle, and so on), any external pre-configured device (such as a mobile phone, smart phone, tablet, and so on), and so on. If the pressure drop is between the first pre-defined pressure limit and a second pre-defined pressure limit, the ECU 402 can provide an indication to the user of the vehicle about the potential leakage using an interface present in the vehicle, any external pre-configured device, and so on. If the pressure drop is less than the second pre-defined pressure limit, the ECU 402 can take no action. In an embodiment herein, the user can view the pressure difference (if any) in real-time. The pre-defined pressure limit can depend on factors such as the vehicle, the weight of the vehicle, the category of the vehicle (passenger vehicle, utility vehicle, and so on).
[0036] In an example herein, if the pressure drop is greater than 15 bar/minute, the ECU 402 can send an indication to the regulator 206 and the internal valve 105 to cut off the supply of the gas. The ECU 402 can also provide an indication to a user of the vehicle about the leakage using an interface present in the vehicle, any external pre-configured device, and so on. If the pressure drop is between 15 bar/minute and 5 bar/minute, the ECU 402 can provide an indication to the user of the vehicle about the potential leakage using an interface present in the vehicle, any external pre-configured device, and so on. If the pressure drop is less 5 bar/minute, the ECU 402 can take no action.
[0037] FIG. 6 depicts an example scenario of a leakage in the low pressure line, according to embodiments as disclosed herein. If there is a leakage on a low pressure line or in the regulator 206 or regulator failure, then there is a change in the pressure at the output of the regulator 206. If there is a leakage on a low pressure line or in the regulator 206, the pressure at the output of the regulator 206 will be lower than expected. If there is a failure in the regulator 206, the pressure at the output of the regulator 206 will be higher than expected. A pressure sensor is present at the output of the regulator 206. The output pressure sensor senses the pressure at the output of the regulator 206 and provides the sensed pressure to the ECU 402. The ECU 402 checks if the outlet pressure is greater than a pre-defined pressure limit when the vehicle is in ON condition and/or a pressure drop greater than a pre-defined pressure threshold when the engine is in OFF condition, the ECU 402 can provide a signal to the internal valve 105 to cut off the supply of gas (when the vehicle is ON).
[0038] In an example, if the ECU 401 detects that the outlet pressure is greater than 10 bar or if there is a pressure drop greater than 0.1 bar /min in engine off condition, the ECU 402 can infer that there is potential leakage either in low pressure line or the injector.
[0039] FIG. 7 depicts an example scenario where the vehicle is in an accident. On detecting an impact or an accident (based on inputs from at least one of the airbag sensors, the impact sensors/switches, a means to determine the angle of the center of gravity of the vehicle (such as the gravimetric sensors, the gyroscopes, and so on) and so on), the ECU 402 can cut off the hydrogen supply to the cylinder 401 and the regulator 207.
[0040] In an embodiment herein, if the gravimetric sensor detects that the angle of the vehicle is greater than an angular limit, the ECU 402 cuts off the hydrogen supply to the cylinder 401 and the regulator 207.
[0041] FIG. 8 depicts an example scenario when a fire and/or an explosion occur in or in the vicinity of the vehicle. If the vehicle catches or a fire is in the vicinity of the vehicle or there is heat build-up in the cylinder 401, the pressure and temperature inside the cylinder 401 will increase. On detecting the increasing temperature and/or pressure inside the cylinder 401, the ECU 402 can open the vent lines. The gas is vented through the vent lines, along with the odorant and/or the colouring agent.
[0042] 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.

STATEMENT OF CLAIMS
We claim:
1. A fuel system in a gas powered vehicle, the system comprising
a means to cut off supply of gas to engine of the vehicle, on detecting a gas leakage in a high pressure line in the fuel system;
a means to cut of supply of gas to the engine of the vehicle, on detecting a gas leakage in at least one of a low pressure line or in a regulator in the fuel system;
a means to cut of supply of gas to the engine of the vehicle, on detecting that the vehicle is an accident;
at least one vent line to vent gas from a cylinder, on detecting a fire in the vehicle; and
at least one non-return valve to prevent backflow of the gas.
2. The method, as claimed in claim 1, wherein the system is configured to cut off supply of gas to the engine of the vehicle, if difference between a measured pressure of gas flowing to the high pressure line and a measured pressure of gas after the high pressure line is greater than a threshold.
3. The method, as claimed in claim 1, wherein the system is configured to cut of supply of gas to the engine of the vehicle, on detecting that difference between pressure measured on the regulator is greater than at least one of
a pre-defined pressure limit when the vehicle is in ON condition; and
a pre-defined pressure threshold when the vehicle is in OFF condition.
4. The method, as claimed in claim 1, wherein the system is configured to cut of supply of gas to the engine of the vehicle on detecting at least one of
an input from at least one of an airbag sensor; and at least one impact sensor; and
an input from a means to determine angle of center of gravity of the vehicle is greater than an angular limit.
5. The method, as claimed in claim 1, wherein the system is configured to vent gas from the cylinder using the at least one vent line on detecting that at least one temperature and pressure in the cylinder has increased beyond a threshold.
6. The method, as claimed in claim 5, wherein the at least one vent line comprises of a non-return valve.
7. The method, as claimed in claim 5, wherein the vent line comprises at least one of an odorant; and a colouring means.

Dated this 26th November 2015

Signatures:
Name of the Signatory: Dr. Kalyan Chakravarthy

ABSTRACT
Safety system for gas powered vehicles. The embodiments herein generally relate to safety systems in vehicles, and more particularly to a safety system and method for gas powered vehicles. Embodiments herein disclose a system for ensuring safety in gas powered vehicles, by preventing and minimizing line leakages, fires and/or explosions in cases of accidents, prevention of backfire and so on.

FIG. 4
,CLAIMS:STATEMENT OF CLAIMS
We claim:
1. A fuel system in a gas powered vehicle, the system comprising
a means to cut off supply of gas to engine of the vehicle, on detecting a gas leakage in a high pressure line in the fuel system;
a means to cut of supply of gas to the engine of the vehicle, on detecting a gas leakage in at least one of a low pressure line or in a regulator in the fuel system;
a means to cut of supply of gas to the engine of the vehicle, on detecting that the vehicle is an accident;
at least one vent line to vent gas from a cylinder, on detecting a fire in the vehicle; and
at least one non-return valve to prevent backflow of the gas.
2. The method, as claimed in claim 1, wherein the system is configured to cut off supply of gas to the engine of the vehicle, if difference between a measured pressure of gas flowing to the high pressure line and a measured pressure of gas after the high pressure line is greater than a threshold.
3. The method, as claimed in claim 1, wherein the system is configured to cut of supply of gas to the engine of the vehicle, on detecting that difference between pressure measured on the regulator is greater than at least one of
a pre-defined pressure limit when the vehicle is in ON condition; and
a pre-defined pressure threshold when the vehicle is in OFF condition.
4. The method, as claimed in claim 1, wherein the system is configured to cut of supply of gas to the engine of the vehicle on detecting at least one of
an input from at least one of an airbag sensor; and at least one impact sensor; and
an input from a means to determine angle of center of gravity of the vehicle is greater than an angular limit.
5. The method, as claimed in claim 1, wherein the system is configured to vent gas from the cylinder using the at least one vent line on detecting that at least one temperature and pressure in the cylinder has increased beyond a threshold.
6. The method, as claimed in claim 5, wherein the at least one vent line comprises of a non-return valve.
7. The method, as claimed in claim 5, wherein the vent line comprises at least one of an odorant; and a colouring means.