TECHNICAL FIELD

The present disclosure, in general, relates to a gaseous fuel leakage
detection for bi-fuel vehicle, and, more particularly, to system and method for
detecting gaseous fuel leakage and inhibiting gaseous fuel supply upon detection
of gaseous fuel leakage.

BACKGROUND

Background description includes information that may be useful in
understanding the present disclosure. It is not an admission that any of the
information provided herein is prior art or relevant to the presently claimed
subject matter, or that any publication specifically or implicitly referenced is prior
art.
[0003] As is well known to those skilled in the art, a bi-fuel vehicle is used for
fuel efficiency, economical efficiency of fuel, exhaust gas, and so on. For
example, the bi-fuel vehicle may use both gaseous fuel such as Compressed
Natural Gas (CNG), Liquefied Petroleum Gas (LPG), Liquefied Natural Gas
(LNG), etc., and liquid fuel such as Petrol, Diesel, Gasoline etc.
[0004] The bi-fuel vehicle may drive on either liquid fuel or gaseous fuel
according to a driver's selection. When the bi-fuel vehicle drives on liquid fuel, it
is referred to as a liquid mode, while when the bi-fuel vehicle drives on gaseous
fuel, it is referred to as a gaseous mode.
[0005] In the bi-fuel vehicle, electronic control unit (ECU) is used to switch
between liquid mode and gaseous mode. In some cases, switching is automatic
based on a controlled programme and in some cases it is manual. Further, some
vehicle may have two ECUs where one ECU is an engine control module (ECM)
which acts as a master ECU for performing engine management system (EMS)
3
related functions. Second ECU is a bi-fuel ECU which acts as a slave ECU for
performing EMS related functions including actuation of injectors of both fuel
sources and converting vehicle from liquid mode to gaseous mode or vice-versa.
[0006] In another embodiment, the ECU may perform EMS related functions
including actuation of injectors of both fuel sources and converting vehicle from
liquid mode to gaseous mode or vice-versa.
[0007] In the CNG fuel or LNG fuel that are odourless gases, therefore,
detection of leakage of the same is difficult. For safety of Bi-fuel vehicles, it is
necessary to detect the leakage of gas before cranking the engine to avoid any
accident.
[0008] To detect the leakage of gaseous fuel in vehicle, plurality of existing
technologies provide solutions based on pressure and temperature values in fuel
tank. However, each existing technology has its disadvantage.
[0009] None of the existing technology is accurate to measure fuel leakage
and inhibit gaseous fuel supply at high pressure side only.
[0010] In some existing detection systems, fuel leakage is detected using
pressure estimation based on temperature measurement at different time periods.
Such systems fail to provide accurate leakage detection as they depend on
estimation algorithms and are more prone to false positive or false negative
leakage indications. Also, in some other existing detection systems, two separate
sets of pressure and temperature sensors are used in high and low pressure sides of
gaseous fuel supply system. This translates to higher cost and lower robustness.
Therefore, there is need in the art to detect gaseous fuel leakage at high pressure
side with more accuracy and low cost, and also inhibiting the fuel supply based on
detection of gaseous fuel leakage.
OBJECTS OF THE DISCLOSURE
[0011] Some of the objects of the present disclosure, which at least one
embodiment herein satisfy, are listed hereinbelow.
4
[0012] It is a general object of the present disclosure to provide system and
method for detecting gaseous fuel leakage at high pressure side in a bi-fuel
vehicle.
[0013] It is another object of the present disclosure to provide system and
method for inhibiting supply of gaseous fuel upon detection of fuel leakage at the
high pressure side in the bi-fuel vehicle.
[0014] It is another object of the present disclosure to provide indication of
fuel leakage at high pressure side in the bi-fuel vehicle.
[0015] It is another object of the present disclosure to avoid further leakage of
fuel in fuel hose by shutting tank shut-off valve.
[0016] It is another object of the present disclosure to detect gaseous fuel
leakage at key-accessory event before engine is ignited.
[0017] It is another object of the present disclosure to prevent draining of
battery power by measuring pressure and temperature during key-accessory event,
and not at the key-off event.
[0018] It is another object of the present disclosure to provide a simple and
cost effective, and accurate solution with single pressure and temperature sensor
to detect fuel leakage at key-accessory event.
[0019] These and other objects and advantages of the present invention will
be apparent to those skilled in the art after a consideration of the following
detailed description taken in conjunction with the accompanying drawings in
which a preferred form of the present invention is illustrated.
SUMMARY
[0020] This summary is provided to introduce concepts related to system and
method for detecting gaseous fuel leakage at high pressure side in a bi-fuel
vehicle. The concepts are further described below in the detailed description. This
summary is not intended to identify key features or essential features of the
5
claimed subject matter, nor is it intended to be used to limit the scope of the
claimed subject matter.
[0021] The present disclosure relates to an Electronic Control Unit (ECU) to
detect gaseous fuel leakage at high pressure side in Bi-fuel vehicle. The Electronic
Control Unit (ECU) includes a leakage detection system having a fuel leakage
detection module coupled to the processor to receive and store temperature and
pressure values from temperature sensor and pressure sensor during last key-off
event when the engine stops in gaseous mode and during last gaseous fuel to
liquid fuel switchover event. The system further receives, from memory,
temperature and pressure values of the last key-off event when the engine stops in
gaseous mode and of last gaseous fuel to liquid fuel switchover event when the
engine stops in liquid mode. The system calculates first number of moles (n1)
based on the received temperature (T1) and pressure (P1), and storing the same in
the memory. Further, the system receives temperature (T2) and pressure (P2) at
the high pressure side from the temperature sensor and the pressure sensor during
next key-accessory event, and calculates second number of moles (n2) based on
the received temperature (T2) and pressure (P2). The system compares calculated
first number of moles (n1) with the calculated second number of moles (n2) and
detects gaseous fuel leakage in the high pressure side when the calculated first
number of moles (n1) is more than the calculated second number of moles (n2).
[0022] In an aspect, the leakage detection system having a fuel supply module
coupled to the processor to close tank shut-off valve and regulator shut-off valve
when the calculated first number of moles (n1) is more than the calculated second
number of moles (n2).
[0023] In an aspect, the leakage detection system having a leakage indication
module coupled to the processor to transmit gaseous fuel leakage indication signal
to a display device when the calculated first number of moles (n1) is more than
the calculated second number of moles (n2).
[0024] In an aspect, the high pressure side includes gas tank and fuel hose up
to regulator.
6
[0025] In an aspect, the leakage detection system allows opening and closing
of tank shut-off valve during the next key-accessory event to measure the
temperature (T2) and the pressure (P2) at the high pressure side using the
temperature sensor and the pressure sensor, while regulator shut-off valve remains
closed.
[0026] The present disclosure further relates to a method for detecting gaseous
fuel leakage in high pressure side in vehicle. The method includes steps of
receiving and storing, in memory, pressure and temperature values from pressure
sensor and temperature sensor during last key-off event when the engine stops in
gaseous mode and during last gaseous fuel to liquid fuel switchover event. The
system includes steps of receiving, from memory, temperature and pressure values
of the key-off event when the engine stops in gaseous mode and of the last
gaseous fuel to liquid fuel switchover event when the engine stops in liquid mode.
The method also includes steps of calculating first number of moles (n1) based on
the received temperature (T1) and pressure (P1) and storing the same in the
memory. In further steps, receiving temperature (T2) and pressure (P2) at the high
pressure side from the temperature sensor and the pressure sensor during next
key-accessory event, and calculating second number of moles (n2) based on the
received temperature (T2) and pressure (P2); and storing the same in the memory.
In next step, comparing the calculated first number of moles (n1) with the
calculated second number of moles (n2) and detecting gaseous fuel leakage in the
high pressure side when the calculated first number of moles (n1) is more than the
calculated second number of moles (n2).
[0027] In an aspect, tank shut-off valve and regulator shut-off valve close
when the calculated first number of moles (n1) is more than the calculated second
number of moles (n2).
[0028] In an aspect, a gaseous fuel leakage indication signal is transmitted to a
display device when the calculated first number of moles (n1) is more than the
calculated second number of moles (n2).
7
[0029] Various objects, features, aspects, and advantages of the inventive
subject matter will become more apparent from the following detailed description
of preferred embodiments, along with the accompanying drawing figures in which
like numerals represent like components.
[0030] It is to be understood that the aspects and embodiments of the
disclosure described above may be used in any combination with each other.
Several of the aspects and embodiments may be combined to form a further
embodiment of the disclosure.
[0031] 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 DRAWINGS
[0032] The illustrated embodiments of the subject matter will be best
understood by reference to the drawings, wherein like parts are designated by like
numerals throughout. The following description is intended only by way of
example, and simply illustrates certain selected embodiments of devices, systems,
and methods that are consistent with the subject matter as claimed herein,
wherein:
[0033] Fig. 1 illustrates gaseous fuel supply layout with high pressure side and
low pressure side, in accordance with an exemplary embodiment of the present
disclosure;
[0034] Fig. 2 illustrates an architecture of a fuel supply control system with
electronic control unit for detecting gaseous fuel leakage, in accordance with an
exemplary embodiment of the present disclosure; and
[0035] Fig. 3 illustrates a method for ECU to detect gaseous fuel leakage in
the bi-fuel vehicle, in accordance with an exemplary embodiment of the present
disclosure.
8
[0036] 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 structures and methods illustrated
herein may be employed without departing from the principles of the disclosure
described herein.
DETAILED DESCRIPTION
[0037] The detailed description of various exemplary embodiments of the
disclosure is described herein with reference to the accompanying drawings. It
should be noted that the embodiments are described herein in such details as to
clearly communicate the disclosure. However, the amount of details provided
herein is not intended to limit the anticipated variations of embodiments; on the
contrary, the intention is to cover all modifications, equivalents, and alternatives
falling within the spirit and scope of the present disclosure as defined by the
appended claims.
[0038] It is also to be understood that various arrangements may be devised
that, although not explicitly described or shown herein, embody the principles of
the present disclosure. Moreover, all statements herein reciting principles, aspects,
and embodiments of the present disclosure, as well as specific examples, are
intended to encompass equivalents thereof.
[0039] The terminology used herein is for the purpose of describing particular
embodiments only and is not intended to be limiting of example embodiments. As
used herein, the singular forms “a”, “an” and “the” are intended to include the
plural forms as well, unless the context clearly indicates otherwise. It will be
further understood that the terms “comprises”, “comprising”, “includes” and/or
“including,” when used herein, specify the presence of stated features, integers,
steps, operations, elements and/or components, but do not preclude the presence
or addition of one or more other features, integers, steps, operations, elements,
components and/or groups thereof.
9
[0040] It should also be noted that in some alternative implementations, the
functions/acts noted may occur out of the order noted in the figures. For example,
two figures shown in succession may, in fact, be executed concurrently or may
sometimes be executed in the reverse order, depending upon the functionality/acts
involved.
[0041] Unless otherwise defined, all terms (including technical and scientific
terms) used herein have the same meaning as commonly understood by one of
ordinary skill in the art to which example embodiments belong. It will be further
understood that terms, e.g., those defined in commonly used dictionaries, should
be interpreted as having a meaning that is consistent with their meaning in the
context of the relevant art and will not be interpreted in an idealized or overly
formal sense unless expressly so defined herein.
[0042] Fig. 1 illustrates gaseous fuel supply layout. The gaseous fuel supply
layout includes high pressure side 1 and low pressure side 2. The high pressure
side 1 comprises gas tank 3, tank shut-off valve 6, fuel hose 5, pressure sensor 10,
temperature sensor 9 and regulator shut-off valve 7. The high pressure side 1
extends up to regulator 8 that regulates the gaseous fuel into low pressure for
supply in internal combustion engine through gas fuel injectors 4 via fuel rail 11.
The low pressure side 2 is generally at engine side. The regulator 8 controls the
pressure of the gaseous fuel and converts it from high to low pressure. In the high
pressure side 1, the pressure sensor 10 and the temperature sensor 9 can be
positioned either along fuel hose 5 or can be positioned in the gas tank 3. When
the tank shut-off valve 6 is open and the regulator shut-off valve 7 is closed, the
high pressure side 1 has gaseous fuel from gas tank 3 till regulator shut-off valve
7. Generally, the fuel tank 3 is positioned at rear end of the vehicle and the fuel
hose 5 transfers the gaseous fuel from the fuel tank 3 to the fuel rail 11 that is
positioned at front end or engine cabin of the vehicle.
[0043] Because of the presence of gaseous fuel at high pressure in high
pressure side, it is required to detect fuel leakage at high pressure side 1 along the
fuel hose 5 and the gas tank 3. To detect, gas fuel leakage at high pressure side 1,
10
the pressure sensor 10 and the temperature sensor 9 is positioned at the high
pressure side 1 to measure pressure and temperature of gas and send the measured
values for further calculations.
[0044] The present disclosure uses the Ideal Gas Equation 1 to calculate
number of moles of gas at high pressure side 1 at two events to detect fuel
leakage.
[0045] 𝑃𝑉􀵌𝑛𝑅𝑇…………………………………..equation 1
[0046] Where P is pressure in high pressure side, V is volume of gaseous fuel
in high pressure side, n is number of moles of gas in high pressure side, R is gas
constant and T is temperature of gas in high pressure side. In the present
disclosure, volume V and R remains constant. Therefore, temperature and
pressure are used to calculate number of moles of gaseous fuel in the high
pressure side.
[0047] Referring to fig. 2 illustrating an architecture of a fuel supply control
system. In FIG. 2, the fuel supply control system includes an Engine Control Unit
(ECU) 200 that controls fuel supply in the vehicle along with other functions. The
ECU 200 switches the vehicle in liquid mode and gaseous mode manually or by
controlled program.
[0048] As shown in the fig. 2, the ECU 200 controls both the gaseous fuel
injection and liquid fuel Injection. The ECU 200 controls the opening and closing
of tank shut-off valve 6, regulator shut-off valve 7, and gas injectors 4. For supply
of gaseous fuel to the engine, both the tank shut-off valve 6 and the regulator shutoff
valve 7 should be in open condition.
[0049] Fig. 2 also illustrates functional components of the ECU 200 proposed
herein. Further, the present ECU 200 can be a bi-fuel ECU. The ECU 200
includes a processor(s) 201, an interface(s) 202, and a memory 203. The
processor(s) 201 may be implemented as one or more microprocessors,
microcomputers, microcontrollers, digital signal processors, central processing
units, logic circuitries, and/or any devices that manipulate data based on
11
operational instructions. Among other capabilities, the one or more processor(s)
201 are configured to fetch and execute computer-readable instructions and one or
more routines stored in the memory 203. The memory 203 may store one or more
computer-readable instructions or routines, which may be fetched and executed to
manage warehouse over a network service. The memory 203 may include any
non-transitory storage device including, for example, volatile memory such as
RAM, or non-volatile memory such as EPROM, flash memory, and the like.
[0050] The interface(s) 202 may include a variety of interfaces, for example,
interfaces for data input and output devices referred to as I/O devices, storage
devices, and the like. The interface(s) 202 may facilitate communication of the
ECU 200 with various devices coupled to the ECU 200. The interface(s) 202 may
also provide a communication pathway for one or more components of the ECU
200. Examples of such components include, but are not limited to, leakage
detection system 300 having a fuel leakage detection module 301, fuel supply
module 302, and leakage indication module 303. Further, interface 202 provide
communication pathway between the temperature sensor 9, the pressure sensor 10
with the leakage detection system 300 (as shown in fig. 2).
[0051] The fuel leakage detection module 301, the fuel supply module 302,
and the leakage indication module 303 may be implemented as a combination of
hardware and programming (for example, programmable instructions) to
implement one or more functionalities to detect leakage of gaseous fuel. In
examples described herein, such combinations of hardware and programming may
be implemented in several different ways. For example, the programming for the
fuel leakage detection module 301, the fuel supply module 302, and the leakage
indication module 303 may be processor executable instructions stored on a nontransitory
machine-readable storage medium and the hardware for the fuel leakage
detection module 301, the fuel supply module 302, and the leakage indication
module 303 may include a processing resource (for example, one or more
processors), to execute such instructions. In the present examples, the machinereadable
storage medium may store instructions that, when executed by the
12
processing resource, implement the fuel leakage detection module 301, the fuel
supply module 302, and the leakage indication module 303. In such examples, the
ECU 200 may include the machine-readable storage medium storing the
instructions and the processing resource to execute the instructions or the
machine-readable storage medium may be separate but accessible to the ECU 200
and the processing resource. In other examples, the leakage detection system 300
may be implemented by electronic circuitry.
[0052] The fuel leakage detection module 301 coupled to the processor 201
and coupled to the temperature sensor 9 and the pressure sensor 10 via the
interface 202. The temperature sensor 9 and the pressure sensor 10 measure
temperature and pressure values at the high pressure side 1 and send the measured
values to the fuel leakage detection module 301, via memory 203. The fuel
leakage detection module 301 stores, in the memory 203, the pressure and
temperature values during last key-off event when the engine stops in gaseous
mode and during last gaseous fuel to liquid fuel switchover event. The system
receives, from the memory, temperature and pressure values of the key-off event
when the engine stops in gaseous mode and of the last gaseous fuel to liquid fuel
switchover event when the engine stops in liquid mode. The fuel leakage
detection module 301 calculates first number of moles (n1) based on the received
temperature T1 and the pressure P1 from the high pressure side 1.
[0053] Accordingly, the fuel leakage detection module 301 calculates:
[0054] 𝑛1􀵌􀯉􀯍􀬵􀬵􀯋􀯏 ………………………………….equation 2
[0055] During the next key-accessory event, the fuel leakage detection
module 301 again records the temperature T2 and the pressure P2 values and
calculates the remaining second number of moles (n2) in the high pressure side 1.
[0056] 𝑛2􀵌􀯉􀯍􀬶􀬶􀯋􀯏 ………………………………equation 3
[0057] To calculate the pressure P2 in high pressure side 1 including gaseous
fuel tank and high pressure side pipes or fuel hose, the fuel detection module 301
allows quick opening and closing of the tank shut-off valve 6 at the key-accessory
13
event, while keeping regulator shut-off valve 7 closed. The pressure P2 values are
taken when the tank shut-off valve 6 is in open position and regulator shut-off
valve 7 is in closed position. This ensures that the pressure P2 is calculated for the
entire high pressure side. Further, it also helps in detecting leakage in the entire
high pressure side and not just in the gas tank 3.
[0058] The fuel leakage detection module 301 compares the calculated first
number of moles n1 and calculated second number of moles n2.
[0059] n1>n2………………………………….equation 4
[0060] The fuel leakage detection module 301 detects gaseous fuel leakage in
the high pressure side 1 when the calculated first number of moles n1 is more than
the calculated second number of moles n2. For no leakage of gaseous fuel, first
number of moles n1 must be equal to second number of moles n2.
[0061] Based on the detected leakage of gaseous fuel by the fuel leakage
detection module 301, the fuel supply module 302 coupled to the processor 201
and the fuel leakage detection module 301 closes the tank shut-off valve 6 and
regulator shut-off valve 7 to inhibit supply of gaseous fuel to the engine to avoid
any accident when the calculated first number of moles n1 is more than the
calculated second number of moles n2. The fuel leakage detection module 301
may further prohibit switchover from liquid mode to gaseous mode till the leakage
is rectified.
[0062] In another aspect of the present subject matter, based on the detected
leakage of gaseous fuel by the fuel leakage detection module 301, the leakage
indication module 303 coupled to the processor 201 and the fuel leakage detection
module 301 transmits gaseous fuel leakage indication signal to a display device
when the calculated first number of moles n1 is more than the calculated second
number of moles n2. Further, the display device can be an instrument panel
cluster (IPC) of the vehicle.
[0063] With the indication of gaseous fuel leakage and inhibition of gaseous
fuel supply, the leakage place can be identified and rectified. Till the rectification,
14
the ECU 200 does not allow vehicle to be used in gaseous mode by prohibiting
switchover from liquid mode to gaseous mode. With the present system 300, the
gaseous fuel leakage is detected in the entire high pressure side including fuel
tank and fuel hose up to regulator 8. Upon detection, the leakage detection system
300 inhibits supply of gaseous fuel to the vehicle engine and indicates the fuel
leakage error in the display device.
[0064] FIG. 3 illustrates a method 400 for detecting gaseous fuel leakage in
bi-fuel vehicle, according to an implementation of the present disclosure. The
order in which the method 400 is described is not intended to be construed as a
limitation, and any number of the described method blocks can be combined in
any appropriate order to carry out the method 400 or an alternative method.
Additionally, individual blocks may be deleted from the method 400 without
departing from the scope of the subject matter described herein.
[0065] At block 402, the method 400 includes receiving and storing in
memory, by leakage detection system 300, temperature and pressure values from
temperature sensor 9 and pressure sensor 10 during last key-off event when the
engine stops in gaseous mode and during last gaseous fuel to liquid fuel
switchover event.
[0066] At block 404, the method 400 includes receiving, from memory,
temperature and pressure values of key-off event when the engine stops in
gaseous mode and of last gaseous fuel to liquid fuel switchover event when the
engine stops in liquid mode.
[0067] At block 406, the method 400 includes calculating, by the leakage
detection system 300, first number of moles (n1) based on the received
temperature (T1) and pressure (P1).
[0068] At block 408, the method 400 includes receiving, by the leakage
detection system 300, temperature (T2) and pressure (P2) at the high pressure side
1 from the temperature sensor 9 and the pressure sensor 10 during next keyaccessory
event. The method further comprises opening and closing tank shut-off
15
valve 6 during the key-accessory event to allow measurement of the temperature
(T2) and the pressure (P2) at the high pressure side 1 using the temperature sensor
9 and the pressure sensor 10, while keeping regulator shut-off valve 7 in closed
position.
[0069] At block 410, the method 400 includes calculating, by the leakage
detection system 300, second number of moles (n2) based on the received
temperature (T2) and pressure (P2).
[0070] At block 412, the method includes comparing, by the leakage detection
system 300, the calculated first number of moles (n1) with the calculated second
number of moles (n2).
[0071] At block 414, the method includes indicating in the display device, by
the leakage detection system 300, gaseous fuel leakage in the high pressure side 1
when the calculated first number of moles (n1) is more than the calculated second
number of moles (n2). In another aspect, the method includes closing tank shutoff
valve 6 and regulator shut-off valve 7 when the calculated first number of
moles (n1) is more than the calculated second number of moles (n2) to inhibit
supply of gaseous fuel to the vehicle engine.
[0072] In yet another embodiment, the method includes transmitting gaseous
fuel leakage indication signal to a display device when the calculated first number
of moles (n1) is more than the calculated second number of moles (n2).
[0073] Technical advantages:
[0074] (1) The leakage detection system detects gaseous fuel leakage when
the vehicle is parked or in key-off condition.
[0075] (2) The leakage detection system performs the calculation using single
set of pressure sensor and temperature sensor, which translates to low cost and
high robustness.
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[0076] (3) The present system does calculation using number of moles, which
is one of the most accurate way of detecting gaseous fuel leakage. Unlike other
systems which depends upon pressure or temperature change estimation.
[0077] (4) The present system compares the number of moles on keyaccessory
event, before the engine is cranked, or key-on event. This helps in
detecting leakage before the engine is ignited.
[0078] (5) The present system keeps the valves and the regulators in shut-off
condition when leakage is detected, thereby minimizing any chances of mishaps.
[0079] (6) The present system calculates pressure and temperature in keyaccessory
event; and not in key-off event, thereby protecting from undesired
power drain when car is parked for longer periods.
[0080] The above description does not provide specific details of the
manufacture or design of the various components. Those of skill in the art are
familiar with such details, and unless departures from those techniques are set out,
techniques, known, related art or later developed designs and materials should be
employed. Those in the art can choose suitable manufacturing and design details.
[0081] It should be understood, however, that all of these and similar terms
are to be associated with the appropriate physical quantities and are merely
convenient labels applied to these quantities. Unless specifically stated otherwise,
as apparent from the discussion herein, it is appreciated that throughout the
description, discussions utilizing terms such as “receiving,” or “transmitting,” or
the like, refer to the action and processes of an electronic control unit, or similar
electronic computing device, that manipulates and transforms data represented as
physical (electronic) quantities within the control unit’s registers and memories
into other data similarly represented as physical quantities within the control unit
memories or registers or other such information storage, transmission or display
devices.
17
[0082] Further, the terminology used herein is for the purpose of describing
particular embodiments only and is not intended to be limiting of the disclosure. It
will be appreciated that several of the above-disclosed and other features and
functions, or alternatives thereof, may be combined into other systems or
applications. Various presently unforeseen or unanticipated alternatives,
modifications, variations, or improvements therein may subsequently be made by
those skilled in the art without departing from the scope of the present disclosure
as encompassed by the following claims.
[0083] The claims, as originally presented and as they may be amended,
encompass variations, alternatives, modifications, improvements, equivalents, and
substantial equivalents of the embodiments and teachings disclosed herein,
including those that are presently unforeseen or unappreciated, and that, for
example, may arise from applicants/patentees and others.
[0084] It will be appreciated that variants of the above-disclosed and other
features and functions, or alternatives thereof, may be combined into many other
different systems or applications. Various presently unforeseen or unanticipated
alternatives, modifications, variations, or improvements therein may be
subsequently made by those skilled in the art which are also intended to be
encompassed by the following claims.

We claim:

1. An Electronic Control Unit (ECU) (200) having a processor (201) and
memory (203) to detect gaseous fuel leakage in high pressure side (1) of
vehicle, the Electronic Control Unit (ECU) (200) comprising:
a memory (203);
a leakage detection system (300) having a fuel leakage detection
module (301) coupled to the processor (201) to:
store, in the memory (203), temperature and pressure values
from temperature sensor (9) and pressure sensor (10) during last keyoff
event when the engine stops in gaseous mode and during last
gaseous fuel to liquid fuel switchover event;
receive, from the memory (203), temperature (T1) and pressure
(P1) values of last key-off event when the engine stops in gaseous
mode and of last gaseous fuel to liquid fuel switchover event when
the engine stops in liquid mode;
calculate first number of moles (n1) based on the received
temperature (T1) and pressure (P1);
receive temperature (T2) and pressure (P2) of the high pressure
side (1) from the temperature sensor (9) and the pressure sensor (10)
during next key-accessory event;
calculate second number of moles (n2) based on the received
temperature (T2) and pressure (P2);
compare calculated first number of moles (n1) with the
calculated second number of moles (n2); and
detect gaseous fuel leakage in the high pressure side (1) when
the calculated first number of moles (n1) is more than the calculated
second number of moles (n2).
19
2. The Electronic Control Unit (ECU) (200) as claimed in claim 1, wherein
the leakage detection system (300) having a fuel supply module (302)
coupled to the processor (201) to close tank shut-off valve (6) and
regulator shut-off valve (7) when the calculated first number of moles (n1)
is more than the calculated second number of moles (n2).
3. The Electronic Control Unit (ECU) (200) as claimed in claim 1, wherein
the leakage detection system (300) having a leakage indication module
(303) coupled to the processor (201) to transmit gaseous fuel leakage
indication signal to a display device when the calculated first number of
moles (n1) is more than the calculated second number of moles (n2).
4. The Electronic Control Unit (ECU) (200) as claimed in claim 1, wherein
the high pressure side (1) includes gas tank (3) and fuel hose (5) up to
regulator (8).
5. The Electronic Control Unit (ECU) (200) as claimed in claim 1, wherein
the leakage detection system (300) allows quickly opening and closing of
tank shut-off valve (6) during the next key-accessory event to measure the
temperature (T2) and the pressure (P2) at the high pressure side (1) using
the temperature sensor (9) and the pressure sensor (10), while keeping
regulator shut-off valve 7 in closed position.
6. The Electronic Control Unit (ECU) (200) as claimed in claim 1, wherein
the vehicle is Bi-fuel vehicle.
7. A method (400) for detecting gaseous fuel leakage in high pressure side
(1) in vehicle, the method comprising:
storing (402) in memory (203), by leakage detection system
(300), temperature and pressure values from temperature sensor (9)
and pressure sensor (10) during last key-off event when the engine
stops in gaseous mode and during last gaseous fuel to liquid fuel
switchover event;
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receiving (404), by leakage detection system (300),
temperature (T1) and pressure (P1) values from the memory of last
key-off event when the engine stops in gaseous mode and of last
gaseous fuel to liquid fuel switchover event when the engine stops in
liquid mode;
calculating (406), by the leakage detection system (300), first
number of moles (n1) based on the received temperature (T1) and
pressure (P1);
receiving (408), by the leakage detection system (300),
temperature (T2) and pressure (P2) at the high pressure side (1) from
the temperature sensor (9) and the pressure sensor (10) during next
key-accessory event;
calculating (410), by the leakage detection system (300),
second number of moles (n2) based on the received temperature (T2)
and pressure (P2);
comparing (412), by the leakage detection system (300), the
calculated first number of moles (n1) with the calculated second
number of moles (n2); and
indicating (414) in the display device, by the leakage detection
system (300), gaseous fuel leakage in the high pressure side (1)
when the calculated first number of moles (n1) is more than the
calculated second number of moles (n2).
8. The method (400) as claimed in claim 7, wherein the method (400) further
comprising:
closing tank shut-off valve (6) and regulator shut-off valve
(7) when the calculated first number of moles (n1) is more than the
calculated second number of moles (n2).
9. The method (400) as claimed in claim 7, wherein the method (400) further
comprising:
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transmitting gaseous fuel leakage indication signal to a
display device when the calculated first number of moles (n1) is
more than the calculated second number of moles (n2).
10. The method (400) as claimed in claim 7, wherein the high pressure side (1)
includes gas tank (3) and fuel hose (5) up to regulator (8).
11. The method (400) as claimed in claim 7, wherein the tank shut-off valve
(6) quickly opens and closes during the next key-accessory event to allow
measurement of the temperature (T2) and the pressure (P2) at the high
pressure side (1) using the temperature sensor (9) and the pressure sensor
(10), while keeping regulator shut-off valve 7 in closed position.