TECHNICAL FIELD
[001] The embodiments herein relate to a system and a method for regulating primary fuel flow to a dual fuel engine for better substitution of at least a portion of primary fuel with corresponding amount of a secondary fuel to the dual fuel engine during at least one of a part throttle operation and a full throttle operation in a vehicle. Further, embodiments herein relate to a system and a method for restricting primary fuel flow to a dual fuel engine during refilling of fuel (primary fuel and/or secondary fuel) to at least one fuel storage tank of a vehicle.
BACKGROUND
[002] Duel fuel engine is a type of engine which combusts two different types of fuels to reduce emissions and improve operating economy. Usually, the duel fuel engine is a compression-ignited (CI) engine which operates on a primary fuel and a secondary fuel. The primary fuel includes any of diesel, petro-diesel, bio-diesel and so on. The secondary fuel includes any of compressed natural gas (CNG), liquefied petroleum Gas (LPG) and so on. In the duel fuel engine (hereinafter engine), the diesel is injected directly into a combustion chamber and the CNG is inducted into the engine intake manifold with air or directly into engine cylinder. The inducted CNG results in reduction in the flow of diesel depending on the operating zone of the engine.
[003] The dual fuel engine is associated with a mechanical fuel injection pump which is used to control the primary fuel flow to the engine. The position of the fuel injection pump lever is almost around same operating angle for different engine speed and engine load which in turn limits the flexibility in controlling diesel flow at different operating zones. Therefore, controlling the diesel flow from the fuel injection pump to the

duel fuel engine is difficult and is one of the challenges posed to the original equipment manufacturers (OEM’S).
[004] Generally, fuel substitution rate is most important in dual fuel operation as this determines the operating economy which benefits the user gains when the engine is running on dual fuel mode. It is difficult to interpret the CNG flow to the engine based on the position of the fuel injection pump lever and engine speed. During full throttle operation and part throttle operation, diesel is provided to the engine resulting in limited or zero CNG flow to the engine which in turn creates a negative impact on total fuel consumption and emissions. For example, the diesel flow to the engine remains same when the fuel injection pump lever is in full lock position (100% throttle) and substitution of diesel by CNG to the engine is not possible in this operating zone which in turn reduces the overall fuel efficiency and increases emissions.
[005] Usually, the primary fuel flows to the duel fuel engine during refilling of secondary fuel in a secondary fuel storage tank of the vehicle. Therefore, controlling or restricting the primary fuel flow to the dual fuel engine during refilling of secondary fuel in the secondary fuel storage tank is difficult and is one of the challenges posed to the original equipment manufacturers (OEM).
[006] Therefore, there exists a need for a system (fuel control system) and a method for regulating primary fuel flow to a dual fuel engine for better substitution of at least a portion of primary fuel with corresponding amount of a secondary fuel to the dual fuel engine during at least one of a part throttle operation and a full throttle operation in a vehicle, and also based on operating load of the duel fuel engine, which obviates the aforementioned drawbacks. Further, there exists a need for a system and a method for restricting primary fuel flow to a dual fuel engine

during refilling of fuel (primary fuel and/or secondary fuel) to at least one fuel storage tank of a vehicle.
OBJECTS
[007] The principal object of an embodiment of this invention is to provide a system (fuel control system) for regulating primary fuel flow to an all speed governed dual fuel engine, which facilitates better substitution of at least a portion of primary fuel with corresponding amount of a secondary fuel to the dual fuel engine during at least one of a part throttle operation and a full throttle operation in a vehicle and also based on operating load of the dual fuel engine.
[008] Another object of an embodiment of this invention is to provide a method for regulating primary fuel flow to an all speed governed dual fuel engine, which facilitates better substitution of at least a portion of primary fuel with corresponding amount of a secondary fuel to the dual-fuel engine during at least one of a part throttle operation and a full throttle operation in a vehicle and also based on operating load of the dual-fuel engine.
[009] Another object of an embodiment of this invention is to provide a system (fuel control system) for regulating primary fuel flow to an all speed governed dual fuel engine during a full throttle operation in a vehicle, which reduces emission, improves substitution of primary fuel, improves overall fuel economy and improves operating economy.
[0010] Another object of an embodiment of this invention is to provide a fuel control system in a vehicle, which achieves maximum primary fuel substitution by reducing the excess primary fuel flow to an all speed governed dual-fuel engine and increasing secondary fuel flow to the dual-fuel engine thereby reduces emissions during at least one of a part

throttle operation and a full throttle operation in a vehicle and also based on operating load of the dual-fuel engine.
[0011] Another object of an embodiment of this invention is to provide a system (fuel control system) for restricting primary fuel flow to a dual-fuel engine during refilling of a fuel (primary fuel and/or secondary fuel) in at least one fuel storage tank of a vehicle.
[0012] Yet, another object of an embodiment of this invention is to provide a method for restricting primary fuel flow to a dual-fuel engine during refilling of a fuel (primary fuel and/or secondary fuel) in at least one fuel storage tank of a vehicle.
[0013] A further object of an embodiment of this invention is to provide a system for regulating primary fuel flow to a dual-fuel engine for better substitution of at least a portion of primary fuel with corresponding amount of a secondary fuel to the dual-fuel engine during at least a part throttle operation in a vehicle and when the dual-fuel engine is at a full load condition.
[0014] These and other 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
[0015] The embodiments of the invention are 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:
[0016] Fig. 1 depicts a schematic view of a system for regulating primary fuel flow to an all speed governed dual-fuel engine in at least one of a part throttle operation and a full throttle operation in a vehicle, and also based on operating load of the duel fuel engine, according to an embodiment of the invention as disclosed herein;
[0017] Fig. 2 depicts a flowchart showing the steps of a method for regulating primary fuel flow to an all speed governed dual-fuel engine in at least one of a part throttle operation and a full throttle operation in a vehicle, and also based on operating load of the duel fuel engine, according to an embodiment of the invention as disclosed herein; and
[0018] Fig. 3 depicts a flowchart showing the steps of a method for restricting primary fuel flow to an all speed governed dual-fuel engine during refilling of a fuel (secondary fuel and/or primary fuel) to at least one fuel storage tank in a vehicle, according to an embodiment of the invention as disclosed herein.

DETAILED DESCRIPTION
[0019] 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.
[0020] The embodiments herein achieve a system and a method for regulating primary fuel flow to an all speed governed dual-fuel engine, which facilitates better substitution of at least a portion of primary fuel with corresponding amount of a secondary fuel to the dual-fuel engine during at least one of a part throttle operation and a full throttle operation in a vehicle, and also based on operating load of the dual-fuel engine. Further, embodiments herein achieve a system and a method for restricting primary fuel flow to a dual-fuel engine during refilling of secondary fuel to at least one secondary fuel storage tank of a vehicle. Referring now to the drawings, and more particularly to Figs. 1 through 3, where similar reference characters denote corresponding features consistently throughout the figures, there are shown embodiments.
[0021] Fig. 1 depicts a schematic view of a system 100 for regulating primary fuel flow to an all speed governed dual-fuel engine in at least one of a part throttle operation and a full throttle operation in a vehicle, and also based on operating load of the duel fuel engine, according to an embodiment of the invention as disclosed herein. In an embodiment,

the system 100 is adapted to regulate a primary fuel flow to an all speed governed dual-fuel engine (hereinafter dual-fuel engine) for better substitution of at least a portion of the primary fuel with corresponding amount of a secondary fuel flow to the dual-fuel engine during at least one of a part throttle operation and a full throttle operation in a vehicle, and also based on the operating load of the dual-fuel engine. In an embodiment, the system 100 includes an actuator 102, a controller unit 104, an engine speed sensor (not shown) and an engine exhaust temperature sensor (not shown). For the purpose of this description and ease of understanding, the system 100 for regulating primary fuel flow to the all speed governed dual-fuel engine in at least one of a part throttle operation and a full throttle operation, and also based on operating load of the duel fuel engine is explained herein with below reference to an agricultural vehicle such as tractor. However, it is also within the scope of the invention to provide the system 100 for regulating primary fuel flow to any other type of dual-fuel engine in at least one of a part throttle operation and a full throttle operation in any other type of vehicle without otherwise deterring the intended function of the system 100 as can be deduced from the description and corresponding drawings. For the purpose of this description and ease of understanding, the primary fuel provided to the duel fuel engine is at least diesel and the secondary fuel provided to the duel fuel engine is at least compressed natural gas (CNG). However, it is also within the scope of the invention to provide any of petro-diesel, bio-diesel and other fuels as primary fuel and to provide any of liquefied petroleum gas (LPG) and other fuel as secondary fuel to the duel fuel engine without otherwise deterring the intended function of the system 100 for regulating primary and secondary fuel flow to the duel fuel engine as can be deduced from the description.

[0022] In one embodiment, the actuator 102 is adapted to move a stopper means (fuel injection pump pull to stop lever, not shown in figures) of a fuel feed unit F to control the primary fuel flow to the dual-fuel engine on receiving input from the controller unit 104, where the actuator 102 is at least an electric stepper motor. However, it is also within the scope of the invention to provide any other electro-mechanical actuator, hydro-mechanical actuator or any other actuators for moving the stopper means (not shown) of the fuel feed unit F to control the primary fuel flow to the dual-fuel engine without otherwise deterring the intended function of the actuator 102 as can be deduced from the description and corresponding drawings. The fuel feed unit F is at least a fuel injection pump. The stopper means (not shown) of the fuel feed unit F is at least a stopper lever (Fuel injection pump pull to stop lever). In another embodiment, the actuator 102 is adapted to move the stopper means (not shown) of the fuel feed unit F to a closed position to restrict the primary fuel flow to the dual-fuel engine during refilling of fuel (secondary fuel and/or primary fuel) to at least one fuel storage tank of the vehicle, where the actuator 102 is at least an electric solenoid unit with plunger. However, it is also within the scope of the invention to provide any other electro-mechanical actuator, hydro-mechanical actuator or any other actuators for moving the stopper means (not shown) of the fuel feed unit F to the closed position to restrict the primary fuel flow to the dual-fuel engine during refilling of fuel (secondary fuel and/or primary fuel) to at least one fuel storage tank of the vehicle without otherwise deterring the intended function of the actuator 102 as can be deduced from the description and corresponding drawings. The actuator 102 is adapted to be movably coupled to the stopper means (not shown) of the fuel feed unit F. The actuator 102 is at least an electro¬mechanical actuator.

[0023] In an embodiment, the controller unit 104 is adapted to
control the primary fuel and second fuel flow to the dual-fuel engine based
on a least one of position of at least one throttle control means in vehicle,
operating load of the dual-fuel engine and operating speed of the dual-fuel
engine. The controller unit 104 is adapted to be provided in
communication with the actuator 102. In one embodiment, the controller unit 104 is adapted to actuate the actuator 102 which in turn moves the stopper means (not shown) of the fuel feed unit F to decrease the primary fuel flow the dual-fuel engine based on at least one of operating speed of the engine and operating load of the engine through engine speed sensor and exhaust temperatures sensor respectively. Subsequently, the controller unit 104 is adapted to actuate at least one of at least one secondary fuel control valve (not shown) and at least one secondary fuel injector (not shown) to allow secondary fuel flow to the dual-fuel engine to facilitate substitution of at least a portion of the primary fuel with corresponding amount of secondary fuel to the dual-fuel engine during at least one of a part throttle operation and a full throttle operation in the vehicle, and also based on the operating load of the engine. In another embodiment, the controller unit 104 is adapted to actuate the actuator 102 which in turn moves the stopper means (not shown) of the fuel feed unit F to the closed position to restrict the primary fuel flow to the dual-fuel engine during refilling of fuel (secondary fuel and/or primary fuel) to at least one fuel storage tank in the vehicle. The controller unit 104 is configured to receive information about at least one of operating speed of the engine and exhaust temperature through the engine speed sensor and exhaust temperature sensor respectively. The controller unit 104 is configured to receive information about engine exhaust temperature through engine exhaust temperature sensor and accordingly, the controller unit 104 determines the operating load of the engine based on the measured exhaust gas

temperature. The control unit 104 may also include or have access to
memory /databases (not shown) which include at least one of lookup tables
providing information about requirement of fuel flow at different operating
load points and engine operating speed, pre-defined exhaust temperature
values and corresponding operating load points and so on. The controller
unit 104 uses the exhaust gas temperature to calculate an operating load
point (a load point at which the engine operates). The controller unit 104
checks if the measured exhaust gas temperature is between first pre-defined
value(s) and second pre-defined value(s). The first and second pre-defined
values may be pre-defined exhaust gas temperature values. On determining
that the measured exhaust gas temperature is between the first pre-defined
value and the second pre-defined value, the controller unit 104 selects the
operating load point (a load point at which the engine operates) associated
with the combination of the first and second pre-defined values. Thus, the
operating load point can be selected based on the exhaust gas temperature.
Once the operating load point is selected, the controller unit 104 compares
the exhaust gas temperature with an ideal temperature value stored in the
look-up table (stored in the database/memory). The ideal temperature may
be the exhaust gas temperature observed during required flow of the
gaseous fuel for the calculated operating load point and the engine
operating speed. The controller unit 104 calculates a temperature
difference between the exhaust temperature and the ideal temperature. Based on the calculated temperature difference, the controller unit 104 determines the rate of flow of primary and secondary fuel to the dual-fuel engine for the calculated operating load point and the engine operating speed. In an embodiment, the controller unit 104 increases the flow of the primary fuel to the duel fuel engine on determining that the temperature difference calculated with respect to the look-up table is positive. In another embodiment, the controller unit 104 decreases the flow of the

primary fuel to the duel fuel engine on determining that the temperature difference calculated with respect to the look-up table is negative. In yet another embodiment, the controller unit 104 maintains the same flow of the primary fuel to the duel fuel engine on determining that the temperature difference computed with respect to the look-up table is zero.
[0024] The controller unit 104 is further configured to receive information about position of at least one throttle control means (hand operated throttle lever and foot operated accelerator pedal) and other operating parameters of the engine and corresponding systems present in the vehicle. The controller unit 104 is at least an electronic controller unit. In one embodiment, the controller unit 104 is a dedicated controller unit. In another embodiment, the controller unit 104 is an electronic control unit present in the vehicle.
[0025] The engine speed sensor (not shown) is used to sense the operating speed of the engine and accordingly provides the information to the controller unit 104. The engine exhaust temperature sensor (not shown) is used to sense the exhaust temperature of the engine and accordingly provides the information to the controller unit 104.
[0026] Fig. 2 depicts a flowchart showing the steps of a method 200 for regulating primary fuel flow to an all speed governed dual-fuel engine in at least one of a part throttle operation and a full throttle operation in a vehicle, and also based on operating load of the duel fuel engine, according to an embodiment of the invention as disclosed herein. For the purpose of this description and ease of understanding, the method 200 for regulating primary fuel flow to an all speed governed dual-fuel engine in at least one of a part throttle operation and a full throttle operation is explained herein below with reference to an agricultural vehicle such as tractor. However, it is also within the scope of the invention to practice/implement the entire

steps of the method 200 or with omission of at least one step of the method
200 or with any addition of at least one step to the method 200 for
regulating primary fuel flow to any other type of dual-fuel engines in at
least one of a part throttle operation and a full throttle operation in any
other type of vehicles without otherwise deterring the intended function of
the method 200 as can be deduced from the description and corresponding
drawings. In an embodiment, the method 200 includes, receiving
information by a controller unit 104 about at least one of operating speed of the dual-fuel engine and exhaust temperature of the dual-fuel engine through an engine speed sensor and an engine exhaust temperature sensor respectively (step 202), determining by the controller unit 104 about the operating load of the dual-fuel engine based on the measured engine exhaust temperature (step 203), actuating an actuator 102 through the controller unit 104 based on at least one input received by the controller unit 104 (step 204), moving a stopper means (not shown) of a fuel feed unit F through the actuator 102 to regulate the primary fuel flow to the dual-fuel engine based on at least one input received by the actuator unit 102 through the controller unit 104 (step 206) and allowing secondary fuel flow to the engine by actuating at least one of at least one secondary fuel control valve and at least one secondary fuel injector through the controller unit 104 to facilitate substitution of at least a portion of the primary fuel with corresponding amount of secondary fuel to the dual-fuel engine during at least one of a part throttle operation and a full throttle operation and also based on the operating load of the dual-fuel engine (step 208).
[0027] Fig. 3 depicts a flowchart showing the steps of a method 300 for restricting primary fuel flow to an all speed governed dual-fuel engine during refilling of fuel (secondary fuel and/or primary fuel) to at least one fuel storage tank in a vehicle, according to an embodiment of the invention as disclosed herein. For the purpose of this description and ease of

understanding, the method 300 for restricting primary fuel flow to an all
speed governed dual-fuel engine during refilling of fuel (secondary fuel
and/or primary fuel) to at least one fuel storage tank in a vehicle is
explained herein below with reference to an agricultural vehicle such as
tractor. However, it is also within the scope of the invention to
practice/implement the entire steps of the method 300 or with omission of
at least one step of the method 300 or with any addition of at least one step
to the method 300 for restricting primary fuel flow to any other type of
dual-fuel engines during refilling of fuel (secondary fuel and/or primary
fuel) to at least one fuel storage tank in any other type of vehicles without
otherwise deterring the intended function of the method 300 as can be
deduced from the description and corresponding drawings. In an
embodiment, the method 300 includes, actuating an actuator 102 through a controller unit 104 based on at least one input received by the controller unit 104 (step 302) and moving a stopper means (not shown) of a fuel feed unit F to a closed position through the actuator 102 to restrict the primary fuel flow to the dual-fuel engine during refilling of fuel (secondary fuel and/or primary fuel) to at least one fuel storage tank based on at least one input received by the actuator unit 102 through the controller unit 104 (step 304).
[0028] Therefore, a system 100 and a method 200 for regulating primary fuel flow to an all speed governed dual-fuel engine for better substitution of at least a portion of the primary fuel with corresponding amount of a secondary fuel to the dual-fuel engine during at least one of a part throttle operation and a full throttle operation in a vehicle, and also based on operating load of the duel fuel engine is provided. Further, a system (100) and a method (300) for restricting primary fuel flow to an all speed governed dual-fuel engine during refilling of fuel (secondary fuel

and/or primary fuel) to at least one fuel storage tank in the vehicle is provided.
[0029] 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 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 system 100 for regulating primary fuel flow to a dual fuel engine in
at least one of a part throttle operation and a full throttle operation in a
vehicle, said system 100 comprising:
an actuator 102 adapted to be movably coupled to a stopper means of a fuel feed unit F; and
a controller unit 104 adapted to be provided in communication with said actuator 102,
wherein
said actuator 102 is adapted to move the stopper means of the fuel feed unit F to regulate the primary fuel flow to the dual-fuel engine based on the input received from said controller unit 104, and a secondary fuel is provided to the dual-fuel engine to facilitate substitution of at least a portion of the primary fuel with corresponding amount of secondary fuel to the dual-fuel engine during at least one of the part throttle operation and the full throttle operation.
2. The system 100 as claimed in claim 1, wherein said controller unit 104
is configured to:
receive information about at least one of operating speed of the engine and exhaust temperature of engine through said engine speed sensor and an engine exhaust temperature sensor respectively;
determine operating load of the dual-fuel engine based on the measured engine exhaust temperature;
actuate said actuator 102 which in turn moves the stopper means of the fuel feed unit F to regulate the primary fuel flow to the dual-fuel

engine based on at least one of operating speed of the engine and exhaust temperature of engine and operating load of the engine; and
actuate at least one of at least one secondary fuel control valve and at least one secondary fuel injector to allow secondary fuel flow to the dual-fuel engine to facilitate substitution of at least a portion of the primary fuel with corresponding amount of secondary fuel flow to the dual-fuel engine during at least one the part throttle operation and the full throttle operation, and based on operating load of the duel fuel engine.
3. The system 100 as claimed in claim 2, wherein
said actuator 102 is adapted to move the stopper means of the fuel feed unit F to decrease the primary fuel flow to the dual-fuel engine based on the input received from said controller unit 104; and
said controller unit 104 is adapted to actuate at least one of at least one secondary fuel control valve and at least one secondary fuel injector to allow secondary fuel flow to the dual-fuel engine to facilitate substitution of at least a portion of the primary fuel with corresponding amount of secondary fuel flow to the dual-fuel engine during at least one of the part throttle operation and the full throttle operation, and based on operating load of the engine.
4. The system 100 as claimed in claim 3, wherein said actuator 102 is at
least one of an electric stepper motor and an electro-mechanical
actuator;
said controller unit 104 is at least an electronic controller unit;
the fuel feed unit F is at least a fuel injection pump; and

the stopper means of the fuel feed unit F is at least a fuel injection pump pull to stop lever.
5. A method 200 for regulating primary fuel flow to a dual-fuel engine in
at least one of a part throttle operation and a full throttle operation in a
vehicle, said method 200 comprising:
actuating an actuator 102 through a controller unit 104 based on at least one input received by the controller unit 104; and
moving a stopper means of a fuel feed unit F through the actuator 102 to regulate the primary fuel flow to the dual-fuel engine based on the input
received by the actuator unit 102 through the controller unit 104; and
allowing secondary fuel flow to the engine by actuating at least one of at least one secondary fuel control valve and at least one secondary fuel injector through the controller unit 104 to facilitate substitution of at least a portion of the primary fuel with corresponding amount of secondary fuel flow to the dual-fuel engine during at least one of the part throttle operation and the full throttle operation.
6. The method 200 as claimed in claim 5 comprising,
determining by the controller unit 104 about the operating load of the dual-fuel engine based on the measured engine exhaust temperature prior to said actuating the actuator 102 through the controller unit 104 based on at least one input received by the controller unit 104.
7. The method 200 as claimed in claim 6 comprising,
receiving information by the controller unit 104 about at least one of the position of at least one operating speed of the dual-fuel engine and

exhaust temperature of the dual-fuel engine through an engine speed sensor and an engine exhaust temperature sensor respectively prior to said determining by the controller unit 104 about the operating load of the dual-fuel engine based on the measured engine exhaust temperature.
8. A controller unit 104 for a vehicle, said controller unit 104 is
configured to:
receive information about at least one of operating speed of the engine and exhaust temperature of engine through said engine speed sensor and an engine exhaust temperature sensor respectively;
determine operating load of the dual-fuel engine based on the measured engine exhaust temperature;
actuate said actuator 102 which in turn moves the stopper means of the fuel feed unit F to regulate the primary fuel flow to the dual-fuel engine based on at least one of operating speed of the engine and exhaust temperature of engine and operating load of the engine; and
actuate at least one of at least one secondary fuel control valve and at least one secondary fuel injector to allow secondary fuel flow to the dual-fuel engine to facilitate substitution of at least a portion of the primary fuel with corresponding amount of secondary fuel flow to the dual-fuel engine during at least one the part throttle operation and the full throttle operation, and based on operating load of the duel fuel engine.
9. A system 100 for restricting primary fuel flow to a dual-fuel engine
during refilling of fuel to at least one fuel storage tank in a vehicle, said
system 100 comprising:
an actuator 102 adapted to be movably coupled to a stopper means of a fuel feed unit F; and

a controller unit 104 adapted to be provided in communication with said actuator 102,
wherein
said actuator 102 is adapted to move the stopper means of the fuel feed unit F to a closed position to restrict the primary fuel flow to the dual-fuel engine based on the input received from said controller unit 104 during refilling of fuel to at least one fuel storage tank.
10. The system 100 as claimed in claim 9, wherein said actuator 102 is at
least one of an electric solenoid unit with plunger and an electro¬
mechanical actuator;
said controller unit 104 is at least an electronic controller unit;
the fuel feed unit F is at least a fuel injection pump;
the stopper means of the fuel feed unit F is at least a fuel injection pump pull to stop lever.
11. A method 300 for restricting primary fuel flow to a dual-fuel engine
during refilling of fuel to at least one fuel storage tank in a vehicle, said
method 300 comprising:
actuating an actuator 102 through a controller unit 104 based on at least one input received by the controller unit 104; and

moving a stopper means of a fuel feed unit F to a closed position through the actuator 102 to restrict the primary fuel flow to the dual-fuel engine during refilling of fuel to at least one fuel storage tank based on at least one input received by the actuator unit 102 through the controller unit 104.