TECHNICAL FIELD
The embodiments herein generally relate to duel fuel engines and more particularly, to a system and a method for regulating primary fuel flow to a duel fuel engine for better substitution of at least a portion of primary fuel with corresponding amount of a secondary fuel to the duel fuel engine during at least a part throttle operation in a vehicle.
BACKGROUND
Duel fuel engine is a type of engine which combusts two different types of fuels to reduce emissions and improve operating economy. 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 duel 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 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] Therefore, there exists a need for a system (fuel control system) and a method for regulating primary fuel flow to a duel fuel engine for better substitution of at least a portion of primary fuel with corresponding amount of a secondary fuel to the duel fuel engine during at least a part throttle operation in a vehicle, which obviates the aforementioned drawbacks.
OBJECTS
[006] 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 duel fuel engine, which facilitates better substitution of at least a portion of primary fuel with corresponding amount of a secondary fuel to the duel fuel engine during at least a part throttle operation in a vehicle.
[007] Another object of an embodiment of this invention is to provide a method for regulating primary fuel flow to an all speed governed duel fuel engine, which facilitates better substitution of at least a portion of primary fuel with corresponding amount of a secondary fuel to the duel fuel engine during at least a part throttle operation in a vehicle.

[008] 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 duel fuel engine in at least a part throttle operation in a vehicle, which reduces emission, improves substitution of primary fuel, improves overall fuel economy and improves operating economy.
[009] 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 duel fuel engine and increasing secondary fuel flow to the duel fuel engine to reduce emissions during at least a part throttle operation in a vehicle.
[0010] 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
[0011] 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:
[0012] Fig. 1 depicts a schematic view of a system for regulating primary fuel flow to an all speed governed duel fuel engine in at least a part

throttle operation in a vehicle, according to an embodiment of the invention as disclosed herein; and
[0013] Fig. 2 depicts a flowchart showing the steps of a method for regulating primary fuel flow to an all speed governed duel fuel engine in at least a part throttle operation in a vehicle, according to an embodiment of the invention as disclosed herein.

DETAILED DESCRIPTION
[0014] The embodiments herein and the various features and advantageous details thereof are explained more fully with reference to the non-limiting embodiments that are illustrated in the accompanying drawings and detailed in the following description. Descriptions of well-known components and processing techniques are omitted so as to not unnecessarily obscure the embodiments herein. The examples used herein are intended merely to facilitate an understanding of ways in which the embodiments herein may be practiced and to further enable those of skill in the art to practice the embodiments herein. Accordingly, the examples should not be construed as limiting the scope of the embodiments herein.
[0015] The embodiments herein achieve a system and a method for regulating primary fuel flow to an all speed governed duel fuel engine, which facilitates better substitution of at least a portion of primary fuel with corresponding amount of a secondary fuel to the duel fuel engine during at least a part throttle operation in a vehicle. Referring now to the drawings, and more particularly to Figs. 1 through 2, where similar reference characters denote corresponding features consistently throughout the figures, there are shown embodiments.
[0016] Fig. 1 depicts a schematic view of a system 100 for regulating primary fuel flow to an all speed governed duel fuel engine in at least a part throttle operation in a vehicle, 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 duel fuel engine (hereinafter duel fuel engine) for better substitution of at least a portion of the primary fuel with corresponding amount of a secondary fuel flow to the duel fuel engine during at least a part throttle operation in a vehicle. In an embodiment, the system 100 includes an actuator 102, a

controller unit 104, a throttle position sensor 106 and an engine speed 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 duel fuel engine in at least a part throttle operation 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 duel fuel engine in at least a part 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 and corresponding drawings.
[0017] In an embodiment, the actuator 102 is adapted to move a control means (not shown) of a fuel feed unit F to control the primary fuel flow to the duel fuel engine on receiving input from the controller unit 104. The actuator 102 is adapted to be movably coupled to the control means (not shown) of the fuel feed unit F. The actuator 102 is at least an electro-mechanical actuator. The fuel feed unit F is at least a fuel injection pump in the vehicle. The control means (not shown) of the fuel feed unit F is at least a fuel injection pump lever.
[0018] In an embodiment, the controller unit 104 is adapted to control the primary fuel and second fuel flow to the duel fuel engine based

on the position of at least one throttle control means (not shown) and
operating speed of the duel fuel engine through throttle position sensor 106
and engine speed sensor respectively. The controller unit 104 is adapted to
be provided in communication with the actuator 102. The controller unit
104 is adapted to actuate the actuator 102 which in turn moves the control
means (not shown) of the fuel feed unit F to decrease the primary fuel flow
the duel fuel engine based on at least one of operating speed of the engine,
and the throttle position of at least one throttle control means (not shown).
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 duel
fuel engine to facilitate substitution of at least a portion of the primary fuel
with corresponding amount of secondary fuel flow to the duel fuel engine
during at least a part throttle operation in the vehicle. The controller unit
104 is configured to receive information about at least one of a position of
at least one throttle control means (not shown) through the throttle position
sensor 106 and operating speed of the engine through engine speed sensor
(not shown). The controller unit 104 is further configured to receive
information about operating load of the engine and other operating
parameters of the engine and corresponding systems 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.
[0019] The throttle position sensor 106 is adapted to sense a position (throttle demand by user of the vehicle and/or accelerator pedal input) of at least one throttle control means (not shown) of the vehicle and accordingly provides an output signal to the controller unit 104. The throttle control means (not shown) is at least one of a hand operated throttle

control means (throttle control lever) and a foot operated throttle pedal (accelerator pedal). The engine speed sensor (not shown) is used to sense the operating speed of the engine and accordingly provide the information to the controller unit 104.
[0020] Fig. 2 depicts a flowchart showing the steps of a method 200
for regulating primary fuel flow to an all speed governed duel fuel engine
in at least a part throttle operation, 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 duel fuel engine in at least a part 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 duel fuel engines in at least a part 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 for regulating primary fuel flow to an all speed governed duel fuel engine in at least a part throttle operation includes, receiving information by a controller unit 104 about at least one of the position of at least one throttle control means (not shown) and operating speed of the duel fuel engine through a throttle position sensor 106 and an engine speed sensor respectively (step 202), actuating an actuator 102 through the controller unit 104 based on at least one input received by the controller unit 104 (step 204) and moving a control means (not shown) of a fuel feed unit F through the actuator 102 to regulate the primary fuel flow to the duel 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 the secondary fuel flow to the duel fuel engine during at least a part throttle operation in the vehicle.
[0021] Therefore, a system 100 and a method 200 for regulating primary fuel flow to an all speed governed duel fuel engine for better substitution of at least a portion of the primary fuel with corresponding amount of a secondary fuel to the duel fuel engine during at least a part throttle operation in a vehicle is provided.
[0022] 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 duel fuel engine in
at least a part throttle operation in a vehicle, said system 100
comprising:
an actuator 102 adapted to be movably coupled to a control 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 control means of the fuel feed unit F to regulate the primary fuel flow to the duel fuel engine based on the input received from said controller unit 104, and a secondary fuel is provided to the duel fuel engine to facilitate substitution of at least a portion of the primary fuel with corresponding amount of secondary fuel to the duel fuel engine during at least the part throttle operation.
2. The system 100 as claimed in claim 1 comprising a throttle position sensor 106 adapted to sense a position of at least one throttle control means of the vehicle and accordingly provides an output signal to said controller unit 104.
3. The system 100 as claimed in claim 2, wherein said controller unit 104 is configured to:
receive information about at least one of the position of at least one throttle control means and operating speed of the engine through said throttle position sensor 106 and an engine speed sensor respectively; and

actuate said actuator 102 which in turn moves the control means of the fuel feed unit F to regulate the primary fuel flow to the duel fuel engine based on at least one of an operating speed of the duel fuel engine and the throttle position of at least one throttle control means is at least at the part throttle position; 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 duel fuel engine to facilitate substitution of at least a portion of the primary fuel with corresponding amount of the secondary fuel flow to the duel fuel engine during at least the part throttle operation.
4. The system 100 as claimed in claim 3, wherein
said actuator 102 is adapted to move the control means of the fuel feed unit F to decrease the primary fuel flow to the duel 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 duel fuel engine to facilitate substitution of at least a portion of the primary fuel with corresponding amount of the secondary fuel flow to the duel fuel engine during at least the part throttle operation.
5. The system 100 as claimed in claim 4, wherein said actuator 102 is at
least 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 control means of the fuel feed unit F is at least a lever; and

the throttle control means is at least one of a foot operated throttle control means and a hand operated throttle control means.
6. A method 200 for regulating primary fuel flow to a duel fuel engine in
at least a part 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 control means of a fuel feed unit F through the actuator 102 to regulate the primary fuel flow to the duel 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 the secondary fuel flow to the duel fuel engine during at least the part throttle operation.
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 throttle control means and operating speed of the duel fuel engine through a throttle position sensor 106 and an engine speed sensor respectively prior to said actuating an actuator 102 through a controller unit 104 based on at least one input received by the controller unit 104.

8. A controller unit 104 for a vehicle, said controller unit 104 is configured to:
receive information about at least one of the position of at least one throttle control means and operating speed of the engine through said throttle position sensor 106 and an engine speed sensor respectively; and
actuate said actuator 102 which in turn moves the control means of the fuel feed unit F to regulate the primary fuel flow to the duel fuel engine based on at least one of an operating speed of the duel fuel engine and the throttle position of at least one throttle control means is at least at a part throttle position; 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 duel fuel engine to facilitate substitution of at least a portion of the primary fuel with corresponding amount of the secondary fuel flow to the duel fuel engine during at least a part throttle operation.