The present invention relates to a diesel engine. More particularly, the present
invention relates to enhancing efficiency of the diesel engine of a vehicle.
BACKGROUND
[002] Background description includes information that may be useful in
understanding the present invention. It is not an admission that any of the information provided herein is prior art or relevant to the present invention, or that any publication specifically or implicitly referenced is prior art.
[003] An internal combustion engine is generally a four-stroke engine in which
piston completes four strokes, i.e. suction, compression, expansion, and exhaust while
rotating crankshaft. Intake or suction stroke begins at top dead centre (T.D.C.) and ends at
bottom dead centre (B.D.C), intake valve must be in open position while piston sucks air into
a cylinder by its downward movement. As piston lowers down air is being sucked by
downward movement against the piston. Compression stroke, starts at the B.D.C, and
terminates at the T.D.C, the piston compresses air, intake and exhaust valves are closed in
position during the compression stroke. Just before the end of compression stroke diesel fuel
is injected into the cylinder which is immediately ignited due to heat generated by
compression of the air. In expansion or power stroke, the piston in a diesel engine is at the
T.D.C compelling the piston to return to the B.D.C. Expansion stroke produces mechanical
work from the engine to turn the crankshaft, therefore also known as power stroke. During
exhaust stroke, exhaust valve is opened, the piston comes from the B.D.C. to the T.D.C,
thereby removing exhaust gases outside the vehicle through silencer unit.
[004] Since during running of vehicle engine, lot of heat energy goes as waste at
various points, this heat needs to be captured from selected pick-up points for reusing it in the engine. In this regard, two important modes have been considered viz.(i)to recover/conserve heat by redesign of silencer in order to utilise it back in the engine. This is achievedby preheating of incoming diesel fuel in the pipelines going to the engine by routing them through the silencer thereby a lot of heat of hot exhaust gases coming out from the engine is utilised and (ii) to keep advance of fuel injection at an optimum value, so that heat loss to the coolant is minimum 'Reduction of fuel injection advance' is another facility which is

required in conjunction with redesigned silencer, as a must, to further increase engine efficiency. As said above, when hot fuel coming via new silencer is injected into the engine cylinder, it evaporates hotter and is then ignited to still higher temp. Due to which there is produced more back pressure towards the end of the compression stroke which retards piston motion. In order that this should create an obstruction of least duration to piston motion, and also to avoid any resulting knocking, advance of fuel injection is to be kept minimum. Therefore, the whole story starting from start of fuel injection to end of complete combustion would be over through the least degree of advance. This further contributes to efficiency by conserving heat as time to lose heat to cooling water is reduced.
[005] There is, therefore a need in the art to provide a fuel pre-heating system that
can be concluded from the above that in spite of all the efforts made, the solutions previously proposed and known in the prior art do not meet all the essential requirements which are taken into consideration in the present invention.
OBJECTS OF THE PRESENT DISCLOSURE
[006] It is an object of the present invention to provide a fuel pre-heating system of
vehicle.
[007] It is another object of the present invention to provide a fuel pre-heating
system of vehicle for increasing engine efficiency.
[008] It is yet another object of the present invention to provide a fuel pre-heating
system of vehicle to decrease thermal losses, increase engine power, and complete
combustion of fuel.
[009] It is another object of the present invention to provide a fuel pre-heating
system of vehicle by utilising waste heat energy of engine's exhaust.
[0010] It is yet another object of the present invention to provide a fuel pre-heating
system of vehicle to decrease fuel consumption of engine.
SUMMARY
[0011] The present invention relates to a diesel engine. More particularly, the present
invention relates to enhancing efficiency of the diesel engine of a vehicle.
[0012] According to an aspect, the present disclosure provides a fuel pre-heating
system for a vehicle, said system comprising: a silencer unit attached to an engine of the vehicle to receive exhaust gases from the engine; a fuel pipe, made of thermally conductive material, to carry fuel from a fuel tank to the engine, wherein the fuel pipe is looped through

the silencer unit such that the exhaust gases flow around the fuel pipe to heat the fuel flowing
in the fuel pipe to increase temperature of the flowing fuel. This acts this way, hot diesel fuel
coming through silencer enters engine cylinder, evaporates faster to a higher temp. Vapours
towards the end of compression stroke. On account of heat of compression, combustion of
these hot fuel vapours shall take place and higher temp, (then with original silencer) shall be
developed. This results finally in higher pressure inside engine cylinder, means more force
on piston and so enhanced power of engine. Thus there shall be input of saved energy to
engine leading to increased efficiency of the engine.
[0013] In an aspect, a bifurcater is positioned inside the silencer unit to enable
bifurcation of the exhaust gases along the fuel pipe for increasing heat transfer to the fuel
pipe from the exhaust gases.
[0014] In an aspect, the thermally conductive material is selected from a group
comprising of a copper and aluminium.
[0015] In an aspect, external surface of the silencer unit is lined with thermally
insulating material to prevent loss of heat to the environment.
[0016] In an aspect, joints of the fuel pipe are configured as a part of the silencer unit.
[0017] In an aspect, a heatproof gasket is used to join the silencer unit and exhaust of
the engine.
[0018] In order to best utilize the fuel power, the injected fuel should have finished
with the complete combustion just before start of power stroke. Hence, just before the end of
compression stroke preceding power stroke, the fuel -
1. should have been fully injected at the right deg. of advance.
2. should have evaporated totally, and
3. should have burnt out to 100%, in order to be in readiness to release power in the power stroke following it.
[0019] To use above principle for designing advance changing mechanism.
'Reduction of fuel injection advance' is another facility which is required in conjunction with a redesigned silencer, as a must, to further increase engine efficiency. As said above, when hot fuel coming via new silencer is injected into the engine cylinder, it evaporates hotter and is then ignited to still higher temp. Due to which there is produced more back pressure towards the end of the compression stroke which retards piston motion. In order that this should create an obstruction of least duration to piston motion, and also to avoid any resulting knocking, advance of fuel injection is to be kept minimum. Therefore, the whole story starting from start of fuel injection to end of complete combustion (as stated above in points

(1) (2) (3) above) would be over through the least degree of advance. This further contributes
to efficiency by conserving heat as time to lose heat to cooling water is reduced.
[0020] In an aspect, a device is positioned proximal to the engine, the device
comprising: an upper disc coupled to a plunger of a fuel pump on an outer side of the upper disc; and a lower disc is fixed with the upper disc, and coupled to a timing gear on its outer side, wherein the timing gear is configured to rotate the lower disc relative to the upper disc to control operation of the feed pump for optimum advance angle. In an aspect, the upper disc is inscribed with a pointer, and wherein the loser disc is inscribed with angular marks for determination of angular rotation of the upper disc and the lower disc with respect to each other.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] The accompanying drawings are included to provide a further understanding
of the present disclosure, and are incorporated in and constitute a part of this specification.
The drawings illustrate exemplary embodiments of the present disclosure and, together with
the description, serve to explain the principles of the present disclosure. The diagrams are for
illustration only, which thus is not a limitation of the present disclosure.
[0022] FIG. 1A illustrates an exemplary a cross-sectional view representation of a
silencer unit, in accordance with an embodiment of the present disclosure.
[0023] FIG. IB illustrates an exemplary representation of fuel pipe, in accordance
with an exemplary embodiment of the disclosure.
[0024] FIG. 2A illustrates an exemplary front view representation of a device for
advance changing mechanism, in accordance with an embodiment of the present disclosure.
[0025] FIG. 2B illustrates an exemplary top view representation of a device advance
changing mechanism, in accordance with an embodiment of the present disclosure.
[0026] FIG. 2C illustrates an exemplary front view representation of a device for
advance changing mechanism with markings, in accordance with an embodiment of the
present disclosure.
DETAILED DESCRIPTION
[0027] The following is a detailed description of embodiments of the disclosure
depicted in the accompanying drawings. The embodiments are in such detail as to clearly communicate the disclosure. However, the amount of detail offered 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.
[0028] In the following description, numerous specific details are set forth in order to
provide a thorough understanding of embodiments of the present invention. It will be apparent to one skilled in the art that embodiments of the present invention may be practised without some of these specific details.
[0029] Embodiments of the present invention include various steps, which will be
described below. The steps may be performed by hardware components or may be embodied in machine-executable instructions, which may be used to cause a general-purpose or special-purpose processor programmed with the instructions to perform the steps. Alternatively, steps may be performed by a combination of hardware, software, and firmware and/or by human operators.
[0030] If the specification states a component or feature "may", "can", "could", or
"might" be included or have a characteristic, that particular component or feature is not required to be included or have the characteristic.
[0031] As used in the description herein and throughout the claims that follow, the
meaning of "a," "an," and "the" includes plural reference unless the context clearly dictates otherwise. Also, as used in the description herein, the meaning of "in" includes "in" and "on" unless the context clearly dictates otherwise.
[0032] Each of the appended claims defines a separate invention, which for
infringement purposes is recognised as including equivalents to the various elements or limitations specified in the claims. Depending on the context, all references below to the "invention" may in some cases refer to certain specific embodiments only. In other cases, it will be recognised that references to the "invention" will refer to subject matter recited in one or more, but not necessarily all, of the claims.
[0033] All methods described herein may be performed in any suitable order unless
otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g., "such as") provided with respect to certain embodiments herein is intended merely to better illuminate the invention and does not pose a limitation on the scope of the invention otherwise claimed. No language in the specification should be construed as indicating any non-claimed element essential to the practice of the invention.
[0034] Various terms as used herein are shown below. To the extent a term used in a
claim is not defined below, it should be given the broadest definition persons in the pertinent

art have given that term as reflected in printed publications and issued patents at the time of
filing.
[0035] As per the disclosed in the background section, the present invention relates to
a diesel engine. More particularly, the present invention relates to enhancing efficiency of the
diesel engine of a vehicle.
[0036] According to an aspect, the present disclosure provides A fuel pre-heating
system for a vehicle, said system comprising: a silencer unit attached to an engine of the
vehicle to receive exhaust gases from the engine; a fuel pipe, made of thermally conductive
material, to carry fuel from a fuel tank to the engine, wherein the fuel pipe is looped through
the silencer unit such that the exhaust gases flow around the fuel pipe to heat the fuel flowing
in the fuel pipe to increase temperature of the flowing fuel.
[0037] In an aspect, a bifurcater is positioned inside the silencer unit to enable
bifurcation of the exhaust gases along the fuel pipe for increasing heat transfer to the fuel
pipe from the exhaust gases.
[0038] In an aspect, the thermally conductive material is selected from a group
comprising of a copper and aluminium.
[0039] In an aspect, external surface of the silencer unit is lined with thermally
insulating material to prevent loss of heat to the environment.
[0040] In an aspect, joints of the fuel pipe are configured as a part of the silencer unit.
[0041] In an aspect, a heatproof gasket is used to join the silencer unit and exhaust of
the engine.
[0042] In an aspect, 'Reduction of fuel injection advance' is another facility which is
required in conjunction with a redesigned silencer, as a must, to further increase engine
efficiency. As said above, when hot fuel coming via new silencer is injected into the engine
cylinder, it evaporates hotter and is then ignited to still higher temp. Due to which there is
produced more back pressure towards the end of the compression stroke which retards piston
motion. In order that this should create an obstruction of least duration to piston motion, and
also to avoid any resulting knocking, advance of fuel injection is to be kept minimum.
Therefore the whole story starting from start of fuel injection to end of complete combustion
would be over through the least degree of advance. This further contributes to efficiency by
conserving heat as time to lose heat to cooling water is reduced.
[0043] In an aspect, a device is positioned proximal to the engine, the device
comprising: an upper disc coupled to a plunger of a fuel pump on an outer side of the upper
disc; and a lower disc is fixed with the upper disc, and coupled to a timing gear on its outer

side, wherein the timing gear is configured to rotate the lower disc relative to the upper disc to control operation of the feed pump for optimum advance angle. In an aspect, the upper disc is inscribed with a pointer, and wherein the loser disc is inscribed with angular marks for determination of angular rotation of the upper disc and the lower disc with respect to each other.
[0044] FIG. 1A illustrates an exemplary representation of a cross-sectional view of a
silencer unit 100 in accordance with an embodiment of the present disclosure.
[0045] In an embodiment, a fuel preheating system can include a silencer unit 100.
The silencer unit 100 can be configured with engine of the vehicle to receive exhaust gases 102. The silencer unit 100 can have an inlet 102 to receive the exhaust gases of the engine and further discharges exhaust gases 102 to ambient atmosphere through an outlet in the silencer unit 100. The silencer unit 100 further comprises a fuel pipe 104. The fuel pipe 104 can carry fuel from a fuel tank to the engine, said fuel pipe 104 can be looped through the silencer unit 100 using a set of clamps 108 fitted with the silencer unit 100, and positioned inside the silencer unit 100.
[0046] Further, the silencer unit 100 includes a bifurcater 110. The bifurcater 110 can
be configured at centre of the silencer unit 100 to bifurcate the exhaust gases to facilitate enhancement of heat transfer from the exhaust gases to the flowing fuel in the fuel pipe 104. It would be appreciated by the person skilled in the art that since the silencer unit 100 is located proximal to the engine, therefore, heat energy of the exhaust gases 102 is utilised efficiently.
[0047] In an embodiment, outer surface of the silencer unit 100 can be lined with a
thermally insulating material that includes but not limiting only to tantalum carbide, hafnium carbide. It would be appreciated by the person skilled in the art that thermally insulating the silencer unit 100 can prevent heat being dissipated to the atmosphere.
[0048] In an embodiment, the fuel pipe 104 can be configured with the inner surface
of the silencer unit 100. Further, the bifurcater 110 can be positioned at the centre of the silencer unit 100 to bifurcate the exhaust gases from the engine. Therefore, the bifurcated exhaust gases are directed towards the fuel pipe 104 to facilitate efficient heat transfer to the exhaust gases from the fuel flowing through the fuel pipe 104. The bifurcater 110 can be made from two steel sheets joined together in a hollow shape with closed ends. The bifurcater 110 enables bifurcation of the exhaust gases 102along the fuel pipe 104 for increasing heat transfer to the fuel pipe 104from the exhaust gases 102. In another embodiment, the bifurcater 110 can be kept clear of fuel pipe 104 using the set of clams 108, said bifurcater

110 can have supports at Vi, V2,3A part of its length and can be tack welded with the silencer
unit 100.
[0049] FIG. IB illustrates loops of fuel pipelines in accordance with an exemplary
embodiment of the disclosure.
[0050] In an embodiment, the fuel pipe 104 can be made from heat-conducting
material such as but not limited to copper, and aluminium enables maximum heat transfer
from the exhaust gases 102 and the fuel carrying in the fuel pipe 104. In an embodiment, a
part of the fuel pipe 104 inside the silencer unit 100 gets longer due to loops of the fuel pipe
104 inside the silencer unit 100. In an embodiment, as the fuel pipe 104 portion inside the
silencer gets longer due to loops inside the silencer, will give rise to extra fluid friction, thus
retarding the fluid flow. To account for the same or to have an even better flow of the fuel,
inner diameter of the copper pipes can be increased to almost 2-3 times. In an exemplary
embodiment, for better heat transfer to the fuel pipe 104 inside the silencer unit 100 are to be
of a material like copper which is a very good conductor of heat.
[0051] In an exemplary embodiment, various calculations were performed to verify
the results, which can be as follows: -
CALCULATIONS SHOWING INCREASE IN EFFICIENCY OF DIESEL ENGINE
Assumptions: -
1. 10 % heat lost to cooling and operating mechanisms-
2. Balance heat left for work conversion= 100-10=90%
[0052] Therefore, taking efficiency as 40 %, work % converted is- =90 X40/100=36%
[0053] Heat going as waste=90-36=54%
1. Increase in efficiency with heat recovery
SCENARIO 1-
[0054] Assuming heat recovery is 40%,
[0055] efficiency increase is=54X40X36/100X90=9%
SCENARIO 2-
[0056] Assuming heat recovery is 50%,
[0057] efficiency increase is=54X50X36/100X90=l 1%
SCENARIO 3-
[0058] Assuming heat recovery is 60%,
[0059] efficiency increase is=54X60X36/100X90=13%
2. Increase in efficiency with advance reduction
[0060] Approx. 2-3 % (empirical)

3. Overall increase in efficiency=13+2=15 % max.
[0061] FIG. 2A through 2C illustrate exemplary representations of a device 200 for
advance changing mechanism, in accordance with an embodiment of the present disclosure.
[0062] In order to best utilize the fuel power, the injected fuel should have finished
with the complete combustion just before start of power stroke. Hence just before the end of compression stroke preceding power stroke, the fuel -
1. should have been fully injected at the right deg. of advance.
2. should have evaporated totally, and
3. should have burnt out to 100%, in order to be in readiness to release power in the power stroke following it.
[0063] To use above principle for designing of advance changing mechanism. We
will find that due to ignition of vapours of the pre-heated fuel injected in the engine cylinder, when there is produced more back pressure towards the end of compression stroke, an additional force is required to overcome compression. Therefore, in order that this should create obstruction of least duration to piston motion, and also to avoid any resulting knocking, advance of fuel injection is to be kept minimum. Now the whole story starting from start of fuel injection to end of complete combustion as counted in 3 steps above would be over through the least degree of advance. This further enhances the efficiency by conserving heat as time to lose heat to coolant is reduced.
[0064] Caution - to provide additional force required by 'compression', an additional
weight of flywheel might be necessary for smooth operation.
[0065] By using redesigned silencer in conjunction, the least advance is required to be
worked out by trial. In case there is provision in the design of the fuel injection system of the vehicle to alter the advance, proceed this way: -
[0066] Reduce the advance in steps of 1/2°-l°. The engine speed will increase. Further,
reduce the advance in small steps till the speed stops increasing. Come back to the last point of maximum speed. This corresponds to the required optimum advance. Conserving heat by having least advance contributes to efficiency by approx. 2-3 %. In case the advance changing mechanism is not provided in the purchaser's system, its design can be worked out by obtaining design data of all parts connected to fuel feed-pump from them, i.e. as to how and where this mechanism exactly fits in the locations of timing gear, accelerator, fuel feed pump proper and any other parts connected thereto. For exact design, construction details of all these related parts would be required.

[0067] In an embodiment, a device for advance changing mechanism 200 can include
any or a combination of an upper disc 202, and a lower disc 204 positioned proximal to the engine providing optimum fuel advance with the help of advance changing mechanism. The upper disc 202 can be inscribed with pointer at the outer diameter, said upper disc 202 is coupled with a plunger 206 of fuel pump. The lower disc 204 can be inscribed with angle markings 212 at its outer edge, said lower disc 204 is coupled with timing gear 208. The upper disc 202 mark can be bolted through oval holes 212 at a required angle with lower disc 204 enabling angular shifts for inscribed angles. The timing gear can be configured with the fuel pump enabling required optimum fuel advance from the fuel pump, thereby increasing the fuel efficiency of the engine.
[0068] In an alternate embodiment, the device for advance changing mechanism is not
provided in the purchaser's system, its design can be worked out by obtaining design data of all parts connected to fuel feed-pump from them i.e. as to how and where this mechanism exactly fits in the locations of timing gear, accelerator, fuel feed pump proper and any other parts connected thereto. For exact design, construction details of all these related parts would be required.
[0069] In an embodiment, the device for advance change mechanism 200 can include
2 discs (comprising the upper disc 202 and the lower disc 204) acting as flanges of a coupling
which shall have a relative position with respect to each other. The upper disc 202 can be
coupled with the plunger of the fuel feed pump. The upper disc 202 can have a pointer at its
outermost diameter. The angular shift changes advance. In case of a multi-cylinder engine,
the upper disc 202 shall be joined to the corresponding part common to all the plungers.
[0070] In an embodiment, the lower disc 204 can be coupled to the timing gear side.
The lower disc 204 shall have advance angles marked like 12°-10o-8o-6o-4o-2o-0° in a sector of say 12° (to match reducing advance). To reduce the advance, the upper disc mark shall be matched with the required degree of the lower disc 204 and both the discs 202. 204 shall be tightened with bolts 210 on 2 opposite sides passing through oval holes which are cut in the upper disc 202 for exact positioning of upper disc mark. The new advance can be matched this way by moving the mark in the direction of reducing advance.
[0071] While the foregoing describes various embodiments of the invention, other and
further embodiments of the invention may be devised without departing from the basic scope thereof. The scope of the invention is determined by the claims that follow. The invention is not limited to the described embodiments, versions or examples, which are included to enable

a person having ordinary skill in the art to make and use the invention when combined with information and knowledge available to the person having ordinary skill in the art.
ADVANTAGES OF THE PRESENT DISCLOSURE
[0072] The present disclosure provides a fuel pre-heating system of vehicle.
[0073] The present disclosure provides a fuel pre-heating system of vehicle for
increasing engine efficiency.
[0074] The present disclosure provides a fuel pre-heating system of vehicle to
decrease thermal losses, increase engine power, and complete combustion of fuel.
[0075] The present disclosure provides a fuel pre-heating system of vehicle by
utilising waste heat energy of engine's exhaust.
[0076] The present disclosure provides a fuel pre-heating system of vehicle to
decrease fuel consumption of engine.

We Claim:

1.A fuel pre-heating system for a vehicle, said system comprising:
a silencer unit coupled to an engine of the vehicle receives exhaust gases from the engine;
a fuel pipe, made of thermally conductive material, to carry fuel from a fuel tank to the engine, wherein the fuel pipe is looped through the silencer unit such that the exhaust gases flow around the fuel pipe to heat the fuel flowing in the fuel pipe to increase temperature of the flowing fuel; and
a device positioned proximal to the engine, the device comprising:
an upper disc coupled to a plunger of a fuel pump on an outer side of the upper disc; and
a lower disc rotary fitted with the upper disc, and coupled to a timing gear on its outer side, wherein the timing gear is configured to rotate the lower disc relative to the upper disc to control operation of the feed pump for optimum fuel flow from the fuel pump to increasing fuel efficiency of the engine.
2. The system as claimed in claim 1, wherein a bifurcater is positioned inside the silencer unit to enable bifurcation of the exhaust gases along the fuel pipe for increasing heat transfer to the fuel pipe from the exhaust gases.
3. The system as claimed in claim 1, wherein the upper disc is inscribed with a pointer, and wherein the loser disc is inscribed with angular marks to facilitate determination of angular rotation of the upper disc and the lower disc with respect to each other.
4. The system as claimed in claim 1, wherein the thermally conductive material is selected
from a group comprising of a copper and aluminium.
5. The system as claimed in claim 1, wherein external surface of the silencer unit is lined with thermally insulating material to prevent loss of heat to the environment.
6. The system as claimed in claim 1, wherein joints of the fuel pipe are configured as a part of the silencer unit.

7. The system as claimed in claim 1, wherein a heatproof gasket is used to join the silencer unit and exhaust of the engine.