Note: Descriptions are shown in the official language in which they were submitted.
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GENERATION OF ENERGY WITH FLUID
This invention relates to the generation of energy. More particularly, this
invention relates to a method of generating energy and to an apparatus for
generating energy.
It is well known to use a flow of fluid to generate energy in the form of
electricity
via suitable turbines and electrical generators. Examples of such arrangements
are the many and extensive hydroelectric systems presently in use. Such
systems use a head of water created through the construction of a dam to
create a flow of water through conduits in which turbines are positioned.
While
such systems can be referred to as "clean", the construction of the dams can
negatively impact the environment.
Other examples of sources of "clean" energy are wind farms and the like which
generate electricity by harnessing the energy of wind.
The environmental problems associated with fossil fuels are well known. A
large number of environmentally friendly proposals for the generation of
energy
have been considered and researched.
For example, the sea has been studied in depth as a source of energy.
Systems which use wave motion to generate energy have been well researched
and a number of prototypes have been built.
As is known, velocity is a major factor in the calculation of energy. The
energy
of a moving object is governed by the equation:- E =1 / 2(mv2 ) where
E = Energy;
i
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2
m = mass of the object; and
v = velocity of the object
It follows that a percentage increase in the velocity has a much greater
effect
than a similar percentage increase in mass. The result of the above equation
is
that a slow moving body of fluid requires a large and costly prime mover to
generate the necessary motion. Thus, while the body of fluid may well be
capable of providing substantial energy, it is the harnessing of that energy
which is difficult and time consuming.
In order to generate an adequate supply of electricity to render a system
profitable, a velocity of fluid flow should be high enough to avoid the
necessity
of providing costly and complicated prime movers. It is essential that a
system
be commercially self-sustaining in order to attract the necessary capital
1 s investment. It is a problem with presently known systems that their cost
is too
high to justify industrial implementation. Further, with the various systems
which are presently used, it is well known that it is difficult to obtain a
sufficiently
high fluid velocity. As a result, fossil fuels continue to be relied on for
the
generation of electricity.
It is therefore desirable that a means is provided whereby these disadvantages
are overcome or alleviated without incurring excessive costs.
Thus, according to a first aspect of the invention, there is provided a method
of
2s generating energy, the method including the steps of:
positioning a conduit means in a naturally occurring flow of fluid so that
an inlet of the conduit means is upstream of an outlet of the conduit means,
said conduit means being symmetrical about a longitudinal axis and having two
pairs of opposite walls comprising top and bottom walls and opposite side
walls,
3o said walls extending continuously between said inlet and said outlet, at
least
one pair of said opposite walls being curved inwardly and symmetrically
towards each other between said inlet and outlet to define a constriction
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3
between said inlet and the outlet so that the velocity of flow of the fluid is
increased through the constriction; and
driving an energy take-off means with a suitable prime mover positioned
in the constriction defined in the conduit means, the prime mover being
s configured to move in response to the flow of fluid through the
constriction.
The conduit means may be supported on a suitable support means positioned
in the flow of fluid. Instead, the conduit means may be suspended from a
suitable structure.
According to a second aspect of the invention, there is provided a method of
generating energy, the method including the steps of:
providing a passage between two bodies of naturally occurring
fluid, the passage having an inlet and an outlet and being defined by two
pairs
of opposite side walls extending continuously between said inlet and outlet,
the
walls of at least one pair of said side walls being curved inwardly and
symmetrically towards each other to define a constriction intermediate said
inlet
and said outlet, the bodies of fluid defining a pressure gradient so that a
flow of
fluid is created through the passage with a velocity of flow increasing
through
2o the constriction; and
driving an energy take-off means with a suitable prime mover positioned
in the constriction, the prime mover being configured to move in response to
the flow of fluid through the constriction.
According to a third aspect of the invention, there is provided an apparatus
for
generating energy, the apparatus including;
a conduit means that defines an inlet and an outlet, said conduit
means having two pairs of opposite side walls extending continuously between
said inlet and said outlet, the walls of at least one said pair of side walls
3o converging symmetrically towards each other between said inlet and said
outlet
to define a constriction intermediate the inlet and outlet whereby velocity of
fluid
flow through the conduit means increases through the constriction; and
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a prime mover positioned in the constriction to drive an energy
take-off means, the prime mover being configured to move in response to the
flow of fluid through the constriction.
It will be appreciated that the velocity increase is governed by
A, v, = Azvz = A3V3, where
A, = cross sectional inlet area;
Az = cross sectional area at constriction;
A3 = cross sectional outlet area;
v, = velocity at inlet;
v2 = velocity at constriction; and
v3 = velocity at outlet.
By forming the constriction between walls which are continuous between inlet
~5 and outlet, flow through the conduit remains substantially laminar.
Turbulence
within the conduit upstream of the prime mover is undesirable. The geometrical
configuration of the conduit means is such that laminar flow through the
conduit
means is facilitated.
2o The conduit means may be in the form of an elongate, tubular member which,
at least along a portion of its length, defines a passage of continuously
decreasing cross sectional area to a constriction point intermediate the inlet
and the outlet and, thereafter, of continuously increasing cross sectional
area
away from said point.
The conduit means may have two pairs of opposed walls to define a
rectangular transverse profile. At least one pair of the opposed walls may
curve
towards each other to define the constriction. The at least one pair of walls
of
the passage suitably have a parabolic axial profile to define the
constriction.
The prime mover may be in the form of at least one set of blade members
mounted on a shaft. Each blade member may be positioned and configured so
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that the shaft is rotated when fluid passes through the passage. The
blade members of the, or each, set may be oriented to extend between one of
the pairs of opposed walls. The shaft and the blade members may be
positioned orthogonally with respect to a direction of flow through the
conduit
s means. Thus, an axis of rotation of the shaft and the blade members is
orthogonal with respect to the direction of flow.
Each blade member may be mounted on its respective shaft via one or more
arms that extend radially from the shaft.
io
Each blade member may be adjustably mounted on its respective arms so that
the blade members can be adjusted to produce maximum response to the flow
of fluid through the conduit means.
is The blade members and the, or each, shaft may be substantially vertically
oriented when the conduit means is in an operative position. Instead, the
blade
members and the, or each, shaft may be substantially horizontally oriented
when the conduit means is in an operative position.
2o The apparatus may include an energy take-off means that is connected to
the,
or each, shaft. The, or each, energy take-off means may include an electrical
generator for generating electricity.
A plurality of sets of blade members and corresponding generators may be
2s mounted on the conduit means.
According to a fourth aspect of the invention, there is provided a conduit for
a
moving fluid used in the generation of energy, the conduit having an inlet and
an outlet and a constriction intermediate the inlet and the outlet, said
conduit
3o being symmetrical about a longitudinal axis and having two pairs of
opposite
side walls extending continuously between said inlet and outlet, the walls of
one
said pair of walls converging symmetrically towards each other between said
inlet and said outlet so that the cross-sectional area of the conduit
decreases
gradually and substantially continuously from the inlet of the passage to said
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6
constriction and increases gradually and substantially continuously from
said constriction to said outlet whereby the velocity of flow of fluid is
increased
through said constriction.
s The side walls of the one pair of side walls suitably comprise curve
inwardly
towards and the walls of the other pair of side walls are suitably
substantially
planar. Suitably, the curved walls define a parabolic curve. Preferably,
panels
are mounted or arranged adjacent the one pair of side walls to define a
structure having planar sides
to
Generation of energy in accordance with this invention may manifest itself in
a
variety of forms. It will be convenient hereinafter to describe in detail some
preferred embodiments of the invention with reference to the accompanying
drawings. The purpose of this specific description is to instruct persons
having
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7
an interest in the subject matter of the invention how to carry the invention
into
practical effect. It is to be clearly understood however that the specific
nature of
this description does not supersede the generality of the preceding broad
description. In the drawings:
FIG 1 shows, schematically, a three dimensional view of one
embodiment of an apparatus, in accordance with the invention, for
generating energy;
FIG 2 shows, schematically, - a sectioned plan view taken through a
generator housing of the apparatus of FIG 1;
FIG 3 shows, schematically, a turbine of an apparatus, in accordance
with the invention, for generating electricity;
FIG 4 shows an alternative manner of supporting the apparatus of FIG 1
in a flow of fluid;
FIG 5 shows one possible embodiment of an apparatus, in accordance
the invention, for generating energy;
FIG 6 shows, schematically, a plan view of a prime mover of an
apparatus, in accordance with the invention, for generating energy;
FIG 7 shows, schematically, a three dimensional view of part of a blade
member and its associated arm of an apparatus, in accordance with the
invention, for generating energy;
FIG 8 shows, schematically, a cutaway view of an embodiment of an
apparatus, in accordance with the invention, for generating energy;
FIG 9 shows, schematically, a three dimensional view of the apparatus of
FIG 8;
FIG 10 shows, schematically, three possible conduit shapes for an
apparatus, in accordance with the invention, for generating energy;
FIG 11 shows, schematically, a three dimensional view of a possible
embodiment of a conduit, in accordance with the invention, for a moving
fluid used in the generation of energy;
FIG 12 shows, schematically, a typical installation of an apparatus, in
accordance with the invention, for generating energy; and
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FIG 13 shows, schematically, another typical installation of an apparatus, in
accordance with the invention, for generating energy.
The various embodiments of the apparatus described below are intended
s primarily for the generation of electricity however the invention may be
extended to any form of energy generation.
Referring firstly to FIGS 1 and 2, the apparatus 10 for generating energy
includes a conduit means in the form of a conduit 12 which includes a pair of
~o opposed side walls 14, a lower wall 16 and an upper wall 18. The walls 14,
16,
18 define a passage 20 having an inlet 22 and an outlet 24. The lower and
upper walls 16 and 18 are planar.
The conduit 12 is symmetrical about a longitudinal axis with the side walls 14
15 being continuous between the inlet 22 and outlet 24 and curving inwardly
and
symmetrically towards each other to define a constriction 26 at the area of
minimum cross section of the conduit 12 which is arranged centrally between
the inlet 22 and the outlet 24. The walls 14 are thus internally convex. Edges
17 of the upper and lower planar walls 18 and 16 are shaped to correspond
2o with the curvature of each side wall 14. The curve of each side wall 14 is
preferably parabolic.
It will be appreciated that, between the inlet 22 and the outlet 24, the cross
sectional area of the passage 20 decreases gradually and continuously until a
2s certain point in the constriction 26 ;s reached. Thereafter, the cross
sectional
area increases gradually and continuously. Thus, a relatively smooth
transition
occurs between the inlet 22, the constriction 26 and the outlet 24. Further
the
inlet 22 and outlet 24 have substantially the same cross section such that the
conduit 12 is also symmetric about a plane extending normal to the
longitudinal
so axis of the conduit at the constriction 26 as is also apparent in Figs. 2
and 10.
In use, the conduit 12 is located in a naturally occurring flow of water 28
such
that the inlet 22 is positioned upstream of the outlet 30.
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Those with an understanding of fluid flow will appreciate that a velocity of
the
water increases at the constriction 26. This is as a result of the simple
equation
Q - Alv1 = A2v2 - A3V3
where
Q= flow rate through the conduit 12
A, = cross sectional area of the inlet 22
Az = cross sectional area at the constriction 26;
A3 = cross sectional area of the outlet 24;
v, = velocity at the inlet 22;
vz = velocity at the constriction 26; and
v3 = velocity at the outlet 24.
Since A, and A3 are both larger than AZ , v2 is proportionately larger than v,
and
v3 '
The invention makes use of this characteristic by positioning a prime mover
(described later) in or near the constriction 26. The prime mover is
configured
to be acted upon by the water passing through the conduit 12 to rotate at a
speed proportional to the velocity of the water in the conduit 12.
The prime mover is positioned at a point where the velocity of the water in
the
conduit 12 is at a maximum. it is a rule of physics that velocity is the most
significant factor effecting the energy output of a system. This can be
exploited
by positioning the prime mover in the constriction 26.
In order to utilise the energy generated by the rotating prime mover, an
electricity generating arrangement 30 is mounted on the upper wall 18 of the
conduit 12. The arrangement 30 includes a generator housing 32 which is
mounted on the upper wall 18 and houses a generator, indicated schematically
at 34..
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The generator 34 can be in the form of any suitable electricity generator and
is
tailored to suit the application of the apparatus 10. As can be seen in FIG 2,
a
simple gear arrangement, shown schematically at 36, can be used to connect
5 the prime mover to the generator 34.
In FIG 3, a turbine 38 is shown schematically. The turbine 38 includes a prime
mover 40. The prime mover 40 has a shaft 42 and three blade members or
blades 44. Each blade 44 is spaced from, and is parallel to, the shaft 42. The
10 shaft 42 extends through the upper wall 18 with a lower end 47 to be
mounted
on a bearing 46 on the lower wall 16. A power take off end 48 of the shaft 42
has a gear 50 of the arrangement 36 fixed thereto. The gear 50 is geared to
the
generator 34.
Each blade 44 is mounted to the shaft 42 via a pair of spaced arms 52.
The prime mover 40 includes three blades 44.
The relative orientation of the blades 44 and the shaft 42 is shown in FIG 6.
Each blade 44 has a wing-like transverse profile. Furthermore, each blade 44
is
oriented with respect to its respective arms 52 so that, when water flows in
the
direction of an arrow 54 the water acts on the blades 44 to cause rotation of
the
shaft 42 in the direction of an arrow 56. This rotation is used to drive the
generator 34.
As can be seen in FIG 7, the blades 44 are adjustably mounted on their
respective arms 52. This is facilitated via an adjustment mechanism indicated
at
53. This permits the blades 44 to be adjusted as shown by the arrow 55 so that
a maximum speed of rotation relative to the velocity of the flow can be
obtained.
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One way of mounting the apparatus 10 in the water is shown in FIG 1. In this
example, the conduit 12 is mounted on concrete stands 58 fixed in a bed 60
over which the water flows.
In FIG 4, there is shown another way in which the conduit 12 is supported. As
can be seen in FIG 4, the conduit 12 can be suspended from piles 62 driven
into the bed 60.
It will readily be appreciated that any number of turbines 38 can be mounted
in
the conduit 12.
A particular example is shown in FIG 5 where a second turbine 66 is provided.
The second turbine 66 is connected to an air compressor 64. The air
compressor 64 serves to provide a supply of compressed air which can be used
to drive the generator 34 during periods of reduced flow through the conduit
12.
In the above examples, the shaft 42 has been shown in a vertical orientation.
It
will be appreciated that the shaft or shafts 42 can just as easily be mounted
horizontally, depending on location and constructional requirements. An
example of the shafts 42 being horizontally mounted is shown in FIGS 8 and 9.
When the shafts 42 are in the horizontal position, the generator housing 32
and
generator 34 are simply mounted on one of the side walls 14.
The conduit 12 can be provided with different proportions. Three possible
shapes are shown in FIG 10. The shape chosen for the conduit 12 depends on
the proposed location for the conduit 12 and the conditions of water flow in
that
location. It will be appreciated that, by enlarging the inlet 22, the amount
of
water directed into the conduit 12 is increased. This can be useful in areas
where the flow rate is high but the natural velocity is low.
As can be seen in FIG 11, further panels 68, shown with diagonal lines for the
purposes of clarity, can be mounted on the walls 14, 16, 18 so that the
conduit
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12 has four substantially planar sides 70. It will be appreciated that a space
will
then be defined adjacent each opposed side wall 14. This space can be used
to house the electricity generating arrangement 30.
In FIG 12, there is shown a possible application of an apparatus, in
accordance
with the invention, for generating energy. As can be seen, the conduit 12 is
positioned to traverse a region 72 having a body of water 74 on one side of
the
region 72 and a body of water 78 on another side 80 of the region 72. The
bodies of water 74, 78 are such that a pressure gradient exists between such
bodies. As a result of this pressure gradient, a flow of water is set up
between
the region 72 and a further region 82 of land. By positioning the conduit 12
as
shown in FIG 12, use is made of this pressure gradient to provide a flow of
water through the conduit 12. A plurality of the turbines 38 are positioned in
the
constriction 26. A generator house 84 is positioned on the conduit 12 to house
generators 34 associated with respective turbines 38.
The conduit 12 is positioned in an underground channel indicated schematically
at 86 which extends from the one side 76 to the other side 80.
It will be appreciated that the dimensions of the conduit 12 will depend upon
the
size of the region 72 chosen for installation of the apparatus of this
invention.
In FIG 13, there is shown two apparatus, both in accordance with the
invention,
for generating energy, positioned in a naturally occurring flow of water,
indicated
schematically at 88. This flow of water 88 is generated as a result of a
substantial pressure gradient existing between two bodies of water 90 in fluid
communication with each other via a naturally occurring channel 92. Each of
the apparatus 10 is positioned in the channel 92 and is oriented to make use
of
the flow existing through the channel 92.
The applicant believes that this invention provides a means whereby
electricity
can be generated using naturally existing bodies of water which define a
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pressure gradient or naturally occurring flows of fluid. Furthermore, it is
submitted that this invention provides a means whereby electricity can be
generated in a way that is profitable and self-sustaining.
In the non-limiting examples given above, the fluid in question is in the form
of
water. Where a region is encountered which separates two bodies of water that
define a pressure gradient, the applicant can, by means of this invention,
simply
set up a flow of water which can then be utilised to generate electricity.
tnstead,
the apparatus of this invention can simply be used where a naturally occurring
flow of water already exists.
The relatively large inlet area serves to guide a sufficiently large body of
water
towards the constriction 26. The increased velocity of this body of water is
what
provides this invention with the ability to generate electricity in a cost
effective
and useful manner.
The increased velocity at the constriction 26 obviates the need for large and
expensive prime movers. Instead, a smaller, simpler and more cost effective
prime movers can be used to generate electricity than that which would be
required with the prior art.
It will of course be realised that the above has been given only by way of
illustrative example of the invention and that all such modifications and
variations thereto as would be apparent to persons skilled in the art are
deemed
to fall within the broad scope and ambit of the invention as is herein set
forth.
