GENERATION OF ENERGY WITH FLUID

Abstract: An apparatus for generating energy includes a conduit means (12) that defines an inlet (22), an outlet (24) and constriction (26). At least one turbine (38) is mounted on the conduit means (12) in or near the constriction (26). Each turbine (38) has a set of blade members mounted on a shaft. Each blade member is connected to the shaft and extends into the conduit means (12) on a line parallel to the shaft. The blade members are configured and oriented with respect to each other so that the blade members co-operate to produce rotation of the shaft when a fluid flows through the conduit means (12).

Description: 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 = l/2(mv 2 ) where E = Energy; 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 investment. It is a problem with presently known systems that their cost is too high to justify industrial implementation. As a result, fossil fuels continue to be relied on for the generation of electricity. This is clear with the various systems which are presently used and it is well known that it is difficult to obtain a sufficiently high fluid velocity with such systems. It is therefore desirable that a means be provided whereby these disadvantages are overcome without incurring excessive costs. Thus, according to a first aspect of the invention, there is provided a method of generating energy, the method including the steps of: positioning a conduit means in a naturally occurring fluid stream so that an inlet of the conduit means is upstream of an outlet of the conduit means, a constriction being defined between the inlet and the outlet so that a 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 configured to move in response to the flow of fluid through the constriction. The method may include positioning the conduit means in a naturally occurring flow of fluid. 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 defining an inlet, an outlet and a constriction intermediate the inlet and the 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 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. The method may include providing the passage by positioning a conduit means between the two bodies of naturally occurring fluid, the conduit means defining the inlet, the outlet and the constriction intermediate the inlet and the outlet The method may include forming a passage between the two bodies of fluid and positioning the conduit means in the passage. 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, an outlet, and a constriction intermediate the inlet and the outlet, the conduit means being shaped so that a velocity of flow through the conduit increases through the constriction; and 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 t ; = A 2 v 2 = A 3 v 3 , where A x = cross sectional inlet area; A 2 = cross sectional area at constriction; A 3 = cross sectional outlet area; v, = velocity at inlet; v 2 = velocity at constriction; and v 3 = velocity at outlet. It will further be appreciated that the constriction should be continuous so that 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 may therefore be such that laminar flow through the conduit means is facilitated. 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 point intermediate the inlet and the outlet and, thereafter, of continuously increasing cross sectional area away from said point. At least a portion of the tubular member may be waisted to define the constriction. The constriction may have a parabolic axial profile. 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 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 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 means. Thus, an axis of rotation of the shaft and the blade members may be 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. Each blade member may be adjustably mounted on its respective arm/s so that the blade members can be adjusted to produce maximum response to the flow of fluid through the conduit means. 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. 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 prime movers and corresponding generators may be mounted on the conduit means. According to a fourth 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; and at least one turbine mounted on the conduit means, each turbine having a set of blade members mounted on a shaft, each blade member being connected to the shaft and extending into the conduit means on a line substantially parallel to the drive shaft, the blade members being configured and oriented with respect to each other so that the blade members cooperate to produce rotation of the shaft when a fluid flows through the conduit means. According to a fifth aspect of the invention, there is provided a conduit for a moving fluid used in the generation of energy, the conduit including a passage-defining member that defines a passage having an inlet and an outlet, the passage-defining member being shaped to define a constriction in the passage intermediate the inlet and the outlet of the passage. The passage-defining member may be shaped so that a cross-sectional area of the passage decreases gradually and substantially continuously from the inlet of the passage to a point intermediate the inlet and the outlet of the passage. The passage may increases gradually and substantially continuously from said point to the outlet of the passage so that a constriction is defined intermediate the inlet and the outlet. 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 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 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 primarily for the generation of electricity. It will, however, be appreciated that the invention extends to any form of energy generation and the use of electricity in the following examples should not be construed as limiting the scope of the invention. In the above drawings, and particularly with reference to FIGS 1 and 2, reference 10 generally indicates a first embodiment of an apparatus, in accordance with the invention, for generating energy. The apparatus 10 includes a conduit means in the form of a conduit 12. The conduit 12 includes a pair of 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 side walls 14 curve inwardly towards each other to define a constriction 26 intermediate the inlet 22 and the outlet 24. Edges 17 of the upper and lower walls 18, 16 are shaped to correspond with the curvature of each side wall 14. The curve of each side wall 14 is parabolic. It will be appreciated that, between the inlet 22 and the outlet 24, a cross sectional area of the passage 20 decreases gradually and continuously until a certain point in the constriction 26 is 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. in use, the conduit 12 is positioned in a naturally occurring flow of water 28. The conduit 12 is positioned so that the inlet 22 is upstream of the outlet 30. 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 = A v λ = A 2 v 2 = A 3 v 3 where Q= flow rate through the conduit 12 ' 4 = cross sectional area of the inlet 22 A 2 = cross sectional area at the constriction 26; -4 3 = cross sectional area of the outlet 24; v, = velocity at the inlet 22; v 2 = velocity at the constriction 26; and v 3 = velocity at the outlet 24. Since A and A 3 are both larger than A 2 , v 2 is proportionately larger than v, and 3 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. 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 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 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. 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 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 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. Instead, 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 mover/s 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.

Claims: CLAIMS: 1. A method of generating energy, the method including the steps of: positioning a conduit means in a naturally occurring fluid stream so that an inlet of the conduit means is upstream of an outlet of the conduit means, a constriction being defined between the inlet and the outlet so that a 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 configured to move in response to the flow of fluid through the constriction. 2. A method according to claim 1 , which includes positioning the conduit means in a naturally occurring flow of fluid. 3. A method according to claim 2, which includes supporting the conduit means on a suitable support means positioned in the flow of fluid. 4. A method according to claim 2, which includes suspending the conduit means from a suitable structure. 5. A method of generating energy, the method including the steps of: providing a passage between two bodies of naturally occurring fluid, the passage defining an inlet, an outlet and a constriction intermediate the inlet and the 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 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. 6. A method according to claim 5, which includes the step of providing the passage by positioning a conduit means between the two bodies of naturally occurring fluid, the conduit means defining the inlet, the outlet and the constriction intermediate the inlet and the outlet. 7. A method according to claim 6, which includes forming a passage between the two bodies of fluid and positioning the conduit means in the passage. 8. A method of providing a source of energy, the method including the steps of forming a passage between two bodies of naturally occurring fluid, the bodies of fluid defining a pressure gradient so that a flow of fluid is created through the passage. 9. A method according to claim 8, which includes positioning at least one prime mover in the passageway to drive an energy take-off means. 10. A method according to claim 8 or claim 9, which includes positioning a conduit means in the passageway, the conduit means having an inlet and an outlet, with a constriction being defined between the inlet and the outlet so that a velocity of flow of the fluid is increased through the constriction. 11. An apparatus for generating energy, the apparatus including: a conduit means that defines an inlet, an outlet, and a constriction intermediate the inlet and the outlet, the conduit means being shaped so that a velocity of flow through the conduit increases through the constriction; and 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. 12. An apparatus according to claim 11 , in which the conduit means is 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 point intermediate the inlet and the outlet and, thereafter, of increasing cross sectional area away from said point. 13. An apparatus according to claim 11 or claim 12, in which at least a portion of the tubular member is waisted to define the constriction. 14. An apparatus according to any one of claims 11 to 13, in which the constriction has a parabolic axial profile. 15. An apparatus according to any one of claims 11 to 14, in which the conduit means has two pairs of opposed walls to define a rectangular transverse profile. 16. An apparatus according to claim 15, in which at least one pair of the opposed walls curve towards each other to define the constriction. 17. An apparatus according to claim 15 or claim 16, in which the prime mover is in the form of at least one set of blade members mounted on a shaft, each blade member being configured and positioned so that the shaft is rotated when fluid passes through the passage. 18. An apparatus according to claim 17, in which the blade members of the, or each, set are oriented to extend between one of the pairs of opposed walls, with the shaft and the blade members being positioned orthogonally with respect to a direction of flow through the conduit means so that an axis of rotation of the shaft and the blade members is orthogonal with respect to the direction of flow. 19. An apparatus according to claim 18, in which each blade member is mounted on its respective shaft via one or more arms that extend radially from the shaft. 20. An apparatus according to claim 19, in which each blade member is adjustably mounted on its respective arm/s so that the blade members can be adjusted to produce maximum response to the flow of fluid through the conduit means. 21. An apparatus according to any one of claims 17 to 20, in which the blade members and the, or each, shaft are substantially vertically oriented when the conduit means is in an operative position. 22. An apparatus according to any one of claims 17 to 20, in which the blade members and the, or each, shaft are substantially horizontally oriented when the conduit means is in an operative position. 23. An apparatus according to any one of claims 17 to 22, which includes an energy take-off means that is connected to the, or each, shaft. 24. An apparatus according to claim 23, in which the, or each, energy takeoff means includes an electrical generator for generating electricity. 25. An apparatus according to any one of claims 17 to 24, in which a plurality of prime movers and corresponding generators are mounted on the conduit means. 26. An apparatus for generating energy, the apparatus including a conduit means that defines an inlet and an outlet; and at least one turbine mounted on the conduit means, each turbine having a set of blade members mounted on a shaft, each blade member being connected to -the shaft and extending into the conduit means on a line substantially parallel to the shaft, the blade members being configured and oriented with respect to each other so that the blade members cooperate to produce rotation of the shaft when a fluid flows through the conduit means. 27. An apparatus according to claim 26, in which the conduit means defines a constriction intermediate the inlet and the outlet, the conduit means being shaped so that a velocity of flow through the conduit increases through the constriction. 28. A prime mover for harnessing energy from a flow of fluid, the prime mover including a shaft that is rotatably mountable on a substructure; and a number of elongate blade members that are mounted to the shaft and are spaced from, and substantially parallel to, the shaft, the blade members being configured and oriented so that a flow of fluid substantially orthogonal to the shaft acts on the blade members to cause rotation of the shaft. 29. A prime mover according to claim 28, in which each blade member is mounted to the shaft via one or more radially extending arms. 30. A prime mover according to claim 29, in which each blade member is adjustably mounted on its respective arm/s. 31. A conduit for a moving fluid used in the generation of energy, the conduit including 31. A conduit for a moving fluid used in the generation of energy, the conduit including a passage-defining member that defines a passage having an inlet and an outlet and a constriction intermediate the inlet and the outlet, the passage-defining member being shaped so that a velocity of a flow of fluid is increased through the constriction. 32. A conduit according to claim 31 , in which the passage-defining member is shaped so that a cross sectional area of the passage decreases gradually and substantially continuously from the inlet of the passage to a point intermediate the inlet and the outlet of the passage and increases gradually and substantially continuously from said point to the outlet of the passage. 33. A conduit according to claim 32, in which the passage-defining member has two pairs of opposed walls, one pair of the walls being curved inwardly towards each other to define the constriction, with the remaining two pairs having edges corresponding to the curvature of said pair of opposed walls. 34. A conduit according to claim 33, in which each of the curved walls defines a parabolic curve. 35. A conduit according to claim 33 or claim 34, in which further panels are mounted on the passage-defining member to define a structure having planar sides. 36. A new method of generating energy, substantially as described herein. 37. A new apparatus for generating energy, substantially as described herein, with reference to the accompanying drawings. 38. A new prime mover for harnessing energy from a flow of fluid, substantially as described herein, with reference to the accompanying drawings. 39. A new conduit for a moving fluid used in the generation of energy, substantially as described herein, with reference to the accompanying drawings.

Inventors: DAVIDSON AARON, HILL CRAIG COLIN, DAVIDSON, AARON, HILL, CRAIG, COLIN
Applicants: DAVIDSON AARON, HILL CRAIG COLIN, DAVIDSON, AARON, HILL, CRAIG, COLIN
Application year: 1999
Main classification: F03B7
IPC codes: F03B7, F03B17, F03D3