WO2011005215A1

WO2011005215A1 - Hydroelectric inflow dam system

Info

Publication number: WO2011005215A1
Application number: PCT/SG2009/000247
Authority: WO
Inventors: Teng Choy Lam
Original assignee: Ip Management (Pte.) Ltd.
Priority date: 2009-07-10
Filing date: 2009-07-10
Publication date: 2011-01-13

Abstract

The present invention describes an inflow dam (30,130) for a hydroelectric system (10, 10a, 100,200). Water flowing into the inflow dam (30,130) is operable to turn a turbine (50, 50a, 150) and generator (60). A sleeve (36) with apertures (37) surrounding an inflow dam (50,50a) is operable to rotate or slide to align the apertures (37) with corresponding nozzles (40) on the inflow dam for regulating water flow. In another embodiment, a sleeve (136) is operable to slide on the inflow dam to regulate water head and flow over the top of the inflow dam (130).

Description

Hydroelectric Inflow Dam System

Field of Invention

[0001] The present invention relates to a hydroelectric dam system. In particular, the invention relates to hydroelectric power generating system by channeling hydraulic inflow from a body of water into a hollow channel.

Background

[0002] Renewable "green" power technologies are increasingly being sought as they are the key to creating a clean and green energy for the future. These renewable energy sources such as solar, wind and water are also natural resources. Water or hydro power is the largest source of clean and green electricity; it accounts for about 20% of all electricity produced globally and the technology involved is proven.

[0003] These hydroelectric plants are usual huge and involve a lot of investments. There is therefore a need to extract the potential energy of a smaller body of stored or running water to generate a clean source of electricity.

Summary

[0004] The following presents a simplified summary to provide a basic understanding of the present invention. This summary is not an extensive overview of the invention, and is not intended to identify key features of the invention. Rather, it is to present some of the inventive concepts of this invention in a generalised form as a prelude to the detailed description that is to follow.

[0005] The present invention seeks to provide a system for exploiting the potential energy of a body of water to generate electricity. In another embodiment, the present invention provides a hydroelectric system. The system comprises: a body of water; an inflow dam built in the body of water, with said inflow dam having an internal cavity; a turbine disposed inside the inflow dam; a generator connectable to the turbine; and a discharge channel for water flow downstream of the turbine.

[0006] In an embodiment of the hydroelectric system, the inflow dam is higher than the highest water level and water flows into the internal cavity of the inflow dam through nozzles so that kinetic energy of the water jets shaped by the nozzles is imparted to rotate the turbine and generator to generate electricity. In one embodiment, the inflow dam is submerged in the body of water. In another embodiment, the nozzles form one or more rows of nozzles disposed on the circumference of the inflow dam and the number of rows of nozzles correspond with the number of turbines or impellers of the turbine. In yet another embodiment, impellers of the turbine are elongate and are substantially parallel or spiral to the axis of rotation of the turbine; one or more water jets shaped by the nozzles are operable to impinge on an elongate impeller.

[0007] In another embodiment of the hydroelectric system, the inflow dam is lower than a low water level so that water flows into the internal cavity of the inflow dam and the dynamic pressure and flow of water are operable to rotate the turbine and generator to generate electricity.

[0008] In one embodiment of the hydroelectric system, an external surface of the inflow dam is surrounded by a sleeve, with said sleeve having apertures that correspond to the nozzles to control water flow through the nozzles. In one embodiment, the sleeve is rotatable about the inflow dam; in another embodiment, the sleeve is axially slidable on the inflow dam.

[0009] In another embodiment of the hydroelectric system, the top of the inflow dam is closed by a detachable cover and a valve plate disposed on the cover.

Brief Description of the Drawings

[0010] This invention will be described by way of non-limiting embodiments of the present invention, with reference to the accompanying drawings, in which: [0011] FIG. IA illustrates a cross-section of an in-flow dam for use with a turbine according to an embodiment of the present invention;

[0012] FIG. IB illustrates an inflow dam with two rows of nozzles for use with a turbine having two rows of impellers according to another embodiment of the present invention;

[0013] FIGs. 1C and ID illustrate a cross-section of an inflow dam for use with a turbine having elongate impellers;

[0014] FIG. 2 illustrates a cross-section of an inflow dam for use with a turbine according to another embodiment of the present invention; and

[0015] FIG. 3 illustrates a system of inflow dams according to yet another embodiment of the present invention.

Detailed Description

[0016] One or more specific and alternative embodiments of the present invention will now be described with reference to the attached drawings. It shall be apparent to one skilled in the art, however, that this invention may be practised without such specific details. Some of the details may not be described at length so as not to obscure the invention. For ease of reference, common reference numerals or series of numerals will be used throughout the figures when referring to the same or similar features common to the figures.

[0017] FIG. IA shows a system 10 using a turbine 50 to generate hydro-electricity according to an embodiment of the present invention. As shown in FIG. 1, the system 10 is made up of a body of water 20, for example being stored behind an embankment 22. An inflow, dam 30 having an internal cavity 32 is built in the body of water 20. The inflow dam 30 is built higher than the highest water level but the walls of the inflow dam 30 are formed with nozzles 40 so that jets of water flow from outside the inflow dam 30 into the internal cavity 32 and the kinetic energy in the water jets is imparted to the impellers of the turbine 50 for rotating the turbine. The turbine 50 is connected to a generator 60 through a drive shaft 52 and, where necessary, a gear system 54. The water downstream of the turbine flows into a discharge channel 70 and then into a discharge pipe 80 before the water is discharged to a lower ground.

[0018] In a variation, as shown in FIG. IB, of the above embodiment, the nozzles 40 are disposed on two or more circumferential rows around the inflow dam 30. The number of rows of nozzles 40 correspond with the number of turbines 50.

[0019] FIG. 1C shows a system 10a to generate hydro-electricity according to another embodiment of the present invention. The system 10a is similar to that of system 10 and the same series of reference numerals are used for similar elements; for example, 40a,40b etc refer to the nozzles, and 50a refers the turbine. As shown in FIG. 1C, the impellers of the turbine 50a are elongate and substantially parallel or spiral about the axis of rotation of the turbine, and two or more jets of water are operable to impart kinetic energy to each impeller of the turbine 50a. In a variation, as shown in FIG. ID, the nozzles 40a are also elongate and they generate water jets with elongate cross- sectional area to impart kinetic energy to each elongate impeller of the turbine 50a.

[0020] In one embodiment, the inflow dam 30 shown in FIGs. IA- ID is circular in its external dimension. As shown in FIG. IA, the inflow dam 30 has a shoulder 34 around the inflow dam and a rotatable sleeve 36 supported on the shoulder 34. The shoulder 34 is located below the nozzle 40,40a and the sleeve 36 has a number of apertures 37 corresponding to the number of nozzles 40,40a so that the apertures 37 and nozzles 40,40a are in register. On the inflow dam 30 and surrounding each nozzle 40,40a is a seal 38. The sleeve 36 is rotatable, for example, by means of a fluid cylinder. When the apertures 37 are not in register with the nozzles 40,40a, water is prevented from flowing through the nozzles, for example, during maintenance of the hydro-electricity system 10,10a. In a variation, the inflow dam 30 does not have the shoulder but the upper end of the sleeve 36 has a flange 39 that is supported on the top edge of the inflow dam 30.

[0021] In another embodiment, the inflow dam 30 shown in FIGs. 1A-1D is non-circular in its external dimension. The external of the inflow dam 30 and the sleeve 36 may be square or polygonal. In this embodiment, the sleeve 36 is slidable on the external surface of the inflow dam 30, for example by means of a fluid cylinder 90, as shown in FIG. IB.

[0022] FIG. 2 shows a system 100 using a turbine 150 to generate hydro-electricity according to another embodiment of the present invention. As in the previous system 10, the system 100 also has a body of water 20, for example being stored behind an embankment 22. The system 100 includes an inflow dam 130 being built in the body of water, for example, below a low water level and the internal cavity 132 of the inflow dam is operable to be filled with water. Located inside a lower part of the cavity 132 is the turbine 150. The turbine 150 is connected to a generator 60 by a shaft 152, and where necessary, through a gear system 154. Preferably, the generator 60 is disposed above the highest water level. Due to gravity, water flows through the turbine 150; the dynamic pressure and hydraulic flow turn the impellers of the turbine 150. The mechanical energy of the turbine 150 is then converted to electricity in the generator 60. The discharge channel 70 after the turbine acts like a draft tube and it helps create suction at the discharge channel 70, thereby increasing the dynamic hydraulic flow and head across the turbine 150 and the electricity output from the generator 60.

[0023] As in the previous embodiments, a sleeve 136 is provided around the inflow dam 130. In one embodiment, the sleeve 136 is operable to extend above the top end of the inflow dam 130 so that water is prevented from entering the inflow dam 130, for example during maintenance. A seal 138 may be provided between the sleeve and the external surface of the inflow dam 130. In use, a fluid cylinder 90 may control the sleeve 136 for regulating the head and amount of water flow to the turbine 150.

[0024] FIG. 3 shows another hydro-electricity system 200 according to yet another embodiment of the present invention. The system 200 comprises of a network of the above systems 10, 10a, 100. The hydro-electric system 200 allows a user to select a number of the above systems 10,10a,100 to operate according to the electricity demand and available water head/hydraulic flow. This allows some of the inflow dams 30,130 to be closed, for example, for maintenance without disrupting the supply of electricity from the hydro-electric system 200. [0025] Known hydro-electric power plants are usually very large and they involve huge capital investments. They also tend to affect the local ecology once the dams associated with the hydro-electric plants are flooded. The present systems 10, 10a, 100, 200 provide another hydroelectric generating system that makes use an existing body of water; they may supply hundreds of kilowatt, if not megawatts, for example, to supplement an existing hydroelectric power plant. It is possible that the present systems 10,10a,100,200 are planned for a future body of water. The body of water may be part of a reservoir, a lake or a sea for storing water, flood control and/or irrigation.

[0026] While specific embodiments have been described and illustrated, it is understood that many changes, modifications, variations and combinations thereof could be made to the present invention without departing from the scope of the invention. For example, the body of water may be a lake, reservoir or a river. In another example, the inflow dam may be formed as a unit separate from the discharge pipe but are modularly connected, for example, by means of bolts and nuts. In yet another example, the inflow dams need not be open at the top; in FIGs. 1 A-ID, the inflow dams may be submerged, with the top of the inflow dams being closed, for example by a detachable cover, and water flows in through the nozzles at the side of the inflow dams; in FIG. 2, the inflow dams may similarly be submerged, with the top being closed by a detachable cover but has apertures for water flow into the inflow dam; a valve plate with apertures corresponding to those on the cover is rotatable to control water flow into the inflow dam. It is also possible that a hybrid turbine of those shown in FIGs. IA- ID and 2 be used and nozzles are accordingly provided on the sides and top of the inflow dams.

Claims

CLAIMS:

1. A hydroelectric system comprising:

a body of water;

an in-flow dam built in the body of water, with said inflow dam having an internal cavity;

a turbine disposed inside the inflow dam;

a generator connectable to the turbine; and

a discharge channel for water flow downstream of the turbine.

2. A hydroelectric system according to claim 1, wherein the inflow dam is higher than the highest water level and water flows into the internal cavity of the inflow dam through nozzles so that kinetic energy of the water jets shaped by the nozzles is imparted to rotate the turbine and generator to generate electricity.

3. A hydroelectric system according to claim 1, wherein the inflow dam is submerged in the body of water and water flows into the internal cavity of the inflow dam through nozzles so that kinetic energy of the water jets shaped by the nozzles is imparted to rotate the turbine and generator.

4. A hydroelectric system according to claim 2 or 3, wherein the nozzles form one or more rows of nozzles disposed on one or more circumferences of the inflow dam and the number of rows of nozzles correspond with the number of turbines.

5. A hydroelectric system according to claim 2 or 3, wherein impellers of the turbine are elongate and are substantially parallel or spiral to the axis of rotation of the turbine.

6. A hydroelectric system according to claim 5, wherein two or more rows of water jets impinge on each impeller of the turbine.

7. A hydroelectric system according to claim 5, wherein the nozzles are elongate in cross-sectional area and each jet of water is operable to impinge on each impeller of the turbine.

8. A hydroelectric system according to any one of the preceding claims, wherein an external surface of the inflow dam is surrounded by a sleeve, with said sleeve having apertures that correspond to the nozzles to control water flow through the nozzles.

9. A hydroelectric system according to claim 9, wherein a seal is disposed between the sleeve and the external surface of the inflow dam to stop water flow into the inflow dam when the apertures are not in register with the nozzles.

10. A hydroelectric system according to claim 8 or 9, wherein the external of the inflow dam is circular and the sleeve is rotatable about the inflow dam.

11. A hydroelectric system according to claim 8 or 9, wherein the external of the inflow dam is non-circular and the sleeve is axially slidable on the inflow dam.

12. A hydroelectric system according to claim 1, wherein the inflow dam is lower than a low water level so that water flows into the internal cavity of the inflow dam and the dynamic pressure and flow of water are operable to rotate the turbine and generator to generate electricity.

13. A hydroelectric system according to claim 12, wherein an external surface of the inflow dam is surrounded by a sleeve.

14. A hydroelectric system according to claim 13, wherein the sleeve is slidable on the inflow dam to control the flow rate of inflow water according to the water level.

15. A hydroelectric system according to claim 12, wherein a top of the inflow dam is closed by a cover but the cover is detachable and has apertures for water to flow into the inflow dam.

16. A hydroelectric system according to claim 15, wherein a valve plate is disposed on the cover for controlling water flow through apertures on the valve plate and those on the cover.

17. A hydroelectric system according to claim 16, wherein the valve plate is rotatable on the cover.

18. A hydroelectric system according to any one of the preceding claims, wherein the inflow dam and discharge pipe are formed separately but are connected for fluid communication.

19. A hydroelectric system comprising a network of the systems according to any one of claims 1-18.