US20090097961A1

US20090097961A1 - Hydroelectric System

Info

Publication number: US20090097961A1
Application number: US12/248,021
Authority: US
Inventors: Christopher George Edward Nightingale
Original assignee: Dragon Energy Pte Ltd
Current assignee: Dragon Energy Pte Ltd
Priority date: 2007-10-09
Filing date: 2008-10-08
Publication date: 2009-04-16
Also published as: EP2048303B1; EP2048303A1; GB0808487D0; DE602008000484D1; ATE453769T1; WO2009048432A3; CN101408147A; AU2008201979A1; GB2453612A; TW200928088A; SG152069A1; JP2009092070A; WO2009048432A2

Abstract

A hydroelectric system converts kinetic energy from water flowing off a roof of a building into electrical energy. The system comprises a turbine having a rotor and a generator disposed in a down pipe. The down pipe has an upper end that receives water running off the roof via gutters. The down pipe comprises first and second channels that extend from the upper end to respective outlets. Each of the outlets direct water onto the rotor causing rotation in the same direction. The channels are configured in a manner so that water entering the down pipe initially flows through the first channel and out from a first outlet. However in a heavy downpour the first channel may overflow into the second channel to subsequently flow out of a second outlet providing further drive to the rotor. A regulating reservoir is provided at the upper end of the down pipe to provide a controlled steady flow of water through the first channel. The reservoir has an upright wall provided with a lower outlet and an upper outlet. When water collects in the reservoir at a level below the outlet it flows into the first channel via the first outlet. If rain water volume within the reservoir increases sufficiently water will eventually flow through the second outlet into the first channel providing additional pressure to drive the turbine. Should the water level in the reservoir increase at a sufficiently greater rate than it flows out from the outlets it may then overflow the wall to flow down the second channel.

Description

CROSS-REFERENCE TO RELATED PATENT APPLICATION

This application claims the benefit of Singapore Patent Application No. 200716830-5, filed on Oct. 9, 2007, the disclosure of which is incorporated herein in its entirety by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention
The present invention relates to a hydroelectric system for converting kinetic energy from water flowing off a roof of a building to electrical energy.
2. Background
It has been previously proposed to incorporate a hydroelectric system to generate electricity from rain runoff from a roof. For example such a system is described in patent application no. DE 29711026 which discloses a rainwater powered electricity generation system having a storage tank that acts a reservoir to store rain water from a roof. When the level within the reservoir reaches a predetermined level, a valve automatically opens allowing the water to drain through a down pipe to drive a turbine which in turn drives a generator to produce electricity.
It is to be understood that, if any prior art publication is referred to herein, such reference does not constitute an admission that the publication forms a part of the common general knowledge in the art, in Australia or any other country.

SUMMARY OF THE INVENTION

According to the present invention there is provided a hydroelectric system for converting kinetic energy from water flowing off a roof of a building into electrical energy, the system comprising:
a turbine having a rotor;
at least one down pipe having an upper end for receiving the water, the down pipe further comprising at least two channels, each channel extending from the upper end to a respective outlet, each outlet disposed to direct water flowing therefrom on to the rotor to cause rotation of the rotor in the same direction, the channels being configured in a manner so that at least one channel can overflow into another channel.
Respective adjacent channels may be provided with corresponding upper edges of progressively increasing height whereby water overflowing the upper edge of one channel flows into an adjacent channel.
At least two of the channels may be provided with different hydraulic diameters. In one embodiment, the hydraulic diameter of a first of the channels into which water entering the down pipe initially flows is smaller than the hydraulic diameter of other channels.
In one embodiment, the rotor comprises an Archimedes screw having an axis of rotation parallel to a direction of flow of water from the channels.
The hydroelectric system may further comprise one or more gutters configured to receive water flowing from the roof and directing the water into the or each down pipe; and one or more roof channels, each roof channel disposed on the roof and extending from diagonally from an upper portion of the roof to the gutter.
The system may further comprise one or more water storage tanks in fluid communication with the or each down pipe for storing water that passes through the down pipe.
The down pipe may be further provided with a water flow regulating reservoir for at least one of the channels, the reservoir comprising an outlet in fluid communication with that channel, the outlet formed at a location below the upper edge of that channel and dimensioned to regulate flow of water collected in a reservoir down that channel. Each reservoir may be formed between a first wall of that channel, the first wall constituting the upper edge of that channel and a second wall spaced from the first wall, the second wall having an upper edge located below the upper edge of the first wall and wherein the outlet is formed in the second wall below the upper edge of the second wall.
These and other embodiments of the present invention are further made apparent, in the remainder of the present document, to those of ordinary skill in the art.

BRIEF DESCRIPTION OF THE DRAWINGS

An embodiment of the present invention will now be described by way of example only with reference to the accompanying drawings in which:

FIG. 1 is a schematic representation of an embodiment of the hydroelectric system in accordance with the present invention;

FIG. 2 is a top elevation view of a down pipe incorporated in the hydroelectric system; and,

FIG. 3 is a side elevation view of the hydroelectric system.

DETAILED DESCRIPTION OF THE SPECIFIC EMBODIMENTS

The accompanying drawings illustrate an embodiment of a hydroelectric system 10 in accordance with the present invention for converting kinetic energy from water flowing off a roof 12 of a building 14 into electrical energy. The system 10 comprises a turbine 16 having a rotor 18 and a generator 19 which is driven by the rotor 18, and at least one down pipe 20 having an upper end 22 for receiving the water run off from the roof 12. The down pipe 20 comprises channels 24 a and 24 b (hereinafter referred to in general as “channels 24”) that extend from the upper end 22 to respective outlets 26 a and 26 b (hereinafter referred to in general as “outlets 26”). Each of the outlets 26 is disposed to direct water flowing therefrom onto the rotor 18 to cause rotation of the rotor 18 in the same direction. As explained in greater detail below, the channels 24 are further configured in a manner so that the channel 24 a overflows into the channel 24 b.
Upper and lower fixing rings 21 a and 21 b hold the turbine 16 in place within the down pipe 22 as the rotor 18 rotates. One or both of the rings may also be used to rotate cables 50 between the generator 19 and an energy management system or storage device (neither shown).
The system 10 further comprises a gutter 28 that receives the water from the roof 12 and directs that water into the down pipe 20. The channels 24 a and 24 b are configured in a manner so that water entering the down pipe 20 initially flows through the channel 24 a and out from the outlet 26 a onto the rotor 18 to drive the generator 19. However in a heavy downpour the channel 24 a may overflow into the channel 24 b. The overflow water then flows through the channel 24 b through the outlet 26 b to turn the rotor 18 thereby providing further drive to the generator 19.
The overflow of water from channel 24 a to 24 b is facilitated by forming the channels 24 with respective upper edges of progressively increasing height whereby water overflowing the upper edge of one channel, for example channel 24 a, can subsequently flow into the adjacent channel 24 b. In this regard, it can be seen from FIG. 1 that the channel 24 a has an upper edge 30 a while the channel 24 b has an upper edge 30 b which is higher than the upper edge 30 a. Thus, if the channel 24 a fills with water and overflows, the overflow flows over the upper edge 30 a into the channel 24 b. It will be appreciated that if for example the down pipe 20 where provided with a further third channel, water would flow into the third channel after water has overflowed both the upper edge 30 a of the first channel 24 a and the upper edge 30 b of the second channel 24 b.
In order to provide a controlled steady flow of water through the channel 24 a, the upper end 22 of the down pipe 20 is provided with a water flow regulating reservoir 32. The reservoir 32 comprises an upright wall 36 that incorporates the upper edge 30 a of the channel 24 a, a base 37 that slopes downward, and a second upright wall 38 spaced from the wall 36.
The reservoir 32 is provided with two outlets to the channel 24 a. A first outlet 34 comprises a slot or series of holes formed in the wall 38 near its junction with the base 37. The second outlet, which is spaced above the first outlet, is simply a slot 40 formed near an upper end of the wall 38. The slot 40 in effect constitutes a spill way to the channel 24 a. Thus when water collects in the reservoir at a level below the slot 40 it flows into the channel 24 a via the first outlet 34. The outlet 34 is dimensioned to provided a steady continuous stream of water down the channel 24 a when a head of water is contained within the reservoir 32. If rainwater volume increases sufficiently water will initially flow through the slot 40 and flow into the channel 24 a providing additional pressure to drive the turbine 16. Should the water level in the reservoir 32 increase at a sufficiently greater rate than it flows out from the outlet 34 and through the slot 40 it may then overflow the edge 30 a to flow down the second channel 24 b.
The channels 24 may be provided with either the same or different hydraulic diameter. However, in a preferred embodiment the channel 24 a may have a smaller hydraulic diameter than the channel 24 b. The selection of the hydraulic diameter for the channel 24 a, the size of the opening 34, and the volume of the reservoir 32 may be selected to provide a constant flow of water through the channel 24 a.
Water flowing through the down pipe 20 and through the rotor 18 can flow via a tail portion 42 of the down pipe 20 into a water tank 44. The water tank 44 may be disposed either on the ground or underground. The tank 44 stores rainwater which can be used for various purposes including non potable uses such as watering of a garden, cleaning outdoor areas, washing machines and dishwashers, or alternately with the provision of appropriate filters, used for drinking water. Additionally, the water in the tanks 44 may be pumped through a solar heating system to provide either heated water for use within the building 14 such as for showers and washing machines, or alternately pumped through radiators for heating purposes. In such embodiments, pumping of the water from the tank 44 may ideally be powered by electricity generated by solar cells on the roof 12. The tank 44 may also be provided with an overflow valve 46 that is configured to open to allow excess water to drain from the tank 44 if the water pressure on the tank 44 is above a predetermined level that would be exceeded prior to the entirety of the down pipe 20 being filled with water.
FIG. 2 illustrates a particular configuration of a down pipe 20 where the channel 24 a comprises in effect a pipe within the down pipe. The gutter 28 feeds water directly to the mouth or opening of the channel 24 a which, when completely filled with water, can overflow into the channel 24 b which constitutes the region of the down pipe 20 between the outside of the channel 24 a and the inside of an outer pipe 46 defining the down pipe 20.
Referring to FIG. 3, it can further be seen that the hydroelectric system 10 may also include one or more roof channels 48 that extend diagonally from an upper portion of the roof 12 to the gutter 28. The roof channels 48 act to direct rain running of the roof 12 to flow in a direction at an acute angle to the direction of flow of water in the gutter 28. This provides added momentum or velocity to the water in the gutter 28 to thereby increase its kinetic energy. Depending on the state of the reservoir 32 and the size of the opening 34, the increase in kinetic energy provided to the water may provide greater electrical energy output from the turbine.
Electricity generated by the turbine 16 can be fed via the cable 50 to a power management system that may include a storage battery for storing the electricity. The management system may then manage the power generated by the turbine 16 to supply the power to appliances within the building 14 or even to deliver the power to a mains grid.
Now that an embodiment of the invention has been described in detail it will be apparent to those skilled in the relevant arts that numerous modifications and variations may be made without departing from the basic inventive concepts. For example, system 10 depicts a down pipe being divided into two channels 24 a and 24 b. However as previously mentioned, the down pipe 20 can be divided into more than two channels. Further, while it is believed that a rotor 18 in the form of an Archimedes screws may constitute a most efficient form of rotor, however the wheels or propellers may be used. Also the second outlet of the reservoir 32 which is described above, and shown, as a slot 40 can take alternate forms. For example the wall 38 can be simply made of a height equal to the bottom of the slot 40, so that the upper most edge of the wall 38 acts as a dam wall over which water flows. In a further variation the slot 40 can be replaced with a plurality of holes at the same height in the wall 38. All such modifications and variations are deemed to be within the scope of the present invention the nature of which is to be determined from the above description.
In the claims of this application and in the description of the invention, except where the context requires otherwise due to express language or necessary implication, the words “comprise” or variations such as “comprises” or “comprising” are used in an inclusive sense, i.e. to specify the presence of the stated features but not to preclude the presence or addition of further features in various embodiments of the invention.
Throughout the description and drawings, example embodiments are given with reference to specific configurations. It will be appreciated by those of ordinary skill in the art that the present invention can be embodied in other specific forms. Those of ordinary skill in the art would be able to practice such other embodiments without undue experimentation. The scope of the present invention, for the purpose of the present patent document, is not limited merely to the specific example embodiments or alternatives of the foregoing description.

Claims

1. A hydroelectric system for converting kinetic energy from water flowing off a roof of a building into electrical energy, the system comprising:

a turbine having a rotor;

one or more down pipes each having an upper end for receiving the water, each down pipe further comprising at least two channels, each channel extending from the upper end to a respective outlet, each outlet disposed to direct water flowing there from on to the rotor to cause rotation of the rotor in the same direction, the channels being configured in a manner so that at least one channel can overflow into another channel.

2. The hydroelectric system according to claim 1, wherein adjacent channels are provided with corresponding upper edges of progressively increasing height whereby water overflowing the upper edge of one channel flows into an adjacent channel.

3. The hydroelectric system according to claims 1 or 2, wherein the channels are provided with different hydraulic diameters.

4. The hydroelectric system according to claim 3, wherein the hydraulic diameter of a first of the channels into which water entering each down pipe initially flows is smaller than the hydraulic diameter of other channels.

5. The hydroelectric system according to claims 1 or 2, further comprising one or more gutters configured to receive water flowing from the roof and directing the water into each down pipe; and one or more roof channels, each roof channel disposed on the roof and extending diagonally from an upper portion of the roof to the gutter.

6. The hydroelectric system according to claims 1 or 2, further comprising a water flow regulating reservoir for at least one of the channels, the reservoir comprising an outlet in fluid communication with that channel, the outlet formed at a location below an upper edge of that channel and dimensioned to regulate flow of water collected in another reservoir, down that channel.

7. The hydroelectric system according to claim 6, wherein each reservoir is formed between a first wall of its associated channel, the first wall constituting the upper edge of that channel and a second wall spaced from the first wall, the second wall having an upper edge located below the upper edge of the first wall and wherein the outlet is formed in the second wall below the upper edge of the second wall.

8. The hydroelectric system according to claims 1 or 2, wherein the rotor comprises an Archimedes screw having an axis of rotation parallel to a direction of flow of water from the channels.

9. A hydroelectric system for converting kinetic energy from water flowing off a roof of a building into electrical energy, the system comprising:

a turbine having a rotor;

one or more down pipes each having an upper end for receiving the water, each down pipe further comprising at least two channels, each channel extending from the upper end to a respective outlet, each outlet disposed to direct water flowing there from on to the rotor to cause rotation of the rotor in the same direction, the channels being configured in a manner so that at least one channel can overflow into another channel; and

one or more water storage tanks in fluid communication with each down pipe for storing water that passes through each down pipe.

10. The hydroelectric system according to claim 9, wherein the one or more water storage tanks each comprise an overflow valve configured to open and release excess water to drain from the tank.

11. The hydroelectric system according to claim 9, wherein adjacent channels are provided with corresponding upper edges of progressively increasing height whereby water overflowing the upper edge of one channel flows into an adjacent channel.

12. The hydroelectric system according to claims 9 or 11, wherein the channels are provided with different hydraulic diameters.

13. The hydroelectric system according to claim 12, wherein the hydraulic diameter of a first of the channels into which water entering each down pipe initially flows is smaller than the hydraulic diameter of other channels.

14. The hydroelectric system according to claims 9 or 11, further comprising one or more gutters configured to receive water flowing from the roof and directing the water into each down pipe; and one or more roof channels, each roof channel disposed on the roof and extending diagonally from an upper portion of the roof to the gutter.

15. The hydroelectric system according to claims 9 or 11, further comprising a water flow regulating reservoir for at least one of the channels, the reservoir comprising an outlet in fluid communication with that channel, the outlet formed at a location below an upper edge of that channel and dimensioned to regulate flow of water collected in another reservoir, down that channel.

16. The hydroelectric system according to claim 15, wherein each reservoir is formed between a first wall of its associated channel, the first wall constituting the upper edge of that channel and a second wall spaced from the first wall, the second wall having an upper edge located below the upper edge of the first wall and wherein the outlet is formed in the second wall below the upper edge of the second wall.

17. The hydroelectric system according to claims 9 or 11, wherein the rotor comprises an Archimedes screw having an axis of rotation parallel to a direction of flow of water from the channels.