Patent Application
20090097961
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.
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.
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.
An embodiment of the present invention will now be described by way of example only with reference to the accompanying drawings in which:
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 24a and 24b (hereinafter referred to in general as “channels 24”) that extend from the upper end 22 to respective outlets 26a and 26b (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 24a overflows into the channel 24b.
Upper and lower fixing rings 21a and 21b 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 24a and 24b are configured in a manner so that water entering the down pipe 20 initially flows through the channel 24a and out from the outlet 26a onto the rotor 18 to drive the generator 19. However in a heavy downpour the channel 24a may overflow into the channel 24b. The overflow water then flows through the channel 24b through the outlet 26b to turn the rotor 18 thereby providing further drive to the generator 19.
The overflow of water from channel 24a to 24b 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 24a, can subsequently flow into the adjacent channel 24b. In this regard, it can be seen from
In order to provide a controlled steady flow of water through the channel 24a, 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 30a of the channel 24a, 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 24a. 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 24a. Thus when water collects in the reservoir at a level below the slot 40 it flows into the channel 24a via the first outlet 34. The outlet 34 is dimensioned to provided a steady continuous stream of water down the channel 24a 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 24a 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 30a to flow down the second channel 24b.
The channels 24 may be provided with either the same or different hydraulic diameter. However, in a preferred embodiment the channel 24a may have a smaller hydraulic diameter than the channel 24b. The selection of the hydraulic diameter for the channel 24a, 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 24a.
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.
Referring to
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 24a and 24b. 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.
| Number | Date | Country | Kind |
|---|---|---|---|
| 200716830-5 | Oct 2007 | SG | national |
