WO2001073208A1

WO2001073208A1 - Hydroelectric power plant with penstocks installed on the bed of a river

Info

Publication number: WO2001073208A1
Application number: PCT/IB2001/000492
Authority: WO
Inventors: Paolo Mario Tosi
Original assignee: Paolo Mario Tosi
Priority date: 2000-03-30
Filing date: 2001-03-26
Publication date: 2001-10-04
Also published as: IT1315627B1; AU3950501A; ITMO20000061A1

Abstract

A description is given of a hydroelectric power plant (1) capable of exploiting a given difference in level (H) between the water intake point (A) and the point (B) at which the potential energy of the water is converted to mechanical energy which moves one or more generators (2) of electrical current, the power plant comprising one or more penstock tubes (3) located on the bed (4) of a river (5) or below the bed, in such a way as to follow the natural inclination of the bed, the one or more penstock tubes (5) having intake apertures (3i) located at the upstream end and outlet apertures (3u) located at the downstream end, next to which the said one or more generators (2) of electrical current are installed, the generators producing electrical current by exploiting the potential energy corresponding to the difference in level (H) between the intake (3i) and outlet (3u) apertures.

Description

HYDROELECTRIC POWER PLANT WITH PENSTOCKS INSTALLED ON

THE BED OF A RIVER

DESCRIPTION

The present invention relates to the technological field of hydroelectric power plants, in other words power plants which exploit a difference in levels between the point at which the water is taken in and the point at which the potential energy of the water is converted, usually by means of turbines, into mechanical energy which moves one or more generators of electrical current.

As is known, at the present time a power plant of this type comprises a dam which creates a reservoir into which flows the water of a river whose course is interrupted by the dam.

The water reaches a specified level in the reservoir, and its potential energy is used at the base of the dam, by making the water pass out of the reservoir through penstock tubes.

This type of hydroelectric power plant is, in the first place, very expensive because of the cost of constructing the dam, and furthermore it can only be built in mountainous districts or at least in a district having a sufficiently narrow valley to ensure that the water which fills the artificial reservoir created by a dam can accumulate to a specified level without occupying an excessively large surface area. This is one of the reasons why it is impossible to build hydroelectric power plants with sufficient power to meet local energy requirements in flat regions.

Moreover, even where hydroelectric reservoirs can be formed by means of dams, they spoil the appearance of the landscape and disrupt the ecological balance of the areas which they occupy.

With the aim of eliminating all the considerable problems associated with the construction of dams and the corresponding hydroelectric reservoirs, the inventor of the present invention has devised a new power plant, which is simple to construct, and which exploits the difference in levels between two points located along the bed of a river by positioning one or more penstock tubes which connect the aforesaid two points on the river bed, or immediately beneath it.

The difference in levels between the two ends of the tube, which is evidently filled with water over its whole length, makes it possible to use the potential energy of the height of the water column equivalent to the difference in level between the intake aperture, located at the upstream end, and the outlet aperture, located at the downstream end, where this energy can be converted by known methods into mechanical energy which can drive one or more generators of electrical current.

Thus the inventor has devised a hydroelectric power plant as described in the precharacterizing clause of the attached Claim 1, characterized by the characterizing clause of the said claim. A description of a preferred example of embodiment of the hydroelectric power plant according to the invention will now be given, although this example is not limiting or restrictive in respect of any different embodiments which can be produced by a person skilled in the art on the basis of the teachings of the aforesaid Claim 1.

In the course of this description, reference will also be made to the attached drawings which show: in Figure 1, a schematic lateral view of the said example of embodiment of a power plant according to the invention, in which the penstock tube is installed on the bed of a river; in Figure 2 , a schematic plan view of the power plant of Figure 1. Before the aforesaid description is given, it must be pointed out that the inventor has based his invention on his opinion that, in a smooth tube of regular section installed on the bed of a river with curves formed in the most suitable way, the water passing with a practically laminar flow along a path of a given length within the tube undergoes fewer energy losses due to turbulence and friction than the water in the river passing along the same path. Given this premise, we can consider Figures 1 and 2, which show how a hydroelectric power plant 1 according to the invention comprises a penstock tube 3, installed on the bed 4 of a river 5 over a total length L, and provided with an intake aperture 3i located at the upstream end and an outlet aperture 3u located at the downstream end.

The difference in levels between the centres A, B of these apertures 3i, 3u has a specific height H, and the water passing through the penstock tube 3 can transfer its corresponding potential energy to a mechanical device of a known type, located at the said outlet aperture 3u, which drives one or more generators of electrical current (a single generator, indicated by the number 2, in the present case). This generator, which is integral with the mechanical device (not shown separately in the drawings), can be located, as shown in Figure 2, immediately above the bed of the river 5, still at the level of the said point B of the outlet aperture 3u. For periods in which the energy produced exceeds the quantity required, the inventor proposes the construction of a tank 7, with its base 7e positioned essentially at the same level as the said outlet aperture 3u, into which the excess water can be made to flow before it reaches the outlet aperture 3u, by means of a number of ducts 6 provided with shut-off valves 6t which are preferably remotely controlled.

The said excess water, reaching a desired level K in the said tank 7 (which can be of the open or closed cycle type) thus forms a reserve to be used for the said generator 2 or for another supplementary generator of electrical current at times of peak energy demand.

When the said level K has been reached in the tank 7, if the water is not to be used, the aforesaid valve 6t is closed, and the excess water, if it cannot be used to drive the generator 2, can be returned to the river 5 by opening another discharge valve 8 in a portion 8 of duct with the outflow aperture directed downstream.

Thus a hydroelectric power plant 1 which is versatile, and less expensive and more environmentally friendly than power plants which use reservoirs created by dams, is produced. Thus the declared object of the inventor is achieved.

Claims

1. Hydroelectric power plant (1) capable of exploiting a given difference in level (H) between the water intake point (A) and the point (B) at which the potential energy of the water is converted to mechanical energy which moves one or more generators (2) of electrical current, characterized in that it comprises one or more penstock tubes (3) located on the bed (4) of a river (5) or below the bed, in such a way as to follow the natural inclination of the bed, the one or more penstock tubes ( 5 ) having intake apertures (3i) located at the upstream end and outlet apertures (3u) located at the downstream end, next to which the said one or more generators (2) of electrical current are installed, the generators producing electrical current by exploiting the potential energy corresponding to the difference in level (H) between the intake (3i) and outlet (3n) apertures.

2. Power plant according to Claim 1, provided with one or more by-pass ducts (6) branching from the said penstock tube (3) and capable of diverting a variable quantity of water before it reaches the said generator(s) (2) of electrical current, directing it into a tank (7) having its base (7e) positioned essentially at the same level as the said outlet aperture (3u) .