BG66163B1 - Multi-turbine hydropower system - Google Patents

Abstract

The multi-turbine hydropower system consists of a number of hydro turbines (1), which are consecutively mounted under an over-river horizontal gravity-flow water canal (2), each in the narrow portionof a rotationally symmetric pressure pipe (3), with a longitudinal section resembling a Laval nozzle. The power of each turbine (1) is controllable. The over-river horizontal gravity-flow water canal(2) is divided by movable sectional partitions (4). An electric generator (6) is directly coupled to the shaft (5) of each turbine (1). A safety grid (7) is placed at the outlet of each pressure pipe(3). The advantages of the multi-turbine hydropower system lie in its conformity with nature and the possibility to use a small water fall for energy purposes.

Description

Technical field

The present invention relates to a multi-turbine hydropower system for the production of mechanical energy by converting the kinetic energy of a water drop and in particular a small water drop. The resulting mechanical energy is used to produce electricity.

BACKGROUND OF THE INVENTION

It is not a novelty to use a water drop to produce energy through various types of turbines. For thousands of years, the energy of water falls has been transformed into mechanical energy. Rivers play a key role in maintaining the global ecosystem through the circulation of fresh water. By interrupting the rivers and introducing their water into the pipes, the river beds and the river valleys are drained and deserted. Estimating the damage from these adverse effects cannot always be done in exact numbers.

Although water-driven units have long been known in the art, there are a number of patents these days that improve not only the primary energy converters themselves, but also systems with such converters. A significant problem with low water falls is their low energy density. This does not allow efficient use of the known pressure turbines for high and medium waterfalls, such as the Francis and Pelton type. Kaplan turbines and Banks turbines are often used instead, as well as Darius turbines and others with vertical shaft axes. A common disadvantage of the types of turbines mentioned above is that they have relatively low speeds and therefore often need to be coupled with turbines to power generators, which will improve the electrical efficiency of the three-component turbine-multiplier-generator power unit.

From CA patents CA 2532734 and CA 2531708 are known multi-turbine systems for hydroelectric power plants with

Darius turbines and other similar machines that rotate across the water stream. A major disadvantage of such hydraulic power machines is that, for each revolution, their blades pass against the flow. And any movement of the blades overcoming the pressure of the water flow is extremely inefficient and significantly reduces the efficiency of each such machine and of course the system as a whole.

The disclosed material disadvantage of the two Canadian patents is avoided in Korea Patent No. KR 20010078994. In this case, the multi-turbine system is cascaded but requires a water fall of 20-30 tons. Such water falls are not classified as small. The disadvantage of such a cascade system is that it is extremely inefficient in really small waterfalls.

The closest known state of the art is disclosed in US patent 6,954,006 B2. The well-known multi-turbine hydropower system comprises a plurality of hydro-turbines mounted in series in the narrow portion of a pressure pipe, with a longitudinal section resembling a Laval nozzle (Venturi pipe). Each turbine is provided with one electric generator. A grate is fitted at the inlet of the pressure pipe. The known system cannot operate in a wide range of flow rates.

SUMMARY OF THE INVENTION

The technical problem the present invention seeks to solve is the utilization of the energy potential of low energy density water masses in river beds with small falls but large water flows that are currently underutilized. It is an object of the present invention to provide a multi-turbine hydropower system operating at low water pads with high electrical efficiency over a wide range of water flow variations without using closed pressure pipelines.

According to the invention, it is provided that each of the hydro turbines is of controllable power and is mounted in a separate pressure pipe, the turbines being arranged in series below one overhang horizontal without

66163 Bl pressure water channel. In this way, the system provides operation over a wider flow range and the ability to effectively manage the flow of each turbine. In contrast to US patent 6,954,006 B2 of the present invention, the turbines process a water jet directed by the diffuser but operate in an air environment that has about 1000 times less density and resistance. In the known system, the turbines operate in submersible mode, and at each turn of the turbines their blades pass against the movement of the water flow. And any movement of the blades overcoming the flow of the water flow is extremely inefficient and significantly reduces the efficiency. In the known system, the facility floats in the river bed and uses energy only for the limited amounts of water entering it. Much of the water masses pass under and past it without their energy being used. In the present invention, all water flow passes through the canal and its energy is used.

In one preferred embodiment, the turbines in the overhead horizontal unpressurized water channel may be arranged side by side or one after the other, and it may be separated by movable section barriers limiting the access of water masses to one or more turbines during the dry periods of the year. . This ensures a continuous overflow of water masses after the end of the canal. This is a prerequisite for maintaining fish migration and self-purification from floats.

In another preferred embodiment, the water quantities entering the channel are controlled by controlled barriers that, upon command, can stop the access of water to individual turbines and guarantee a constant overflow of water masses after the end of the channel for discharging floats and fish into the river after the facility. .

The advantages of the multi-turbine hydropower system according to the invention are the utilization of the energy potential of low waterfalls, the achievement of a high degree of conversion of the energy of the water flow into useful mechanical energy, its operation in a wider flow range in the super horizontal horizontal water channel through its modular mounting capability and its efficient flow control of each turbine. This control can be carried out by different means and in different ways, depending on the type of turbines used. For example, through section barriers that regulate the flow rate and partly the water fall; by changing the turbine speed by means of optimal channel flow redistribution; by changing the rotor and stator geometries of the turbines, depending on their type and in other ways and with other technical means.

The advantage of the invention is that the possibility of modular sequential installation allows the turbines to operate at optimum flow. Excess water quantities are absorbed by adding another turbine to the system or simply flowing over the end of the channel, rather than seeking to absorb their energy potential by over-opening the inlet openings of the turbines and hence deforming their efficiency curve. The operation of each of the turbines in the group is ensured in the optimum mode of operation, and thus maximizes the overall efficiency of the system under different operating modes, including emergency ones, with one or more turbines in the system not working.

The multi-turbine hydropower system according to the invention allows for high electrical efficiency at low water falls due to the higher revolutions of each turbine wheel due to its smaller diameter than in the case of one turbine at the same water fall on one side and from the simplified and highly efficient belt speed reducer to the generator, located on a lightweight structure above the above horizontal horizontal unpressurized water channel.

With the smaller rotor diameters of the turbines, the same power is achieved at higher speeds, at the expense of reduced torque, which allows them to be designed for lower power load, which results in lighter and lighter loads. cheap hydromachines.

The multi-turbine hydropower system of the invention has a number of environmental benefits.

At the beginning of the horizontal canal canal may not be the classical protection

66163 Bl of a net preventing fish from entering the channel and passing through the turbines, and such nets shall only be placed on the horizontal inlet coil of each turbine. This saves expensive and capricious cleaning systems for classic safety grilles. Adjusting the water flow by closing or opening the coils of an appropriate number of turbines provides water quantities constantly overflowing at the end of the channel. The fish from the elevation above the installation to the elevation after the installation shall be provided, as well as the existing position in such type of dams prior to the installation of the tubes.

The very passage of water through the turbine wheels significantly increases its turbulence and, when it enters the river bed, it additionally aerates the water, which favors the aerobic life of the river flora and fauna and prevents the development of anaerobic putrefactive processes in the river and prevents its entanglement.

The multi-turbine hydropower system according to the invention has the advantages of lower operational risks than any single-turbine system, including its ability to continue operating in the event of failure of one or more machines in the system.

At the same time, it also avoids a number of problems of the natural balance of river and riverine ecosystems. There is a safety grille at the inlet of each pressure pipe. The discharge of the closed pressure pipelines leaves the flow of water free and the river beds and river beds do not dry. The system will be installed on existing hydrotechnical facilities - low dams, overflows, etc. The canal will "hang" on vertical supports above the river bed immediately after the dam and will keep it hydrated through the turbines as it was before their installation.

The invention also has a number of other advantages related to the use of existing hydrotechnical infrastructure, existing electrical infrastructure, etc. Investment in construction and installation work for the installation of a multi-turbine hydropower system according to the invention is low not only because of the low cost of the turbines, but also because it is not necessary to build expensive water intakes, high dam walls, pressure pipelines, etc. The duct construction for the multi-turbine hydropower system ma requires minimal construction work on the river bed because it is above it. Even a lightweight metal structure can be used under fiberglass support troughs or classic reinforced concrete with supports and a U-shaped channel with openings for coffers.

The modular mounting principle enables the installation of module turbines in different sections of the water channels, in series and in parallel, depending on the natural and artificial structures available in them.

The choice of suitable locations for the placement of the system modules can also be made in view of the existing power infrastructure, in order to be able to export the generated electricity to the public network and to consumers.

Brief explanation of the attached figure

Figure 1 is a side view of a multi-turbine hydropower system according to the invention.

Examples of carrying out the invention

In FIG. 1 is a sectional view of an exemplary three-turbine hydropower system according to the invention. It is characterized by the fact that the turbines 1 are mounted successively under a single horizontal horizontal unpressurized water channel 2, each in the narrow part of a rotationally symmetric pressure pipe 3, with a longitudinal section resembling a Laval nozzle, wherein each turbine 1 is controllable.

The horizontal horizontal unpressurized water channel 2 rests on the bottom by means of supports. Water access to individual turbines is regulated by sliding section barriers 4. One shaft is directly coupled to the shafts 5 of each turbine 1. There is a grille on each inlet tube 3. By opening and closing the barriers 4, ensures the availability of water quantities that overflow at the end of channel 2, thus self-regulating, self-cleaning

66163 Bl from afloat and maintains the ability to migrate fish downstream.

Pressure pipes 3, resembling Laval nozzles, have the role of further increasing the dynamic pressure in front of each turbine rotor 1 and, at the same time, reducing the water pressure in the expanding portion of the pipe 3 after the turbine rotors. This creates a greater difference between the energy of the water stream before and after the rotors, which is transformed into useful energy. Placing the rotors in the narrow section of the tubes 3 aims at constructing smaller diameter rotors, respectively, at higher speeds and cheaper turbines, at the same power. In this way, they can be directly coupled to power generators and avoid the multipliers of revolutions, respectively, and mechanical cuts in them.

The use of the system according to the invention as a converter of water energy can be widely used in low waterfalls and dams of rivers and canals where known hydropower systems are extremely inefficient and / or unviable.

Each element of turbines, generators and other elements of the system can be made of inexpensive materials and with simple technologies. Rotary blades are made of fiberglass or metal. In the case of turbines for electricity generation, the power generators can be electrically controlled, electrically driven, synchronous machines with no brushes and contact manifolds and no expensive permanent magnets made of rare earth alloys.

Claims (2)

Claims 1. A multi-turbine hydropower system consisting of a plurality of hydro-turbines mounted in the narrow portion of a rotationally symmetrical longitudinal cross-section, resembling a Laval nozzle at the inlet of which a grille is installed, and each turbine is provided with one electric generator, characterized by the fact that each of the turbines (1) is mounted in a separate pressure pipe (3) and all pressure pipes are mounted under a raised horizontal water channel (2), and in the water channel (2), movable section barriers ( 4). A multi-turbine water-power system according to claim 1, characterized in that a grid (7) is mounted at the inlet of each pressure pipe (3).