BG109645A - Zero head water turbine - Google Patents

Abstract

The zero head water turbine has one or more blades (2) peripherally mounted on a common shaft (3). The shaft (3) is located horizontally and transversally to the water stream, each blade (2) resembling a hollow aerofoil open in its elongated portion, whereat the blades (2) are helically twisted around an imaginary cylindrical surface described during rotation by the inside of the blades (2) on the side of the rotor shaft (3) of the turbine (1). The turbine (1) may consist of a number of separate coaxial rotors of different diameters that are mounted on a common vertical shaft (3) or on two coaxial shafts rotating in the same or in different directions, while the blades (2) of the turbine (1) may be of variable widths and profiles lengthwise. The turbines (1) may be combined in a common installation and, through a common transmission and multiplication of the revolutions, actuate one or more electric generators / alternators of a hydroelectric power station at a free-surface flow.

Description

Technical field

The present invention relates to an unpressurized water turbine for the production of mechanical energy by converting the kinetic energy of sea and ocean tides, water waves, river currents, and other unpressurized fluid flows. The resulting mechanical energy is used to produce electricity, pump water, compress gaseous and liquid fluids, deploy flywheels, and other energy conversion and storage devices.

BACKGROUND OF THE INVENTION

It is not a novelty to use the kinetic energy of naturally moving fluids: the flowing water of rivers, sea and river currents for useful work. For thousands of years, river and other water currents have been rotating water wheels that transform the flow energy into mechanical energy of the wheel shaft. Although water-wheel-driven units are widely known in the art, there are a number of patents these days that improve not only the primary energy converters themselves, but also systems and units with such converters included.

From Canada Patent No. CA20042484293, a vertical axis turbine for non-pressure water currents is known. This and all other vertical axis water turbines are most often located below the water near its surface. It is known that the surface water flow is at the highest velocity, but it decreases rapidly with increasing depth. At the bottom, the speed is practically zero. And the horizontal forces acting on the blades of the vertical axial turbines are: · · · · · · · · · · · · · · · · · · · · ·

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proportional to the square of the velocity, which means that if the top speed of the blades of the vertical axial turbines is water velocity about 1.4 times higher than that of the lower part of the blade, then the horizontal load on the upper edge of the blades will be about twice as large as on its lower end. This difference causes highly asymmetrical loads in the blades, which has undesirable mechanical consequences. In principle, all turbines whose shafts are vertically in the flow experience such unwanted loads not only on their blades but also on their shafts, as well as on the whole structure that supports the turbine.

Patent Publication No. W02006030190 proposes a vertically axial Darius turbine whose blades are circumferentially spaced about the circumference of the rotor and can be twisted during rotation. This, and all other types of Darius machines, rotate due to the aerodynamic / hydrodynamic force generated by the rotation of the rotor blades, which have transverse profiles that resemble airplane wings.

Helical turbines described in US Patent No. US2001000197 work in the same way.

The disadvantages of turbines according to the last two cited publications, and of all the others, are that they are ineffective at low flow rates and are therefore not intended to operate at sea waves, for example, where the speed of the water when raising and lowering the wave is low. In this case - twice in one wave period the speed is zero (at the highest and the lowest point).

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SUMMARY OF THE INVENTION

It is an object of the present invention to provide a pressureless water turbine that is efficient at low speeds of the fluid flowing around it, to test low loads on the blades, shaft and all its supporting structure and to be of low cost.

The main objective is achieved by a non-pressure water turbine with one or more peripherally mounted blades on a common shaft, characterized in that the shaft is horizontally and transversely flowing, and each blade resembles a hollow aircraft wing which is open in its elongated part in which the blades are helically twisted around a thought cylindrical surface, described by rotating the inside of the blades from the rotor shaft of the turbine.

In one preferred embodiment, the number of blades is odd and they are uniformly and symmetrically mounted around the vertical shaft of the turbine.

In another preferred embodiment, the number of blades is even, with a solid blade symmetrically opposed to each hollow blade symmetrically mounted resembling a helically twisted airplane wing.

In another preferred embodiment, the turbine may be composed of a plurality of separate coaxial rotors of different diameters mounted on one common shaft.

In another preferred embodiment, the turbine may be composed of a plurality of separate coaxial rotors of different diameters mounted on two coaxial vertical shafts.

In another preferred embodiment, the turbine blades may have variable widths and length profiles.

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The advantages of a pressureless water turbine according to the invention are to achieve a high degree of conversion of the kinetic energy of the fluid stream into useful mechanical energy at low water flow velocities, with oscillating water flows such as ebb and flow, and its effective the operation at higher turbulence of the stream and its possibilities for the construction of installations with multiple such turbines (modules), arranged side by side, one after the other, one below the other in the stream, as well as with different combos nations of the placements they describe. The horizontally positioned turbine shaft, transversely to the stream, enables all efforts on the blades, as a result of their resistance to the water flow, to be converted mainly to the torque of the turbine shaft and to less load the turbine blades themselves. With the horizontal position of the shaft, the asymmetrical loading of the blades along their length is greatly reduced.

Installations with turbine modules according to the invention have a lower cost per unit of converted power, because the power of each turbine is proportional to its mass, and therefore approximately, to the cost. And small-diameter turbines rotate faster, reducing losses at multiplying their speeds, and also eliminating multipliers, whereby the turbine shaft is coupled directly to a low-speed power generator / alternator.

The low frontal resistance of a non-pressure water turbine according to the invention allows it to be mounted on existing supports such as various types of bridges, pier walls, pontoons and other structures and structures and floating platforms.

The unpressurized water turbine according to the invention can find application within a group of such general-purpose turbines. · · · · · · · · · · · · · · · · · · • · · · · · · · · · · · · · · · · · · ·

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and a generic generator / alternator, for example. This will further reduce the cost of energy received.

Such a group of turbines connected to power generators is an unprecedented hydroelectric power plant. It has a number of environmental benefits that I do not dwell on here. I will only note that erosion along river banks, small and large rivers, is most often caused by fast currents. For rivers running from west to east in the northern latitudes, coriolis forces further intensify the currents along their right shores. This is also the case with long stretches of the Danube River, where it is constantly shifting south because the watercourse erodes the southern shore more intensely than the north. If hydroelectric power stations are made according to the invention in such and similar places, two synergistic goals can be achieved simultaneously:

• to divert the erosion flow to the hydroelectric power plant and thus • some of its kinetic energy will be utilized instead of eroding the coasts, dykes and flooding the river areas at high water levels.

Investments for construction and installation work for the installation of hydroelectric power plants with turbines according to the invention are low not only because of the low cost of the turbines, but also because they do not need to be constructed, water mains, dams or dams, pressure pipelines, etc. At the same time, a number of environmental problems are avoided.

The low capital costs of constructing hydropower plants with turbines according to the invention, their operational facilities and their environmental benefits make them a highly competitive investment for any hydropower site where the kinetic energy of free-flowing water is used to generate electricity.

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Brief explanation of the accompanying drawings

Figure 1 is a schematic representation of a three-blade unmanned water turbine according to the invention.

Figure 2 shows a pontoon installation for a two-turbine hydropower plant according to the invention.

Examples of carrying out the invention

Figures 1 and 2 give two examples respectively. Figure 1 shows a non-pressure water turbine 1 according to the invention, mounted under a pontoon.

Figure 2 shows a two-turbine installation mounted under a pontoon platform anchored by ropes 4 to the anchors 5 at the bottom.

The use of the turbine according to the invention as a converter of kinetic energy of water flow can find wide application in various devices in which the energy of water flow is converted to other useful energy.

The unidirectional rotation of the turbine according to the invention with oscillating water flows, such as tides and sea waves, make the turbine a relatively simple and reliable machine that can operate in a wide range of flow rates and with high turbulence therein. The latter allows the turbine rotors to be installed close to each other within a single installation. The recommended distances between them are about one rotor diameter.

The optimum angles of rotation of the turbine blades according to the invention are given in the table below:

Number of shovels 2 3 4 5 Torsion angles 0-180 ° 0 -120 ° 0-90 ° 0-70 °

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Basic dimensions of the turbine blades according to the invention.

Width of shovels 100% 100% 100% Number of shovels 2 3 5 Greatest thickness of shovels ί 23-27% 21-24% 18-21%

General ratios of the thicknesses of the transverse profiles between open hollow and dense turbine blades according to the invention:

Number of shovels 2 3 5 Maximum thickness of open shovels C ---- 100% 100% 100% Maximum thickness of wing-like blades -118% -115% -113%

Each element of the turbine is inexpensive and can be manufactured from inexpensive materials and with simple technologies. Rotor blades are made of fiberglass, fiberglass or metal. In the case of using the turbine to produce electricity, the electricity generators purchased directly to the turbine or through a speed multiplier can be electromagnetic synchronous machines with adjustable excitation, without brushes and contact manifolds, and without expensive permanent magnets made from rare earth alloys metals.

Claims (6)

Patent Claims 1. An unpressurized water turbine (1) in Figure 1, with one or more peripherally mounted blades (2) on a common shaft (3), characterized in that the shaft (3) is horizontal and transverse, and each blade (2) resembles a hollow aircraft wing which is open in its elongated portion, the blades (2) being helically twisted around a thought cylindrical surface, described by rotating the inside of the blades (3) from the rotor shaft (2). the muzzle (1). 2. A pressureless water turbine (1) according to claim 1, characterized in that the number of blades (2) is odd and they are uniformly and symmetrically mounted around the vertical shaft (3) of the turbine (D- A pressureless water turbine (1) according to claim 1, characterized in that the number of blades (2) is even, symmetrically mounted to each hollow shovel (2) symmetrically a tight blade resembling a helically twisted airplane wing. 4. A pressureless water turbine (1) according to claims 1, 2 and 3, characterized in that the turbine (1) consists of a plurality of separate coaxial rotors of different diameters mounted on one common shaft (3). An unpressurized water turbine (1) according to claims 1, 2, 3 and 4, characterized in that the turbine (1) consists of a plurality of separate coaxial rotors of different diameters mounted on two coaxial vertical shafts. 6. A pressureless water turbine (1) according to claims 1, 2, 3, 4 and 5, characterized in that the blades (2) of the turbine (1) have variable widths and profiles along their length.