GB2517522A - The Butkus Turbine - Google Patents

Abstract

A tidal or river turbine uses an under shot paddle wheel 9 mounted in a duct 10, 11. The ducts 10, 11are tapered to accelerate flow onto the blades of the paddle wheel 9. The unit may be factory assembled or supplied in kit form. The paddle wheel may drive a generator via a ring gear and pinion (figure 5). The generator may be remotely located on shore and driven by a hydraulic or mechanical transmission. The assembly is mounted on the sea or river bed to avoid shipping, ice etc, and does not affect its surroundings visually.

Description

Title: The Butkus Turbine A hydro generator arrangement for underwater placement.

Tide Power

Field of invention

The invention relates to an apparatus for extracting energy from tidal and river flows.

Background to thc invention

Tidal power modules offer greater advantages over other wave and tidal power devices.

Tides are regular and predictable. Where as wave modules depend essentially upon weather conditions. A water turbine is most efficient at a pacific water speed. if the velocity changes, the efficiency falls dramatically. This is not the case for a water wheel which maintains its efficiency over a much wider range of flow rates. The relative speed of the different areas of the paddle wheel will be different and vary as a function of the radial distance of the paddle wheel blade with respect to the hub. The locations for other tidal devices are generally in high flow rate tidal streams. The Butkus Turbine is designed to operate in a low flow tidal stream. 2 knots (1.028 meters per second). However, it can run up to 8 knots (4.114 meters per second).

Several major tidal power schemes have been constructed in river estuaries, but these have involved barrages and major engineering works, they risk permanent changes to the environment in areas of importance to wildlife. They are extremely costly to build and increasingly difficult to find suitable locations for such schemes. This system allows cheap cost effective construction with easy transportation and siting, needing no large engineering works.

Sitting on the seabed, the modules are free of any ice or other large floating objects.

Being invisible it bares no detriment to its surroundings and location.

However, being sited on the seabed, screen guards are fitted to each module to prevent large fish and debris passing through, where allowing small fish and debris to pass through.

When sited vertically it is self cleaning, therefore, no silt build up.

Transportation wise, the modules can be easily relocated by road, train, as there are no fixed structures. The offshore siting can be achieved by using a floating module which then attached to the turbine and towed into position and then anchored. This method is a cost effective with minimal operational requirements.

The have been several proposals for tidal power devices that have similar low environmental impact. For example; GB2337305 relates to a large vertical access rotor with aerofoil blades to cause rotation of the floating structure relative to a tethered ring cam pumping system.

RU2160848 relates to a large horizontal axis rotor similar to a paddle steamers which is fitted onto a floating bridge.

W02005/035977 relates to a tidal generator with pivoting baffles directing the flow to one side of the rotor.

GB2445 284A relates to a turbine rotor with multiple blades held in a floating chamber.

EP2136072 Al a multi aerofoil bladed rotor in a duct system.

The Butkus Turbine invention seeks to provide a simple and cost effective apparatus for cxtracting energy from a flowing fluid, i.e. water, sewage waste, etc.

Introduction to the Invention.

According to the present invention, there is provided a tidal power apparatus, comprising of a rotor located in a barrel with inlet and outlet ducts.

The Butkus Turbine, will be held in position by anchors fixed into the seabed sand!rock.

The water can enter the Butkus Turbine from either direction. The water enters the inlet duct (10 & 11) this increases velocity and decreases the pressure, having a unequal angled venture, the water is directed onto the rotor blade (16) at a specific angle depending on the inlet speed of the water. The water, when hitting the blades at a predetermined angle, then turns the rotor which the blades are attached to. The power outlet of the rotor shaft (19) can then be harnessed via a direct drive, gear boxes, drive shaft or chain and sprocket system. This then can be connected to various equipment (water pumps, hydraulic pumps) to transfer the power ashore to be converted into electrical energy.

The rotor is preferably a undershot paddle type turbine of eight blades. The blades are of a size 25% of the overall diameter of the rotor. These are attached to rotor discs by mechanical means. This allows easy replacement of blades when required. In certain conditions anodes can be attached to slow the electro magnetic reactions which again can be easily replaced. The main shaft is mounted into the barrel casing using two bearing assemblies. The gap between the blade and the shaft allows fish and other articles to pass through the rotor with ease.

The barrel is uniformed in shape allowing free movement of the rotor. The barrel is mounted to the top and bottom of the turbine side walls by either welding or mechanical methods.

Inlet and outlet ducts are made of the same material as the barrel. These are fitted to the side walls in the same manner as above. Each duct comprises of two plates inner/outer. The inner duct plate is set at an angle and jointed to the barrel by means of welding or mechanical methods. The outer duct plate is set at an angle and joined to the side by means of welding or mechanical methods. The angle at which these are set at can be varied to the location and water inlet speeds. The removable panel is made of the same material as the barrel and ducts which interconnects between both outer duct plates. This allows easy access to the turbine blades and anodes for routine maintenance. The overall shape of the inner/outer duct plates form a type of venturi.

Introductions to the drawings

The apparatus consists of a top and bottom side-plate with a rotor mounted between them, as follows detailed description of the illustrated embodiment, The basic build of the Butkus Turbine can be constructed from various materials, i.e. wood, plastic, steel, and fero concrete. Factory produced or flat pack -kit form. Fig 1

This is a drawing illustrating the basic outline of the apparatus with the matched lines showing all parts of the body assembly -Figs ito 7.

(1) & (2) side wall. Made from non-flexible material with opening for the main shaft to protrude and fixings for the bearings.

(3) barrel casing. This is made from a rolled non-flexible material (factory format) in one section, or in sections which when located together form a barrel (kit form).

(6) & (8) outer ducts. These comprise of non-flexible material.

(7) & (5) inner ducts. These comprise of non-flexible material.

(4) outer removable panel. This allows easy access to rotor and blade assemblies. These comprise of non-flexible material. Fig 2

This is a sectional vies showing rotor (9) The inlet/outer ducts (10) & (Ii) which have differential angles.

(12) being Ii degrees.

(13) being 5 degrees as required for a 4 knot tide flow. Both (12) & (13) can be altered to increase or decrease its speed efficiency in relation to tide flow.

The rotor (9) is supported using bearings (14) & (15) which are attached to the turbine side walls. The output drive can be taken by different ways as seen in Fig 4 & 5 which is a drive chain or gearing mechanism. Fig 6 utilises two 90 degree reduction gearboxes connected via a drive shaft. Fig 3

The illustrated turbine consists of eight blades (16) which are attached to the rotor plates (22) using counter sink bolts (17) The rotor is attached to the main shaft (19) using a boss assembly (18) by counter sunken bolts (20) and grub screws (21). Fig 4

This is one method of transferring the rotary movement of the turbine (22) to a position where it is available to be used to create power to run compressors, water pumps, water/electrical generators.

A drive disk (23) is attached to one of the rotor plates (22) using counter sunk bolts (24). the drive disk is made from two sections and jointed together (25). The outer edge being with the same size as the diameter of the rotor with blades attached (16). This can be a machined tooth gear wheel or a chain which can be attached to the disc as in Fig I Fig 5 This is one type of the design to provide an increase of revolutions per minute of the rotor without using reduction gearboxes This reduces the power lost through worm gearing or sprockets. The drive (23) is made of two segments and joined (25) using a step joint system and bolted together (25a) & (25b). It is mounted onto one or both rotor plates (22) via the mounting arms with counter sunk bolts (26). The outer edge can be a machined rack or a one inch pitch chain with adaptor lugs welded (27) A sprocket or pinion wheel (28) is mounted on the outside of the barrel casing (29) which is connected to the drive system (31). At 50 rpm rotor speed the drive output would be 1500 rpm. Fig 6

This is another method as in Fig 5 which is a means of transferring the rotational power from the rotor shaft (19) to the drive system (31). Using 90 degrees reduction gearboxes (28) & (29) connected via a drive shaft (30). This system is mounted onto the side or sides of the turbine side walls (29). The reduction gearing will increase the rpm from 50 rpm to 1500 rpm which is the desired rpm to operate the drive system and run compressors, water pumps, water/electrical generators. Fig 7

Rotor blade assembly is a flat plate (16) with top and bottom edges (31) formed to 90 degrees (32). two holes at top and bottom (33) allow easy fitting and removal to the rotor blades in situ via the removable access panel (4). A chamfered edge has been formed (34) to reduce cavation in the barrel body. Anodes can be fitted to reduce corrosive deterioration (35).

Summary

Electromagnetic flow meters can be fitted to the duct in the venturi region to measure flow speeds, additionally meters will monitor the rotation of the turbine, i.e. clockwise or anti-clockwise. The data can be communicated ashore via appropriate cables or pipe lines. The control system is arranged to calibrate the performance of the apparatus in three ways. Firstly, the water speed entering the venturi. Secondly, the speed of the rotor (revolutions per minute).

Thirdly, the output torque.

The power output of the rotor shaft is slowed down by a variable resistive torque which is controlled to optimise the maximum output production.

The overall control strategy is to optimise the electrical generation by maximising the output throughout the tidal cycle, in which flow speeds can vary considerably at different times of the tide and will reverse twice daily.

Anchorage of the Butkus Turbine will be by way of vacuum anchor system on sand/mud seabed or plates anchor using fixing mechanism to a rock seabed.

The transfer of power either by electrical or hydraulic means from the turbine to a collection point ashore would lay on the seabed or buried below, a quick release means would be incorporated on the transfer lines to allow easy and swift changeover of turbine units as required for servicing/repair, whilst submerged.

Suitable locations could be rivers, estuaries, factories/sewage farms or working adjacent to offshore wind turbines and connecting the output from the device into the grid via the wind turbine supply chain, thus saving power loss transferring the Butkus Turbine power ashore. It is anticipated that a number of water turbines would be interconnected (eight) making an array.

Each offshore wind turbine could have arrays sited on the seabed either side and connected into the electrical output systent This would provide additional electrical power to compensate when there is a lack of wind.

A twenty year design life could be achieved, using turbines (eight) in an array, if any of the modules require changing due to repair/maintenance, this can be achieved while temporarily losing a small proportion of the output generating capacity.

It is envisaged that the Butkus Turbine in accordance with the invention is of four basic sizes. ilowever, alternative sizes could be built.

Size 1. 2m long x 1.75m wide x 0.37m high.

Size 2. 4m long x 2.Sm wide x 0.75m high.

Size 3. 6m long x 4.24m wide x 11 2m high.

Size 4. Sm long x Sm wide x I.5m high.

A size 4 Butkus Turbine sited at a given location of a 4 knot tide would thus generate a predicted 8 Sw of power.