| WO/2013/061310 | VERTICAL AXIS WIND ENERGY CONVERTER |
| JP4090809 | Windmill |
| JP2007527477 | Generator |
| Claims A controllable Omnidirectional wind speed accelerator for increasing the power output from any wind turbine consisting of: a number of radial vertical fins and sloping vanes with a conical or curved top 'roof designed to provide laminar surface air flow surrounding either a horizontally or vertically mounted wind turbine, with its catchments 'mouth' area substantially larger than its throat area, therefore increasing its wind speed before entering the turbine. A controllable Omnidirectional wind speed accelerator as claimed in claim 1 wherein the top roof enclosure contains a central vertical air duct, resulting in a lowering of air pressure behind the turbine blades creating a greater pressure difference between the front and back of the rotor blades and therefore a further increase in wind speed. A controllable Omnidirectional wind speed accelerator as claimed in claim 2 wherein a partially open rotating central cylinder is sited within the core of the device in front of the rotor blades, which is controlled by an external vane so that the open face is always in the direction of the wind, thus creating a more efficient pressure difference and therefore a further improvement in wind speed. A controllable Omnidirectional wind speed accelerator as claimed in claim 3 wherein the partially open rotating cylinder, drastically reduces the downwind sound volume from the device as airflow (and sound waves) are directed upward through the central duct. A controllable Omnidirectional wind speed accelerator as claimed in claim 4 wherein the net increased wind speed can result in smaller diameter rotor blades for an equivalent power output. A controllable Omnidirectional wind speed accelerator as claimed in claim 5 wherein the mast of the device is a lifting ram, which enables the device to be raised or lowered behind a sloping screen 'wall', this allows a method of control both by increasing its height and thus its exposure to higher wind speeds or by lowering its speed by shielding the device behind the 'wall' , thus maintaining the correct speed to suit the generators rated or maximum power output capacity, thus raising its overall capacity factor. A controllable Omnidirectional wind speed accelerator as claimed in claim 6 wherein the device can be completely lowered behind the screen 'wall' in gale force wind conditions, which would protect the turbine inside and greatly extend its life and provide more scope to site these in more hostile or exposed locations i.e. desert sites. A controllable Omnidirectional wind speed accelerator as claimed in claim 7 wherein photovoltaic cells are attached to the screen wall, thus extracting solar energy even if there is little or no wind energy available, providing a more constant and greater supply of power. A controllable Omnidirectional wind speed accelerator as claimed in claim 8 wherein photovoltaic cells, can be rotated around the screen wall which is controlled to provide the best configuration to obtain the maximum energy available from the sun, based on the suns location. A controllable Omnidirectional wind speed accelerator as claimed in claim 9 wherein any number of 'WSA's, can be stacked vertically above each other, which would greatly increase the power output without any increase in its site's footprint or with any negative effects of wind shade, normally associated with multiple wind turbines. A controllable Omnidirectional wind speed accelerator as claimed in claim 10 wherein additional ground or roof level solar reflectors are included, which would intensify the solar energy reaching the PV cells or solar arrays, thus increasing their power output and reducing their payback time. A controllable Omnidirectional wind speed accelerator as claimed in claim 11 wherein it incorporates sound absorbing or damping measures included within its structure, acoustically designed to match the frequency output of each type of turbine used, this would radically reduce the noise output and should ease locating the turbine in more sensitive areas in relation to noise. A controllable Omnidirectional wind speed accelerator as claimed in claim 12 wherein a secondary smaller wind turbine is placed within the vertical air duct, thus extracting still further energy from the wind, before the air passes through any sound / acoustic buffers. A controllable Omnidirectional wind speed accelerator as claimed in claim 13 wherein would by the very nature of its design eliminate light and radar flutter, which should ease locating the 'WSA' in more sensitive areas in relation to shadow casting or radar interference. A controllable Omnidirectional wind speed accelerator as claimed in claim 14 wherein would by the very nature of its design eliminate the need to have large numbers of turbines on any one site due to its increase in power output, therefore reducing the negative effect on the landscape in more sensitive areas in regard to planning. A controllable Omnidirectional wind speed accelerator as claimed in claim 15 wherein the complete structure of the device is so designed that the total loads are distributed over a greater base area footprint, thus keeping bearing stress to a minimum, to allow sitting on flats roofs of multistory buildings where wind exposure is greatest. |
This invention relates to a turbine arrangement and in particular to a turbine arrangement which permits improvements to be achieved in the efficiency or effectiveness of power generation.
Before we look into this invention in detail, we need to understand how Wind Turbines work at present, what problems and inefficiencies there are, and how this system aims to greatly improve on.
Elements, problems and efficiencies of a typical system
1. The wind speed - if you were to double the wind speed you would get 2 (i.e.
8 times more energy from the wind).
2. The frequency of the wind speed (the longer the wind blows at greater speed the better).
3. The catchment area of the blades (i.e. diameter they can sweep out).
4. The Installed Power and efficiency of the generator, invertors and the amount of power loss in the cables.
5. The rated, cut in and cut speeds of the Turbine.
6. The location of the turbine - The more windy the site the better.
7. The position on site - Positioning the turbine clear of any obstructions which would slow down the air flow or cause turbulence.
8. The hub height is very important - where there are greater wind speeds. 9. The noise, radar echo and light flutter caused by the blades.
10. Turbine must not be too far away from the main network supply.
The net effects of the above elements combine to give a capacity factor - for the chosen turbine at a given location and hub height.
Currently, for a typical installation, this produces a capacity factor < 25%.
The solutions currently used to achieve a desired output are:
1. To achieve the Installed power of one turbine, you would require at least 4 turbines of equal capacity, having an adverse effect the countryside, (taking up large amounts of space as they cannot be located within their wind shade zone), and would require four times the expense.
2. To locate the turbines only in very windy locations, including offshore.
3. To have very large turbines at ever increasing height.
4. To locate the turbines away from residential areas, which would be affected by the noise?
5. To locate the turbines away from heavy air traffic zones.
6. To locate the turbines close to a main generating network supply
7. To improve the efficiency of the electrical elements.
8. To reduce drag on the blades to make them more efficient and more quiet. In accordance with the present invention there is provided a turbine arrangement as defined in the appended claims. Such an arrangement is advantageous in that it addresses many of the issues set out hereinbefore whereas in the typical arrangement:
• Lttle attempt is being made to control the wind speed before it enters the turbine, i.e. increasing its speed (up to its rated speed) or reducing its speed (below the cut of speed). · Nor is the wind turbine combined with a photovoltaic (PV) Array so that energy can be produce even if there is no wind.
By combining the arrangement of this invention with individual solar energy evaporator's incorporation with heat pumps, it could be possible to provide 100% of the energy for the power and heating, a completely environmentally friendly, Green CHP system can be achieved.
The invention will further be described, by way of example, with reference to the accompanying drawings, in which:
Figures 1 to 7 illustrate, diagrammatically, a turbine arrangement in accordance with an embodiment in a number of different operating conditions; Figures 8 to 20 are representations of the design parameters for differing sizes of vertical axis wind turbines.
The 'DPWSA' (dual purpose wind speed accelerator) is a 'bespoke designed' independent fixed structure that surrounds the normal freestanding turbine. The design incorporates the average wind speed at the site, the cut in, rated and cut our speed. The design would accelerate its speed to the optimum speed to vastly improve its capacity factor. Due to the funneling effect of the wind any sound generated would be more focused therefore the design can incorporate sound absorbing panels, which would be designed to absorb the sound at the correct frequency with the net effect of reducing the sound output by half over the normal turbine.
There are two types of design - The standard design and the variable design, either site onshore or offshore.
The standard 'fixed' design (figs. 4-6) will only increase the wind speed entering the turbine, whilst the variable design (figs. 1-3, 7) could be used to reduce the wind speed, providing even greater capacity factors, although more costly to construct and maintain.
The net effect of this invention are illustrated by way of the calculations set out in Schedule A appended hereto. In its simplest construction, it would simply consist of a structural cladding system designed to capture a greater amount of wind energy than that provided by the swept area of the blades alone, this captured wind is then focused into a reduced area and the addition of a tapered roof with central ventri duct giving a corresponding net increase in wind velocity as shown.
A metal framed structure clad with metal would be used for medium to large sized turbines.
An add-on to the 'WSA' is a tapered 'skirt', which can conceal or partial conceal the 'WSA', if the WSA is lowed below this screen it will effectively reducing the amount of inlet airflow, thereby regulating the speed of air at the turbine blades, optimizing the speed to suit the rated output of the turbine.
Secondly, by combing a PV array to this skirt which can track the suns path 'in the horizontal direction' would add to the renewable energy output providing the maximum output in summer months, when wind energy is reduced. During gale force winds the 'WSA' could be completely hidden behind the skirt providing protection to the generator and blades. The 'WSA' mast would be hydraulically operated and controlled by a computer programme and would monitor via sensors the wind speed and direction. The computer programme would make all necessary adjustments automatically to provide the maximum possible power output. T/GB2011/001682
The main advantage is the power increase
A reduction in turbines for the same power output is obtained.
An earlier payback is obtained.
The design could be made to reduce noise pollution
The fins enclose the rotating blades and will help reduce or completely remove the radar echo.
A fewer number of turbines will retain the views of the countryside.
The combined system would not need to rely on the grid for reserve power as this system would have a 100% (rated output of turbine) capacity factor.
The incorporation of PV Solar panels within the 'skirt' enable power to be generated even when there is no wind energy available
Wind and solar energy are the major sources of renewable or 'green' energy production. Windmills and solar farms are used all over the world in order to harness the power from the environment. On average, about 75% of the total wind energy we receive every year (in the UK) comes between November and April, (which is the majority of the heating period), when solar power is at its least effective, so the two systems are complementary. Large areas of the world appear to have mean annual wind speeds below 3m s, and are unsuitable for wind power systems, and almost equally large areas have wind speeds in the intermediate range of 3-7m/s, where power may or may not be used. These areas are mainly unexploited for harnessing the wind energy, because technology does not serve efficiently this purpose yet.
Currently those areas with mean annual wind speeds exceeding 7m/s are the most technically viable for power generation.
The annual amount of solar power reaching Northern Europe on horizontal surfaces is 3.1 - 3.8 GJ/m 2 even more power on surfaces 'normal' to the suns rays and also more on vertical surfaces when the suns altitude is less than 45 degs. This invention extracts energy from the sun wherever the sun is located in the sky. Other places of the world have greater solar power reaching its surface where this invention becomes even more economically viable.
Also this invention seeks to provide those areas with low wind speeds, a pioneering way to harness efficiently the energy from the environment and hence make clean energy cost effective and increase its capacity factor. This invention also allows for fluctuating power supply with the energy demand needs. Energy demand is higher during the 17 hrs of daytime with concentrated peek periods within this time; also more energy is consumed within the 33 weeks of the heating season (UK).
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