1. Field of the Invention
This invention relates to wind-driven turbine. A wind turbine is a device that converts the force of the wind into rotary motion. This rotary motion is then used for direct mechanical energy or converted into another form of energy like electricity or heat.
2. General Background
For many years man has been using wind power, a renewable non-polluting source of energy. This source of energy has been used in the past in two major forms of energy extraction devices. One, being the vertical axis wind turbine and the other, the horizontal axis wind turbine.
The vertical axis wind turbines have a main rotating shaft that is perpendicular to the surface of the earth and tend to employ turbines with more surface area. This larger surface area can be a bonus as they can catch more of the wind's forces. However, some reverse friction occurs on the back side of the turbine on the return path. Many inventors have created clever devices that reduce this back side friction but these devices are complicated and might have tendencies to malfunction or produce extra noise.
The horizontal axis wind turbines have a main rotating shaft that is parallel to the surface of the earth and usually are placed on top of a tall vertical structure. These tall vertical structures can be expensive and the cost usually goes up incrementally with height. This is further complicated by the fact that most have to be serviced while remaining atop of these tall structures. Moreover, installation of these wind turbines requires a very large crane and many personnel to complete the installation. Previously, most horizontal axis wind turbines required a large tail to keep the turbine facing into the wind. This is because the turbine is upstream of the pivot point atop of the tower. In the present invention, the tail is totally unnecessary because the turbine is downstream of the pivot point and automatically faces into the wind.
Other problems commonly known with previous designs of horizontal axis wind turbines include poor efficiencies, and little to no power is produced at wind speeds below ten miles per hour. Some have recognized that funneling the wind could solve these problems. But previous attempts of mounting a wind funnel on a horizontal axis wind turbine included very complicated assemblies. These assemblies had to be close coupled to the turbine and had to simultaneously turn with the turbine into the wind. In this present invention, the funnel is part of the turbine. The funnel section of the turbine increases the force of the wind on the turbine blades on the inside of the conical frustum, where it crosses the turbine blades to the outside of the turbine. This outside surface of the conical frustum creates its own low pressure. This low pressure adds to the lift of the turbine blades by increasing the velocity of the fluid crossing the turbine blades. The net effect is a very efficient wind turbine that can operate in lower wind conditions. As well, it is robust and can be manufactured economically.
Referring to
The members of the turbine 12 have specific purposes. The funnel 8 collects the wind and increases the pressure of the air as it funnels it down and directs it to the turbine blades 9. Since the widest diameter of the funnel automatically faces into the wind, it will be perpendicular to the laminar flow of the wind. This means that the air that passes outside the lip of the funnel will be disturbed and become turbulent as it passes the widest section of the funnel 8 mouth. This action creates a low pressure on the outside of the conical frustum turbine. This low pressure helps to increase the velocity of the fluid passing through a turbine blade opening 15. This increases the usable rotational energy produced by the turbine 12.
The surface area of the funnel 8 mouth of the turbine 12 and the total surface area of the turbine blade openings 15 have an important ratio. Hereafter, this ratio will be referred to in terms of surface area of funnel mouth to total surface area of the turbine blade openings 15 where, when the funnel mouth has twice the surface area it would be called 2:1. When designing a wind turbine system for use in lower wind conditions, this ratio would range between 2:1 and 10:1. As this ratio increases, the air pressure on the inside of the turbine increases, and the usable energy at low wind speeds also increases. Also, as the pressure increases on the inside of the turbine 12, the core of the turbine 12 starts to become saturated to a point where it opposes the wind. Near this point of saturation, the turbine 12 is turning near top speed, and any increase in wind speed would increase the perpendicular force against the turbine 12. This increased force against the turbine 12 would translate into force against the other member of the system. Therefore, building a turbine with a higher ratio than 5:1 could become cost-prohibitive mainly because some of the members of the system would have to be fortified to withstand high wind conditions. Under circumstances where a very tall vertical support is used or where damaging winds are common, a ratio of less than 2:1 is preferred.
The turbine blades 9 partially cover the turbine blade openings 15 and are angled optimally to give the maximum rotational torque when the air passes through the turbine blade opening. These angled turbine blades 9 may also be twisted along their length for added torque. The frustum 10 is a closed surface and connects the downwind hub 7 to the turbine blades 9.
Yet another embodiment of this present invention is displayed in
In yet another embodiment of this present invention, funnel support blades 14 shown in
In yet another embodiment of this present invention, the vertical support 1 in
In order to raise the upper vertical support 24, a hydraulic cylinder 21 can be used. This hydraulic cylinder 21 would normally be removed after lifting the upper vertical support 24 to the energy producing position and the upper vertical support 24 would be affixed by heavy mechanical means. But where an automated system is preferred, the hydraulic cylinder 21 might stay in place. Then the upper vertical support 24 could be lower to the maintenance position by automatic means. This would be advantageous when extremely high winds occur. In the maintenance position, the turbine 12 is no longer perpendicular to the wind so the rotation of the turbine 12 decreases.
In yet another embodiment of this present invention, the vertical support 1 in
According to one embodiment of the present invention, there is a wind energy recovery system. This self-funneling conical frustum wind turbine converts the power of the wind into a clean renewable source of energy. This energy originates in the laminar flow of the wind, and is converted by the self-funneling conical frustum wind turbine. This is done when the leading edge of the integral funnel captures the wind and guides it into the core of the turbine. This raises the pressure in the core of the turbine and lowers the pressure of the air surrounding the turbine. This pressure differential causes the air to rapidly flow through the openings of the turbine. This fast moving air passes across angled blades and that gives the turbine rotational spin. The rotational spin transfers its energy to a central shaft that supports the turbine. This rotating central shaft now transfers the energy to an energy conversion device. This energy conversion device could be an electrical generator, a fluid compressor or any other energy conversion device capable of converting rotary energy. Normally, this energy conversion device can be mounted atop of a bearing mechanism. This bearing mechanism normally has a solid surface on the top that can rotate independently from the bottom section of the bearing mechanism. The top surface is where a means for supporting the shaft and allowing its rotation are affixed. This supporting mechanism can be a set of bearings, a gearbox or an energy conversion device. The bottom section of the bearing mechanism is connected to the support. According to one embodiment of this present invention, this support can be a fixed vertical support that anchors to the earth. But other embodiments may include a rooftop support or a retractable support.