The invention relates to the field of electrical generation and more specifically to the use of a wind turbine for generating electricity.
As those skilled in the art are aware, the availability of energy sources such as coal, oil and natural gas are limited which has resulted in escalating costs for such fuels. This rising cost is significant for residential users and even more significant for commercial users such as manufacturers where such costs could mean the difference between continued operation and bankruptcy.
As a result of such rising costs, there have been intensive initiatives to develop alternate energy sources, a sub-group of which includes renewable energy sources which capture their energy from ongoing natural processes such as sunshine, wind, flowing water, biological processes and geothermal heat flows. Renewable energy sources may be used directly or used to create other more convenient forms of energy. An example of direct use would include geothermal, while an example of indirect use would include a wind turbine used to generate electricity.
A wind turbine may be attached to an electrical generator to produce electricity. Wind turbines can be separated into two general types based on the axis (either horizontal or vertical) about which the turbine rotates. With a vertical axis wind turbine (VAWT), the generator is typically placed at the bottom of the tower on which the VAWT is mounted so that the tower doesn't need to support it. As shown in
A solar chimney is an apparatus for harnessing solar energy by convection of heated air. In its simplest form, it consists of a black-painted chimney. During the daytime, solar energy heats the chimney, thereby heating the air within it, resulting in an updraft of air within the chimney. A solar tower incorporates solar collectors placed at the bottom of the chimney to warm air near the collectors. The resulting warm air creates an updraft in the chimney. In one configuration of a solar tower, a wind turbine is placed in the chimney and driven by the rising air. The turbine is connected to a generator, thereby producing electricity for storage or distribution. German Patent DE 198 21 659 entitled “Power Station Using Updraft Flowing Up Tall Chimney”, filed May 14, 1998 and invented by Manfred Fischer describes such a configuration. Referring to
Both the VAWT and solar tower or chimney are capable of adequately producing electricity in their own right, but they are both limited by design. More specifically, the VAWT must have wind in order to operate which restricts its use to specified geographical areas where there is consistent wind. The solar chimney relies on sunlight to produce sufficient updraft to drive the wind turbine so its use is also geographically limited. A wind turbine which could operate in a wide variety of climates would be ideal.
The present invention seeks to overcome the deficiencies of the prior art by providing a vertical axis wind turbine mounted on the upper portion of a chimney. Rotor blades are disposed on the outside of the chimney and the mechanical energy produced by the rotating rotor blades is transferred to a generator by means of a short drive shaft. More specifically, if an alternator (i.e. and alternating current (AC) generator) is used, the drive shaft is used to drive the AC field windings or rotor which rotates within the generator armature windings or stator. Alternately, the wind turbine and generator are integrated. The rotor blades are coupled directly to a rotating, current inducing set of permanent magnets or rotor for rotation about a stationary, current generating stator.
Certain exemplary embodiments provide a wind turbine mountable at or near an upper portion of a chimney, or forming an integral component of an upper portion of the chimney, the wind and updraft turbine comprising: a blade mounting rotor hub coupled to a collar rotatable about the upper portion of the chimney, about an axis at least substantially in line with a main axis of the chimney; and at least two wind-engaging rotor blades extending outwardly from the rotatable blade mounting rotor hub, wherein each of the at least two wind-engaging blades are movable upon application thereto of an air movement about the chimney selected from at least one of the group consisting of: (i) an updraft about an interior of the chimney; (ii) an updraft about an exterior of the chimney; and (iii) a prevailing wind. Preferably, a generator is operably linked to the rotatable collar for converting mechanical energy produced by the rotatable collar into electrical energy.
Certain other exemplary embodiments may provide a wind and updraft turbine mountable at or near an upper portion of a chimney, or forming an integral component of an upper portion of the chimney, the wind and updraft turbine comprising: a current inducing rotor comprising a current inducing set of permanent magnets rotatable about the upper portion of the chimney, about an axis at least substantially in line with a main axis of the chimney; a stationary, current generating stator comprising at least one wound coil about which the rotor rotates, wherein the rotor generates a magnetic field which passes in close proximity to the at least one wound coil; and at least two wind-engaging rotor blades extending outwardly from an outer casing associated with the rotor, wherein each of the at least two wind-engaging blades are movable upon application thereto of an air movement about the chimney selected from at least one of the group consisting of: (i) an updraft about an interior of the chimney; (ii) an updraft about an exterior of the chimney; and (iii) a prevailing wind.
Still certain other exemplary embodiments may provide a wind and updraft turbine mountable at or near an upper portion of a cylindrical pole, the wind and updraft turbine comprising: a current inducing rotor comprising a current inducing set of permanent magnets rotatable about the upper portion of the cylindrical pole, about an axis at least substantially in line with a main axis of the cylindrical pole; a stationary, current generating stator comprising at least one wound coil about which the current inducing rotor rotates, wherein the current inducing rotor generates a magnetic field which passes in close proximity to the at least one wound coil; and at least two wind-engaging rotor blades extending vertically from an outer casing associated with the current inducing rotor, wherein each of the at least two wind-engaging blades are movable upon application thereto of a prevailing wind.
The advantages of the invention are now readily apparent. The wind turbine of the present invention can generate electricity using the updraft associated with the chimney or from the prevailing wind. The present invention makes use of existing structures (e.g. smoke stacks on factories or refineries, natural gas well burn off stacks, apartment buildings chimneys, telephone poles, etc,) allowing wind turbine owners to be at least partially self-sufficient for their supply of electricity. Additionally, the need for power distribution lines running for several miles from generator stations to factories or residences is eliminated.
The invention will now be described in relation to the following drawings in which:
a) depicts an exploded view of the stack of
b) depicts a top view of the second embodiment of
c) depicts the second embodiment of
d) depicts in greater detail the stator of the embodiments of
e) depicts in greater detail the rotor of the embodiments of
f) depicts in greater detail the rotor blades of the embodiment of
a) to 8(c) depict a variation of the embodiment of
d) depicts a variation of the embodiment of
a) to 9(l) depict various blade configurations which may be used in the wind turbine of the present invention;
Serpentine drive belt 120 is driven by wind-engaging rotor blades 130 which capture the updraft or wind and transfer its power to rotor hub 140. Rotor hub 140 is attached to collar 150 which is rotatably mounted at or near the discharge end of smoke stack 80. Serpentine drive belt 120 is mechanically coupled to collar 150 extending around the circumference of smoke stack 80. It should be appreciated that rotor blades 130 and rotor hub 140 to which they are attached, are often referred to in the industry as the rotor. This is not to be confused with the rotor integral to generator 100 which will be discussed in more detail below.
As understood by those in the art, electrical generator 100 is a device that produces electrical energy from a mechanical energy source. An alternator is a generator that converts mechanical energy to alternating electrical current. When the magnetic field around a conductor changes, current or energy is induced in the conductor. Referring to
a) and 7(b) depict a second embodiment of the present invention. In this configuration, generator 100 is integrated within the wind turbine at the top of smoke stack or chimney 80. In this embodiment, rotor blades 130 are coupled directly to a rotating, current inducing set of permanent magnets or rotor 220 for rotation about a stationary, current generating stator 230. The outer casing of rotor 220 includes bearings (not shown) positioned at the top and bottom which allow rotor 220 to rotate smoothly about stator 230. Similar to a traditional generator, the permanent magnets produce a magnetic field. However, rotor 220 rotates around stator 230. When the magnetic field of rotor 220 cuts through the conductors of stator 230, a voltage is induced in the conductors. Stator 230 may be wound for single phase or three phase alternating current generation as is well known in the art. The key advantage of this configuration is that the need for a driveshaft to link collar 150 to generator 100 is avoided. The number of moving parts is thereby reduced which serves to lower maintenance costs and minimize downtime of the wind turbine.
d) and 7(e) depict in greater detail the rotor and stator of the embodiments shown in
a) to 8(c) depict a variation of the embodiment of
As depicted in
As those in the art will appreciate, there are two basic types of airfoils (i.e. rotor blades 130) used in wind turbines: a lifting type; and a drag type. With the drag style airfoil rotor blades 130 are generally a flat plate which the wind hits and causes to rotate. This type of design is great for very low wind areas and will develop a lot of torque to perform an operation (such as turning a shaft connected to generator 100). However, in medium to higher winds, their capabilities to produce energy are limited. The lifting style airfoil is generally used in most modern horizontal axis wind turbines (HAWTs) and has the general shape of an airplane wing to facilitate lift in accordance with well understood aerodynamic principles. A properly designed lifting airfoil is capable of converting significantly more power in medium and higher winds. Additionally, only a few blades (i.e. three) are used to achieve the greatest efficiency. As can be seen from
In addition to wind directly striking rotor blades 130, rotor blades 130 are designed to take advantage of the updraft created by: (a) hot emissions from smoke stack 80; (b) heating of the air adjacent the exterior surface of smoke stack 80 by conduction of internal heat in smoke stack 80; (c) heating of air within smoke stack 80 and adjacent the exterior surface of smoke stack 80 by solar radiation; and (d) wind hitting and being forced upwards along the exterior of smoke stack 80 i.e. an updraft. With respect to (c), it should be appreciated that even when smoke stack 80 is not in operation discharging waste emissions, it can nonetheless be used to create an updraft. Similar to the operation of the solar chimney discussed in the background section, if smoke stack 80 is painted a dark colour, the sun will heat the air inside smoke stack 80 and the air along the exterior of smoke stack 80, causing it to rise and create an updraft.
The diameter of smoke stack 80 can vary from 1 inch to 25 feet, while the height of smoke stack 80 can vary from 10 feet to 1000 feet. It should also be appreciated that the present invention can be adapted for both industrial and residential applications i.e. fitted on any stack where an updraft can be created to drive rotor blades 130. In the present invention, the shapes and angles of rotor blades 130 will vary depending on the configuration of smoke stack 80. For example, if smoke stack 80 is located in an area where there are several stacks, there will be more updraft and less prevailing wind, while a single smoke stack 80 will have less updraft and more prevailing wind. In either situation, the updraft and/or prevailing wind can be used to generate power. In the event that there is no prevailing wind, the updraft can power the wind turbine of the present invention independently. Alternately, if the factory is not in operation such that there is no discharge from smoke stack 80, solar heating of smoke stack 80 and/or the prevailing wind can independently drive the wind turbine.
As can be seen in
As shown in
Although the present invention has been fully described by way of the examples with reference to the accompanying drawings, it is to be noted that various changes and modifications will be apparent to those skilled in the art. Therefore, unless such changes and modifications otherwise depart from the spirit and scope of the present invention, they should be construed as being included therein. For example, as highlighted above in relation to
The wind turbine of the present invention can generate electricity using the updraft associated with a chimney or from the prevailing wind. The present invention makes use of existing structures (e.g. smoke stacks on factories or refineries, natural gas well burn off stacks, apartment buildings chimneys, telephone poles, etc,) allowing wind turbine owners to be at least partially self-sufficient for their supply of electricity.
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/CA2007/000665 | 4/20/2007 | WO | 00 | 2/11/2009 |
Number | Date | Country | |
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60794094 | Apr 2006 | US | |
60869860 | Dec 2006 | US |