(Patents applied P/1/19979) - The Inspiration of Lateral axis wind turbine
Impulse
tubine for wind power generation
Inspired by lateral axis wind turbine the author
is able to design and build an amazing vertical axis wind turbine
that can deliver higher power than horizontal axis wind power generator.
The wind turbine with a contour tracer is having
turbine blades spinning around their own axis while orbiting around
the central shaft vertically positioned on a horizontal rigid basement.
A pair of hubs is mounted on bearings to the central shaft, positioned
apart, at top and bottom of the said central shaft. A symmetrically
positioned plurality of extended arms extended outwards around the
central shaft, forming a rotor framework. Each turbine blade is
integrated with an extension of shaft projected down words supported
on pivots located on said extended arms of the said rotor framework.
A horizontal platform is having over the basement and it is drivable
on bearings fitted to central shaft in order to adjust its orientation
to face the turbine blades along desired direction.
Down side of each turbine shaft is fitted with a crank arm, providing
leverage to hold a roller to paddle along the track set on a horizontal
platform disposed above the basement.
In operation, working cycle of each turbine blade is having a power
stroke and a return stroke. During power stroke turbine blades are
turned perpendicular to the direction of streaming wind whereas
during the return stroke turbine blades are turned along the direction
of wind. Concurrently, the turbine shafts are rotating about the
central shaft, while the turbine blades turning around the own axis.
The turbine blade direction is controlled by the contour traced
by the roller during power stroke.
In operation, the said roller engage with the contour track and
paddle between two guide walls of contour track, thereby turning
the surface of the turbine blade perpendicular to wind direction
and maintaining its direction during the first half circle of movement
of the turbine blade. When the turbine blade moves to the extreme
end, the contour track releases engagement of the roller thereby
allows the turbine blade move freely. Then the turbine blade turns
along streaming wind direction and produce minimum air resistance
during its return stroke until it propel back on the other way round
to the starting position. Thus another cycle continues by the roller
engagement with the contour track.
The turning movement of the rotor geared to electricity power generator
to produce usable electricity.
Further, a break system and controls are accompanied to stop or
reduce the rotational speed of the rotor and turbine blades.
The crank arm is designed in such a manner that the rear side of
the rank arm is extended backwards so that a peg positioned on the
bracket of the rotatable secondary platform, be impelled on the
rear extension of the crank arm in order to turn the turbine on
desired direction at the end of power stroke.For best performance
number of turbine blades should be two or three.
This wind turbine is low cost high efficient easy to assemble and
build product. Its blades cover much larger area than a circular
profile of the space of streaming wind. Power generator and control
equipment are installed on ground level and reduces maintenance
cost procedures. It can build to greater height.
As a summary this is a vertical axis wind turbine,
absent from control tracks overhead of the wind tower, that comprises
a central shaft mounted vertically on a rigid basement; with a pair
of hubs secured on bearings to said central shaft; while aforesaid
two hubs having a symmetrically located plurality of arms extended
radially outwards, forming a rotor frame; with a plurality of turbine
blades fitted on vertically held turbine shafts and pivoted on bearings
between each pair said extended arms to orbit around central shaft;
characterized by each aforesaid turbine shafts connect rigidly with
a crank lever arm on each at the bottom end of said turbine shafts;
while rollers to be secured at the end of each crank arm, so that
the said each roller dwell the contour track formed on a horizontal
table during power stroke, thereby the direction of each turbine
blade to be controlled by the engagement of rollers in the contour
track formed on the said horizontal table, while having means for
gear arrangement to connect said bottom hub to an electricity generator
thereby the rotary motion of the bottom hub be able to transfer
power as consumable electricity, during operation, when the streaming
wind impel on turbine blades, in order to undergo a change of orientation
of said wind turbine blade, during each cycle of rotation around
central shaft, and coming back to their original position after
each revolution so that the motion of the rotor be able to take
up by electricity generator.
Impulse turbines change the
direction of flow of a fluid. In reaction turbines air flow pass
through the moving blades. Betz law applies for the wind flow that
passes through the turbine. This wind terbine is an impulse turbine.
Power generating ability compared to horzontal axis wind turbine
is analysed here
The lateral axis wind turbine
(Sri Lanka Patent 17981)
The lateral axis wind turbine delivers breakthrough
clean energy technology
It differ from horizontal axis wind turbine and vertical axis
wind turbine for having its central shaft mounted horizontally on
upright supports while turbine blades spin on extended arms around
the central shaft.
Why we claim lateral axis wind turbine having higher efficiency
compared to vertical axis wind turbine:
It sweeps rectangular area of space of the wind blowing profile,
covering much larger space than a circular profile.
Lateral axis wind turbine deliver wind force along the direction
of the blowing wind, while vertical axis wind turbine receive
a faction of the force of wind power.
How lateral axis wind turbine works:
The turbine blades orbit in an epicyclical path
around central shaft, akin to Ferris wheel. If the horizontal
axis wind turbine having its rotor radius 5 meters It's sweeps
an area of 5x5x3.14159 Sq.meters.( 78.54 Sq M)
When we install a lateral axis wind turbine covering
the same space the swept area is 10x10. (100 Sq.M)
Lateral axis wind turbine does not generate sounds
due to aerodynamic movements of blades through air. This wind
turbine stands like a tree on ground causing movement of blades
only along the wind direction. So that there is no possibility
of birds and bats getting stuck with turbine blades causing death.
The wind turbine comprises of a pair of
oppositely placed hubs in combination of plurality of extended
radial arms symmetrically projected out wards and fitted on bearings
to the central shaft. The turbine blades are pivoted between each
extended pair of arms and are having the freedom to swing around
their own axes and around the common axis of central shaft.
The central shaft comprises of a cam profile
over which lever arms of turbine blades could engage during its
working cycle. In operation, the streaming wind, forces the blade
along the direction of wind while the extended lever arm turn
towards the cam profile fitted around the central shaft. During
power stroke the cam profile prevents the blade swing any further,
by giving leverage to the turbine blade to force pivot axis of
the blade turn forward along with the wind direction. Lever arms
terminate engagement with cam profile during idle stroke and revolve
around central axis and come back to initial position during next
phase of the working cycle.
During the period from bottom until the axis
turn 90 degrees the turbine blade glide against the wind like
airplane and provide lift on pivoted axis until the liver arms
engage with the cam profile to provide leverage by the wind pressure.
Passive yaw control is archived by fixing
flat plates, on the surface of rotating radial arms perpendicular
to main shaft axis. Alternatively orienting the turbine blades
in the wind direction is achieved by motor controlling the vertical
shaft axis which is mounted rotatable on the towering structure
of the wind mill.
Advantageously, the turbine blades are designed
in such a manner that the airfoil creates a lift during its upward
movements. Number of blades can vary from two to a higher value.
The turbine design has low center of gravity and easy to assemble.
This is one of the most productive wind turbines in its price
range. With urban roof mounted design it is an energy saver in
domestic applications. These wind turbine blades are suitable
for applying as dynamic advertisement display boards also.
The illustration shown below is the behavior of ONE
TURBINR BALADE during a complete cycle
This Wind Turbine design could potentially generate 20
Megawatts in commercial scale. It can turn by rainfall and snowfall
as well.
This design doesn't involve complicated
manufacture. Therefore it can fabricate with scraps and locally
available materials.
Turbine control is used for efficient performance
and for low maintenance costs. Further it helps safe operation,
structural stability and optimum output. The yaw system can align
the wind turbine in parallel with wind direction.
Different control strategies may be applied for yaw control.
A passive yaw control systems is applied using the wind force
to turn the rotor towards the wind. An active yaw system also
could be applied to a commercial scale large wind turbines.
According to their rotor layout, presently
known wind turbines are categorized into horizontal-axis wind
turbines (HAWT) and vertical-axis wind turbines (VAWT).
The rotor of a HAWT is horizontal and must point to the wind.
The rotating plane of HAWT blades is perpendicular to the wind
direction during operation. The turbine blades are radial and
their number is varies 2 to a higher value. Most efficient designs
use 2 or 3 turbine blades. Yaw control device has to accompany
HAWT.
The shaft of a VAWT is perpendicular to the ground and the wind
direction. VAWT accepts the wind from all horizontal directions;
there is no need of a yaw control devices.
Although both designs require a large area acquiring large ground
space amount of energy that can utilize is small. This is because
the exposed turbine blade area according to design conditions
has to limit to a small fraction of the swept area.
This problem has overcome by the present invention by turning
the blades in a lateral direction of the blowing wind, while leaving
the blades to face full force of the wind.
This wind turbine manufacture doesn't involve
complicate designs for the blades, making it simple to the constructuctor.
we can use locally availble materials and lightness of the selected
material are not considered.
Main components of the wind turbine:
1. Main shaft; 2. Turbine blades; 3. Turnable mount; 4.turbine mast;
5. control bar; 6. Yaw control; 7. Yaw arm; 8.pivot arm; 9. Yaw control;
10. Gearing; 11. power generator; 12. casing for motors; 13. Power
transfer gear; 15. extension tips; 16 Cam Contour profile; 17.hubs
on bearings; 18. Nacelle
At present we supply and install wind turbines on roof slabs
at height not less than 30 ft. (10 Meters) provided that the surrounding
free from obstacles for wind for 100 ft. radius. The price is us$
1000+ delivery charges. It is capable of generating average 15 Amp
at 12 volts. This wind turbine will deliver uninterrupted power supply
of 1/4 kW when it is coupled with an inverter