WO2013114401A2

WO2013114401A2 - Flexible wind catching blade for vertical axis wind mill

Info

Publication number: WO2013114401A2
Application number: PCT/IN2013/000047
Authority: WO
Inventors: Prakash Prabhakar Pawar
Original assignee: Prakash Prabhakar Pawar
Priority date: 2012-02-01
Filing date: 2013-01-23
Publication date: 2013-08-08
Also published as: WO2013114401A3

Abstract

The present invention relates to a Flexible wind catching element for vertical axis wind turbine wherein it comprising a plurality of blades; and each blade comprises a frame (8) having a plurality of horizontal blades (2); Each horizontal blade comprises an upper flap (10),a lower flap(14), a flexible element (12) which is connected to back side of said upper flap(10) and said lower flap (14)and a stem(04) in which the flexible elements is fixed; The length of said upper flap, lower flap and stem is such that they are fixed inside the inner side of said frame; height of upper and lower flap is of such when they are wide open they together do not allow any air gap between frame and the horizontal blade. The blades rotate between positions posing a maximum resistance to minimum resistance to maximum resistance, while resistance is generated due to action of wind force on flaps.

Description

FIELD OF THE INVENTION

This invention relates to a Flexible wind catching element/blades for vertical axis wind turbine PRIOR ART:

Due to increase in carbon emission in the environment, it has become necessary to opt for green energy which is now-a-days achieved through many ways like solar, wind, tidal etc. In all these practices pollution free energy is produced but there are some major draw backs to them. One of them is that it is not economically viable. Currently, a lot of technologies are used worldwide to create emission free energy like wind, solar, tidal etc. The newly invented blades will be used in vertical axis wind turbines. In the existing blades used in vertical axis, when these blades or wind catching elements catches the wind and transforms that energy into the rotating motion, the blades opposite to it creates resistance. Because of this, energy is lost by a few percentage. This is one of the drawback. This invention addresses such drawbacks and deficiencies of the available solutions.

In this invention, the blades or the wind catching elements have been designed in such a way, where they catch the maximum amount of wind and transform that energy into the rotating motion and at the same time, the blades of the opposite side reduces the resistance of the wind because of which it will generate more energy from the previous ones. OBJECTIVES OF THE INVENTION

• The objective of the invention is to have maximum energy production in a given air flow rate.

• Also further the objective is to achieve the above mentioned activities with keeping in mind at generating green energy.

• Other objective is to achieve the above mentioned activity by minimizing the losses associated in the energy conversion. • In addition to this the object of the invention is to improve the existing technologies in the same field so that all components used have a longer life and practically it is easier to construct the components and to use these components · Also the_^specific nature of the invention, other features, objects, uses and the advantages thereof will clearly appear from the description below accompanied by the drawings in different views which are not to scale.

STATEMENT OF THE INVENTION

A vertical axis wind mill turbine comprising :

a plurality of blades ;

each blade comprising a frame (8) having a plurality of horizontal blades (2) ; said horizontal blade comprising of :

an upper flap (10),

a lower flap(14),

a flexible element (12) connected to back side of said upper flap(10) and said lower flap (14)

and a stem(04) in which the flexible elements is fixed ;

length of said upper flap, lower flap and stem is such that they are fixed inside the inner side of said frame;

height of upper and lower flap is of such when they are wide open they together do not allow any air gap between frame and the horizontal blade ; the blades rotate between positions posing a maximum resistance to minimum resistance to maximum resistance .while resistance is generated due to action of wind force on flaps .

BRIEF DESCRIPTION OF THE DRAWINGS

For a further understanding of the nature and objects of the present invention, reference should be had to the following detailed description, taken in conjunction with the accompanying drawings, in which like parts are given like reference numerals, FIGURE / DRAWING No 1 IS A FRONT VIEW OF PANEL HAVING 8 HORIZONTAL BLADES.

FIGURE /DRAWING No 2 THREE POSITIONS OF A BLADE IN SECTIONAL VIEW IS SHOWN IN FIRST POSITION is the normal position of the blade where the wind forces are not working.

IN SECOND POSITION is the position of the blade when the wind force is from behind the blade and

IN THIRD POSITION, is the position of the blade when the wind force is from the front of the blade

FIGURE / DRAWING No 3 IS THREE DIMENSIONAL VIEW OF WIND MILL WHERE WIND IS FLOWING ALONG THE DIRECTION OF ONE'S SIGHT FIGURE / DRAWING No 4 IS THREE DIMENSIONAL VIEW OF WIND MILL WHERE WIND IS FLOWING ALONG THE DIRECTION OF ONE'S SIGHT FIGURE / DRAWING No 5 IS THREE DIMENSIONAL VIEW OF WIND MILL WHERE WIND IS FLOWING ALONG THE DIRECTION OF ONE'S SIGHT FIGURE / DRAWING No 6 IS THREE DIMENSIONAL VIEW OF WIND MILL WHERE WIND IS FLOWING OPPOSITE THE DIRECTION OF ONE'S SIGHT FIGURE / DRAWING No 7 IS THREE DIMENSIONAL VIEW OF WIND MILL WHERE WIND IS FLOWING OPPOSITE THE DIRECTION OF ONE'S SIGHT

FIGURE / DRAWING No 8 IS THREE DIMENSIONAL VIEW OF WIND MILL WHERE WIND IS FLOWING OPPOSITE THE DIRECTION OF ONE'S SIGHT DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS. Referring now to the drawings, wherein like reference numerals designate corresponding or similar elements throughout the several views, an exemplary VERTICAL AXIS WIND TURBINE BLADE according to the present invention as depicted in figure2 In particular can be referred.

Various parts of a blade are tabulated as:

The invention relates particularly to a blade which is used in vertical axis wind mill .

The invention relates to a vertical axis wind mill turbine comprising a plurality of blades ;

and the each blade comprises a frame (8) having a plurality of horizontal blades (2);

Each horizontal blade comprises an upper flap (10),a lower flap(14), a flexible element ( 2) which is connected to back side of said upper flap(10) and said lower flap (14)and a stem(04) in which the flexible elements is fixed ;

The length of said upper flap, lower flap and stem is such that they are fixed inside the inner side of said frame; height of upper and lower flap is of such when they are wide open they together do not allow any air gap between frame and the horizontal blade .

In Figure 1 a frontal view of panel having 8 horizontal blades is shown . Figure 1 is the diagram from the frontal view of the panel that when the stem is shown along the length of each horizontal blade. The stem, the flexible elements and both the flaps are individual parts. It cannot be summed as a single part. The stem has two or more slots in which the flexible element is fixed with the help of screws or with the help of rivets or other welding or glueing material and to the other side of the flexible element is connected to the back of the flaps. The upper and lower flap are not connected to each other. They are connected to the flexible part and this flexible part is connected to the stem.

The size of the flexible element totally depends on the size of the windmill. If the windmill is small, the flaps of the blades will be proportionately smaller and the size and thickness of the flexible element, as per requirement, will be reduced. If the windmill is bigger, The size of the flaps will increase accordingly and at the same time, the size, thickness and also the quantity of the flexible elements fixed will increase. For example, in the drawing in 3 to 8, two flexible elements are shown that are connected to a single flap but it can vary according to the size of the windmill. The flaps are kept open or closed because of action of force of wind on them and as they are constrained to be open or close because of elasticity of flexible element . These elements may be hardened steel plates (12) for flexibility which are fixed to the stem (04), one side to the stem and one side to the blades (flaps) (10). But for flexibility, one can use hard steel, springs, plastic, carbon fiber, glass fiber or many more things suitable because the flexibility is needed without any mechanism or hinges between the blade(flap) and the stem. The invention also gives an advantage over prior art where almost similar or related fields of invention flaps are hinged .While here in these invention the flaps are kept in to position because of flexible element strength i.e its elasticity . Moreover it gives lesser area of resistance as the hinged flap is always connected to a surface , while the elastic elements compress the two flaps simultaneously to a minimum area for resistance his also helps to generate more electricity in same flow rate condition of wind flow, as in the invention the blade which is at 180 degree to the blade posing maximum resistance because of comparatively much lesser area of resistance because of compression of flaps to a position posing minimum resistance is achieved . The blades keep rotating between positions posing a maximum resistance to minimum resistance to maximum resistance .while resistance is generated due to action of wind force on flaps .

In figure 2, In the figure 2, there are three positions of the blades (these drawings are sectional views). In first position the normal position of the blade is shown . In second position, when wind blows from the back of the blades, at this time the blades (flaps) will close because of the force of the wind and in figure 3 blades(flaps) are opening wide when wind blows on the front of the blade(flaps). At this time the blades will open wide because of the force of the wind.

Referring figure 3 , where three dimensional view of wind mill when wind is flowing along the direction of one's sight is shown.

For example as shown in figures 3 to 8 , design with four blade vertical axis wind turbine, is shown at any given time the wind force will work from the front on one blade and the flaps of the blade will be wide open. On the exact opposite side of this blade, the wind force will be from behind the blades because of which the flaps of blades will be narrowed and the other two blades will be at normal position because both of these blades is cutting the wind direction and wind is not applying any force from the back or the front so they will be at normal position.

The blade poses maximum resistance when wind flows in a direction as it strikes the flaps in front while flexible elements are at back , the flexible element holds the flaps to open to a position so that flaps of each horizontal blade join together & do not allow any air gap between frame and the horizontal blade and horizontal blades respectively and said plurality of horizontal blades because of simultaneous wide opening of flaps form a continuous mass and force of the wind against the continuous mass rotates the blade and simultaneously the same wind when flows to a blade in a direction such that it strikes first the back side of flaps i.e the side where flexible elements are kept the flexible element bends upper flap and lower flap inside each horizontal blade to a position such they obstruct minimum wind flow and resulting in to maximum air gap(06) between frame and horizontal blade, and maximum air gap(06) between respective horizontal blades and thus pose minimum resistance to wind flow

The number of blades and their sizes can vary according to the need of the design. The Figure 1 with 8 blades is for reference and understanding as to how they will be attached to the panel, because the flaps are moving parts as design requires big blades, it cannot be however made one single blade of two flaps because the flaps are closing and opening very fast . If the flap size will be bigger, it will not be possible to move so fast as compared to the smaller flaps. So when bigger flaps are needed it is designed smaller multiple blades which are fixed onto one panel (figure 1). The panel size will be varied according to the design. When the width of the panels will increase the flaps and the stems will increase in length and when the height if the panel increases, the number of blades will increase. In figure 1 I have shown 8 blades. It can be more or less as per the design.

In 3 dimensional figure of windmill as given in figure 3 to 8 a better idea of the working of windmill comes . In drawing 3,4,5 wind is blowing from the side one views on the paper . So the extreme left blade or panel of multiple blades is wide open and one can see it is obstructing the flow of the wind which results the windmill to rotate clock wise. Now in the same figure , one can see the extreme right side of the blade are narrowed down and they are allowing the same wind to flow through and creating less resistance. At the same time, middle two blades are neutral because the wind force is not applied on those blades but as the extreme left blade rotates and will take place of the next blade, the flaps will be at neutral position. At that time, the previous blade of the extreme left blade will take the position of the extreme left.

Figure 6 ,7 and 8 is showing when the wind is blowing on the opposite side of the previous side and the flaps will work exactly opposite like the extreme right blades are open and the extreme left are narrowed down and still the wind mill will rotate clockwise only. In the figures 3 to 8, the pillar of the windmill is perpendicular (vertical) to the ground is shown Above this pillar the alternator or the turbine is mounted. The axel of the turbine is vertical to the ground which is why this wind mill is called 'Vertical Axis Wind Turbine'. Moreover an alternator is connected to the axle of vertical axis wind turbine.

To this vertical axis, arms, are connected which holds the blades. Two arms parallel to each other and perpendicular to axis of axle of wind turbine holds two blade which are at 180 degrees to each other . So for a design with two blades there are two arms which extend to both sides of shaft of vertical axis wind turbine and in design as shown in figures 3 to 8 four arms are shown which hold blade. In fact practically all wind mill have more than one blade. Moreover in figure 3 to 8 the panel of horizontal blades is shown in all direction. When one look from the back (in figure 6, 7, 8) the flexible part is shown at the back of the flaps.

As shown in fig 2 position 3 reference numeral (18), when wind flows against the wind catching elements, the blades open wide because of the force. When they open wide, they catch more wind which means more force or thrust and when they start to rotate, they rotate around the axis of the turbine. After they complete half rotation, the same blades create resistance. At this time, these blades close partially because of the wind force as shown in fig 2 position 2 reference numeral (16). For example: if the turbine is with two blades (frames/ panels), one blade will be taking the energy from the wind and transferring it to the main axel and at the same time the opposite side blade will be creating resistance. More wind catching area is good for transferring energy from wind to axel but at the same time more wind catching area means more resistance. In this design for individual blades, the inspiration is derived from coconut leaves. They are designed in such a way that when we need more wind catching area, they open wide automatically without any mechanical aid and when they are at the opposite side of the axel, they close and create less resistance towards wind. That is why according to this design; these blades will help in generating more energy.

While the invention has been illustrated and described in detail in the drawings and foregoing description, the same is to be considered as illustrative and not restrictive in character, it being understood that only the preferred embodiment has been shown and described and that all changes and modifications that come within the scope of the invention are desired to be protected.

Claims

CLAIM :

1. A vertical axis wind mill turbine comprising :

a plurality of blades ;

an upper flap (10),

a lower flap(1 ),

and a stem (04) in which the flexible elements is fixed ;

height of upper and lower flap is of such when they are wide open they together do not allow any air gap between frame and the horizontal blade ; the blades rotate between positions posing a maximum resistance to minimum resistance to maximum resistance ,while resistance is generated due to action of wind force on flaps .

2. A vertical axis wind mill turbine as claimed in claim 1 ,wherein blade poses maximum resistance when wind flows in a direction as it strikes the flaps in front while flexible elements are at back , the flexible element holds the flaps to open to a position so that flaps of each horizontal blade join together & do not allow any air gap between frame and the horizontal blade and horizontal blades respectively and said plurality of horizontal blades because of simultaneous wide opening of flaps form a continuous mass and force of the wind against the continuous mass rotates the blade and simultaneously the same wind when flows to a blade in a direction such that it strikes first the back side of flaps i.e the side where flexible elements are kept the flexible element bends upper flap and lower flap inside each horizontal blade to a position such they obstruct minimum wind flow and resulting in to maximum air gap(06) between frame and horizontal blade, and maximum air gap(06) between respective horizontal blades and thus pose minimum resistance to wind flow.

3. A vertical axis wind mill turbine as claimed in claim 1 , wherein the number of blades is greater than one .

4. A, vertical axis wind mill turbine as claimed in claim 1 , wherein the stem has two or more slots in which the flexible element is fixed with the help of screws or with the help of rivets or other welding or glueing material

5. A , vertical axis wind mill turbine as claimed in claim 3 , wherein the flexible element is selected from hardened steel plates (12), hard steel springs, plastic, carbon fiber, glass fiber etc.

6. A vertical axis wind mill turbine as claimed in claim5,wherein two arms parallel to each other and perpendicular to axis of axle of wind turbine holds two blade which are at 180 degrees to each other .

7. A vertical axis wind mill turbine as claimed in claim 5,wherein an alternator is connected to the axle of vertical axis wind turbine.