Abstract:
A wind power generation system using the Bernoulli principle having an elongated tube, wind entry and exit openings on opposite ends of a main body of the tube, a central wind passing section of the tube having a smaller diameter than that of the wind entry and exit openings between the opposite ends, support struts spanning the wind entry and exit openings, and left and right power generators arranged centrally of the support struts, with the generators being rotated simultaneously on a single rotation shaft axle. Plural wind turbines are provided left-right symmetrically on the rotation shaft axle, and transverse rotation bearings are provided on the lower and upper part of the wind passing tube, so the tube can pivot into the wind via vanes.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     Embodiments of the invention relate to a symmetrical dual-structured wind power generation system, and more particularly, to a symmetrical dual-structured wind power generation system through which wind power generation efficiency is increased doubly and further electric power is generated even in a light wind. 
     2. Description of the Related Art 
     Generally, Bernoulli principle technology has been adopted for a wind power generation using wind tubes in the prior art. The configuration disclosed as a prior wind power generation system in Korean Patent Registration No. 20-0271770 comprises a rotating propeller and a generator inside a venturi tube, which is considered to be simple, and is shown in  FIG. 11  of the drawings of this disclosure. Under this configuration the generator arranged inside a venturi tube interrupts wind flow but sometimes the wind becomes reversed, causing a decrease in efficiency. In particular, the prior art power generation system can be operated in a wind moving in a single direction. However, wind does not flow typically in one direction and varies in its direction, that is, wind flows from seashore to land during daytime and in an opposite direction during night time, causing wind power generation efficiency to decrease. Meanwhile, since the weight of the prior wind power generator is heavy and further a rotating part thereof which is operated depending on a wind direction is arranged on a lower support part of a power motor, rotational efficiency is decreased dramatically depending on a wind direction variation. Further, only one power generation system is placed on one support column, causing the installment cost to be high. In particular, under this configuration wind has to be strong enough for power generation and thus its use is limited to high mountains and seashores, where strong wind can be expected. 
     SUMMARY OF THE INVENTION 
     Embodiments of the invention are proposed to solve the aforementioned drawbacks of the prior art, and one object of the invention is to provide a wind power generation system which can be operated in light wind in and rotated smoothly depending on wind direction variation, improving power generation efficiency doubly, as compared with the prior art wind power generation system. 
     Another object of the present invention is to provide a wind power generation system where several of the generator systems can be arranged on one support column and further can be placed in various locations such as a tree in a forest, a street light in a city, a wall face of a building, such locations not being limiting to places where strong wind is expected, thereby improving wind power generation efficiency. 
     The wind power generation system according to the present invention includes a main body of a Bernoulli tube form, a wind entry and exit opening arranged left-right symmetrically on the main body tube, two power generators arranged in the central part of the wind entry and exit openings, respectively, wherein two power generators rotate about a common rotation shaft axle. Turbine blades or propellers are arranged on the left, right, and possibly middle part of the rotation shaft axle, and the rotation axle is thereby rotated by wind energy to generate electric power. 
     According to one embodiment of the present invention, a transverse rotation arrangement for the tube body is arranged doubly on the lower and upper (left or right) part of a middle area of the left and right sides of the main body and a double support rod is provided connected to the main body so the body can be rotated about a transverse axis with light wind. 
     Meanwhile, according to another embodiment of the invention, since the power generator is arranged in the middle part of the wind entry and exit, respectively, the kinetic energy of the wind may be used maximally. The diameters of the wind entry and exit are also made large and the central wind passing tube diameter is smaller, so that the speed of wind flowing through the wind passing tube is increased due to the Bernoulli effect, thereby improving power generation efficiency. Furthermore, the left and right generators are rotated simultaneously by the double rotation turbine blades by even a light wind. In addition, two generators are operated in a single wind power generation system, doubly increasing power generation efficiency. The lower and upper (or left and right) transverse rotation axle are provided left-right symmetrically on the middle of the central tube and thus the main body can be rotated by light wind, increasing power generation efficiency more than 50%. 
     According to another embodiment of the wind power generation system of the present invention, several generator systems may be arranged on one support column so that a multiple power generation system will occupy only a small space, saving cost. The system may be located anywhere wind occurs, and is not limited to a particular location. 
     It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of embodiments of the invention as claimed. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  shows schematically main elements of a wind power generation system according an embodiment of the invention. 
         FIG. 2  shows schematically an operation of a wind power generation system according to an embodiment of the invention. 
         FIG. 3  is a front view of a configuration shown in  FIG. 1 . 
         FIG. 4  shows schematically a ring and insect net assembled for the wind power generation system according to an embodiment of the invention. 
         FIG. 5  shows schematically the wind power generation system formed to be portable according to an embodiment of the invention. 
         FIG. 6  shows schematically the wind power generation system connected to a base or plate structure according to an embodiment of the invention. 
         FIG. 7  shows schematically the wind power generation system connected to a street light according to an embodiment of the invention. 
         FIG. 8  shows schematically the wind power generation system connected to a tree according to an embodiment of the invention. 
         FIG. 9  shows schematically the wind power generation system connected to a wall face or a building according to an embodiment of the invention. 
         FIG. 10  shows schematically the wind power generation system arranged in plural left-right rows and up-down columns (i.e., a grid) according to an embodiment of the invention. 
         FIG. 11  shows a prior art wind power generator. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The preferred embodiments of a wind power generation system will be described in detail with reference to the accompanying drawings. However, it has to be understood that the invention is not limited to the preferred embodiments described herein. 
       FIG. 1  shows schematically the wind power generation system according to an embodiment of the invention. As shown in  FIG. 1 , a main body  1  of the system is left-right symmetrically formed Bernoulli tube. That is, a wind entry opening  5   a  is placed on left side and a wind exit  5   b  is placed on a right side of the main body  1 , which are symmetrical as shown, and further a central wind passing tube  5   c  is arranged in a middle part of the main body  5 . Here, the diameter of the wind passing tube may be less than a half of those of the wind entry opening  5   a  and the wind exit opening  5   b , consistent with obtaining a Bernoulli tube effect. 
     As shown in  FIG. 1 , a left support strut  3   a  is provided vertically (or horizontally) in the wind entry opening  5   a  of the left side of the main body  1  and further a left electric generator  4   a  is connected to the left support shaft axle  2  supported centrally by strut  3   a . Additionally, a right support strut  3   b  is provided vertically or horizontally in the middle part of the wind exit opening  5   b  and further a right generator  4   b  is connected to the right side of axle shaft  2  supported by strut  3   b . Here, a single rotation axle  2  is provided between and connected to the left generator  4   a  and the right generator  4   b  and the left generator and right generator are operated by the rotation shaft axle  2 . A plurality of turbine blades  6   a ,  6   b  for converting axially moving wind flowing through the tube  5   c  to rotation force are provided in axially spaced relationship on the rotation shaft axle  2 , and there may be provided a plurality of 2-4 elements on the middle part of the wind passing tube  5   c . That is, in summary, the wind entry opening  5   a , the left support strut  3   a , the left generator  4   a  and the turbine  6   a  are provided in sequence from the left side of the main body  1  towards the right side symmetrically in a Bernoulli tube form and further the wind exit opening  5   b , the right support strut  3   b , the right generator  4   b  and the turbine  6   b  are provided on the right side of the main body  1 , so that the left elements and the right elements are connected along one rotation shaft axle  2 . The turbine  6  provided on the rotation shaft axle  2  may be placed on left and right sides or a middle part of the wind passing tube  5   c . However, in consideration of variable wind direction, the turbine blades  6  may be configured left-right symmetrically in order to generate power even in case of reverse wind flow. 
       FIG. 3  shows schematically a front face of the wind power generator according to the present invention, the views of the wind entry opening  5   a  or the wind exit opening  5   b  being symmetrical with each other. As shown in  FIG. 1  (but not visible in  FIG. 3 ), upper and lower rotation or bearing rings  8   a ,  8   b  are provided on the middle part of the main body  1  and further upper and lower support rods  9   a ,  9   b  are connected to the upper and lower rotation rings  8   a ,  8   b , respectively. Alternatively, as shown in  FIG. 4 , a separate support ring  12  is connected to the rotation rings  8   a ,  8   b  by support rods and further the support ring  12  on its inner side is connected to the main body  1  in a vertical or horizontal direction by the support rods, with upper and lower support rods  9   a ,  9   b  being connected to the outside of the separate ring  12  (not illustrated in  FIG. 4 ) by rotation rings. 
     In operation of the wind power generator according to the present invention, as shown in  FIG. 2 , it is well known that wind entering through the wind entry opening  5   a  will be accelerated in the wind passing tube  5   c  which has smaller diameter than the wind entry opening. The accelerated wind causes the left turbine  6   a  to be rotated and passes through the wind passing tube  5   c  and then causes the right turbine  6   b  to be rotated. At this time the rotation axis  2  is rotated through the rotation of the left and right turbines  6   a ,  6   b  and thus the left and right generators  4   a ,  4   b  are operated to generate electrical power. 
     According to the present invention, an advantageous effect is obtained that solves drawbacks of the prior art (see  FIG. 11 ), where wind impacting against blades and generator provided in the wind passing tube  5   c  interrupts or impedes wind flow and sometimes causes reverse-flow, thereby decreasing power generation efficiency. That is, according to one embodiment of the present invention, the left and right generators  4   a ,  4   b  are provided on the central part of the wind entry and exit openings  5   a ,  5   b  so that wind resistance is decreased and further double turbines are provided on one rotation shaft axle inside the wind passing tube  5   c  so that power generation efficiency is increased. Accordingly, the left and right generators  4   a ,  4   b  are operated doubly efficiently through the turbines  6   a ,  6   b , compared to the prior art wind power system. In particular, even if wind flows in through the wind exit opening  5   b , the same power as in case of the wind entry at wind entry opening  5   a  is generated. That is, even when wind direction is changed at 180 degree, power is generated with the same efficiency. 
     Meanwhile, a wind direction key or vane  13  is provided on the respective wind entry opening  5   a  and wind exit opening  5   b  so that the main body  1  is rotated smoothly in the manner of a weathervane even with a light wind flowing. Here, the wind direction vane  13  may be provided either on outside or on inside of the main body  1 , as shown in  FIG. 4 . When the wind direction vane  13  is provided symmetrically on left and right ends of the main body, power generation efficiency is increased dramatically in case of wind direction being reversed, especially in a city street, or at morning or evening times. 
     The main body  1  configured left-right symmetrically is connected to the left and right rotation bearing rings  8   a ,  8   b  and the upper and lower support rods  9   a ,  9   b , so friction force is decreased doubly at the upper side and lower sides, and thus even in case of light wind the main body may be rotated depending on wind direction, increasing power generation efficiency by 50%. 
     Meanwhile, the wind power generation system according to the present invention may be provided with a tripod  10 , as shown in  FIG. 5 , and it may generate power outdoors as a portable power generation system. Furthermore, as shown in  FIG. 6 , several wind power generation systems according to the present invention may be provided on a lower support rod  14  of a solar power generation system  14   a . In addition, as shown in  FIG. 7 , the wind power generation system according to the present invention may be provided on a street light  15  or a traffic light and further a support rod in the form of a gate (not shown) may be provided on a road and the gate may be provided at a regular intervals on the road depending on wind strength and several wind power generation systems may be arranged in parallel on an upper part of the gate and thus the wind power generation system may be provided on whole country road network. 
     As shown in  FIG. 8 , the wind power generation system according to the present invention may be provided on a tree  16  in a forest in mountains and further may be provided a wall face  17 , as shown in  FIG. 9 , and the wind power generation system may be provided on a business building, office building, advertisement board, apartment wall face, school building, etc. Accordingly, separate power generation systems for each building can be provided. When the wind power generation system is provided on a support rod or a tree in a forest, or a street light on a road, small insects, leaves, etc. may be ingested into the interior of the system and thus the wind passing tube  5   c  may be contaminated with such materials. In order to avoid this contamination, as shown in  FIG. 4 , an insect net screen  11  may be provided on the wind entry and exit openings  5   a ,  5   b  and thus contamination inside the wind passing tube  5   c  and around the turbines such as insects or other impurities, may be avoided when the wind power generation system is located in a forest, downtown or on a street light. 
     As shown in  FIG. 10 , a frame main body  1   a  may be provided and when  10  units of the wind power generation system each having 40 W output are provided laterally in rows or vertically in columns in the frame main body as a grid, the total power generation becomes 400 W, and further when  10  units of the wind power generation system each having 40 W output are provided laterally and vertically, the total power generation becomes 4 KW. By increasing the number of units provided in the frame main body, a large amount of power generation may be possible. Meanwhile, referring to the aforementioned frame configuration, a wind direction key or vane  13  may be provided on upper part of the frame main body  1   a  and a rotatable support shaft or bearing  18  may be further provided on a lower part of the frame main body  1   a  and thus the whole frame main body  1   a  may be rotated depending by the wind via direction vane  13  around or on the shaft  18 , so the main tube bodies  1  may be rotated using upper and lower support rods  9   a ,  9   b , thereby increasing power generation efficiency depending on wind direction. 
     In particular, the occupation area of the wind power system according to the present invention may be decreased to less than ¼, comparing to that of the prior wind power system where only one power generation system is provided on one support rod. 
       FIG. 3  shows a front view of the wind power generation system shown in  FIG. 1 , wherein the same reference numerals indicated in  FIG. 3  for showing one wind power generation system are used in  FIGS. 5-10  for clarity and convenience. 
     Through the symmetrical rotation configuration of the wind power generation system according to the present invention, power is generated even in light wind and a smaller structure may be possible and thus a hundreds to thousands of power systems may be provided without limitations on locations. 
     While embodiments of the invention are described referring to the preferred embodiments, the invention is not limited thereto, and thus various variation and modification can be made without departing from a scope of the invention.