Abstract:
According to the invention, to use wind energy, a flow is conducted effectively onto a rotor to convert the flow energy by means of a steering mechanism. According to the invention, the steering mechanism permits: the wind to be conducted from a point of higher wind speed to a point of lower wind speed that is preferred for the installation of the rotor; the flow cross-section to be narrowed and compressed, thus increasing the flow speed; one side of a rotor with an axis running transversally to the wind direction to be shielded; and/or a suction effect to be generated downstream of the rotor in the flow direction. The device comprises a hollow tower ( 2 ) with a wind trap opening ( 5 ) at the upper end and a flow channel that is formed by the hollow cross-section of the tower ( 2 ), said channel leading downwards to at least one rotor ( 12; 14 ) that is located in the vicinity of the ground for converting the flow energy. An outlet ( 13 ) for the air is situated downstream of the rotor. An upper end section ( 3 ) of the tower comprising the wind trap opening ( 5 ) can be rotated ( 4 ).

Description:
BACKGROUND OF THE INVENTION 
     The invention pertains to a method and to a device for using wind energy. 
     SUMMARY OF THE INVENTION 
     The invention is based on the task of reducing the effort required to use wind energy based on the yield. 
     According to the invention, this task is accomplished in that, by directing the wind, the flow is effectively guided to a rotor for conversion of the flow energy. 
     There are many different possibilities for realizing the invention, and these possibilities can also be combined with each other, where the effective flow can be the wind itself, or it can be the diverted wind. 
     By directing the wind, it is possible 
     (a) to guide the wind from a point of higher wind velocity to a point of lower wind velocity more suitable for the installation of the rotor; 
     (b) to narrow the flow cross section, thus compressing the flow and increasing the flow velocity; 
     (c) to shield one side of a rotor in cases where the axis is transverse to the direction of the wind; and/or 
     (d) to generate a suction effect downstream from the rotor. 
     A device for implementing the method is characterized by at least one deflecting surface, which directs the wind in such a way that it can act on a rotor to convert the flow energy. 
     According to what was said above, there are many different means which can be used to implement the method. In particular, a light-weight structural approach with sheets, windsocks, or stretched-out sails mounted on frames can be used to realize the deflecting surfaces. 
     As a concrete embodiment, an alternative to a wind turbine is proposed, which is characterized by a hollow tower with a wind-capturing opening at the top and a flow channel formed in the hollow cross section of the tower, which leads downward to at least one rotor located near the ground to convert the flow energy, an outlet for the air being provided downstream of the rotor. 
     By arranging the rotor and the other pieces of equipment driven by the rotor on or at least near the ground, all of these devices can be simpler and cheaper and can be maintained more easily and more cheaply than the standard wind turbines, the bearings, gears, and generators of which are at a considerable height above the ground. 
     The tower can also be made of light-weight materials and thus at lower cost than in the case of wind turbines, because it can be braced by guy wires even at its greatest height. In contrast, wind turbines cannot be braced in the area where their vanes extend; that is, at least approximately the uppermost third of the tower cannot be braced; this section is simply left alone. In addition, the wind-capture opening of the tower can have a larger area than the total area of the vanes, which is limited by the tipping moment which develops. The possibility of bracing is especially advantageous for offshore use. For this application, towers, floating on pontoons, are especially suitable in any case because of their low center of gravity, which is much lower than that of wind turbines. 
     More complete use is made of the captured wind than in the case of wind turbines. The flow becomes more uniform over the length of the tower and drives the rotor more uniformly, whereas the actuating forces are often distributed nonuniformly over the vanes of a wind turbine. 
     The flow can be focused on rotors of smaller cross section, including the turbines. 
     Rotors with an axis aligned in the flow direction can be provided with a larger number of vanes. 
     It is also possible, however, to use rotors with an axis which is transverse to the flow direction. No more than half of such a rotor projects into the flow cross section, and its vanes are carried along directly by the flow. The cross section of the flow channel can also be changed, i.e., possibly converted from a round to a square form. Within limits, it can also be made smaller to increase the flow velocity and the air density, as already suggested above when reference was made to “focusing”. Systems of this type can also be protected from lightning more easily than wind turbines. The environmental burden is reduced in comparison with wind turbines; very little noise is generated, and no moving shadows are cast. Several devices can be set up relatively close together; that is, the energy yield per unit occupied by the devices is larger. 
     As a rule, the top end of the tower with the wind capture opening will be rotatable, so that the position of the wind capture opening can be adapted to changes in the direction of the wind. As an alternative, several openings, which can be opened and closed, can be provided on different sides. According to another advantageous embodiment, the height of the tower can be adjusted by means of telescoping sections. When the wind is strong, the tower can be shortened to a greater or lesser extent to reduce the force which the wind exerts on it and thus to prevent damage. The normal height of the wind capture opening can be approximately on the same order of magnitude as the height of the axis of a wind turbine. 
     According to an advantageous elaboration of the invention, the flow channel has branches, and one of the previously mentioned energy conversion units is installed in each branch, where preferably at least some of the branches can be closed off. 
     Because of the division of the flow channel into closable branches, the device can be adapted to different wind velocities in that, at lower wind velocities, only some of the energy-conversion units are put into operation, but the forces which actuate them will remain more-or-less the same. The units can thus always operate close to their optimum levels. Under certain conditions, however, it can be effective to work with branches which cannot be closed individually. 
     The towers provided in place of wind turbines experience the higher wind velocities prevailing at higher elevations. The inventive principle, however, can also be realized in many other different ways. In locations with strong winds, e.g., in the mountains or on bridges, it is possible to install, for example, windsocks with openings near the ground. The opening can be set up in such a way that it slants backward in a strong wind and tips over completely if necessary. It is also possible to provide simple wind scoops, from which a flow channel leads. 
     Instead of windsocks or other flow channels of closed cross section, it is also possible to stretch out sail-like deflecting walls, even over considerable distances, which act on a rotor at the end. 
     This rotor could be a wind turbine of conventional design, although smaller, and it could also stand directly in the wind. Thus, as a result of the coming-together of two flows, that is, considered overall, ultimately by the narrowing of the flow cross section, a compression would occur at the wind turbine. 
     The measures of flow guidance and rotor design mentioned above in conjunction with the tower can also be applied to a great extent to the other embodiments mentioned above. 
     As an especially advantageous elaboration of the invention, however, a device with a rotor with an axis oriented transversely to the wind direction is proposed, in which the rotor is surrounded on all sides by collecting and deflecting vanes, each of which is set at an angle to the radial direction relative to the rotor in such a way that it guides the wind striking it onto one side of the rotor and shields the other side of the rotor. 
     If the axis of the rotor is arranged vertically, the device can accept wind from any direction without adjustment. The device can therefore be made with large dimensions and installed in multiples, one on top of another. Multi-story tower structures offering maximum output are possible. 
     In accordance with another embodiment of the invention, the rotor vanes are provided with openings which become larger as the wind velocity increases. The positions of the collecting and deflecting vanes can also change in a corresponding manner. 
     In addition to the conversion of wind energy into electrical energy, some of the variants of the inventive devices also pertain to the conversion of wind energy into mechanical energy, e.g., for the direct drive of water pumps. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWING 
       The drawings illustrate an exemplary embodiment of the invention: 
         FIG. 1  shows a schematic front view of a device for using wind energy; 
         FIG. 2  shows a front view of a detail; 
         FIG. 3  shows an isometric projection of a detail of a different embodiment of a device for using wind energy; 
         FIG. 4  shows an axial view of the detail in  FIG. 3 ; 
         FIGS. 5-14  show schematic diagrams of additional devices for using wind energy; 
         FIG. 15  shows an isometric projection of the device according to  FIG. 14  in a multiple arrangement; 
         FIG. 16  shows a vertical cross section through the bottom section of the device according to  FIG. 15 ; 
         FIG. 17  shows a detail of  FIG. 16  on a larger scale; 
         FIG. 18  shows a top view of another detail of the device according to  FIG. 15 ; 
         FIGS. 19 and 20  show isometric projections of modifications of rotor vanes; and 
         FIG. 21  illustrates the effective principle cited above under point (d). 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       FIG. 1  shows a considerably shortened section of a tower  2 , the removed portion being taken from the area marked  1 , the static support at the base not being shown. 
     The top section  3  of the tower can rotate in a rotary bearing  4  around the vertical axis of the tower and is bent over to the side, so that its end, designed as a wind capture opening  5 , lies in a vertical plane. 
     The tower section  6  underneath the rotary bearing  4  is designed in such a way that it can slide telescopically in and out of a stationary tower section  7 . Beneath that is a tapered tower section  8 , which branches at the bottom end into two channels  10 . The two channels  10  can be closed as desired by a flap  11 , arranged in the center, as indicated in dash-dot line. In the middle position illustrated in the figure, the flap  11  leaves the entrances to both channels  10  open. 
     The presence of a rotor  12  is indicated in each channel  10 . Each rotor  12  drives a generator, installed outside the channel, possibly even underground. 
       FIGS. 3 and 4  show different types of rotors  14 . In contrast to the rotor  12 , the rotor  14  is to be imagined projecting into the channel  10  from a well in the side of the channel  10 . Outlets  13  at the ends of the channels  10  lead to the outside. 
     The way in which the device functions has already been described above. 
       FIG. 5  shows a windsock  15 , set up on the ground. 
     It has a rectangular entrance  16  and is made by stretching material over a frame (not shown), which is anchored to the ground. The entrance leads to a section of reduced cross section. A bellows-like intermediate section  17  makes it possible to shift the entrance  16  when the wind turns so that it can face the wind again. The windsock leads (arrow  18 ) to a rotor; the exact configuration will depend on where the rotor/generator unit, for example, is installed. An alternative orientation is shown in broken line. 
     The wind-capturing entrance  16  does not have to be rectangular; it could also be oval or circular or of some other shape. The possibility can be provided of tilting the entrance  16  backward or of having it fold all the way back in strong winds. Additional deflecting walls (not shown) could be provided to guide the wind, especially at low wind velocities, toward the entrance  16 . 
       FIG. 6  shows a system with a fan-like arrangement of wind scoops  19  pointing in all directions, which lead to a vertical flow channel  20 . An arrow  21  shows the wind direction. The wind is captured by the four wind scoops  19  which are facing the wind. It then passes into the flow channel  20 , which leads to a rotor/converter. 
     So that the air cannot escape through the other wind scoops  19 , their openings are closed by a shield  22 . In a weak wind, two collecting vanes  23 , shown in broken line, could be set up. The shield  22  would then be shortened so that all of the wind scoops  19  subject to the effect of the collecting vanes  23  are open to the flow channel  20 . 
     This system is intended for locations where the wind can come from any direction. 
     The system according to  FIG. 7  is also intended for wind from various directions. It has wind scoops  24  with a triangular cross section, which are directed toward two sides. A flow channel  25  leads out from each one. Wind from the directions of arrows  26  and  27  is captured directly by the wind scoops  24 . For wind from the direction according to the arrow  28 , collecting vanes  29  and, behind them, even larger vanes  30  are provided. The system is suitable for installation on bridges or across valleys. The wind scoops  24  and the collecting vanes  29  and  30  can be made of sailcloth or the like. The collecting vanes can thus also be rolled up. 
     According to  FIG. 8 , several flow channels  31 , which angle symmetrically away from each other, lead to a rotor  32 . These could be the flow channels  25  according to  FIG. 7 , but they could also come from a single original flow channel, which is divided into several subchannels. The rotor vanes  33  shown are straight. Preferably, however, they are bent slightly against the flow and/or optimized in some other way. 
       FIG. 9  shows a schematic diagram of a wind scoop  34  with the spiral shape of a snail shell. It consists of a fixed core part  35 , from which a vertical flow channel  36  extends, and a deformable wall  37 , shown in broken line, which can be bent into tighter or wider spirals so that the opening can be made to face wind coming from different directions. 
       FIG. 10  shows a device  38 , including its integrated rotor  39 , which is set up in the wind and which turns with the wind. The rotor  39  is mounted in a short air conduit  40 , which is designed as a collecting funnel  41  facing the wind. The conduit also has a necked-down section  42 , which shields half of the rotor  39  from the flow. At the outlet  43 , the air conduit  40  expands, so that the wind passing by around the outside of the air conduit  40 , as indicated here by the arrows  44 , exerts an increased suction effect. 
       FIG. 11  shows a device which operates in approximately the same way. It is not intended as an independent device, however, but rather as a unit to be installed, for example, at the end of the windsock  15  according to  FIG. 5 . It stands on the ground; the axis of the rotor is horizontal. An internal fitting  53  shields half of the rotor and simultaneously diverts the wind onto to the other half. 
       FIG. 12  shows a rotor  54  set up directly in the wind and provided with a shield  55  on one side. There is no need for a more complete explanation. It should be made clear, however, that it is not the diverted wind which represents the effective flow here but rather, because of the elimination of the countertorque, it is the undiverted part of the wind of which use is made. 
       FIG. 13  shows a relatively large wind collecting and deflecting surface  56 , which is brought up to the rotor  57  in such a way that it supplies the flow of air to half of the rotor and shields the other half. The collecting and deflecting surface  56  could be realized, for example, in the form of a masonry wall or by a sail. It could be installed in places where the wind blows essentially in only one direction, e.g., in specific valley locations. A sail could also extend down from above to a rotor with a horizontal axis. 
     The overall system designated  45  in  FIG. 14 , like the device  38  according to  FIG. 10 , is set up in the wind. It can accept wind from any direction. 
     A rotor  46  is surrounded by collecting and deflecting vanes  47 . Each collecting and deflecting vane  47  is set up at an angle to the radial direction so that it diverts the wind onto the rotor vanes on only one side of the rotor axis. The deflecting vanes are bent into a gentle S shape, so that they collect air more effectively on the outside and divert the air somewhat more to the side on the inside. 
     The vanes of the rotor  46  are bent slightly toward the wind. 
     On the downstream side of the rotor  46 , the air exits between the collecting and deflecting vanes  47  on that side. 
     The device according to  FIG. 14  is especially suitable for residential areas, e.g., on roofs. 
     The device is also especially suitable for being made as individual segments, which are arranged vertically. In other words, several of them can be stacked on top of each other. The system according to  FIG. 10  can also consist of several stories. The segments or stories would each have a height of approximately 20 m, for example. Thus, a modular structure with the corresponding advantages with respect to production, transport, construction, and maintenance becomes possible. Smaller generator units can also be used. 
     The rotors  39  and  46  can have a hollow space in the center, which can be used for various purposes such as a storage room or machine room. The generators could also be installed here. In the case of the arrangements according to  FIGS. 9 and 10 , the generators can be installed in rotational areas located farther outward and thus operate without gears. 
     It is also possible to install several generators on each modular unit; the number of generators put on line would depend on the velocity of the wind. 
     The rotors  39  and  46  could be provided with flywheel masses to reduce the effect of brief fluctuations in the wind velocity on the voltage stability. 
     The collecting and deflecting vanes  47  can be mounted with freedom to pivot, as indicated at  60  in  FIG. 14  by way of example, to increase the wind energy yield at low wind speeds or to reduce the supply of wind to the rotor, if necessary, such as during storms, or possibly to occupy a closed position to allow for repairs. 
     The collecting and deflecting vanes  47  could also be designed to telescope, so that their size can be increased. 
       FIG. 15  shows the previously mentioned multi-story arrangement of the system  45  according to  FIG. 14 . The diagram is broken off above the fourth system. It would be possible to imagine a tower structure with an overall height similar to that of a power plant cooling tower. 
       FIG. 16  shows how the complete system, designated  61 , can be constructed on the ground: 
     The lowermost system  45  is raised above the ground  63  on columns  62 . In the center is a closed structure  64 , through which the overall system  61  is accessible from below. In addition to stairs, elevators, etc., the structure  64  can accommodate offices, workshops, storage rooms, and the controls for the overall system. Stairs and/or elevators can be located more-or-less on the center vertical axis of the overall system. 
     Each system  45  has a foundation plate  65 , on which the collecting and deflecting vanes  47  stand, and a thinner cover plate  66 , supported by the vanes. The cover plate  66  is depressed at  67  toward the rotor  46  to accelerate the flow. The lines  68  are the outside edges of collecting and deflecting vanes  47 ; the narrow cross-sectional surfaces  69  are sections through the collecting and deflecting vanes  47 . The two cross-sectional surfaces designated  70  pass through the wall of the hollow cylinder  85  forming the central body of the rotor. The other visible terminal edges and cross-sectional surfaces will not be discussed individually. 
     The rotor  46  (see the detail circled in  FIG. 16  and shown on a larger scale in  FIG. 17 ) is rotatably supported by rollers  71  on a circular rail  73 , carried by a ring-shaped beam  72 . The ring-shaped beam  72  is recessed into the foundation plate  65 . 
     Four generators  74 , arranged symmetrically in a circle underneath the previously mentioned hollow cylinder, are, as illustrated in  FIG. 18 , driven by friction wheels or gear wheels  75 , which rest on the bottom surface of the wall of the hollow cylinder  80 . The arrangement  71 - 73  is not shown in  FIG. 18 . 
     Above the cover plate  66  appearing in  FIG. 16  is the foundation plate  65  of the next system  45 , comprising again all of the previously described parts  65 - 75 , and so on. 
       FIGS. 19 and 20  show variants of an elaboration of the invention, namely, variants in which the rotor vanes are provided with openings. 
     Three windows  77  are cut into the rotor vane  76  shown in  FIG. 19 , which is to be imagined as a vane of the rotor  46 . These windows can be closed by flaps  78 . The flaps  78  are held by springs  79  in such a way that they open more widely when the wind pressure increases. Even when the flaps  78  are closed there can still be an open gap, which allows a certain draft from the very beginning. 
       FIG. 20  shows a rotor  80  with rotor vanes  81 , each of which is formed by a plurality of individual segments  82 . The segments  82  are attached pivotably to the central body of the rotor  80  in such a way that they can be turned alternately in one direction or the other so that they can be moved from a position in which they are directly or almost directly next to each other and thus form a closed surface to a position in which they create free passages of greater or lesser size. 
       FIG. 21  illustrates the suction effect. A rotor  48  is mounted in an air conduit  49 , which does not expand in the direction facing the wind but rather toward the outlet  50 . The expansion at the outlet  50  forces the passing air (arrows  51 ) to increase its velocity, which thus increases the suction effect according to the principle of the jet pump. 
     The different functional principles described above under points (a), (b), (c), and (d) are used in the systems and devices illustrated and described above as follows: 
       FIG. 1 : (a) and (b); 
       FIG. 5 : (a) and (b), possible embodiments according to (c) and (d); 
       FIG. 6 : (a) and (b), possible embodiments according to (c) and (d); 
       FIG. 7 : (a) and (b), possible embodiments according to (c) and (d); 
       FIG. 9 : (a) and (b), possible embodiment according to (c); 
       FIG. 10 : (b), (c), and (d); 
       FIG. 11 : (b), (c), and (d); 
       FIG. 12 : (c); 
       FIG. 13 : (a) and (c); 
       FIG. 14 ,  15 : (b) and (c), possibly to some extent (d); and 
       FIG. 21 : (a). 
     The simplest way to realize functional principles (a) and (b) would be to set up a rotor in the lee of a house and to build a wall at an angle to the house to divert the wind to the rotor. In cooperation with an opposing wall of the house, the wind would be compressed at the same time. 
     In summary, the invention makes it possible to achieve the following in comparison with known systems:
         to increase the energy yield per unit volume or unit of useful area of the system;   to recover energy in areas where this cannot be done with current systems, such as in residential areas or in areas of difficult topography;   to recover wind energy at lower cost;   to design energy systems for higher nominal power outputs; and   to recover wind energy even at low and high wind speeds and/or to protect the systems more easily and more cheaply against storms, lightning strikes, etc.