Title of Invention

MODULAR TOWER TO SUPPORT A WIND-DRIVEN POWER-PLANT

Abstract

Tower for wind energy plant, that comprises of a machine car arranged on the tower and a rotor supported as a pivot on the machine car around an almost horizontal axis, that has at least one tutor blade with an upper, pipe-shaped tower section that is joined in a transit on region to a lower tower section designed as grid tower, whereby the grid tower has at easi three corner poles, whereby the upper lower section forms at least one-sixth of the total tower, the cross-section of the lower tower section below the transition region is greater than the cross-section of the upper tower section, and the transition region is designed in such a way, that a force-flow-optimized adaptation of the cross-section of the lower tower section to the cross-section of the upper tower section lakes place.

Full Text

1 Tower for Wind fcnergy Plant Modern wind energy plants arc mostly constructed with pipe towers, especially steel pipe towers, as this shell type construction is the simplest and most economic lower design. In large wind energy plants with more than 70 m rotor diameter and more than 80 in lower height, as well as a capacity of over 1.5 MW, the required tower diameter in the lower tower region is an important technical limitation. Diameters of more than 4.3 m can only be transported with dilticulty. as often the drive through height under bridges allow only smaller measurements. Furthermore, the total length and the dimensions of the to was requirc division into several tower sections that are bolted to one another by a ring flange joint. The large ring flange joints in lowers for very large wind energy plants (3 - 5 MW), apart from the logistics of transportation, also involve a significant tost factor. Therefore, on account of transportation difficulties, one is increasingly using concrete towers, which are either manufactured at the erection site of the wind energy plant or consist of small individual units that are adhered to one another and braced. Both types of towers are however significantly more expensive to manufacture than steel pipe towers. Due to this reason, even individual steel pipe -/concrete hybrid towers are built. in which the upper tower portion is constructed, as far as possible, as steel pipe tower, and only the lower tower part having dimensions that are too large for transportation is made of concrete. In this construction form however, the transition from steel tower to concrete lower has proved to be technically complex and cost-intensive. Besides, there are the widely known grid towers as current masts that are already being used for large wind energy plants up to a height of 114 m and a capacity of 2 MW. Apart from the advance of smooth transportation, these towers however have the important dteadvantage. that they have sinificantly larger hoizontal extensions than a comparable steel pipe tower or concrete tower, which frequently poses problems with the required distance between rotor blade tip and lower (blade free flow), If the rotor blade bends through heavily in a storm. there exits the danger of towcr contact, which is very dangerous for the emtire construction. 2 On the other hand, the larger horizontal extension of the grid tower allows an altogether more effective material utilisation. This generally known advantage of expert design allows smaller total dimensions and hence alfeta a lower purchase prica. This economic advantage however is neutralised generally by the costs incurred in maintenance of the grid lowers over their life span of 20 years. For example, the bolt joints in the highly dynamic loaded lowers in wind energy plants have to be periodically checked, which in the case of grid lowers having a large height implies an activity that is dangerous, time consuming and physically demanding, that can be carried out only by extremely specialized people used to working at heights. From the documents DE PS 736 454 and DE 198 02 210 Al it is known that the tower can have an upper and lower tower section, whereby the lower tower section is designed as grid tower and the upper tower section as pipe-type. Here however, problems occur with respect to the transition from a shell construction (pipe tower) to a special design (grid tower), as this is technically very demanding. In existing grid towers for wind energy plants therefore, generally a relatively short pipe- shaped component, the so-called 'cup", is used only indirectly under the machine car; this allows the transition to the machine car provided with a ring flange. There the transition is generally realised, in that four comer posts of the grid tower are screwed on to the cup directly on the outer side by means of bun strap joints. This concept is possible because the tower is subjected to only relatively low bending loads directly under the car. Thus, in this case, mainly only the horizontal (acting as transverse force of the tower) rotor thrust has to be transmitted. Further below, where the tower is mainly loaded by the bending moment acting from the rotor thrust though the lever arm of the tower length, such a design is not possible in a cost-effective manner, It is therefore the task of this Invention to present a lower design for large wind energy plams. which eliminates the disadvantages of the staic-of-the-art technology, particularly 3 with respect to the transportability, the cost-effectiveness, the maintenance and the blade This task is fulliledd with the help of a lower for a wind energy plant having the features as mentioned in vlaim 1. As is known from the state-of-the-art technology, the tower according to the invention consist of an upper pipe-shaped tower section as wall as the lower tower section that is designed as grid lower with at least three comer poles. Both tower sections are connected to one another in a transition region, whereby the dimensions of the upper tower section in the transition region are designed clearly leaser than the dimensions of the lower towcr section in the transition region. According to the invention. it is foreseen that the upper tower section is designed to form at least one sixth of the total tower. This offers the advantage that in the upper region of the tower a favourably standard design can be used. Besides that, the torsion loads occurring in the upper tower section are significantly higher than in the lower tower section on account of the smaller cross-section. As a pipe tower has high torsion rigidity, the torsion forces occurring can be better absorbed than by a grid tower. As already explained above, the transition from the lower to the upper tower section poses, a problem. The reason is, that the force flow from the pipe cross-section of the upper tower section has to be passed on to the three or even four corner poles of the lower lower section. The simplest solution would be a plate to which the upper and the lower tower sections are fixed. However, such a plate would have the disadvantage that the plate would have to have large measurements in order to withstand the loads coming into play, which again would translate into significantly more expenses. 4 According in the invention. it is also foreseen that the cross-section of the lower tower section below the transition region is greater than the cross-section of the upper tower section, whereby however the transition region is deigned in such a way, that a force- flow-optimised adaptation of the cross-section of thc lower lower section to the cross- secntion of the upper to war section takes place. The invention thus offer the advantage that a transition region is foreseen. that is designed in such away that thc force flow from the upper to this lower tower section is conducted in an optimum manner, so that the entire transition region does not have to be designed in an over dimensioned manner. The synergy of the above-mentioned features of the invention leads to an optimally designed lower The tower according to the invention has a standard tower in its upper region, In the lower tower section, which for example cannot be designed as pipe lower on account of its measurements, as it would then not be transportable, the tower according to the invention has a grid tower design. The prevision of a grid tower section in a wind energy plant erected offshore additionally has a big advantage that it offers lesser contact surface for the shaft loads than a pipe tower. The adapted transition region leads to a grid tower section whose comer poles and struts have lesser wall thickness, so that the dimensions of the lower and hence the costs for the tower, that account for a significant cost factor with respect to the total wind energy plant, gets reduced. Each comer pole can have an inclination with respect to the vertical axis of the tower that can be sdected in such a way that in case of a desired extension of the corner poles their longitudinal axes cross at a virtual intersection point. it is advantageous to design the tower according to this invention in such a way. that the virtual intersection point of the comer poles lies in the region above the transition region, which starting from the car can stretch over one-third of the tower length upwards of downwards. as the comer poles would thus be stressed mainly by normal forces and not by binding. Generally, grid towers have sinits between the corner poles for addition absorption of forces coming into play. By arranging the intersection point in the upper region of the wind energy plant, it is achieved that the force flow takes place predominantly through 5 the corner poles and the force flow pussing though the siruts is significantly lower. In this way the loads occurring in the struts can be imimized, whereby the struts could have smaller dimensions. i,e. the wall thickness of the struts can be selected lesser, whereby again the volume of weeding scams on thc leg connections can be reduced (cost saving). According to an advantageous extension of this invention, the transition region is designed in such a way that the cross-section of the lower lower section tapers-to the cross-section of the upper tower section and conforms to a length that it is at least hair the pipe tower diameter. According to further advantageous extension of the invention, the transition region is formed by a transition piece that is designed in such a way, that the horizontal extension in the lower region is significantly greater than the extension in the upper region. The bends thus occurring in the outer contour of the tower actually contradict general design rules, as particularly in the shell type constuction any kind of bend leads to increases in stress that could weaken the bearing structure. However, with the help of the pleasures mentioned in the sub-claims it is possible to neutralize the undisputed disadvantages of both the bending, points or to completely avoid the bending points, in order to fully utilize the advantages of the hybrid type construction according to the invention. In the state-of-the-art technology, such bends in the shell type construction are known from only very small wind energy plants, in which thy stress optimisation has never played any sigrnificant role. Instead, in the forefront was thc production technology that enabled joining of two pipe diameters easily available in the mariiet in a very simple manner. In such small machines (capacity below 300 KW), partly even available short pipe towers \were mounted on. lower parts made of pipes with larger diameters with the help of highly conical transition pieces. In modern wind energy plants with capacities greater than I MW, only pipe towers with slight bends (max- 5 - 8º) are economic in the state-of-the-art technology, whereby the bend is basically situated relatively close below the machine car. This design, know from 6 the document F.P 0821161.and referred to as "double conical pipe tower" mainly allows use of a large fastening flange on the joint position to the machine car and furthermore. serves thc purpose of adaptation of the self-frequency of the components to the rcquircments. According, to a further advantageous extension of the invention, it is a great advantage vo design the transition between the upper and lower lower section (if required, directly) below the horizolal plane, that is defined by the rotor blade tip when the rotor blade is standing vertically below. This measure allows us to avoid all the disadvantages present in the state-of-the-art technology in a simple manner. In the upper tower section, on account of the design as pipe tower, the requirements of a slim construction with cost-effectiveness not achieved so far is fulfilled, but also the simple maintainability with weather-protected risers and working space is significantly advantageous for the great height. As soon as the pipe tower reaches its transportation limits, the grid tower is used in the lower tower section beJow the level of the blade tip. With Us significantly greater horizontal extension this could facilitate material savings and hence also greater cost-effectiveness. The maintenance problem in the lower tower section is less important, as in the state-of-the-art technology one has hoist risers that allow accessibility for the maintenance personnel in the lower tower region in a simple and yet safe and comfortable manner. A further disadvantage of the grid towers, that has to be taken into account in winter when the large surface of the special design gets covered by ice and leads to additional mass is greatly reduced, as the addition mass now acts only on lower tower sections that are statically and dynamically much less critical. Due to the mentioned reasons it is advantageous to design the transition region at a distance from the rotor axis that could be 1.0 - 1.6 times, especially 1,0 - 1.3 times the rotor radius. 7 in order to facilitate the transportability) May of the transition. piece, it is of particular advantage to design the upper region of the transition piece in such a way, that while asscmbling the wind energy plant at the erection site it can be joined with the upper tower section, preferably by means of a detachable joint. Similarly it is also particularly advantageous to design the lower region of the transition picte in such a way, that the transition piece can be connetted to each corner pole of the grid tower by means of a detachable joint. It can also be advantageous it in addition to the corner poles, also a few struts are bolted with the lower region of the transition piece. The flange joint in the pipe tower should be categorised as particularly critical, as experiences with steel pipe-/concrete hybrid towers have shown. Therefore, another design form of the invention foresees that the detachable joint between the upper region of the transition piece and the upper tower section has an inner- lying double row boh flange as joint on the transition piece and a matching T-flange arranged on the upper lower section. Equipping this joint position with a large dimensioned double row flange additionally provides the advantage, that the flange simultaneously also serves as dent brace for the force deflection occurring in the bending point of the outer contour. In this way, the danger of a dent being caused by excessive stress is eliminated effectively to a great extent. The lower region of the transition piece is preferably designed in such a way. that it has joining points for butt strap joints to the corner poles of the grid tower. 8 As the lower grid tower gets the load of a significant additional mass due to the upper pipe tower. it is extremely advantageous to design the corner poles of the grid masts as hollow profile in order to prevent buckling due to the weight load of the pipe tower. The transition piece is further designed in such a manner, that the allowable transportation height is maintained by the structural height of the transition piece. The maximum possible iransportation height, on account of the limited drive-through height tinder bridges, is generally 4.3 m in Germany; in selected stretches even 5.5 m high goods can be transported. If in case of very large, wind energy plants (e.g. 3-5 MW capacity) transportation of the transition piece in one piece is not possible on account of the measurements, then for such cases an extension of this invention provides for design of the transition piece in at least two part-pieces joined to one mother in a detachable manner at the joining point. The joining, can. be done by ball flanges or butt strap joints; even welding of the part pieces at the construction site could be art economic solution, if the joining points are placed in zones, having less load. In this case, the transition piece can be divided into at least two part-pieces through a vertical division plane. Division into a number of identical pan-pieces conforming to the number of corner poles of the grid towers should be regarded as particularly cost- effective due to production-technical reasons. Another advantageous extension of the invention provides for a division of the transition piece in at least one horizontal division plane. Of course, in case of particularly large wind energy plants, even both division possibilities can be combined with one another. In order to fully utilise the maximum permissible transportation height to the greatest estent possible, an advantageous extension of the invention provides for a design of the 9 transition piese or the part-piece of the Transition piece in such a way, that it can be transported as boiler bridge with the help of adapter pieces that arc mounted on the available joining points or points that are created for this purpose. Dcpending on the measurement and weight of the transition piece or the part-picces of the transition piece, the transportation of several transition pieces or part pieces joined to one another directly or indirectly (through adapter pieces) can be foreseen in a boiler bride. This offers ihe possibility of bolting the part-pieces of a two-part transition piece having a very great structural height at the (half) ring flanges and then to transport it in a lying position as boiler bridge, adhering to the permissible transportation height. According to a design form as per the invention the transition piece can be designed in a particularly efficient manner, if it has a waiting and is finished in shell-type constuction. It is of particular advantage, if the basic shape of the transition piece largely conforms to a highly conical pipe whose average inclination of the wall to the centre axis is greater than the inclination of the wall to the lower region of the pipe tower and/or than the inclination of the upper region of the corner poles of the grid towers. The average inclination is defined as the angle between the vertical (even the centre line) and an imaginary line from the maximum horizotal extension in the upper region of the transition piece to the maximum horizontal extension in the lower region. In order to realize the strong expansion of the horizontal extension of the tower in the transition piece as per the invention, with respetf to the force flow, in a particularly advantageous manner, the average inclination of the wall of the transition piece to the centre axis should be 15°. preferably more than 25°. While using the conical pipe us basic shape of the transition piece, one can think of any random pipe cross-section, i.e. triangular rectangular, multi-cornered (e.g, ] 6-comered) 10 or event mund cross-sections. The invention further comprises of exelusvety conical pipes whose cross-section shape changes over the length. In a particularly advantageous extension, the cross-section of the transition piece changes from an almost Circular cross- section in the upper region. flowing into an almost multi- cotnered. prefecrably triangular or rectangular cross-section in the lower region. Almost round could also mean here multi-cornered. e,g. 16-cornered. If the joining to the pipe lower takes place through a ring flange, then with the help of this the transilion from the say l6-cornered transition piece to the round pipe tower can If at least the lower part of the pipe tower is also designed as multi-cornered, then the joining can also take place without any problems with the help of a butt strap joint. In case of different inclination of the side surfaces of the transition piece to the wall of the pipe tower, if required, in this case an additional dent brace has lo be provided. For saving on material and weight, it is particularly advantageous if the wall of the transition piece is provided with at least one recess. By skilfully shaping the recesses it is possible to improve the force flow as compared to the version without recesses. This holds good particularly for arch-shaped recesses that stretch from comer pole to corner pole. Further optimisation of the force flow can be achieved with the help of bulb-shaped or door frame shaped reinforcements at the edges of the arch-shaped recesses. For increasing the rigidity of the transition picce it is advantageous, if in thc lower region of the transition piece horizontal beams are formed between the comer poles of the grid tower, which join thc adjacent corner poles and/or the diagonally opposite comer poles with one another. These horizontal beams can be joined to the transition piece as a single piece, or even fastened through the butt strap joint between transition piece and corner poles. 11 Similarly, for increasing the rigidity of the transition piece, another extension of the invention provides for a design with libs iti a version with at least four corner poles; these ribs reinforce the joining lines of diagonally opposite corner poles. In a particularly advantageous design form, the transation piece is finished as cast component. The shaping flexibility of cast components allows a Shaping in such a way. that by means of soft, rounded transitions the stress excesses in the bending point of the welded steel construction variant can be avoided. A design particularly compatible for the force flow is achieved, if the wall of the transition piece is convexly bent when viewed in vertical section, as such a particularly smooth transition from the flange in the upper region to the corner poles in the lower region is achievable. Especially the inclination of the joining points in the lower region of the transition piece should he particularly designed in such a way that it conforms to the inclination of thc upper region of the comer poles of the grid towers. The cast design is also particularly advantageous in cast of multi-part transition pieces with vertical division planes, as in that case 4 identical cast parts are combined to form a transition piece (number effect). Casting materials preferred for the casting variant are steel casting or ball graphite casting, e.g. GGG 40.3. If the tower according to the invention is constructed with lesser number of pieces, then the finish of the transition piece as welding design is of particular advanuge, as the high costs incurred for form construction of the casting design is no longer applicable. 12 In the case of convcntional Lowers, as the transition to thc concrete base is often executed similarly with V-flanges, an advantageous extension of the invention provides a modular towcr construction series with the help of the hybird concept according to the invention. in which an existing pipe tower (e.g. a 80 m-lower for a 1.5 to 2 M W machine) with the help of the transition piece according to the invention is placed on under-parts in the grid towcr construction system of various heights. e,g. 30. 50 and 70 m high, in order to achieve total lower heights of 110, 130 and 150 m depending on the Silc location. In this way, even sites in interior, remote regions, considered as uneconomic till now, can also be considered for economic wind energy utilisation. According to another advantageous extension of the invention, the lower tower section designed as grid tower has several platforms arranged above one another, whereby a platform comprises of the corner poles and at least one strut running diagonally between the comer poles. According to a further advantageous extension of the invention, the inclination of the diagonally running strul in all platforms is designed identically, so that on account of the same inclination of the strut the joining points between the legs and struts are designed identical. This extension offers the advantage, that for joining the corner poles and the struts, identical nodes can be used. In this way, the structure of the tower can be optimised. Till now. the comer poles and the struts were adapted to one another while mounting together and then Welded in a very complicated marker. In comparison to welded nodal points, casting nodes can be designed much more compactly and hence in a more economic manner. Due to reasons of stability, welded nodal points should generally be finished in such a way, that welding seams do not overlap. This frequently calls for an extension of the nodes in the region of the pipe transitions, which is not necessary in case of a casting finish. For further improving the economic viability, between the modes ons can use standard pipe profiles, e.g. from pipeline construction, as comer poles or even as diagonal struts. The joining can be done either by bolt flange or by welded joints. 13 1, sing identical nodes offers the advantage that the notes can be produced be forehand and thc corner poles and the struts have to be welded or bulled during composition of luwer only in the nodal points. This means a significant reduction in workload during construction of grid tower. Besides there could be significant savings in costs during the production of identical nodes, on account of the series effect. Especially in offshore plants that have a grid towei, additional pipes will have to be provided for laying the cables for power connections. In offshore plants this offers an" additional contact surface for shalts, whereby additional loads act on the grid tower. Therefore. according to an advantageous extension of the invention, the cables for connectine the wind energy plant to the electrical supply mains are laid in the comer poles of the grid lower section, whereby one can achieve reduction of shaft loads, According to another advantageous extension of thc invention. cable protection pipes are pre-laid within the corner platforms, within which the cables run. These should preferably be finished as plastic pipes, and allow smooth drawing-in of the cables after the tower has been, erected, and anchored on the seabud. Further features, aspects and advantages of the invention are revealed partly through the following description and partly explained by the description or can be seen in the practical application of the invention. Two design forms of the invention are explained in details. It is obvious that other design forms can be used and changes effected without leaving he scope of this invention. Therefore, the following detailed description should not be viewed in a restricted sense; even details of both design forms can be exchanged as desired. The invention is supposed to be described in details on the basis of the following diagrams. The following are shown: Fig. 1 Wind energy plant as in the state-of-the-art technology Fig. 2: Total view of the tower design as per the invention Fig, 3: A detailed depiction of a design form of a transition piece according to the invention. Fig.4: A detailed depiction of another design form of a transition piece according to the invention Fig.5: Development of the wall of the transition piece from fig. 4. Fig. 1 shows the depiction of a wind energy plant as in the state-of-the-art technology, in which as supporting lower (10) two tower variants, a pipe tower (10A) and a grid lower (IOB), are projected above one another. The tower (10) supports a machine car (30) fixed in a binged manner around the vertical tower axis, on which a rotor (20) with at least one rotor blade (22) with a blade tip (23) is pivoted around an almost horizontal axis. Here a design as, three-blade-rotor is shown, whereby the horizontal plane of the rotor blade lip (23) in the lower position is marked by a dished line (25). Apart from the rotor bearing, the machine car (30) generally contains a generator, if required a gear system, a wind follow-up system, various electrical components and additional auxiliary systems. These elements are not shown due to reasons of better overview. Due to transportation reasons, the pipe tower (10) has several flange joints 12A. These flange joints arc designed in the state-of-the-art technology as single-sided ring flanges gcnerally pointing inwards. Only the lowest flange acting as transition to the base (18A) is designed in the state-of-the-art technology as T-flange (double row flange pointing inwards and outwards). In a design variant as grid lower (10B). the transition to the ring-shaped flange of the machine car is generally realised by means of a relatively short transition piece (14B) known an cup. The grid lower rests on bascs (18B) generally designed individually for each corner pole (HB). 15 From the towcr variams. pipe lower (10) A) and grid tower (10B). projecting above one another it can X very clearly seen in the level of thc rotor blade tips (25) that the distance of the blade up to thc anker blade free run) in case of grid tower (I0B) is very much lesser and hence is more critical than in the case of the pipe tower (I0A). Fig. 2 shows the total view of the wind energy plant with a tower design according to the invention. As in fig. 1. (20) denotes the rotor and (30) denotes the machine car. in thc lowen section (41) the lower (40) consists of a grid lower (42) that is equipped in the shown design example with four comer poles (43) and a large number of diagonal struts (44), and in the upper section (46) is consists of a largely pipe-shaped pipe tower (47). Joining of the grid tower (42) and the pipe tower (47) takes place in a transition region that is designed in such a way, that a force-flow-optimised adaptation of the cross-section of the grid tower to the pipe tower takes place. Here, by force-flow -optimised adaptation one refers to a design finish that either creates a smooth geometric transition between the different crosa-section forms of the upper and lower tower section by means of a continuous change in geometry, and thus avoids stress peaks in the transition region, and/or diverts stress peaks in the transition region through suitable ribs and/or struts in the joining design. The pre-requisite for force-flow optimum transition in the erected condition is a vertical length of the transition region of at least the length of the radius of the lower pipe lower diameter and/or application of bearing elements (shells, ribs, struls) that essentially join the corner poles of the lower grid mast with the wall of the upper pipe tower. In the design example shown, the transition region is designed in such a way, that directiy below he horizontal plane (25) of the rotor blade lip (23) a transition piece (50) is arranged. whose horizontal extension in the lower region (70) is significantly greater (by more than 50%) than in the upper region (60). 16 The upper tower section (46) has in the lower region an (slight) inclination of the pipe wall it the vertical which is denoted by a. In an analogous manner, the inclination of the uppcr region of the corner pole (43) of the grid to wet (42) in the lower tower section (4) is; denoted by b. For as optimum grid tower section, the corner poles (45) have an inclination that is selected in such a manner, that the corner poles (43), in ease of a desired extension of the corner poles (43) (shown in fig, 2 by a dashed line). meet at a virtual intersection point VS. The position of the virtual intersection poim is arrangcd in the shown design example in a region that, viewed from the car, extends downward by one-third of the lower length. Depending on the combination of the tramsverse force and bending moment in the dimensioned load case, the optimum virtual intersection point can lie above the car. The average inclination of the transition piece (50) that is defined as the angle between the vertical and an imaginary line from the maximum horizontal extension in the upper region (50) to the maximum horizontal extension in the lower region (70), is denoted by X h\ the siovm design form of ihe invention, that is piailit\iiady advantageous, ^ is significantly greater than the inclination ({J) ol'the lower tower section (41) as well JIS the inclination (tit) of the upper tower section. However, it is also conceivable that the individual corner poles are bent and hence have different inclinations, whweby h^re too an average inclination of the corner poles analogojus to the transition piece can be defined. Fig. 3 shows & detailed depletion of a possible design variant of trie tower according to: the inve ilitin, with a transition piece as muJti-part casting construction. To the right of ihi; svmmeln line the side view is ahviwrv. on the laft sida is itwi depittion in {vertical) actiion. The \wcr tower section is fonrted by the grid tow^r (42) Lhat is shown sectioned 17 and mainly consists of four corner pales (43) and the diagonal struts (44). The upper lower section is formed by the shown sectioned pipe tower (47) with its wall (48). A version of the transition piece (50) according to the invention is designed as casting contraction in shell type construction with a wall (52) and arch-shaped recesses (53). The transition piece is joined in the upper region (60) to the pipe lower (47) by a flange joint (61) and in the lower region (70) to the comer poles (43) of the grid tower (42) by four butt strap joints (71). In the upper region (60) of the transition piece (50) the wall (52) smoothly flows into a ring-shaped, double row boll flange (64). The wall (48) of the pipe tower (47) is welded with a T-flange (62). which is bolted through an inner bolts circle (63) and an outer bolts circle (68) to the flange (64) of the transition piece (50). The inner bolt joint (66) is executed as a penetrating bolt joint generally used in steel construction. the outcr bolt joint (48) is designed in the shown example as blind hole bolt joint, because in this way a wall thickness distribution of the wall (52) that is particularly favourable for the force- flow is possible. Obviously the wail (52) of live transition picce (50) can also be drawn out somewhat further outwards, so that even the outer bolt joint (68) can be executed as a penetrating bolt joint; however, in that case the transition piece (50) will become some what heavier and hence costlier. In the lower region (70) the wall (52) runs across four joining points (72) to the comer poles (43). The joint is done as butt strap joint (7l) through an outer strap (76) and an inner strap (78) that are screwed with several bolts to the joining points (72) and the corner poles (43). As the inclination of the joining points (72) and the inclination of the tipper re gion. of the comer pole (411 are identical., smooth platcs can be used as joining straps (76, 78). With a view to reducing, the number of parts, yet another design form of the invention has a direct rolled joint joining the comer poles (43) with the joining points (72) of the 18 transition picce (50). Howere. in this design form, the force flow from the corner pule (43) into the wall (52) of the transition piece (50) is somewhat more favourable. For rein forcing the lower region (70) of the transition piece (50). horizontal beams (45) are fixed between thc comer poles (43). These beams could join either the adjacent corner poles (43) or the opposite corner poles (43) and hence the diagonals of the grid lower (42) to one another. If required even both possibilities can be used together in order to facilitate a particularly rigid and hence advantageous construction. Joining of the diagonal struts (44) and the horizontal beams (45) to the butt strap joints (71) is not shown due to reasons of simplicity. Such joints are however very well known in the state-of-the-art technology, e.g. for joining multi-part comer poles. For an outer diameter of the T-flange (62) of the pipe tower (47) of 4.3 m the shown transition piece (50) shows a transportation height of similarly above 4,3 m with a lower transpanation width of about 7 m. A these measurements can only be transported in a restricted manner, another preferred design form of the invention provides for a multi- part desing of the transition piece (50). For this, the transition piece (50) is divided into a left part-piece (57) and a right part-piece (58) through a vertical division plane. The part pieces (57, 58) are boiled with one another by bolt flanges (56). As an alternative to the bolt flange (56), another advantageous extension of the invention provites butt strap joints for joining the part-pieces (57, 58) of the transition piece (50). By means of the division, the transportation dimensions for transportation in a lying condition for both part-pieces (57, 58) get reduced to a transportation height of about 2.5 m for a width of 4.3 m, whereby within Germany transportation is possible without any problems. Another advantageous extension of the invention provides for a four-division of the transition piece symmetric to the centre line, so that either even smaller transportation dimcnsions can be achieved, or even larger transition pieces can rcmain transportable in a 19 smooth manner. In case of very large transition pieces. The invention provided for division of the transition pieces additionally in a horizontal plane. 'Ihe shown design example of the transition piece as casting construction has the advantage, that thc wall (52) can be designed without any problem, with vaiying wall thickness, whereby one can obtain a very efficient material utilisation. The regions having high load. e.g. the convex bent transition to the ring flange (64) or the joining point (72) in the corner poles (43) of thc grid tower (42) designed as butt strap joim (71) can be designed with larger wall thickness than regions having lesser loads. Similarly, the bordering of the arch-shaped recess (52) can be provided with bulge-type reinforcement Furthermore, the casting construction allows a sliding transition optim sed for the force flow from the round cross-section in the upper region (60) of the transition piece (50) to the shown case of rectangular cross-section in the lower region (70) of the transition piece (50). Especially in the offshore application of the tower concept according to the invention, it is advantageous to utilise the space available in the transition region in a sensible manner, in that electrical operating agents (converters, switching devices, transformers), a spare parts storage (if required, with a small workshop) or an emergency accommodation for maintiance personnel or even a visitors room is accommodated there. For this, the available supporting structure can be supplemented with addition walls to form a closed space, which is obviously equipped with the required emergency entries and exits and eventually also with windows and air-conditioning systems. For the insulation of the electrical operating agents in the transition piece, an advantageous extension of the invention foresees that these operating agents are installed already in the factory and tested and the transition piece with the installation is transported and installed as a so- called power module. Fig. 4 shows the detailed depiction of another design variant of the transition piece according to the invention as welding construction. In the lower part of fig. 4, a top view 20 is slawn from the lop on to the transition piece (50). as well as in the upper part a vertical section through the transition piece along the section line A-B is shown. As the basic structure is very similar to the design explained in detail in fig. 3, one is referring only mainly to the differences. The wall (52) of the transition piece (50) is formed by 3 plate having constant thickness. which is rollcd-in in the upper region and founded in the lower region (70) for adapting to the geomeiry of the corner poles (43). The average indination (x) of the transition piece (50) that is defined as the angle between the vertical and an imaginary line from the maximum horizontal extension in the upper region (60) to the maximum horizontal extension in the lower region (70). is significantly greater than the inclination of the corner polcs (43) of the grid tower (42), and obviously eiso greater than that, of the pipe tower, as this is designed in the shown example as cylindrical. Use 01 a cylindrical pipe tower allows a cost-favourable production and is only possible because the grid tower is designed very as very rigid/stiff and hence the total structure can also be designed in a sufficiently rigid/stiff manner, if a reinforcement- increasing expansion of the pipe tower is dispensed with. Using a cylindrical shape for a pipe tower is ideal if the azimuth bearing (rotate-able arrangement of the car on the lower) is selected sufficiently large. as in that, case a sufficiently rigid finish of the pipe tower is possible without expansion. In view of a simple design of the welding structure the joining point (72) has in the lower region n70) of the transition piece (50) an inclination that is different from the inclination of the cpmer poles (43). Therefore, the joining takes place through sufficiency thickly dimensioncd, bent butt straps (76) (hat have to take up the deflection of the force flow. The bent straps could be made of steel plate and weided if required, but an extension of the invention also provides for designing the straps as casting components. 21 As the forcc deflection deforns the butt strap joints inwards (towards the lower axis). thickly dimensioned hanizontal bearas (45) arc provided diagonally between two cormer poles (43) lying opposite to one another. (Due to reasons of simplicily, in the lower poles of fig. 4 only one such torn (45) has been shown as dashed line). With ihe help of this type of coustunction the deflection of the force flow can be safely controlled and one also obtains a very economic, but however a so me what hcavier structure than in the ease of the cast structure. Just us in the cast structure, an advantageous extension of the invention provides reinfdrcemenl of the arch-shaped recesses (53), that are designed in the fonn of a welded plate strip (55) (as in a door frame). The advantages of desk; nine as wclded structure are the favourable manufacturing costs for lessor numbers, and the simpler testing procedures with the construction authorities. Fig. 5 shows the progression of the wail of ihe transition piece according to the invention shown in fig. 4. This structurally very favourable skapc can be produced in a very simple manner by plates out-out from a steel plate in a single piece or as in the depicted case of the grill tower, with four corner poles in 4 pieces (indicated by dashed line). The plate(s) is/arc additionally roiled in conically, in the transition region to the corner poles additional rounding off is of advantage, in order to ensure a belter transition to the comer polts. If sufficiently large rolling machines Eire not available, then the largely round shape at the transition to the upper flange can also be created by several smaller chamfers. The invention is particularly characterised by Lhe following claimed features that are even independent of onc another: A lower for a wind energy plant, whereby the detachable joint (61) between the upper region (60) of the transition piece (50) and the upper tower section (46) has a double row bolt flange (64) arranged as joining point on the transition piece (50) and a T- flange (62) ar0ranged on the upper tower section (46). 22 A tower lor a wind energy plain, in which the lower region (70) of the transition piece (50) has joining points (72) for butt strap joints (71) to the corner poles (43) of the grid tower (42). A tower (40) for wind energy plant, in which the structural height of the transition piece. (50) is limited by the drive-through height below bridges and is between 2 m and 6 m. preferably between 4 in and 5.5 m. A tower (40) for a wind energy plant, in which the transition piece (50) has at least one vertical division, plane. A lower (40) for a wind energy planL in which the transition piece (50) has at least oue horizontal division plane. A tower (40) for a wind energy plant, in which the transition piece (50) or the part-pieces (57, 58) of the transition piece (50) is designed in such a way. that it can be transported as boiler bridge with the help of adapter pieces that are mounted on the available (56, 64, 72) joining points or new joining point provided for this purpose- A tower (40) for a wind energy plant, whereby the transition piece (50) or the part-pieces (57 58) of the transition piece (50) is/are shaped in such a way. that transportation of several transition pieces (50) or part-pieces (57, 58) dirently or indirctlly joined toone another can be carried out in a boiler bridge, A tower (40) for a wind energy plant, in which the Transition piece (50) has a wall (52) and is deigned as shell type construed on, A tower (40) for a wind energy plant, where the basic shape of the transition piece (50) largely corresponds to a highly conical pipe, whereby the average inclination (x) of the wall (52) of the conical pipe to the centre axis is greater than the inclination (a) of the 23 wall (48) of the lower region of the pipe lower (47) and/or than the inclination (b) of the upper region of the corner poles (43) of the grid tower (42). A tower (40) for a wind energy plant, whereby the average inclination (x) of the wall (52) of the transition piece (50) to the centre axis is at least, 15º, preferably more than 25°. A lower (42) for a wind energy plan, in which the transition piece (50) changes from an almost round cross-setion in the upper region (60) flowing into a multi-comered, preferably triangular or rectangular crops-section in the lower region (70). A lower (40) for a wind energy plant, in which the wall (52) of the transition piece (50) is provided with at least one recess (53). A tower (40) for a wind energy plant, in which the at leapt one recess (53) is arch-shaped and the arch-shaped recess (53) stretches from corner pole (43) in corner pole (43). A tower (40) for a wind energy plant, in which the at least one arch-shape recess is provided with reinforcements (55) of the bulge-type or door-frame type. A tower (40) for a wind energy plant, whereby in the lower region (70) of the transition piece (50) horizonial beams (45) are formed between the corner pole (43) of the grid tower (12), which joins the adjacent corner poles (43) and/or the diagonally opposite corner pole (43) with one another. A lower (40) for a wind energy plant, whereby the grid tower (42) has at least four corner poles (43) and the transition piece (50) has ribs that reinforce the joining lines of opposite corner foles (43) (diagonally opposite), A lower (40) for a wind energy plam. in which the transition piece (50) is designed as casting part. 24 -\ lower (4) for a mind energy plant. in which the wall (52) of the transition piece (50) is convexly bent in the vertical section. A lower (40) for a wind energy plant, in which the inclination of the joining point (72) in the lower region (711) of the transition piece (50) corresponds to the inclination of the upper region of the comer poles (43) of the grid tower (42). A tower (40) for a wind energy plant, in which the transition piece (50) is designed as welded structure. A tower (40) for a wind energy plant whereby the lower lower section (41) designed as grid lower (42) as several sections arranged above one another and a section comprises respectively the corner poles (43) and at least one strul (44) running diagonally between the corner poles. A tower (40) for a wind energy plant, in which the inclination of the struts running diagorally is desired identical in all sections. A lower (40) for a wind energy plant, whereby cables for connecting the wind energy plant to the elcclrical power supply are laid in the corner poles (43) designed as hollow profile A tower (40) for a wind energy plant, in which within the comer poles (43) cable protect on pipes are laid. withtin which cables ran. 25 PATENT CLAIMS 1. Tower (40) for a wind energy plant. which comprises of a machine car (30) arranged on the tower (40) and a rotor (20) supported as n pivol on the machine car around an almost horizontal axis, that has at least one rotor blade (22) with an upper-pipc-shaped lower section (46) that is jointed in a transition region to a lower tower section (41) designed as grid tower (42), whereby the grid tower (42) has at least three comer pates (43), having the distinctive feature that the upper tower section (46) forms at least one sixth of the total tower the cross- section of the lower tower section (41) below the transition region is greater than the cross-section of the upper tower section (46), and the transition region is shaped in such a way that a force-flow-optirmzed adaptation of the cross-section of the lower tower section to the cross-section of the upper lower section takes place, 2. Tower (40) for a wind energy plant as per claim 1, having the distinctive feature that the vertical extension of the tranational region has at least half the diameter of the upper tower section in the transition region or directly borders along it. 3. Tower (40) for a wind energy plant as per the previous claim, having the distinctive feature that the transition region tapers upwards from the cross-section of the lower lower section. (41 Ho the cross-section, of the upper tower section (46). 4. lower (401 for a wind energy plant 33 per one of the previous claims. having the distinctive feature that the transtion region is formed by 3 transition piece (5D) that hto a lower region (70) that can be joined to the tower tower section (41), and an upper region (60) Ihat can be joined to the upper tower section (46). 26 5. Tewer (40) for a wind energy plant as per one of thc previous claims. having the distinctive feature that the lower region (70) of the transition piece is designed in such a way, that its largest horizontal extension is at least 30%. preferably more Than 50% greater than a horizontal extension of the upper region (60), 6. Tower (40) Tor a wind energy plant as per one of the previous claims, having the distinctive feature that thc lower (40) is designed in such a way, that the transition piece (50) is arranged below the horizontal plane (25) that is defined from the blade tip (23) when the rotor blade (22) is standing vertically downward. 7. lower (40) for a wind energy plant as per one of the previous claims, having the distinctive feature I hat the upper region (60) of the transition piece (50) ts designed in such a way, that the transition piece (50) can be joined to the upper tower section (46) by means of a detachable joint (61), 8. Tower (40) for a wind energy plant as per one of the previous claims, having the distinctive feature that the lower region (70) of the transition piece (50) is designed in such a way, that he transition piece (50) can be joined in each corner pole (43) of the grid tower (42) with the help of a detachable joint (71). 9. Tower (40) for a wind energy plant as per one of the previous claims, living the distinctive feature that he transition piece (50) is formed with al least two part-pieces (57, 58) preferably joined to one another in a detachable manner it the joining point (56). 27 10. Modular tower system for a wind energy plant preferably as per one of the previous claims. consisting of an upper tower section that is largely pipe-shaped. as well as various lower lower sections designed as grid tower, having the distinctive feature that The total tower height can be dcsigned to be variable thtough different structural hieght of the grid tower. Tower for wind energy plant, that comprises of a machine car arranged on the tower and a rotor supported as a pivot on the machine car around an almost horizontal axis, that has at least one tutor blade with an upper, pipe-shaped tower section that is joined in a transit on region to a lower tower section designed as grid tower, whereby the grid tower has at easi three corner poles, whereby the upper lower section forms at least one-sixth of the total tower, the cross-section of the lower tower section below the transition region is greater than the cross-section of the upper tower section, and the transition region is designed in such a way, that a force-flow-optimized adaptation of the cross-section of the lower tower section to the cross-section of the upper tower section lakes place.

Documents:

00640-kolnp-2006-abstract.pdf

00640-kolnp-2006-claims.pdf

00640-kolnp-2006-description complete.pdf

00640-kolnp-2006-drawings.pdf

00640-kolnp-2006-form 1.pdf

00640-kolnp-2006-form 2.pdf

00640-kolnp-2006-form 3.pdf

00640-kolnp-2006-form 5.pdf

00640-kolnp-2006-international publication.pdf

00640-kolnp-2006-international search report.pdf

640-KOLNP-2006-(08-11-2011)-CORRESPONDENCE.pdf

640-KOLNP-2006-(08-11-2011)-OTHERS.pdf

640-KOLNP-2006-(24-04-2012)-CORRESPONDENCE.pdf

640-KOLNP-2006-(24-04-2012)-OTHERS.pdf

640-KOLNP-2006-ABSTRACT-1.1.pdf

640-KOLNP-2006-CLAIMS-1.1.pdf

640-KOLNP-2006-CLAIMS.pdf

640-KOLNP-2006-CORRESPONDENCE 1.3.pdf

640-KOLNP-2006-CORRESPONDENCE 1.4.pdf

640-KOLNP-2006-CORRESPONDENCE-1.1.pdf

640-KOLNP-2006-CORRESPONDENCE-1.2.pdf

640-KOLNP-2006-CORRESPONDENCE.pdf

640-KOLNP-2006-EXAMINATION REPORT.pdf

640-KOLNP-2006-FORM 1-1.1.pdf

640-KOLNP-2006-FORM 18.pdf

640-KOLNP-2006-FORM 2-1.1.pdf

640-KOLNP-2006-FORM 26.pdf

640-KOLNP-2006-FORM 3.pdf

640-KOLNP-2006-FORM 5.pdf

640-KOLNP-2006-GRANTED-ABSTRACT.pdf

640-KOLNP-2006-GRANTED-CLAIMS.pdf

640-KOLNP-2006-GRANTED-DESCRIPTION (COMPLETE).pdf

640-KOLNP-2006-GRANTED-DRAWINGS.pdf

640-KOLNP-2006-GRANTED-FORM 1.pdf

640-KOLNP-2006-GRANTED-FORM 2.pdf

640-KOLNP-2006-GRANTED-LETTER PATENT.pdf

640-KOLNP-2006-GRANTED-SPECIFICATION.pdf

640-KOLNP-2006-OTHERS DOCUMENTS.pdf

640-KOLNP-2006-OTHERS.pdf

640-KOLNP-2006-REPLY TO EXAMINATION REPORT.pdf

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