Manufacturing of a wind turbine rotor blade

Abstract

Provided is a method of manufacturing a rotor blade of a wind turbine, the method including: placing fiber material on a shape forming surface; arranging phase change material being in a first state at at least one predetermined first region and/or arranging phase change material being in a second state at at least one predetermined second region; soaking the fiber material with resin to be in thermal contact with the phase change material at the first region and/or second region; during a crosslinking reaction for crosslinking the resin: absorbing heat generated within the resin by the phase change material at the first region; and/or releasing heat from the phase change material toward the resin at the second region.

Claims

1. A method of manufacturing a rotor blade of a wind turbine, the method comprising: placing fiber material on a shape forming surface; arranging phase change material being in a first state at at least one predetermined first region and arranging phase change material being in a second state at at least one predetermined second region; soaking the fiber material with resin to be in thermal contact with the phase change material at the first region and the second region; during a crosslinking reaction for crosslinking the resin: absorbing heat generated within the resin by the phase change material at the first region; and releasing heat from the phase change material toward the resin at the second region.

2. The method according to claim 1, wherein the first state allows absorbing heat and comprises a crystalline phase, or a first crystal phase of the phase change material, wherein the second state allows releasing heat and comprises a liquid phase or a second crystal phase of the phase change material.

3. The method according to claim 1, wherein the shape forming surface is provided by a first mould and defines a shape of a suction side or a pressure side of the rotor blade.

4. The method according to claim 1, further comprising: arranging a filling body at the fiber material on the shape forming surface, wherein the phase change material is arranged close to and/or at least partly embedded into the filling body and/or at least partly adhered to the filling body; wherein the fiber material is arranged at least partly around the filling body.

5. The method according to claim 4, wherein the filling body is in contact with an inside portion of fiber material and/or resin forming substantially half of a suction side or a pressure side and/or forming a leading edge or a trailing edge of the rotor blade.

6. The method according to claim 1, further comprising: arranging another filling body at the fiber material on the shape forming surface, wherein the phase change material is arranged close to and/or at least partly embedded into the other filling body and/or at least partly adhered to the other filling body; wherein the fiber material is arranged at least partly around the other filling body.

7. The method according to claim 6, wherein the other filling body is in contact with an inside portion of fiber material and/or resin forming substantially half of a pressure side or a suction side and/or forming a trailing edge or a leading edge of the rotor blade, wherein in particular by the filling body and the other filling body and the fiber material and the resin, substantially an entire inside space of the rotor blade is filled.

8. The method according to claim 1, further comprising forming an enforcement web connecting the suction side and the pressure side inside a completed rotor blade by: arranging a precast web portion in a root section between a filling body and an other filling body; arranging fiber material in a central to tip section to be between the filling body and the other filling body, and soaking the fiber material in the central to tip section between the filling body and the other filling body with resin and crosslinking.

9. The method according to claim 4, wherein the filling body comprises at least one first mounting region for mounting phase change material in the first state and/or wherein the filling body comprises at least one second mounting region, for mounting phase change material in the second state and/or wherein an other filling body comprises at least one other first mounting region for mounting phase change material in the first state and/or wherein the other filling body comprises at least one other second mounting region for mounting phase change material in the second state.

10. The method according to claim 9, wherein the first mounting region is located at and/or close to at least one of: the fiber material and resin finally forming at least a central portion of the enforcement web; the fiber material and resin finally forming at least a central portion of the pressure side and/or the suction side of the rotor blade.

11. The method according to claim 9, wherein the second mounting region is located, at and/or close to at least one of: a tip side end portion of the precast web portion in a central portion of the blade extending from a blade inner portion of the suction side to a blade inner portion of the pressure side; and a root end of the filling body and/or other filling body.

12. The method according to claim 9, wherein the first mounting region and/or second mounting region of the filling body and/or the other filling body allows reversibly mounting the phase change material at the respective filling body using an elastic material, and/or an adhesive tape, wherein the phase change material is contained in at least one pouch.

13. The method according to claim 1, further comprising: arranging another shape forming surface, at which fiber material is placed, onto a filling body and/or an other filling body; connecting an edge of the shape forming surface with an edge of the other shape forming surface) thereby enclosing the filling body and/or the other filling body and the fiber material on the shape forming surface and on the other shape forming surface and/or fiber material around the filling body and/or the other filling body; supplying resin to the enclosed fiber material utilizing vacuum assistance, wherein the other shape forming surface defines a shape of a pressure side or a suction side of the rotor blade; and heating from outside to initiate and/or accompany the crosslinking reaction of the resin.

14. The method according to claim 1, wherein during the crosslinking reaction the phase change material at the at least one first region at least partly transitions from the first phase to the second phase, and/or wherein during the crosslinking reaction the phase change material at the at least one second region at least partly transitions from the second phase to the first phase.

15. The method according to claim 1, further comprising, after the crosslinking reaction is completed: removing a filling body and/or an other filling body from the inside of the rotor blade with cured resin from the root portion; unmounting the phase change material at least at one first region and/or at least at one second region from the filling body and/or the other filling body; for manufacturing another rotor blade: mounting phase change material taken from the second region at the first region; and/or mounting phase change material taken from the first region at the second region.

Description

BRIEF DESCRIPTION

(1) Some of the embodiments will be described in detail, with references to the following Figures, wherein like designations denote like members, wherein:

(2) FIG. 1 schematically illustrates an elevational cross-sectional view of a wind turbine rotor blade during manufacturing according to an embodiment of the present invention;

(3) FIG. 2 schematically illustrates the wind turbine blade illustrated in FIG. 1 in a side cross-sectional view;

(4) FIG. 3 illustrates a first graph showing temperature profiles according to the conventional art and according to embodiments of the present invention; and

(5) FIG. 4 illustrates a second graph showing temperature profiles according to the conventional art and according to embodiments of the present invention.

DETAILED DESCRIPTION

(6) The illustration in the drawings is in schematic form. It is noted that in different figures, elements similar or identical in structure and/or function are provided with the same reference signs or with reference signs, which differ only within the first digit. A description of an element not described in one embodiment may be taken from a description of this element with respect to another embodiment.

(7) FIGS. 1 and 2 schematically illustrate a wind turbine rotor blade 1 during manufacturing comprising manufacturing equipment in a cross-sectional elevational view and a side view, respectively. Thereby, the rotation axis 3 around which the completed rotor blade 1 is to be rotated during normal operation is substantially perpendicular to the drawing plane of FIG. 1. FIG. 2 illustrates the wind turbine blade 1 in a cross-sectional side view, wherein the rotation axis 3 is substantially oriented vertically in FIG. 2. As can be seen in FIG. 2, a first mould portion 5 is placed on a ground 7 (or on a support). The first mould portion 5 comprises a shape forming surface 9 which is complementary to or defines a suction surface or a pressure surface of the rotor blade 1 to be manufactured.

(8) The completed rotor blade 1 has a leading edge 14 and a trailing edge 16.

(9) In a first manufacturing step, fiber material 11 is placed onto the shape forming surface 9. In the FIG. 2, this is only schematically illustrated depicting a gap between the shape forming surface 9 and the fiber material 11, for clarity of illustration. In reality, the fiber material 11 is directly placed onto the shape forming surface 9 of the first mould portion 5. Later on during manufacturing, the fiber material 11 will be soaked with resin thereby forming fiber material/resin 13. Later on, this mixture of resin and fiber material 13 will be crosslinked or cured in order to solidify, thereby actually forming the pressure side 15 or the suction side 17 of the rotor blade.

(10) As can be seen in FIG. 1, a filling body 19 has been arranged at the fiber material 11 which had been placed on the shape forming surface 9. The filling body 19 (and another filling body 25) has attached thereto phase change material 21 being in a first state at a predetermined first regions 23a, 23b, 23c, 23d. Phase change material 21 is also placed at the first region 23b as is illustrated in FIG. 2. Also, this PCM 21 in the first state arranged at the first region 23b is adhered or attached to the filling body 19 or to another filling body 25 which is also arranged at the fiber material 11 which had been arranged onto the shape forming surface 9 of the first mould portion 5. For example, the PCM 21 in the first state arranged at the first region 23b is attached to or received in a recess in the first filling body 19 and the other filling body 25 at an outer surface above and below the drawing page of FIG. 1 to be close to the pressure side 15 or the suction side 17 of the rotor blade.

(11) In FIG. 2, the filling body 19 and the other filling body 25 are not illustrated, since FIG. 2 is a cross-sectional view, wherein the cross-section is in a central portion wherein in the completed rotor blade, an enforcement web 27 will be formed. For the sake of clarity, the fiber material 11 as well as the fiber material soaked with resin 13 is not illustrated in FIG. 2 in this central section. Thus, the enforcement web 27 illustrated in FIG. 2 in the elevational cross-sectional view is finally also comprising fiber material and resin and will also be solidified during the crosslinking reaction. Thus, the fiber material/resin of the enforcement web as well as the fiber material/resin of the suction side 17 and/or the pressure side 15 will be in contact with the phase change material 21 in the first state at the first predetermined region 23a and 23b.

(12) Furthermore, the method comprises to arrange phase change material 29 at predetermined second regions 31a, 31b, 31c to be also in thermal contact with the fiber material 11 and/or the resin and the fiber material. Also, the PCM 29 in the second state is arranged close to or adhered or attached to the first filling body 19 and/or the other filling body 25. As can be seen in FIGS. 1 and 2, the filling body 19 as well as the other filling body 25 each are in contact with an inside portion of the fiber material and/or the resin forming a half of a suction side 17 or a half of a pressure side 15 of the rotor blade.

(13) The filling body 19 comprises a plane outer surface 33 facing a plane outer surface 35 of the other filling body. Within these plane surfaces 33, 35, a respective recess is provided to enable arranging the PCM in the first state 21 at the first region 23a and 23d, respectively. A similar recess is provided within the filling body 19 at the first region 23b close to the inside portion of the suction side 17. A similar recess is provided within the other filling body 25 at the first region 23c close to the inside portion of the pressure side 15.

(14) Furthermore, the filling body 19 as well as the other filling body 25 comprise recesses to allow attaching the PCM 29 in the second state at the predetermined second region 31a, 31b, 31c.

(15) The method further comprises forming the enforcement web 27 which eventually connects the suction side 17 and the pressure side 15 of the rotor blade in the inside of the completed rotor blade 1. Thereby, a precast web portion 37 is arranged in a root section 39 between the filling body 19 and the other filling body 25. Furthermore, fiber material 11 is arranged in a central-to-tip section 41 to be between the filling body 19 and the other filling body 25. Furthermore, the fiber material 11 in the central-to-tip section 41 is soaked with resin and is crosslinked.

(16) Depending on an analysis or simulation of the crosslinking reaction, one or more first regions or second regions to be filled with the PCM in the first state or the second state may be identified. Respective mounting regions at the filling body 19 and/or the other filling body 25 may be provided. The PCM may be attached to the filling body and/or the other filling body at the respective mounting locations. As can be seen in FIG. 1, the first mounting region 23a is close to the fiber material and resin finally forming at least a central portion of the enforcement web 27. Furthermore, the first region 23b is located at a location finally forming at least a central portion of the pressure side 15 and/or the suction side 17 of the rotor blade.

(17) As can be seen for example in FIG. 1, the second regions 31a, 31c are close to a root end 43 of the filling body 19 and/or the other filling body 25. The second region 31b is at a tip end portion of the precast web portion 37 in a central portion of the blade.

(18) In a next manufacturing step, another shape forming surface 45 of a second mould portion 47 at which also fiber material is placed is arranged onto the filling body 19 and/or the other filling body 25. Then, the edges 49 and 51 of the shape forming surface 9 and the other shape forming surface 45 are connected and sealed in a circumferential manner to enclose the filling body 19 and/or the other filling body 25 and the fiber material 11 and the resin. Then, resin is supplied into the space enclosed by the shape forming surface 9 and the other shape forming surface 45 which is not occupied by the filling bodies 19 and 25.

(19) Further, the method comprises to heat the resin from outside the mould formed by the moulding portions 5 and 47. In FIGS. 1 and 2, one or more inflow ports for introducing the resin and one or more outflow ports are not illustrated. Also heating equipment is not illustrated in detail. By heating the crosslinking reaction may be initiated. During the crosslinking reaction, phase change material at the first region 23a, 23b, 23c, 23d may transition from the first phase into the second phase and/or the phase change material at the second region 31a, 31b, 31c may transition from the second state to the first state, at least partly.

(20) After having completed the crosslinking reaction, the filling body 19 and the other filling body 25 may be removed from the inside of the rotor blade, in particular withdrawn from the root end section 43. The phase change material 21 at the first mounting regions 23a, 23b, 23c, 23d may be removed and also the phase change material 29 originally in the second state may be removed or unmounted from the filling body 19 and the other filling body 25. The respective phase change material 21, 29 may be checked for its state after having completed the crosslinking reaction. For manufacturing a next rotor blade, the respective phase change material may be prepared to be in a defined first state or a defined second state and may be mounted at the first region and the second region respectively. Ideally, it may be possible to simply swap several of the originally first state PCM and the originally second state PCM and mount it at the filling body and/or the other filling body 19, 25.

(21) The precast web 37 may comprise a cured epoxy laminate for example. The filling body 19, 25 may comprise a flexible foam or resilient foam.

(22) FIGS. 3 and 4 illustrate graphs showing temperature profiles during manufacturing according to a conventional method (FIG. 3) and according to embodiments of the present invention (FIG. 4).

(23) Therein, an abscissa 53 indicates the time, while an ordinate 55 indicates the temperature. The curve 57 illustrates the temperature profile of a hot spot. The curve 59 illustrates the temperature profile of a thick laminate, the curve 61 illustrates the temperature profile of a thin laminate and the curve 63 illustrates the temperature profile of a pre-casted part overlap.

(24) As can be taken from FIG. 4 compared to FIG. 3, the temperature of the hot spot is considerably decreased when using the phase change material at the respective hot spot regions, for example regions 23a, 23b illustrated in FIGS. 1 and 2. Furthermore, the pre-casted part overlap illustrated as curve 63 has increased temperature when the phase change material is placed at the second region, for example the second regions 31a, 31b, 31c.

(25) Therefore, the temperature is reduced in hot spot regions and is increased in cold spot regions, thereby enhancing the crosslinking reaction while not overheating so avoiding damaging of equipment such as the filling bodies.

(26) Although the present invention has been disclosed in the form of preferred embodiments and variations thereon, it will be understood that numerous additional modifications and variations could be made thereto without departing from the scope of the invention.

(27) For the sake of clarity, it is to be understood that the use of “a” or “an” throughout this application does not exclude a plurality, and “comprising” does not exclude other steps or elements.