阅读说明：本技术 制造风力涡轮机转子叶片的方法 (method of manufacturing a wind turbine rotor blade ) 是由 P.B.埃内沃尔德森 S.F.普尔森 于 2019-06-06 设计创作，主要内容包括：本发明描述了一种制造风力涡轮机转子叶片(1)的方法,其中,每个转子叶片(1)包括内侧部段(1A)和外侧部段(1B),并且其中：使用第一铸造工艺(P1)来制造包括根端(10)和过渡区域(11)的内侧叶片部段(1A)；以及使用第二铸造工艺(P2)来制造包括翼型区域(12)的外侧叶片部段(1B),所述第二铸造工艺(P2)不同于所述第一铸造工艺(P1)。本发明还描述了使用这种方法制造的风力涡轮机转子叶片。(The invention describes a method of manufacturing wind turbine rotor blades (1), wherein each rotor blade (1) comprises an inboard section (1A) and an outboard section (1B), and wherein: manufacturing an inboard blade section (1A) comprising a root end (10) and a transition region (11) using a first casting process (P1); and manufacturing an outboard blade section (1B) comprising an airfoil region (12) using a second casting process (P2), the second casting process (P2) being different from the first casting process (P1). The invention also describes a wind turbine rotor blade manufactured using such a method.)

1. A method of manufacturing wind turbine rotor blades (1), wherein each rotor blade (1) comprises an inboard section (1A) and an outboard section (1B), and wherein,

-manufacturing an inboard blade section (1A) comprising a root end (10) and a transition region (11) using a first casting process (P1); and

-manufacturing an outboard blade section (1B) comprising an airfoil region (12) using a second casting process (P2), the second casting process (P2) being different from the first casting process (P1).

2. the method according to claim 1, wherein the first casting process (P1) is a mould-open casting process.

3. a method according to claim 1 or claim 2, wherein the second casting process (P2) is a closed mould process.

4. The method according to any of the preceding claims, comprising the steps of: a connector interface (14) is provided between the blade sections (1A, 1B).

5. The method according to any of the preceding claims, comprising the steps of: the inboard blade section (1A) is coupled to the outboard blade section (1B) to complete the rotor blade (1).

6. The method according to any of the preceding claims, comprising the steps of:

-scheduling two simultaneous workflow phases (S1, S2);

-producing three lateral sections (1B) and one medial section (1A) during one workflow stage (S1); and

-manufacturing two inner sections (1A) during another workflow stage (S2).

7. The method according to any of the preceding claims, wherein the duration of the workflow stage (S1, S2) is determined based on the time required for manufacturing the inner blade section (1A).

8. The method according to any of the preceding claims, wherein the blade sections (1A, 1B) are coupled during one of two casting processes (P1, P2).

9. The method according to any one of claims 1 to 7, wherein the blade sections (1A, 1B) are joined after completion of two casting processes (P1, P2).

10. A wind turbine rotor blade (1) manufactured using the method according to any of claims 1 to 9.

11. Wind turbine rotor blade according to claim 10, wherein an inner blade section (1A) comprises the blade root end (10) and a transition region (11), and wherein the length (L) of the inner blade section (1A)_1A) Including up to 90% of the total blade length (L).

12. Wind turbine rotor blade according to claim 10 or claim 11, wherein the length (L) of the inner blade section (1A) is_1A) Including at least 10% of the total blade length (L).

13. A wind turbine rotor blade according to any of claims 10-12, wherein the rotor blade (1) has a length (L) of at least 70 meters, and wherein the inner blade section (1A) has a mass in the range of 700 kg/m in the transition region (11).

14. A wind turbine rotor blade according to claim 13, wherein the outer blade section (12) has a mass in the range of 50 kg/m.

Technical Field

A method of manufacturing a wind turbine rotor blade is described. The invention also describes a wind turbine rotor blade.

Background

Wind turbine rotor blades are typically made by infusion molding of composite materials. There are various different kinds of moulds that can be used for manufacturing blades, and each kind has advantages and disadvantages.

in the open mold technique, the mold comprises two halves, wherein each mold half extends from a root to a tip. The composite lay-up (layup) is completed for each blade half and subsequently the mould is subjected to a vacuum bagging process before the resin infusion and curing steps are performed. The cured blade halves are then glued together along their outer edges.

In the closed mold casting technique, a mandrel or other element is used to help shape the blade, the composite lay-up is completed for the entire blade, and then the mold is closed before the resin infusion and curing steps are performed.

Moulding large one-piece wind turbine blades is time consuming and requires a correspondingly large footprint for the mould. A lot of time is needed to prepare the thicker regions in the inboard part of the blade, since here the chord length is largest ("inboard" part comprises the blade root end and the transition section to the airfoil). Often, multiple layers of glass fiber mats need to be built in the inboard blade area in order to achieve the desired quality (mass). For example, in the widest part of the inner region of a 75 meter rotor blade, the desired mass may be about 700 kg/meter. Thus, most of the time allocated for preparing the layup is spent on the inner region.

thus, the time taken to prepare the blade for molding is a considerable cost factor. Various ways of reducing the preparation time are known, for example it is known to pre-manufacture the beam (the main load-bearing element placed inside the blade) and to put the prefabricated part into the mould. This time saving technique can be used in both open and closed mold processes.

Floor space is also a cost factor. However, the size of the moulds used to manufacture long one-piece rotor blades (in the range of 70 metres or more) means that the floor space costs are typically high.

Disclosure of Invention

It is therefore an object of the present invention to provide an improved method of manufacturing a rotor blade which overcomes the problems outlined above.

This object is achieved by a method of manufacturing a wind turbine rotor blade according to claim 1 and by a wind turbine rotor blade according to claim 10.

The inventive method is for manufacturing wind turbine rotor blades each comprising an inner (inboard) section and a separately manufactured outer (outboard) section. The inboard blade section includes a root end and a transition region, and is manufactured using a first casting process. The outboard blade section includes an airfoil region and is manufactured using a second casting process. The second casting process is different from the first casting process, wherein this is understood to mean that the two casting processes require different moulding tools and different moulding techniques. Thus, the combination provides more freedom for blade manufacture, as the method of the invention can make best use of the advantages of both casting processes.

The invention is based on the insight that: if the blade is divided into sections according to the time required for manufacturing the different sections and if different casting techniques are used for manufacturing the time consuming sections and the less time consuming sections, a lot of time can be saved. By manufacturing the time consuming sections separately from the less time consuming sections, the process flow can be optimized. For example, it is known that more time is required for material processing on the inboard portion of the blade to achieve the required thickness. Thus, the manufacture of the inboard blade section or the blade root section is time consuming, whereas the manufacture of the outboard blade section is significantly less time consuming. In the prior art, regardless of the molding technique used to cast a complete, one-piece rotor blade, the layup of the outboard blade sections is typically completed well before the layup of the inboard blade sections is completed, but the pour molding and curing steps must wait until the root and transition layup is completed. Thus, in prior art methods, floor space and resources are effectively wasted due to the length of time required to complete layup of the root and transition regions.

Although it has been proposed to manufacture the rotor blade as a "split blade" in two or more parts, this is only to facilitate transportation and installation of the wind turbine, for example by: selecting one type of root section, selecting one of several possible airfoils or tip sections, transporting the sections to an installation site, and installing the tip section to the root section. However, such methods do not focus on manufacturing the root and tip sections using different types of casting processes, such that the prior art two-piece blade does not contribute any to the increase in manufacturing efficiency or the reduction in manufacturing costs.

According to the invention, a wind turbine rotor blade will comprise an outer blade section manufactured using a first casting process, and an inner blade section manufactured using a second, different casting process.

Particularly advantageous embodiments and features of the invention are given by the dependent claims, as disclosed in the following description. Features from different claim categories may be optionally combined to give further embodiments not described herein.

In the following, without limiting the invention in any way, it may be assumed that each rotor blade has a length in the range of 70 meters or more. An "inboard" blade section is understood to include the blade root end as well as a transition section in which the blade root end with its circular cross section transitions into the airfoil shape of the rest of the rotor blade. The inboard blade section includes a blade root end and preferably extends to at least 30% of the total blade length. The inboard blade section comprises a larger portion of the airfoil portion of the rotor blade.

the method according to the invention is particularly suitable for the manufacture of large rotor blades, since these are very large in the thickest region. Preferably, the rotor blade manufactured using the method of the invention has a length of at least 70 meters. The (usually) rounded root-end section smoothly transitions to the airfoil shape in the transition region, and this transition is usually rather short. The transition region is the region with the largest chord length. Therefore, the walls of the rotor blade must be relatively thick in this region in order to withstand the loads during operation. In a preferred embodiment of the invention, the inner blade section of the rotor blade has a mass in the range of 700 kg/m in the transition region. In contrast, the outboard blade section, which has its gradually narrowing airfoil shape, is lighter. In a preferred embodiment of the invention, the outer blade section has a mass in the range of 50 kg/m.

In a preferred embodiment of the invention, the first casting process is an open mold casting process, wherein two inner mold halves are used to cast two inner segment halves, respectively. After the injection molding and curing, the medial halves are then glued together. Preparing the inboard or root section in this manner, independently of and separately from the outboard airfoil section, has the advantage of not wasting layup time. In other words, when time is spent to achieve the desired thickness at the root and transition portions of the blade, no completed airfoil layup is waiting.

When the inboard section is manufactured using an open-die casting technique, the outboard or airfoil section is molded using a closed-die casting process in which the entire layup is completed in a first outboard mold half. Once the lay-up is complete, a second outside mold half is placed over the lay-up to close the mold. A step of injection molding is performed to complete the casting process. Thus, a closed mold casting process is used to manufacture the entire outboard section or airfoil. An advantage of preparing the outboard section in this manner is that the casting technique allows for the high surface quality required of the airfoil portion of the rotor blade. The layup is also relatively fast to complete because the composite material is also relatively thin towards the tip end of the blade.

the method of the invention can significantly reduce the manufacturing costs for a single blade by skillfully arranging the casting stages. In a preferred embodiment of the invention, the method comprises the steps of: arranging two successive workflow stages; producing three lateral sections and one medial section during one workflow stage; and manufacturing the two inner sections during another workflow stage.

Then, the three inboard sections may be connected to the three outboard sections to complete the three rotor blades. To complete these three rotor blades, only two molds are required to prepare the three inboard sections.

As mentioned above, the manufacture of the inboard section is typically significantly more time consuming than the manufacture of the outboard section. Thus, in a particularly preferred embodiment of the invention, the duration of the workflow stage is determined based on the time required for manufacturing the inboard blade section. The duration of the workflow stage may be determined by measuring the time it takes to prepare the inner blade section using a first casting process, for example a mould casting process. Any associated costs, such as personnel costs, floor space costs, and the like, may also be determined. Based on the determined cost and timing, the rotor blade manufacturer may determine the most cost-effective way to manufacture a certain number of rotor blades. For example, if a rotor blade is to be manufactured for a wind farm having 100 wind turbines, using the method of the present invention, a manufacturer may first determine the optimum number of inside blade sections that can be manufactured in a single workflow stage and the optimum number of outside blade sections that can be manufactured in a single workflow stage, and may provide an appropriate number of moulds. The arrangement of the workflow stages for the manufacture of the separate medial and lateral sections can then be done in the framework of an optimized process flow.

these medial and lateral sections may be coupled at some appropriate stage. In a preferred embodiment of the invention, the blade sections are joined after the two casting processes are completed. For example, three completed inboard sections may be coupled to three completed outboard sections at some stage after the three outboard sections have been manufactured. Alternatively, the blade sections are joined during one of two casting processes.

For this purpose, a suitable connector interface is provided. This may be achieved by preparing each of the medial and lateral sections to include a connector interface portion. The connector interface portion may be a dedicated component that is somehow attached to the medial/lateral section during casting. Alternatively, in a preferred embodiment of the invention, the connector interface portion is formed as part of a load bearing element or beam embedded in the blade section during casting. For example, when casting the inboard section, the beam can extend beyond the non-root end of the inboard section by an amount. When casting the outboard section, a corresponding "negative shape" may be prepared so that the inboard and outboard sections may be simply assembled together. This type of connector interface may be used to connect an already completed outboard section to an inboard section during casting of the inboard section. Also, this type of connector interface may be used to connect an already completed outboard section to an already completed inboard section.

Drawings

Other objects and features of the present invention will become apparent from the following detailed descriptions considered in conjunction with the accompanying drawings. It is to be understood, however, that the drawings are designed solely for the purposes of illustration and not as a definition of the limits of the invention.

FIG. 1 illustrates an embodiment of a wind turbine rotor blade manufactured using the method of the present invention;

FIG. 2 shows two sections of the blade of FIG. 1;

FIG. 3 illustrates various stages of an embodiment of a method of the present invention;

FIG. 4 illustrates a step of a first casting process;

Fig. 5 shows a step of the second casting process.

In the drawings, like reference numerals refer to like elements throughout. The objects in the drawings are not necessarily to scale.

Detailed Description

Fig. 1 shows an embodiment of a wind turbine rotor blade 1 manufactured using the method of the invention. The two sections 1A, 1B are manufactured using different casting processes and joined together to form a seamless connection. Fig. 2 shows the blade sections 1A, 1B in the way they would appear if each blade section 1A, 1B were manufactured separately.

The rotor blade 1 comprises a root end 10, a transition region 11 and an airfoil 12. The transition region 11 is shaped to form a smooth transition between the (usually) rounded root end 10 and the airfoil. The blade 1 is assembled from two sections 1A, 1B, as indicated by the dashed lines in fig. 1, for example by means of the interface 14 shown in fig. 2. The inboard blade section 1A comprises a root end 10, a transition region 11 and a portion of an airfoil 12. The outboard blade section 1B includes the remainder of the airfoil 12.

The blade 1 may have a length L of 70 meters or more. The blade 1 is thickest in the transition region, firstly because this region is the widest part of the blade, and secondly because this part of the blade is subjected to the highest loads during operation. The thickest part of the blade 1 also usually coincides with the longest chord, as in the largest airfoil shape C in FIG. 2_maxAs shown. Length L of inner section 1A_1AMay comprise at least 1% of the total blade length L, and preferably comprises at least 10% of the total blade length L, more preferably comprises at least 15% of the total blade length L, and most preferably comprises at least 20% of the total blade length L. Length L of inner section 1A_1AMay comprise up to 90% of the total blade length L, more preferably comprises up to 50-80% of the total blade length L, and most preferably comprises up to 40% of the total blade length L. Length L of outer section 1B_1BMaking up the remainder of the total blade length L. Thus, the preferred length L of the inner section 1A expressed as a percentage of the total blade length L_1AIn the range of 10% -90%, more preferably in the range of 15% -80%, more preferably in the range of 20% -60%, more preferably in the range of 20% -50%, and most preferably in the range of 20% -40%.

Fig. 3 illustrates stages S1, S2, S3 of an embodiment of the method of the present invention. Here, two casting workflow stages S1, S2 have been arranged, for example to manufacture rotor blades for wind turbines each requiring three rotor blades. In a first workflow stage S1, a multiple of three outboard sections are manufactured, as well as an equal multiple of inboard sections. For example, six lateral sections and two medial sections are simultaneously manufactured in workflow stage S1. In a subsequent process step S2, the remaining inner section is produced. Using the example above, the remaining four inboard segments were manufactured. In the third workflow stage S3, six inboard sections are coupled to six outboard sections. In the case of performing the method as described herein, only a total of four inner section moulds are required for the manufacture of six blades.

if the blade sections 1A, 1B are manufactured separately, the third workflow stage S3 may be independent in time from the first and second workflow stages S1, S2. Alternatively, if the previously manufactured outboard blade section 1A was coupled to the inboard section prior to casting and curing the inboard section 1B, the third workflow stage S3 may be temporally related to the second workflow stage S2.

Fig. 4 is a schematic view of the process steps involved in the first casting process P1. This technique may also be referred to as a "butterfly" technique and is particularly suited for manufacturing the inboard blade section as shown herein. In step P1.1, the mold halves 40A, 40B are produced and laid up to produce the two segment halves 1A _1, 1A _ 2. In step P1.2, the segment halves 1A _1, 1A _2 are cast and cured, respectively (typically simultaneously). In step P1.3, the load-bearing spar or beam 41 is arranged inside and the mould halves 40A, 40B are joined in step P1.4, and subsequently the cured segment halves 1A _1, 1A _2 are glued together in step P1.5. Once the glue has cured, the finished part, in this case the inner blade section 1A, may be removed from the mould 40A, 40B.

Fig. 5 is a schematic view of the process steps involved in the second casting process P2. This technique may also be referred to as "integral" technique and is particularly suitable for manufacturing outboard blade sections 1B as shown herein. In step P2.1, the lower mold half 50A is prepared, and in step P2.2, the lay-up 1B _1 of the lower half is completed. A mandrel 51 or similar element is placed in position in step P2.3 to assist in forming the upper half. Then, the upper half of the ply 1B _2 is finished in step P2.4. In a subsequent step P2.5, the upper mould half 50B is put in place and the entire blade section 1B is cast and cured in step P2.6. Typically, the mandrel is removed at this point.

The outer blade section 1B may then be connected to the inner blade section 1A manufactured as explained in fig. 5 above. Alternatively, the outer blade section 1B may be connected to the inner blade section 1A before the inner blade section 1B is cured, e.g. at some point between the above-mentioned steps P1.4 and P1.5.

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.

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