Wind driven generator blade lightning protection device and wind driven generator set

Abstract

The invention relates to the technical field of wind driven generator lightning protection, and discloses a wind driven generator blade lightning protection device and a wind driven generator set. Due to the fact that the blade tip part is prone to being struck by lightning, the lightning arrester is arranged on the blade tip part, the lightning arrester and the electric heating piece are arranged in a spaced mode, the grounding down lead is connected to the lightning arrester, efficient lightning guiding can be conducted by arranging the lightning arrester on the blade tip part, and when the blade tip part is struck by lightning, the blade tip part is prevented from being struck by lightning. Lightning current can be rapidly introduced into the grounding down lead channel through the lightning arrester, the lightning current is released, and the fan blade is prevented from being damaged by lightning stroke. Similarly, because the electric heating element is easy to attract lightning stroke, the lightning protection metal layer on the surface of the electric heating element is connected with another grounding downlead, and when the electric heating element is struck by lightning, lightning current can be rapidly introduced into a grounding downlead channel through the lightning protection metal layer to release the lightning current, so that the electric heating element is prevented from being damaged by the lightning stroke, and the service life of the electric heating element is prolonged. And heating and ice melting of the electric heating piece on the fan blade are influenced.

Description

Technical Field

[0001] The invention belongs to the technical field of lightning protection for wind turbine generators, and in particular relates to a lightning protection device for wind turbine generator blades and a wind turbine generator set. Background Art

[0002] Electric heating ice melting is to pre-embed electric heating elements on the surface of wind turbine blades to heat and melt ice. Electric heating ice melting can be performed by energizing the electric heating elements, but heating elements such as resistance wires will cause a surge in the risk of lightning strikes at the carbon fiber laying position of wind turbine blades, reducing the safe operation level of the blades. At the same time, according to the on-site operation of wind farms, more than 95% of the lightning fault points of ordinary blades are mainly distributed within 5m of the blade tip. The existing lightning protection devices generally have the following two types: one is a blade lightning protection device using a lightning rod plus a grounding down conductor. A lightning rod is installed on the blade to guide lightning to hit the lightning rod and lead it to the ground through the grounding down conductor. However, the device is still a distance away from the tip of the blade. When lightning strikes at the tip of the blade, the lightning current cannot be quickly introduced into the grounding wire, resulting in the tip of the blade being broken down and damaged, and it is impossible to prevent the laying part of the electric heating element of the blade from being damaged by lightning; the other uses a guide bar as a lightning protection device for wind turbine blades. When lightning strikes, the air above the guide bar is broken down, and the lightning current enters the grounding down conductor along the broken air, which plays a role in lightning protection. However, the existing guide strips have limited lightning-attracting effects, making it difficult to effectively block lightning. In addition, the guide strips have insufficient current-carrying capacity and are damaged by a 60kA lightning current, resulting in frequent lightning damage accidents on wind turbine blades. Summary of the invention

[0003] The purpose of the present invention is to provide a wind turbine blade lightning protection device and a wind turbine generator set, so as to solve the technical problem that the wind turbine blade lightning protection effect is poor in the prior art.

[0004] In order to achieve the above object, the present invention provides a lightning protection device for wind turbine blades, the lightning protection device for wind turbine blades comprising:

[0005] A fan blade comprises a blade body and a blade tip portion located at the end of the blade body;

[0006] An electric heating element is arranged outside the blade body and is used to heat the blade body to melt ice, and the surface of the electric heating element is covered with a lightning protection metal layer;

[0007] A lightning receptor is arranged on the blade tip and spaced apart from the electric heating element;

[0008] The grounding assembly comprises two grounding down conductors for grounding, one end of one of the grounding down conductors is connected to the lightning arrester, and the other grounding down conductor is welded to the lightning protection metal layer.

[0009] In an embodiment of the present invention, a metal protective sleeve is provided on the outer peripheral sleeve of the blade tip, and a plurality of annular grooves are opened along the circumferential direction on the outer peripheral wall of the blade tip. The plurality of annular grooves are arranged at intervals along the height direction of the blade body, and the annular grooves are filled with insulating glue to bond the metal protective sleeve to the blade tip.

[0010] In an embodiment of the present invention, a lightning rod hole is provided on the blade tip, and a mounting hole is provided on the metal protective sleeve corresponding to the lightning rod hole. The lightning rod passes through the mounting hole and the lightning rod hole in sequence and is electrically connected to the metal protective sleeve.

[0011] In an embodiment of the present invention, a fixing through hole is also opened on the blade tip, and a locking hole is opened on the metal protective cover corresponding to the fixing through hole. The wind turbine blade lightning protection device also includes a fastener, which passes through the locking hole and the fixing through hole in sequence and is connected to the blade body.

[0012] In an embodiment of the present invention, the fastener includes a sleeve and two bolts axially oppositely arranged. The sleeve is embedded in the fixing through hole and fastened to the inner wall of the fixing through hole. Both bolts are pan head structures. The screw rod of the bolt is placed in the sleeve and threadedly connected to the sleeve.

[0013] In an embodiment of the present invention, the thickness of the metal protective sleeve and the lightning protection metal layer are both greater than or equal to 0.5 mm and less than 1 mm.

[0014] In an embodiment of the present invention, the plurality of annular grooves are arranged at equal intervals, and the interval between any two adjacent annular grooves ranges from 15 mm to 25 mm.

[0015] In an embodiment of the present invention, the cross section of the annular groove is a V-shaped structure, the groove width of the annular groove is in the range of 2 mm to 4 mm, and the groove depth of the annular groove is in the range of 1 mm to 2 mm.

[0016] In an embodiment of the present invention, the metal protective sleeve and the lightning protection metal layer are both made of one of aluminum, copper or stainless steel.

[0017] In an embodiment of the present invention, a wind turbine generator set is provided, comprising the above-mentioned lightning protection device for wind turbine blades.

[0018] Through the above technical solution, the wind turbine blade lightning protection device and wind turbine generator set provided by the embodiments of the present invention have the following beneficial effects:

[0019] The lightning protection device for wind turbine blades in this embodiment includes a fan blade, an electric heating element, a lightning rod and a grounding assembly. The fan blade includes a blade body and a blade tip located at the end of the blade body. The electric heating element is arranged outside the blade body and is used to heat and melt ice on the blade body. The surface of the electric heating element is covered with a lightning protection metal layer. Since the blade tip is easily struck by lightning, the lightning rod in this embodiment is arranged on the blade tip and is spaced apart from the electric heating element. A grounding down conductor is connected to the lightning rod. By arranging the lightning rod at the blade tip, lightning can be efficiently attracted. When the blade tip is struck by lightning, the lightning current can be quickly introduced into the grounding down conductor channel through the lightning rod to release the lightning current and prevent the fan blade from being damaged by lightning. Similarly, since the electric heating element is also prone to attracting lightning strikes, this embodiment connects another grounding down conductor to the lightning protection metal layer on the surface of the electric heating element. When the electric heating element is struck by lightning, the lightning current can be quickly introduced into the grounding down conductor channel through the lightning protection metal layer to release the lightning current, thereby preventing the lightning strike from damaging the electric heating element and affecting the heating and ice melting of the fan blades by the electric heating element. At the same time, because the grounding down conductor is connected to the lightning protection metal layer, the lightning conduction area of ​​the fan blades is increased, reducing the damage to the fan blades by lightning, so that the fan blades can withstand a larger lightning current impact.

[0020] Other features and advantages of the embodiments of the present invention will be described in detail in the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The accompanying drawings are used to provide a further understanding of the embodiments of the present invention and constitute a part of the specification. Together with the following specific embodiments, they are used to explain the embodiments of the present invention, but do not constitute a limitation on the embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on the structures shown in these drawings without creative work. In the accompanying drawings:

[0022] Figure 1 It is a structural schematic diagram of a lightning protection device for wind turbine blades according to the present invention from one perspective;

[0023] Figure 2 It is a schematic structural diagram of the wind turbine blade lightning protection device according to the present invention from another perspective.

[0024] Description of Reference Numerals

[0025] 11 Blade body 5 Grounding down conductor

[0026] 12 Blade tip 6 Metal protective sleeve

[0027] 2 Electric heating element 7 Annular groove

[0028] 3 Lightning protection metal layer 8 Lightning connection hole

[0029] 4 Lightning terminal 9 Fasteners DETAILED DESCRIPTION

[0030] The specific implementation of the present invention is described in detail below in conjunction with the accompanying drawings. It should be understood that the specific implementation described here is only used to illustrate and explain the present invention, and is not used to limit the present invention.

[0031] The wind turbine blade lightning protection device and the wind turbine generator set according to the present invention are described below with reference to the accompanying drawings.

[0032] like Figure 1 and Figure 2 As shown, in this embodiment, a lightning protection device for wind turbine blades is proposed, and the lightning protection device for wind turbine blades includes a fan blade, an electric heating element 2, a lightning receptor 4 and a grounding assembly. The fan blade includes a blade body 11 and a blade tip 12 located at the end of the blade body 11. The electric heating element 2 is arranged outside the blade body 11 and is used to heat and melt ice on the blade body 11. The surface of the electric heating element 2 is covered with a lightning protection metal layer 3. The lightning receptor 4 is arranged on the blade tip 12 and is spaced apart from the electric heating element 2. The grounding assembly includes two grounding down conductors 5 for grounding, one end of which is connected to the lightning receptor 4, and the other grounding down conductor 5 is welded to the lightning protection metal layer 3. The welding point is also coated with anti-corrosion paint to prevent corrosion and welding at the welding point. Since the blade tip 12 is susceptible to lightning strikes, the lightning receptor 4 in this embodiment is arranged on the blade tip 12 and spaced apart from the electric heating element 2. A grounding down conductor 5 is connected to the lightning receptor 4. When the blade tip 12 is struck by lightning, the lightning current can be quickly introduced into the grounding down conductor channel through the lightning receptor 4 to release the lightning current. By arranging the lightning receptor 4 at the blade tip 12, lightning can be efficiently attracted to avoid damage to the fan blades by lightning strikes. Similarly, since the electric heating element 2 is also susceptible to lightning strikes, another grounding down conductor 5 is connected to the lightning protection metal layer 3 on the surface of the electric heating element 2 in this embodiment. When the electric heating element 2 is struck by lightning, the lightning current can be quickly introduced into the grounding down conductor channel on the fan blades through the lightning protection metal layer 3 to release the lightning current, thereby avoiding damage to the electric heating element 2 by lightning strikes and affecting the heating and ice melting of the fan blades by the electric heating element 2. At the same time, because the grounding down conductor 5 is connected to the lightning protection metal layer 3, the lightning conduction area of ​​the wind turbine blades is increased, the damage of lightning to the wind turbine blades is reduced, and the wind turbine blades can withstand a larger lightning current impact.

[0033] In addition, structural adhesive is arranged on the side of the electric heating element 2 facing the lightning protection metal layer 3, and the outer surface of the electric heating element 2 is coated with structural adhesive after grinding, so that the lightning protection metal layer 3 is fixed on the electric heating element 2 through the structural adhesive. In addition, the structural adhesive also has an isolation effect. For example, in this embodiment, the structural adhesive can be an insulating adhesive, which can effectively isolate the lightning protection metal layer 3 and the electric heating element 2, thereby preventing the lightning current from being transmitted to the electric heating element 2 after a lightning strike.

[0034] like Figure 1 As shown, in this embodiment, the outer periphery of the blade tip 12 is provided with a metal protective sleeve 6. The metal protective sleeve 6 serves as a protective shell, which can effectively protect the end of the wind turbine blade and prevent damage to the wind turbine blade caused by lightning strikes. In addition, a plurality of annular grooves 7 are provided on the outer peripheral wall of the blade tip 12 along the circumferential direction. The plurality of annular grooves 7 are arranged at intervals along the height direction of the blade body 11. The annular grooves 7 are filled with insulating glue, which maintains the bonding stability while having a good insulation effect, and can ensure that the metal protective sleeve 6 is stably bonded to the blade tip 12. The height direction is Figure 1 The up-down direction and the width direction are Figure 1 The left and right direction in .

[0035] like Figure 2 As shown, in this embodiment, a lightning through hole 8 is provided on the blade tip 12, and a mounting hole is provided on the metal protective sleeve 6 at a position corresponding to the lightning through hole 8, and the lightning receptor 4 sequentially passes through the mounting hole and the lightning through hole 8 and is electrically connected to the metal protective sleeve 6. By installing the lightning receptor 4 on the metal protective sleeve 6, if the metal protective sleeve 6 is struck by lightning, when the lightning current is transmitted to the metal protective sleeve 6, the current can be conducted to the ground by connecting the lightning receptor 4 to the grounding down conductor 5, thereby avoiding damage to the metal protective sleeve 6 caused by lightning striking the metal protective sleeve 6.

[0036] like Figure 2 As shown, in this embodiment, three fixing through holes are further provided on the blade tip 12, and a locking hole is provided at a corresponding position of each fixing through hole on the metal protective cover 6. The lightning protection device for wind turbine blades also includes a fastener 9, which passes through the locking hole and the fixing through hole in sequence and is connected to the blade body 11. The fastener 9 is arranged to further improve the stability of the installation of the wind turbine blade and the metal protective cover 6. The number of the fixing through holes can be adjusted according to actual needs.

[0037] like Figure 2As shown, in this embodiment, the fastener 9 includes a sleeve and two bolts arranged axially opposite to each other. The sleeve is embedded in the fixed through hole and is fastened to the inner wall of the fixed through hole. Both bolts are pan head structures. The screw rods of the bolts are placed in the sleeve and are threadedly connected to the sleeve. Among them, an internal thread is formed on the inner wall of the sleeve, and external threads matching the internal thread of the sleeve are formed on the screw rods of the two bolts. When assembling the fastener 9 into the fixed through hole, the sleeve is first embedded in the fixed through hole so that the sleeve and the blade tip 12 of the fan blade fit tightly, and then the bolts are inserted from both sides of the fixed through hole so that the two bolts are threadedly connected to the sleeve, and the sleeve is limited and fixed by the pan head structure on the bolt.

[0038] In this embodiment, the thickness of the metal protective sleeve 6 and the lightning protection metal layer 3 are both greater than or equal to 0.5 mm and less than 1 mm. The metal protective sleeve 6 and the lightning protection metal layer 3 are one of aluminum, copper or stainless steel. Among them, the thickness of the metal protective sleeve 6 and the lightning protection metal layer 3 in this embodiment is selected to be 0.7 mm, which has a good lightning protection effect and a low production cost. The material of the metal protective sleeve 6 and the lightning protection metal layer 3 is selected to be copper.

[0039] In this embodiment, a plurality of annular grooves 7 are arranged at equal intervals, and the spacing between any two adjacent annular grooves 7 ranges from 15 mm to 25 mm. The cross-section of the annular groove 7 is a V-shaped structure, which reduces the consumption of the insulating glue and can maintain a good bonding effect. The width of the annular groove 7 ranges from 2 mm to 4 mm, and the depth of the annular groove 7 ranges from 1 mm to 2 mm. Among them, the bonding effect is good after the insulating glue is filled when the annular groove 7 is opened to the following dimensions: the spacing between two adjacent annular grooves 7 is 20 mm, the width of the annular groove 7 is 3 mm, and the depth of the annular groove 7 is 1.5 mm.

[0040] In this embodiment, a wind turbine generator set is proposed, including the above-mentioned wind turbine generator blade lightning protection device. Since the wind turbine generator set adopts all the embodiments of the wind turbine generator blade lightning protection device, it also has all the beneficial effects brought by the wind turbine generator blade lightning protection device, which will not be described in detail here. The wind turbine equipped with the wind turbine generator blade lightning protection device in this embodiment can take into account the electric heating ice melting and lightning protection of the wind turbine blades. While meeting the electric heating of the wind turbine blades, it greatly reduces the risk of wind turbine blade icing shutdown and lightning damage. It improves the safe operation level of wind farms, increases the winter icing operation time of wind turbine blades, reduces the risk of power shortage caused by wind turbine blade icing shutdown, reduces the wind blade icing shutdown time, and enhances the safety and economy of wind turbine generator set operation and new energy consumption.

[0041] In addition, the wind turbine blade lightning protection device in this embodiment can not only be pre-installed before the wind turbine blades leave the factory, but can also be installed or modified on wind turbine blades that have been put into operation. This device is simple and convenient to install and has a significant lightning protection effect.

[0042] In the description of the present invention, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0043] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection, an electrical connection, or communication with each other; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0044] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0045] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. A lightning protection device for wind turbine blades, characterized in that: The wind turbine blade lightning protection device comprises: A fan blade comprises a blade body (11) and a blade tip (12) located at the end of the blade body (11); An electric heating element (2) is arranged outside the blade body (11) and is used to heat the blade body (11) to melt ice, and the surface of the electric heating element (2) is covered with a lightning protection metal layer (3); A lightning receptor (4) is arranged on the blade tip (12) and is spaced apart from the electric heating element (2); The grounding assembly comprises two grounding down conductors (5) for grounding, wherein one end of one of the grounding down conductors (5) is connected to the lightning receptor (4), and the other grounding down conductor (5) is welded to the lightning protection metal layer (3).

2. The wind turbine blade lightning protection device according to claim 1, characterized in that: The outer periphery of the blade tip (12) is provided with a metal protective sleeve (6), and a plurality of annular grooves (7) are provided on the outer peripheral wall of the blade tip (12) along the circumferential direction. The plurality of annular grooves (7) are arranged at intervals along the height direction of the blade body (11), and the annular grooves (7) are filled with insulating glue to bond the metal protective sleeve (6) to the blade tip (12).

3. The lightning protection device for wind turbine blades according to claim 2 is characterized in that: The blade tip (12) is provided with a lightning arrester hole (8), the metal protective sleeve (6) is provided with a mounting hole corresponding to the lightning arrester hole (8), and the lightning arrester (4) sequentially passes through the mounting hole and the lightning arrester hole (8) and is electrically connected to the metal protective sleeve (6).

4. The wind turbine blade lightning protection device according to claim 2, characterized in that: The blade tip (12) is also provided with a fixing through hole, the metal protective sleeve (6) is provided with a locking hole corresponding to the fixing through hole, and the wind turbine blade lightning protection device also includes a fastener (9), the fastener (9) sequentially passes through the locking hole and the fixing through hole and is connected to the blade body (11).

5. The lightning protection device for wind turbine blades according to claim 4 is characterized in that: The fastener (9) comprises a sleeve and two bolts arranged axially opposite to each other, the sleeve is embedded in the fixing through hole and is tightly connected to the inner wall of the fixing through hole, the two bolts are both pan head structures, and the screw rods of the bolts are placed in the sleeve and are threadedly connected to the sleeve.

6. The lightning protection device for wind turbine blades according to claim 2, characterized in that: The thickness of the metal protective sleeve (6) and the lightning protection metal layer (3) are both greater than or equal to 0.5 mm and less than 1 mm.

7. The lightning protection device for wind turbine blades according to claim 2, characterized in that: The plurality of annular grooves (7) are arranged at equal intervals, and the interval between any two adjacent annular grooves (7) ranges from 15 mm to 25 mm.

8. The lightning protection device for wind turbine blades according to claim 2, characterized in that: The cross section of the annular groove (7) is a V-shaped structure, the groove width of the annular groove (7) ranges from 2 mm to 4 mm, and the groove depth of the annular groove (7) ranges from 1 mm to 2 mm.

9. The lightning protection device for wind turbine blades according to any one of claims 2 to 8, characterized in that: The metal protective sleeve (6) and the lightning protection metal layer (3) are both made of one of aluminum, copper or stainless steel.

10. A wind turbine generator set, characterized in that: The invention comprises a lightning protection device for a wind turbine blade according to any one of claims 1 to 9.

Images