A crown-type wind turbine foundation structure with replaceable anchor bolts

Abstract

The present invention provides a crown-type wind turbine foundation structure with replaceable anchor bolts, comprising a main body foundation, a crown conversion component, prestressed anchor cables and a prestressed anchor cage. The crown conversion component adopts prefabricated movable components to transfer the load of the steel tower to the main body foundation, and is connected to the main body foundation by multiple prestressed anchor cables. The crown conversion component can be prefabricated and replaced according to the anchor bolt model. The main body foundation is a "concave"-shaped structure with a hollow middle, and the crown conversion component is an inverted "convex"-shaped structure with a protruding bottom and a hollow middle, and the protruding part is inserted into the hollow area of ​​the main body foundation. This foundation form effectively solves the problem of the difficulty in replacing the anchor bolts of the wind turbine foundation, realizes the reuse of the original wind turbine foundation during the wind turbine capacity expansion and transformation process, reduces the cost and is simple and convenient to construct.

Description

Technical Field

[0001] The present invention belongs to the technical field of new energy engineering, and in particular relates to a crown-type wind turbine foundation structure with replaceable anchor bolts. Background Art

[0002] With the rapid development of wind power technology, wind turbines with larger single-unit capacities are constantly being introduced. However, wind power generation also faces the increasing scarcity of land resources and high-quality wind resources. The design life of a wind turbine is 20 years, while the land and wind turbine foundations are designed for a lifespan of 50 years. Therefore, to rationally utilize resources and improve power generation efficiency, the earliest wind power projects have been undergoing large-scale capacity expansion and renovation.

[0003] As wind turbine installed capacity increases, the load transferred to the foundation increases, and the number and strength of anchor bolts connected to the foundation also change. To maximize the use of existing wind turbine foundations, various methods have been developed to strengthen wind turbine foundations to withstand greater loads, such as adding concrete counterweights and diagonal bracing structures.

[0004] The traditional wind turbine foundation structure in the existing technology includes a wind turbine foundation and a steel tower set on the wind turbine foundation through a prestressed anchor cage. Since the wind turbine foundation and the prestressed anchor cage are formed as one piece, the anchor connector cannot be replaced. Therefore, if the anchor cage of the increased capacity wind turbine changes, the original foundation still needs to be completely removed. Summary of the Invention

[0005] In view of the defects of the existing technology, the present invention provides a crown-type wind turbine foundation structure with replaceable anchor bolts, which adopts prefabricated movable parts to realize the rapid replacement of the anchor bolt cage, so that the original foundation can be reused to the greatest extent.

[0006] The technical solution adopted by the present invention is as follows: a top crown type wind turbine foundation structure with replaceable anchor bolts, including a wind turbine foundation and a prestressed anchor cage. The wind turbine foundation consists of a main foundation and a top crown conversion component. The main foundation is a "concave" structure with a hollow middle. The top crown conversion component is an inverted "convex" structure with a protruding bottom and a hollow middle. The protruding part is inserted into the hollow area of ​​the main foundation. The top crown conversion component and the main foundation are fixedly connected by multiple prestressed anchor cables to form a detachable integrated structure. The steel tower is fixed to the top of the top crown conversion component through the prestressed anchor cage.

[0007] The hollow part of the main body foundation is "Y"-shaped, and the angle between the hollow inner wall and the upper surface of the main body foundation is not less than 105°, which reduces the stress concentration between the top crown conversion component and the main body foundation during force transmission.

[0008] The interface between the crown conversion component and the main body foundation is filled with cement base slurry or epoxy material to ensure a tight fit.

[0009] The bottom of the main body foundation is provided with a small room for people to go down and provide operating space for the inspection and replacement of prestressed anchor cables and prestressed anchor bolt cages.

[0010] The inner wall diameter of the lower chamber foundation is larger than the arrangement diameter of the prestressed anchor cable.

[0011] The main body foundation and the top crown conversion component are provided with steel casings that pass through the steel casings, and the prestressed anchor cables are fixed after passing through the steel casings.

[0012] The thickness of the crown conversion component inserted into the main body foundation is greater than the height of the ramp of the main body foundation.

[0013] The lower surface of the crown conversion component is completely in contact with the upper surface and inner wall of the main body foundation, and the diameter of the top plate of the crown conversion component is equal to the diameter of the upper surface of the main body foundation.

[0014] The advantages and technical effects of this invention include the use of prefabricated movable components to achieve replaceable anchor cages. Adjustment of the movable components' height and inner diameter increases the foundation weight to withstand the loads of wind turbine expansion and renovation. This foundation structure offers a rational design, simple construction, and strong adaptability. This allows for the replacement of anchor cages, maximizing the reuse of the existing foundation during wind turbine expansion and renovation. This effectively addresses the difficulty of replacing anchor bolts in wind turbine foundations, enabling the reuse of existing foundations during wind turbine expansion and renovation, reducing construction costs and simplifying and facilitating construction. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 A longitudinal cross-sectional view of a crown-type wind turbine foundation with replaceable anchor bolts provided by the present invention;

[0016] Figure 2 A top view of a crown-type wind turbine foundation with replaceable anchor bolts provided by the present invention;

[0017] Figure 3 This is a detailed structural diagram of the prestressed anchor cable provided by the present invention.

[0018] Figure 1: Main foundation; 2: Top crown conversion component; 3: Prestressed anchor cable; 4: Prestressed anchor cage; 5: Steel tower; 6: Lower manhole; 7: Steel casing; 8: Lower anchor plate support column; 31: Steel strand; 32: Steel casing; 33: Anchor plate; 34: Anchor; 35: Anti-corrosion sleeve; 36: Concrete protective cap DETAILED DESCRIPTION

[0019] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0020] In the description of the present invention, it should be noted that the terms "upper", "middle", "lower", "inside", "outside", "both sides", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings. They are only simplified descriptions for the convenience of describing the present invention, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they cannot be understood as limitations on the present invention.

[0021] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "installed," "provided with," "connected," etc., should be understood in a broad sense. For example, "connected" may refer to a fixed connection, a detachable connection, or an integral connection; it may refer to a mechanical connection or an electrical connection; it may refer to a direct connection or an indirect connection through an intermediate medium; it may refer to internal communication between two components. Those skilled in the art will be able to understand the specific meanings of the above terms in the present invention based on the specific circumstances.

[0022] like Figure 1-3 As shown, the crown-type wind turbine foundation structure with replaceable anchor bolts of the present invention includes a wind turbine foundation and a prestressed anchor cage. The wind turbine foundation consists of a main foundation 1 and a crown conversion component 2. The main foundation 1 is a "concave"-shaped structure with a hollow middle. The crown conversion component 2 is an inverted "convex"-shaped structure with a protruding bottom and a hollow middle. The protruding part is inserted into the hollow area of ​​the main foundation 1. The crown conversion component 2 and the main foundation 1 are fixedly connected by multiple prestressed anchor cables 3 to form a detachable integrated structure. The steel tower 5 is fixed to the top of the crown conversion component 2 through the prestressed anchor cage 4.

[0023] Furthermore, the hollow portion of the main foundation 1 is "Y"-shaped, and the angle between the hollow inner wall and the upper surface of the main foundation is not less than 105°, thereby reducing stress concentration between the top crown conversion component and the main foundation during force transmission.

[0024] Furthermore, the interface between the crown conversion component 2 and the main foundation 1 is filled with cement base slurry or epoxy material to ensure a close fit.

[0025] Furthermore, the bottom of the main foundation 1 is provided with a manhole 6 which provides an operating space for the inspection and replacement of the prestressed anchor cables and prestressed anchor bolt cages.

[0026] Furthermore, the diameter of the inner wall of the lower chamber 6 is larger than the arrangement diameter of the prestressed anchor cable 3 .

[0027] Furthermore, a steel casing 32 passing through the main body foundation 1 and the crown conversion component 2 is arranged, and the prestressed anchor cable 3 is fixed after passing through the steel casing 32 .

[0028] Furthermore, the thickness of the crown conversion component 2 inserted into the main body foundation 1 is greater than the height of the ramp of the main body foundation 1 .

[0029] Furthermore, the lower surface of the crown conversion component 2 is completely in contact with the upper surface and inner wall of the main body foundation 1 , and the top plate diameter of the crown conversion component 2 is equal to the upper surface diameter of the main body foundation 1 .

[0030] The following details are provided:

[0031] The top crown type wind turbine foundation structure with replaceable anchor bolts of the present invention includes a main foundation 1, a top crown conversion component 2, a prestressed anchor cable 3 and a prestressed anchor cage 4; the top crown conversion component 2 is a replaceable and prefabricated movable component, which is located between the tower 5 and the main foundation 1 and is used to transfer the wind turbine load; it is fixedly connected to the steel tower 5 through the prestressed anchor cage 4, and then fixedly connected to the main foundation 1 through multiple prestressed anchor cables 3, and the foundation load is first transferred to the top crown conversion component 2 through the anchor cage 4, and then transferred to the main foundation 1 through the prestressed anchor cables 3, forming an overall force.

[0032] In order to enhance the integrity between the top crown conversion component 2 and the main foundation 1, the main foundation 1 is a "concave"-shaped structure with a hollow middle, and the top crown conversion component 2 is an inverted "convex"-shaped structure with a protruding bottom and a hollow middle, and the protruding part is inserted into the hollow area of ​​the main foundation 1; the interface can be partially filled with cement base slurry or epoxy material to ensure a close fit and further enhance the integrity of the foundation.

[0033] In this embodiment, the primary loads borne by the wind turbine foundation are vertical forces and bending moments, resulting in stress concentration between the crown conversion component 2 and the main foundation 1. To minimize stress concentration on the contact surface, a chamfered R angle can be provided to smooth the shape change of the contact surface and reduce stress concentration. Therefore, the hollow portion of the main foundation is Y-shaped, meaning the angle between the hollow inner wall and the upper surface of the main foundation is no less than 105°. Due to the characteristics of the anchor cage and prestressed anchor cables transmitting force along the upper and lower tightening surfaces, the thickness of the crown conversion component 2 inserted into the main foundation 1 is greater than the height of the ramp of the main foundation 1, allowing for better force transmission to the lower base plate. Under the action of the wind turbine load, the tensile stress is primarily borne by the prestressed anchor cables 3, while the compressive stress is primarily transmitted to the foundation by the integral foundation.

[0034] In this embodiment, the main foundation 1 and the top crown conversion component 2 are provided with steel casings 32 in the height direction through which 16-36 prestressed steel strands 31 pass, and steel anchor plates 33 and anchors 34 are provided at both ends. The foundation is tightly connected by applying a pre-tightening force, and anti-corrosion sleeves 35 and concrete protective sleeves 36 are added at the anchors to prevent corrosion or damage of the prestressed anchor cables.

[0035] In this embodiment, a 1m high manhole cover 6 is provided below the main foundation 1. The inner wall diameter of the foundation of the manhole cover 6 is larger than the arrangement diameter of the prestressed anchor cable 3, mainly providing an operating space for the inspection and replacement of the prestressed anchor cable 3 and the prestressed anchor bolt cage 4. The bottom plate and the manhole cover 6 can be cast separately, and a water-stop steel plate 7 needs to be provided on the contact surface to prevent groundwater from seeping in.

[0036] In this embodiment, when the wind turbine is expanded and modified, the top crown conversion component 2 can be prefabricated and replaced according to the anchor cage model of the expanded and modified wind turbine. The top plate diameter of the top crown conversion component 2 is equal to the upper surface diameter of the main foundation 1. The top plate thickness of the top crown conversion component 2 tightened by the prestressed anchor cable 3 is increased by 0.5m to increase the foundation counterweight and realize the reuse of the main foundation and prestressed anchor cable.

[0037] In this embodiment, the inner wall diameter of the main foundation 1 can be determined according to the size development of the anchor cage in recent years, and a certain capacity expansion space is reserved for the replacement of the anchor bolts of the expected increased capacity wind turbine.

[0038] When the structure of the present invention is used, the construction method for replacing anchor bolts during wind turbine capacity expansion and reconstruction is as follows:

[0039] (1) Remove and recover the original prestressed anchor cage 4 and prestressed anchor cable 3 in sequence, use an electric drill or electric hammer to drill holes at the contact surface between the main foundation 1 and the crown conversion component 2, increase the foundation detachment surface without damaging the main foundation 1, and then use a crane to lift the crown conversion component 2 and perform auxiliary clearing and removal.

[0040] (2) The crown conversion component 2 is prefabricated again according to the anchor bolt model of the increased capacity wind turbine. It can be prefabricated upside down together with the anchor bolt cage in a processing plant or on a foundation vacant land, and a steel casing 32 is embedded in the foundation.

[0041] (3) Clean and level the surface of the main foundation 1, and use C40 grouting to repair the damaged areas to ensure the flatness of the contact surface.

[0042] (4) The crown conversion component 2 is hoisted and positioned to the top surface of the main foundation so that the crown conversion component 2 and the steel casing on the main foundation 1 are concentric, and cement base slurry or epoxy material is sprayed and grouted locally on the contact surface.

[0043] (5) Level and install the anchor plate 33, pass the steel strand 31 of the prestressed cable, put on the anchor 34, tension the steel strand 31 to apply preload, and then cast a C20 protective cap on the top of the anchor cable.

[0044] The present invention is applicable to current wind power projects and is intended only to illustrate the technical concepts and features of the present invention, but is not limited to current hollow angles, material grades, prestressed anchor cables, prefabricated components, construction tools, etc. Its purpose is to enable those skilled in the art to understand the contents of the present invention and implement them accordingly. This embodiment alone is not intended to limit the scope of the present invention. In other words, any equivalent changes or modifications made to the spirit disclosed by the present invention still fall within the scope of the present invention.

Claims

1. A crown-type wind turbine foundation structure with replaceable anchor bolts, comprising a wind turbine foundation and a prestressed anchor bolt cage, characterized in that: The wind turbine foundation is composed of a main foundation (1) and a top crown conversion component (2). The main foundation (1) is a hollow "concave"-shaped structure, and the top crown conversion component (2) is an inverted "convex"-shaped structure with a protruding bottom and a hollow center. The protruding part is inserted into the hollow area of ​​the main foundation (1). The top crown conversion component (2) and the main foundation (1) are fixedly connected by multiple prestressed anchor cables (3) to form a detachable integrated structure. The steel tower (5) is fixedly connected to the top of the top crown conversion component (2) by a prestressed anchor cage (4); the hollow part of the main foundation (1) is in a "Y" shape, and the hollow interior is The angle between the wall and the upper surface of the main body foundation is not less than 105°, thereby reducing the stress concentration between the crown conversion component and the main body foundation during the force transmission process; the interface between the crown conversion component (2) and the main body foundation (1) is filled with cement base slurry or epoxy material to ensure a tight fit; the thickness of the crown conversion component (2) inserted into the main body foundation (1) is greater than the height of the ramp of the main body foundation (1); the lower surface of the crown conversion component (2) is completely in contact with the upper surface and inner wall of the main body foundation (1), and the top plate diameter of the crown conversion component (2) is equal to the upper surface diameter of the main body foundation (1).

2. The crown-type wind turbine foundation structure with replaceable anchor bolts according to claim 1, characterized in that: The bottom of the main foundation (1) is provided with a small manhole (6) that provides an operating space for the inspection and replacement of the prestressed anchor cables and prestressed anchor bolt cages.

3. The crown-type wind turbine foundation structure with replaceable anchor bolts according to claim 2 is characterized in that: The inner wall diameter of the foundation of the lower chamber (6) is larger than the arrangement diameter of the prestressed anchor cable (3).

4. The crown-type wind turbine foundation structure with replaceable anchor bolts according to claim 1 is characterized in that: A steel casing (32) that passes through the main body foundation (1) and the top crown conversion component (2) is arranged, and the prestressed anchor cable (3) is fixed after passing through the steel casing (32).

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