Top crown type fan foundation structure with replaceable anchor bolts

Abstract

The invention provides a top crown type wind turbine foundation structure with replaceable anchor bolts. The top crown type wind turbine foundation structure comprises a main body foundation, a top crown conversion part, a pre-stressed anchor cable and a pre-stressed anchor bolt cage. The top crown conversion component is a prefabricated movable component, transmits the load of a steel tower drum to the main body foundation, is connected with the main body foundation through a plurality of pre-stressed anchor cables, and can be prefabricated and replaced in a matched mode according to the type of anchor bolts. The main body foundation is of a concave structure with the hollow middle, the top crown conversion component is of an inverted convex structure with the bottom protruding and the hollow middle, and the protruding part is inserted into the hollow area of the main body foundation. The foundation form effectively solves the problem that the anchor bolts of the fan foundation are difficult to replace, the original fan foundation is recycled in the fan capacity increasing transformation process, the manufacturing cost is reduced, and construction is easy and convenient.

Description

Technical Field

[0001] The 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 generation technology, wind turbines with larger single-unit capacity are constantly being introduced, but wind power generation is also facing the problem of increasingly scarce land resources and excellent wind resources. The design service life of wind turbines is 20 years, while the design service life of land acquisition and wind turbine foundations is 50 years. Therefore, in order to rationally utilize resources and improve power generation efficiency, the earliest wind power projects have been undergoing capacity expansion and transformation on a large scale.

[0003] The increase in wind turbine installed capacity corresponds to an increase in the load transferred to the wind turbine foundation, and the number and strength of anchor bolts connected to the foundation also change. In order to maximize the use of the original wind turbine foundation, there are many ways to strengthen the wind turbine foundation so that the foundation can withstand greater loads, such as adding concrete counterweights and adding diagonal bracing support structures.

[0004] The conventional wind turbine foundation structure of the prior art includes a wind turbine foundation and a steel tower tube arranged on the wind turbine foundation through a prestressed anchor cage. Since the wind turbine foundation and the prestressed anchor cage are formed integrally, the anchor connector cannot be replaced. Therefore, if the anchor cage of the increased capacity wind turbine is changed, the original foundation still needs to be completely removed. Summary of the invention

[0005] In view of the defects of the prior art, the present invention provides a crown-type wind turbine foundation structure with replaceable anchor bolts, which adopts prefabricated movable parts to achieve 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" shaped structure with a hollow middle, the top crown conversion component 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, the top crown conversion component and the main foundation are fixedly connected by multiple prestressed anchor cables to form a detachable integrated structure, and 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 in a "Y" shape, and the angle between the hollow inner wall and the upper surface of the main body foundation is not less than 105°, thereby reducing the stress concentration between the top crown conversion component and the main body foundation during the force transmission process.

[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 arranged as a small manhole providing an operating space for the inspection and replacement of the 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 penetrate up and down, 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 ramp height 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 top plate diameter of the crown conversion component is equal to the upper surface diameter of the main body foundation.

[0014] The advantages and technical effects of the present invention are as follows: prefabricated movable parts are used to realize the replaceability of the anchor cage; and by adjusting the height and inner diameter of the movable parts, the foundation weight is increased to resist the load of the wind turbine during capacity expansion and transformation. It is a foundation form with reasonable design, simple construction and strong applicability, which realizes the replaceability of the anchor cage, so that the original foundation can be reused to the greatest extent during the process of wind turbine capacity expansion and transformation. It effectively solves the problem of difficulty in replacing the anchor bolts of the wind turbine foundation, realizes the reuse of the original wind turbine foundation during the process of wind turbine capacity expansion and transformation, reduces the cost and is simple and convenient to construct. 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 A detailed structural diagram of the prestressed anchor cable provided by the present invention.

[0018] In the figure, 1. main foundation; 2. crown conversion component; 3. prestressed anchor cable; 4. prestressed anchor bolt cage; 5. steel tower; 6. lower manhole; 7. steel casing; 8. lower anchor plate support column; 31. steel strand; 32. steel casing; 33. anchor pad; 34. anchor; 35. anti-corrosion sleeve; 36. concrete protective cap DETAILED DESCRIPTION

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

[0020] In the description of the present invention, it should be noted that the orientations or positional relationships indicated by terms such as “upper”, “middle”, “lower”, “inside”, “outside”, and “both sides” are based on the orientations or positional relationships shown in the accompanying drawings, and are only simplified descriptions for the convenience of describing the present invention, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0021] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "provided with", "connected", etc. should be understood in a broad sense. For example, "connected" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0022] like Figure 1-3 As shown, the top 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 top crown conversion component 2. The main foundation 1 is a "concave"-shaped structure with a hollow middle. The top 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 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 fixed to the top of the top crown conversion component 2 through the prestressed anchor cage 4.

[0023] Furthermore, the hollow portion of the main body foundation 1 is in a "Y" shape, and the angle between the hollow inner wall and the upper surface of the main body foundation is not less than 105°, thereby reducing stress concentration between the top crown conversion component and the main body 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 inner wall diameter of the foundation of the lower chamber 6 is larger than the arrangement diameter of the prestressed anchor cable 3 .

[0027] Furthermore, a steel casing 32 penetrating from top to bottom is arranged on the main foundation 1 and the top crown conversion component 2, 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 is a detailed description:

[0031] The top crown type wind turbine foundation structure with replaceable anchor bolts of the present invention comprises 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, thereby further enhancing the integrity of the foundation.

[0033] In this embodiment, the main loads borne by the wind turbine foundation are vertical force and bending moment, so stress concentration will occur between the top crown conversion component 2 and the main foundation 1. In order to minimize the stress concentration on the contact surface, a chamfered R angle can be set to make the shape change of the contact surface smooth and reduce the stress concentration. Therefore, the hollow part of the main foundation is "Y" shaped, that is, the angle between the hollow inner wall and the upper surface of the main foundation is not less than 105°; according to the characteristics of the anchor cage and the prestressed anchor cable transmitting force along the upper and lower tightening surfaces, the thickness of the top crown conversion component 2 inserted into the main foundation 1 is greater than the height of the inclined platform of the main foundation 1, so that the force is better transmitted to the lower base plate; under the action of the wind turbine load, the stress on the tensile side is mainly borne by the prestressed anchor cable 3, and the stress on the compressive side is mainly transmitted to the foundation by the overall foundation.

[0034] In this embodiment, the main foundation 1 and the top crown conversion component 2 are provided with a steel casing 32 in the height direction through which 16 to 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 an anti-corrosion sleeve 35 and a concrete protective sleeve 36 are added at the anchor to prevent corrosion or damage to the prestressed anchor cable.

[0035] In this embodiment, a 1m high manhole chamber 6 is arranged below the main foundation 1. The inner wall diameter of the foundation of the manhole chamber 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 cage 4; the bottom plate and the manhole chamber 6 can be cast separately, and a water-stop steel plate 7 needs to be arranged 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 cables.

[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 the anchor bolts during the capacity expansion and reconstruction of the fan is as follows:

[0039] (1) The original prestressed anchor cage 4 and prestressed anchor cable 3 are removed and recovered in sequence. An electric drill or electric hammer is used to drill holes at the contact surface between the main foundation 1 and the top crown conversion component 2 to increase the foundation detachment surface without damaging the main foundation 1. The top crown conversion component 2 is then lifted by a crane and removed by auxiliary cleaning.

[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 foundation open space, and a steel casing 32 is embedded in the foundation.

[0041] (3) The surface of the main foundation 1 is cleaned and leveled, and the local damaged areas are repaired with C40 grouting 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 only used to illustrate the technical ideas and features of the present invention, but is not limited to the current hollow angle, material grade, prestressed anchor cable, prefabricated components, construction tools, etc. Its purpose is to enable those skilled in the art to understand the content of the present invention and implement it accordingly. The patent scope of the present invention cannot be limited only by this embodiment, that is, any equivalent changes or modifications made to the spirit disclosed by the present invention still fall within the patent 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 body foundation (1) and a top crown conversion component (2). The main body 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 body foundation (1). The top crown conversion component (2) and the main body 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 top crown conversion component (2) by a prestressed anchor cage (4).

2. The crown-type wind turbine foundation structure with replaceable anchor bolts according to claim 1 is characterized in that: The hollow part of the main body foundation (1) is in a "Y" shape, and the angle between the hollow inner wall and the upper surface of the main body foundation is not less than 105°, thereby reducing the stress concentration between the top crown conversion component and the main body foundation during the force transmission process.

3. The crown-type wind turbine foundation structure with replaceable anchor bolts according to claim 1 is characterized in that: 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.

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

5. The crown-type wind turbine foundation structure with replaceable anchor bolts according to claim 4 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).

6. The crown-type wind turbine foundation structure with replaceable anchor bolts according to claim 1 is characterized in that: The main body foundation (1) and the top crown conversion component (2) are provided with a steel casing (32) that passes through the steel casing (32) and is then fixed.

7. The crown-type wind turbine foundation structure with replaceable anchor bolts according to claim 2 is characterized in that: 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).

8. The crown-type wind turbine foundation structure with replaceable anchor bolts according to claim 1 is characterized in that: 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).

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