A wind turbine foundation structure suitable for expanding existing old wind farms
By using components such as enlarged anchor plates and prestressed anchor bolts in old wind farms, the foundation connection problem in the expansion of old wind farms has been solved, achieving efficient and economical foundation renovation and improving the power generation capacity and safety of wind farms.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- 四川电力设计咨询有限责任公司
- Filing Date
- 2025-07-17
- Publication Date
- 2026-06-02
AI Technical Summary
In the expansion and renovation of old wind farms, the original foundation rings cannot meet the connection requirements of new towers, which leads to the need to demolish the existing foundations and rebuild new foundations, resulting in high costs, long construction periods and difficulties in replacing prestressed anchor bolt components.
The new wind power foundation is formed by using components such as enlarged anchor plates, lower anchor plates, upper anchor plates, and tower bottom flanges, which are connected to the original foundation ring through prestressed anchor bolts. The connection strength is enhanced by combining I-beams and welded steel bars, and the original foundation structure is modified.
This approach allows for direct expansion of the existing capacity, reducing construction costs and time, improving construction efficiency, enhancing the connection strength between new and old concrete, and ensuring safety and economic benefits.
Smart Images
Figure CN224314256U_ABST
Abstract
Description
Technical Field
[0001] This utility model belongs to the technical field of wind energy engineering and onshore wind power foundation structure, and relates to a wind turbine foundation structure suitable for the expansion of existing old wind farms. Background Technology
[0002] With the rapid development of my country's wind power industry, the cumulative number of grid-connected wind turbines has exceeded 140,000. Early grid-connected wind turbines have been in service for nearly or over 20 years, with relatively small individual capacities, and are mostly located in areas with abundant wind resources. As their operating time increases, the power generation capacity of these turbines declines, failure rates increase, safety hazards multiply, and operating and maintenance costs rise significantly. Simultaneously, with the wind power market entering the era of grid parity, the single-unit capacity of wind turbines in my country has entered the era of large megawatts. Small-capacity turbines not only have limited economic benefits but also waste land resources. Therefore, replacing old wind farms with larger-capacity turbines has become an inevitable trend in the industry. However, given the large number of old wind farms in my country and the scarcity of land resources, renovation work should be completed as much as possible at the existing turbine locations and on existing foundations, minimizing new land acquisition and demolition work.
[0003] Early wind turbine towers were typically made of steel, and the connection to the foundation usually involved foundation rings. When replacing with larger capacity turbines, the diameter of the tower base needs to be increased, and the original foundation rings cannot meet the connection requirements. Currently, expansion and renovation usually require demolishing the existing foundation and rebuilding a new one, which involves high costs, long construction periods, extensive excavation, and difficulties in replacing prestressed anchor bolt components. Therefore, there is an urgent need to develop a technology that allows for direct technical upgrades to existing wind turbine foundations, achieving a reliable connection between the large-capacity turbine tower and the foundation. This would fully utilize the foundation structure before it reaches its design service life, avoiding the numerous problems associated with redesigning and rebuilding the foundation, thereby promoting the efficient and economical renovation of older wind farms. Utility Model Content
[0004] In view of this, in order to solve the problems that exist in the technical transformation of the above-mentioned old wind farms, such as the original foundation ring being unable to meet the tower connection requirements after expansion, and the need to rebuild new foundations, which involves high cost, long construction period, large excavation and difficulty in replacing prestressed anchor bolt components, this utility model provides a wind turbine foundation structure suitable for the expansion of existing old wind farms.
[0005] To achieve the above objectives, this utility model provides the following technical solution:
[0006] A wind turbine foundation structure suitable for expanding existing old wind farms includes an enlarged anchor plate fitted around the original foundation column and adapted to the outer diameter of the original column, a lower anchor plate surrounding the enlarged anchor plate, an upper anchor plate corresponding to the lower anchor plate, and a tower bottom flange surrounding the upper anchor plate for connecting the new tower. The enlarged anchor plate is used for fixed connection with the original foundation truncated cone. Anchor bolt holes corresponding to the two rows of anchor bolt holes in the middle of the enlarged anchor plate are evenly opened on the lower anchor plate, the upper anchor plate, the lower anchor plate, and the tower bottom flange. Prestressed anchor bolts are inserted into the anchor bolt holes corresponding to the tower bottom flange, the upper anchor plate, the lower anchor plate, and the enlarged anchor plate to achieve a fixed connection between the tower bottom flange, the upper anchor plate, the lower anchor plate, and the enlarged anchor plate.
[0007] Furthermore, the outer diameter of the enlarged anchor plate is larger than that of the lower anchor plate. Five rows of anchor bolt holes are evenly opened on the enlarged anchor plate, and three rows of anchor bolt holes are evenly opened on the lower anchor plate. The outermost and innermost anchor bolt holes are fitted with enlarged bottom anchor bolts to facilitate the fixed connection between the enlarged anchor plate and the original foundation truncated cone. Fixed anchor bolts for fixing and leveling the lower anchor plate and the enlarged anchor plate are inserted into the anchor bolt holes in the middle layer between the enlarged anchor plate and the lower anchor plate. The fixed anchor bolts are pre-driven into the original foundation truncated cone, and the enlarged anchor plate and the lower anchor plate are placed on the fixed anchor bolts and leveled.
[0008] Furthermore, the free ends of both the expanded-base anchor bolts and the prestressed anchor bolts are fastened and fixed with steel nuts.
[0009] Furthermore, the tower bottom flange, upper anchor plate, lower anchor plate, and enlarged anchor plate form a prestressed anchor bolt assembly. I-beams are evenly arranged between the original foundation ring and the prestressed anchor bolt assembly in the original column. One end of the I-beam is welded to the original foundation ring to enhance the connection strength between the original foundation ring and the prestressed anchor bolt assembly.
[0010] Furthermore, several layers of pile holes are evenly opened at the outer diameter of the original foundation truncated cone. Steel pipes with several welded reinforcing bars evenly arranged on the periphery are evenly inserted into the pile holes. The welded reinforcing bars on the periphery of the steel pipes are evenly distributed and their ends are bent outwards, which increases the connection strength of the interface between the old and new truncated cones.
[0011] Furthermore, several rows of new and old interface reinforcement bars are evenly installed radially on the original foundation truncated cone. New tied reinforcement bars are installed in the area outside the prestressed anchor bolt assembly and the area outside the original foundation truncated cone. Concrete is poured in the area of the new tied reinforcement bars to form a new wind power foundation with the new foundation truncated cone and new columns integrally formed.
[0012] Furthermore, high-strength concrete is poured in the area between the upper surface of the new column and the upper anchor plate to form a grouting pad, and the cross-sectional shape of the grouting pad is annular.
[0013] The beneficial effects of this utility model are as follows:
[0014] 1. The wind turbine foundation structure disclosed in this utility model is applicable to the expansion of existing old wind farms. It has strong applicability, and conventional wind turbine foundation types in old wind farms can all be technically upgraded using this method. The upgraded wind turbine foundation is suitable for both concrete towers and steel towers. Furthermore, it can make full use of the existing foundation structure, eliminating the need to demolish the original foundation, avoiding the selection of new turbine sites and the acquisition of new land, thus saving land resources.
[0015] 2. The wind turbine foundation structure disclosed in this utility model, applicable to the expansion of existing old wind farms, has a simple construction process. All procedures can be implemented using conventional construction methods, which effectively improves the construction efficiency of wind turbine foundation technical transformation, accelerates the construction progress, and shortens the construction period. It avoids the need to re-pour the foundation, reduces the overall cost of technical transformation of old wind farms, and the replacement of large-capacity wind turbine units after technical transformation increases the power generation of wind farms, significantly improving the economic benefits of wind farms.
[0016] 3. The wind turbine foundation structure disclosed in this utility model, applicable to the expansion of existing old wind farms, has a steel pipe with welded reinforcing bars pre-installed in the pile hole at the outer diameter of the original foundation truncated cone. The welded reinforcing bars are evenly distributed around the steel pipe and the ends are bent outwards, which is beneficial to the connection strength of the interface between the original foundation truncated cone and the new foundation truncated cone, realizes the tight bonding between the old and new concrete, ensures the coordinated work of the old and new concrete, and has high safety.
[0017] Other advantages, objectives, and features of this invention will be set forth in part in the description which follows, and in part will be apparent to those skilled in the art from the following examination and study, or may be learned from practice of this invention. The objectives and other advantages of this invention can be realized and obtained through the following description. Attached Figure Description
[0018] To make the objectives, technical solutions, and advantages of this utility model clearer, the preferred embodiments of this utility model will be described in detail below with reference to the accompanying drawings, wherein:
[0019] Figure 1 This is a schematic diagram and a partial enlarged view of the wind turbine foundation structure of this utility model;
[0020] Figure 2 This utility model Figure 1 A structural diagram of the foundation structure of a medium-sized wind turbine;
[0021] Figure 3 This utility model Figure 1 Elevation view of the foundation structure of a medium-sized wind turbine;
[0022] Figure 4 This utility model Figure 1 Schematic diagram of the prestressed anchor bolt assembly;
[0023] Figure 5 This utility model Figure 1 Cross-sectional view and enlarged partial view of the foundation structure of the medium-sized wind turbine;
[0024] Figure 6 This is a construction flowchart of the wind turbine foundation structure of this utility model.
[0025] Attached reference numerals: 1. Original column; 2. Original foundation truncated cone; 3. Original foundation ring; 4. New column; 5. New foundation truncated cone; 6. I-beam; 7. Enlarged anchor plate; 8. Lower anchor plate; 9. Grouting material pad; 10. Upper anchor plate; 11. Tower bottom flange; 12. Enlarged bottom anchor bolt; 13. Prestressed anchor bolt; 14. Pile hole; 15. Steel pipe; 16. Welded reinforcing bar; 17. Newly tied reinforcing bar; 18. Rebar installation at the interface between old and new; 19. Prestressed anchor bolt assembly; 20. Fixed anchor bolt. Detailed Implementation
[0026] The following specific examples illustrate the implementation of this utility model. Those skilled in the art can easily understand other advantages and effects of this utility model from the content disclosed in this specification. This utility model can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this utility model.
[0027] The foundation ring is a key transition component between the wind turbine and the concrete foundation. It is usually a thick-walled steel cylinder, with its upper part connected to the tower via a flange and its lower part connected to the concrete foundation via a bottom flange.
[0028] like Figures 1-5 The wind turbine foundation structure shown is suitable for the expansion of existing old wind farms. It includes an enlarged anchor plate 7 fitted outside the original column 1 and adapted to the outer diameter of the original column 1, a lower anchor plate 8 surrounding the enlarged anchor plate 7, an upper anchor plate 10 corresponding to the lower anchor plate 8, and a tower bottom flange 11 surrounding the upper anchor plate 10 for connecting the new tower. The outer diameter of the enlarged anchor plate 7 is larger than the outer diameter of the lower anchor plate 8. Five rows of anchor bolt holes are evenly opened on the enlarged anchor plate 7. The outermost and innermost anchor bolt holes are fitted with enlarged bottom anchor bolts 12 to facilitate the fixed connection between the enlarged anchor plate 7 and the original foundation truncated cone 2. The lower anchor plate 8 is set on the enlarged bottom anchor bolts 12 and has three rows of anchor bolt holes. Fixed anchor bolts 20 pre-driven into the original foundation truncated cone 2 are inserted into the anchor bolt holes between the lower anchor plate 8 and the enlarged anchor plate 7, and the ends are tightened by steel nuts.
[0029] Two rows of anchor holes, corresponding to the inner and outer rows of anchor holes on the lower anchor plate 8, are evenly provided on the upper anchor plate 10 and the tower bottom flange 11. Suitable prestressed anchor bolts 13 are inserted into the corresponding anchor holes of the tower bottom flange 11, upper anchor plate 10, lower anchor plate 8, and enlarged anchor plate 7 to achieve a fixed connection between the tower bottom flange 11, upper anchor plate 10, lower anchor plate 8, and enlarged anchor plate 7. The free ends of the enlarged anchor bolts 12 and prestressed anchor bolts 13 are all tightened with steel nuts. The upper part of the tower bottom flange 11 is connected to the newly built, expanded tower via a new foundation ring and an expanded-diameter new flange.
[0030] The tower bottom flange 11, upper anchor plate 10, lower anchor plate 8, and enlarged anchor plate 7 form a structure as follows: Figure 4 The prestressed anchor bolt assembly 19 shown has I-beams 6 evenly arranged between the original foundation ring 3 in the original column 1 and the prestressed anchor bolt assembly 19. One end of the I-beam 6 is welded to the original foundation ring 3 to enhance the connection strength between the original foundation ring 3 and the prestressed anchor bolt assembly 19.
[0031] Two layers of pile holes 14 are evenly opened at the outer diameter of the original foundation truncated cone 2. Steel pipes 15 with several welded steel bars 16 evenly arranged on the periphery are evenly inserted in the pile holes 14. The welded steel bars 16 on the periphery of the steel pipes 15 are evenly distributed and the ends are bent outward, which is beneficial to the connection strength of the interface between the original foundation truncated cone 2 and the new foundation truncated cone 5.
[0032] Several rows of new and old interface reinforcement bars 18 are installed radially and evenly on the original foundation truncated cone 2. New tied reinforcement bars 17 are installed in the area outside the prestressed anchor bolt assembly 19 and the area outside the original foundation truncated cone 2. Concrete is poured in the area of the new tied reinforcement bars 17 to form a new wind power foundation with the new foundation truncated cone 5 and the new column 4 integrally formed.
[0033] High-strength concrete is poured in the area between the upper surface of the new column 4 and the upper anchor plate 10 to form a grouting pad 9, and the cross-sectional shape of the grouting pad 9 is annular.
[0034] like Figure 6 The construction method for wind turbine foundation structures applicable to the expansion of existing old wind farms, as shown, includes the following steps:
[0035] S1. Weld I-beams 6 evenly around the original foundation ring 3 in the original column 1. Insert fixed anchor bolts 20 at intervals on the original foundation truncated cone 2 at the root of the original column 1. Place the enlarged anchor plate 7 and the lower anchor plate 8 on the fixed anchor bolts 20 and level them. Two layers of pile holes 14 are evenly opened at the outer diameter of the original foundation truncated cone 2.
[0036] S2. After assembling the prestressed anchor bolt assembly consisting of the tower bottom flange 11, upper anchor plate 10, lower anchor plate 8 and enlarged anchor plate 7, it is fitted onto the outside of the original column 1. The outermost and innermost anchor bolt holes of the enlarged anchor plate 7 are fitted with enlarged bottom anchor bolts 12 and secured with steel nuts. A steel pipe 15 with welded steel bars 16 bent outwards on the periphery and lapped on the newly tied steel bars 17 is placed in the pile hole 14.
[0037] S3. Pressure grouting is performed into the pile hole 14, and the new and old interface rebars 18 are uniformly implanted radially along the original foundation frustum 2.
[0038] S4. Install new tied steel bars 17 in the area outside the prestressed anchor bolt assembly and outside the original foundation truncated cone 2.
[0039] S5, the newly tied steel bars 17 area is poured with concrete and backfilled with soil to form a new foundation 5, the new foundation 4, the new wind power foundation is formed in one piece.
[0040] S6. The newly built tower is connected to the bottom flange 11 of the tower through a new foundation ring and a new flange with an expanded diameter.
[0041] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of this utility model and are not intended to limit it. Although this utility model has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solution of this utility model without departing from the spirit and scope of this technical solution, and all such modifications or substitutions should be covered within the scope of the claims of this utility model.
Claims
1. A wind turbine foundation structure suitable for the expansion of existing old wind farms, characterized in that, The structure includes an enlarged anchor plate (7) fitted outside the original column (1) and adapted to the outer diameter of the original column (1), a lower anchor plate (8) surrounding the enlarged anchor plate (7), an upper anchor plate (10) corresponding to the lower anchor plate (8), and a tower bottom flange (11) surrounding the upper anchor plate (10) for connecting the new tower. The enlarged anchor plate (7) is used to fix the connection with the original foundation truncated cone (2). Anchor bolt holes corresponding to the two rows of anchor bolt holes in the enlarged anchor plate (7) are evenly opened on the lower anchor plate (8), the upper anchor plate (10), and the tower bottom flange (11). Prestressed anchor bolts (13) are inserted into the anchor bolt holes corresponding to the tower bottom flange (11), the upper anchor plate (10), the lower anchor plate (8), and the enlarged anchor plate (7) to achieve a fixed connection between the tower bottom flange (11), the upper anchor plate (10), the lower anchor plate (8), and the enlarged anchor plate (7).
2. The wind turbine foundation structure as described in claim 1, characterized in that, The outer diameter of the enlarged anchor plate (7) is larger than that of the lower anchor plate (8). Five rows of anchor bolt holes are evenly opened on the enlarged anchor plate (7), and three rows of anchor bolt holes are evenly opened on the lower anchor plate (8). The outermost and innermost anchor bolt holes are fitted with enlarged bottom anchor bolts (12) to facilitate the fixed connection between the enlarged anchor plate (7) and the original foundation truncated cone (2). The anchor bolt holes in the middle layer between the enlarged anchor plate (7) and the lower anchor plate (8) are fitted with fixing anchor bolts (20) for fixing and leveling the lower anchor plate (8) and the enlarged anchor plate (7).
3. The wind turbine foundation structure as described in claim 2, characterized in that, The free ends of the fixed anchor bolt (20), the expanded bottom anchor bolt (12), and the prestressed anchor bolt (13) are all fastened and fixed with steel nuts.
4. The wind turbine foundation structure as described in claim 1, characterized in that, The tower bottom flange (11), upper anchor plate (10), lower anchor plate (8) and enlarged anchor plate (7) form a prestressed anchor bolt assembly. I-beams (6) are evenly arranged between the original foundation ring (3) and the prestressed anchor bolt assembly in the original column (1). One end of the I-beam (6) is welded to the original foundation ring (3).
5. The wind turbine foundation structure as described in claim 1, characterized in that, Several rows of new and old interface reinforcement bars (18) are installed radially and evenly on the original foundation truncated cone (2). New tied reinforcement bars (17) are installed in the area outside the prestressed anchor bolt assembly and the area outside the original foundation truncated cone (2). Concrete is poured in the area of the new tied reinforcement bars (17) to form a new wind power foundation with the new foundation truncated cone and new column as one piece.
6. The wind turbine foundation structure as described in claim 5, characterized in that, Several layers of pile holes (14) are evenly opened at the outer diameter of the original foundation truncated cone (2). A steel pipe (15) with several welded steel bars (16) evenly arranged on the periphery is evenly inserted in the pile hole (14). The steel pipe (15) extends beyond the height of the original foundation truncated cone (2) for anchoring. The welded steel bars (16) on the periphery are evenly distributed and the ends are bent outwards and overlapped on the newly tied steel bars (17).
7. The wind turbine foundation structure as described in claim 6, characterized in that, High-strength concrete is poured in the area between the upper surface of the new column (4) and the upper anchor plate (10) to form a grouting pad (9), and the cross-sectional shape of the grouting pad (9) is annular.