Tough composite deep sea pumped storage structure

Abstract

The invention discloses a tough composite deep sea pumped storage structure, and belongs to the technical field of structural engineering. The whole tough composite deep sea pumped storage structure is in a spherical shell shape, and a spherical shell sequentially comprises a lining steel shell, a cast-in-place concrete middle layer and a concrete permanent formwork shell from inside to outside. The lining steel shell is formed by welding a plurality of spherical units, and a shearing force connecting piece is welded on the outer surface of the lining steel shell; the concrete permanent formwork shell is formed by splicing a plurality of curved-surface rectangular units prefabricated in a factory. The curved-surface rectangular units are poured by adopting ultrahigh-toughness concrete; a reinforcing mesh is arranged in the concrete permanent formwork shell, and connecting ribs are fixed to the reinforcing mesh and connected with the reinforcing mesh located in the cast-in-place concrete middle layer. According to the tough composite deep sea pumped storage structure provided by the invention, the excellent tensile property of the ultrahigh-toughness concrete can be fully utilized; the structure is excellent in bearing performance, high in assembly degree, high in durability and corrosion resistance and convenient to construct and transport.

Description

Technical Field

[0001] The invention relates to a tough composite deep-sea pumped storage structure, belonging to the technical field of structural engineering. Background Art

[0002] With the transformation of the global energy structure, the development of clean energy has become the core of the energy strategy of various countries. Seeking development, space and resources from the ocean has become an important trend and direction of global energy development. Marine renewable energy, such as offshore wind energy, tidal energy and wave energy, is gradually becoming a key source of energy in the future. my country has a vast marine territory and rich marine resources in various forms including wind energy, solar energy, wave energy, tidal energy and ocean current energy. In recent years, offshore wind power has become an important part of my country's renewable energy, and the development of marine energy in the future will play a vital role in my country's energy transformation.

[0003] Since offshore wind power and solar energy are intermittent and unstable, how to efficiently store these energies has become a difficult problem that needs to be solved in the process of offshore energy development and utilization. Pumped storage, as a mature energy storage technology, has been widely used in traditional hydropower stations. Applying pumped storage technology to offshore energy storage and developing pumped storage systems suitable for deep-sea environments are effective ways to achieve efficient utilization of offshore energy.

[0004] However, the particularity of the deep-sea environment makes the design of seawater pumped storage systems face huge challenges. The deep sea area has great water depth, high water pressure, strong corrosiveness of seawater, and complex and changeable marine climate, which makes the structure vulnerable to corrosion, fatigue damage and structural destruction, thus affecting the long-term stability and safety of the system. Extreme weather conditions such as waves and storm surges place higher demands on the impact resistance and toughness of the structure. Existing technologies have not yet completely solved the multiple challenges of high water pressure, corrosion, impact, etc. in the deep-sea environment, and cannot fully meet the special needs of deep-sea pumped storage systems.

[0005] In view of the above problems, it is necessary to design a tough composite deep-sea pumped storage structure that can effectively cope with the complex and harsh environment of high water pressure, strong corrosion and changeable climate in the deep sea area, ensure that the structure has good bearing capacity and toughness, so as to improve the long-term stability and durability of the seawater pumped storage system. Summary of the invention

[0006] In order to effectively cope with complex and harsh environments such as high water pressure and strong corrosion in deep sea areas, the present invention proposes a tough composite deep sea pumped storage structure suitable for pumped storage systems in deep sea environments.

[0007] The described resilient composite deep - sea pumped - storage structure is in the shape of a spherical shell as a whole. An opening is provided at the top of the spherical shell as the sea - water inlet and outlet. A base is provided at the bottom of the spherical shell for installing a mooring device to connect the structure to the seabed.

[0008] The spherical shell sequentially includes an inner lining steel shell, a cast - in - place concrete intermediate layer, and a concrete permanent formwork outer shell from the inside to the outside. The cast - in - place concrete intermediate layer is poured between the inner lining steel shell and the concrete permanent formwork outer shell.

[0009] Shear connectors are welded on the outer surface of the inner lining steel shell.

[0010] A second steel mesh is built into the concrete permanent formwork outer shell. Connecting bars are fixed to the second steel mesh. The connecting bars pass out of the concrete permanent formwork outer shell and are connected to the first steel mesh.

[0011] The first steel mesh is located within the cast - in - place concrete intermediate layer.

[0012] Furthermore, the inner lining steel plate is composed of multiple sequentially connected spherical surface units. The spherical surface units are formed into a spherical surface through cold - bending processing and are connected by welding when interconnected. The spherical surface units have different sizes according to the different latitudes of the spherical shell where they are located.

[0013] Furthermore, the shear connectors are stud bolts.

[0014] Furthermore, the concrete permanent formwork outer shell is pre - fabricated in a factory and is composed of multiple sequentially connected curved - surface rectangular units. The curved - surface rectangular units have a first boundary, a second boundary, a third boundary, and a fourth boundary in a clockwise order. Grooves are provided on the first boundary and the second boundary, and plugs are provided on the third boundary and the fourth boundary. The plugs of the curved - surface rectangular units are inserted into the grooves of the adjacent units to be interconnected. The curved - surface rectangular units have different sizes according to the different latitudes of the spherical shell where they are located.

[0015] Furthermore, the curved - surface rectangular units are cast with ultra - high - toughness concrete. The ultra - high - toughness concrete adopted in the present invention includes cement, active mineral admixtures, aggregates, reinforcing fibers, and water. Among them, the cement and active mineral admixtures adopt raw materials with the following weight percentages:

[0016]

[0017] The resilient composite deep - sea pumped - storage structure proposed by the present invention adopts a composite shell structure of "inner lining steel shell - cast - in - place concrete - ultra - high - toughness concrete permanent formwork" and has the following advantages:

[0018] (1) The overall structure adopts a composite spherical shell structure. The spherical shell structure can effectively disperse the huge water pressure from the deep sea, thereby improving the compressive capacity of the structure and avoiding local stress concentration.

[0019] (2) The inner steel shell is connected by welding, providing good watertight performance. At the same time, the permanent concrete formwork shell is cast with ultra-high toughness concrete. Ultra-high toughness concrete has the characteristics of strain hardening and multi-crack cracking, can resist the erosion of seawater in the deep-sea environment for a long time, effectively improve the corrosion resistance of the structure, significantly enhance the durability of the structure, enable the structure to operate stably in the deep-sea environment for a long time, and reduce the frequency of maintenance and replacement.

[0020] (3) Using ultra-high toughness concrete to cover the outer layer of the structure makes the structure have excellent impact resistance and fatigue performance, can effectively resist accidental loads such as the impact of marine organisms and fatigue loads such as ocean currents in the marine environment, prevent crack propagation and even structural damage caused by dynamic pressure changes in the deep-sea environment, and improve the fatigue performance of the structure.

[0021] (4) The inner steel shell and the permanent concrete formwork shell can be used as the inner and outer formworks respectively during the casting of the cast-in-place concrete intermediate layer. Moreover, the steel mesh has been arranged in advance during the prefabrication process of the permanent concrete formwork factory, avoiding the on-site arrangement of the steel mesh and concrete formwork, and greatly improving the construction efficiency. In addition, the number and size of the spherical units of the inner steel shell and the curved rectangular units of the permanent concrete formwork shell can be flexibly adjusted according to the actual transportation and installation conditions, without being restricted by the overall size of the structure. Description of the Drawings

[0022] Figure 1 Schematic diagram of the tough composite deep-sea pumped storage energy structure provided by the embodiment of the present invention.

[0023] Figure 2 is Figure 1 sectional view of.

[0024] Figure 3 Schematic diagram of the composition of the spherical shell of the tough composite deep-sea pumped storage energy structure in the embodiment of the present invention.

[0025] Figure 4 Partial schematic diagram of the inner steel shell.

[0026] Figure 5 Partial schematic diagram of the permanent concrete formwork shell.

[0027] Figure 6 Top view of the curved rectangular unit of the permanent concrete formwork shell.

[0028] Figure 7 is Figure 6 front view of.

[0029] Figure 8 is Figure 6 the left view of Specific Embodiments

[0030] The following will describe in detail the embodiments of the present invention with reference to the accompanying drawings.

[0031] Accompanying Figures 1 to 8 The reference numerals in the

[0032] drawings are as follows:

[0033] As Figure 1 and Figure 2 shown, a ductile composite deep - sea pumped - storage energy structure has an overall spherical - shell shape. There is an opening 1 at the top of the spherical shell 3, which serves as the seawater inlet and outlet. There is a base 2 at the bottom of the spherical shell 3 for installing a mooring device to connect the structure to the seabed.

[0034] As Figure 3 shown, the spherical shell 3 sequentially includes an inner lining steel shell 4, a cast - in - place concrete intermediate layer 5, and a concrete permanent formwork outer shell 6 from the inside to the outside. The cast - in - place concrete intermediate layer 5 is poured between the inner lining steel shell 4 and the concrete permanent formwork outer shell 6. Shear connectors 7 are welded to the outer surface of the inner lining steel shell 4. A second steel mesh 9 is arranged inside the concrete permanent formwork outer shell 6. Connecting bars 10 are fixed to the second steel mesh 9 and penetrate out of the concrete permanent formwork outer shell 6 to be connected to the first steel mesh 8. The first steel mesh 8 is located inside the cast - in - place concrete intermediate layer 5. Welding shear connectors on the surface of the inner lining steel shell can enhance the interfacial performance between the steel plate and the concrete. By designing to achieve full shear connection at the interface, it can ensure that the steel plate and the concrete jointly bear the load under the action of the load, and the interface does not fail prior to the concrete.

[0035] As Figure 4 shown, the inner lining steel shell 4 is composed of a plurality of sequentially connected spherical units 11. The spherical units 11 are formed into a spherical surface through cold bending. When the spherical units 11 are connected to each other, welding connection 12 is adopted. The advantage of using welding connection is that welding makes the inner lining steel shell form an integral body, effectively improving the watertightness of the structure. According to the different positions of the spherical units 11 at the latitude of the spherical shell, the spherical units 11 have different sizes.

[0036] AsFigure 5 As shown, the permanent concrete formwork shell 6 is prefabricated in a factory and is composed of a plurality of sequentially connected curved rectangular units 13 connected to each other by snap connections 14. As Figures 6 - 8 shown, the curved rectangular unit 13 sequentially has a first boundary 15, a second boundary 16, a third boundary 17, and a fourth boundary 18 in the clockwise direction; the first boundary 15 and the second boundary 16 have grooves, and the third boundary 17 and the fourth boundary 18 have inserts; the inserts of the curved rectangular unit 13 are inserted into the grooves of adjacent units, thereby connecting to each other to form the permanent concrete formwork shell 6; the curved rectangular unit 13 has different sizes according to the different latitudes of the spherical shell where it is located. The prefabrication method in the factory improves the control of the quality of the permanent concrete formwork shell. At the same time, by prefabricating the first steel mesh and the permanent concrete formwork shell at the same time, on-site steel bar binding is avoided. In addition, the cast-in-place concrete intermediate layer is cast-in-place. When casting-in-place, the inner lining steel shell and the permanent concrete formwork shell are the formwork for the cast-in-place concrete intermediate layer, avoiding on-site formwork erection and improving the construction efficiency.

[0037] The curved rectangular unit is cast with ultra-high toughness concrete 19. The composition of the ultra-high toughness concrete includes cement, active mineral admixtures, aggregates, fibers, and water. The active mineral admixtures include fly ash, silica fume, granulated blast furnace slag, and metakaolin. The maximum particle size of the aggregates does not exceed 0.5 mm. The fibers are one or more combinations of polyvinyl alcohol fibers, polyethylene fibers, and aromatic polyamide fibers. The fiber length is 5 mm to 25 mm, the diameter is 0.015 mm to 0.055 mm, the elastic modulus is 30 GPa to 150 GPa, the tensile strength is 1000 MPa to 3500 MPa, and the ultimate elongation is 2% to 15%. The weight ratio of each component of cement and active mineral admixtures is:

[0038]

[0039] Among them, a common weight ratio of each component of cement and active mineral admixtures is: cement: 30%; fly ash: 50%; silica fume: 7%; granulated blast furnace slag: 5%; metakaolin: 8%. The performance test of the ultra-high toughness concrete obtained under this mix ratio shows that its ultimate tensile strain can reach 3.2% (about 320 times that of concrete), the crack width corresponding to the ultimate tensile strain is 0.049 mm; the flexural strength is 12.8 MPa (about 2 times that of concrete), the uniaxial compressive strength is 48 MPa, and the compressive strain corresponding to the peak load is 0.55% (about 2 times that of concrete).

[0040] Taking the flexible composite deep-sea pumped storage energy structure with an inner diameter of 25 m as an example, the spherical shell is composed in the following way:

[0041] 1) The thickness of the inner steel shell is 12 mm, and the steel grade is Q355B;

[0042] 2) The thickness of the cast-in-place concrete intermediate layer is 588 mm, and the strength grade is C50;

[0043] 3) The thickness of the concrete permanent formwork outer shell is 50 mm, which is cast with ultra-high toughness concrete, and the ultra-high toughness concrete is prepared according to the above mix ratio.

[0044] Research shows that the tough composite deep-sea pumped storage energy structure obtained by the above composition can fully withstand the seawater pressure at a depth of 400 m; combined with a water turbine and a water pump with a rated power of 0.9 MW, the total energy storage capacity can reach 6000 kWh, and the charge and discharge time is 6.6 h. Compared with a concrete spherical shell of the same size, the tough composite deep-sea pumped storage energy structure proposed in the present invention can effectively reduce the maximum stress ratio by about 11%. In addition, the tough composite deep-sea pumped storage energy structure proposed in the present invention adopts a spherical shell structure, which avoids stress concentration in the structure and can better adapt to the high water pressure in the deep sea. The inner steel shell and the concrete permanent formwork outer shell adopted in the present invention can be used as formwork during the casting of the cast-in-place concrete intermediate layer, avoiding construction processes such as on-site formwork support for traditional concrete spherical shells, simplifying the construction process and shortening the construction period. The concrete permanent formwork outer shell in the present invention adopts ultra-high toughness concrete; the ultra-high toughness concrete can ensure that the structure does not produce or only produces microcracks less than 100 microns under tensile, compressive, bending and other various loads, playing the functions of crack resistance, anti-seepage and corrosion resistance, significantly improving the toughness and durability of the structure, and effectively reducing the maintenance cost during the service stage of the structure. Therefore, the tough composite deep-sea pumped storage energy structure proposed in the present invention has good bearing capacity and toughness, can effectively cope with complex and harsh environments such as high water pressure, strong corrosion and variable climate in the deep-sea area, and has the potential to be popularized and applied in deep-sea energy storage structures.

Claims

1. A ductile composite deep - sea pumped - storage structure, characterized in that, Comprising: Base; A spherical shell arranged on the base, with an opening provided at the top of the spherical shell as the seawater inlet and outlet; The spherical shell sequentially includes an inner lining steel shell, a cast-in-place concrete intermediate layer, and a concrete permanent formwork outer shell from inside to outside. The cast-in-place concrete intermediate layer is poured between the inner lining steel shell and the concrete permanent formwork outer shell; Shear connectors are welded on the outer surface of the inner lining steel shell; A second steel mesh is arranged inside the concrete permanent formwork outer shell. Connecting bars are fixed to the second steel mesh, and the connecting bars penetrate out of the concrete permanent formwork outer shell and are connected to the first steel mesh; The first steel mesh is located inside the cast-in-place concrete intermediate layer.

2. The resilient composite deep - sea pumped - storage structure according to claim 1, characterized in that, The inner lining steel shell is composed of a plurality of sequentially connected spherical surface units; when the spherical surface units are connected to each other, welding connection is adopted.

3. The resilient composite deep - sea pumped - storage structure according to claim 2, characterized in that, The spherical surface unit forms a spherical surface through cold bending processing.

4. The resilient composite deep - sea pumped - storage structure according to claim 1, wherein, The shear connector is a stud.

5. The resilient composite deep - sea pumped - storage structure according to claim 4, characterized in that, The concrete permanent formwork outer shell is composed of a plurality of sequentially connected curved surface rectangular units; The curved surface rectangular unit sequentially has a first boundary, a second boundary, a third boundary, and a fourth boundary in the clockwise direction. The first boundary and the second boundary have grooves, and the third boundary and the fourth boundary have inserts; The inserts of the curved surface rectangular unit are inserted into the grooves of the adjacent unit, and thus they are connected to each other.

6. The resilient composite deep - sea pumped - storage structure according to claim 1, characterized in that, The curved surface rectangular unit is poured with ultra-high toughness concrete, and the ultra-high toughness concrete adopts raw materials with the following weight percentages: Cement: 12% - 55%; Fly ash: 45% - 85%; Silica fume: 0 - 15%; Granulated blast furnace slag: 0 - 10%; Metakaolin: 0 - 20%.

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