A marine intake structure for a seawater pumped storage power plant and a method of construction

Abstract

The application discloses a kind of ocean water inlet structure and construction method for seawater pumped storage power station, comprising: water intake head, set below seabed surface, for high-performance reinforced concrete structure, overall is the capsule-like closed shell with semicircular shape at both ends and rectangular shape in the middle;Multiple water inlet windows are provided on the side wall of the water intake head, which are connected inside and outside, the water inlet windows are at least provided as upper and lower layers along the height direction, and the upper and lower layers are staggered in horizontal projection;The shore sewage disposal well is arranged on the shore and adopts a semi-overhead reinforced concrete box structure;The water conduit connects the water intake head and the shore sewage disposal well, the sea area section adopts a prefabricated reinforced concrete structure, and the land section adopts a cast-in-place reinforced concrete structure;It can adapt to high tidal range, high sand content and strong biological attachment sea area environment, ensure smooth water intake, reduce sedimentation and biological attachment, stable structure and easy maintenance.

Description

Technical Field

[0001] This invention relates to the field of seawater pumped storage power station technology, specifically to a marine inlet structure and construction method for a seawater pumped storage power station. Background Technology

[0002] With the rapid development of renewable energy, seawater pumped storage power stations, as a highly efficient and environmentally friendly large-scale energy storage method, are receiving increasing attention. Conventional pumped storage power stations consist of upper and lower reservoirs. A common configuration uses the ocean as the lower reservoir and a reservoir built at a location with a suitable elevation difference as the upper reservoir, utilizing the water level difference between the two reservoirs to achieve energy storage and power generation. Meanwhile, with the deepening development and utilization of marine resources, a new configuration has emerged, using the ocean as the upper reservoir and utilizing abandoned underwater tunnels, artificially excavated caverns, or natural sea basins as the corresponding lower reservoir, also achieving energy storage and power generation through water level differences. The ocean inlet, as a key component of the seawater pumped storage system, directly affects the smoothness of water flow, equipment durability, and impact on the marine ecological environment.

[0003] However, in certain marine areas with high tide differences, high sediment content, and strong biofouling, existing technologies often employ funnel-shaped inlet structures, combined with single-layer inlet grilles and simple rock-filled foundations. While these structures can generally meet the requirements in conventional marine areas, they reveal numerous shortcomings when applied to special marine environments with high tide differences (maximum tidal range > 5m), high sediment content, and strong biofouling. First, single-layer intake windows are only suitable for fixed water levels. At low tide, the windows are exposed, making continuous water intake impossible and affecting the power station's peak-shaving capacity. Second, suspended sediment in high-sediment-content sea areas tends to deposit at the intake, and traditional dredging requires shutting down the unit, resulting in high operation and maintenance costs. Third, marine organisms such as shellfish and algae tend to adhere to the grid and flow surfaces. Existing periodic chemical dosing methods cannot match the real-time dynamics of biological growth, easily leading to chemical waste or antifouling failure. Fourth, traditional riprap foundations have weak erosion resistance, and under the long-term action of waves and ocean currents, problems such as foundation scouring, structural settlement, and overturning are likely to occur. Fifth, the construction of fully cast-in-place channels requires the construction of large-area underwater cofferdams, resulting in long construction periods, significant influence from sea conditions, and easy damage to the joint sealing structure, leading to a high risk of leakage later. Summary of the Invention

[0004] To address the problems existing in the prior art, this invention provides a marine inlet structure and construction method for a seawater pumped storage power station, which can adapt to marine environments with high tide differences, high sediment content, and strong biological attachment, ensuring smooth water intake, reducing siltation and biological attachment, structural stability, and ease of maintenance.

[0005] The technical solution of the present invention is as follows: In a first aspect of the invention, a marine inlet structure for a seawater pumped storage power station is provided, comprising: The water intake head is located below the seabed and is a high-performance reinforced concrete structure. It is a capsule-shaped closed shell with semi-circular ends and a rectangular middle. The side wall of the water intake head is provided with multiple water inlet windows that connect the inside and outside. The water inlet windows are set in at least two layers along the height direction, and the upper and lower layers of windows are staggered in the horizontal projection. The shore-side cleaning well is located on the shore and adopts a semi-above-ground reinforced concrete box structure. The water intake pipe connects the water intake head to the shore cleaning well. The marine section adopts a precast reinforced concrete structure, while the land section adopts a cast-in-place reinforced concrete structure. In some embodiments of the present invention, a bidirectional stainless steel grille is provided at the water inlet window, and the grille bars of the stainless steel grille have an airfoil-shaped cross-section.

[0006] In some embodiments of the present invention, the bottom of the water intake head is a sand collection trough, which is connected to a sand discharge pipe buried at the bottom of the water guide pipe. The outlet end of the sand discharge pipe is led to a cleaning well on the bank and is equipped with a control valve.

[0007] In some embodiments of the present invention, the bottom sill of the low-level water inlet window is provided with a downwardly sloping sand guide slope.

[0008] In some embodiments of the present invention, at least one chemical delivery pipe is pre-embedded in the top or side wall of the water guide pipe. The chemical delivery pipe is distributed along the semi-circular side wall of the water intake head. Multiple micro-holes are opened or nozzles are installed along the chemical delivery pipe. The beginning of the chemical delivery pipe is connected to an intelligent dosing device in the shore cleaning well.

[0009] In some embodiments of the present invention, at least one chemical delivery pipe is pre-embedded in the top or side wall of the water guide pipe. The chemical delivery pipe is distributed along the semi-circular side wall of the water intake head. Multiple micro-holes are opened or nozzles are installed along the chemical delivery pipe. The beginning of the chemical delivery pipe is connected to an intelligent dosing device in the shore cleaning well.

[0010] In some embodiments of the present invention, a compacted base bed is provided below the water intake head, the base bed thickness is 0.8m-1.2m, and it is compacted with 10-100kg stones; 10-100kg stones are thrown at the bottom sill of the water inlet to form a cone-shaped anti-erosion protection structure surrounding the bottom of the water intake head.

[0011] In some embodiments of the present invention, the water diversion pipe is a single-hole channel with a rectangular cross-section, a width of 1.8m to 2.2m, a height of 1.8m to 2.2m, and a length determined according to the distance between the water intake head and the bank.

[0012] In some embodiments of the present invention, a navigational warning device and a collision avoidance device are provided near the water intake head.

[0013] In a second aspect of the invention, a construction method for a marine inlet structure for a seawater pumped storage power station is provided, comprising the following steps: Step 1: Treat the seabed at the designed intake location and lay a compacted base bed; Step 2: Prefabricate and install the water intake head, and fill the bottom sill of the water inlet with boulders to form a truncated cone protective structure; Step 3: Construct cleaning wells on the shore; Step 4: The marine section of the water diversion pipeline is installed in sections using a prefabricated structure, with a rubble bed laid, connecting sections and waterproofing the joints. Step 5: Cast-in-place construction of the land section of the water diversion pipeline, connecting it with the sea section; Step 6: Apply an anti-corrosion coating to the inner wall of the water pipe; Step 7: Pre-bury the chemical delivery pipe and connect it to the chemical dosing device inside the cleaning well; Step 8: Install navigational warning devices and collision avoidance devices; Step 9: Run the system after debugging.

[0014] One or more technical solutions of the present invention have the following beneficial effects: 1. This invention effectively increases the water intake area and optimizes the water intake efficiency by setting a capsule-shaped water intake head with semicircles at both ends and a rectangle in the middle, combined with multiple water intake windows arranged vertically and vertically on the side walls and a bidirectional stainless steel grid. At the same time, the streamlined design of the arc-shaped side walls can effectively disperse and buffer the impact of waves, significantly reducing the direct impact of wave loads on the main structure, thereby improving the durability and operational reliability of the water intake head under harsh sea conditions.

[0015] 2. This invention utilizes a capsule-shaped water intake head in conjunction with a double-layered staggered water intake window. This design not only disperses wave impact through the arc-shaped contour but also adapts to high tide differences through the staggered arrangement of the high and low-level windows, ensuring stable water intake at all tide levels. Furthermore, a sand-guiding slope guides the high-sediment-laden water flow from the bottom layer into the bottom sand collection trough, which, in conjunction with the sand discharge pipe, enables regular active dredging, reducing sediment ingress at the source. Simultaneously, the wing-shaped bidirectional stainless steel bar reduces head loss during forward water intake and achieves self-cleaning through the jet effect during reverse drainage. This is further enhanced by real-time monitoring and feedback from the pre-buried chemical delivery pipe and the intelligent dosing device.

[0016] 3. By setting up a fully compacted rammed foundation and an outer frustum-shaped boulders protective structure, this invention forms a stable bottom support and protection system that can effectively resist the long-term scouring and erosion of waves and ocean currents, prevent soil loss below the water intake foundation, and fundamentally ensure the long-term structural stability and safety of the water intake in complex marine environments.

[0017] 4. The present invention has specially set up a dense rock foundation bed below the water diversion pipeline in the sea area. This structure provides a uniform and solid bearing foundation for the prefabricated reinforced concrete channel unit above, which can effectively distribute the load and prevent the channel structure from cracking, misalignment or leakage caused by uneven settlement of the foundation, thus ensuring the integrity and long-term service performance of the entire water conveyance system.

[0018] 5. This invention adopts a combined construction method of "prefabrication and installation in the sea area and on-site casting in the land area", which makes full use of the advantages of controllable quality and quick installation of prefabricated components. At the same time, it significantly reduces the high-difficulty and high-risk underwater operation links and time, significantly reduces the overall construction technical difficulty, safety risks and project cost, and improves the efficiency and controllability of project construction.

[0019] 6. By setting up conspicuous navigational warning devices and robust anti-collision devices in key waters around the water intake head, the present invention clearly marks the location and scope of underwater structures, which can effectively warn and guide passing ships and provide buffer protection in case of accidents, thereby maximizing the navigation safety of the waters above and near the water intake head and avoiding potential damage to the water intake facilities caused by ship collisions. Attached Figure Description

[0020] Figure 1 This is a top view of the inlet structure of the present invention; Figure 2 for Figure 1 Cross-sectional view at point 1-1.

[0021] In the diagram: 1. Anti-pollution and sand-blocking wall; 2. Water intake sidewall; 3. Reinforced concrete support column; 4. Chemical outlet orifice; 5. Chemical inlet pipe; 6. Two-way stainless steel grating; 7. Water guide pipe; 8. Sand guide slope; 9. Sand discharge pipe. Detailed Implementation

[0022] It should be noted that the following detailed description is illustrative and intended to provide further explanation of the invention. Unless otherwise specified, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0023] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of exemplary embodiments according to the invention. As used herein, unless otherwise expressly indicated by the invention, the singular form is intended to include the plural form as well. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0024] Example 1 In a typical embodiment of the present invention, a marine inlet structure for a seawater pumped storage power station is proposed, such as... Figure 1 and Figure 2 As shown, it includes: The water intake head, located below the sea surface, is a high-performance reinforced concrete structure. It is a capsule-shaped closed shell with semi-circular ends and a rectangular center. This unique structure combines excellent compressive and bending resistance with good hydrodynamic characteristics, effectively resisting seawater corrosion and wave impact. The sidewalls of the water intake head have multiple inlet windows connecting the inside and outside. These inlet windows are arranged in at least two layers along the height direction, with the upper and lower layers staggered in their horizontal projection. This staggered arrangement optimizes the water flow distribution, reduces local eddies, and prevents large floating objects from simultaneously blocking multiple windows, ensuring a stable water intake flow.

[0025] The shore-side cleaning well is located on the shore and adopts a semi-above-ground reinforced concrete box structure. Its above-ground portion facilitates equipment installation, maintenance, and personnel operation, while its underground portion smoothly connects to the water diversion pipeline. The well typically houses a trash rack, a cleaning machine, and necessary monitoring and control equipment. The shore-side cleaning well has a plan dimension of 18m×4m~20m×5m, a height of 12m~14m, a top elevation of 5.5m~6.5m, and a bottom elevation of -7.5m~-6.5m.

[0026] The water diversion pipeline 7 connects the water intake head to the shore cleaning well and is a key water conveyance channel for transporting seawater from the water intake point to the shore treatment facility. In the marine section, due to its location in the ocean environment, a precast reinforced concrete structure is used to reduce the difficulty of underwater operations, ensure structural quality, and accelerate the construction progress. In the land section, due to its relatively convenient construction conditions, a cast-in-place reinforced concrete structure is used to better adapt to terrain changes and to be closely connected with shore structures.

[0027] To ensure effective water intake, a bidirectional stainless steel grille 6 is installed at the water intake window. The grille 6 has an airfoil-shaped cross-section. This airfoil-shaped cross-section design minimizes resistance and reduces head loss when water flows in the forward direction. During reverse flushing, it generates a jet to wash the surface of the grille 6. Its special contour guides the water flow and provides a certain degree of self-cleaning ability, reducing the attachment of marine organisms and clogging by debris.

[0028] In this embodiment, the bottom of the water intake head is a sand collection trough, used to collect silt particles that enter and settle with seawater. The sand collection trough is connected to a sand discharge pipe 9 buried at the bottom of the water guide pipe 7. The outlet end of the sand discharge pipe 9 leads to a shore cleaning well and is equipped with a control valve. By periodically opening the valve, the silt is flushed out of the well using water pressure or by connecting a pumping system, thereby maintaining the unobstructed flow of the internal channels of the water intake head and preventing siltation from affecting the water intake efficiency.

[0029] In this embodiment, the bottom sill of the low-level water intake window is provided with a downwardly sloping sand guide slope 8. This sand guide slope 8 structure can guide the sediment carried by the bottom water flow with high sediment content near the bottom of the seabed to slide down the slope to the sand collection trough at the bottom of the water intake head under the action of gravity and water flow backflow, instead of entering the water intake window, thereby reducing sediment intake at the source and reducing the subsequent cleaning burden and channel wear.

[0030] In this embodiment, at least one drug inlet pipe 5 is pre-embedded in the top or side wall of the water guide pipe 7. The drug inlet pipe 5 is distributed along the semi-circular side wall of the water intake head to achieve uniform addition of the agent in the water intake window area. The drug inlet pipe 5 has multiple drug outlet holes 4 or is equipped with nozzles along its route to release the anti-marine organism attachment agent or water quality conditioning agent into the water in the form of atomization or fine stream. The beginning of the drug inlet pipe 5 is connected to the intelligent dosing device in the shore cleaning well to realize remote supply and dosage control of the agent.

[0031] Furthermore, the intelligent dosing device includes a chemical storage tank, a metering pump, and a biofouling monitoring module. The biofouling monitoring module is an electrochemical or ultrasonic sensor installed at the inlet window grille 6, used to monitor the biofilm thickness or scaling on the surface of grille 6 in real time or periodically, or linked with the differential water level gauges before and after grille 6. Monitoring data is fed back to the control system. When the monitored parameters exceed a set threshold, the metering pump automatically starts, releasing antifouling agents into the intake area and the inner wall of the channel, achieving precise, on-demand antifouling control. The antifouling agent is a sodium hypochlorite solution produced by seawater electrolysis or an environmentally friendly biodegrader.

[0032] In this embodiment, a compacted foundation bed is set below the water intake head to provide uniform and stable foundation support. The foundation bed is 0.8m-1.2m thick and is formed by compacting layers of 10-100kg boulders. At the bottom sill of the intake, 10-100kg boulders are thrown to form a truncated cone-shaped erosion protection structure surrounding the bottom of the water intake head. This truncated cone structure can effectively disperse and weaken the erosion force of the bottom water flow on the water intake head foundation and the surrounding seabed, preventing foundation erosion and ensuring the long-term stability of the water intake head structure.

[0033] In this embodiment, the water diversion pipe 7 is a single-hole channel with a rectangular cross-section, a width of 1.8m to 2.2m, and a height of 1.8m to 2.2m. This size range has been optimized through hydraulic calculations to meet the design flow requirements and structural strength while also considering construction convenience and economy. Its length is determined based on the actual distance between the water intake head and the shoreline cleaning well, taking into account factors such as topography, geology, water depth, and construction conditions. The joint length of the water diversion pipe 7 is 15m to 25m, and a circular rubber-plastic waterstop is installed at the joint. Geotextile is laid on both sides of the joint of the water diversion pipe 7 and within a width of 1.5m to 2.5m on the top plate, wrapped with U-shaped steel components, and bagged concrete is poured into the steel components for protection.

[0034] In this embodiment, a navigational warning device and a collision avoidance device are installed near the water intake head. The navigational warning device is used to clearly mark the location of the water intake head during the day and night, warning passing vessels to avoid it; the collision avoidance device is a buffer structure (such as rubber fenders, anti-collision piles, etc.) installed around the water intake head to absorb impact energy when a vessel accidentally approaches or collides with it, protecting the main structure of the water intake head from damage.

[0035] The working principle of this embodiment, where the water intake is used as the lower reservoir (the ocean as the lower reservoir and the high-level reservoir on the shore as the upper reservoir), is as follows: During the charging (pumping) phase, the unit operates as a water pump, consuming electricity. Seawater is drawn in through the double-layered staggered windows of the capsule-shaped water intake head, passes through the forward-flowing airfoil stainless steel grid, is pre-filtered by the anti-fouling and sand-blocking wall, and is then transported to the shore cleaning well via the water guide pipe. Finally, it is pressurized and lifted to the high-level reservoir to store potential energy. During the discharging (power generation) phase, the unit switches to a water turbine. Water in the high-level reservoir flows through the unit to generate electricity by gravity. The tailwater returns along the original path, flows into the water intake head through the water guide pipe, and is discharged back into the sea through the window. At this time, the reverse water flow automatically washes away the marine organisms attached to the surface using the jet effect of the airfoil grid, achieving self-cleaning.

[0036] The working principle of this embodiment, where the water intake is used as the upper reservoir (the ocean as the upper reservoir and the seabed cavern or basin as the lower reservoir), is as follows: During the charging (pumping) phase, the unit operates as a pump, consuming electricity to pump water from the subsea reservoir through a water diversion pipe to a capsule-shaped intake located on the seabed. Because the intake is enclosed and its top is below sea level, seawater is stored in a closed volume formed by the seabed, the intake shell, and a fouling barrier, creating high-pressure potential energy (pressure energy). During the discharging (power generation) phase, the unit switches to a turbine, and the high-pressure seawater stored in the intake, driven by pressure energy, flows back to the subsea reservoir through the water diversion pipe, impacting the downstream unit to generate electricity. Tailwater is discharged into the subsea reservoir. During this process, water flows forward through the main flow channel, and during downtime, the stored water in the channel can be used to backwash the grid to prevent blockage. This embodiment uses a seawater pumped storage power station in Jiaozhou Bay as an example to provide a marine intake structure.

[0037] (I) Project Overview The installed capacity of this project is 1350kW. The lower reservoir utilizes the existing seabed parallel guide tunnel (total capacity 56800m³). The water intake point is located on the west side of the plant area, about 980m from the shore, with a mud surface elevation of -4.1m.

[0038] (ii) Water intake head like Figure 1 , Figure 2 As shown, the intake head is located below the seabed surface, at a mud level of -4.1m. The intake head is a reinforced concrete structure, with semi-circular ends (4.9m radius) and a rectangular middle section (4.5m length), a height of 8.2m, and a wall thickness of 0.6m. A longitudinal anti-fouling and sand-blocking wall 1 is installed in the middle to prevent some bottom sand and floating debris from directly entering the water diversion pipe. The upper sill of the intake window is at an elevation of -2.50m, and the lower sill is at an elevation of -3.50m.

[0039] Eight windows are provided along the side wall, and the windows are separated by reinforced concrete columns 3, with a column cross-section of 0.5m × 0.5m. The windows are equipped with bidirectional stainless steel grilles 6, made of 316L stainless steel, with a grille spacing of 100mm, arranged in both directions.

[0040] A compacted foundation bed is constructed below the water intake head, with a thickness of 0.8m-1.2m. It is compacted in layers using 10-100kg stones, ensuring the surface flatness error does not exceed ±50mm. At the bottom sill of the water intake, 10-100kg stones are placed to form a truncated cone-shaped protective structure. The truncated cone has a base width of 3.0m, a top width of 1.5m, and a height of 1.0m, and is arranged around the bottom perimeter of the water intake head.

[0041] A navigational beacon warning device and a collision avoidance device are installed near the water intake. The navigational beacon warning device uses solar-powered navigation lights that automatically illuminate at night; the collision avoidance device consists of rubber fenders and is located at the four outer corners of the water intake.

[0042] (iii) Water diversion pipeline The water diversion pipeline, approximately 980m long, connects the water intake head to the shore-side cleaning well. It is a single-hole rectangular cross-section, 2.0m wide and 2.0m high. The marine section uses a precast reinforced concrete structure, with each section 20m long, 0.25m thick, and C40 concrete strength. A 1.0m thick rubble foundation is provided below. The sections use socket joints with rubber waterstops. The land section uses a cast-in-place reinforced concrete structure. The inner wall of the water diversion pipeline is coated with an epoxy coal tar anti-corrosion coating, 0.5mm thick. A chemical delivery pipe is pre-embedded at the top of the water diversion pipeline and connected to the chemical dosing device in the shore-side cleaning well.

[0043] (iv) Bankside cleaning wells The shore-side cleaning well was constructed using open-cut, cast-in-place construction. It measures 19.0m x 4.0m, with a top elevation of 6.0m and a bottom elevation of -7.0m. It employs a semi-above-ground reinforced concrete box-type structure. The well wall thickness is 0.5m, the bottom slab thickness is 0.8m, the concrete strength grade is C40, and the impermeability grade is P8.

[0044] The cleaning well is equipped with a cleaning grating and a maintenance platform. The cleaning grating has a 50mm spacing between the bars and is made of stainless steel. The maintenance platform is located in the middle of the cleaning well and is made of hot-dip galvanized steel grating with a load-bearing capacity of not less than 5kN / m². The top of the cleaning well is equipped with an openable sealed cover, on which is installed a maintenance manhole (0.8m in diameter) and a ventilation pipe (DN150).

[0045] (v) Construction methods The construction method in this embodiment includes the following steps: Step 1: At the designed intake location, the seabed is treated to remove floating mud and debris from the seabed, and a compacted base bed is laid. The base bed is compacted in layers using 10-100kg stones, with each layer being 0.3m-0.5m thick, and the base bed thickness is 1.0m. Step 2: Precast the reinforced concrete structure of the water intake head, and place it in place using the floating method. The water intake head sits on the compacted foundation bed, and 10-100kg stones are thrown at the bottom sill of the water inlet to form a truncated cone protective structure. Step 3: Construct a construction cofferdam on the bank to create a dry working environment, and construct the bank cleaning well by large-scale excavation and in-situ casting; Step 4: The sea section of the water diversion pipeline adopts a precast reinforced concrete structure. After prefabrication in sections (each section is 20m long), it is installed underwater by a crane vessel. First, the precast sections are placed on the rubble foundation bed. After adjusting the elevation and axis, the joints between the sections are connected and rubber waterstops are installed. Step 5: The land section of the water diversion pipeline adopts a cast-in-place reinforced concrete structure and connects with the sea section of the water diversion pipeline. An expansion joint with a width of 20mm is set at the connection point, which is filled with asphalt hemp fiber and wrapped with waterproof membrane. Step 6: Lay the chemical delivery pipe along the ditch on top of the installed water diversion pipe, and construct a concrete trench for protection. Cover the trench with boulders. Lead the beginning of the chemical delivery pipe into the cleaning well on the bank and connect it to the reserved interface of the chemical delivery facility. Step 7: Apply an anti-corrosion coating to the inner wall of the water pipe 7. The coating material is epoxy coal tar pitch, with a thickness of 0.5 mm, applied in two coats. Step 8: Install navigational warning devices and collision avoidance devices near the water intake; Step 9: After the system is debugged and put into operation, start the chlorine production facility, test the smoothness of the chemical delivery pipeline, test parameters such as water intake flow rate and water level difference before and after the screen, and put it into operation after acceptance.

[0046] Example 2 The difference between this embodiment and Embodiment 1 lies in the size of the water intake head and the number of water inlet windows.

[0047] Considering the larger tidal range in the sea area where this project is located (the maximum tidal range exceeds 5m), in order to ensure the stability of water intake at low tide, this embodiment increases the height of the water intake head to 9.5m, the upper sill elevation of the water intake window is -2.0m, the lower sill elevation is -4.5m, and the effective water intake height is increased to 2.5m; the number of water intake windows is increased to 10, while the window width remains unchanged.

[0048] The thickness of the compacted foundation bed below the water intake head was increased to 1.2m, and the bottom width of the truncated cone protective structure was increased to 3.5m and the height was increased to 1.2m to enhance its scour resistance.

[0049] The remaining structural parameters and construction methods are the same as in Example 1 (including the laying of the chemical delivery pipe at the top of the water diversion pipeline, protection of the concrete trench, and connection of the interface with the chlorine production facility in the cleaning well, etc.), and will not be repeated here.

[0050] Example 3 The difference between this embodiment and Embodiment 1 lies in the segmented prefabrication method of the water diversion pipe and the interface sealing method.

[0051] Considering the large waves in the sea area where this project is located, to enhance the reliability and sealing of the connection between the prefabricated sections of the water diversion pipeline, this embodiment features tenon and grommet joints at both ends of the prefabricated sections. The tenon is 150mm long, and the groove is 160mm deep. Double rubber waterstops are installed at the joints (one at the root of the tenon and one at the end). During installation, epoxy resin sealant is applied to the surface of the tenon, which is then inserted into the groove, and compacted by its own weight and the waves.

[0052] The remaining structural parameters and construction methods are the same as in Example 1 (including the laying of the chemical delivery pipe at the top of the water diversion pipeline, protection of the concrete trench, and connection of the interface with the chlorine production facility in the cleaning well, etc.), and will not be repeated here.

[0053] Example 4 In a typical embodiment of this invention, a construction method for a marine inlet structure of a seawater pumped storage power station is provided, comprising the following steps: Step 1: At the designed water intake location, the seabed is treated by removing the surface soft silt or uneven rock surface. Then, a base bed consisting of 10-100kg stones is laid and compacted, with each layer 0.3m-0.5m thick and the base bed thickness 0.8m-1.2m, forming a flat and solid foundation.

[0054] Step 2: Complete the overall or segmented prefabrication of the water intake head in the onshore prefabrication plant, and use the floating method or crane vessel to lift and position it. The water intake head sits on the compacted foundation bed. Subsequently, 10-100kg of boulders are dumped into the water area around the bottom sill of the water intake to form the truncated cone protective structure required by the design.

[0055] Step 3: Construct a construction cofferdam on the bank to create a dry working environment, and construct the bank cleaning well by large-scale excavation and in-situ casting.

[0056] Step 4: The sea section of the water diversion pipeline adopts a precast reinforced concrete structure. After prefabrication in sections (each section is 15m to 25m in length), it is installed underwater by a crane vessel. First, the precast sections are placed on the rubble foundation bed. After adjusting the elevation and axis, the joints between the sections are connected by spigot and socket joints. Circular rubber and plastic waterstops are installed at the joints. Geotextile is laid at the joints, U-shaped steel components are wrapped around them, and bagged concrete is used for protection.

[0057] Step 5: The land section of the water diversion pipeline adopts a cast-in-place reinforced concrete structure and connects with the sea section of the water diversion pipeline. An expansion joint with a width of 20mm is set at the connection point, which is filled with asphalt hemp fiber and wrapped with waterproof membrane.

[0058] Step 6: Apply an anti-corrosion coating to the inner wall of the water diversion pipe. The coating material is epoxy coal tar pitch, with a thickness of 0.5mm. Apply it in two coats to extend the service life of the channel and reduce maintenance requirements.

[0059] Step 7: Embed the chemical delivery pipe in the top or side wall of the water diversion pipeline and construct a concrete trench for protection. Cover the trench with boulders. Introduce the beginning of the chemical delivery pipe into the cleaning well on the bank and connect it to the reserved interface of the intelligent dosing device.

[0060] Step 8: Install navigation lights, buoys and other warning devices, as well as anti-collision devices such as bollards and fenders in and around the water intake to complete the installation of safety protection facilities.

[0061] Step 9: Conduct joint commissioning of the entire inlet system, including checking the connection and sealing of each structural component, testing the functional linkage and coordination of each subsystem such as water intake, cleaning, sand removal, and chemical dosing, to ensure that the entire structure can operate normally according to design requirements.

[0062] While the specific embodiments of the present invention have been described above in conjunction with the accompanying drawings, this is not intended to limit the scope of protection of the present invention. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art without creative effort based on the technical solutions of the present invention are still within the scope of protection of the present invention.

Claims

1. A marine inlet structure for a seawater pumped storage power station, characterized in that, include: The water intake head is located below the seabed and is a high-performance reinforced concrete structure. It is a capsule-shaped closed shell with semi-circular ends and a rectangular middle. The side wall of the water intake head is provided with multiple water inlet windows that connect the inside and outside. The water inlet windows are set in at least two layers along the height direction, and the upper and lower layers of windows are staggered in the horizontal projection. The shore-side cleaning well is located on the shore and adopts a semi-above-ground reinforced concrete box structure. The water intake pipe connects the water intake head to the shore cleaning well. The marine section adopts a precast reinforced concrete structure, while the land section adopts a cast-in-place reinforced concrete structure.

2. The marine inlet structure for a seawater pumped storage power station as described in claim 1, characterized in that, A bidirectional stainless steel grille is installed at the water inlet window, and the grille bars have an airfoil-shaped cross-section.

3. The marine inlet structure for a seawater pumped storage power station as described in claim 1, characterized in that, The bottom of the water intake head is a sand collection trough, which is connected to a sand discharge pipe buried at the bottom of the water diversion pipeline. The outlet end of the sand discharge pipe is led to the sewage cleaning well on the bank and is equipped with a control valve.

4. The marine inlet structure for a seawater pumped storage power station as described in claim 1, characterized in that, The bottom sill of the low-level water inlet window is equipped with a downward-sloping sand guide slope.

5. The marine inlet structure for a seawater pumped storage power station as described in claim 1, characterized in that, At least one chemical delivery pipe is pre-embedded in the top or side wall of the water guide pipe. The chemical delivery pipe is distributed along the semi-circular side wall of the water intake head. Multiple micro-holes are opened or nozzles are installed along the chemical delivery pipe. The beginning of the chemical delivery pipe is connected to the intelligent dosing device in the shore cleaning well.

6. The marine inlet structure for a seawater pumped storage power station as described in claim 5, characterized in that, The intelligent dosing device includes a chemical storage tank, a metering pump, and a biofilm monitoring module; the biofilm monitoring module is an electrochemical sensor or an ultrasonic sensor installed at the water inlet window, used to monitor the biofilm thickness or scaling on the surface of the grid.

7. The marine inlet structure for a seawater pumped storage power station as described in claim 1, characterized in that, A compacted foundation bed with a thickness of 0.8m-1.2m is set below the water intake head, and it is compacted with 10-100kg stones. 10-100kg stones are thrown at the bottom sill of the water inlet to form a cone-shaped anti-erosion protection structure around the bottom of the water intake head.

8. The marine inlet structure for a seawater pumped storage power station as described in claim 1, characterized in that, The water diversion pipe is a single-hole channel with a rectangular cross-section, a width of 1.8m to 2.2m, a height of 1.8m to 2.2m, and a length determined by the distance between the water intake head and the bank.

9. The marine inlet structure for a seawater pumped storage power station as described in claim 1, characterized in that, Navigational warning devices and collision avoidance devices are installed near the water intake.

10. A construction method for a marine inlet structure for a seawater pumped storage power station as described in any one of claims 1-9, characterized in that, Includes the following steps: Step 1: Treat the seabed at the designed intake location and lay a compacted base bed; Step 2: Prefabricate and install the water intake head, and fill the bottom sill of the water inlet with boulders to form a truncated cone protective structure; Step 3: Construct cleaning wells on the shore; Step 4: The marine section of the water diversion pipeline is installed in sections using a prefabricated structure, with a rubble bed laid, connecting sections and waterproofing the joints. Step 5: Cast-in-place construction of the land section of the water diversion pipeline, connecting it with the sea section; Step 6: Apply an anti-corrosion coating to the inner wall of the water pipe; Step 7: Pre-bury the chemical delivery pipe and connect it to the chemical dosing device inside the cleaning well; Step 8: Install navigational warning devices and collision avoidance devices; Step 9: Run the system after debugging.

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