Gate shaft with seawater desalination water taking facility
By designing seawater desalination water intake facilities in the circulating cooling water gate storage tank of nuclear power plants, and using submersible axial flow pump or liquid long-axis pump for seawater desalination, the problems of insufficient freshwater supply and environmental pollution in nuclear power plants are solved, and the reliability of freshwater sources is improved and reduces heat emissions.
Patent Information
- Application Number
- CN202411501018.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-25
- Publication Date
- 2025-01-14
AI Technical Summary
The seawater desalination water intake facilities of nuclear power plants in coastal areas have not yet been implemented on a large scale. It is difficult for existing technology to effectively use seawater desalination technology to provide sufficient fresh water. The high flow rate and high temperature drainage of the circulating cooling water of the nuclear power unit pose a threat to the environment.
Design a gate well for seawater desalination water intake facilities, including drain wells, cover plates, submersible axial flow pumps or liquid long shaft pumps, suction pools, communication holes and partition walls. By renovating the circulating cooling water gate storage tank of nuclear power plants, use Submersible axial flow pump or sub-liquid long-axis pump desalinates seawater and reduces heat emissions to the ocean.
It effectively reduces the circulating cooling water flow and flow rate of the nuclear power unit, improves the reliability of fresh water sources, and reduces heat emissions to the ocean through seawater desalination, protects the environment.
Smart Images
Figure CN119308270A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of nuclear energy comprehensive utilization technology, specifically relating to a gate well with seawater desalination water intake facilities. Background Technology
[0002] In recent years, with the widespread application of combined heat and power (CHP) technology in thermal power plants, nuclear power plants have also successively explored CHP projects. Freshwater supply is one of the most critical issues for CHP units. Currently, all approved nuclear power plants in my country are located in coastal areas, and reverse osmosis seawater desalination has become the trend for most coastal nuclear power plants. Seawater desalination technology is already maturely applied in my country. Some nuclear power units have also built small-scale seawater desalination facilities, but there are currently no large-scale nuclear power bases with seawater desalination facilities.
[0003] The nuclear power plant's freshwater usage was clearly defined during the initial design phase, and the flow rate of its water supply pipelines was determined during equipment manufacturing and installation. The externally supplied freshwater is sufficient to meet the unit's power generation needs. To enhance unit capacity and further integrate production, the nuclear power units will undergo further combined heat and power (CHP) retrofitting, requiring a significantly larger volume of freshwater. Since the original design of the nuclear power units did not provide sufficient freshwater, it is necessary to obtain freshwater through seawater desalination, while simultaneously determining the specific method of seawater intake.
[0004] Nuclear power plants use seawater as a coolant, which enters the unit to complete heat exchange and is then discharged into the sea through a circulating cooling water drainage system. Therefore, drawing water from the storage tank at the gate of the drainage tunnel is suitable. However, due to the large flow rate and velocity of the fluid within the drainage tunnel, water intake is not convenient. Therefore, there is an urgent need to propose a gate well with seawater desalination facilities to facilitate water intake. Summary of the Invention
[0005] The purpose of this invention is to provide a gate well with a seawater desalination water intake facility, which enables nuclear power units to produce fresh water through seawater desalination technology while ensuring nuclear safety, thereby effectively improving the reliability of the power plant's fresh water source.
[0006] Technical solution to achieve the purpose of this invention:
[0007] A gate well with a seawater desalination water intake facility includes: a drainage well, a cover plate, a submersible axial flow pump, a submersible long-shaft pump, a suction pool, a connecting hole, and a partition wall; a suction pool is provided on one side of the drainage well, and a partition wall is provided between the drainage well and the suction pool, with a connecting hole in the partition wall; a cover plate is provided on the top of the drainage well and the suction pool, and a submersible axial flow pump or a submersible long-shaft pump is provided on the cover plate on the top of the suction pool, with the water intake of the submersible axial flow pump or the submersible long-shaft pump located inside the suction pool and the water outlet located outside the suction pool.
[0008] The partition wall is a concrete partition wall.
[0009] The partition wall has two or more connecting holes.
[0010] The dimensions of the connecting hole are 2000mm × 1500mm.
[0011] The bottom elevation of the connecting hole is -6.5m.
[0012] The top cover of the water intake pool is equipped with three submersible axial flow pumps or submersible long shaft pumps, two for use and one for standby.
[0013] The bottom elevation of the submersible axial flow pump or submersible long shaft pump is -4.500m.
[0014] A maintenance staircase is provided on the other side of the drainage well, and a maintenance manhole is provided below the maintenance staircase.
[0015] The maintenance staircase has a partition wall on the side away from the drainage well to isolate different drainage wells.
[0016] The beneficial technical effects of this invention are as follows:
[0017] 1. The present invention provides a gate well with a seawater desalination water intake facility, which can effectively reduce the flow rate and velocity of circulating cooling water in nuclear power units and facilitate water intake.
[0018] 2. The gate well with seawater desalination water intake facility provided by the present invention transforms the gate storage tank in the shield gate well of the nuclear power unit's circulating cooling water drainage into a seawater desalination water intake facility, which can effectively reduce the emission of heat into the ocean and generate environmental benefits to a certain extent. Attached Figure Description
[0019] Figure 1 This is a top view of the original nuclear power plant's circulating cooling water drain gate;
[0020] Figure 2 This is a longitudinal section view of the original nuclear power plant's circulating cooling water drainage gate;
[0021] Figure 3 A top view of a gate well with a seawater desalination water intake facility provided by the present invention;
[0022] Figure 4 This is a longitudinal sectional view of a gate well with a seawater desalination water intake facility provided by the present invention.
[0023] In the diagram: 1: Unit drainage shield, 2: Drainage well, 3: Drainage culvert opening, 4: Cover plate, 5: Open drainage channel, 6: Inspection gate, 7: Inspection staircase, 8: Gate well, 9: Sump, 10: Ladder, 11: Gate storage tank, 12: Backfill sand, 13: Submersible axial flow pump, 14: Submersible long shaft pump, 15: Inspection manhole, 16: Suction pool, 17: Connecting hole, 18: Central partition wall, 19: Inspection handrail, 20: Partition wall. Detailed Implementation
[0024] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments.
[0025] The original nuclear power plant's circulating cooling water drain gate, such as Figure 1-2 As shown.
[0026] The flow velocity in the nuclear power plant's circulating cooling water drainage tunnel is relatively high, approximately 2.3 m / s, and the temperature is around 35℃. The influence of tide levels makes retaining wall construction in the drainage tunnel during routine operations difficult and poses high safety risks. Therefore, it is necessary to modify the gate storage tank 11 and backfill sand 12 sections of the original nuclear power plant's circulating cooling water gate well. A cofferdam will be constructed on one side of the original drainage tunnel gate storage tank 8 to create a waterless working area, facilitating subsequent routine seawater desalination water intake and drainage operations.
[0027] After the renovation, the overall structure of the original circulating cooling water drainage well remains unchanged, that is, it discharges into the sea through drainage well 2, drainage culvert opening 3 and open drainage channel 5. The original gate storage tank 11 and the partition wall of the storage tank are removed, the original precast cover plate and its supporting beam are partially removed, and the equipment foundation of submersible axial flow pump 13 or submersible long shaft pump 14 is added. A concrete partition wall 20 is added from the middle to the upper slab, and all the backfill sand 12 under the bottom platform is removed. This area is changed into the pump suction pool 16, and a connecting hole 17 is opened on the partition wall 20 of the suction pool 16.
[0028] Specifically, such as Figure 3-4 As shown, the present invention provides a gate well with a seawater desalination water intake facility, comprising: a drainage well 2, a cover plate 4, a submersible axial flow pump 13, a submersible long shaft pump 14, a water intake pool 16, a connecting hole 17, and a partition wall 20.
[0029] A water intake pool 16 is provided on one side of the drainage well 2. A partition wall 20 is provided between the drainage well 2 and the water intake pool 16. A connecting hole 17 is provided on the partition wall 20. Circulating cooling water enters the water intake pool 16 from the drainage well through the connecting hole 17. After the water level in the water intake pool 16 is the same as the water level in the drainage well 2, the water level in the water intake pool 16 stabilizes, and a still water area is formed in the water intake pool 16.
[0030] The drainage well 2 and the top of the suction pool 16 are equipped with a cover plate 4. A submersible axial flow pump 13 or a submersible long-shaft pump 14 is installed on the cover plate 4 on the top of the suction pool 16. The water intake of the submersible axial flow pump 13 or the submersible long-shaft pump 14 is located inside the suction pool 16, and the discharge outlet is located outside the suction pool 16. The submersible axial flow pump 13 or the submersible long-shaft pump 14 draws water through the suction pool 16, while circulating cooling water continuously enters the suction pool 16 from the connecting hole 17. The submersible axial flow pump 13 or the submersible long-shaft pump 14 provides water for the seawater desalination process.
[0031] In one specific embodiment, the partition wall 20 is a concrete partition wall.
[0032] In another specific embodiment, the partition wall 20 has two or more connecting holes 17, the size of the connecting holes 17 is 2000mm×1500mm, and the bottom elevation of the connecting holes 17 is -6.5m.
[0033] In another specific embodiment, three submersible axial flow pumps 13 or submersible long-shaft pumps 14 are installed on the cover plate 4 at the top of the suction tank 16, with two in use and one as a backup. The bottom elevation of the submersible axial flow pump 13 or submersible long-shaft pump 14 is -4.500m.
[0034] In another specific embodiment, a maintenance staircase 7 is provided on the other side of the drainage well 2, and a maintenance manhole 15 is provided below the maintenance staircase 7.
[0035] In another specific embodiment, the maintenance staircase 7 is provided with a partition wall 18 on the side away from the drainage well 2 to isolate different drainage wells 2.
[0036] This invention provides a gate well with a seawater desalination water intake facility, capable of drawing circulating cooling water. Circulating cooling water from the nuclear power unit enters the drainage well 2 through an open drainage channel 5, with a flow velocity of approximately 2.3 m / s. A portion of this circulating cooling water enters the intake pool 16 through a connecting hole 17 between the drainage well 2 and the still water area. According to the principle of communicating vessels, when the water level in the intake pool 17 is equal to the water level in the drainage well 2, the water volume in the intake pool 17 remains constant, with the water level varying according to the tides, averaging -1.770 m. Simultaneously, a submersible axial flow pump 13 or a submersible long-shaft pump 14 draws water from the intake pool 16, with the bottom elevation of the submersible axial flow pump 13 or the submersible long-shaft pump 14 being -4.500 m.
[0037] The present invention provides a gate well with a seawater desalination water intake facility, which transforms the gate storage tank in the shield gate well of the nuclear power unit's circulating cooling water drainage into a seawater desalination water intake facility, thereby generating environmental benefits to a certain extent.
[0038] Currently, all operating and under-construction nuclear power plant sites in my country are located on the coast, employing a single-cycle cooling system with seawater as the final heat sink. In power plants using a direct-flow cooling system, seawater is discharged into the ocean after heat exchange in a condenser. Because the temperature of the discharged cooling water is higher than that of the surrounding water, it is also known as warm discharge.
[0039] For power plants using a direct-flow cooling system, the vast majority of the heat is injected into the coastal waters along with the circulating cooling water. Taking a 6×1000MW nuclear power plant as an example, with six units operating simultaneously at the same site, the flow rate will be approximately 3500 m³ / s. 3 Warm wastewater, with a temperature 8-10°C higher than the water body temperature, is discharged into the receiving water body (the ocean). If this warm wastewater is not properly treated, it will harm the surrounding water bodies and aquatic ecosystems. By modifying the gate storage tanks in the gate wells to install seawater desalination facilities, an average of 45MW of heat discharge into the ocean can be reduced annually (based on a seawater desalination capacity of 100,000 t / h).
[0040] The present invention provides a gate well with a seawater desalination water intake facility, and the specific construction method is as follows:
[0041] Step 1: Positioning and Laying Out
[0042] Setting out benchmarks: Based on the coordinate elevation control points, transfer the points to the embedded points within the construction site to form a positioning control network, which serves as the basis for construction surveying, re-surveying, and verification.
[0043] (1) Surveying method: First, calculate the coordinate data of each corner point, and then use an electronic total station to survey and verify the control points to be constructed based on the control points that have been moved to the site and re-measured.
[0044] (2) Use the control points to enter the slab surface and pop out the cross control lines. After verification, use a 50m ruler to measure the positioning points of each component. Mark the positioning points of the inner lining wall on the slab with red paint. After the measurement is completed, report to the supervisor for acceptance.
[0045] (3) Use elevation control points as benchmarks.
[0046] Step 2, Base Plate Construction
[0047] After the concrete slab at the bottom of the gate well was removed, the original backfill sand was cleaned up in two ways: first, a long-arm excavator was used to clean up the sand layer; for areas that the machinery could not reach, manual loading and crane lifting were used for cleaning, and a 200mm thick cushion layer was poured before the bottom slab was constructed, which is 800mm thick double-layer bidirectional HRB400020@200 epoxy resin steel reinforcement.
[0048] After the backfill material in the gate well is cleared to 500mm below the bottom slab, the rebar installation is carried out. The rebar depth is 400mm, and the extension length of the rebar needs to meet the 50% lap length requirement. After the rebar installation is completed, the bottom slab rebar is tied, and the inner lining wall foundation is anchored into the bottom slab. After the rebar tying is completed, an 800mm thick bottom slab is poured and the surface is smoothed.
[0049] Step 3: Construction of the inner lining wall
[0050] The inner lining of the gate well is from the bottom plate to the middle plate. The wall is connected to the inner lining wall using HRB400ф14@500*500 rebar. After the rebar is installed, the surface is roughened as required. Since the inner lining wall cannot be connected by bolts, it is reinforced by mutual support at both ends. In order to offset the mutual stress, the wall is slowly raised by pouring concrete from all four sides at the same time to achieve stress balance.
[0051] The partition walls and inner lining walls are constructed using 13mm thick plywood, 40*90mm timber, and 48*3.5mm galvanized steel pipes as the main keel, reinforced with ф14 bolts.
[0052] Step 4: Construction at the gate well center plate
[0053] The upper part of the inner wall of the gate well (i.e., the middle plate) is a 1500mm concrete slab, which is connected to the original wall using HRB400014@500*500 rebar; the scaffolding is erected with a longitudinal and transverse spacing of 500mm and a step distance of 1800mm, with zigzag scissor bracing around the perimeter; the scaffolding is poured in two stages, with the first pour being 500mm thick, and the remaining height being poured after the design strength is reached.
[0054] Step 5: Construction at the top slab of the gate well
[0055] The top slab of the gate well is 1700mm thick and cantilevered above the culvert 10 (construction without interrupting water supply). H-beams are used as the main keel and fixed to the outer wall and the newly built wall with steel anchor plates. After fixing, profiled steel sheets are laid on the top as the bottom formwork. The wall at the position of the H-beams is reinforced with wooden formwork. The concrete is poured in two stages. The first pour is 500mm thick. After the concrete reaches the design strength, the remaining height is poured.
[0056] The present invention has been described in detail above with reference to the accompanying drawings and embodiments. However, the present invention is not limited to the above embodiments, and various changes can be made within the scope of knowledge possessed by those skilled in the art without departing from the spirit of the present invention. All contents not described in detail in the present invention can be derived from existing technologies.
Claims
1. A gate well with seawater desalination water intake facilities, characterized in that: The gate well comprises: a drainage well (2), a cover plate (4), a submersible axial flow pump (13), a submersible long-axis pump (14), a water suction pool (16), a connecting hole (17), and a partition wall (20); a water suction pool (16) is provided on one side of the drainage well (2); a partition wall (20) is provided between the drainage well (2) and the water suction pool (16); a connecting hole (17) is provided on the partition wall (20); a cover plate (4) is provided on the top of the drainage well (2) and the water suction pool (16); a submersible axial flow pump (13) or a submersible long-axis pump (14) is provided on the cover plate (4) on the top of the water suction pool (16); a water intake of the submersible axial flow pump (13) or the submersible long-axis pump (14) is located in the water suction pool (16), and a drainage outlet is located outside the water suction pool (16).
2. A gate well with seawater desalination water intake facilities according to claim 1, characterized in that: The partition wall (20) is a concrete partition wall.
3. A gate well with seawater desalination water intake facilities according to claim 1, characterized in that: The partition wall (20) is provided with two or more communicating holes (17).
4. A gate well with seawater desalination water intake facilities according to claim 1, characterized in that: The size of the communicating hole (17) is 2000 mm×1500 mm.
5. A gate well with seawater desalination water intake facilities according to claim 1, characterized in that: The bottom elevation of the connecting hole (17) is -6.5m.
6. A gate well with seawater desalination water intake facilities according to claim 1, characterized in that: Three submersible axial flow pumps (13) or submersible long axis pumps (14) are arranged on the cover plate (4) at the top of the water absorption pool (16), two for use and one for backup.
7. A gate well with seawater desalination water intake facilities according to claim 1, characterized in that: The bottom elevation of the submersible axial flow pump (13) or the submersible long-axis pump (14) is -4.500 m.
8. A gate well with seawater desalination water intake facilities according to claim 1, characterized in that: A maintenance staircase (7) is provided on the other side of the drainage well (2), and a maintenance manhole (15) is provided below the maintenance staircase (7).
9. A gate well with seawater desalination water intake facilities according to claim 8, characterized in that: A middle partition wall (18) is provided on the side of the inspection staircase (7) away from the drainage well (2) for isolating different drainage wells (2).