Seawater cooling tower and system applied to large nuclear power plant

Abstract

The utility model belongs to the technical field of seawater cooling towers, and particularly relates to a seawater cooling tower and system applied to a large nuclear power plant. Comprising a tower body, a dehydrator, a high-position secondary beam, a low-position secondary beam, a water spraying filler, a water collecting inclined plate and a water collecting tank are sequentially arranged in the tower body from top to bottom, and an outer ring central vertical shaft and an inner ring central vertical shaft are arranged in the middle of the tower body. The seawater cooling tower has the beneficial effects that circulating water with low salt content is supplemented to enter the high-position water distribution pipe and the corresponding spray heads, salt mist drifting drops escaping from the outlet of the cooling tower can be reduced, meanwhile, the salt mist drifting drops with high concentration ratio can be diluted into drifting drops with low salt content, and the influence and damage of salt deposition on plants, equipment and environments are effectively reduced. The protruding buffering rubber balls and the buffering soft foundations on the water collecting inclined plates of the seawater cooling tower play a role in buffering when circulating water falls off, salt mist drifting escaping from an outlet of the cooling tower can be reduced, and noise of the outlet of the cooling tower can be further reduced through energy dissipation.

Description

Technical Field

[0001] The utility model belongs to the technical field of seawater cooling towers, and particularly relates to a seawater cooling tower and system applied to large nuclear power plants. Background Art

[0002] For nearshore nuclear power plant sites in China, the distance from the sea is generally far. Considering both safety and economy, once-through cooling is not the best choice for nearshore nuclear power plants. Therefore, large-scale seawater cooling towers are adopted for the secondary circulation cooling method to replace the once-through cooling method.

[0003] Since nuclear power plants use units with a capacity of more than one million kilowatts, in order to reduce the intake and discharge of seawater and lower energy consumption, natural draft seawater cooling towers with a high concentration ratio and high-level water collection are mostly used. However, natural draft seawater cooling towers with a high concentration ratio and high-level water collection have many environmental problems such as drift droplets, salt mist, salt deposition, and noise, as well as safety problems such as icing in winter (for northern sites), which seriously affect the construction, expansion, and even the application for new sites of nearshore nuclear power plants. Summary of the Utility Model

[0004] The purpose of the utility model is to provide a seawater cooling tower and system applied to large nuclear power plants, ensuring that while the natural draft seawater cooling tower with a high concentration ratio guarantees the operation efficiency, it can effectively solve the existing related problems such as drift droplets, salt deposition, icing, and high noise.

[0005] The technical solution of the utility model is as follows: A seawater cooling tower applied to a large nuclear power plant includes a tower body. Inside the tower body, a demister, a high-level secondary beam, a low-level secondary beam, a splash fill, a water collection inclined plate, and a water collection tank are sequentially arranged from top to bottom. An outer ring central shaft well and an inner ring central shaft well are arranged at the middle position of the tower body.

[0006] A high-level water distribution pipe and corresponding nozzles are arranged below the high-level secondary beam.

[0007] A low-level water distribution pipe and corresponding nozzles are arranged below the low-level secondary beam.

[0008] The water collection inclined plate uses a plastic substrate as a support, and a buffer soft base is adhered to the upper surface. Buffer rubber balls are arranged on the buffer soft base.

[0009] The buffer soft base and buffer rubber balls are made of soft materials.

[0010] A wind-breaking inclined plate is placed below the water collection inclined plate.

[0011] The outer ring central shaft well and the inner ring central shaft well are located at the exact middle position of the cooling tower tower body; the outer ring central shaft well is connected to the low-level water distribution pipe through a reinforced concrete water trough, and the inner ring central shaft well is connected to the high-level water distribution pipe through a reinforced concrete water trough.

[0012] A seawater cooling tower system applied to a large nuclear power plant, comprising a circulating water make-up system and a circulating water system, and the circulating water make-up system is connected to the circulating water system.

[0013] The circulating water make-up system described above includes a make-up water pump, and the make-up water pump is connected to the circulating water system through pipelines and valves.

[0014] The circulating water system includes a circulating water pump, a condenser, the seawater cooling tower as described above, a water collection channel. The circulating water pump is connected to the condenser through pipelines and valves, the condenser is connected to the seawater cooling tower through pipelines and valves, a water collection channel is arranged in the seawater cooling tower, and the water collection channel is connected to the circulating water pump through pipelines and valves.

[0015] The beneficial effects of the present utility model are as follows: The seawater cooling tower uses circulating water with low salt content for make-up to enter the high-level water distribution pipe and corresponding nozzles, which can reduce the salt mist droplets escaping from the outlet of the cooling tower. At the same time, the salt mist droplets with high concentration ratio can be diluted into droplets with low salt content, effectively reducing the impact and damage of salt deposition on the plant, equipment and environment. The buffer rubber balls and buffer soft bases protruding on the water collection inclined plate of the seawater cooling tower, on the one hand, play a buffering role when the circulating water drops, which can reduce the salt mist droplets escaping from the outlet of the cooling tower, and on the other hand, can further reduce the noise at the outlet of the cooling tower by energy dissipation. The wind-breaking inclined plate of the seawater cooling tower can reduce the air intake in the outer area in the wind-breaking mode, achieving an anti-freezing effect; in the normal mode, it is placed under the water collection inclined plate, reducing the floor area and the impact on the cooling efficiency. Compared with the current annular noise reduction device and wind-breaking device added at the air inlet of the cooling tower, the seawater cooling tower has less impact on the cooling efficiency of the cooling tower when achieving the same noise reduction and anti-freezing effects. The seawater cooling tower has a variety of high-efficiency and environmental protection characteristics, meeting the requirements of the country for the environmental impact of industrial factory areas, with a flexible and convenient operation mode, and can be widely applied to large offshore nuclear power plants with multiple natural draft cooling towers, etc. Description of the Drawings

[0016] Figure 1 Schematic diagram of a seawater cooling tower system applied to a large nuclear power plant provided by the present utility model;

[0017] Figure 2 Semi-side sectional view of a seawater cooling tower applied to a large nuclear power plant provided by the present utility model;

[0018] Figure 3 Partially enlarged semi-side sectional view of a seawater cooling tower applied to a large nuclear power plant provided by the present utility model;

[0019] Figure 4 Partially enlarged view of the water collection inclined plate of a seawater cooling tower applied to a large nuclear power plant provided by the present utility model;

[0020] Figure 5 Schematic diagram of the working of the wind baffle of a seawater cooling tower applied to a large nuclear power plant provided by the present utility model.

[0021] In the figure: 1 make-up water pump, 2 circulating water pump, 3 condenser, 4 seawater cooling tower, 5 water collection channel, 41 tower body, 42 water eliminator, 43 high-order beam, 44 low-order beam, 45 water spraying filler, 46 water collection inclined plate, 47 water collection tank, 48 outer ring central shaft well, 49 inner ring central shaft well, 410 wind baffle, 411 low-level water distribution pipe, 412 high-level water distribution pipe, 461 buffer rubber ball, 462 buffer soft foundation, 4101 wind baffle wind blocking mode. Specific embodiments

[0022] To further illustrate the content, features and functions of the present utility model, the following will be a detailed description in combination with the drawings in the specification and specific embodiments, but the present utility model is not limited to these embodiments.

[0023] As Figure 2 and Figure 3 shown, a seawater cooling tower applied to a large nuclear power plant includes a tower body 41, a water eliminator 42, a high-order beam 43, a low-order beam 44, a water spraying filler 45, a water collection inclined plate 46, a water collection tank 47, an outer ring central shaft well 48, an inner ring central shaft well 49, a wind baffle 410, a low-level water distribution pipe 411 and a high-level water distribution pipe 412. Inside the tower body 41, a water eliminator 42, a high-order beam 43, a low-order beam 44, a water spraying filler 45, a water collection inclined plate 46 and a water collection tank 47 are arranged in sequence from top to bottom.

[0024] The water eliminator 42 and the water spraying filler 45 adopt S-wave thin sheets. The water spraying filler 45 is laid flat on the water spraying filler support frame in a unit assembly form, and the water collection inclined plate 46 and the water collection tank 47 are installed on the structural beams inside the cooling tower in a hoisting manner. There is no connection relationship between the water spraying filler 45, the water collection inclined plate 46 and the water collection tank 47. The lower part of the water collection inclined plate 46 is connected to the water collection tank 47 to ensure that the circulating water after heat exchange from the water spraying filler 45 is collected by the large-area water collection inclined plate 46 and then converges into the water collection tank 47. The outer ring central shaft well 48 and the inner ring central shaft well 49 are located in the exact middle position of the cooling tower tower body 41. The outer ring central shaft well 48 is connected to the low-level water distribution pipe 411 through a reinforced concrete water tank to ensure that the circulating water enters the low-level water distribution pipe 411 through the outer ring central shaft well 48 and is then sprayed into the water spraying filler; the inner ring central shaft well 49 is connected to the high-level water distribution pipe 412 through a reinforced concrete water tank to ensure that the circulating water make-up enters the high-level water distribution pipe 412 through the inner ring central shaft well 49 and is then sprayed onto the low-level water distribution pipe 411, colliding, merging and diluting with the rising circulating water droplets.

[0025] Seawater makeup with low salt content enters the high-level water distribution pipe 412 under the high-level secondary beam 43 and the corresponding nozzles through the central vertical shaft 49 in the inner ring; seawater circulating water with high salt content and high concentration ratio enters the low-level water distribution pipe 411 under the low-level secondary beam 44 and the corresponding nozzles through the central vertical shaft 48 in the outer ring. The low-level water distribution pipe 411 and the corresponding nozzles are consistent with the traditional cooling tower design scheme. The high-level water distribution pipe 412 and the corresponding nozzles are designed according to the theory of droplet impact and fusion. The water spray pipe 412 is a sealed pipeline, and the circulating water makeup pressure inside is higher, enabling the nozzles to spray the circulating water makeup in the form of droplets, and the droplet size range is consistent with the droplet size range that the water eliminator 42 can capture. The nozzle hole injection angle of the nozzles is larger, making the seawater makeup range sprayed by a single nozzle wider.

[0026] After starting the makeup water pump 1 to convey the circulating water makeup with low salt content to the makeup water branch of the central vertical shaft 49 in the inner ring of the seawater cooling tower 4, during the cooling process of the high-concentration circulating water with high salt content sprayed from the low-level water distribution pipe 411 and the corresponding nozzles in the water filling packing, droplets of different sizes are formed and move upward with the air. The upward-moving droplets will collide and fuse with the micro-droplets of the circulating water makeup sprayed from the high-level water distribution pipe 412 and the corresponding nozzles, forming new droplets with lower salt content and larger mass. Due to the increase in mass, the new droplets are more likely to be captured and recycled in the water eliminator due to greater inertia and flow back to the lower water filling packing 45. Only the droplets with smaller mass and reduced salt content will escape from the cooling tower outlet with the air. These droplets have a longer floating time and a larger diffusion range and will not cause serious salt deposition in the lower part, which can alleviate the impact on the plant, equipment, and environment.

[0027] As Figure 4 shown, the water collection inclined plate 46 is supported by a plastic substrate, and at the same time, a layer of soft materials such as silica gel, the buffer rubber balls 461 and the buffer soft base 462, are adhered to the upper surface. The buffer soft base 462 is adhered to the water collection inclined plate 46, and the buffer rubber balls 461 are connected to the buffer soft base 462. When the circulating water cooled by the water filling packing 45 drops onto the water collection inclined plate 46, the buffer soft base 462 can bend downward naturally according to the gravity of the circulating water.

[0028] During the operation of the cooling tower, a part of the falling circulating water lands on the buffer rubber balls 461, causing the buffer soft base 462 to bend, dissipating the energy of the circulating water, resulting in fewer micro-droplets formed by the collision and fragmentation of this part of the circulating water with the buffer rubber balls 461. Then, it flows to the buffer soft base 462 of the next layer and flows along the buffer soft base 462 to the water collection inclined plate 46. The formed micro-droplets collide and merge with each other in the grooves between the buffer rubber balls 461 and the buffer soft base 462 for recovery. Another part of the falling circulating water directly lands on the buffer soft base 462, and after multiple fragmentations and energy dissipations, it flows along the buffer soft base 462 to the water collection inclined plate 46. This structure not only reduces the micro-droplets generated by the collision of the circulating water with the water collection inclined plate 46, alleviating the salt deposition caused by the formation of floating droplets after the micro-droplets escape, but also converts the rigid collision between the circulating water and the water collection inclined plate 46 into a flexible collision after energy dissipation, significantly reducing the main noise source of this part as the cooling tower.

[0029] As Figure 5 shown, the wind deflector 410 is mostly applied to large high-level water collection cooling towers in northern regions. The cooling towers in this region use an internal and external zoning water distribution method for antifreeze, and the wind deflector 410 is placed at the lower part of the water collection inclined plate 46 in the outer zone.

[0030] The wind deflector 410 is connected to the water collection inclined plate 46 at the upper end of the water collection inclined plate 46 by means of a hinge, so the wind deflector 410 can rotate with the upper end of the water collection inclined plate 46 as the axis.

[0031] In winter, it can rotate around the upper central axis and connect to the buffer bosses on both sides of the water collection inclined plate 46 of the next layer, forming a narrow gap with the water collection inclined plate 46 to avoid damaging the structural integrity of the water collection inclined plate 46. At the same time, when the wind deflector rotates to the wind deflector wind blocking mode 4101, the rotation mechanism is locked. The upward movement of the cold air below can cause an upward component force on the wind deflector wind blocking mode 4101, overcoming the gravity of the wind deflector 410 falling and fitting more closely with the water collection inclined plate 410.

[0032] In winter, cancel the water distribution in the outer zone of the cooling tower, and then start the wind deflector 410 to the wind blocking mode. The wind deflector wind blocking mode 4101 in the outer zone and the water collection inclined plate 46 form a relatively closed folding surface, only retaining the water distribution and air inlet channels in the inner zone, reducing the air intake of the cooling tower. On the one hand, it avoids the by-pass of the air inlet from the outer zone after the water distribution in the outer zone stops, reducing the heat exchange efficiency in the inner zone; on the other hand, reducing the air intake in the outer zone can prevent the condensation / icing of water vapor and micro-droplets on the water spraying packing 45 in the outer zone, causing damage to the water spraying packing 45 in the outer zone. All parts of this part are made of materials such as plastic / nylon / glass fiber reinforced plastic that are resistant to seawater corrosion, with low cost, light weight, convenient maintenance, and long service life.

[0033] As Figure 1 and Figure 3As shown in the figure, a seawater cooling tower structure and system applied to a large nuclear power plant. The system includes a circulating water make-up system and a circulating water system. The circulating water make-up system consists of a make-up water pump 1 and corresponding pipelines and valves. The circulating water system consists of a circulating water pump 2, a condenser 3, a seawater cooling tower 4, a water collection channel 5 and corresponding pipelines and valves.

[0034] Among them, the make-up water pump 1 is connected to the high-level water distribution pipe 412 and corresponding nozzles through pipelines and valves. The make-up water pump 1 is also connected to the circulating water pump 2 through pipelines and valves. The circulating water pump 2 is connected to the condenser 3 through pipelines and valves. The condenser 3 is connected to the low-level water distribution pipe 411 and corresponding nozzles of the seawater cooling tower 4 through pipelines and valves. The seawater cooling tower 4 is provided with a water collection channel 5 including the water collection channel 5. The water collection channel 5 is connected to the pipeline between the make-up water pump 1 and the circulating water pump 2 through pipelines and valves.

[0035] Technologically, the circulating water make-up system includes two branches in total. The seawater make-up water with low salt content is respectively transported to the inner ring central shaft 49 inside the circulating water pump 2 and the seawater cooling tower 4 through the make-up water pump 1. Both the circulating water and the circulating water make-up water enter the inside of the cooling tower through the central shaft.

[0036] During the operation of the seawater cooling tower in summer, the circulating water volume increases, resulting in a large amount of circulating water with high salt content and high concentration ratio in the form of droplets moving upward with the air. At this time, the make-up water pump 1 is started to transport the circulating water make-up water with low salt content to the inner ring central shaft 49 inside the seawater cooling tower 4. Or when the salt deposition is relatively serious around the cooling tower, the same make-up water branch is also started; in other seasons or when the salt deposition is relatively light around the cooling tower, the make-up water branch is closed and the circulating water make-up water in the branch is emptied. On the one hand, during the period when the salt deposition is relatively serious, starting this make-up water branch can effectively reduce the amount of salt mist droplets escaping from the cooling tower outlet. At the same time, the salt mist droplets with high concentration ratio can be diluted to reduce the salt content of the escaping salt mist droplets; on the other hand, for the high-level water collection tower in the seawater cooling tower, the head of the make-up water pump 1 itself has reached the upper liquid level of the water collection channel 5. At this time, only a small increase in head is required to reach the high-level water distribution pipe 412. Enabling this branch does not require additional water resources and a large amount of energy and electric energy consumption.

Claims

1. A seawater cooling tower applied to a large nuclear power plant, characterized in that: It includes a tower body, in which a water eliminator, a high-level secondary beam, a low-level secondary beam, a water spray packing, a water collection inclined plate and a water collection trough are sequentially arranged from top to bottom. An outer ring central shaft well and an inner ring central shaft well are arranged at the middle position of the tower body.

2. The seawater cooling tower applied to a large nuclear power plant as claimed in claim 1, wherein: A high-level water distribution pipe and corresponding nozzles are arranged below the high-level secondary beam.

3. The seawater cooling tower applied to a large nuclear power plant according to claim 1, wherein: A low-level water distribution pipe and corresponding nozzles are arranged below the low-level secondary beam.

4. The seawater cooling tower applied to a large nuclear power plant according to claim 1, wherein: The water collection inclined plate has a buffer soft base adhered to the upper surface with a plastic substrate as the support, and buffer rubber balls are arranged on the buffer soft base.

5. The seawater cooling tower applied to a large nuclear power plant according to claim 4, wherein: The buffer soft base and the buffer rubber balls are made of soft materials.

6. The seawater cooling tower applied to a large nuclear power plant according to claim 4, characterized in that: A wind blocking inclined plate is placed below the water collection inclined plate.

7. The seawater cooling tower applied to a large nuclear power plant according to claim 4, characterized in that: The outer ring central shaft well and the inner ring central shaft well are located at the exact middle position of the cooling tower body; the outer ring central shaft well is connected to the low-level water distribution pipe through a reinforced concrete water trough, and the inner ring central shaft well is connected to the high-level water distribution pipe through a reinforced concrete water trough.

8. A seawater cooling tower system applied to a large nuclear power plant, characterized in that: It includes a circulating water make-up system and a circulating water system, and the circulating water make-up system is connected to the circulating water system.

9. The seawater cooling tower system applied to a large nuclear power plant according to claim 8, wherein: The circulating water make-up system includes a make-up water pump, and the make-up water pump is connected to the circulating water system through pipelines and valves.

10. A seawater cooling tower system applied to a large nuclear power plant as claimed in claim 8, characterized in that: The circulating water system includes a circulating water pump, a condenser, the seawater cooling tower as claimed in claims 1-7, a water collection flow channel. The circulating water pump is connected to the condenser through pipelines and valves, the condenser is connected to the seawater cooling tower through pipelines and valves, a water collection flow channel is arranged in the seawater cooling tower, and the water collection flow channel is connected to the circulating water pump through pipelines and valves.

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