A salt control and demisting natural draft cooling tower and its working method
By introducing an alternating combination of dry and wet cooling zones into the natural draft cooling tower, the problems of fog plume and salt deposition are solved, achieving efficient cooling and environmentally friendly emissions, and avoiding the hazards of fog plume and salt deposition.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- ANHUI UNIVERSITY OF TECHNOLOGY
- Filing Date
- 2026-03-30
- Publication Date
- 2026-05-29
AI Technical Summary
Natural draft wet cooling towers can create fog plumes when exhausting hot and humid air, which can affect visibility and corrode surrounding buildings. Salt spray emissions from the seawater circulating medium can lead to salt deposits that harm the ecosystem. In addition, natural draft dry cooling towers have low cooling efficiency.
A salt-controlled, demisting natural ventilation cooling tower is designed, which adopts an alternating combination structure of dry and wet cooling zones. By coordinating the dry and wet cooling zones, the dry cooling zone reduces the air temperature and humidity, suppresses the formation of mist plumes, promotes the evaporation of salt droplets, and avoids salt deposition.
It achieves the effects of suppressing fog plume formation, improving cooling efficiency, reducing salt deposition, saving water, and protecting the environment.
Smart Images
Figure CN122107811A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of cooling tower technology, specifically relating to a salt-controlled, demisting, natural ventilation cooling tower and its working method. Background Technology
[0002] As an important cold-end equipment, natural draft wet cooling towers are widely used in thermal power and nuclear power systems due to their advantages of large circulating water volume and high cooling efficiency. The function of a natural draft wet cooling tower is to exchange heat and mass with the air inside the tower, so that the waste heat is transferred to the air and dissipated into the atmosphere. The air-water heat exchange mode in a natural draft wet cooling tower includes evaporative heat transfer and convective heat transfer. This causes some circulating water to evaporate, and the resulting hot and humid air is difficult to recover and eventually dissipates into the ambient atmosphere. At the same time, the discharged hot and humid air will carry liquid circulating water droplets (drips) and dissipate into the ambient atmosphere. When the hot and humid air discharged from the tower encounters the dry and cold ambient air, it will condense and produce small water droplets, forming visible mist. The mist will reduce the visibility of the surrounding area, create a shading effect, corrode buildings around the cooling tower, and harm the human respiratory system. If the cooling tower uses seawater as the circulating working fluid, the emitted salt mist is prone to causing salt deposition, which will harm the ecosystem around the cooling tower.
[0003] Natural draft dry cooling towers cool circulating water by arranging heat exchangers. The indirect heat exchange method used isolates the circulating water from the air. Therefore, the air temperature only increases when passing through the heat exchanger, while its moisture content remains unchanged. At the same time, the hot air discharged from the natural draft dry cooling tower does not carry droplets, and it does not generate mist when discharged into the ambient atmosphere. However, the cooling efficiency of natural draft dry cooling towers for circulating water is lower than that of natural draft wet cooling towers. Therefore, a salt-controlled and demisting natural draft cooling tower is proposed. Summary of the Invention
[0004] In order to solve the technical problems existing in the prior art, the present invention provides a salt-controlled demisting natural ventilation cooling tower and its working method.
[0005] To solve the above-mentioned technical problems, the present invention provides the following technical solution: a salt-controlled demisting natural ventilation cooling tower, comprising a tower body, a water separator, and a water collection tank. The water separator is disposed inside the upper part of the tower body, and the water collection tank is disposed at the bottom of the tower body. A total cooling zone is disposed inside the lower part of the tower body. The total cooling zone is composed of alternating wet cooling zones and dry cooling zones. The wet cooling zones and dry cooling zones are used to change the temperature and humidity of the air flowing through them.
[0006] Preferably, the wet and cold zone includes a wet and cold zone water distribution pipeline, water spray nozzles, and filler. The wet and cold zone water distribution pipeline is installed below the water separator via a bracket. Several sets of water spray nozzles are distributed at the bottom of the wet and cold zone water distribution pipeline. The water spray nozzles are used to spray the circulating water in the wet and cold zone water distribution pipeline to form a spray area. The filler is installed above the water collection tank via a bracket, and the filler is matched with the spray area.
[0007] Preferably, the dry cooling zone includes a dry cooling zone water distribution pipeline and a heat exchanger. The dry cooling zone water distribution pipeline is installed below the water separator via a bracket. Several groups of heat exchangers are alternately arranged between the packing material. Each group of heat exchangers is connected to the dry cooling zone water distribution pipeline via a pipe and valve assembly.
[0008] Preferably, the area of the dry cooling zone accounts for 10% to 50% of the total cooling zone area, and the area of the wet cooling zone accounts for 50% to 90% of the total cooling zone area.
[0009] Preferably, the drain outlet of the heat exchanger is connected to the water collection tank and the water distribution pipeline of the wet and cold zone respectively through a three-way valve, and the circulating water enters the water collection tank or the water distribution pipeline of the wet and cold zone through the three-way valve.
[0010] Preferably, the arrangement shape of the dry cooling zone includes, but is not limited to, concentric rings, rectangles, triangles, and combinations of concentric rings, rectangles, and triangles.
[0011] Preferably, the dry-cooling zone is a concentric ring, with the height of several dry-cooling zones arranged from the inside out increasing progressively.
[0012] Preferably, the dry-cooling zone has a mixed rectangular and triangular configuration, with the rectangular dry-cooling zone facing the windward side and the triangular dry-cooling zone facing the leeward side.
[0013] A method for operating a salt-controlled, demisting, natural ventilation cooling tower includes the following steps:
[0014] Step S1, salt control and demisting: When the ambient temperature is below 10℃, 50% to 80% of the circulating water is sent into the heat exchanger through the dry cooling zone water distribution pipeline and valve assembly, and 20% to 50% of the circulating water is sent into the wet cooling zone water distribution pipeline. The wet cooling zone water distribution pipeline sprays the circulating water onto the packing surface through water spray nozzles.
[0015] In step S2, ambient air enters both the humid and dry cooling zones simultaneously from outside the tower. The air rises through the packing material. The air entering the humid cooling zone exchanges heat and mass with the packing material. When the air leaves the humid cooling zone, both its temperature and moisture content increase, and it forms droplets.
[0016] In step S3, the air entering the dry and cold zone rises through the heat exchanger, where it exchanges heat with the heat exchanger. When the air leaves the dry and cold zone, its moisture content remains unchanged, but its temperature rises.
[0017] The air leaving the dry and cold zone and the humid and cold zone mix with each other. The temperature and humidity of the mixed air are lower than those of the air leaving the humid and cold zone, thus completely removing the fog.
[0018] Step S4: When the ambient temperature is 10℃~30℃, 30%~50% of the circulating water is sent into the heat exchanger through the dry cooling zone water distribution pipeline and valve assembly. After heat exchange in the heat exchanger, 0~100% of the circulating water is sent into the wet cooling zone water distribution pipeline for secondary cooling in the wet cooling zone.
[0019] Step S5: When the ambient temperature is higher than 30℃, 10% to 30% of the circulating water is sent into the heat exchanger through the dry cooling zone water distribution pipeline and valve assembly. All (100%) of the circulating water after heat exchange in the heat exchanger is sent into the wet cooling zone water distribution pipeline for secondary cooling in the wet cooling zone.
[0020] Preferably, in step S2, when the circulating water is seawater, the air leaving the humid and cold zone carries salt droplets. The salt droplets evaporate during the mixing process with the air leaving the dry and cold zone, reducing their volume. The reduced-volume salt droplets are carried by the ambient wind to an area far from the cooling tower and settle after being discharged from the cooling tower.
[0021] Compared with the prior art, the beneficial effects of the present invention are as follows:
[0022] This invention achieves defogging through the combination of dry and wet cooling zones. For seawater circulating water, the combination of dry and wet cooling zones can promote the evaporation of salt droplets during the flow process, avoiding large amounts of salt deposition near the cooling tower. No evaporation loss occurs when the dry cooling zone cools the circulating water, resulting in water-saving benefits. Attached Figure Description
[0023] Figure 1 This is a schematic diagram of the arrangement structure of the present invention;
[0024] Figure 2 This is a schematic diagram of a partial arrangement structure of the present invention;
[0025] Figure 3 This is a schematic diagram of the dry-cooling zone configuration of the present invention. Figure 1 ;
[0026] Figure 4 This is a schematic diagram of the dry-cooling zone configuration of the present invention. Figure 2 ;
[0027] Figure 5 This is a schematic diagram of the dry-cooling zone configuration of the present invention. Figure 3 ;
[0028] Figure 6 This is a schematic diagram of the dry-cooling zone configuration of the present invention. Figure 4 .
[0029] The numbers in the image represent:
[0030] 1. Tower body; 2. Water separator; 3. Water collection tank; 4. Main cooling zone; 41. Wet cooling zone; 42. Dry cooling zone. Detailed Implementation
[0031] The present invention will be further described below with reference to the accompanying drawings and embodiments, which illustrate the above and other technical features and advantages of the present invention. However, the following embodiments are merely preferred embodiments of the present invention and are not exhaustive.
[0032] Example:
[0033] like Figures 1-6 As shown, a salt-controlled demisting natural ventilation cooling tower includes a tower body 1, a water separator 2, and a water collection tank 3. The water separator 2 is located inside the upper part of the tower body 1, and the water collection tank 3 is located at the bottom of the tower body 1. A total cooling zone 4 is located inside the lower part of the tower body 1. The total cooling zone 4 is composed of alternating wet cooling zone 41 and dry cooling zone 42. The wet cooling zone 41 and dry cooling zone 42 are used to change the temperature and humidity of the air flowing through it.
[0034] The wet cooling zone 41 includes a wet cooling zone water distribution pipeline, water spray nozzles, and packing material. The wet cooling zone water distribution pipeline is installed below the water separator 2 via a bracket. Several sets of water spray nozzles are distributed at the bottom of the wet cooling zone water distribution pipeline. The water spray nozzles are used to spray the circulating water in the wet cooling zone water distribution pipeline to form a spray area. The packing material is installed above the water collection tank 3 via a bracket, and the packing material matches the spray area. During cooling, the circulating water enters the wet cooling zone water distribution pipeline and is sprayed onto the surface of the packing material through the water spray nozzles. The circulating water exchanges heat to the ambient air, and the water on the lower surface of the packing material falls naturally into the water collection tank 3.
[0035] The dry cooling zone 42 includes a dry cooling zone water distribution pipeline and a heat exchanger. The dry cooling zone water distribution pipeline is installed below the water separator 2 via a bracket. Several sets of heat exchangers are alternately arranged between the packing material. Each set of heat exchangers is connected to the dry cooling zone water distribution pipeline via a pipe valve assembly. During cooling, circulating water enters the dry cooling zone water distribution pipeline and enters the heat exchanger through the pipe valve assembly. The heat exchanger exchanges heat with the air.
[0036] The area of the dry cooling zone 42 accounts for 10% to 50% of the total area of the cooling zone 4, while the area of the wet cooling zone 41 accounts for 50% to 90% of the total area of the cooling zone 4. Through the design of the area ratio, it can be ensured that the dry cooling zone 42 can generate enough dry hot air under different ambient temperatures and relative humidity. The dry hot air is used to dilute the wet hot air above the wet cooling zone 41, so that the air temperature and moisture content discharged from the cooling tower 1 are lower than those of the air above the wet cooling zone 41, thus suppressing the formation of mist plumes.
[0037] The drain outlet of the heat exchanger is connected to the water collection tank 3 and the water distribution pipeline of the wet and cold zone through a three-way valve. The circulating water enters the water collection tank 3 or the water distribution pipeline of the wet and cold zone through the three-way valve. After the heat exchanger completes one cooling cycle, the circulating water can be sent back into the circulation system according to the selection.
[0038] The arrangement shape of the dry and cold zone 42 includes, but is not limited to, concentric rings, rectangles, triangles, and combinations of concentric rings, rectangles, and triangles.
[0039] The dry cooling zone 42 is a concentric ring, with several dry cooling zones 42 arranged from the inside out with gradually increasing height. Through the ring design, the air mixing uniformity can be improved, and the temperature and moisture content of the air inside the tower can be reduced better.
[0040] The dry cooling zone 42 has a mixed rectangular and triangular configuration, with the rectangular dry cooling zone 42 facing the windward side and the triangular dry cooling zone 42 facing the leeward side. Affected by the ambient wind, a longitudinal vortex is formed at the upper edge of the air inlet on the windward side of the cooling tower 1. The airflow performance in this area deteriorates, resulting in the exhaust gas having the characteristics of high temperature, high humidity, and high droplet volume. Therefore, a larger area of dry cooling zone 42 is arranged on the windward side of the cooling tower 1, which can promote the evaporation of salt droplets and reduce the temperature and humidity of the exhaust gas, thereby achieving salt control and demisting.
[0041] A method for operating a salt-controlled, demisting, natural ventilation cooling tower includes the following steps:
[0042] Step S1, salt control and demisting: When the ambient temperature is below 10℃, 50% to 80% of the circulating water is sent into the heat exchanger through the dry cooling zone water distribution pipeline and valve assembly, and 20% to 50% of the circulating water is sent into the wet cooling zone water distribution pipeline. The wet cooling zone water distribution pipeline sprays the circulating water onto the upper surface of the packing material through the water spray nozzles. After the circulating water flows through the packing material, it is collected in the water collection tank.
[0043] In step S2, ambient air enters both the wet and cold zone 41 and the dry and cold zone 42 from outside the tower body 1. The air rises through the packing material. The air entering the wet and cold zone 41 exchanges heat and mass with the packing material. When the air leaves the wet and cold zone 41, both the temperature and moisture content increase, and droplets are formed.
[0044] When the circulating water is seawater, the air leaving the wet and cold zone 41 carries salt droplets. The salt droplets evaporate during the process of mixing with the air leaving the dry and cold zone 42, and their volume decreases. The reduced-volume salt droplets are discharged from the cooling tower and drift with the ambient wind to an area far away from the cooling tower to settle.
[0045] In step S3, the air entering the dry and cold zone 42 passes upward through the heat exchanger, and the air exchanges heat with the heat exchanger. When the air leaves the dry and cold zone 42, the moisture content remains unchanged, but the temperature rises.
[0046] The air leaving the dry and cold zone 42 and the wet and cold zone 41 mix with each other. The temperature and humidity of the mixed air are lower than those of the air leaving the wet and cold zone 41, thus completely defogging.
[0047] Step S4: When the ambient temperature is 10℃~30℃, 30%~50% of the circulating water is sent into the heat exchanger through the dry cooling zone water distribution pipeline and valve assembly. After heat exchange in the heat exchanger, 0~100% of the circulating water is sent into the wet cooling zone water distribution pipeline for secondary cooling in the wet cooling zone 41.
[0048] Step S5: When the ambient temperature is higher than 30℃, 10% to 30% of the circulating water is sent into the heat exchanger through the dry cooling zone water distribution pipeline and valve assembly. All the circulating water after heat exchange in the heat exchanger is sent into the wet cooling zone water distribution pipeline for secondary cooling in the wet cooling zone 41.
[0049] The above description is merely a preferred embodiment of the present invention and is illustrative rather than restrictive. Those skilled in the art will understand that many changes, modifications, and even equivalents can be made within the spirit and scope defined by the claims of the present invention, all of which will fall within the protection scope of the present invention.
Claims
1. A salt-controlled, demisting, natural ventilation cooling tower, comprising a tower body (1), a water separator (2), and a water collection tank (3), wherein the water separator (2) is disposed inside the upper part of the tower body (1), and the water collection tank (3) is disposed at the bottom of the tower body (1), characterized in that: The tower body 1 has a total cooling zone (4) located at the bottom. The total cooling zone (4) is composed of alternating wet cooling zone (41) and dry cooling zone (42). The wet cooling zone (41) and dry cooling zone (42) are used to change the temperature and humidity of the air flowing through it.
2. The salt-controlled, demisting, natural ventilation cooling tower as described in claim 1, characterized in that, The wet and cold zone (41) includes a wet and cold zone water distribution pipeline, a water spray nozzle and a packing material. The wet and cold zone water distribution pipeline is installed below the water separator (2) by a bracket. Several sets of water spray nozzles are dispersed at the bottom of the wet and cold zone water distribution pipeline. The water spray nozzles are used to spray out the circulating water in the wet and cold zone water distribution pipeline and form a spray area. The packing material is installed above the water collection tank (3) by a bracket and the packing material matches the spray area.
3. The salt-controlled, demisting, natural ventilation cooling tower as described in claim 1, characterized in that, The dry and cold zone (42) includes a dry and cold zone water distribution pipeline and a heat exchanger. The dry and cold zone water distribution pipeline is installed below the water separator (2) by a bracket. Several groups of the heat exchangers are alternately arranged between the packing material. Each group of the heat exchangers is connected to the dry and cold zone water distribution pipeline through a pipe valve assembly.
4. The salt-controlled, demisting, natural ventilation cooling tower as described in claim 1, characterized in that, The area of the dry cooling zone (42) accounts for 10% to 50% of the total area of the cooling zone (4), and the area of the wet cooling zone (41) accounts for 50% to 90% of the total area of the cooling zone (4).
5. A salt-controlled, demisting, natural ventilation cooling tower as described in claim 3, characterized in that, The drain outlet of the heat exchanger is connected to the water collection tank (3) and the water distribution pipeline of the wet and cold zone respectively through a three-way valve. The circulating water enters the water collection tank (3) or the water distribution pipeline of the wet and cold zone through the three-way valve.
6. The salt-controlled, demisting, natural ventilation cooling tower as described in claim 1, characterized in that, The arrangement shape of the dry and cold zone (42) includes, but is not limited to, concentric rings, rectangles, triangles, and combinations of concentric rings, rectangles, and triangles.
7. A salt-controlled, demisting, natural ventilation cooling tower as described in claim 6, characterized in that, The dry and cold zone (42) is a concentric ring, and the height of the several dry and cold zones (42) arranged from the inside to the outside increases step by step.
8. A salt-controlled, demisting, natural ventilation cooling tower as described in claim 7, characterized in that, The dry-cooling zone (42) has a mixed rectangular and triangular configuration, with the rectangular dry-cooling zone (42) facing the windward side and the triangular dry-cooling zone (42) facing the leeward side.
9. A method for operating a salt-controlled, demisting, natural ventilation cooling tower as described in any one of claims 1-8, characterized in that, Includes the following steps: Step S1, salt control and demisting: When the ambient temperature is below 10℃, 50% to 80% of the circulating water is sent into the heat exchanger through the dry cooling zone water distribution pipeline and valve assembly, and 20% to 50% of the circulating water is sent into the wet cooling zone water distribution pipeline. The wet cooling zone water distribution pipeline sprays the circulating water onto the packing surface through water spray nozzles. In step S2, ambient air enters both the wet and cold zone (41) and the dry and cold zone (42) from outside the tower body (1). The air entering the wet and cold zone (41) passes upward through the packing material, and the air and the packing material exchange heat and mass. When the air leaves the wet and cold zone (41), the temperature and moisture content both increase, and droplets are formed. In step S3, the air entering the dry and cold zone (42) passes upward through the heat exchanger, and the air exchanges heat with the heat exchanger. When the air leaves the dry and cold zone (42), the moisture content remains unchanged, but the temperature rises. The air leaving the dry and cold zone (42) and the wet and cold zone (41) mix with each other. The temperature and humidity of the mixed air are lower than those of the air leaving the wet and cold zone (41), thus completely defogging. Step S4: When the ambient temperature is 10℃~30℃, 30%~50% of the circulating water is sent into the heat exchanger through the dry cooling zone water distribution pipeline and valve assembly. After heat exchange in the heat exchanger, 0~100% of the circulating water is sent into the wet cooling zone water distribution pipeline for secondary cooling in the wet cooling zone (41). Step S5: When the ambient temperature is higher than 30°C, 10% to 30% of the circulating water is sent into the heat exchanger through the dry cooling zone water distribution pipeline and valve assembly. All the circulating water after heat exchange in the heat exchanger is sent into the wet cooling zone water distribution pipeline for secondary cooling in the wet cooling zone (41).
10. The working method of a salt-controlled, demisting, natural ventilation cooling tower as described in claim 9, characterized in that, In step S2, when the circulating water is seawater, the air leaving the wet and cold zone (41) carries salt droplets. The salt droplets evaporate during the mixing process with the air leaving the dry and cold zone (42), and their volume decreases. The salt droplets with reduced volume are discharged from the cooling tower and drift with the ambient wind to an area far away from the cooling tower to settle.