A natural ventilation air cooling tower with windbreaks and air inlet spray and its working method

Abstract

The present invention relates to a natural ventilation air-cooling tower with a windbreak and an air inlet spray and a working method thereof. The air-cooling tower includes a tower body, a heat exchanger, a first windbreak, a second windbreak, a spray pipe, and a cooling system. The tower body is provided with a heat exchanger, a first windbreak is provided obliquely on the windward side of the tower body below the heat exchanger, an air inlet A and an air inlet B are provided on the tower body above and below the first windbreak, respectively, a second windbreak is provided obliquely on the bottom of the tower body on the leeward side of the heat exchanger below the heat exchanger, an air inlet C is provided on the tower body above the second windbreak, spray pipes are provided on the upper side of the first windbreak, the upper side of the second windbreak, and the middle of the tower body below the heat exchanger, nozzles are evenly distributed on the spray pipes, and the spray pipes are connected to the cooling system. The present invention cools the air inlet of the air-cooling tower by adding a spray, thereby improving the cooling efficiency of the air-cooling tower, increasing the ventilation volume of the air-cooling tower, and better allowing the spray water to contact with the air to achieve efficient and complete evaporation.

Description

Technical Field

[0001] The invention relates to a natural ventilation air cooling tower with a windproof plate and an air inlet spray and a working method thereof, belonging to the technical field of cooling towers. Background Art

[0002] As a key component of the cold-end system, the performance of a natural draft air-cooling tower significantly impacts the economics and stability of a power plant. A cooling tower with low cooling efficiency will increase the circulating water temperature and reduce the condenser vacuum, leading to a decrease in the operating efficiency of the steam turbine unit and, consequently, the overall cycle thermal efficiency of the unit.

[0003] Natural ventilation air-cooling towers have become increasingly popular in thermal power plants located in arid and water-scarce areas in recent years due to their advantages such as no water consumption, no fans, and low maintenance costs.

[0004] The water used in the cooling tower is the circulating medium. The circulating water absorbs heat from the cooling equipment of the power plant and discharges the heat into the atmosphere through the cooling tower. Natural ventilation air-cooling towers are often used in arid areas (such as the northwest region). Harmon-type natural ventilation air-cooling towers usually place the heat exchanger inside the tower. By creating a density difference between the air inside and outside the tower, the buoyancy force drives the air outside the tower to continuously flow into the tower, exchanging heat with the circulating water in the heat exchanger inside the tower, thereby cooling the circulating water. However, existing natural ventilation air-cooling towers have the following two defects: First, when the ambient temperature is high, the temperature difference between the air and the circulating water in the heat exchanger becomes smaller, and the air cooling effect is poor; second, when the ambient crosswind speed is high, the ventilation volume of the tower is reduced, thereby reducing the heat exchange capacity of the tower and reducing performance. Summary of the Invention

[0005] In response to the shortcomings of the existing technology, the present invention provides a natural ventilation air-cooling tower with windbreaks and air inlet sprays. The air inlet of the air-cooling tower is cooled by adding sprays, thereby improving the cooling efficiency of the cooling tower. The windbreaks on the windward and leeward sides of the tower are used to alleviate the impact of the ambient side wind on the air-cooling tower, thereby increasing the ventilation volume of the air-cooling tower. Moreover, through the cooperation of the spray cooling system and the windbreaks, the spray water can be better brought into contact with the air, thereby achieving efficient and complete evaporation.

[0006] The present invention also provides a method for operating the natural ventilation air cooling tower with windbreaks and air inlet sprays.

[0007] The technical solutions of the present invention are as follows:

[0008] A natural ventilation air cooling tower with windbreaks and air inlet sprays, comprising a tower body, a heat exchanger, a first windbreak, a second windbreak, a spray pipe and a cooling system, wherein:

[0009] There is a heat exchanger inside the tower body. On the windward side of the tower body below the heat exchanger, a first wind deflector is inclined. An air inlet A and an air inlet B are respectively arranged on the tower body above and below the first wind deflector. On the leeward side bottom of the tower body below the heat exchanger, a second wind deflector is inclined. An air inlet C is arranged on the tower body above the second wind deflector. Spray pipes are arranged in the middle of the upper side of the first wind deflector, the upper side of the second wind deflector and the tower body below the heat exchanger. Nozzles are evenly arranged on the spray pipes. The spray pipes are connected to a cooling system.

[0010] Preferably, the cooling system includes a water pump, a water tank and a water supply pipe. The spray pipe is successively connected to the water pump, the water tank and the water supply pipe. A flow meter and a control valve are arranged on the connecting pipe between the spray pipe and the water pump.

[0011] Preferably, both the first wind deflector and the second wind deflector are curved panels. The curved surfaces fit the incoming air streamline, which can greatly reduce the flow resistance brought by the wind deflectors, thereby reducing the influence of the wind deflectors on the incoming air flow field of the cooling tower, and realizing the function of alleviating the influence of the environmental side wind on the air-cooled tower and wind prevention and wind guiding.

[0012] Preferably, the height difference between the bottom of the first wind deflector and the bottom of the tower body is h. h and the height H of the top of the air inlet A on the upper side of the first wind deflector satisfy the following relationship: 0.1H < h < 0.9H. The height of the top of the first wind deflector is the same as the elevation L of the air inlet of the heat exchanger. h is also the height of the air inlet B on the lower side of the first wind deflector. The height of the air inlet A on the upper side of the first wind deflector is H - h.

[0013] [[ID=D12]]Preferably, the vertical height of the second wind deflector is the same as the height of the air inlet C on the leeward side of the tower body. The vertical height M of the second wind deflector and the height H of the top of the air inlet A on the windward side satisfy the following relationship: 0.1H < M < H.

[0014] The first wind deflector and the second wind deflector are arranged at different heights. Part of the incoming air of the tower body enters through the upper part of the first wind deflector and is spray-cooled through the spray pipe. Part of the incoming air enters through the lower part of the first wind deflector. The lower incoming air can be cooled with equal humidity on the back of the first wind deflector, and then continue to rise under the drive of the buoyancy force and contact the spray pipe in the central area of the tower body for secondary cooling. Because the heat exchanger area of the natural draft air-cooled tower is huge and the incoming air in the central area of the tower body is relatively less, such a design can increase the air volume in the central area of the tower and play a certain role in flow equalization.

[0015] When there is a side wind, the incoming air enters through the lower part of the first wind deflector and passes through to the second wind deflector. Since the height of the second wind deflector is lower than that of the first wind deflector, it can prevent the through-flow wind passing through the lower part of the first wind deflector from directly passing out of the tower through the air inlet on the leeward side of the tower body without flowing through the heat exchanger, thereby increasing the air volume in the central area of the tower and also having a certain role in flow equalization.

[0016] Preferably, the nozzle openings of the upper spray pipes of the first wind shield and the second wind shield are upward, and the nozzle arrangement spacing on the upper spray pipe of the first wind shield is smaller than the nozzle arrangement spacing on the upper spray pipe of the second wind shield. When there is a side wind, there is more air distribution at the windward side air inlet A, and the air intake in the center area of ​​the tower is relatively less, and there is also less air distribution at the leeward side air inlet C. The nozzle spacing on the upper spray pipe of the first wind shield is small and the number is large, which can increase the contact area between the spray water and the incoming air, achieve efficient and complete evaporation, and save water to a greater extent while meeting the cooling needs.

[0017] Preferably, the spray pipe arranged on the upper side of the first windbreak plate is parallel to the tangent of the curved surface of the first windbreak plate, and the spray pipe arranged on the upper side of the second windbreak plate is parallel to the tangent of the curved surface of the second windbreak plate, so that the spraying direction and the incoming air flow direction form an angle of approximately 90 degrees, further increasing the contact area between the spraying water and the incoming air.

[0018] Preferably, the spray pipe in the middle of the tower body is parallel to the horizontal plane of the heat exchanger, and the nozzle opening of the spray pipe in the middle of the tower body is downward, forming a countercurrent with the incoming air in the center area of ​​the tower body, which can better increase the contact area between the spray water and the incoming air.

[0019] Preferably, the spray radius r of the tower center spray pipe and the radius R of the heat exchanger satisfy the following relationship: <r<0.8R。

[0020] Working principle: The air inlet spray of the present invention is divided into three zones, specifically, one spray zone on the windward side, one spray zone on the leeward side, and one spray zone in the center area of ​​the tower body. The spray zones can be closed or opened according to the changes in the ambient temperature and the water temperature out of the tower, and the zones can be regulated. When the ambient temperature is not very high, only one zone can be opened (the spraying of two zones can be closed) or two zones can be opened (the spraying of one zone can be closed) to save water loss and water pump power consumption; when the ambient temperature is very high and the cooling capacity of the air-cooling tower is poor, all three spray zones can be opened to better improve the cooling performance of the air-cooling tower.

[0021] The windbreaks of the present invention alter the horizontal air velocity along the tower base, preventing excessively high horizontal air velocity there. This reduces the local pressure at the bottom and prevents hot air from flowing back inside the tower. Furthermore, when horizontally flowing air encounters the windbreaks, its direction of flow changes, with most of the air moving upward along the windbreaks and directly passing through the heat exchanger tube bundles, effectively preventing the formation of drafts at the tower base. The windbreaks increase ventilation within the tower and improve its heat exchange performance.

[0022] The working method of the above-mentioned natural ventilation air cooling tower with wind shield and air inlet spray is as follows:

[0023] (1) When the ambient temperature is between 20°C and 30°C, the spray pipe on the upper side of the first windbreak plate or the spray pipe in the center of the tower body is opened, and the air and the droplets are in direct contact for evaporative cooling, and the cooled air is then exchanged with the heat exchanger;

[0024] (2) When the ambient temperature is higher than 30°, the spray pipe on the upper side of the first wind shield, the spray pipe on the upper side of the second wind shield and the spray pipe in the center of the tower body are opened. Part of the air on the windward side of the tower body enters through the upper part of the first wind shield and is sprayed and evaporated for cooling through the spray pipe. Part of the air enters through the lower part of the first wind shield. The lower air can be isohumidified and cooled with the back of the first wind shield. Then, driven by the buoyancy, it continues to rise and contacts the spray pipe in the center of the tower body for secondary cooling. The air on the leeward side of the tower body enters through the air inlet C on the upper part of the second wind shield and is sprayed and evaporated for cooling through the spray pipe. The cooled air is then heat-exchanged with the heat exchanger.

[0025] The beneficial effects of the present invention are:

[0026] The present invention provides a natural draft air-cooling tower with windbreaks and inlet sprays. The spray cools the tower's inlet air, improving the tower's cooling efficiency. Windbreaks on both the windward and leeward sides of the tower mitigate the effects of ambient crosswinds on the tower, increasing the tower's ventilation rate. Furthermore, the combination of the spray cooling system and windbreaks allows for better contact between the spray water and the air, achieving efficient and complete evaporation. The spray system is divided into three zones and can be controlled by each zone. Spraying can be activated in each zone according to the tower's cooling needs, achieving efficient and water-saving operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a front cross-sectional view of the present invention;

[0028] Figure 2 It is a left side sectional view of the present invention;

[0029] Figure 3 It is a top view of the present invention.

[0030] Among them: 1. Tower body, 2. Heat exchanger, 3. Spray pipe A, 4. Nozzle, 5. Air inlet A, 6. First wind shield, 7. Spray pipe B, 8. Air inlet B, 9. Flow meter, 10. Control valve, 11. Water pump, 12. Water tank, 13. Water supply pipe, 14. Second wind shield, 15. Spray pipe C, 16. Air inlet C. DETAILED DESCRIPTION

[0031] The present invention will be further described below with reference to embodiments and accompanying drawings, but is not limited thereto.

[0032] Example 1:

[0033] like Figure 1-3 As shown in Figure 1-3 , the present invention provides a natural ventilation air cooling tower with a wind protection plate and an inlet air spray, including a tower body 1, a heat exchanger 2, a first wind protection plate 6, a second wind protection plate 14, a spray pipeline, and a cooling system. Among them,

[0034] A heat exchanger 2 is arranged inside the tower body 1. A first wind protection plate 6 is inclinedly arranged on the windward side of the tower body below the heat exchanger 2. An air inlet A5 and an air inlet B8 are respectively arranged on the tower body above and below the first wind protection plate 6. A second wind protection plate 14 is inclinedly arranged at the bottom of the leeward side of the tower body 1 below the heat exchanger 2. An air inlet C16 is arranged on the tower body above the second wind protection plate 14. Spray pipelines B7, C15, and A3 are respectively arranged in the middle of the tower body 1 above the first wind protection plate 6, above the second wind protection plate 14, and below the heat exchanger 2. Nozzles are arranged on the spray pipelines B7, C15, and A3. The spray pipelines B7, C15, and A3 are connected to a cooling system. The upper and lower sides of the first wind protection plate and the second wind protection plate can be fixed inside the tower body through structures such as steel ropes or steel pipes to achieve the stability of the inclined setting.

[0035] The cooling system includes a water pump 11, a water tank 12, and a water replenishing pipe 13. The spray pipelines B7, C15, and A3 are respectively connected to the water pump 11, the water tank 12, and the water replenishing pipe 13 in sequence. Flow meters 9 and control valves 10 are arranged on the connecting pipelines between the spray pipelines B7, C15, and A3 and the water pump.

[0036] Both the first wind protection plate 6 and the second wind protection plate 14 are curved plates. The curved surface fits the incoming air streamline, which can greatly reduce the flow resistance brought by the wind protection plate, thereby reducing the influence of the wind protection plate on the incoming air flow field of the cooling tower, achieving the effect of alleviating the influence of the environmental side wind on the air cooling tower and guiding the wind, and a water collecting trough can be arranged below the wind protection plate to collect the unevaporated water droplets that drip.

[0037] The height difference between the bottom of the first wind protection plate 6 and the bottom of the tower body 1 is h. h and the height H of the top of the air inlet A5 on the upper side of the first wind protection plate satisfy the following relationship: 0.1H < h < 0.9H. The height of the top of the first wind protection plate 6 is the same as the elevation L of the air inlet of the heat exchanger 2. h is also the height of the air inlet B on the lower side of the first wind protection plate. The height of the air inlet A on the upper side of the first wind protection plate is H - h.

[0038] The vertical height of the second wind protection plate 14 is the same as the height of the air inlet C16 on the leeward side of the tower body. The vertical height M of the second wind protection plate 14 and the height H of the top of the air inlet A5 on the windward side satisfy the following relationship: 0.1H < M < H.

[0039] The first windbreak 6 and the second windbreak 14 are arranged one high and one low. Part of the tower air enters through the upper part of the first windbreak and is spray-cooled through the spray pipe, while part of the air enters through the lower part of the first windbreak. The lower air can be cooled by isohumidity with the back of the first windbreak, and then continue to rise under the drive of buoyancy and contact the spray pipe in the center area of ​​the tower body for secondary cooling. Because the heat exchanger area of ​​the natural ventilation air cooling tower is huge, the air intake in the center area of ​​the tower body is relatively small. This design can increase the air volume in the center area of ​​the tower and play a certain flow balancing role.

[0040] When there is a crosswind, the wind enters through the lower part of the first wind shield and passes through the hall to the second wind shield. Since the height of the second wind shield is lower than that of the first wind shield, it can prevent the cross-wind passing through the lower part of the first wind shield from directly passing through the air inlet on the leeward side of the tower body and out of the tower without flowing through the heat exchanger, thereby increasing the air volume in the center area of ​​the tower and also having a certain flow equalization effect.

[0041] The spray pipe B7 arranged on the upper side of the first windbreak 6 is parallel to the tangent of the curved surface of the first windbreak, and the spray pipe C15 arranged on the upper side of the second windbreak 14 is parallel to the tangent of the curved surface of the second windbreak, so that the spraying direction and the incoming air flow direction form an angle of approximately 90 degrees, further increasing the contact area between the spraying water and the incoming air.

[0042] The spray radius r of the tower center spray pipe A3 and the radius R of the heat exchanger 2 satisfy the following relationship: <r<0.8R。

[0043] Working principle: The air inlet spray of the present invention is divided into three zones, specifically, one spray zone on the windward side, one spray zone on the leeward side, and one spray zone in the center area of ​​the tower body. The spray zones can be closed or opened according to the changes in the ambient temperature and the water temperature out of the tower, and the zones can be regulated. When the ambient temperature is not very high, only one zone can be opened (the spraying of two zones can be closed) or two zones can be opened (the spraying of one zone can be closed) to save water loss and water pump power consumption; when the ambient temperature is very high and the cooling capacity of the air-cooling tower is poor, all three spray zones can be opened to better improve the cooling performance of the air-cooling tower.

[0044] The windbreaks of the present invention alter the horizontal air velocity along the tower base, preventing excessively high horizontal air velocity there. This reduces the local pressure at the bottom and prevents hot air from flowing back inside the tower. Furthermore, when horizontally flowing air encounters the windbreaks, its direction of flow changes, with most of the air moving upward along the windbreaks and directly passing through the heat exchanger tube bundles, effectively preventing the formation of drafts at the tower base. The windbreaks increase ventilation within the tower and improve its heat exchange performance.

[0045] The working method of the above-mentioned natural ventilation air cooling tower with wind shield and air inlet spray is as follows:

[0046] (1) When the ambient temperature is between 20°C and 30°C, the spray pipe B7 on the upper side of the first wind shield or the spray pipe A3 in the center of the tower body is opened. The air and the droplets are in direct contact for evaporative cooling, and the cooled air is then exchanged with the heat exchanger.

[0047] (2) When the ambient temperature is higher than 30°, the spray pipe B on the upper side of the first wind shield, the spray pipe A on the upper side of the second wind shield and the spray pipe C in the center of the tower body are opened. Part of the air on the windward side of the tower body enters through the upper part of the first wind shield and is sprayed and evaporated and cooled through the spray pipe B. Part of the air enters through the lower part of the first wind shield. The lower air can be isohumidified and cooled with the back of the first wind shield. Then, driven by the buoyancy, it continues to rise and contacts the spray pipe A in the center area of ​​the tower body for secondary cooling. The air on the leeward side of the tower body enters through the air inlet C on the upper part of the second wind shield and is sprayed and evaporated and cooled through the spray pipe C. The cooled air is then heat-exchanged with the heat exchanger.

[0048] Example 2:

[0049] A natural ventilation air-cooling tower with windbreaks and air inlet sprays has a structure as described in Example 1, except that the nozzles 4 of the spray pipes on the upper sides of the first windbreak 6 and the second windbreak 14 open upward, and the nozzle arrangement spacing on the spray pipe on the upper side of the first windbreak 6 is smaller than the nozzle arrangement spacing on the spray pipe on the upper side of the second windbreak. When there is a side wind, more air is distributed at the windward side air inlet A, and the air inlet in the center area of ​​the tower is relatively less, and the air distribution at the leeward side air inlet C is also less. The nozzles on the spray pipe on the upper side of the first windbreak are closely spaced and numerous, which can increase the contact area between the spray water and the incoming air, achieve efficient and complete evaporation, and save water to a greater extent while meeting the cooling requirements.

[0050] Example 3:

[0051] A natural ventilation air-cooling tower with a windbreak and an air inlet spray has a structure as described in Example 1, except that the spray pipe in the middle of the tower body 1 is parallel to the horizontal plane of the heat exchanger, and the nozzle opening of the spray pipe in the middle of the tower body is downward, forming a countercurrent with the air inlet in the center area of ​​the tower body, which can better increase the contact area between the spray water and the air inlet.

Claims

1. A natural ventilation air cooling tower with windbreaks and air inlet sprays, characterized in that: It includes a tower body, a heat exchanger, a first wind baffle, a second wind baffle, a spray pipe and a cooling system. Among them, a heat exchanger is arranged inside the tower body. A first wind baffle is obliquely arranged on the windward side of the tower body below the heat exchanger. An air inlet A and an air inlet B are respectively arranged on the tower body above and below the first wind baffle. A second wind baffle is obliquely arranged at the bottom of the leeward side of the tower body below the heat exchanger. An air inlet C is arranged on the tower body above the second wind baffle. Spray pipes are arranged in the middle of the tower body above the first wind baffle, above the second wind baffle and below the heat exchanger. Nozzles are evenly arranged on the spray pipes. The spray pipes are connected to a cooling system; The cooling system includes a water pump, a water tank and a water replenishing pipe. The spray pipes are successively connected to the water pump, the water tank and the water replenishing pipe. A flow meter and a control valve are arranged on the connecting pipe between the spray pipes and the water pump; The spray pipe arranged above the first wind baffle is parallel to the tangent of the curved surface of the first wind baffle, and the spray pipe arranged above the second wind baffle is parallel to the tangent of the curved surface of the second wind baffle.

2. The natural ventilation air cooling tower with windbreaks and air inlet sprays according to claim 1, characterized in that: Both the first wind baffle and the second wind baffle are curved panels.

3. The natural ventilation air cooling tower with windbreaks and air inlet sprays according to claim 2, characterized in that: The height difference between the bottom of the first wind baffle and the bottom of the tower body is h. h and the top height H of the air inlet A on the upper side of the first wind baffle satisfy the following relationship: 0.1H < h < 0.9H. The top height of the first wind baffle is consistent with the elevation L of the air inlet of the heat exchanger.

4. The natural ventilation air cooling tower with windbreaks and air inlet sprays according to claim 3, characterized in that: The vertical height of the second wind baffle is consistent with the height of the air inlet C on the leeward side of the tower body. The vertical height M of the second wind baffle and the top height H of the air inlet A on the windward side satisfy the following relationship: 0.1H < M < H.

5. The natural ventilation air cooling tower with windbreaks and air inlet sprays according to claim 2, characterized in that: The nozzles of the spray pipes on the upper sides of the first wind baffle and the second wind baffle open upward. The nozzle arrangement spacing on the spray pipe on the upper side of the first wind baffle is smaller than the nozzle arrangement spacing on the spray pipe on the upper side of the second wind baffle.

6. The natural ventilation air cooling tower with windbreaks and air inlet sprays according to claim 5, characterized in that: The spray pipe in the middle of the tower body is parallel to the horizontal plane of the heat exchanger. The nozzles of the spray pipe in the middle of the tower body open downward.

7. The natural ventilation air cooling tower with windbreaks and air inlet sprays according to claim 6, characterized in that: The spray radius r of the spray pipe at the center of the tower body and the radius R of the heat exchanger satisfy the following relationship: 0 < r < 0.8R.

8. A method for operating a natural ventilation air cooling tower with windbreaks and air inlet sprays as claimed in claim 6, characterized in that: The steps are as follows: (1) When the ambient temperature is between 20 - 30 °C, open the spray pipe on the upper side of the first wind baffle or the spray pipe at the center of the tower body. The air directly contacts the droplets for evaporative cooling. The cooled incoming air exchanges heat with the heat exchanger; (2) When the ambient temperature is higher than 30 °C, open the spray pipe on the upper side of the first wind baffle, the spray pipe on the upper side of the second wind baffle and the spray pipe at the center of the tower body. Part of the incoming air on the windward side of the tower body enters through the upper part of the first wind baffle and is spray-evaporatively cooled through the spray pipe. Part of it enters through the lower part of the first wind baffle. The lower incoming air can be cooled isohumidly with the back of the first wind baffle, and then continues to rise under the drive of buoyancy and contacts the spray pipe in the central area of the tower body for secondary cooling. The air on the leeward side of the tower body enters through the air inlet C in the upper part of the second wind baffle and is spray-evaporatively cooled through the spray pipe. The cooled incoming air exchanges heat with the heat exchanger.

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