A control method and system for preventing freezing of a cooling tower in winter

Abstract

This invention relates to the field of cooling towers, and more particularly to a control method and system for winter antifreeze of cooling towers. It sets multiple temperature thresholds to control the unfolding height of the curtains in the upper and lower windbreak systems, respectively. Dynamic compensation and correction are performed on the target shielding height of the corresponding curtains. During the raising and lowering of the segmented windbreak components, if the deviation exceeds a preset threshold, it is determined that the curtain is misaligned, and deceleration, correction, stopping operation, or alarm operations are executed according to the degree of deviation. The system provides guidance during curtain raising and lowering and provides wind-resistant support when stationary to prevent the curtains from swaying or flapping in the wind. Advantages of this invention: It adopts an independently driven upper and lower segmented windbreak design. The lower windbreak unfolds first, prioritizing the shielding of the bottom area most prone to icing; the upper windbreak unfolds segment by segment from bottom to top, blocking cold air from the bottom up, conforming to the physical characteristic of cold air sinking, achieving optimal antifreeze effect with minimal shielding area.

Description

Technical Field

[0001] This invention relates to the field of cooling towers, and more particularly to a control method and system for preventing cooling towers from freezing in winter. Background Technology

[0002] In low-temperature winter conditions, cooling tower vents are highly susceptible to severe icing. Icing gradually clogs the air intake, increasing fan energy consumption, reducing cooling efficiency, and in severe cases, even threatening the structural safety of the tower. Therefore, effectively preventing icing in cooling towers during winter operation has long been a challenging technical problem in this field.

[0003] Currently, the antifreeze measures used in the industry mainly include intermittent operation of fans, electric heat tracing, and installation of fixed wind deflectors. However, all of the above methods have obvious shortcomings: frequent start-stop of fans will affect the life of the equipment and the temperature control accuracy is poor; electric heat tracing consumes a lot of energy and has high operating costs; fixed wind deflectors cannot flexibly adjust the ventilation area according to changes in air temperature, which can easily lead to excessive insulation or insufficient antifreeze.

[0004] In recent years, solutions using liftable windbreak curtains have emerged, adjusting the ventilation area by raising and lowering a single curtain unit. However, this type of solution still has the following problems: (1) Adjust the coarseness of the grain.

[0005] The overall control of a single curtain makes it difficult to strike a balance between ensuring minimum ventilation requirements and achieving optimal antifreeze effect, and it cannot make fine adjustments based on the physical characteristics of cold air sinking and the lower air intake being greater than the upper air intake.

[0006] (2) Lack of an effective synchronous correction mechanism.

[0007] During long-term operation, single roller shutter machines are prone to "deviation" due to asynchronous lifting on both sides of the curtain, which affects the sealing effect and may even cause equipment jamming. Existing systems lack online monitoring and automatic deviation correction methods.

[0008] (3) Poor wind resistance.

[0009] Existing windproof curtains are prone to swaying and flapping under strong wind conditions, which not only affects the sealing performance but also shortens the service life of the curtain. Summary of the Invention

[0010] The purpose of this invention is to provide a control method and system for winter antifreeze of cooling towers, to solve the problems of coarse antifreeze adjustment granularity, lack of synchronous correction mechanism, and poor wind resistance in the prior art. Through the design of independently driven wind curtains in upper and lower segments, combined with temperature graded control and wind speed compensation correction, the ventilation area can be finely adjusted; the curtain body attitude sensor array realizes synchronous monitoring of lifting and lowering and automatic correction; and the wind baffle array provides guidance and wind resistance support, significantly improving the stability, reliability and energy-saving effect of the system.

[0011] To achieve the above objectives, the present invention provides the following technical solution: A method for controlling the freezing of cooling towers in winter includes: S1. According to the ambient temperature, the temperature is controlled in stages. Multiple temperature thresholds are set to control the unfolding height of the curtain of the upper windproof curtain system (4) and the curtain of the lower windproof curtain system (3) respectively, so as to adjust the ventilation area of ​​the ventilation opening (2) in stages. S2. Dynamically compensate and correct the target occlusion height of the corresponding curtain based on wind speed and direction signals. S3. During the lifting and lowering of the segmented windbreak curtain assembly, the height deviation of the left and right sides of the corresponding curtain is monitored in real time. When the deviation exceeds the preset threshold, it is judged that the curtain is misaligned, and deceleration, correction, stop operation or alarm operation is performed according to the degree of deviation. S4. Multiple sets of vertical windbreak bars arranged on both sides of the curtain provide guidance when the curtain is raised and lowered, and provide wind-resistant support when stationary, to prevent the curtain from swinging or flapping in the wind.

[0012] In S1, tiered regulation specifically includes: When the ambient temperature T > temperature threshold T1, the curtains of the upper windshield curtain system (4) and the lower windshield curtain system (3) are completely retracted. When the temperature threshold T2 < ambient temperature T ≤ temperature threshold T1, the curtain of the lower windshield curtain system (3) unfolds from top to bottom to block the lower half of the ventilation opening (2), while the curtain of the upper windshield curtain system (4) remains folded up. When the temperature threshold T3 < ambient temperature T ≤ temperature threshold T2, the curtain of the upper windshield curtain system (4) unfolds from bottom to top, and the upper part of the shielding height is increased linearly or in stages according to the degree of temperature drop. When the ambient temperature T ≤ temperature threshold T3, the curtain of the upper windshield curtain system (4) is unfolded to the maximum design shielding height, leaving only the minimum ventilation gap; in: Multiple temperature thresholds include temperature threshold T1, temperature threshold T2, and temperature threshold T3, and temperature threshold T1 > temperature threshold T2 > temperature threshold T3.

[0013] In S2, the target occlusion height of the corresponding curtain is dynamically compensated and corrected based on wind speed and direction signals, specifically including: Real-time wind speed and direction signals are collected. When the wind speed exceeds the preset wind speed threshold and the wind direction is directly facing the ventilation opening (2), the target shading height corresponding to the current temperature is dynamically adjusted upward according to the wind speed. The adjustment range is positively correlated with the wind speed value to offset the risk of icing caused by the aggravated wind cooling effect.

[0014] In S3, deceleration, correction, shutdown, or alarm operations are performed based on the degree of deviation. Specifically, these include: Metal sensor plates are evenly spaced on the left and right edges of the curtain. Magnetic proximity switches are installed on the fixed guide rails on the left and right sides of the curtain. Each metal sensor plate generates a pulse when it passes the magnetic proximity switch. The pulse counter is accumulated. When the curtain is raised or lowered, the position and deviation are determined by counting pulses of a magnetic proximity switch, specifically including: S31. Curtain position calculation: (1) The height of the left side curtain is expressed as: Left side curtain height HL = counter L × hole spacing; in: The aperture spacing is the distance between adjacent metal induction plates, in mm; The counter L represents the cumulative number of pulses detected by the left-side magnetic proximity switch; The height of the left-side curtain, HL, is in mm; (2) The height of the right-side curtain is expressed as: Right side curtain height HR = counter R × hole spacing; in: The counter R represents the cumulative number of pulses detected by the magnetic proximity switch on the right, in units of pulses. (3) Deviation, expressed as: ΔH = |HL - HR|; ΔH is the height deviation between the left and right sides of the curtain, in mm; S32. Correction Judgment: When ΔH ≤ the first threshold H1, the curtain height deviation is determined to be normal; When the first threshold H1 < ΔH ≤ the second threshold H2, it is determined that the curtain is slightly misaligned. At this time, the corresponding automatic roller shutter machine running speed is reduced, or the corresponding automatic roller shutter machine is controlled to perform a preset small-amplitude reciprocating lifting and lowering motion to try to automatically correct the deviation. When ΔH > the second threshold H2, it is determined that the curtain is seriously misaligned, and the corresponding automatic rolling shutter machine is immediately stopped and an audible and visual alarm is issued.

[0015] In S4, multiple sets of vertical windbreaks arranged on both sides of the curtain provide guidance when the curtain is raised or lowered, and provide wind-resistant support when stationary. Specifically, they include: During the raising and lowering of the curtain, each set of windbreak rods constrains the direction of movement of the curtain to prevent the curtain from shifting laterally or twisting. When the curtain is stationary, when the wind acts on the curtain, the wind pressure is transmitted through the curtain to multiple sets of vertical windbreak bars, and then distributed by the windbreak bars to the tower foundation, so that the curtain remains stable in the wind and avoids large swings or slaps.

[0016] A control system for winter antifreeze of a cooling tower includes a segmented windbreak assembly, which is installed on the outside of the ventilation opening (2) of the cooling tower (1); a metal crossbeam (9) is fixedly installed in the middle part of the ventilation opening (2); The segmented windshield assembly includes a lower windshield system (3) and an upper windshield system (4), and a windshield bar array. The lower windshield curtain system (3) is installed above the metal beam (9). The curtain of the lower windshield curtain system (3) unfolds from top to bottom to adjust the ventilation area of ​​the lower half of the vent (2). The upper windshield curtain system (4) is installed below the metal crossbeam (9). The curtain of the upper windshield curtain system (4) unfolds from bottom to top to adjust the ventilation area of ​​the upper part of the vent. The windbreak bar array includes several sets of windbreak bars spaced at intervals along the horizontal direction of the ventilation opening (2). Each set of windbreak bars is parallel to each other. Each set of windbreak bars includes two parallel outer windbreak metal bars (10a) and inner windbreak metal bars (10b). The outer windbreak metal bars (10a) and inner windbreak metal bars (10b) are arranged alternately. The curtain passes through the gap between each set of outer windbreak metal bars (10a) and inner windbreak metal bars (10b) to form a wave shape. The upper and lower ends of each set of windbreak bars are fixed to the pre-embedded parts of the cooling tower (1) foundation.

[0017] The vertical distance between the roller of the upper windproof curtain system (4) and the roller of the lower windproof curtain system (3) is 30~50cm, and the curtain of the upper windproof curtain system (4) and the curtain of the lower windproof curtain system (3) have an overlapping area of ​​15~25cm in their range of motion.

[0018] The center-to-center spacing of each set of windbreak bars is 150~200mm, which is greater than the maximum diameter of the roller shutter when it is rolled up; Each set of windbreak bars is a metal round bar with a diameter of 25~40mm or a metal square tube with an equivalent cross section, and its height extends through the entire ventilation opening (2). In the windbreak bar array, the center distance between adjacent groups of windbreak bars is 1 to 2 meters.

[0019] It also includes a multi-parameter sensing module and a control unit, including at least an ambient temperature sensor for monitoring ambient temperature, a wind speed and direction sensor for monitoring wind speed and direction, and a curtain attitude sensing array for monitoring the curtain's unfolding attitude. The curtain attitude sensing array includes multiple position or displacement sensors spaced along the active edge of the curtain, used to provide real-time feedback of height or displacement information at different points on the edge of the curtain. The control unit is connected to the multi-parameter sensing module, the magnetic induction proximity switch, the bottom-opening automatic roller shutter, and the top-opening automatic roller shutter, respectively.

[0020] The metal beam (9) has reinforcing ribs at the bottom or side to enhance the structural rigidity of the metal beam; The lower windshield curtain system (3) is driven by a bottom-opening automatic roller shutter machine; The upper windproof curtain system (4) is driven by an upper-opening automatic roller shutter machine.

[0021] Compared with the prior art, the beneficial effects of the present invention are: 1. Cooling towers exhibit a distinct height distribution of air intake, with significantly higher airflow at the bottom than at the top, resulting in a pronounced cold air sinking effect. This invention employs a segmented, independently driven windbreak curtain design. The control logic is as follows: the lower windbreak curtain unfolds first, prioritizing the shielding of the bottom area most prone to icing; the upper windbreak curtain unfolds segment by segment from bottom to top, blocking cold air from the bottom up. This control strategy aligns with the physical characteristic of cold air sinking, achieving optimal antifreeze effect with minimal shielding area. Compared to existing single-curtain overall control schemes, this invention reduces ineffective shielding area by approximately 30%-50%, correspondingly reducing fan energy consumption and resulting in significant energy savings. 2. The upper and lower rollers are centrally installed near the metal beam in the middle of the ventilation opening. When the curtain is rolled up, it is stored in the middle area of ​​the ventilation opening, which has the following multiple advantages: (1) It is far away from the water splash area, which avoids the curtain being in contact with the humid environment for a long time, effectively preventing the curtain from being corroded and moldy, and extending its service life; (2) All mechanical and electrical components (roller curtain machine, motor, sensor, control unit, etc.) are centrally arranged in the easily accessible middle area, which facilitates daily inspection, maintenance and replacement, and reduces the difficulty of installation and operation and maintenance costs; (3) It avoids setting up large equipment at the top or bottom of the ventilation opening, optimizes the use of space, does not affect the uniform distribution of airflow, and does not occupy the maintenance passage. 3. Through the segmented curtain design with independent upper and lower drive, combined with multi-parameter closed-loop control of ambient temperature, wind speed and wind direction, the ventilation area of ​​the ventilation opening is adjusted in a step-by-step and refined manner: (1) Multiple temperature thresholds (T1, T2, T3) are set to achieve graded control and adopt different shielding strategies in different temperature ranges; (2) A wind speed compensation correction mechanism is introduced. When the wind speed exceeds the preset threshold and the wind direction is directly facing the ventilation opening, the target shielding height is dynamically adjusted according to the wind speed to effectively offset the additional icing risk caused by the wind cooling effect; (3) The control unit can flexibly adjust the control parameters according to the actual operating data, which is suitable for different regional climate conditions and cooling tower models, and has good adaptability and scalability. 4. A windbreak bar array structure was designed to transform the traditional planar windbreak curtain into a multi-point supported guide structure: (1) Each windbreak bar consists of two parallel vertical metal bars through which the curtain passes to form a sliding guide rail structure, providing precise guidance when the curtain is raised and lowered, and providing wind-resistant support when stationary; (2) When strong winds act on the curtain, the wind pressure is transmitted through the curtain to multiple windbreak bars, and then dispersed by the windbreak bars to the tower foundation, avoiding stress concentration; (3) According to actual measurements, using the windbreak bar array structure of this invention, under high wind speed conditions, the curtain swing amplitude is reduced from about 300mm without windbreak bars to less than 50mm, and the swing amplitude is reduced by more than 80%, which enhances the stability and sealing of the system under strong wind conditions and effectively extends the service life of the curtain; 5. A curtain posture online monitoring and graded correction alarm mechanism was designed: (1) Metal induction plates were set at equal intervals on the left and right edges of the curtain, and pulse counting was achieved in conjunction with magnetic induction proximity switches to more accurately calculate the real-time height and synchronization deviation of the left and right sides of the curtain; (2) Two levels of deviation thresholds were set (H1=20mm, H2=50mm): when there is slight deviation, the machine will automatically decelerate or perform small reciprocating motion to try to self-correct; when there is serious deviation, the machine will stop immediately and sound and light alarms will be set to avoid equipment damage; (3) This mechanism can provide timely warning and locate mechanical transmission faults (such as roller bending, curtain jamming, motor asynchrony, etc.), avoiding overall functional failure or equipment damage caused by single point faults, and significantly improving the operational reliability of the system; 6. By adopting mature and reliable components such as rolling shutters, proximity switches, and metal rods, and through an optimized combination of control logic and mechanical structure, this invention has significant advantages in terms of initial investment and long-term operating costs, and is easy to promote and apply in new cooling tower projects and renovation projects of existing cooling towers. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the control system structure for winter antifreeze of a cooling tower.

[0023] Figure 2 It is a structural installation diagram of a curtain system with a wind deflector.

[0024] Figure 3 This is a side view of the curtain system structure with wind deflectors.

[0025] Figure 4 This is a control flowchart for winter freeze protection of cooling towers.

[0026] In the diagram: 1. Cooling tower; 2. Ventilation opening; 3. Lower windshield curtain system; 4. Upper windshield curtain system; 5a. Magnetic induction proximity switch on the left side of the upper windshield curtain; 5b. Magnetic induction proximity switch on the right side of the upper windshield curtain; 5c. Magnetic induction proximity switch on the left side of the lower windshield curtain; 5d. Magnetic induction proximity switch on the right side of the lower windshield curtain; 6. Control cabinet; 7. Outdoor temperature detection instrument; 8. Wind speed and direction detection instrument; 9. Metal crossbeam; 10b. Inner windshield rod; 11. Metal induction plate; 10a. Outer windshield rod; 12. Curtain; 21. Climber; 22. Climbing rod; 31. Downward-opening automatic curtain rolling machine; 32. Lower windshield curtain end shaft; 33. Lower windshield curtain power roller; 42. Upper windshield curtain end shaft; 43. Upper windshield curtain power roller; 50. Main steel cable; 51. Main load-bearing roller; 52. Load-bearing reversing roller; 53. Suspension steel cable. Detailed Implementation

[0027] The present invention will now be described in detail with reference to the accompanying drawings, but it should be noted that the implementation of the present invention is not limited to the following embodiments.

[0028] The following embodiments are implemented based on the technical solution of the present invention, providing detailed implementation methods and specific operation processes. However, the scope of protection of the present invention is not limited to the following embodiments. Unless otherwise specified, the methods used in the following embodiments are conventional methods.

[0029] Example 1:

[0030] See Figure 1-3 A control system for winter antifreeze of a cooling tower includes a segmented windbreak assembly, a multi-parameter sensing module, a control unit, and at least an ambient temperature sensor for monitoring ambient temperature, a wind speed and direction sensor for monitoring wind speed and direction, and a curtain posture sensor array for monitoring the unfolding posture of the curtain. The segmented windbreak assembly is installed on the outside of the ventilation opening (2) of the cooling tower (1). A metal crossbeam (9) is fixedly installed in the middle of the ventilation opening (2), which is made of hot-dip galvanized steel or 304 stainless steel, with a cross-sectional size of (80~120mm)×(80~120mm), spanning the entire width of the ventilation opening and being firmly fixed to the tower structure. The bottom or side of the metal crossbeam (9) is connected with reinforcing ribs to enhance the structural rigidity of the metal crossbeam.

[0031] 1. Segmented windbreak curtain assembly: The segmented windshield assembly includes a lower windshield system (3), an upper windshield system (4), and a windshield bar array, as follows: (1) Lower windshield curtain system (3): The lower windshield curtain system (3) adopts a bottom-opening automatic roller shutter machine, and its top roller (i.e., the end 32 of the lower windshield curtain) is installed 15~30cm above the metal crossbeam (9). The curtain of the lower windshield curtain system (3) unfolds from top to bottom to adjust the ventilation area of ​​the lower half of the ventilation opening (2).

[0032] See Figure 2 The lower windshield end shaft (32) is used to support the end of the curtain of the lower windshield system (3) and keep the curtain of the lower windshield system (3) flat. The lower windshield power roller (33) is an active rotating component. It drives the curtain of the lower windshield system (3) to rotate around the lower windshield power roller (33) to realize the winding and unfolding. The lower windshield end shaft (32) and the lower windshield power roller (33) are set parallel to each other. The curtain of the lower windshield system (3) is wrapped around the lower windshield power roller (33). The power roller (33) slides up and down along the climbing rod (22) through the climber (21). When the power roller rotates, it drives the curtain of the lower windshield system (3) to move. The lower windshield end shaft (32) is fixed. The lower windshield end shaft (32) and the lower windshield power roller (33) work together to complete the winding or unfolding of the curtain of the lower windshield system (3).

[0033] (2) Upper windshield curtain system (4): The upper windproof curtain system (4) adopts an upward-opening automatic roller shutter machine. Its bottom roller (i.e., the upper windproof curtain power roller 43) is installed and fixed 15~30cm below the metal crossbeam (9). The curtain of the upper windproof curtain system (4) unfolds from bottom to top to adjust the ventilation area of ​​the upper part of the ventilation opening.

[0034] See Figure 2 The relationship between the upper windshield end shaft (42) and the upper windshield power roller (43): The upper windshield end shaft (42) is used to support the end of the curtain of the upper windshield system (4). The upper windshield power roller (43) is an active drive component. The upper windshield end shaft (42) and the upper windshield power roller (43) are arranged in parallel. When the power roller rotates, it transmits force to the hanging steel cable (53) to drive the upper windshield end shaft (42) to slide up and down, and together complete the lifting and lowering action of the curtain of the upper windshield system (4).

[0035] (3) Roll arrangement: The vertical distance between the center lines of the lower windshield end shaft (32) and the upper windshield power roller (43) is 30~50cm, and the corresponding curtain movement range has an overlapping area of ​​15~25cm, ensuring that the curtain of the lower windshield system (3) and the curtain of the upper windshield system (4) can seamlessly cover the entire height of the ventilation opening when fully unfolded.

[0036] 2. Windshield array: The windbreak bar array includes several groups of windbreak bars spaced at intervals along the horizontal direction of the ventilation opening (2), with each group of windbreak bars parallel to each other. Each group of windbreak bars includes two parallel outer windbreak metal bars (10a) and inner windbreak metal bars (10b), which are arranged alternately. The curtain passes through the gap between each group of outer windbreak metal bars (10a) and inner windbreak metal bars (10b) to form a wave shape for wind resistance and guidance. The center-to-center distance of each group of windbreak bars is 150~200mm, which is greater than the maximum diameter when the curtain is rolled up. Each group of windbreak bars is a metal round bar with a diameter of 25~40mm or a metal square tube with an equivalent cross section. The upper and lower ends of each group of windbreak bars are fixed to the embedded parts of the cooling tower (1) foundation, and the height extends through the entire ventilation opening (2). The center-to-center distance between adjacent groups of windbreak bars is 1~2 meters. The curtain fabric has reinforced edging, with embedded sliding rings or wear-resistant sliders. During installation, the curtain fabric passes between the two wind deflectors in each group, forming a sliding guide rail structure. 3. Multi-parameter sensing module: The multi-parameter sensing module includes an ambient temperature sensor, a wind speed and direction sensor, and a curtain attitude sensing array. The curtain attitude sensing array includes multiple position / displacement sensors spaced along the lower edge or sides of the curtain, used to monitor the absolute height or relative displacement of the curtain at different positions in real time.

[0037] 4. Curtain attitude sensor array: Metal sensor plates 11 are evenly spaced on both sides of the curtain edge, with a spacing (hole distance) of 100mm between adjacent metal sensor plates 11. Magnetic proximity switches 5 are installed on the fixed guide rails on both sides of the curtain, with each magnetic proximity switch 5 installed at the starting end of the curtain lifting stroke.

[0038] During the corresponding curtain raising and lowering process, when the metal sensor 11 moves with the corresponding curtain past the magnetic proximity switch 5, the magnetic proximity switch 5 detects the metal sensor 11 and generates a pulse signal, which is then accumulated by a pulse counter. The corresponding curtain height and synchronism on both sides are calculated by counting the pulses.

[0039] 5. Control Unit: The control unit is a PLC. The PLC's signal input is connected to a multi-parameter sensing module, and its control output is connected to the drive motors of both the bottom-opening and top-opening automatic roller shutters. The PLC calculates and outputs target height commands for the upper and lower curtains based on ambient temperature, wind speed, and preset strategies. It also implements lifting control and deviation alarms based on feedback signals from the curtain attitude sensor array.

[0040] See Figure 4 A method for controlling the freezing of cooling towers in winter, comprising: S1, graded regulation; According to the ambient temperature, the system is graded and controlled, and multiple temperature thresholds are set to control the unfolding height of the curtain of the upper windproof curtain system (4) and the curtain of the lower windproof curtain system (3) respectively, so as to adjust the ventilation area of ​​the ventilation opening (2) in stages. The temperature thresholds are set as T1=4℃, T2=-8℃, and T3=-20℃. The tiered control specifically includes: When the ambient temperature T>4℃, the curtains of the upper windshield curtain system (4) and the lower windshield curtain system (3) are completely retracted, and the ventilation openings are fully open.

[0041] When -8℃ < ambient temperature T≤4℃, the curtain of the lower windshield curtain system (3) unfolds from top to bottom to cover the lower half of the ventilation opening (2), while the curtain of the upper windshield curtain system (4) remains folded up.

[0042] When -20℃ < ambient temperature T≤ -8℃, the curtain of the lower windshield curtain system (3) remains fully extended, and the curtain of the upper windshield curtain system (4) unfolds from bottom to top, and the upper part of the shielding height increases linearly according to the degree of temperature drop: when T=-10℃, the upper windshield curtain unfolds to 30% of the height of the upper part of the ventilation opening; when T=-15℃, it unfolds to 50%.

[0043] When the ambient temperature T≤-20℃, the curtain of the upper windproof curtain system (4) is unfolded to the maximum design blocking height (e.g., 70% of the height of the upper ventilation opening), leaving only a minimum ventilation gap of 30%.

[0044] S2, Wind speed compensation correction: The target occlusion height of the corresponding curtain is dynamically compensated and corrected based on wind speed and direction signals.

[0045] The preset wind speed threshold is 5 m / s. Wind speed and direction signals are collected in real time. When the wind speed exceeds 5 m / s and the wind direction is directly facing the ventilation opening (2), the target shielding height corresponding to the current temperature is dynamically adjusted upward according to the wind speed. The specific compensation method is as follows: for every 2 m / s increase in wind speed, the target shielding height is increased by 5%, and the maximum increase is no more than 20%. For example, when the ambient temperature is -10℃, the original target shielding height is 30% of the height of the upper ventilation opening. If the wind speed is measured to be 7 m / s and the wind direction is directly facing the ventilation opening, the target shielding height is increased to 35%; if the wind speed is 9 m / s, it is increased to 40%, and so on, in order to offset the risk of icing caused by the aggravation of the wind cooling effect.

[0046] S3. Synchronous correction and alarm: During the raising and lowering of the segmented windbreak curtain assembly, the height deviation of the left and right sides of the corresponding curtain is monitored in real time. When the deviation exceeds the preset threshold, it is judged that the curtain is misaligned, and deceleration, correction, stopping operation or alarm operation is performed according to the degree of deviation.

[0047] Specifically, this includes: setting metal sensor plates at equal intervals on the left and right edges of the curtain (the hole spacing is 100mm in this embodiment), installing magnetic proximity switches on the fixed guide rails on the left and right sides of the curtain respectively, generating a pulse when each metal sensor plate passes the magnetic proximity switch, and accumulating the count with a pulse counter.

[0048] When the curtain rises or falls, the position and deviation are determined by counting pulses of a magnetic proximity switch. S31. Curtain position calculation: Left side curtain height HL = counter L × hole spacing (hole spacing = 100mm); Right side curtain height HR = counter R × hole spacing (hole spacing = 100mm); ΔH = |HL - HR|; ΔH is the height deviation between the left and right sides of the curtain, in mm; Among them, counter L is the cumulative number of pulses detected by the left magnetic induction proximity switch, and counter R is the cumulative number of pulses detected by the right magnetic induction proximity switch.

[0049] S32. Correction Judgment: Set the first threshold H1 = 20mm and the second threshold H2 = 50mm.

[0050] When ΔH≤20mm, the curtain height deviation is considered normal and the roller shutter machine is operating normally. When 20mm < ΔH ≤ 50mm, it is determined that the curtain is slightly misaligned. At this time, the corresponding automatic roller shutter machine operating speed is reduced (for example, from the rated speed to 50% of the rated speed), or the corresponding automatic roller shutter machine is controlled to perform a preset small-amplitude reciprocating lifting and lowering motion (for example, lifting and lowering by 10mm twice) to try to automatically correct the deviation. When ΔH>50mm, it is determined that the curtain is seriously misaligned, and the corresponding automatic rolling shutter machine is immediately stopped and an audible and visual alarm is issued.

[0051] S4. Windproof fixing; (a) Guiding function during the lifting and lowering process; During the raising and lowering of the curtain, the two metal rods of each set of wind deflectors (i.e., the outer wind deflector metal rod (10a) and the inner wind deflector metal rod (10b)) constrain the movement direction of the curtain from both sides to prevent the curtain from shifting laterally or twisting, and to ensure that the curtain rises and falls smoothly along the designed trajectory.

[0052] Specifically, the wind deflector array is installed at 1.5-meter intervals along the horizontal direction of the ventilation opening, for a total of 6 sets. Each set of wind deflectors consists of two metal rods (i.e., the outer wind deflector metal rod (10a) and the inner wind deflector metal rod (10b)) made of Φ32mm hot-dip galvanized round steel, with a center-to-center distance of 180mm between the outer and inner wind deflector metal rods (10a and 10b). The curtain fabric edge is reinforced with a wear-resistant slider (made of polytetrafluoroethylene) embedded within the edging, and the gap between the slider and the metal rod is 2-3mm.

[0053] When the automatic roller blind machine drives the curtain to rise and fall, the wear-resistant sliders on the edge of the curtain slide along the channel between the two sets of metal rods. Because the center distance between the two metal rods (180mm) is greater than the maximum diameter of the curtain when it is rolled up (approximately 120mm), the curtain will not get stuck with the metal rods during the raising and lowering process. At the same time, the two metal rods limit the edge of the curtain from both sides, preventing the curtain from swaying laterally or twisting due to wind or mechanical vibration during the raising and lowering process.

[0054] Actual testing revealed that without a wind deflector, the lateral offset during the curtain's lifting and lowering process can reach 50-80mm, leading to increased friction between the curtain edge and the guide rail, and even jamming. By adopting a wind deflector structure, the lateral offset is reduced, the lifting and lowering operation is smoother, frictional resistance is reduced, and the service life and operational reliability of the curtain are significantly improved.

[0055] (ii) Wind-resistant supports in a static state; When the curtain is stationary, when wind acts on it, the wind pressure is transmitted through the curtain to multiple sets of vertical windbreaks, and then dispersed by the windbreaks to the tower foundation. Actual measurements show that under wind speeds of up to level 8 (approximately 20 m / s), using the windbreak array structure of this embodiment, the maximum sway amplitude of the curtain is reduced from approximately 300 mm without windbreaks to less than 50 mm, a reduction of over 80%. This keeps the curtain stable in the wind, preventing large swaying or flapping, effectively extending the curtain's service life and ensuring a good seal.

[0056] Example 2:

[0057] In this embodiment, the control method and system for winter antifreeze of a cooling tower are the same as in Embodiment 1, except that a steel cable hoisting structure for a windbreak curtain system is added. This structure is suitable for top-opening roller shutter machines, used to achieve smooth lifting and lowering of the curtain from bottom to top, and is especially suitable for lifting large-span or heavy-duty curtains.

[0058] The steel cable drive structure of the upper windshield curtain system is described below: See Figure 2 and Figure 3 The upper windshield curtain system (4) includes an upper windshield curtain power roller (43), an upper windshield curtain end shaft (42), a main steel cable (50), a main load-bearing wheel (51), a load-bearing reversing wheel (52), and a hanging steel cable (53).

[0059] (1) Upper windshield curtain power roller (43) and upper windshield curtain end shaft (42): The upper windshield power roller (43) is the active rotating component, installed 15-30cm below the metal crossbeam (9), and driven to rotate by a corresponding motor. The upper windshield end shaft (42) is the driven component, set parallel to the movable end of the curtain (i.e., the upper edge of the curtain). One end of the curtain is fixed and wound around the upper windshield power roller (43), and the other end of the curtain is fixed to the upper windshield end shaft (42). When the upper windshield power roller (43) rotates in the forward direction, it rolls up the curtain, causing the curtain to rise from top to bottom; when the upper windshield power roller (43) rotates in the reverse direction, it releases the curtain, and the curtain unfolds from bottom to top by the transmission of the steel cable.

[0060] (2) Main steel cable (50) and main load-bearing wheel (51): Two main steel cables (50) are provided, arranged on the left and right sides of the curtain respectively. One end of each main steel cable (50) is fixed to the end of the upper windshield end shaft (42), and the other end extends upward and passes around the main load-bearing roller (51). The main load-bearing roller (51) is installed on the fixed bracket at the top of the vent (2) and is used to change the transmission direction of the main steel cable (50). After passing around the main load-bearing roller (51), the main steel cable (50) extends downward and is finally fixed to the end of the upper windshield power roller (43) or the drum linked to the power roller. There are several main load-bearing rollers (51).

[0061] (3) Load-bearing reversing wheel (52) and suspension cable (53): There are several load-bearing reversing wheels (52) used to further distribute the lifting force. One end of the hoisting steel cable (53) is fixed to the tower structure, extends upward and passes around the load-bearing reversing wheel (52), then extends upward and passes around the main load-bearing wheel (51) to form a movable pulley structure.

[0062] (4) Transmission path and working principle: When the upper windshield power roller (43) rotates in the reverse direction (unfolding direction), it drives the main steel cable (50) to rotate, and then transmits force to multiple sets of hanging steel cables (53) through the load-bearing reversing wheel (52), driving the upper windshield end shaft (42) to lift upward and unfold the curtain of the upper windshield system (4). This structure can make the curtain evenly stressed and run smoothly during the unfolding process, avoiding curtain skewing or jamming caused by uneven gravity distribution.

[0063] When the upper windshield power roller (43) rotates in the forward direction (retracting direction), the upper windshield power roller (43) winds up the curtain of the upper windshield system (4), and at the same time pulls the main steel cable (50) to move from bottom to top. After the main load-bearing roller (51) reverses direction, the upper windshield end shaft (42) is released, causing it to move downward, so that the curtain of the upper windshield system (4) is smoothly retracted from top to bottom. The movable pulley structure formed by the load-bearing reversing roller (52) and the hanging steel cable (53) can effectively reduce the driving torque requirement of the power roller and reduce the motor load.

[0064] The pulley system, consisting of the main steel cable, main load-bearing roller, load-bearing reversing roller, and suspension steel cable, enables the smooth raising and lowering of the upper windshield curtain, making it particularly suitable for anti-freezing systems of large-span or heavy curtains. This structure reduces the power requirement of the drive motor, lowers equipment costs, and simultaneously improves the synchronization and operational reliability of the curtain's raising and lowering.

[0065] A steel cable pulley system (main steel cable, main load-bearing wheel, load-bearing reversing wheel, and hanging steel cable) was designed in the upper windproof curtain system, and a climbing rod and climbing device guide structure was designed in the lower windproof curtain system: (1) The pulley system forms a deceleration and force-increasing effect, which can effectively reduce the power demand of the drive motor and reduce equipment cost and energy consumption; (2) The climbing rod and climbing device structure ensures that the shaft at the end of the lower windproof curtain rises and falls smoothly along a fixed trajectory, prevents the lower edge of the curtain from shifting laterally and tilting, and ensures the levelness and sealing effect of the curtain after it is unfolded; (3) The above structure is especially suitable for antifreeze systems with excessive height (such as ventilation openings exceeding 5 meters) or heavy-duty curtains, which expands the scope of application of the present invention.

[0066] Example 3:

[0067] In this embodiment, the control method and system for winter antifreeze of a cooling tower are the same as in Embodiment 1, except that a climbing guide structure for the lower windbreak curtain system is added based on Embodiment 1 and / or Embodiment 2. This structure is suitable for bottom-opening roller shutter machines, used to achieve smooth unfolding of the curtain from top to bottom and smooth retraction from bottom to top, and is especially suitable for curtain lifting control that requires precise guidance.

[0068] The climbing guide structure of the lower windshield curtain system is as follows: See Figure 2 and Figure 3 The lower windshield curtain system (3) includes a bottom-opening automatic roller shutter machine (31), a lower windshield curtain end shaft (32), a lower windshield curtain power roller (33), a curtain (12), a climber (21) and a climbing rod (22). (1) Lower windshield curtain power roller (33) and lower windshield curtain end shaft (32): The lower windshield curtain power roller (33) is the active rotating component. The end shaft (32) is installed 15-30cm above the metal crossbeam (9) (lower windshield curtain system: the end shaft is the fixed end, and the power shaft will move up and down along the climbing rod, so the end shaft is fixed at the top), and is driven to rotate by the corresponding motor. The lower windshield curtain end shaft (32) is the driven component, which is set parallel to the fixed end of the curtain (i.e., the upper edge of the curtain of the lower windshield curtain system (3)). One end of the curtain (12) of the lower windshield curtain system (3) is fixed and wound around the lower windshield curtain power roller (33), and the other end of the curtain (12) is fixed to the lower windshield curtain end shaft (32). When the lower windshield curtain power roller (33) rotates in the forward direction, it releases the curtain (12), and the curtain (12) unfolds from top to bottom by its own weight; when the lower windshield curtain power roller (33) rotates in the reverse direction, it rolls up the curtain (12), so that the curtain (12) is pulled up from bottom to top.

[0069] (2) Climbing rod (22) and climbing device (21): The climbing rod (22) is a vertically parallel metal rod or guide rail installed on the right side of the ventilation opening (2) and fixed to the tower structure. The climbing rod (22) is made of hot-dip galvanized round steel or stainless steel, and its height runs through the entire ventilation opening, extending from below the metal crossbeam (9) to the bottom of the ventilation opening.

[0070] The climber (21) is a set of mechanical components that can slide up and down along the climbing rod (22) and is installed at the end of the lower windshield curtain power roller (33). Each climber (21) has a guide slider or roller inside, which forms a sliding or rolling engagement with the climbing rod (22). The climber (21) drives the lower windshield curtain power roller (33) to move vertically along the climbing rod (22), thereby driving the curtain to unfold and retract.

[0071] (3) Transmission path; When the lower windshield power roller (33) rotates in the reverse direction (unfolding direction), the lower windshield power roller (33) releases the curtain (12) and slides smoothly downward along the climbing rod (22). The curtain (12) unfolds downward with the power roller, and the lower windshield end shaft (32) realizes the unfolding action of the curtain (12) from top to bottom. The cooperation between the climbing rod (22) and the climber (21) can effectively limit the lateral swing and tilt of the lower windshield power roller (33), ensuring that the lower edge of the curtain unfolds horizontally and flatly.

[0072] When the windshield curtain's power roller (33) rotates in the forward direction (retraction direction), the climber (21) slides upward along the climber rod (22), the power roller winds up the curtain (12), and the end shaft (32) of the windshield curtain is fixed, tautning the curtain (12). This guides the curtain to retract smoothly, preventing the curtain from folding or shifting during the retraction process.

[0073] Example 4:

[0074] In this embodiment, a control method and system for winter antifreeze of a cooling tower is the same as in Embodiment 1, but with the addition of a detailed structure and working process of a curtain attitude sensing array based on Embodiment 1 and / or Embodiment 2 and / or Embodiment 3.

[0075] The curtain attitude sensing array, as detailed below: I. Layout and installation location of magnetic induction proximity switches; See Figure 1A segmented windbreak curtain assembly is installed on the outside of the ventilation opening (2) of the cooling tower (1), including an upper windbreak curtain system (4) and a lower windbreak curtain system (3). In order to monitor the lifting height of the two curtains and the synchronization of the left and right sides in real time, a total of four magnetic induction proximity switches are set up, namely: the left magnetic induction proximity switch (5a) of the upper windbreak curtain, the right magnetic induction proximity switch (5b) of the upper windbreak curtain, the left magnetic induction proximity switch (5c) of the lower windbreak curtain, and the right magnetic induction proximity switch (5d) of the lower windbreak curtain. Its specific layout is as follows: (1) Magnetic induction proximity switch (5a) on the left side of the upper windshield: Installed on the fixed guide rail on the left side of the upper windshield curtain system (4), located at the bottom starting end of the guide rail (i.e., the position corresponding to the lower edge of the curtain when the upper windshield curtain is fully retracted). This switch is used to detect the metal sensor (11) on the left edge of the upper windshield curtain. When the left curtain is raised or lowered, the metal sensor (11) passes through the switch in sequence, generating a pulse signal, which is used to calculate the height of the left curtain.

[0076] (2) Magnetic proximity switch (5b) on the right side of the upper windshield: Installed on the fixed guide rail on the right side of the upper windshield curtain system (4), located at the bottom starting end of the guide rail (at the same horizontal height as 5a), and symmetrically arranged with the left switch (5a). This switch is used to detect the metal sensor (11) on the right edge of the upper windshield curtain, generating a pulse signal to calculate the height of the right side curtain.

[0077] (3) Magnetic induction proximity switch (5c) on the left side of the lower windshield curtain: Installed on the fixed guide rail on the left side of the lower windshield curtain system (3), located at the top starting end of the guide rail (i.e., the position corresponding to the upper edge of the curtain when the lower windshield curtain is fully retracted, near the metal crossbeam (9)). This switch is used to detect the metal sensor (11) on the left edge of the lower windshield curtain. When the lower windshield curtain is raised or lowered, a pulse signal is generated to calculate the height or unfolded length of the left side curtain of the lower windshield curtain.

[0078] (4) Magnetic induction proximity switch (5d) on the right side of the lower windshield curtain: Installed on the fixed guide rail on the right side of the lower windshield curtain system (3), located at the top starting end of the guide rail (at the same horizontal height as 5c), and symmetrically arranged with the left switch (5c). This switch is used to detect the metal sensor (11) on the right edge of the lower windshield curtain, generating a pulse signal to calculate the height or unfolded length of the right side curtain of the lower windshield curtain.

[0079] Layout features: Four magnetic proximity switches correspond to the left and right sides of the upper and lower windshields, respectively, and monitor independently without interfering with each other; The switches (5a, 5b) for the upper windshield are installed at the bottom of the guide rail because the upper windshield unfolds from bottom to top, with the starting end (when fully retracted) located at the bottom. The switches (5c, 5d) for the lower windshield curtain are mounted on the top of the guide rail because the lower windshield curtain unfolds from top to bottom, with the starting end (when fully retracted) located at the top (near the metal crossbeam). Each switch is installed at the beginning of the corresponding curtain lifting stroke, ensuring accurate counting from the moment the curtain is fully retracted.

[0080] II. Working process / working principle of the curtain attitude sensing array; (1) Setting of metal sensor: Metal sensor sheets (11) are fixed at equal intervals along the length of the upper and lower windshield curtains on both sides. In this embodiment, the spacing (hole distance) between adjacent metal sensor sheets is 100mm. The metal sensor sheets are made of ferromagnetic material (such as galvanized iron sheet), with a size of 10mm×20mm and a thickness of 1mm, and are firmly embedded in the reinforcing edging of the curtain edge.

[0081] (2) Generation of pulse signals: When the curtain is raised and lowered by the roller shutter machine, the metal sensor (11) moves along with the curtain. When the metal sensor (11) passes the corresponding magnetic proximity switch (5a / 5b / 5c / 5d), the proximity switch detects the metal and outputs a pulse signal instantaneously (e.g., transitioning from low level to high level and then back to normal). Each time the metal sensor passes by, one pulse is generated. The pulse signal is transmitted in real time to the counter input of the control unit (PLC).

[0082] (3) Pulse counting and height calculation: The control unit internally assigns an independent pulse counter to each magnetic proximity switch, namely: counter L up, counter R up, counter L down, and counter R down.

[0083] Upper windshield curtain left side height HL 上 =Counter L 上 ×100mm; Upper windshield right side height HR 上 =Counter R 上 ×100mm; Lower windshield curtain left side height LL 下 =Counter L 下 ×100mm; Lower windshield curtain right side height LR 下 =Counter R 下 ×100mm; For the lower windshield curtain, since the curtain unfolds from top to bottom, the unfolded length is the blocking height, and the remaining retracted length of the curtain = total curtain length - unfolded length.

[0084] (4) Synchronization deviation monitoring: The control unit compares the counting differences between the left and right sides of the same curtain in real time to calculate the height deviation. Upper windshield curtain deviation: ΔH 上 =|HL 上 -HR 上 |; Lower windshield curtain deviation: ΔH 下 =|LL 下 -LR 下 |; When the deviation exceeds the preset threshold (H1=20mm, H2=50mm), the control unit performs the corresponding operation (deceleration, reciprocating correction, and stop alarm) according to the S32 correction strategy in Example 1.

[0085] (5) Reset and clear: When any curtain is fully retracted, the two counters corresponding to that curtain (e.g., counter L) 上 and counter R 上 The count is automatically reset so that it can start counting again for the next lifting and lowering process. The criteria for determining the fully retracted state are: the roller shutter moves to the end of the rated stroke in the retracting direction, or receives a trigger signal from the limit switch.

[0086] (6) Actual operation example: Taking the above windbreak curtain as an example: In the initial state, the curtain is fully retracted, and the counter L... 上 =0, counter R 上 =0. When the ambient temperature drops to -10℃, the control unit commands the upper windshield curtain to open upwards. During the curtain's ascent, the left metal sensor generates a pulse at 5a, which is incremented on counter L_; the right metal sensor generates a pulse at 5b, which is incremented on counter R_. Assume the left counter L... 上 =15, right-side counter R 上 =14, then the left side height =1500mm, the right side height =1400mm, the deviation ΔH =100mm>50mm, triggering a serious deviation alarm, the roller shutter machine stops immediately, the audible and visual alarm is activated, prompting the operator to check the transmission mechanism.

[0087] By independently installing magnetic induction proximity switches on the left and right sides of the upper and lower wind deflectors, independent pulse counting is achieved for four monitoring points across the two curtains, enabling precise calculation of the real-time height and synchronization deviation on both sides of each curtain. This layout scheme is simple in structure, low in cost, and has strong anti-interference capabilities. It is suitable for the low-temperature and humid operating environment of cooling towers, providing a reliable sensing basis for the system's automatic correction and fault alarm.

[0088] This invention features a cooling tower with a distinct height distribution of air intake, with significantly higher airflow at the bottom than at the top, resulting in a pronounced cold air sinking effect. The invention employs a segmented, independently driven windbreak curtain design. The control logic is as follows: the lower windbreak curtain unfolds first, prioritizing the shielding of the bottom area most prone to icing; the upper windbreak curtain unfolds segment by segment from bottom to top, blocking cold air from the bottom up. This control strategy aligns with the physical characteristic of cold air sinking, achieving optimal antifreeze effect with minimal shielding area. Compared to existing single-curtain overall control schemes, this invention reduces ineffective shielding area by approximately 30%-50%, correspondingly reducing fan energy consumption and resulting in significant energy savings. The upper and lower rollers are centrally installed near the metal beam in the middle of the ventilation opening, and the curtain is stored in the middle area of ​​the ventilation opening when retracted. The following multiple advantages: (1) It is far away from water splashing areas, avoiding long-term contact between the retracted curtain and the damp environment, effectively preventing the curtain from corroding and becoming mildewed, and extending its service life; (2) All mechanical and electrical components (roller shutter machine, motor, sensor, control unit, etc.) are concentrated in an easily accessible central area, which facilitates daily inspection, maintenance and replacement, and reduces installation difficulty and operation and maintenance costs; (3) It avoids setting large equipment at the top or bottom of the ventilation opening, optimizes space utilization, does not affect the uniform distribution of airflow, and does not occupy the maintenance passage; Through the segmented curtain design with independent upper and lower drives, combined with multi-parameter closed-loop control of ambient temperature and wind speed and direction, the step-by-step and fine adjustment of the ventilation area of ​​the ventilation opening is realized: (1) Multiple temperature thresholds (T1 (1) T2, T3), to achieve graded control, and adopt differentiated shielding strategies in different temperature ranges; (2) Introduce a wind speed compensation correction mechanism. When the wind speed exceeds the preset threshold and the wind direction is directly facing the ventilation opening, the target shielding height is dynamically adjusted according to the wind speed to effectively offset the additional icing risk caused by the wind cooling effect; (3) The control unit can flexibly adjust the control parameters according to the actual operating data. It is suitable for different regional climate conditions and cooling tower models, and has good adaptability and scalability; A wind deflector array structure was designed to transform the traditional planar wind deflector curtain into a multi-point supported guide structure: (1) Each wind deflector is composed of two parallel vertical metal rods. The curtain passes through between them to form a sliding guide rail structure, which provides precise guidance when the curtain rises and falls. (1) Provides wind-resistant support when stationary; (2) When strong winds act on the curtain, the wind pressure is transmitted through the curtain to multiple sets of windbreak bars, and then dispersed by the windbreak bars to the tower foundation to avoid stress concentration; (3) According to actual measurements, using the windbreak bar array structure of the present invention, under high wind speed conditions, the curtain swing amplitude is reduced from about 300mm without windbreak bars to less than 50mm, the swing amplitude is reduced by more than 80%, which enhances the stability and sealing of the system under strong wind conditions and effectively extends the service life of the curtain; The curtain posture online monitoring and graded correction alarm mechanism is designed: (1) Metal induction plates are set at equal intervals on the left and right edges of the curtain, and pulse counting is realized in conjunction with magnetic induction proximity switches to more accurately calculate the real-time height and synchronous deviation of the left and right sides of the curtain;(2) Two levels of deviation thresholds are set (H1=20mm, H2=50mm): When there is slight deviation, the machine automatically decelerates or performs small reciprocating motion to try to self-correct; when there is severe deviation, the machine stops immediately and an audible and visual alarm is triggered to avoid equipment damage; (3) This mechanism can provide timely warning and locate mechanical transmission faults (such as roller bending, curtain jamming, motor asynchrony, etc.), avoiding overall functional failure or equipment damage caused by single-point faults, and significantly improving the operational reliability of the system; using mature and reliable roller shutter machines, proximity switches, metal rods and other components, and an optimized combination of control logic and mechanical structure, without the need for expensive or scarce materials, this invention has obvious advantages in terms of initial investment and long-term operating costs, and is easy to promote and apply in new cooling tower projects and renovation projects of existing cooling towers.

Claims

1. A method for controlling the freezing of cooling towers in winter, characterized in that, include: S1. According to the ambient temperature, the temperature is controlled in stages. Multiple temperature thresholds are set to control the unfolding height of the curtain of the upper windproof curtain system (4) and the curtain of the lower windproof curtain system (3) respectively, so as to adjust the ventilation area of ​​the ventilation opening (2) in stages. S2. Dynamically compensate and correct the target occlusion height of the corresponding curtain based on wind speed and direction signals. S3. During the lifting and lowering of the segmented windbreak curtain assembly, the height deviation of the left and right sides of the corresponding curtain is monitored in real time. When the deviation exceeds the preset threshold, it is judged that the curtain is misaligned, and deceleration, correction, stop operation or alarm operation is performed according to the degree of deviation. S4. Multiple sets of vertical windbreak bars arranged on both sides of the curtain provide guidance when the curtain is raised and lowered, and provide wind-resistant support when stationary, to prevent the curtain from swinging or flapping in the wind.

2. A control method for winter anti-freezing of a cooling tower according to claim 1, wherein In S1, the graded regulation specifically includes: When the ambient temperature T > temperature threshold T1, the curtains of the upper windshield curtain system (4) and the lower windshield curtain system (3) are completely retracted. When the temperature threshold T2 < ambient temperature T ≤ temperature threshold T1, the curtain of the lower windshield curtain system (3) unfolds from top to bottom to block the lower half of the ventilation opening (2), while the curtain of the upper windshield curtain system (4) remains folded up. When the temperature threshold T3 < ambient temperature T ≤ temperature threshold T2, the curtain of the upper windshield curtain system (4) unfolds from bottom to top, and the upper part of the shielding height is increased linearly or in stages according to the degree of temperature drop. When the ambient temperature T ≤ temperature threshold T3, the curtain of the upper windshield curtain system (4) is unfolded to the maximum design shielding height, leaving only the minimum ventilation gap; in: Multiple temperature thresholds include temperature threshold T1, temperature threshold T2, and temperature threshold T3, and temperature threshold T1 > temperature threshold T2 > temperature threshold T3.

3. The control method for winter anti-freezing of a cooling tower according to claim 1, wherein In S2, the dynamic compensation and correction of the target occlusion height of the corresponding curtain based on wind speed and direction signals specifically includes: Real-time wind speed and direction signals are collected. When the wind speed exceeds the preset wind speed threshold and the wind direction is directly facing the ventilation opening (2), the target shading height corresponding to the current temperature is dynamically adjusted upward according to the wind speed. The adjustment range is positively correlated with the wind speed value to offset the risk of icing caused by the aggravated wind cooling effect.

4. The control method for winter anti-freezing of a cooling tower according to claim 1, wherein In S3, the specific actions of deceleration, correction, stopping operation, or alarm based on the degree of deviation include: Metal sensor plates are evenly spaced on the left and right edges of the curtain. Magnetic proximity switches are installed on the fixed guide rails on the left and right sides of the curtain. Each metal sensor plate generates a pulse when it passes the magnetic proximity switch. The pulse counter is accumulated. When the curtain is raised or lowered, the position and deviation are determined by counting pulses of a magnetic proximity switch, specifically including: S31. Curtain position calculation: (1) The height of the left side curtain is expressed as: Left side curtain height HL = counter L × hole spacing; in: The aperture spacing is the distance between adjacent metal induction plates, in mm; The counter L represents the cumulative number of pulses detected by the left-side magnetic proximity switch; The height of the left-side curtain, HL, is in mm; (2) The height of the right-side curtain is expressed as: Right side curtain height HR = counter R × hole spacing; in: The counter R represents the cumulative number of pulses detected by the magnetic proximity switch on the right, in units of pulses. (3) Deviation, expressed as: ΔH = |HL - HR|; ΔH is the height deviation between the left and right sides of the curtain, in mm; S32. Correction Judgment: When ΔH ≤ the first threshold H1, the curtain height deviation is determined to be normal; When the first threshold H1 < ΔH ≤ the second threshold H2, it is determined that the curtain is slightly misaligned. At this time, the corresponding automatic roller shutter machine running speed is reduced, or the corresponding automatic roller shutter machine is controlled to perform a preset small-amplitude reciprocating lifting and lowering motion to try to automatically correct the deviation. When ΔH > the second threshold H2, it is determined that the curtain is seriously misaligned, and the corresponding automatic rolling shutter machine is immediately stopped and an audible and visual alarm is issued.

5. The method of claim 1, wherein the control method is characterized by: In S4, the provision of multiple sets of vertical windbreaks arranged on both sides of the curtain to provide guidance during curtain raising and lowering and wind-resistant support when stationary specifically includes: During the raising and lowering of the curtain, each set of windbreak rods constrains the direction of movement of the curtain to prevent the curtain from shifting laterally or twisting. When the curtain is stationary, when the wind acts on the curtain, the wind pressure is transmitted through the curtain to multiple sets of vertical windbreak bars, and then distributed by the windbreak bars to the tower foundation, so that the curtain remains stable in the wind and avoids large swings or slaps.

6. A control system for the winter de-icing of cooling towers according to any one of the preceding claims, characterized in that, Includes a segmented windbreak curtain assembly, which is installed on the outside of the ventilation opening (2) of the cooling tower (1); a metal crossbeam (9) is fixedly installed in the middle of the ventilation opening (2); The segmented windshield assembly includes a lower windshield system (3) and an upper windshield system (4), and a windshield bar array. The lower windshield curtain system (3) is installed above the metal beam (9). The curtain of the lower windshield curtain system (3) unfolds from top to bottom to adjust the ventilation area of ​​the lower half of the vent (2). The upper windshield curtain system (4) is installed below the metal crossbeam (9). The curtain of the upper windshield curtain system (4) unfolds from bottom to top to adjust the ventilation area of ​​the upper part of the vent. The windbreak bar array includes several sets of windbreak bars spaced at intervals along the horizontal direction of the ventilation opening (2). Each set of windbreak bars is parallel to each other. Each set of windbreak bars includes two parallel outer windbreak metal bars (10a) and inner windbreak metal bars (10b). The outer windbreak metal bars (10a) and inner windbreak metal bars (10b) are arranged alternately. The curtain passes through the gap between each set of outer windbreak metal bars (10a) and inner windbreak metal bars (10b) to form a wave shape. The upper and lower ends of each set of windbreak bars are fixed to the pre-embedded parts of the cooling tower (1) foundation.

7. A control system for winter freeze protection of a cooling tower as defined in claim 6 wherein, The vertical distance between the roller of the upper windproof curtain system (4) and the roller of the lower windproof curtain system (3) is 30~50cm, and the curtain of the upper windproof curtain system (4) and the curtain of the lower windproof curtain system (3) have an overlapping area of ​​15~25cm in their range of motion.

8. A control system for winter antifreeze of a cooling tower according to claim 6, characterized in that: The center-to-center spacing of each set of windbreak bars is 150~200mm, which is greater than the maximum diameter of the roller shutter when it is rolled up; Each set of windbreak bars is a metal round bar with a diameter of 25~40mm or a metal square tube with an equivalent cross section, and its height extends through the entire ventilation opening (2). In the windbreak bar array, the center distance between adjacent groups of windbreak bars is 1 to 2 meters.

9. A control system for winter freeze protection of a cooling tower as defined in claim 6 wherein, It also includes a multi-parameter sensing module and a control unit, including at least an ambient temperature sensor for monitoring ambient temperature, a wind speed and direction sensor for monitoring wind speed and direction, and a curtain attitude sensing array for monitoring the curtain's unfolding attitude. The curtain attitude sensing array includes multiple position or displacement sensors spaced along the active edge of the curtain, used to provide real-time feedback of height or displacement information at different points on the edge of the curtain. The control unit is connected to the multi-parameter sensing module, the magnetic induction proximity switch, the bottom-opening automatic roller shutter, and the top-opening automatic roller shutter, respectively.

10. A control system for winter antifreeze of a cooling tower according to claim 6, characterized in that: The metal beam (9) is connected to a reinforcing rib at the bottom or side to enhance the structural rigidity of the metal beam. The lower windbreak curtain system (3) is driven by a bottom-opening automatic roller shutter machine; The aforementioned upper windbreak curtain system (4) is driven by an upper-opening automatic roller shutter machine.

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