Ventilation cooling tower anti-freezing and heat exchange optimization energy-saving method

Abstract

The invention relates to the technical field of cooling towers, and discloses a ventilation cooling tower anti-freezing and heat exchange optimization energy-saving method, which comprises the following steps: S1, monitoring multi-region parameters of a cooling tower in real time, including inlet water temperature difference, outlet water temperature difference, air wet bulb temperature and tower wall icing thickness distribution, S2, dynamically dividing an anti-freezing priority region of the cooling tower according to the multi-region parameters, wherein the high-frequency vibration area and the low-temperature air outlet area are automatically marked as a first-level anti-freezing area, S3, an anti-freezing early warning model based on historical icing data is established, and when it is detected that the icing thickness acceleration of any sub-area in the first-level anti-freezing area exceeds a preset threshold value, a gradient response mechanism is triggered. According to the method, the freezing phenomenon is accurately inhibited by monitoring the multi-region parameters of the cooling tower in real time, dynamically dividing the anti-freezing priority regions and combining a gradient response mechanism, differential measures can be taken according to freezing risks of different regions, and the problems of high energy consumption and response lag in a traditional anti-freezing method are effectively avoided.

Description

Technical Field

[0001] This invention relates to the field of cooling tower technology, specifically to a method for preventing freezing and optimizing heat exchange in ventilation cooling towers to save energy. Background Technology

[0002] In thermal power plants, the operating efficiency of ventilation cooling towers directly affects the overall performance of the unit. However, in low-temperature environments, cooling towers are prone to icing, leading to damage to the tower wall structure, increased ventilation resistance, and decreased heat exchange efficiency. Traditional antifreeze methods (such as electric heat tracing or fixed hot water jetting) have problems such as high energy consumption, slow response, and uneven coverage. Furthermore, they lack dynamic prediction and graded control of the icing process. In addition, heat exchange optimization during non-antifreeze periods often adopts fixed operating modes, which are difficult to adapt to seasonal changes, resulting in energy waste. Summary of the Invention

[0003] The purpose of this invention is to provide a method for preventing freezing and optimizing heat exchange in ventilation cooling towers to save energy, so as to solve the problems mentioned in the background art.

[0004] To achieve the above objectives, the present invention provides the following technical solution: a method for antifreeze and heat exchange optimization and energy saving of a ventilation cooling tower, comprising the following steps: S1. Real-time monitoring of multiple parameters in the cooling tower, including inlet water temperature difference, outlet water temperature difference, air wet-bulb temperature, and distribution of ice thickness on the tower wall; S2. Based on the multi-region parameters, the cooling tower is dynamically divided into antifreeze priority zones, where the high-frequency vibration zone and the low-temperature air outlet zone are automatically marked as the first-level antifreeze zone. S3. Establish an anti-freezing early warning model based on historical icing data. When the icing thickness growth rate of any sub-region within the primary anti-freezing zone exceeds the preset threshold, a gradient response mechanism is triggered. S4. Implement graded antifreeze control: In the initial response stage, adjust the water spray density of this sub-area to 70%-85% of the baseline value; in the intermediate response stage, reduce the ventilation volume of adjacent areas by 10%-15%; in the advanced response stage, activate the rotating hot water curtain jet. S5. During non-freezing periods, switch the heat exchange optimization mode according to seasonal characteristics. In summer, use a combination of high water density and low circulation rate, and in winter, use a combination of variable tilt angle water distribution and delayed water drop. S6. Dynamically correct antifreeze control parameters through vortex detection feedback at the air outlet until the ice thickness drops back to the safe threshold, and establish an antifreeze energy consumption assessment system.

[0005] As a preferred technical solution of the present invention, the division of the antifreeze priority area in step S2 further includes setting the annular zone 0.5-1.2m away from the tower wall as the secondary antifreeze zone. This zone adopts intermittent hot water pulse antifreeze, and the pulse period is inversely proportional to the real-time wind speed.

[0006] As a preferred technical solution of the present invention, the intermittent hot water pulse antifreeze specifically includes: setting a temperature gradient detection point in the secondary antifreeze zone; when the temperature difference between the inside and outside of the tower wall is detected to be >8℃, the preheating stage of pulse antifreeze is started; after preheating for 30-60 seconds at 50% of the reference hot water flow rate, the pulse jet stage is entered; the jetting duration of the pulse jet stage is positively correlated with the reciprocal of the real-time wind speed, and the interval between single pulses is ≤120 seconds; after the pulse ends, the waste heat utilization cycle is started, and the residual hot water is introduced into the water distribution system of the adjacent non-icing zone.

[0007] As a preferred technical solution of the present invention, the establishment of the anti-freezing early warning model in step S3 specifically includes: collecting spatiotemporal distribution data of icing locations for at least three winter operating cycles, and constructing an icing thermodynamic characteristic spectrum, wherein the spectrum contains a nonlinear correspondence between icing thickness and water spray density at different wet-bulb temperatures.

[0008] As a preferred embodiment of the present invention, the construction of the icing thermodynamic characteristic spectrum specifically includes: S31. Data stratification and collection: Historical icing data are collected according to wet-bulb temperature range. Specifically, the wet-bulb temperature range is -20℃ to 0℃, and each 2℃ range is divided into a sub-range. Each sub-range contains at least 200 valid samples. The samples include the extreme distribution of icing thickness, the gradient of water spray density at the corresponding time, and the wind speed vector. S32. Feature Correlation Modeling: Nonlinear regression analysis is performed on the icing thickness and water spray density within each wet-bulb temperature sub-interval to generate three feature curves, namely the critical icing curve, the safe operation curve, and the transition warning curve. S33. Dynamic correction mechanism: In real-time operation, when the actual freezing rate deviates from the predicted value of the spectrum by more than 15%, the following corrections are triggered: if the ambient humidity is continuously >85%, the corresponding sub-interval of the current wet-bulb temperature will be automatically lowered by 1℃; if the water hardness changes by >10%, the corresponding compensation coefficient will be added to the water spray density threshold.

[0009] As a preferred technical solution of the present invention, the variable tilt angle water distribution in step S5 specifically includes: adjusting the elevation angle of the water distributor nozzle from 15 degrees to 25-30 degrees in winter mode to form a parabolic water droplet trajectory and extend the residence time of the water droplets in the air by 0.8-1.5 seconds.

[0010] As a preferred technical solution of the present invention, the eddy current detection feedback in step S6 specifically includes: identifying the intensity of the eddy current at the air outlet using a Doppler anemometer, and automatically increasing the jet pressure of the hot water curtain in the first-level antifreeze zone by 5-8% when the detected eddy current intensity exceeds the critical value.

[0011] As a preferred embodiment of the present invention, the establishment of the antifreeze energy consumption assessment system specifically includes: S61. Multi-dimensional energy consumption data calibration: Record energy consumption data according to the type of anti-freezing measures, including the cumulative flow and temperature rise energy consumption of hot water curtain spray, the change in power consumption of circulating water pump caused by water density adjustment, and the extra work done by the fan corresponding to the ventilation volume adjustment. Set a benchmark conversion factor for each type of energy consumption. Among them, the energy consumption of hot water curtain is based on the energy consumption of temperature rise in the 70-75℃ range. S62. Quantification of icing suppression effectiveness: After defining the reduction in icing thickness per unit time as the core effectiveness index, a mapping relationship library between antifreeze measures and effectiveness indexes is established. Specifically, this includes linear suppression effectiveness corresponding to individual hot water curtain spraying, stepped suppression effectiveness corresponding to the linkage adjustment of water spray density and ventilation volume, and azimuth-weighted effectiveness corresponding to the adjustment of rotary nozzle orientation. S63. Dynamic Energy Efficiency Ratio Assessment: Divide the total energy consumption of the current antifreeze measures by the real-time icing suppression efficiency to obtain the dynamic energy efficiency ratio. At the same time, set three energy efficiency thresholds: excellent, warning, and deterioration. When the energy efficiency ratio of the excellent level is ≤0.8, the current measures are maintained. When the energy efficiency ratio of the warning level is >0.8 and ≤1.2, parameter optimization is triggered. When the energy efficiency ratio of the deterioration level is >1.2, the standby mode is forcibly switched. S64. Historical data retrospective correction: Extract the execution records of anti-freezing measures every month, manually mark abnormal operating conditions, retrospectively update the mapping relationship database, and prioritize the elimination of measure combinations that trigger the degradation level three times consecutively.

[0012] As a preferred technical solution of the present invention, the rotating hot water curtain spray in step S4 automatically adjusts the rotation speed of the nozzle according to the spatial distribution difference of the ice thickness in the primary antifreeze zone. Specifically, the sub-region with ice thickness ≥ 5 mm corresponds to the high-speed rotation mode, i.e., 15-20 r / min; the sub-region with ice thickness 3-5 mm corresponds to the medium-speed rotation mode, i.e., 8-12 r / min; and the sub-region with ice thickness < 3 mm corresponds to the low-speed scanning mode, i.e., 3-5 r / min. The spray coverage area maintains a dynamic buffer zone of 0.2-0.5 m from the edge of the ice area.

[0013] As a preferred technical solution of the present invention, the delayed water droplet formation specifically involves: setting a low-speed turbulent air curtain 0.8-1.2m below the water distributor, with the air speed controlled at 0.3-0.6m / s; then adjusting the nozzle orifice diameter of the water distributor to distribute the water droplet diameter in the range of 2-4mm; monitoring the water droplet falling speed in real time; and automatically increasing the tilt angle of the turbulent air curtain by 5-10 degrees when the detected speed is higher than 70% of the reference value. Finally, obtaining the water droplet cooling curve using an infrared thermal imager, dynamically optimizing the air curtain's action time, and matching it with the water droplet's residence time.

[0014] As a preferred technical solution of the present invention, the specific content of triggering the gradient response mechanism in step S3 includes triggering conditions and dynamic termination. Specifically, when the real-time ice thickness growth rate of any sub-region within the first-level anti-freezing zone exceeds a preset threshold, the anti-freezing early warning model triggers the gradient response mechanism.

[0015] As a preferred embodiment of the present invention, the conditions for dynamic termination are: triggering a termination response when the ice thickness drops to <1mm and triggering a termination response when the energy efficiency ratio is rated as excellent.

[0016] Compared with the prior art, the beneficial effects of the present invention are: 1. By monitoring the parameters of multiple areas of the cooling tower in real time, dynamically dividing the antifreeze priority areas, and combining the gradient response mechanism, such as water spray density adjustment, ventilation volume linkage and rotating hot water curtain spray, the icing phenomenon can be accurately suppressed. This method can take differentiated measures according to the icing risk of different areas, effectively avoiding the problems of high energy consumption and slow response in traditional antifreeze methods, while significantly reducing the icing risk of the cooling tower.

[0017] 2. The anti-freezing early warning model built based on historical icing data can dynamically adjust the anti-freezing strategy by combining real-time environmental parameters such as wet-bulb temperature and wind speed. Through the establishment and correction mechanism of icing thermodynamic characteristic spectrum, the accuracy and adaptability of anti-freezing measures are improved, ensuring efficient operation under complex environmental conditions.

[0018] 3. During non-freezing periods, the heat exchange optimization mode is automatically switched according to seasonal characteristics. In summer, a combination of high water density and low circulation ratio is used, while in winter, variable tilt angle water distribution and delayed water drop technology are used, which significantly improves the heat exchange efficiency of the cooling tower. This flexible operation mode can adapt to environmental changes in different seasons and avoid energy waste.

[0019] 4. By establishing an antifreeze energy consumption assessment system, the correspondence between antifreeze measures and ice-inhibiting effectiveness is quantified, and the energy efficiency ratio is dynamically optimized. This method can evaluate the energy consumption performance of the combination of measures in real time, avoid excessive energy consumption, and switch to a more efficient standby mode when necessary to achieve energy-saving goals.

[0020] 5. By adopting technologies such as intermittent hot water pulse antifreeze, waste heat utilization circulation, and eddy current detection feedback, energy utilization efficiency is maximized. For example, hot water pulse antifreeze reduces hot water consumption through the combination of preheating and pulse jet, and delayed water droplet technology extends the residence time of water droplets through turbulent air curtain, thereby improving heat exchange efficiency. The application of these innovative technologies further enhances the operating efficiency and energy-saving potential of the cooling tower.

[0021] 6. By using historical data backtracking and anomaly detection modules, we continuously optimize the combination of antifreeze measures, eliminate inefficient strategies, and ensure the long-term stable operation of the system. At the same time, the design of dynamic buffer zone and rotating hot water curtain effectively avoids mechanical fatigue and ice expansion, and improves the durability of the equipment. Detailed Implementation

[0022] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0023] This invention provides a method for preventing freezing and optimizing heat exchange in ventilation cooling towers, comprising the following steps: S1. Real-time monitoring of multiple parameters in the cooling tower, including inlet water temperature difference, outlet water temperature difference, air wet-bulb temperature, and tower wall ice thickness distribution. This step specifically involves: arranging a high-precision fiber optic temperature sensor array inside the cooling tower, using distributed temperature measurement technology to ensure that the monitoring error of the inlet and outlet water temperature differences is ≤ ±0.2℃; detecting the tower wall ice thickness using a dual-mode method of millimeter-wave radar and infrared thermal imaging, with radar measuring the absolute ice thickness and infrared imaging identifying thermodynamic anomalies in the ice distribution; and fusing the two data to generate a three-dimensional ice thickness distribution map. The air wet-bulb temperature monitoring point uses an anti-freeze humidity sensor installed in the core area of ​​the air outlet vortex, with the sensor surface coated with an anti-icing coating to prevent ice from interfering with data acquisition. S2. The cooling tower is dynamically divided into antifreeze priority zones based on multi-region parameters. The high-frequency vibration zone and the low-temperature air outlet zone are automatically marked as the first-level antifreeze zone. The specific steps for dividing the priority zones are as follows: an array of acoustic wave sensors is installed on the inner side of the tower wall to capture the acoustic signals of microcracks generated in the early stage of icing (frequency range 20-40kHz). When the acoustic signal intensity of a certain sub-region exceeds 150% of the baseline value for 3 consecutive minutes, it is temporarily upgraded to the first-level antifreeze zone even if the ice thickness does not reach the threshold. The width of the annular zone of the second-level antifreeze zone (0.5-1.2m) is dynamically adjusted according to the tower structure. For hyperbolic cooling towers, it is automatically compressed to 0.5m at the tower throat to reduce hot water consumption, while it is expanded to 1.2m at the bottom expansion section to cover a larger antifreeze area. S3. Establish an anti-freezing early warning model based on historical icing data. When the icing thickness growth rate of any sub-region within the primary anti-freezing zone exceeds the preset threshold, a gradient response mechanism is triggered. S4. Implement graded antifreeze control: In the initial response stage, adjust the water spray density of the sub-area to 70%-85% of the baseline value. In the intermediate response stage, reduce the ventilation volume of adjacent areas by 10%-15%. In the advanced response stage, activate the rotating hot water curtain spray. The specific spraying steps of the rotating hot water curtain are as follows: The nozzle adopts a dual-channel design. 70-75℃ antifreeze hot water is sprayed in the inner channel, and compressed air is released in the outer channel to form an aerodynamic barrier, which increases the coverage radius of the hot water curtain by 30%. When the high-speed rotation mode (15-20r / min) lasts for more than 5 minutes, a 2-minute medium-speed transition period (10r / min) is automatically inserted to prevent mechanical bearings from fatigue due to sudden temperature changes. The 0.2-0.5m range of the dynamic buffer zone is dynamically adjusted according to the temperature gradient at the edge of the freezing zone. The boundary is scanned every 10 seconds to ensure that the hot water curtain always covers the potential freezing expansion area ahead of time. S5. During non-freezing periods, the heat exchange optimization mode is switched according to seasonal characteristics. In summer, a combination of high water density and low circulation ratio is used, while in winter, a combination of variable tilt angle water distribution and delayed water drop is used. The specific steps of delayed water drop are as follows: the generation of the low-speed turbulent air curtain adopts a biomimetic design. A honeycomb-shaped air duct is arranged below the water distributor. Each air duct unit independently controls the wind speed (0.3-0.6m / s). The air duct outlet is at a 15-degree oblique angle, forming an upward airflow similar to the wingtip vortex of an aircraft. The water droplet diameter is controlled by a smart nozzle. A piezoelectric ceramic actuator is built into the nozzle. Based on the water droplet speed feedback monitored by infrared, the aperture change is finely adjusted in real time by ±0.1mm to ensure that more than 90% of the water droplets fall in the 2-4mm target range. Infrared thermal imaging data is input into the neural network every 30 seconds to dynamically predict the matching relationship between the optimal air curtain action time and the water droplet trajectory. S6. Dynamically correct antifreeze control parameters through eddy current detection feedback at the air outlet until the ice thickness drops back to the safe threshold, and establish an antifreeze energy consumption assessment system. The specific steps of eddy current detection are as follows: the data of the Doppler anemometer is linked with the panoramic camera at the top of the tower: when the anemometer detects that the eddy current intensity exceeds the limit, it automatically retrieves the image of the steam form at the air outlet from the camera and generates an image recognition set. The eddy current type is determined by the image recognition set. When the thermal eddy current triggers the hot water curtain pressure to rise to 5-8%, the fan speed is adjusted first for the mechanical eddy current. At the same time, an ultrasonic atomizer is installed at the air outlet to spray tracer water mist with a diameter of 10-20μm into the core area of ​​the eddy current. The eddy current intensity calculation model of the anemometer is corrected by tracking the movement trajectory of the water mist.

[0024] Furthermore, the division of the antifreeze priority zone in step S2 also includes setting the annular zone 0.5-1.2m away from the tower wall as the secondary antifreeze zone. This zone uses intermittent hot water pulse antifreeze, and the pulse period is inversely proportional to the real-time wind speed.

[0025] Furthermore, the intermittent hot water pulse antifreeze specifically includes: setting up temperature gradient detection points in the secondary antifreeze zone; when the temperature difference between the inside and outside of the tower wall is detected to be >8℃, the preheating stage of pulse antifreeze is started; after preheating for 30-60 seconds at 50% of the reference hot water flow rate, the pulse jet stage is entered; the jetting duration of the pulse jet stage is positively correlated with the reciprocal of the real-time wind speed, and the interval between single pulses is ≤120 seconds; after the pulse ends, the waste heat utilization cycle is started, and the residual hot water is introduced into the water distribution system of the adjacent non-icing zone.

[0026] Furthermore, the establishment of the anti-freezing early warning model in step S3 specifically includes: collecting spatiotemporal distribution data of icing locations for at least three winter operating cycles, and constructing an icing thermodynamic characteristic map, wherein the map contains a nonlinear correspondence between icing thickness and water spray density at different wet-bulb temperatures.

[0027] Furthermore, the construction of the icing thermodynamic characteristic spectrum specifically includes: S31. Data stratification and collection: Historical icing data are collected separately according to wet-bulb temperature range. The wet-bulb temperature range is -20℃ to 0℃, and each 2℃ range is divided into a sub-range. Each sub-range contains at least 200 valid samples. The samples include the extreme distribution of icing thickness, the corresponding water spray density gradient, and the wind speed vector. S32. Feature Correlation Modeling: Nonlinear regression analysis is performed on the icing thickness and water spray density within each wet-bulb temperature sub-interval to generate three feature curves, namely the critical icing curve, the safe operation curve, and the transition warning curve. S33. Dynamic correction mechanism: In real-time operation, when the actual freezing rate deviates from the predicted value of the spectrum by more than 15%, the following corrections are triggered: if the ambient humidity is continuously >85%, the corresponding sub-interval of the current wet-bulb temperature will be automatically lowered by 1℃; if the water hardness changes by >10%, the corresponding compensation coefficient will be added to the water spray density threshold.

[0028] Furthermore, the variable tilt angle water distribution in step S5 specifically includes: adjusting the elevation angle of the water distributor nozzle from 15 degrees to 25-30 degrees in winter mode to form a parabolic water droplet trajectory and extend the residence time of the water droplets in the air by 0.8-1.5 seconds.

[0029] Furthermore, the eddy current detection feedback in step S6 specifically includes: identifying the intensity of the eddy current at the air outlet using a Doppler anemometer; and automatically increasing the jet pressure of the hot water curtain in the first-level antifreeze zone by 5-8% when the detected eddy current intensity exceeds the critical value.

[0030] Furthermore, the establishment of an antifreeze energy consumption assessment system specifically includes: S61. Multi-dimensional energy consumption data calibration: Record energy consumption data according to the type of anti-freezing measures, including the cumulative flow and temperature rise energy consumption of hot water curtain spray, the change in power consumption of circulating water pump caused by water density adjustment, and the extra work done by the fan corresponding to the ventilation volume adjustment. Set a benchmark conversion factor for each type of energy consumption. Among them, the energy consumption of hot water curtain is based on the energy consumption of temperature rise in the 70-75℃ range. S62. Quantification of icing suppression effectiveness: After defining the reduction in icing thickness per unit time as the core effectiveness index, a mapping relationship library between antifreeze measures and effectiveness indexes is established. Specifically, this includes linear suppression effectiveness corresponding to individual hot water curtain spraying, stepped suppression effectiveness corresponding to the linkage adjustment of water spray density and ventilation volume, and azimuth-weighted effectiveness corresponding to the adjustment of rotary nozzle orientation. S63. Dynamic Energy Efficiency Ratio Assessment: Divide the total energy consumption of the current antifreeze measures by the real-time icing suppression efficiency to obtain the dynamic energy efficiency ratio. At the same time, set three energy efficiency thresholds: excellent, warning, and deterioration. When the energy efficiency ratio of the excellent level is ≤0.8, the current measures are maintained. When the energy efficiency ratio of the warning level is >0.8 and ≤1.2, parameter optimization is triggered. When the energy efficiency ratio of the deterioration level is >1.2, the standby mode is forcibly switched. Digital twin technology is introduced into the dynamic evaluation of energy efficiency ratio to establish a real-time energy consumption simulation model of the cooling tower. When the actual energy efficiency ratio enters the warning level, the simulation model automatically generates three sets of optimization schemes, such as "maintain the current measures but shorten the hot water curtain pulse interval by 10%" or "reduce the ventilation volume by 5% while increasing the water spray density by 3%". Operators can select the optimal solution based on the ice suppression efficiency and energy consumption curve predicted by the model.

[0031] S64. Historical data retrospective correction: Extract the execution records of anti-freezing measures every month, manually mark abnormal operating conditions, retrospectively update the mapping relationship database, and prioritize the elimination of measure combinations that trigger the degradation level three times consecutively.

[0032] An automatic anomaly detection module is added to the historical data backtesting. This module identifies outliers in the energy consumption data and marks possible environmental interference factors, such as sudden heavy rain or grid voltage fluctuations.

[0033] Furthermore, in step S4, the rotating hot water curtain spray automatically adjusts the nozzle rotation speed according to the spatial distribution differences of ice thickness within the primary antifreeze zone. Specifically, sub-regions with ice thickness ≥ 5 mm correspond to a high-speed rotation mode (15-20 r / min), sub-regions with ice thickness 3-5 mm correspond to a medium-speed rotation mode (8-12 r / min), and sub-regions with ice thickness < 3 mm correspond to a low-speed scanning mode (3-5 r / min). A dynamic buffer zone of 0.2-0.5 m is maintained between the spray coverage area and the edge of the ice area.

[0034] Furthermore, the delayed water droplet placement involves: setting a low-speed turbulent air curtain 0.8-1.2m below the water distributor, with the air speed controlled at 0.3-0.6m / s; then adjusting the nozzle orifice diameter of the water distributor to distribute the water droplet diameter within the 2-4mm range; monitoring the water droplet falling speed in real time; and automatically increasing the tilt angle of the turbulent air curtain by 5-10 degrees when the detected speed exceeds 70% of the baseline value. Finally, using an infrared thermal imager, the water droplet cooling curve is obtained, and the matching relationship between the air curtain's action time and the water droplet residence time is dynamically optimized.

[0035] Furthermore, the specific content of triggering the gradient response mechanism in step S3 includes the triggering conditions and dynamic termination. Specifically, when the real-time ice thickness growth rate of any sub-region within the first-level anti-freezing zone exceeds the preset threshold, the anti-freezing early warning model triggers the gradient response mechanism.

[0036] Furthermore, the conditions for dynamic termination are: triggering the termination response when the ice thickness drops to <1mm and triggering the termination response when the energy efficiency ratio is rated as excellent.

[0037] Experimental Tables and Data Description To verify the practical effect of the proposed method for antifreeze and heat exchange optimization energy saving of ventilation cooling towers, the following experimental data are provided to demonstrate its antifreeze performance, heat exchange efficiency, and energy saving performance under different operating conditions. The experimental data will focus on the following core objectives: 1. Antifreeze performance verification: By comparing indicators such as ice thickness and antifreeze response time, the effectiveness of graded antifreeze control is demonstrated.

[0038] 2. Heat exchange optimization effect: Demonstrates the improvement of heat exchange efficiency by switching seasonal modes (such as variable tilt water distribution, delayed water drop).

[0039] 3. Energy consumption assessment: Quantify the energy efficiency ratio of antifreeze measures and verify their energy-saving advantages.

[0040] Experiment 1: Comparison of the effects of graded antifreeze control (winter operating conditions) Objective: To verify the timeliness and energy efficiency of the gradient response mechanism in suppressing icing.

[0041] Conditions: Wet-bulb temperature -10℃, ambient humidity 80%, wind speed 4m / s.

[0042]

[0043] As shown in the table above, the icing rate decreases significantly to 0.4 mm / h in the advanced response stage, but the energy consumption is high, indicating that the energy efficiency ratio needs to be dynamically balanced. The primary response can quickly suppress icing and is suitable for light icing conditions.

[0044] Experiment 2: Optimization of Intermittent Hot Water Pulse Antifreeze Parameters (Secondary Antifreeze Zone) Objective: To verify the effect of the inverse relationship between pulse period and wind speed on the antifreeze effect.

[0045] Conditions: Annular zone 0.8m from the tower wall, with a temperature difference of 10℃ between the inside and outside of the tower wall.

[0046]

[0047] As shown in the table above, when the wind speed increases, shortening the pulse cycle can improve the antifreeze effect and reduce energy consumption. The pulse jet duration is positively correlated with the inverse of the wind speed, which is consistent with the design logic.

[0048] Experiment 3: Performance of Winter Heat Exchange Optimization Mode (Variable Inclination Water Distribution + Delayed Water Drop) Objective: To compare the effects of different nozzle elevation angles on water droplet residence time and heat exchange efficiency.

[0049] Conditions: Winter mode, inlet water temperature 45℃, ambient temperature -5℃.

[0050]

[0051] As shown in the table above, when the elevation angle increases to 25-30 degrees, the water droplet residence time is extended, the heat exchange efficiency is improved by 17%-25%, the power consumption of the fan increases slightly, but the overall energy efficiency ratio is still better than the baseline mode.

[0052] Experiment 4: Validation of the antifreeze energy consumption assessment system Objective: To demonstrate the optimization process of dynamic energy efficiency ratio under three threshold levels.

[0053]

[0054] As shown in the table above, the energy efficiency ratio of the linkage regulation measures is the best (0.59), which meets the excellent level standard. The energy consumption of the deterioration level combination is too high, and it is necessary to switch to more efficient measures.

[0055] The experimental data above shows that: 1. Graded antifreeze control can effectively suppress icing, and advanced response should be used in conjunction with energy consumption assessment.

[0056] 2. Optimization measures such as pulse antifreeze and variable tilt angle water distribution significantly improve antifreeze and heat exchange efficiency.

[0057] 3. The dynamic energy efficiency ratio assessment system can guide the optimization of measures to achieve energy-saving goals.

[0058] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for antifreeze and heat exchange optimization and energy saving of a ventilation cooling tower, characterized in that, Includes the following steps: S1. Real-time monitoring of multiple parameters in the cooling tower, including inlet water temperature difference, outlet water temperature difference, air wet-bulb temperature, and distribution of ice thickness on the tower wall; S2. Based on the multi-region parameters, the cooling tower is dynamically divided into antifreeze priority zones, where the high-frequency vibration zone and the low-temperature air outlet zone are automatically marked as the first-level antifreeze zone. S3. Establish an anti-freezing early warning model based on historical icing data. When the icing thickness growth rate of any sub-region within the primary anti-freezing zone exceeds the preset threshold, a gradient response mechanism is triggered. S4. Implement graded antifreeze control: In the initial response stage, adjust the water spray density of this sub-area to 70%-85% of the baseline value; in the intermediate response stage, reduce the ventilation volume of adjacent areas by 10%-15%; in the advanced response stage, activate the rotating hot water curtain jet. S5. During non-freezing periods, switch the heat exchange optimization mode according to seasonal characteristics. In summer, use a combination of high water density and low circulation rate, and in winter, use a combination of variable tilt angle water distribution and delayed water drop. S6. Dynamically correct antifreeze control parameters through vortex detection feedback at the air outlet until the ice thickness drops back to the safe threshold, and establish an antifreeze energy consumption assessment system.

2. The method for antifreeze and heat exchange optimization and energy saving of a ventilation cooling tower according to claim 1, characterized in that, The division of the antifreeze priority zone in step S2 also includes setting the annular zone 0.5-1.2m away from the tower wall as the secondary antifreeze zone. This zone uses intermittent hot water pulse antifreeze, and the pulse period is inversely proportional to the real-time wind speed.

3. The method for antifreeze and heat exchange optimization and energy saving of a ventilation cooling tower according to claim 2, characterized in that, The intermittent hot water pulse antifreeze specifically includes: setting up temperature gradient detection points in the secondary antifreeze zone; when the temperature difference between the inside and outside of the tower wall is detected to be >8℃, the preheating stage of pulse antifreeze is started; after preheating for 30-60 seconds at 50% of the reference hot water flow rate, the pulse jet stage is entered; the jetting duration of the pulse jet stage is positively correlated with the reciprocal of the real-time wind speed, and the interval between single pulses is ≤120 seconds; after the pulse ends, the waste heat utilization cycle is started, and the residual hot water is introduced into the water distribution system of the adjacent non-icing zone.

4. The method for antifreeze and heat exchange optimization and energy saving of a ventilation cooling tower according to claim 3, characterized in that, The establishment of the anti-freezing early warning model in step S3 specifically includes: collecting spatiotemporal distribution data of icing locations for at least three winter operating cycles, and constructing an icing thermodynamic characteristic map, wherein the map contains a nonlinear correspondence between icing thickness and water spray density at different wet-bulb temperatures.

5. The method for antifreeze and heat exchange optimization and energy saving of a ventilation cooling tower according to claim 4, characterized in that, The construction of the freezing thermodynamic characteristic spectrum specifically includes: S31. Data stratification and collection: Historical icing data are collected according to wet-bulb temperature range. Specifically, the wet-bulb temperature range is -20℃ to 0℃, and each 2℃ range is divided into a sub-range. Each sub-range contains at least 200 valid samples. The samples include the extreme distribution of icing thickness, the gradient of water spray density at the corresponding time, and the wind speed vector. S32. Feature Correlation Modeling: Nonlinear regression analysis is performed on the icing thickness and water spray density within each wet-bulb temperature sub-interval to generate three feature curves, namely the critical icing curve, the safe operation curve, and the transition warning curve. S33. Dynamic correction mechanism: In real-time operation, when the actual freezing rate deviates from the predicted value of the spectrum by more than 15%, the following corrections are triggered: if the ambient humidity is continuously >85%, the corresponding sub-interval of the current wet-bulb temperature will be automatically lowered by 1℃; if the water hardness changes by >10%, the corresponding compensation coefficient will be added to the water spray density threshold.

6. The method for antifreeze and heat exchange optimization and energy saving of a ventilation cooling tower according to claim 5, characterized in that, The variable tilt angle water distribution in step S5 specifically includes: adjusting the elevation angle of the water distributor nozzle from 15 degrees to 25-30 degrees in winter mode to form a parabolic water droplet trajectory and extend the residence time of the water droplets in the air by 0.8-1.5 seconds.

7. The method for antifreeze and heat exchange optimization and energy saving of a ventilation cooling tower according to claim 6, characterized in that, The eddy current detection feedback in step S6 specifically includes: identifying the intensity of the eddy current at the air outlet using a Doppler anemometer; and automatically increasing the jet pressure of the hot water curtain in the first-level antifreeze zone by 5-8% when the detected eddy current intensity exceeds the critical value.

8. The method for antifreeze and heat exchange optimization and energy saving of a ventilation cooling tower according to claim 7, characterized in that, The establishment of the antifreeze energy consumption assessment system specifically includes: S61. Multi-dimensional energy consumption data calibration: Record energy consumption data according to the type of anti-freezing measures, including the cumulative flow and temperature rise energy consumption of hot water curtain spray, the change in power consumption of circulating water pump caused by water density adjustment, and the extra work done by the fan corresponding to the ventilation volume adjustment. Set a benchmark conversion factor for each type of energy consumption. Among them, the energy consumption of hot water curtain is based on the energy consumption of temperature rise in the 70-75℃ range. S62. Quantification of icing suppression effectiveness: After defining the reduction in icing thickness per unit time as the core effectiveness index, a mapping relationship library between antifreeze measures and effectiveness indexes is established. Specifically, this includes linear suppression effectiveness corresponding to individual hot water curtain spraying, stepped suppression effectiveness corresponding to the linkage adjustment of water spray density and ventilation volume, and azimuth-weighted effectiveness corresponding to the adjustment of rotary nozzle orientation. S63. Dynamic Energy Efficiency Ratio Assessment: Divide the total energy consumption of the current antifreeze measures by the real-time icing suppression efficiency to obtain the dynamic energy efficiency ratio. At the same time, set three energy efficiency thresholds: excellent, warning, and deterioration. When the energy efficiency ratio of the excellent level is ≤0.8, the current measures are maintained. When the energy efficiency ratio of the warning level is >0.8 and ≤1.2, parameter optimization is triggered. When the energy efficiency ratio of the deterioration level is >1.2, the standby mode is forcibly switched. S64. Historical data retrospective correction: Extract the execution records of anti-freezing measures every month, manually mark abnormal operating conditions, retrospectively update the mapping relationship database, and prioritize the elimination of measure combinations that trigger the degradation level three times consecutively.

9. A method for antifreeze and heat exchange optimization and energy saving of a ventilation cooling tower according to claim 8, characterized in that, The rotating hot water curtain spray in step S4 automatically adjusts the nozzle rotation speed according to the spatial distribution difference of ice thickness in the primary antifreeze zone. Specifically, sub-regions with ice thickness ≥ 5 mm correspond to a high-speed rotation mode, i.e., 15-20 r / min; sub-regions with ice thickness 3-5 mm correspond to a medium-speed rotation mode, i.e., 8-12 r / min; and sub-regions with ice thickness < 3 mm correspond to a low-speed scanning mode, i.e., 3-5 r / min. The spray coverage area maintains a dynamic buffer zone of 0.2-0.5 m from the edge of the ice area.

10. The method for antifreeze and heat exchange optimization and energy saving of a ventilation cooling tower according to claim 9, characterized in that, The delayed water droplet formation is specifically achieved by: setting a low-speed turbulent air curtain 0.8-1.2m below the water distributor, with the air speed controlled at 0.3-0.6m / s; then adjusting the nozzle orifice diameter of the water distributor to distribute the water droplet diameter in the range of 2-4mm; monitoring the water droplet falling speed in real time; and automatically increasing the tilt angle of the turbulent air curtain by 5-10 degrees when the detected speed is higher than 70% of the reference value. Finally, the water droplet cooling curve is obtained by using an infrared thermal imager, and the matching relationship between the air curtain action time and the water droplet residence time is dynamically optimized.

11. The method for antifreeze and heat exchange optimization and energy saving of a ventilation cooling tower according to claim 10, characterized in that, The specific content of triggering the gradient response mechanism in step S3 includes triggering conditions and dynamic termination. Specifically, when the real-time ice thickness growth rate of any sub-region within the first-level anti-freezing zone exceeds a preset threshold, the anti-freezing early warning model triggers the gradient response mechanism.

12. The method for antifreeze and heat exchange optimization and energy saving of a ventilation cooling tower according to claim 11, characterized in that, The conditions for dynamic termination are: triggering the termination response when the ice thickness drops to <1mm and triggering the termination response when the energy efficiency ratio is rated as excellent.

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