Demisting water-saving natural ventilation wet cooling tower and working method

Abstract

The invention discloses a demisting water-saving natural ventilation wet cooling tower and a working method, the cooling tower comprises a cooling tower body, a filler, a water distribution system, a dehydrator and a plurality of sound wave generators are arranged in the cooling tower body, and the sound wave generators are mounted at the upper part and the nearby area of a water distribution tank maintenance channel in the cooling tower; the sound wave generators are distributed in a high-humidity air flow area, a high-water-drop-content area, a medium-humidity air flow area and a medium-water-drop-content area. The sound wave generator adjusts the frequency and the sound intensity to the maximum extent according to the water drop characteristics, the environmental conditions and the water collecting efficiency; a certain proportion of water is recycled according to different working conditions through the sound wave water collecting technology, waste of water resources is effectively reduced, and the water saving effect is more prominent when the unit operates at low load; and meanwhile, when the water is recovered, the generation of fog plumes around the cooling tower is reduced, the surrounding environment is improved, and the potential influence of the fog plumes on peripheral equipment and facilities is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of cooling towers, and in particular to a demisting and water-saving natural ventilation wet cooling tower and a working method thereof. Background Art

[0002] There are two types of water loss in cooling towers: one is the evaporation of water generated by the cooling of the cooled water during the cooling process of the cooling tower, and the other is the small water droplets carried by the water vapor being taken out of the tower during the cooling process. In industrial production, especially in the field of coal-fired power units, cooling towers are important heat dissipation equipment. The function of the cooling tower is to exchange heat between the cooling water carrying waste heat and the air in the tower, so that the waste heat carried by the hot water is transferred to the cold air and discharged into the atmosphere. Especially in the cooling towers of larger power plants, the layout of various cooling towers is to arrange hot water to flow downward from the spray, and the air to flow vertically upward from the bottom. After the air cools the hot water, it flows out from the top of the cooling tower. When the air directly cools the hot water, it will produce a considerable amount of water vapor and carry some small water droplets out of the cooling tower, causing water resource loss. Although water vapor in many power plants has to pass through a dehydrator before leaving the tower, because most of the current dehydrators are unpowered bending plates, water droplets are only recovered and removed through the physical collision mechanism, so the dehydration efficiency is not high. Even if the structure and material of the bending plate are changed, there is still a lot of water vapor carrying small water droplets flowing out, and the amount of water loss is still very large.

[0003] Therefore, traditional wet cooling towers have a large amount of water loss during operation, resulting in a waste of water resources. At the same time, the mist plume generated during the operation of the cooling tower will also have a certain impact on the surrounding environment. At present, there is an urgent need for a new cooling tower that can effectively save water and reduce the generation of mist plume to meet the requirements of industrial production for energy conservation and environmental protection. Summary of the invention

[0004] In view of the problems existing in the prior art, the present invention provides a demisting and water-saving natural ventilation wet cooling tower and a working method. By adopting the acoustic wave water collection technology, a sound wave generator is arranged inside the cooling tower. The operating parameters of the sound wave generator are statically determined according to the operating parameters of the cooling tower, and the operating state of the sound wave generator is dynamically adjusted to achieve the effect of saving water and reducing fog plume, thereby improving the water-saving performance and environmental protection performance of the cooling tower.

[0005] The technical solution of the present invention is as follows:

[0006] In a first aspect of the present invention, a demisting and water-saving natural ventilation wet cooling tower is provided, comprising a cooling tower body, wherein fillers, a water distribution system, a dewatering device and a plurality of sound wave generators are arranged in the cooling tower body, wherein the sound wave generators are installed in the upper part and the vicinity of the water distribution tank inspection channel inside the cooling tower, and the plurality of sound wave generators are distributed in a high-humidity air flow area, a high-water droplet content area, a medium-humidity air flow area and a medium-water droplet content area; the sound wave generator determines and adjusts the frequency emission angle, frequency and sound intensity according to the water droplet characteristics, environmental conditions and water collection efficiency maximization.

[0007] In some embodiments of the present invention, the sound wave generator is fixed to the water distribution tank maintenance channel and the surrounding area by an adjustable hanging bracket and a modular fixed frame respectively. The adjustable hanging bracket includes a telescopic rod, one end of which is fixed to a steel beam on the upper part of the water distribution tank maintenance channel, and the other end is connected to a rotating disc. The rotating disc fixes the sound wave generator by a slot and bolts. The adjustable hanging bracket can place the sound wave generator within a certain distance on both sides of the water distribution tank maintenance channel through the telescopic rod.

[0008] In some embodiments of the present invention, the modular fixed frame includes a plurality of identical square frames, the four corners of the square frames are provided with mounting holes and adjustable positioning bolts, the sound wave generator is fixed in the square frame, the square frame is fixed on the base connecting seat at the upper part of the water distribution tank maintenance channel, and the modular fixed frame can fix the sound wave generator on the steel frame of the water distribution tank maintenance channel.

[0009] In some embodiments of the present invention, a transmission system is provided on the basic connecting seat, and the transmission system drives the sound wave generator to rotate to adjust the emission angle of the sound wave generator.

[0010] In some embodiments of the present invention, flow sensors and temperature sensors are provided on the water inlet pipe and the water outlet pipe of the cooling tower, a wet air temperature sensor, a humidity sensor and a wind speed sensor are also provided inside the cooling tower, and a temperature sensor and an anemometer are provided outside the cooling tower.

[0011] In a second aspect of the present invention, a method for operating a demisting and water-saving natural ventilation wet cooling tower is provided, comprising:

[0012] A three-dimensional model of a cooling tower is established, and the internal flow field of the cooling tower is simulated. According to the simulation results, the interior of the cooling tower is divided into multiple areas, including a high-humidity air flow area, a high-water droplet content area, a medium-humidity air flow area, a medium-water droplet content area, and a low-humidity air flow area, a low-water droplet content area. An acoustic wave generator is installed in the high-humidity air flow area, the high-water droplet content area, the medium-humidity air flow area, and the medium-water droplet content area;

[0013] During the operation of the cooling tower, the operating conditions of the cooling tower, the water temperature entering the tower, the flow rate entering the tower, the ambient temperature and the ambient wind speed, as well as the humidity, temperature and wind speed of the humid air in the tower are obtained. Based on the above data and the preset algorithm in the control system, the characteristics of the humid air inside the cooling tower under the current working conditions are calculated. The control system adjusts the frequency and sound intensity of the sound wave generator based on the calculation results and the preset water collection rate.

[0014] In some embodiments of the present invention, when simulating the internal flow field of the cooling tower, the wet air volume flow rate is used as the inlet boundary condition, and the wet air volume flow rate is calculated by the following formula:

[0015]

[0016] Where V air is the volume flow rate of wet air; Q is the heat load entering the tower; r is the latent heat of evaporation of water; c p is the specific heat of air; v wind is the ambient wind speed; T env is the ambient temperature; R is the gas constant; P is the pressure in the cooling tower; ΔT is the temperature change value; α and β are correction coefficients.

[0017] In some embodiments of the present invention, the control system adjusts the height and horizontal angle of the sound wave generator according to the acquired data.

[0018] In some embodiments of the present invention, the control system determines and adjusts the frequency and sound intensity of the sound wave generator according to the characteristics of the water droplets, environmental conditions, and the maximum water collection rate.

[0019] In some embodiments of the present invention, during the operation of the cooling tower, the preset water collection rate is dynamically adjusted according to different operating conditions of the cooling tower.

[0020] One or more technical solutions of the present invention have the following beneficial effects:

[0021] (1) The demisting and water-saving natural ventilation wet cooling tower provided by the present invention realizes a certain proportion of water recovery according to different working conditions through the ultrasonic water collection technology, effectively reducing the waste of water resources. When the unit is running at low load, combined with the adjustment of the circulating water system, the water-saving effect is more prominent; at the same time, while recycling water, the generation of fog plumes around the cooling tower is reduced, the surrounding environment is improved, and the potential impact of fog plumes on surrounding equipment and facilities is reduced.

[0022] (2) In the demisting and water-saving natural ventilation wet cooling tower provided by the present invention, when installing the sound wave generator, the installation position of the sound wave generator is determined according to the simulation results, and the sound wave generator is installed by means of an adjustable suspension bracket and a modular fixed frame. The adjustable suspension bracket can adjust the position of the sound wave generator, and the sound wave emission angle of the sound wave generator can be adjusted by means of a set gear transmission system. During the operation of the cooling tower, the position and angle of the sound wave generator can be adjusted as needed, thereby maximizing the amount of water collected.

[0023] (3) The demisting and water-saving natural ventilation wet cooling tower provided by the present invention can, during operation, automatically adjust the operating state of the sound wave generator in real time according to a variety of operating parameters by using a data acquisition system and a control system, thereby ensuring that the cooling tower is always in an efficient and water-saving operating mode, thereby improving the intelligence level and operating stability of the cooling tower. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a schematic diagram of a demisting and water-saving natural ventilation wet cooling tower of the present invention;

[0025] Figure 2 It is a distribution diagram of the installation of the sound wave generator of the present invention.

[0026] In the figure: 1. Cooling tower body; 2. Cooling tower pool; 3. Water distribution system; 4. Pool temperature measuring point; 5. Ground; 6. Ground environmental parameter measuring point; 7. Circulating water inlet temperature measuring point; 8. Central area sound wave generator; 9. High humidity air flow area sound wave generator; 10. High humidity air flow area; 11. Water distribution trough inspection channel; 12. Cooling tower central area; 13. Water eliminator; 14. Filling. DETAILED DESCRIPTION

[0027] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0028] Example 1

[0029] In a typical embodiment of the present invention, a demisting and water-saving natural ventilation wet cooling tower is proposed, such as Figure 1 and Figure 2 As shown, it includes a cooling tower body 1, in which a filler 14, a water distribution system 3, a water remover 13 and a plurality of sound wave generators 9 are arranged. The sound wave generator 9 is installed on the upper part and the vicinity of the water distribution tank inspection channel 11 inside the cooling tower, and the plurality of sound wave generators are distributed in a high-humidity air flow area, a high-water droplet content area, a medium-humidity air flow area, and a medium-water droplet content area; the sound wave generator determines and adjusts the frequency and sound intensity according to the water droplet characteristics, environmental conditions and water collection efficiency maximization.

[0030] In this embodiment, the sound wave generator is fixed on the water distribution tank maintenance channel 11 and the surrounding area through an adjustable hanging bracket and a modular fixed frame. The adjustable hanging bracket can place the sound wave generator within a certain distance on both sides of the water distribution tank maintenance channel through a telescopic rod to achieve an optimal layout. The modular fixed frame can fix the sound wave generator on the steel frame of the water distribution tank maintenance channel.

[0031] The adjustable suspension bracket is made of high-strength aluminum alloy, including a vertical telescopic rod, one end of which is fixed to the steel beam at the top of the water distribution tank inspection channel, and the other end is connected to a rotating disc, and the rotating disc is fixed to the sound wave generator through a slot and bolts. Specifically, the top of the telescopic rod is fixed to the steel beam at the top of the water distribution tank inspection channel by bolts. A tightening knob is provided on the telescopic rod to facilitate precise height adjustment. A 360-degree rotatable disc is connected to the bottom of the telescopic rod, and the sound wave generator is fixed to the disc through a slot and bolts. This structure allows the height and horizontal angle of the sound wave generator to be flexibly adjusted according to the needs of different areas inside the cooling tower, ensuring that the sound waves can effectively cover the periphery of the central water distribution area and areas with high density of humid air distribution.

[0032] The modular fixed frame is made of stainless steel, and the modular fixed frame includes a plurality of identical square frames, and the four corners of the square frames have mounting holes and adjustable positioning bolts, and the sound wave generator is fixed in the square frame, and the square frame is fixed on the basic connection seat at the upper part of the water distribution tank inspection channel. Specifically, the modular frame is composed of a plurality of identical small modules. Each small module is designed as a square frame, and the four corners of the square frame have mounting holes and adjustable positioning bolts. Some basic connection seats are pre-welded or bolted at the predetermined installation position at the upper part of the water distribution tank inspection channel, and these connection seats are adapted to the mounting holes of the modular frame. During installation, the sound wave generator is fixed in the small module of the modular frame, and then the modules of appropriate number and position are selected for splicing and installation according to the distribution of humid air inside the cooling tower. This method is convenient for installation, disassembly and maintenance. If a certain sound wave generator fails, it only needs to disassemble the corresponding small module to replace it, without large-scale disassembly of the entire installation structure.

[0033] An existing transmission system is provided on the mounting base of the acoustic wave generator. The system is controlled manually or electrically. When the acoustic wave emission angle needs to be adjusted, the control system (or the operator manually operates the control device) issues a command, and the drive motor drives the rotating shaft to rotate, which can achieve full-range rotation adjustment from 0 to 360 degrees; in the vertical direction, the angle adjustment range can reach -45 to +45 degrees, which is enough to cover areas of different heights and orientations inside the cooling tower, ensuring that the acoustic waves can accurately act on key areas such as areas with high density of humid air volume distribution and the periphery of the central water distribution area of ​​the cooling tower. Both the adjustable suspension bracket and the modular fixed frame can be realized using existing structures.

[0034] In this embodiment, the water inlet pipe and the water outlet pipe of the cooling tower are both provided with flow sensors and temperature sensors, the interior of the cooling tower is also provided with a wet air temperature sensor, a humidity sensor, and a wind speed sensor, and the exterior of the cooling tower is provided with a temperature sensor and an anemometer. The above sensors are connected to the control system as a data acquisition system, and the control system is used to control the frequency, intensity, and emission angle of the sound wave generator according to the data collected by the above sensors.

[0035] Specifically, the flow sensor and temperature sensor are installed at the circulating water inlet temperature measuring point 7, the wet air temperature sensor and humidity sensor, and the wind speed sensor are installed in the space above the water distribution tank near the water distribution tank, and the cooling tower water pool 2 is arranged at the bottom of the cooling tower body 1. A liquid level meter is installed at the water pool temperature measuring point of the cooling tower water pool 2 to detect the water collection amount. A temperature sensor and anemometer are arranged at the ground environmental parameter measuring point 6 of the ground 5 around the cooling tower body 1 to monitor environmental parameters.

[0036] When installing the sound wave generator, use the following installation method:

[0037] (1) Partition positioning installation: First, the airflow field and humid air distribution inside the cooling tower are analyzed in detail using computational fluid dynamics simulation software. According to the simulation results, the interior of the cooling tower is divided into multiple areas, such as high-humidity air flow area, high water droplet content area, medium-humidity air flow area, medium water droplet content area, and low-humidity air flow area, low water droplet content area. Positioning marks are set at key locations in each area, and the installers accurately install the sound wave generator on the upper part of the water distribution trough inspection channel according to these marks. For example, in the high-humidity air flow area and high-water droplet content area, a sound wave generator is installed at a certain angle (such as 30 degrees) to ensure that the sound wave covers the area evenly; in the medium-humidity air flow area and medium water droplet content area, the sound wave generator is installed relatively densely in places with higher concentrations according to the humid air concentration gradient to improve the water collection efficiency.

[0038] (2) Dynamic adjustment of installation: In addition to the initial installation positioning, the installation position of the sound wave generator is dynamically adjusted in combination with real-time monitoring data and the predetermined water collection rate. Wet air temperature sensors, humidity sensors, and wind speed sensors are installed at different locations inside the cooling tower, and the sensor data is transmitted to the control system in real time. The control system determines the changes in the distribution of wet air based on data analysis. If the amount of wet air in a certain area increases significantly and requires stronger sound waves, the control system will issue a command to adjust the parameters and emission angle of the sound wave generator through a motor drive or hydraulic device. For example, when it is found that wet air gathers in a certain local area in the tower during a specific period of time, the frequency and sound intensity of the nearby sound wave generator can be increased to enhance the treatment effect on wet air and realize intelligent dynamic installation adjustment.

[0039] Implementation Method 1

[0040] 1. Cooling tower installation and commissioning

[0041] The demisting and water-saving system of the present invention is installed on a natural ventilation wet cooling tower supporting a 350MW coal-fired power unit. Ten sound wave generators are evenly installed in the medium-humidity air flow area and the medium-water droplet content area inside the cooling tower, and 15 sound wave generators are installed in the high-humidity air flow area and the high-water droplet content area. After the installation is completed, various sensors of the data acquisition system are connected, including power sensors, calorimeters, temperature sensors and wind speed sensors, and these sensors are connected and debugged with the control system to ensure accurate data acquisition and stable transmission.

[0042] 2. Parameter setting and model building

[0043] According to the historical operation data of the coal-fired power unit and the design parameters of the cooling tower, the water collection rate of the unit is set to 15% during normal operation and 30% during low-load operation in the control system. At the same time, according to the structure and fluid mechanics characteristics of the cooling tower, combined with the theoretical model of the influence of environmental factors on the amount of wet air, a wet air volume calculation model suitable for the cooling tower is established and embedded in the control system.

[0044] 3. Run the test

[0045] During a complete operation cycle of the coal-fired power unit, including normal load operation and peak load operation, the operation of the cooling tower is monitored. When the unit is operating at a normal load of 300MW, the data acquisition system collects parameters such as the load of the coal-fired power unit, the heat load entering the cooling tower, the ambient temperature and the ambient wind speed in real time, and transmits them to the control system. The control system calculates the amount of humid air inside the cooling tower based on these parameters, determines that the number of sound wave generators that need to be turned on is 18, and adjusts the sound wave frequency and sound intensity to the preset initial optimization value. After running for a period of time under this condition, it is found that the water collection rate of the cooling tower has reached 14.5%, the amount of fog plume generated has been significantly reduced, and the humidity of the surrounding environment has been reduced.

[0046] When the unit enters the low-load 150MW operation stage, the control system recalculates the amount of wet air and the number of acoustic wave generators to be turned on according to the new operating parameters, changes it to 10, and further optimizes the acoustic wave frequency and sound intensity. After a period of operation monitoring, the water collection rate of the cooling tower reached 32%, and the water-saving effect was significantly improved. At the same time, the cooling effect of the cooling tower was stable, and there was no negative impact on the cooling efficiency due to the operation of the acoustic wave generator.

[0047] Implementation Method 2

[0048] 1. System upgrade and expansion

[0049] The technology of the present invention is applied to a larger scale 600MW coal-fired power unit's natural ventilation wet cooling tower, and the system is upgraded. The number of acoustic wave generators is increased to 50, and more advanced sensors and control systems are used to improve the accuracy of data acquisition and the response speed of control.

[0050] 2. Personalized parameter optimization

[0051] According to the characteristics of the 600MW unit and cooling tower, the water collection rate, wet air volume calculation model and the control strategy of the acoustic generator are optimized through the analysis and test of the previous operation data. When the unit is operating normally, the water collection rate is set to 18%, and the parameters in the calculation model are dynamically adjusted according to different seasons and environmental conditions. For example, in the high temperature and high humidity environment in summer, the estimation of the wet air volume is appropriately increased to ensure the best operation effect of the acoustic generator.

[0052] 3. Actual operation effect

[0053] During the long-term operation of the unit, the demisting and water-saving natural ventilation wet cooling tower of the present invention exhibits good performance. Under normal operating conditions, the average water collection rate is stabilized at about 17.5%, and the mist plume concentration is reduced by 40%, effectively improving the environment around the cooling tower. When the unit is running at low load, the water collection rate can reach up to 38%, and the operating stability of the cooling tower is guaranteed, providing strong support for energy saving and consumption reduction and environmental protection operation of coal-fired power units.

[0054] It can be seen from the above embodiments that the demisting and water-saving natural ventilation wet cooling tower of the present invention can effectively recover evaporated water according to different working conditions in practical applications, reduce the generation of fog plumes, has significant water-saving and environmental protection effects, and operates stably and reliably, and has broad application prospects and promotion value.

[0055] Example 2

[0056] In a typical embodiment of the present invention, a working method of a demisting and water-saving natural ventilation wet cooling tower is provided, comprising:

[0057] Step 1: Establish a three-dimensional model of the cooling tower and simulate the internal flow field of the cooling tower. According to the simulation results, the interior of the cooling tower is divided into multiple areas: high-humidity air flow area, high water droplet content area, medium-humidity air flow area, medium water droplet content area, low-humidity air flow area, low water droplet content area, and install an acoustic wave generator in each area.

[0058] When simulating the internal flow field of the cooling tower, the wet air volume flow rate is used as the inlet boundary condition. The wet air volume flow rate is calculated by the following formula:

[0059]

[0060] Where V air is the volume flow rate of wet air; Q is the heat load entering the tower; r is the latent heat of evaporation of water; c p is the specific heat of air; v wind is the ambient wind speed; T env is the ambient temperature; R is the gas constant; P is the pressure in the cooling tower; ΔT is the temperature change value; α and β are correction coefficients.

[0061] The calculation formula of wet air volume flow rate is derived as follows:

[0062] According to the principles of thermodynamics and heat and mass transfer, the volume flow rate of wet air (V air ) calculation involves multiple parameters. First, the tower heat load (Q) and the latent heat of evaporation of water (r), air mass flow rate (m air ) and specific heat of air (c p ) and temperature change (ΔT). The inlet heat load (Q) can be measured by measuring the inlet water temperature (Tin ), outlet water temperature (T out ) and circulating water flow (m water ), using the formula Q = m water c water (T in -T out ) is calculated, where c water is the specific heat capacity of water. Ambient temperature (T env ) and ambient wind speed (v wind ) is directly measured by the temperature sensors and wind speed sensors installed around the cooling tower. Air specific heat (c p ), the latent heat of evaporation of water (r), the gas constant (R), etc. are known physical constants and can be taken according to actual conditions. The pressure (P) can be approximated to the local atmospheric pressure or can be accurately measured by installing a pressure sensor.

[0063] Assuming that the evaporation process of water in the cooling tower is approximately an adiabatic saturation process, according to the law of energy conservation, we can get: Q = m air (c p ΔT+r). At the same time, the ideal gas state equation PV=mRT (where P is pressure, V is volume, m is mass, R is gas constant, and T is temperature) can be transformed into By combining these two equations and taking into account the ambient temperature (T env ) and ambient wind speed (v wind ) on the heat and mass transfer coefficients, and by introducing correction coefficients α and β (determined by experiments or empirical data), the calculation formula for the wet air volume flow rate can be obtained as follows:

[0064] Computational fluid dynamics software was used to simulate the flow field inside the cooling tower. The calculated wet air volume flow rate was used as the inlet boundary condition, and a three-dimensional model was established in combination with the geometric structure of the cooling tower, the information of internal components (such as fillers, water distribution system, etc.) and the air flow velocity distribution. Through simulation calculations, the distribution of parameters such as air flow velocity, temperature, and humidity at different locations inside the cooling tower was obtained, thereby determining the distribution of the wet air volume in the cooling tower. For example, around the 1 / 2 radius area of ​​the cooling tower, the amount of wet air is relatively large due to the more intense evaporation of water and air flow disturbance; while near the cooling tower wall, the air flow velocity is relatively low and the amount of wet air may be small.

[0065] According to the numerical calculation results of the cooling tower, the interior of the cooling tower is divided into several areas, including high humidity air flow area, high water drop content area, medium humidity air flow area, medium water drop content area, low humidity air flow area, low water drop content area, etc. Monitoring points are set in each area to measure parameters such as humidity, temperature, and wind speed. Combined with the calculated humid air volume flow, the humid air volume in each area is statistically analyzed. At the same time, based on the empirical data accumulated from long-term operation, the distribution of humid air volume in each area under different working conditions is corrected and improved. For example, when operating at high load, the proportion of humid air volume in the central water distribution area may increase, while when operating at low load, the humid air volume in this area is relatively reduced. By summarizing and applying these changing rules, the distribution of humid air volume can be determined more accurately, providing a basis for the subsequent control of the acoustic wave generator.

[0066] Step 2: During the operation of the cooling tower, obtain the operating conditions of the cooling tower, inlet water temperature, inlet flow, ambient temperature and ambient wind speed. According to the preset water collection rate and the above data combined with the preset algorithm in the control system, calculate the characteristics of the humid air inside the cooling tower under the current working conditions. The control system adjusts the frequency and sound intensity of the sound wave generator according to the calculation results.

[0067] The control system determines and adjusts the frequency and sound intensity of the acoustic generator according to the characteristics of the water droplets, environmental conditions and the maximum water collection rate.

[0068] Specifically, the adjustment method is as follows:

[0069] Automatic adjustment based on sensor data feedback: The control system obtains parameters such as the load of the coal-fired power unit, the water temperature entering the tower, the water volume entering the tower, the ambient temperature, and the ambient wind speed through the data acquisition system. Using these data, combined with the established mathematical model and algorithm, and combined with the preset water collection rate, the characteristics of the humid air inside the cooling tower under the current working conditions, such as the amount of humid air, humidity distribution and other information, are calculated. Based on these calculation results, the control system sends instructions to the sound wave generator to adjust its frequency and sound intensity. For example, when it is detected that the water temperature entering the tower is high and the ambient wind speed is low, it may mean that the water in the cooling tower evaporates faster and the humid air diffuses relatively slowly. At this time, the control system may appropriately increase the frequency and sound intensity of the sound waves to enhance the condensation of water droplets and promote water collection.

[0070] Phased adjustment strategy: During the operation of the cooling tower, adjustments are made according to different operation stages. In the initial startup, the control system may start the acoustic generator at a lower frequency and sound intensity to avoid water droplet breakage or excessive vibration of the equipment due to excessive energy input. As the operating time increases and the internal conditions of the cooling tower are further understood, the frequency and sound intensity are gradually adjusted to a more optimal range based on real-time monitoring data.

[0071] Adjustment principles:

[0072] Droplet characteristics: Consider the initial size and concentration of the droplets in the cooling tower. If the droplet size is small, a lower frequency and higher sound intensity are usually required to induce the droplets to obtain enough energy to collide and merge. Because small droplets are light, they can produce larger vibration amplitudes at lower frequencies, and higher sound intensity can increase the probability of collision. Conversely, for larger droplets, higher frequencies and relatively lower sound intensity can be used to enhance the relative motion and collision effects between droplets.

[0073] Environmental conditions: Adjust in combination with ambient temperature, humidity and airflow. In a high temperature environment (such as 30-40°C), due to the low air viscosity and small resistance to water droplet movement, the sound intensity can be appropriately reduced; at the same time, in a high humidity environment (such as humidity greater than 80%), new water droplets are easy to form, and in order to avoid water droplet breakage, the sound intensity should also be appropriately reduced. In a low temperature (such as 10-20°C) and low humidity (such as humidity less than 40%) environment, the sound intensity needs to be increased to compensate for the increased resistance to water droplet movement and the loss of water droplets due to evaporation. In a low airflow velocity (such as less than 0.2m / s), the sound intensity can be appropriately reduced.

[0074] Maximize water collection efficiency: During the adjustment process, always aim to achieve the maximum water collection. The control system fine-tunes the frequency and sound intensity by continuously monitoring the water collection effect, such as the amount of water collected. If it is found that the water collection efficiency is not significantly improved or shows a downward trend under the current settings, adjust the frequency and sound intensity in time. For example, when the water collection rate has not increased for a period of time, the control system can try different combinations within a certain range, observe the changes in the water collection effect, and find the best frequency and sound intensity settings.

[0075] Furthermore, the control system calculates the optimal emission angle of the sound wave generator under the current working condition according to the acquired data, and adjusts the horizontal angle and vertical angle of the sound wave generator according to the humidity distribution.

[0076] Specifically, a variety of monitoring equipment such as wet air temperature sensors, humidity sensors, and air flow velocity sensors are installed at key locations inside the cooling tower. These sensors collect environmental parameters in different areas of the cooling tower in real time and transmit the data to the control system. The control system analyzes and processes these data and uses a pre-set algorithm to determine the operating parameters (frequency and sound intensity) of the sound wave generator under the current working conditions. Always maintain the best water collection effect. For example, when it is detected that the humidity of the wet air on one side of the cooling tower suddenly increases and the droplet size becomes smaller, indicating that the area needs a stronger sound wave effect, the control system will immediately calculate the corresponding sound wave frequency and sound intensity to enhance the processing capacity of the wet air in this area.

[0077] During the operation of the cooling tower, the self-learning function of the control system adjusts and optimizes the preset water collection rate and calculation model in the following ways:

[0078] 1. Data collection and analysis

[0079] Continuous monitoring of operating parameters: The control system continuously collects multi-dimensional data such as the load of the coal-fired power unit, the water temperature entering the tower, the water volume entering the tower, the ambient temperature, the ambient wind speed, the humidity and temperature at different locations inside the cooling tower, and the actual water collection volume. These data are collected and stored at certain time intervals (such as once a minute) to form a huge operation database. For example, during the operation of the cooling tower, the power sensor monitors the load changes of the coal-fired power unit in real time, the temperature sensor accurately measures the water temperature entering the tower and the ambient temperature, the humidity sensor is distributed at key locations inside the cooling tower to monitor humidity changes, and the flow meter installed at the water collection device records the actual water collection volume.

[0080] Data correlation mining: Use data analysis algorithms (such as multivariate linear regression, principal component analysis, etc.) to conduct in-depth mining of the collected data to find potential correlations between various parameters. For example, through analysis, it is found that there is a positive correlation between the water temperature entering the tower and the amount of humid air, that is, the higher the water temperature entering the tower, the larger the amount of humid air; at the same time, the ambient wind speed is positively correlated with the diffusion range of the fog plume. The greater the wind speed, the farther the fog plume spreads, but the impact on the water collection rate is more complicated. Within a certain wind speed range, appropriate wind speed helps to improve the water collection rate, but after exceeding a certain critical value, the increase in wind speed will lead to a decrease in the water collection rate. Through these correlation analyses, a basis is provided for subsequent model optimization.

[0081] 2. Optimization and adjustment of water recovery rate

[0082] Dynamic adjustment based on working conditions: The preset water collection rate is dynamically adjusted according to different operating conditions (such as normal operation of the unit, low-load operation, high-load operation, and environmental conditions in different seasons). When the unit is operating normally, if the data analysis shows that the current ambient temperature and humidity are relatively stable, but the actual water collection rate is lower than the preset value, the control system will gradually increase the preset water collection rate and increase the number of sound wave generators turned on or adjust their frequency and sound intensity accordingly. For example, when the actual water collection rate is lower than the preset 15% for a week, and the ambient temperature is around 25°C and the humidity is around 50% with small fluctuations, the control system will increase the preset water collection rate to 16% and observe the water collection effect. On the contrary, if the water collection rate is too high and may affect the cooling effect of the cooling tower, the water collection rate is appropriately reduced. Under low-load operating conditions, due to the reduction of heat load, water evaporation is relatively reduced. If the actual water collection rate is higher than the preset high value (such as 40%), the water collection rate can be appropriately reduced to avoid excessive energy consumption and unnecessary pressure on the equipment; if it is lower than the preset low value, the intensity of water collection measures is increased.

[0083] Feedback control and iterative optimization: Apply the adjusted water collection rate to the actual operation control and continuously monitor the water collection effect. Analyze and judge again based on the new water collection data. If the water collection effect is still not ideal, continue to adjust the water collection rate to form an iterative optimization process. For example, after one adjustment of the water collection rate, if the water collection rate does not increase significantly or shows a downward trend in the next week, the control system will further analyze the reasons, such as whether the performance of the acoustic wave generator has declined, the environmental conditions have changed suddenly, etc., and adjust the water collection rate again according to the analysis results until a relatively ideal water collection effect is achieved and the operation is stable.

[0084] 3. Computational model optimization

[0085] Model parameter correction: For the calculation model for calculating the heat load entering the cooling tower and the amount of internal humid air, the key parameters are corrected according to the data analysis results. For example, in the original calculation model, the influence coefficient of the ambient wind speed on the amount of humid air may be a fixed value set based on experience, but through actual operation data, it is found that there are large differences in this coefficient in different seasons and cooling tower operating conditions. In the summer when the temperature is high and the humidity is high and the wind speed is high, the effect of wind speed on the amount of humid air is more significant. At this time, the control system will increase the coefficient according to the data fitting results; and in the winter when the temperature is low and the humidity is low and the wind speed is low, the coefficient will be reduced accordingly. Similarly, the correlation parameters between the water temperature entering the tower and the amount of humid air, the parameters affecting the internal structure of the cooling tower on the airflow and humid air distribution, etc., are dynamically corrected according to the actual operation data.

[0086] Improvement of model structure: If new important influencing factors are found in the data mining process or the existing model cannot accurately describe certain complex physical processes, the control system will improve the structure of the calculation model. For example, it is found that the type and age of the filler inside the cooling tower have an important impact on the distribution of humid air volume and water collection effect, but the original model does not consider this factor. At this time, parameters about the filler characteristics and related calculation modules will be added to the model to rebuild the model structure. The improved model is applied to actual control after verification and testing, further improving the prediction and control accuracy of the cooling tower operation status, thereby improving the water collection efficiency and operation stability.

[0087] Although the above describes the specific implementation mode of the present invention in conjunction with the accompanying drawings, it is not intended to limit the scope of protection of the present invention. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art on the basis of the technical solution of the present invention without creative work are still within the scope of protection of the present invention.

Claims

1. A demisting and water-saving natural ventilation wet cooling tower, characterized in that: The invention comprises a cooling tower body, wherein fillers, a water distribution system, a water remover and a plurality of sound wave generators are arranged in the cooling tower body, wherein the sound wave generators are installed in the upper part and the vicinity of the water distribution tank inspection channel inside the cooling tower, and the plurality of sound wave generators are distributed in a high-humidity air flow area, a high-water droplet content area, a medium-humidity air flow area and a medium-water droplet content area; the sound wave generators determine and adjust the frequency emission angle, frequency and sound intensity according to the water droplet characteristics, environmental conditions and water collection efficiency maximization.

2. The demisting and water-saving natural ventilation wet cooling tower according to claim 1, characterized in that: The sound wave generator is fixed to the water distribution tank maintenance channel and the surrounding area through an adjustable hanging bracket and a modular fixed frame respectively. The adjustable hanging bracket includes a telescopic rod, one end of which is fixed to the steel beam at the upper part of the water distribution tank maintenance channel, and the other end is connected to a rotating disc. The rotating disc fixes the sound wave generator through a slot and bolts. The adjustable hanging bracket can place the sound wave generator within a certain distance on both sides of the water distribution tank maintenance channel through the telescopic rod.

3. The demisting and water-saving natural ventilation wet cooling tower according to claim 2, characterized in that: The modular fixed frame includes a plurality of identical square frames, and the four corners of the square frames are provided with mounting holes and adjustable positioning bolts. The sound wave generator is fixed in the square frame, and the square frame is fixed on the basic connecting seat at the upper part of the water distribution tank inspection channel. The modular fixed frame can fix the sound wave generator on the steel frame of the water distribution tank inspection channel.

4. The demisting and water-saving natural ventilation wet cooling tower according to claim 3, characterized in that: The basic connecting seat is provided with a transmission system, and the transmission system drives the sound wave generator to rotate so as to adjust the emission angle of the sound wave generator.

5. The demisting and water-saving natural ventilation wet cooling tower according to claim 1, characterized in that: The water inlet pipe and the water outlet pipe of the cooling tower are both provided with flow sensors and temperature sensors. The interior of the cooling tower is also provided with a wet air temperature sensor, a humidity sensor and a wind speed sensor. The exterior of the cooling tower is provided with a temperature sensor and an anemometer.

6. A method for operating a demisting and water-saving natural ventilation wet cooling tower as claimed in any one of claims 1 to 5, characterized in that: include: A three-dimensional model of a cooling tower is established, and the internal flow field of the cooling tower is simulated. According to the simulation results, the interior of the cooling tower is divided into multiple areas, including a high-humidity air flow area, a high-water droplet content area, a medium-humidity air flow area, a medium-water droplet content area, and a low-humidity air flow area, a low-water droplet content area. An acoustic wave generator is installed in the high-humidity air flow area, the high-water droplet content area, the medium-humidity air flow area, and the medium-water droplet content area; During the operation of the cooling tower, the operating conditions of the cooling tower, the water temperature entering the tower, the flow rate entering the tower, the ambient temperature and the ambient wind speed, as well as the humidity, temperature and wind speed of the humid air in the tower are obtained. Based on the above data and the preset algorithm in the control system, the characteristics of the humid air inside the cooling tower under the current working conditions are calculated. The control system adjusts the frequency and sound intensity of the sound wave generator based on the calculation results and the preset water collection rate.

7. The operating method of the demisting and water-saving natural ventilation wet cooling tower according to claim 6, characterized in that: When simulating the internal flow field of the cooling tower, the wet air volume flow rate is used as the inlet boundary condition. The wet air volume flow rate is calculated by the following formula: Where V air is the volume flow rate of wet air; Q is the heat load entering the tower; r is the latent heat of evaporation of water; c p is the specific heat of air; v wind is the ambient wind speed; T env is the ambient temperature; R is the gas constant; P is the pressure in the cooling tower; ΔT is the temperature change value; α and β are correction coefficients.

8. The operating method of the demisting and water-saving natural ventilation wet cooling tower according to claim 6, characterized in that: The control system adjusts the height and horizontal angle of the sound wave generator according to the acquired data.

9. The operating method of the demisting and water-saving natural ventilation wet cooling tower according to claim 6, characterized in that: The control system determines and adjusts the frequency and sound intensity of the acoustic generator according to the characteristics of the water droplets, environmental conditions, and the maximum water collection rate.

10. The operating method of the demisting and water-saving natural ventilation wet cooling tower according to claim 6, characterized in that: During the operation of the cooling tower, the preset water collection rate is dynamically adjusted according to the different operating conditions of the cooling tower.

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