Cooling tower salt deposition control method and seawater cooling tower

Abstract

The invention relates to the technical field of cooling towers, in particular to a cooling tower salt deposition control method and a seawater cooling tower. The control method comprises the following steps that seawater is pumped into the cooling tower and sprayed into the cooling tower, so that convection heat exchange and evaporation heat exchange between the seawater and rising air are completed in a water distribution layer, a filler layer or a heat exchange area in the cooling tower, and wet air is formed; water drops in the wet air are coalesced and settled to a cooling tower water pool under the action of sound waves; wet air parameters, drifting spectrum data and salt deposition data in the cooling tower are obtained; and according to the wet air parameters, the drifting spectrum data, the salt deposition data and the cooling tower operation working condition, water distribution parameters and sound wave parameters are adjusted, and the cooling tower outlet drifting spectrum meets the salt deposition control requirement. The drifting spectrum of an outlet of the cooling tower is controlled by optimizing the water distribution system, using the sound wave water collector and other technical means, and therefore deposition of salt around the cooling tower is reduced, and the influence on the environment is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of cooling towers, and in particular to a cooling tower salt deposition control method and a seawater cooling tower. Background Art

[0002] As an industrial cooling system, seawater cooling towers are widely used in situations that require a large amount of cooling water, such as the power, chemical and other industries.

[0003] When cooling seawater in a seawater cooling tower, due to the evaporation of seawater, small water droplets containing salt in the moist air are discharged from the tower, forming salt deposits after diffusion. Excessive salt deposits can cause serious damage to crops and soil. At present, traditional seawater cooling towers have shortcomings in controlling salt deposition, and it is difficult to meet the strict requirements for salt deposition control by relying solely on conventional dewatering devices. A new technical solution is urgently needed to solve this problem in order to reduce the negative impact of seawater cooling tower operation on the surrounding environment.

[0004] Therefore, the existing technology has the following technical problems: ① The traditional dewatering device is inefficient and cannot effectively control salt deposition. ② Lack of comprehensive consideration of the internal structure and operating conditions of the cooling tower leads to inaccurate control of the droplet spectrum. ③ Lack of real-time monitoring and intelligent control system, unable to dynamically adjust operating parameters according to environmental changes. ④ The impact of salt deposition on the environment has not been effectively evaluated and controlled. A new technical solution is urgently needed to solve this problem in order to reduce the negative impact of seawater cooling tower operation on the surrounding environment. Summary of the invention

[0005] In view of the shortcomings of the prior art, the purpose of the embodiments of the present invention is to provide a method for controlling salt deposition in a cooling tower and a seawater cooling tower. By optimizing the water distribution system and using technical means such as an acoustic water collector, the droplet spectrum at the outlet of the cooling tower is controlled, thereby reducing the deposition of salt around the cooling tower and reducing the impact on the environment.

[0006] In order to achieve the above object, the embodiment of the present invention provides the following technical solutions:

[0007] A method for controlling salt deposition in a cooling tower comprises the following steps: pumping seawater into a cooling tower, and performing convection heat exchange and evaporation heat exchange with rising air in a water distribution layer, a packing layer and other heat exchange areas in the cooling tower to form humid air; agglomerating water droplets in the humid air and settling them into a cooling tower pool through the action of acoustic waves; obtaining humid air parameters, droplet spectrum data and salt deposition data inside the cooling tower; and adjusting water distribution parameters and acoustic wave parameters according to the humid air parameters, droplet spectrum data, salt deposition data and cooling tower operating conditions, so that the droplet spectrum at the outlet of the cooling tower meets the salt deposition control requirements.

[0008] The embodiment of the present invention also provides a seawater cooling tower, including: a water distribution system, which is used to pump seawater into the cooling tower, and the seawater completes convective heat exchange and evaporative heat exchange with the rising air in the water distribution layer, the packing layer or the heat exchange area in the cooling tower to form humid air; an acoustic water collector, which is used to cause the water droplets in the humid air to coalesce and settle into the cooling tower pool through the action of acoustic waves; a data monitoring system, which is used to obtain the humid air parameters, droplet spectrum data and salt deposition data inside the cooling tower; a control system, which is used to adjust the water distribution parameters and acoustic wave parameters according to the humid air parameters, droplet spectrum data, salt deposition data and the operating conditions of the cooling tower, so that the droplet spectrum at the cooling tower outlet meets the salt deposition control requirements.

[0009] One or more technical solutions provided in the embodiments of the present invention have at least the following technical effects or advantages:

[0010] Sound waves are used to make water droplets in the humid air condense and settle into the cooling tower pool. The water distribution parameters and sound wave parameters are adjusted according to the humid air parameters, droplet spectrum data, salt deposition data and cooling tower operating conditions, and the droplet spectrum at the cooling tower outlet is accurately controlled, which significantly reduces the settling of salt water droplets around the cooling tower and the harm of salt deposition to crops and soil, with good environmental benefits.

[0011] The ultrasonic water collector recycles some small water droplets into the cooling tower pool, reducing the waste of seawater, improving the utilization rate of water resources, and reducing the cost of seawater treatment.

[0012] The coordination of the data monitoring system and the control system enables the cooling tower to automatically adjust according to the actual operating conditions and adapt to different working conditions and environmental conditions, thus ensuring the stable and efficient operation of the cooling tower and improving the intelligence level and adaptability of the system.

[0013] Advantages of additional aspects of the present invention will be given in the following description, and in part will become obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings required for use in the embodiments or the prior art descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work. In addition, the spacing or size between the components is exaggerated to show the positions of the components, and the schematic diagram is only used for illustration.

[0015] Figure 1 It is a schematic diagram of the composition of a seawater cooling tower with controllable salt deposition provided by an embodiment of the present invention;

[0016] In the figure: 1. Cooling tower; 2. Cooling tower water pool; 3. Water distribution pipe; 4. Water pool temperature measuring point; 5. Nozzle; 6. Water eliminator; 7. Circulating water inlet temperature measuring point; 8. Central area sound wave generator; 9. Wet air dense area sound wave generator. DETAILED DESCRIPTION

[0017] It should be noted that the following detailed descriptions are illustrative and are intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used in the present invention have the same meanings as those commonly understood by those of ordinary skill in the art to which the present invention belongs. In addition, it should also be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0018] Terminology explanation:

[0019] The "droplet spectrum" refers to the size distribution of water droplets in the cooling tower, which directly affects the amount and range of salt deposition. The "sonic water collector" is a device that uses sound waves to promote the coalescence of water droplets, which can improve the droplet spectrum and reduce the discharge of water droplets.

[0020] This embodiment proposes a method for controlling salt deposition in a cooling tower, comprising the following steps: pumping seawater into the cooling tower and spraying the seawater therein, so that the seawater completes convection heat exchange and evaporation heat exchange with rising air in the water distribution layer, the packing layer or the heat exchange area in the cooling tower to form humid air; using the action of sound waves to cause water droplets in the humid air to coalesce and settle into a cooling tower pool; obtaining humid air parameters, droplet spectrum data and salt deposition data inside the cooling tower; and adjusting water distribution parameters and sound wave parameters according to the humid air parameters, droplet spectrum data, salt deposition data and the operating conditions of the cooling tower, so that the droplet spectrum at the cooling tower outlet meets the salt deposition control requirements.

[0021] The hardware used in this control method includes:

[0022] A water distribution system, which includes specially selected nozzles, which, in addition to meeting the requirements of heat exchange water distribution, are also used to form a cooling tower discharge droplet spectrum that meets the requirements of salt deposition control; wherein the specially selected nozzles are selected according to the specific structure and operating conditions of the cooling tower to produce a cooling tower discharge droplet spectrum that matches the requirements of salt deposition control.

[0023] The ultrasonic water collector is installed inside the cooling tower. It uses the action of acoustic waves to make small water droplets in the humid air aggregate into large water droplets and settle into the cooling tower pool to collect water and control the outlet droplet spectrum.

[0024] Data monitoring system, used to monitor the droplet spectrum, wet air parameters and salt deposition related data inside the cooling tower;

[0025] The control system is connected to the data monitoring system, and adjusts the water distribution parameters of the water distribution system and the operating parameters of the acoustic water collector according to the monitoring data to ensure that the droplet spectrum at the cooling tower outlet meets the salt deposition control requirements.

[0026] The selection of the nozzle of the water distribution system needs to comprehensively consider the cooling tower structure and working conditions to form a droplet spectrum that is suitable for salt deposition control and heat exchange requirements. The specific process is as follows:

[0027] Analysis and selection based on cooling tower structure

[0028] Influence of tower size and shape: First determine the diameter, height and internal shape characteristics of the cooling tower. For cooling towers with smaller diameters, select nozzles with relatively small spray angles to ensure that water droplets can be concentrated in the effective area of ​​the tower to avoid excessive dispersion and affect the effect of the sound wave. If the cooling tower is high, a nozzle with a certain spray pressure and a long range should be selected to ensure that seawater can be evenly distributed in the higher packing layer or heat exchange area to promote the full evaporation of water and the subsequent sound wave water collection process.

[0029] Basic selection model based on cooling tower size: For the cooling tower diameter (D) and height (H), the following empirical formula is used to preliminarily determine the nozzle spray angle (θ) and range (L). Spray Angle Where k1 is an empirical coefficient, which is fine-tuned according to the specific shape and internal structure of the cooling tower. k2 is another empirical coefficient.

[0030] Internal structure adaptation: Consider factors such as the layout of the water distribution pipes inside the cooling tower, the type and distribution of fillers, etc. If the water distribution pipes are distributed in a ring shape with large spacing, select nozzles that can cover a larger area, such as circular spray nozzles, whose spray range can effectively connect the water distribution areas of adjacent nozzles to ensure that the seawater is evenly distributed on the fillers. Different types of fillers, such as honeycomb fillers and corrugated fillers, have different abilities to capture and disperse water droplets. For honeycomb fillers, due to their relatively regular structure, nozzles that produce relatively small and uniform droplet sizes can be selected to better fill the filler pores, increase the contact area between water and air, and promote evaporation and subsequent sonic water collection; for corrugated fillers, nozzles with slightly larger droplet sizes but evenly distributed can be selected, and the corrugated structure can be used to guide and converge water droplets to improve water utilization efficiency and water collection effects.

[0031] Selection strategy based on cooling tower operating conditions

[0032] Seawater flow and temperature factors: adjust the nozzle orifice size and number according to the seawater flow. When the seawater flow is large, select nozzles with larger orifice diameters or more nozzles to ensure that the seawater can be sprayed in the cooling tower in a timely and uniform manner. At the same time, the seawater temperature will also affect the evaporation rate and droplet spectrum characteristics. Under high-temperature seawater conditions, the evaporation rate is fast, and the nozzle injection pressure and flow rate can be appropriately reduced to reduce excessive atomization of seawater and avoid the generation of too many tiny droplets and increase the risk of salt deposition. On the contrary, under low-temperature seawater conditions, the injection parameters can be appropriately increased to promote seawater evaporation and form a droplet spectrum that is more conducive to acoustic water collection.

[0033] Coordination of unit load and environmental conditions: Considering the matching with the unit load, when the unit is running at high load, the heat load of the cooling tower is large and the amount of seawater evaporation is large. It is necessary to select a nozzle that can produce larger droplet size and wider distribution to adapt to the situation of large amount of water evaporation, and at the same time facilitate the effect of sound waves on water droplets to improve water collection efficiency. When running at low load, you can choose a nozzle that produces smaller and relatively concentrated droplet size. On the basis of ensuring a certain amount of evaporation, reduce unnecessary seawater waste and salt deposition. In addition, the selection is combined with environmental conditions such as wind speed and humidity. In a high wind speed environment, in order to prevent the seawater from being blown away, a nozzle with a small spray angle and strong wind resistance should be selected; in a high humidity environment, the nozzle parameters should be appropriately adjusted to make the generated droplet spectrum easier to be condensed and collected by sound waves, so as to avoid the water droplets from being suspended in the tower for a long time and increasing the risk of salt deposition. By comprehensively considering these factors, the nozzle is accurately selected to form a droplet spectrum suitable for sound wave water collection, effectively controlling salt deposition and improving water resource utilization.

[0034] The installation location and number of acoustic wave generators in seawater cooling towers need to comprehensively consider the structure of the cooling tower, operating conditions, wet air distribution and other factors. The specific methods are as follows:

[0035] Installation location determination

[0036] Based on the structural analysis of the cooling tower: For natural ventilation wet cooling towers or high-level water collection cooling towers, their internal structure must be studied first. The area around the central water distribution area of ​​the cooling tower is a key part, where water evaporation and air flow disturbance are more intense, and a large amount of humid air is generated. The scope of this area is determined by measuring the geometric dimensions of the cooling tower and fluid mechanics simulation. For example, if the radius of the cooling tower is 10 meters, the annular area with a radius of 3 meters in the central water distribution area can be considered as a key area. In this annular area, according to the principles of symmetry and uniformity of the circumference, it is divided into several small areas of equal area, such as a sector area every 30 degrees, and an acoustic wave generator installation point is set in the center of each sector area or near the center and does not affect the normal operation of the water distribution system. Ensure that the sound wave can fully cover the periphery of the central water distribution area and effectively act on the humid air generated by evaporation.

[0037] Wet air distribution monitoring and positioning: Install high-precision humidity sensors and airflow velocity sensors at different heights and horizontal positions inside the cooling tower to form a monitoring network. During the operation of the cooling tower, the humidity and airflow velocity data at each position are collected in real time. Use these data to draw a three-dimensional map of the wet air volume distribution, intuitively showing the areas with high density of wet air volume distribution. For example, after a period of monitoring, it was found that in some local areas near the 1 / 2 radius of the cooling tower and the airflow rising channel, the humidity was significantly higher than other parts and the airflow velocity was large, indicating that the density of wet air volume distribution in these areas was large. Identify these areas as the key installation locations of the sound wave generator, and reasonably plan the layout of the installation points according to the size and shape of the area. For larger areas with dense wet air, a matrix or grid layout can be used to ensure that the sound waves can be evenly covered and give full play to the water collection effect.

[0038] Installation quantity determination

[0039] Consider the scale and working conditions of the cooling tower: The scale of the cooling tower has an important impact on the number of acoustic wave generators. For small cooling towers (such as cooling towers for 200MW units), the internal space is relatively small and the total amount of wet air is limited. In the vicinity of the central water distribution area and in areas with high density of wet air distribution, it may only be necessary to install 5-8 acoustic wave generators to meet the basic water collection and salt deposition control needs. For large cooling towers (such as cooling towers for 800MW units), due to the large flow of seawater they process and the large amount of wet air generated by evaporation, the number of acoustic wave generators needs to be increased accordingly. 20-30 may need to be installed around the central water distribution area, and 30-50 may need to be installed in areas with high density of wet air distribution to ensure that sufficient acoustic wave energy covers the entire interior of the cooling tower and effectively control salt deposition.

[0040] Combined with water collection efficiency and control requirements: Determine the number of acoustic wave generators based on the strictness of salt deposition control and the desired water collection efficiency. If the salt deposition control requirements are extremely high, such as in ecologically sensitive areas, more sophisticated humid air treatment is required, and the number of acoustic wave generators may need to be increased to improve the water collection effect and further reduce the discharge of salt water droplets. For example, under general control requirements, installing acoustic wave generators according to the number determined based on the scale of the cooling tower can reduce salt deposition by 60% to 70%. However, if the salt deposition is to be reduced by more than 80%, it may be necessary to increase the number of acoustic wave generators by 20% to 30% on the original basis. At the same time, combined with the goal of improving water collection efficiency, if it is expected to increase the utilization rate of water resources by more than 20%, it is also necessary to appropriately increase the number of acoustic wave generators and reasonably adjust their installation positions to ensure that the sound waves can fully act on the humid air and achieve efficient water collection and salt deposition control.

[0041] The data monitoring system monitors the relevant data in the cooling tower in the following ways:

[0042] (1) Wet air parameter monitoring

[0043] Layout of temperature and humidity sensors: Temperature and humidity sensors are evenly arranged at different heights and horizontal positions inside the cooling tower. For example, sensors are installed at the bottom, middle and top of the cooling tower, as well as near the air inlet, air outlet and central water distribution area. These sensors use high-precision capacitive or resistive sensors to quickly and accurately measure the temperature and relative humidity of humid air. After the sensor converts the measured analog signal into a digital signal, it is transmitted to the control system in real time through wired or wireless transmission methods (such as industrial Ethernet or ZigBee wireless communication protocol). Based on these data, the control system can calculate the absolute humidity, moisture content and other parameters of the humid air, understand the state changes of the humid air, provide a reference for the frequency and sound intensity adjustment of the acoustic water collector, and ensure that the sound waves can effectively act on the water droplets in a suitable humid air environment.

[0044] Application of wind speed and direction sensors: Install wind speed and direction sensors to monitor the speed and direction of airflow in cooling towers. Wind speed and direction sensors are usually installed in key locations such as airflow rising channels and air outlets. The sensors use the principles of ultrasonic or hot wire anemometers and can accurately measure wind speed and direction. These data are very important for analyzing the flow path and velocity distribution of humid air. For example, when the wind speed is high and the direction is unstable, it may affect the propagation of sound waves and the movement trajectory of water droplets. At this time, the control system can adjust the installation angle or operating parameters of the acoustic water collector according to the wind speed and direction data to ensure the water collection effect. At the same time, wind speed and direction data can also help determine the ventilation conditions in the cooling tower and optimize the operating efficiency of the cooling tower.

[0045] (2) Monitoring of salt deposition related data

[0046] Quality monitoring and analysis: Soil, vegetation and circulating water samples around the cooling tower are collected regularly for laboratory chemical analysis to determine detailed information such as salt content and ion composition. By comparing the analysis results of samples at different times, we can understand the long-term trend of salt deposition and its impact on the surrounding environment. For example, soil samples are collected at different locations around the cooling tower every month to analyze the changes in the content of major salts such as sodium chloride and magnesium chloride. At the same time, the circulating water samples are subjected to total salt analysis and ion chromatography analysis to understand the accumulation and changes of salt in the circulating water, provide more comprehensive data support for the operation optimization and maintenance of the cooling tower, and ensure effective control of the harm of salt deposition to the environment.

[0047] The classification definition of operating conditions and the method of nozzle selection are as follows:

[0048] Definition of operating condition classification

[0049] Seasonal classification: It can be divided into summer, winter, spring and autumn. In summer, the temperature is high, the evaporation of seawater is large, the humidity of humid air is high and the heat load in the cooling tower is large; in winter, the temperature is low, the evaporation of seawater is small, the humidity of humid air is low and the heat load is small; spring and autumn are in between, with moderate evaporation and heat load. For example, in summer, the ambient temperature may reach 30-40℃, and the seawater temperature is relatively high, while in winter, the ambient temperature may drop to 0-10℃, or even below zero, and the seawater temperature will drop accordingly. These temperature differences will significantly affect the evaporation process and droplet spectrum characteristics of seawater in the cooling tower.

[0050] Unit load classification: divided into high load (such as the unit operating power reaches 80% to 100% of the rated power), medium load (50% to 80%) and low load (less than 50%). At high load, the cooling tower needs to handle a large amount of heat, the seawater evaporates quickly, and the requirements for water distribution and water collection are high; at low load, the heat exchange demand is reduced, and the seawater evaporation and droplet spectrum also change accordingly.

[0051] Determine the nozzle selection according to the operating conditions of the cooling tower

[0052] Basic selection model based on cooling tower size: For the cooling tower diameter (D) and height (H), the following empirical formula is used to preliminarily determine the nozzle spray angle (θ) and range (L). Spray Angle Where k1 is an empirical coefficient, which is fine-tuned according to the specific shape and internal structure of the cooling tower. k2 is another empirical coefficient.

[0053] Adjustment model combining season and load: Further modify the nozzle parameters under different seasons and loads. Take the water spray volume (Q) as an example. Under high load conditions in summer, Where Q0 is the water spray volume under standard working conditions, T sea is the sea water temperature, T ref is the reference temperature (such as 25°C), k3 is the temperature influence coefficient, and k4 is the load influence coefficient. Under low load conditions in winter, k5 is the temperature influence coefficient, k6 is the load influence coefficient. According to the calculated water spray volume, select the nozzle with the appropriate spray hole size and number.

[0054] The operating parameters of the sonic eliminator and nozzle are adjusted based on the following algorithm model:

[0055] Data preprocessing and working condition identification

[0056] Parameter standardization: First, process the collected droplet spectrum data and convert the droplet size distribution into specific mathematical features, such as average particle size, particle size standard deviation, volume proportion of different particle size segments, etc. For temperature and humidity data, normalize them so that they are in the range of 0-1. For example, if the actual temperature range is 10-40°C, it can be normalized by the formula. The salt deposition amount sets a threshold value based on the design capacity of the cooling tower and the sensitivity of the surrounding environment. For example, salt deposition exceeding a certain value is considered to be excessive.

[0057] Classification and matching of working conditions: Classify the operating conditions according to factors such as season and unit load. For example, define the high-load working condition in summer as working condition 1, and the low-load working condition in winter as working condition 2, etc. Match the currently collected parameters with the pre-set standard parameter ranges under different working conditions to determine the specific working condition currently in. For example, under working condition 1, determine the specific standard average particle size range, humidity range, etc. If the currently collected average particle size and humidity parameters are within this range, it is determined to be working condition 1.

[0058] Operation parameter adjustment

[0059] Adjustment of the frequency f and sound intensity I of the acoustic water collector: The frequency and sound intensity are determined based on the droplet spectrum and working conditions. avg When it is less than the preset value and in working condition 1, a higher frequency is used, such as Where f1 is the basic frequency and k1 is the frequency adjustment coefficient. At the same time, sound intensity I=I1+k2×(V small -V small1 ), where V small is the volume proportion of small-size droplets, V small1 is the standard volume proportion of small particle size droplets under working condition 1, I1 is the basic sound intensity, and k2 is the sound intensity adjustment coefficient. This is because when there are more small particle size droplets, a higher sound intensity is required to promote their agglomeration. On the contrary, when the average particle size is greater than the predetermined value and in working condition 2, the frequency is reduced, f = f2-k3×D avg , f2 is the basic frequency under working condition 2, k3 is the coefficient, and the sound intensity is also reduced accordingly, I=I2+k4×(V large -V large2 ), V large is the volume proportion of large-size droplets, V large2 is the standard volume proportion of large-size droplets under working condition 2, I2 is the basic sound intensity under working condition 2, and k4 is the coefficient.

[0060] Nozzle pressure (P) and spray angle (α) adjustment: adjust nozzle parameters according to salt deposition control standards and droplet spectrum. When the salt deposition approaches or exceeds the threshold S thWhen the proportion of larger particle size droplets in the droplet spectrum is low (large particle size and small particle size are relative values, and the particle size and proportion can be divided and determined according to the specific situation), increase the nozzle pressure. Where P0 is the initial pressure, k5 and k6 are pressure adjustment coefficients, V large3 is the current volume proportion of large-size droplets. At the same time, adjust the spray angle to make it more concentrated on the areas inside the cooling tower that are prone to salt deposition, such as α0 is the initial injection angle, and k7 is the angle adjustment coefficient. When the salt deposition is low (that is, when the droplet spectrum required by the set salt deposition threshold is close, that is, when the salt deposition basically meets the requirements) and the droplet spectrum meets the standard, appropriately reduce the nozzle pressure and adjust the injection angle to a state that is more conducive to uniform water distribution, such as, and k8 and k9 are the corresponding adjustment coefficients. By continuously comparing the collected data with the working conditions, the above model is used to dynamically adjust the operating parameters to ensure that the droplet spectrum at the cooling tower outlet meets the salt deposition control requirements, achieving efficient operation and environmental protection effects.

[0061] like Figure 1 As shown, it is a schematic diagram of the composition of a seawater cooling tower with controllable salt deposition, wherein a cooling tower water pool 2 is provided at the bottom of the cooling tower 1, and a water pool temperature measuring point 4 is provided in the cooling tower water pool 2. A circulating water inlet temperature measuring point 7 is provided on the water spraying pipe 3, and a nozzle 5 is provided at the inner end of the water spraying pipe 3. A dewaterer 6, a central area sound wave generator 8, and a wet air dense area sound wave generator 9 are provided in the cooling tower 1.

[0062] Seawater cooling towers with controlled salt deposition include:

[0063] The cooling tower body is a natural ventilation wet cooling tower or a high-level water collection cooling tower.

[0064] The water distribution system has nozzles selected according to the cooling tower structure and operating conditions to form a droplet spectrum that adapts to the heat exchange requirements and salt deposition control requirements.

[0065] The ultrasonic water collector is installed inside the cooling tower. It uses sound waves to cause small water droplets in the humid air to coalesce and settle into the cooling tower pool, thereby controlling the droplet spectrum at the cooling tower outlet.

[0066] The data monitoring system is used to monitor the droplet spectrum, wet air parameters and salt deposition related data in the cooling tower.

[0067] The control system is connected to the data monitoring system, and adjusts the water distribution parameters of the water distribution system and the operating parameters of the acoustic water collector according to the monitoring data to ensure that the droplet spectrum at the cooling tower outlet meets the salt deposition control requirements.

[0068] The nozzle selection is determined by analyzing and calculating the structure and operating conditions of the cooling tower to produce a droplet spectrum that meets the heat exchange requirements and salt deposition control requirements. The acoustic water collector uses a device that can adjust the sound wave frequency and sound intensity, and can be adaptively adjusted according to different droplet spectra and operating conditions.

[0069] The data monitoring system includes a droplet spectrum analyzer for predicting the droplet spectrum, a temperature and humidity sensor for measuring the temperature and humidity of wet air, and a salinity sensor for detecting the amount of salt deposition, and the data monitoring system can transmit data to the control system in real time.

[0070] The control system stores standard data of droplet spectra and salt deposition control standards under different working conditions, and intelligently controls the water distribution system and the sonic water collector by comparing the monitoring data with the standard data using a preset algorithm.

[0071] The seawater cooling tower achieves control of salt deposition by optimizing the water distribution system, installing high-efficiency water collectors such as sonic water collectors, and coordinating the various components to effectively control the droplet spectrum at the cooling tower outlet, thereby solving the problems existing in the prior art and reducing the negative impact of the operation of the seawater cooling tower on the surrounding environment. At the same time, it ensures the cooling performance of the cooling tower and achieves the dual goals of environmental protection and efficiency.

[0072] Example 1

[0073] Cooling tower installation and commissioning

[0074] The technology of the present invention was implemented on a natural ventilation seawater cooling tower supporting a 500MW unit in a coastal area. A specially designed swirl nozzle was selected as the nozzle of the water distribution system, and 20 acoustic water collectors were evenly arranged inside the cooling tower. Each acoustic water collector was equipped with an independent acoustic frequency and sound intensity adjustment device. After the installation was completed, the data monitoring system was debugged to ensure that the temperature and humidity sensors and salinity sensors could accurately collect the droplet spectrum, wet air parameters and salt deposition related data inside the cooling tower, and stably transmit these data to the control system.

[0075] Parameter setting and model building

[0076] According to the design specifications of the cooling tower and local environmental conditions, the standard range of the droplet spectrum and the upper limit of salt deposition control under different seasons and unit loads are set in the control system. Through preliminary tests and theoretical calculations on the cooling tower, a mathematical model between nozzle selection, acoustic water collector operating parameters and droplet spectrum control is established and embedded in the control system, so that the control system can automatically adjust the operating parameters of the water distribution system and acoustic water collector according to the data monitoring results.

[0077] Running Tests

[0078] During the full-load operation of the unit in summer, the data monitoring system collects real-time data from the cooling tower. When it is found that the proportion of large-size water droplets in the droplet spectrum is low, which is not conducive to the efficient operation of the acoustic water collector, the control system adjusts the nozzle pressure and injection angle of the water distribution system according to the preset model to optimize the droplet spectrum. At the same time, according to the humidity and temperature changes of the humid air, the sound wave frequency and sound intensity of the acoustic water collector are adjusted to improve the water collection efficiency. After a period of operation, it was monitored that the droplet spectrum at the outlet of the cooling tower met the salt deposition control requirements, and the salt deposition was reduced by 60% compared with the traditional cooling tower. At the same time, the cooling performance of the cooling tower was stable, and there was no decrease in cooling efficiency due to the operation of the water collection device.

[0079] Example 2

[0080] System upgrade and expansion

[0081] The present invention was applied to a high-level seawater cooling tower for a larger 800MW unit, and the system was upgraded. A more advanced intelligent nozzle was used, which could quickly adjust the water spray volume and droplet size distribution according to the instructions of the control system. At the same time, the number and accuracy of sensors in the data monitoring system were increased, and multiple salinity sensors were set at different locations around the cooling tower to more accurately monitor salt deposition. In addition, a visual droplet monitoring device was installed at the outlet of the cooling tower so that the operator could intuitively understand the droplet spectrum.

[0082] Personalized parameter optimization

[0083] In view of the characteristics of the 800MW unit and cooling tower, the mathematical model in the control system was further optimized through a large number of simulation calculations and field tests. Taking into account the impact of local sea breeze direction and wind speed on salt deposition, meteorological data was introduced into the control system as a reference factor to adjust the operation strategy of the water distribution system and the sonic water collector. For example, during periods of strong sea breeze, the water spray volume of the nozzle is appropriately increased and the power of the sonic water collector is improved to ensure the control effect of salt deposition.

[0084] Actual operation effect During the long-term operation of the unit, the seawater cooling tower with controllable salt deposition of the present invention has achieved remarkable results. Under various working conditions, the droplet spectrum at the outlet of the cooling tower is always kept within the salt deposition control requirements, and the salt deposition amount is reduced by 70% on average, effectively protecting the surrounding ecological environment. At the same time, by optimizing the water collection process, the water resource utilization rate of the cooling tower is increased by 15%, providing reliable technical support for the efficient and environmentally friendly operation of the seawater cooling tower, and has broad application prospects and promotion value.

[0085] It can be seen from the above embodiments that the seawater cooling tower with controllable salt deposition of the present invention can effectively control salt deposition in practical applications while ensuring the normal operation of the cooling tower, and has important practical value and environmental significance.

[0086] 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 method for controlling cooling tower salt deposition, characterized in that: The following steps are involved: Pumping seawater into the cooling tower and spraying it, so that the seawater can complete convection heat exchange and evaporation heat exchange with the rising air in the water distribution layer, filler layer or heat exchange area in the cooling tower to form humid air; The water droplets in the moist air are coalesced and settled into the cooling tower pool through the action of sound waves; Obtain the wet air parameters, droplet spectrum data and salt deposition data inside the cooling tower; According to the wet air parameters, droplet spectrum data, salt deposition data and cooling tower operating conditions, the water distribution parameters and acoustic wave parameters are adjusted so that the droplet spectrum at the cooling tower outlet meets the salt deposition control requirements.

2. The cooling tower salt deposition control method according to claim 1, characterized in that: Seawater is sprayed into the cooling tower through a water distribution system, which includes a nozzle. The spray angle, spray pressure and range of the nozzle are determined according to the size and shape of the tower body; the coverage area and water droplet size of the nozzle are determined according to the internal structure of the cooling tower; the size and number of the nozzle holes and the spray pressure and flow of the nozzle are determined according to the seawater flow and temperature; the water droplet size and coverage area of ​​the nozzle and the spray angle of the nozzle are determined according to the unit load and environmental conditions; the spray angle of the nozzle is determined according to the ratio of the height and diameter of the cooling tower, and the range of the nozzle is determined according to the square root of the product of the height and diameter of the cooling tower.

3. The cooling tower salt deposition control method according to claim 1, characterized in that: The sound waves are generated by the sound wave generator. The installation position of the sound wave generator is determined according to the cooling tower structure and the distribution of wet air. The installation quantity of the sound wave generator is determined according to the cooling tower scale and operating conditions, water collection efficiency and control requirements.

4. The cooling tower salt deposition control method according to claim 1, characterized in that: The wet air parameters include temperature, humidity, wind speed and direction of air flow; temperature and humidity sensors are installed at the bottom, middle and top of the cooling tower, as well as at the air inlet, outlet and central water distribution area; wind speed and direction sensors are installed in the air flow rising channel and outlet of the cooling tower.

5. The cooling tower salt deposition control method according to claim 1, characterized in that: Obtaining salt deposition data includes: regularly collecting soil, vegetation and circulating water samples around the cooling tower, conducting laboratory chemical analysis, determining the salt content and ion composition, and comparing sample analysis results at different times to obtain the long-term change trend of salt deposition and its impact on the surrounding environment.

6. The cooling tower salt deposition control method according to claim 1, characterized in that: The operating conditions are divided according to the season and unit load. The season is divided into summer, winter and spring and autumn, and the unit load is divided into high load, medium load and low load. The unit operating power reaches 80% to 100% of the rated power for high load, 50% to 80% for medium load, and less than 50% for low load.

7. The cooling tower salt deposition control method according to claim 6, characterized in that: Nozzle water spray volume Among them, Q0 is the water spray volume under standard working conditions, T sea is the sea water temperature, T ref is the reference temperature, k3 is the temperature influence coefficient, k4 is the load influence coefficient, k3 and k4 are determined according to the season and unit load, and the nozzle hole size and number are selected according to the water spray volume.

8. The method for controlling cooling tower salt deposition according to claim 6, characterized in that: Determine the frequency and sound intensity of the acoustic water collector based on the droplet spectrum and operating conditions: When the average particle size D avg When the frequency of the acoustic water collector is less than the preset value and in the high load condition in summer, Where f1 is the basic frequency, k1 is the frequency adjustment coefficient, and sound intensity I = I1 + k2 × (V small -V small1 ), where V small is the volume proportion of small-size droplets, V small1 is the standard volume proportion of small-size droplets under high-load conditions in summer, I1 is the basic sound intensity, and k2 is the sound intensity adjustment coefficient; when the average particle size is greater than the predetermined value and under low-load conditions in winter, f=f2-k3×D avg , f2 is the basic frequency under low load conditions in winter, k3 is the coefficient, I=I2+k4×(V large -V large2 ), V large is the volume proportion of large-size droplets, V large2 is the standard volume proportion of large-size droplets under low-load conditions in winter, I2 is the basic sound intensity under low-load conditions in winter, and k4 is the coefficient.

9. The cooling tower salt deposition control method according to claim 6, characterized in that: According to the salt deposition control standard and the drift droplet spectrum, the nozzle parameters are adjusted. When the salt deposition exceeds the threshold S th When the proportion of larger droplets in the droplet spectrum is low, the nozzle pressure increases. Where P0 is the initial pressure, k5 and k6 are pressure adjustment coefficients, V large3 is the current volume proportion of large-size droplets; when adjusting the spray angle to make it more concentrated in the area inside the cooling tower that is prone to salt deposition, the spray angle α0 is the initial spray angle, k7 is the angle adjustment coefficient; when the salt deposition is low and the droplet spectrum meets the standard, reduce the nozzle pressure and adjust the spray angle to a state that is more conducive to uniform water distribution. and k8 and k9 are the corresponding adjustment coefficients.

10. A seawater cooling tower, characterized in that: include: The water distribution system pumps seawater into the cooling tower and sprays it, so that the seawater can complete the convection heat exchange and evaporation heat exchange with the rising air in the water distribution layer, packing layer or heat exchange area in the cooling tower to form humid air; The sonic water collector is used to make the water droplets in the humid air coalesce and settle into the cooling tower pool through the action of sonic waves; Data monitoring system, used to obtain the wet air parameters, droplet spectrum data and salt deposition data inside the cooling tower; The control system is used to adjust the water distribution parameters and the acoustic wave parameters according to the wet air parameters, the droplet spectrum data, the salt deposition data and the cooling tower operation conditions, so that the droplet spectrum at the cooling tower outlet meets the salt deposition control requirements.

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