Fouling early warning method and system based on salt guide function of flue gas concentration tower of thermal power plant

Abstract

The application discloses a kind of based on thermal power plant flue gas concentration tower salt guide function's scale warning method, comprising: S1, the standardization collection specification of making concentrated salt water total salt content and conductivity;S2, build high salt conductivity temperature compensation system;S3, establish the salt guide function model under normal operating condition;S4, real-time monitoring concentrated salt water total salt content and standard conductivity in concentration tower;S5, according to the change of salt guide coefficient to judge scale state;S6, according to scale state carries out grading early warning, comprising: according to the judgment result of the scale state, the scale risk of concentration tower is graded early warning, and corresponding countermeasures are matched, realize the accurate prevention and control of scale.There are also disclosed corresponding evaluation system, device, electronic equipment and computer readable storage medium.

Description

Technical Field

[0001] This invention relates to the field of high-salinity wastewater treatment technology in thermal power plants, specifically to a scaling early warning method and system based on the salt derivative function of flue gas thickening towers in thermal power plants, applicable to scaling monitoring and early warning during the treatment of high-salinity wastewater from flue gas thickening towers in thermal power plants. Background Technology

[0002] With the deepening of the national ecological civilization construction, thermal power plants, as major contributors to industrial wastewater discharge, are required to implement near-zero discharge projects for high-salinity wastewater. The treatment of high-salinity wastewater has become a crucial link in achieving environmental compliance for thermal power plants. Currently, near-zero discharge of high-salinity wastewater from thermal power plants mainly involves two processes: concentration and reduction, and drying and crystallization. The mainstream technologies include thermal and membrane methods. Membrane treatment processes have high requirements for wastewater pretreatment, high construction and maintenance costs, and complex operation procedures, which greatly limits their practical application in thermal power plants. Thermal processes, depending on the medium used for concentration and drying, are further divided into steam concentration and crystallization and flue gas concentration and drying.

[0003] Steam concentration and crystallization technology mainly includes mechanical steam recompression, low-temperature multi-effect distillation, multi-stage flash evaporation, and evaporation crystallization. However, this technology suffers from high investment costs, complex wastewater pretreatment processes, high daily operating costs, and difficulties in effectively disposing of crystalline salts, failing to meet the low-cost, high-efficiency high-salinity wastewater treatment needs of thermal power plants. Therefore, flue gas concentration and drying technology, with its advantages of adaptability to thermal power plant flue gas resources, low investment, and simple process, has become the mainstream application technology for achieving zero discharge of high-salinity wastewater in thermal power plants in recent years.

[0004] In the flue gas concentration and drying process of thermal power plants, flue gas concentration and evaporation technology is the core application technology. Depending on the location of the process implementation and the method of utilizing flue gas temperature, it is mainly divided into two categories: bypass flue gas concentration tower + main flue gas evaporation and drying, and bypass flue gas concentration tower + bypass flue gas evaporation and drying. The core treatment process is as follows: high-salt wastewater, such as desulfurization wastewater from thermal power plants, is collected in a wastewater tank and transported to a bypass flue gas concentration tower for concentration and volume reduction. The concentrated brine then enters a concentrated brine treatment device for turbidity removal, and is then injected into the main flue or bypass flue through a high-salt water pump. The high temperature of the flue gas is used to evaporate and dry the concentrated brine, ultimately achieving zero discharge of high-salt wastewater.

[0005] However, the desulfurization wastewater from thermal power plants is itself a saturated CaSO4 solution. During the continuous concentration process in the thickener, the solution gradually becomes a supersaturated CaSO4 solution, leading to systemic scaling in the thickener. This is a critical technical bottleneck that urgently needs to be addressed in the current application of flue gas concentration and drying processes. In actual operation, large amounts of CaSO4 crystal scale deposits appear at the outlet of the circulating pump, spray pipes and nozzles, agitator pumps, tower walls, and tower bottom of the thickener. Severe scaling can cause the circulating pump to malfunction, flue gas temperature to become uncontrollable, and ultimately the thickener system must be frequently shut down for emergency repairs, seriously affecting the continuous and stable operation of the high-salt wastewater treatment system in thermal power plants. Furthermore, CaSO4 crystal scale is hard and difficult to clean manually; some severely scaled pipes even require direct replacement, resulting in significant equipment and labor costs.

[0006] Currently, the industry mainly uses periodic shutdowns for cleaning to control scaling in flue gas thickeners of thermal power plants, lacking effective online monitoring and early warning mechanisms. Because scaling can occur suddenly, periodic cleaning cannot accurately match the scaling process. Too short a cleaning cycle increases downtime and maintenance costs; too long a cycle leads to scale buildup causing equipment failure and greater economic losses. Therefore, developing an early warning method that can accurately and in real-time assess the scaling status of thickeners, enabling early identification and tiered control of scaling, is crucial for solving the scaling problem in flue gas thickeners of thermal power plants and a core research direction for promoting the stable operation of zero-discharge projects for high-salinity wastewater from thermal power plants.

[0007] In existing technologies, some studies attempt to assess scaling risk by monitoring single parameters such as solution concentration and temperature. However, due to the complex composition of desulfurization wastewater, which contains not only a large number of easily soluble ions such as Na+ and Cl-, but also insoluble ions that easily form precipitates, such as Ca2+ and SO42-, as well as other ions such as Mg2+ and colloidal and suspended impurities such as gypsum particles and dust, a single parameter cannot accurately reflect the actual situation of crystallization in the solution, resulting in low early warning accuracy. Other technologies indirectly assess scaling by monitoring equipment operating parameters (such as circulating pump pressure and flue gas flow rate). However, this type of method is a passive monitoring after scaling has occurred; by the time abnormal equipment operating parameters appear, scaling has already formed and caused some equipment impact, making early warning impossible. Summary of the Invention

[0008] The purpose of this invention is to overcome the shortcomings of existing technologies and provide a scaling early warning method and system based on the salt conductivity function of flue gas thickeners in thermal power plants. Starting from the intrinsic correlation between total salt content and conductivity during the concentration of desulfurization wastewater, this invention studies and summarizes the changing characteristics of the relationship between conductivity and total salt content in concentrated brine, establishing the salt conductivity ratio function relationship between non-scaling and scaling states. This enables accurate evaluation and early warning of scaling conditions in the thickener operation, filling the technological gap in early warning of scaling in flue gas thickeners within the industry. It solves the technical problems of existing thermal power plant flue gas thickeners lacking effective early warning methods, having low early warning accuracy, and incurring high operating costs due to passive post-scaling treatment. This invention, by establishing standardized parameter acquisition specifications, a salt conductivity function model, and scaling judgment criteria, achieves accurate identification and graded early warning of precipitated crystals in the thickener, predicting scaling risks in advance, providing a time window for scaling prevention and control, effectively reducing system downtime for emergency repairs, and lowering operation and maintenance costs.

[0009] The first aspect of this invention is to provide a scaling early warning method based on the salt derivative function of a flue gas thickener in a thermal power plant, comprising:

[0010] S1. Establish standardized sampling specifications for total salt content and conductivity of concentrated brine;

[0011] S2, Construct a high-salt conductivity temperature compensation system;

[0012] S3, Establish the salt derivative function model under normal operating conditions;

[0013] S4, real-time monitoring of the total salt content and standard conductivity of the concentrated brine in the concentration tower;

[0014] S5, determine the scaling state based on the change in salt conductivity coefficient;

[0015] S6, classify and issue early warnings based on the scaling status, including: classifying and issuing early warnings on the scaling risk of the concentration tower based on the judgment result of the scaling status, and providing corresponding countermeasures to achieve precise control of scaling.

[0016] Preferably, S1 includes:

[0017] S11. The total salinity of concentrated brine is measured according to the measurement method of "Determination of Total Salinity in Water - Gravimetric Method" (HJ / T51-1999). The sampling volume is determined based on the actual total salinity range of the water sample, and standardized dilution is performed. When the total salinity of the water sample is in the range of 20000 mg to 50000 mg / L, an accurate 50.00 ml sample is taken, diluted to 100.00 ml, and then the total salinity is measured. When the total salinity of the water sample is ≥50000 mg / L, an accurate 10.00 ml sample is taken, diluted to 100.00 ml, and then the total salinity is measured. All water samples are measured in parallel. If the relative error of the parallel sample measurement results is >0.5%, it is determined that there is an error in the sampling or detection, and resampling and measurement are required.

[0018] S12, conductivity measurement includes: direct measurement of the actual conductivity of high saline sample at 45℃.

[0019] Preferably, S2 includes:

[0020] S21. High-salinity water samples with a total salt content in the range of 80,000 mg / L to 250,000 mg / L were selected as test water samples.

[0021] S22, the temperature compensation coefficient of 6 sets of parallel data was determined. The determination process was as follows: first, the initial conductivity of the test water sample at 25℃ was measured, then the water sample was heated to a predetermined temperature in the range of 40℃-48℃, and then the water sample was allowed to cool naturally to the predetermined temperature. The actual conductivity of the water sample at the predetermined temperature was measured. The conductivity temperature compensation coefficient at the corresponding temperature was obtained by calculating the initial conductivity and the actual conductivity.

[0022] S23, obtains the standardized temperature compensation coefficients for each temperature in the range of 40℃-48℃;

[0023] S24, Set temperature adjustment requirements: If the actual temperature of the collected concentrated saline sample exceeds the range of 40℃-48℃, adjust the water sample temperature to the specified temperature range by stirring and heating or cooling before conducting conductivity measurement to ensure the matching of the test data with the temperature compensation coefficient.

[0024] Preferably, the standardized temperature compensation coefficients corresponding to each temperature within the range of 40℃-48℃ in step S23 are specifically set as follows: 0.0188 for 48℃ and 47℃, 0.0190 for 46℃, 0.0191 for 45℃, 0.0192 for 44℃, 0.0193 for 43℃, 0.0194 for 42℃, and 0.0195 for 41℃ and 40℃.

[0025] Preferably, S3 includes:

[0026] S31, collect data, including: collect data on the total salt content and conductivity of concentrated brine at 45℃ under normal operating conditions of flue gas concentration towers in thermal power plants, without precipitation crystals or scaling. Data collection needs to cover different operating periods and different concentration ratios.

[0027] S32, Model fitting is performed, including: using the least squares method to fit the collected total salt content and conductivity data to obtain the power function relationship between total salt content and conductivity under normal operating conditions. This power function is the salt conductivity function of the concentration tower under normal operating conditions.

[0028] S33, Model validation, including: conducting tests and validations in the flue gas enrichment tower systems of three or more different thermal power plants, ensuring that the total salt content and conductivity of each system exhibit a stable power function relationship, and that the goodness of fit R² of the power function formula to the original data is between 93.14% and 95.8%; and performing residual analysis on the fitting results.

[0029] S34, Determine the salt conductivity threshold, including: calculating the salt conductivity K based on the fitted data; under normal operating conditions, setting the salt conductivity K > 2200 as the salt conductivity threshold for normal operation of the concentration tower; the calculation formula for the salt conductivity K is shown in the following formula (1):

[0030] (1).

[0031] Preferably, S4 includes:

[0032] S41, in accordance with the standardized collection specifications established in S1, the concentrated brine in the concentration tower is sampled in real time. The total salt content detection strictly follows the requirements of sampling, dilution, and parallel sample determination. The conductivity detection first determines whether the actual temperature of the water sample is within the range of 40℃-48℃. If it exceeds this range, it is adjusted to this range by a temperature regulating device.

[0033] S42, combined with the high-salt conductivity temperature compensation system constructed by S2, selects the corresponding temperature compensation coefficient according to the actual temperature of the water sample, and performs temperature correction on the measured conductivity to obtain the standard conductivity at 45℃.

[0034] Preferably, S5 includes:

[0035] S51, Calculate the real-time salt conductivity coefficient, including: based on the total salt content monitored in real time in S4 and the standard conductivity at 45°C, obtain the real-time salt conductivity coefficient during the operation of the concentration tower according to the same calculation method as in S3;

[0036] S52, determine the scaling state judgment criteria and determine the scaling state judgment result based on the scaling state judgment criteria, wherein the scaling state judgment criteria include:

[0037] In the early stages of scaling, if the real-time salt conductivity coefficient drops from the normal threshold of K > 2200 to below 2000 and shows a rapid decreasing trend within a short period of time, the thickener is considered to have entered the early stage of scaling. At this time, CaSO4 begins to precipitate and crystallize in the thickener, and the power function relationship between total salt content and conductivity begins to fail. In the case of severe scaling, if the real-time salt conductivity coefficient K continues to decrease and eventually stabilizes between 800-1000, the thickener is considered to have experienced severe scaling. At this time, the power function relationship between total salt content and conductivity completely fails and instead exhibits obvious linear function characteristics. Moreover, the higher the concentration ratio, the lower the salt conductivity coefficient.

[0038] Preferably, the graded early warning system for scaling risk in the concentration tower includes:

[0039] When it is determined to be the initial stage of scaling, a Level 1 warning is issued. The warning methods include on-site audible and visual alarms, SMS reminders from maintenance personnel, and pop-up notifications in the system background. The response measures for the Level 1 warning are: immediately reduce the concentration ratio of the concentration tower, reduce the concentration rate of high-salt wastewater, inhibit the formation of CaSO4 supersaturated solution, and delay the process of precipitating crystallization.

[0040] When severe scaling is detected, a Level II warning is issued. The warning method is based on the Level I warning, with the addition of a central control alarm from the power plant's environmental protection operation and maintenance center. The response measures for the Level II warning are: immediately stop the operation of the thickening tower and carry out a comprehensive scaling cleaning of the thickening tower's circulating pump outlet, spray pipes and nozzles, disturbance pump, tower walls, and tower bottom.

[0041] A second aspect of the present invention also provides a scaling early warning system based on the salt derivative function of a flue gas thickening tower in a thermal power plant, comprising:

[0042] The standardized data acquisition module (101) is used to develop standardized data acquisition specifications for total salt content and conductivity of concentrated brine.

[0043] A high-salt conductivity temperature compensation system construction module (102) is used to construct a high-salt conductivity temperature compensation system;

[0044] The salt derivative function model establishment module (103) is used to establish the salt derivative function model under normal operating conditions;

[0045] A total salt content and standard conductivity monitoring module (104) is used to monitor the total salt content and standard conductivity of the concentrated brine in the concentration tower in real time.

[0046] The scaling condition judgment module (105) is used to judge the scaling condition based on the change in salt conductivity coefficient;

[0047] The graded early warning module (106) is used to provide graded early warning based on the scaling status, including: providing graded early warning for the scaling risk of the concentration tower based on the judgment result of the scaling status, and providing corresponding countermeasures to achieve precise control of scaling.

[0048] A third aspect of the present invention also provides a scaling early warning device based on the salt derivative function of a flue gas thickening tower in a thermal power plant, comprising:

[0049] The water sampling unit is used to sample and pretreat concentrated brine in the flue gas concentration tower of a thermal power plant in real time according to the standardized sampling specifications in step S1. The water sampling unit is equipped with a sampling bottle, a dilution device, a temperature control device, and sampling tubing. The sampling bottle is a 1L glass bottle or a polyethylene plastic bottle. The dilution device is a high-precision quantitative dilution instrument. The temperature control device includes a stirrer, a heating module, and a cooling module, used to precisely adjust the temperature of the concentrated brine sample to a specified range of 40℃-48℃. The sampling tubing is made of anti-scaling material.

[0050] The detection and analysis unit, connected to the water sample collection unit, is used for the accurate detection of total salinity and conductivity of the pretreated concentrated saline sample. The detection and analysis unit includes a gravimetric total salinity analyzer and a conductivity analyzer. The gravimetric total salinity analyzer is designed according to the testing standard "Determination of Total Salinity in Water - Gravimetric Method" (HJ / T51-1999), supporting automatic sampling, automatic drying, and automatic weighing. It can achieve synchronous measurement of parallel samples and automatically calculate the relative error of parallel samples. When the relative error > 0.5%, the instrument automatically issues a prompt signal for resampling. The conductivity analyzer is a high-precision portable conductivity meter that measures the conductivity of concentrated saline samples at different temperatures. The instrument has a built-in temperature sensor to detect the actual temperature of the water sample in real time and is linked with the temperature compensation coefficient table of the data processing unit to automatically select the corresponding temperature compensation coefficient to correct the measured conductivity for temperature, obtaining the standard conductivity at 45℃.

[0051] A data processing unit, connected to the detection and analysis unit, is used to receive total salt content and conductivity detection data transmitted by the detection and analysis unit, and to perform data processing, model fitting, and salt conductivity coefficient calculation. The data processing unit is an industrial-grade computer with built-in data processing software, a salt conductivity function fitting module, a temperature compensation module, and a salt conductivity coefficient calculation module. The data processing unit receives and stores real-time detection data, establishes a concentrated brine parameter database, matches a high-salt conductivity temperature compensation coefficient using the temperature compensation module to complete the temperature correction of conductivity, uses the salt conductivity function fitting module to perform power function fitting on the normal operating data using the least squares method to establish and update the salt conductivity function model, and uses the salt conductivity coefficient calculation module to calculate the real-time salt conductivity coefficient based on the real-time detection data and update the calculation results in real-time.

[0052] The early warning judgment unit, connected to the data processing unit, is used to analyze and judge the real-time salt conductivity coefficient transmitted by the data processing unit to determine the scaling status of the concentration tower. The early warning judgment unit has a built-in scaling status judgment standard library, which stores the salt conductivity coefficient threshold for normal operation, the initial scaling judgment standard, and the severe scaling judgment standard. It is used to compare the real-time salt conductivity coefficient with the judgment standard in real time, automatically determine the operating status of the concentration tower as normal, initial scaling, or severe scaling, and transmit the scaling status signal to the execution unit.

[0053] An execution unit, connected to the early warning judgment unit, is used to receive the scaling status signal transmitted by the early warning judgment unit and issue corresponding graded early warnings. The execution unit includes a first-level early warning module and a second-level early warning module. Both modules are equipped with an audible and visual alarm, an SMS sending module, and a system background prompt module. Specifically: the first-level early warning module triggers a first-level early warning upon receiving an initial scaling signal, the audible and visual alarm emits a yellow audible and visual alarm, the SMS sending module sends an initial scaling warning SMS to maintenance personnel, and the system background prompt module displays a yellow warning pop-up window in the power plant's environmental protection maintenance backend. The second-level early warning module triggers a second-level early warning upon receiving a severe scaling signal, the audible and visual alarm emits a red audible and visual alarm, the SMS sending module sends a severe scaling warning SMS to maintenance personnel and the power plant's environmental protection manager, and the system background prompt module simultaneously displays a red warning pop-up window in both the power plant's environmental protection maintenance backend and the central control backend. The warning signal continues until manual confirmation and then disappears.

[0054] A fourth aspect of the present invention provides an electronic device including a processor and a memory, the memory storing a plurality of instructions, the processor being configured to read the instructions and execute the method as described in the first aspect.

[0055] A fifth aspect of the present invention provides a computer-readable storage medium storing a plurality of instructions which can be read by a processor and executed as described in the first aspect.

[0056] The beneficial effects of the method and system of the present invention are as follows:

[0057] 1. This invention establishes for the first time the correlation between the salt conductivity function of concentrated brine in the flue gas thickening tower of thermal power plants and the scaling state. Starting from the intrinsic mechanism of total salt content and conductivity, it accurately identifies the occurrence of CaSO4 precipitation crystallization, breaking through the limitations of single-parameter monitoring and passive monitoring in existing technologies. It realizes early warning of scaling, and when the salt conductivity coefficient shows a downward trend, the risk of scaling can be predicted, providing a sufficient time window for scaling prevention and control, and effectively avoiding equipment failure caused by scaling accumulation.

[0058] 2. This invention establishes standardized data collection specifications for total salt content and conductivity of concentrated brine, and specifically sets a 45℃ conductivity measurement benchmark and a high-salt conductivity temperature compensation system. This eliminates detection errors caused by the complex composition of high-salt wastewater and deviations in temperature compensation coefficients, ensuring the accuracy and standardization of total salt content and conductivity detection data. It provides a reliable data foundation for the establishment of the salt conductivity function and scaling judgment, with an early warning accuracy rate of over 95%.

[0059] 3. This invention classifies the operating status of the concentration tower into three levels—normal, initial scaling, and severe scaling—by using the salt conductivity coefficient threshold and scaling status grading standard. It also provides corresponding graded early warning and response measures, achieving refined and scientific control of scaling risks. In the initial scaling stage, reducing the concentration ratio can slow down the scaling process and avoid unnecessary downtime. In the case of severe scaling, timely shutdown and cleaning can prevent permanent damage to the equipment and significantly reduce the number of system downtime repairs.

[0060] 4. The scaling early warning method of the present invention is adapted to the actual operating conditions of flue gas thickening towers in thermal power plants. The test verification covers multiple thermal power plant systems. The salt derivative function model and scaling judgment criteria are universal and practical. There is no need to carry out large-scale modification of existing thickening tower equipment. Only simple sampling, detection and data processing equipment is required to realize the application. The modification cost is low and it is easy to promote in the thermal power plant industry.

[0061] 5. The scaling early warning system of the present invention realizes full automation of the process of water sample collection, parameter detection, data processing, scaling judgment and graded early warning, without the need for real-time manual supervision, thus reducing the workload of operation and maintenance personnel; the modular design of each unit of the system has a simple structure and low failure rate, and the detection data and scaling status can be stored and queried in real time, which facilitates the power plant to trace and analyze the operating status of the thickening tower and optimize operating parameters. Attached Figure Description

[0062] To more clearly illustrate the technical solutions in the specific embodiments or related technologies of the present invention, the drawings used in the description of the specific embodiments or related technologies will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0063] Figure 1 This is a flowchart of a scaling early warning method based on the salt derivative function of a flue gas thickener in a thermal power plant, provided according to an embodiment of the present invention.

[0064] Figure 2 To obtain a data set after performing salt conductivity function analysis on concentrated brine from a power plant according to an embodiment of the present invention, and to plot the fitting relationship between total salt content and conductivity in high-salt wastewater;

[0065] Figure 3 This is a schematic diagram of the curve showing the rapid decrease of the K value in the initial stage of scaling in a flue gas concentrator during the scaling process provided in an embodiment of the present invention.

[0066] Figure 4 This is a schematic diagram of a curve showing a relatively stable K value in the flue gas concentration tower after scaling, provided by an embodiment of the present invention, during the scaling process of the flue gas concentration tower.

[0067] Figure 5 This is a schematic diagram of the scaling early warning system based on the salt derivative function of the flue gas thickening tower in a thermal power plant, according to an embodiment of the present invention.

[0068] Figure 6 This is a structural diagram of an electronic device provided according to an embodiment of the present invention. Detailed Implementation

[0069] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0070] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0071] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0072] like Figure 1 As shown, the first aspect of the present invention is to provide a scaling early warning method based on the salt derivative function of a flue gas thickener in a thermal power plant, comprising:

[0073] S1. Establish standardized sampling specifications for total salt content and conductivity of concentrated brine;

[0074] In this embodiment, S1 includes:

[0075] S11. The measurement of total salinity in concentrated brine shall be strictly performed in accordance with the measurement method of "Determination of Total Salinity in Water - Gravimetric Method" (HJ / T51-1999). The sampling volume shall be determined according to the actual range of total salinity of the water sample and standardized dilution shall be performed. Specifically: when the total salinity of the water sample is in the range of 20000 mg to 50000 mg / L, accurately take 50.00 ml of water sample, dilute it to 100.00 ml, and then measure the total salinity; when the total salinity of the water sample is ≥50000 mg / L, accurately take 10.00 ml of water sample, dilute it to 100.00 ml, and then measure the total salinity. All water samples shall be measured in parallel. If the relative error of the parallel sample measurement results is >0.5%, it is determined that there is an error in the sampling or detection, and resampling and measurement are required.

[0076] S12, the conductivity measurement abandons the traditional method of measuring conductivity at 25℃ with compensation, and directly measures the actual conductivity of high-salinity wastewater samples at 45℃. This measurement benchmark is set based on the following actual operating conditions: high-salinity wastewater has a high salt content and complex composition, and deviates from the temperature compensation coefficients of all existing conductivity meters. If the temperature-compensated conductivity at 25℃ is used, it will lead to a large error in the actual conductivity value; the temperature of high-salinity wastewater in the flue gas concentration tower of thermal power plants is affected by the combined effects of flue gas temperature, ambient temperature, and concentration ratio, and is basically stable between 45℃±5℃; at the same time, concentrated brine samples are collected using 1L glass bottles or polyethylene plastic bottles, and the transportation distance is usually 400-1500m. Including sampling and pretreatment time, the water sample temperature drops by about 2-5℃ in winter and about 1-4℃ in summer. Considering the above factors, the conductivity measurement benchmark temperature is set at 45℃, which can essentially eliminate the difference in temperature compensation coefficients for high-salinity wastewater with different compositions, ensuring the accuracy of conductivity detection data.

[0077] S2, Construct a high-salt conductivity temperature compensation system;

[0078] Because high-salinity wastewater has a high salt content and complex salt composition, conventional temperature compensation coefficients cannot meet its conductivity detection requirements. Therefore, this invention specifically constructs a high-salinity conductivity temperature compensation system, wherein S2 includes:

[0079] S21. High-salt water samples with a total salt content in the range of 80,000 mg / L to 250,000 mg / L were selected as test water samples. This range is the typical total salt content range of concentrated brine in flue gas thickening towers of thermal power plants, and the test results have practical application value.

[0080] S22, Conduct temperature compensation coefficient determination of 6 sets of parallel data. The determination process is as follows: First, the initial conductivity of the test water sample at 25℃ is measured. Then, the water sample is heated to a predetermined temperature in the range of 40℃-48℃. Then, the water sample is allowed to cool naturally to the predetermined temperature. The actual conductivity of the water sample at the predetermined temperature is measured. By calculating the initial conductivity and the actual conductivity, the conductivity temperature compensation coefficient at the corresponding temperature is obtained.

[0081] S23, the standardized temperature compensation coefficients corresponding to each temperature in the range of 40℃-48℃ are summarized, and the specific values ​​are: 0.0188 for 48℃ and 47℃, 0.0190 for 46℃, 0.0191 for 45℃, 0.0192 for 44℃, 0.0193 for 43℃, 0.0194 for 42℃, and 0.0195 for 41℃ and 40℃;

[0082] S24, Set temperature adjustment requirements: If the actual temperature of the collected concentrated saline sample exceeds the range of 40℃-48℃, the water sample temperature must be adjusted to the specified temperature range by stirring and heating or cooling before the conductivity measurement is performed to ensure the matching of the test data with the temperature compensation coefficient.

[0083] S3, Establish the salt derivative function model under normal operating conditions;

[0084] In a preferred embodiment, S3 includes:

[0085] S31. Data collection includes: collecting data on the total salt content and conductivity at 45°C of concentrated brine under normal operating conditions (no precipitation crystallization, no scaling) of the flue gas concentration tower in thermal power plants. Data collection should cover different operating periods and different concentration ratios to ensure the comprehensiveness and representativeness of the data.

[0086] S32, Model fitting is performed, including: using the least squares method to fit the collected total salt content and conductivity data to obtain the power function relationship between total salt content and conductivity under normal operating conditions. This power function is the salt conductivity function of the concentration tower under normal operating conditions.

[0087] S33. Model validation was conducted, including testing and validation in the flue gas enrichment tower systems of three or more different thermal power plants. The results showed that the total salt content and conductivity of each system exhibited a stable power function relationship, and the goodness of fit (R²) of the power function formula to the original data was between 93.14% and 95.8%. Residual analysis of the fitting results showed that the residuals (the difference between the actual measured value and the fitted value of the trend line) were randomly and irregularly distributed around the trend line, indicating that the power function model can accurately reflect the intrinsic relationship between total salt content and conductivity under normal operating conditions.

[0088] S34, Determine the salt conductivity threshold, including: Calculate the salt conductivity K based on the fitted data. Under normal operating conditions, the salt conductivity K values ​​of each test system are all >2200. Therefore, K>2200 is set as the salt conductivity threshold for normal operation of the concentration tower. The calculation formula for the salt conductivity K is shown in the following formula (1):

[0089] (1);

[0090] S4, real-time monitoring of the total salt content and standard conductivity of the concentrated brine in the concentration tower;

[0091] In a preferred embodiment, S4 includes:

[0092] S41, in accordance with the standardized collection specifications established in S1, the concentrated brine in the concentration tower is sampled in real time. The total salt content detection strictly follows the requirements of sampling, dilution, and parallel sample determination. The conductivity detection first determines whether the actual temperature of the water sample is within the range of 40℃-48℃. If it exceeds this range, it is adjusted to this range by a temperature regulating device.

[0093] S42, combined with the high-salt conductivity temperature compensation system constructed by S2, selects the corresponding temperature compensation coefficient according to the actual temperature of the water sample, performs temperature correction on the measured conductivity, and obtains the standard conductivity at 45℃, ensuring the standardization and accuracy of the monitoring data.

[0094] S5, determine the scaling state based on the change in salt conductivity coefficient;

[0095] In a preferred embodiment, S5 includes:

[0096] S51, Calculate the real-time salt conductivity coefficient, including: based on the total salt content monitored in real time in S4 and the standard conductivity at 45°C, obtain the real-time salt conductivity coefficient during the operation of the concentration tower according to the same calculation method as in S3;

[0097] like Figures 3-4 As shown, S52, determining the scaling state judgment criteria and determining the scaling state judgment result based on the scaling state judgment criteria includes:

[0098] In the early stage of scaling, if the real-time salt conductivity coefficient drops from the normal threshold of >2200 to below 2000 and shows a rapid decreasing trend in a short period of time, it is determined that the concentration tower has entered the early stage of scaling. At this time, CaSO4 precipitation crystals begin to appear in the concentration tower, and the power function relationship between total salt content and conductivity begins to fail. In the case of severe scaling, if the real-time salt conductivity coefficient continues to decrease and eventually stabilizes between 800-1000, it is determined that the concentration tower has undergone severe scaling. At this time, the power function relationship between total salt content and conductivity completely fails and instead shows obvious linear function characteristics. Moreover, the higher the concentration ratio, the lower the salt conductivity coefficient.

[0099] The underlying mechanism for judging the scaling state is as follows: the most abundant cations in concentrated brine are Na+, Ca2+, and Mg2+, with equivalent masses of 23 g / mol, 20 g / mol, and 12 g / mol, respectively, and the anion is SO42-. 2- and Cl - The equivalent masses were 48 g / mol and 35.5 g / mol, respectively, and the main precipitate in the concentration tower was CaSO4, which was the substance with the largest equivalent mass among all ion combinations. When CaSO4 precipitation and crystallization occurred in the concentration tower, Ca... 2+ and SO4 2- It precipitates out of the solution as a precipitate, causing a decrease in the total salt content in the concentrated brine, while the remaining Na in the solution... + Mg 2+ and Cl - The relative changes in the proportion of readily soluble ions disrupt the original correlation between total salt content and conductivity, resulting in a decrease in the salt conductivity coefficient. Furthermore, the more severe the precipitation crystallization, the lower the salt conductivity coefficient.

[0100] S6, classify and issue early warnings based on the scaling status, including: classifying and issuing early warnings on the scaling risk of the concentration tower based on the scaling status judgment results described in S5, and providing corresponding countermeasures to achieve precise control of scaling.

[0101] In a preferred embodiment, the graded early warning system for scaling risk in the concentration tower includes:

[0102] When it is determined to be the initial stage of scaling, a Level 1 warning is issued. The warning methods include on-site audible and visual alarms, SMS reminders from maintenance personnel, and pop-up notifications in the system background. The response measures for the Level 1 warning are: immediately reduce the concentration ratio of the concentration tower, reduce the concentration rate of high-salt wastewater, inhibit the formation of CaSO4 supersaturated solution, and delay the process of precipitating crystallization.

[0103] When severe scaling is detected, a Level II warning is issued. The warning method is based on the Level I warning, with the addition of a central control alarm from the power plant's environmental protection operation and maintenance center. The response measures for the Level II warning are as follows: immediately stop the operation of the thickening tower, and organize operation and maintenance personnel to carry out a comprehensive cleaning of the thickening tower's circulating pump outlet, spray pipes and nozzles, agitation pump, tower walls, and tower bottom to prevent further scaling and permanent damage to the equipment.

[0104] like Figure 5 As shown, a second aspect of this embodiment also provides a scaling early warning system based on the salt derivative function of a flue gas thickening tower in a thermal power plant, comprising:

[0105] Standardized data acquisition module 101 is used to develop standardized data acquisition specifications for total salt content and conductivity of concentrated brine.

[0106] High-salt conductivity temperature compensation system construction module 102 is used to construct a high-salt conductivity temperature compensation system;

[0107] Salt derivative function model establishment module 103 is used to establish a salt derivative function model under normal operating conditions;

[0108] The total salt content and standard conductivity monitoring module 104 is used to monitor the total salt content and standard conductivity of the concentrated brine in the concentration tower in real time.

[0109] The scaling condition judgment module 105 is used to judge the scaling condition based on the change in salt conductivity coefficient.

[0110] The graded early warning module 106 is used to provide graded early warnings based on the scaling status, including: providing graded early warnings on the scaling risk of the concentration tower based on the judgment result of the scaling status, and providing corresponding countermeasures to achieve precise control of scaling.

[0111] A third aspect of this embodiment also provides a scaling early warning device based on the salt derivative function of a flue gas concentration tower in a thermal power plant, comprising:

[0112] The water sampling unit, used according to the standardized sampling specifications in step S1, performs real-time sampling and pretreatment of concentrated brine in the flue gas concentration tower of a thermal power plant, and is the basic unit of the entire system. The water sampling unit is equipped with sampling bottles, a dilution device, a temperature control device, and sampling pipelines. The sampling bottles are 1L glass bottles or polyethylene plastic bottles to meet the requirements for water sample collection and transportation. The dilution device is a high-precision quantitative diluent, capable of accurate sampling of 50.00ml, 10.00ml, and volumetric dilution to 100.00ml. The temperature control device includes a stirrer, a heating module, and a cooling module, capable of precisely adjusting the temperature of the concentrated brine sample to the specified range of 40℃-48℃. The sampling pipelines are made of anti-scaling material to prevent scale buildup from affecting the accuracy of water sample collection.

[0113] The detection and analysis unit, connected to the water sample collection unit, is used for the accurate detection of total salinity and conductivity of the pretreated concentrated saline sample. It is the core detection unit of the device. The detection and analysis unit includes a gravimetric total salinity analyzer and a conductivity analyzer. The gravimetric total salinity analyzer is designed strictly according to the detection standard of "Determination of Total Salinity in Water by Gravimetric Method" (HJ / T51-1999). It supports automatic sampling, automatic drying, and automatic weighing, and can realize the synchronous measurement of parallel samples. It automatically calculates the relative error of parallel samples. When the relative error is >0.5%, the instrument will automatically issue a prompt signal for resampling. The conductivity analyzer is a high-precision portable conductivity analyzer that can measure the conductivity of concentrated saline samples at different temperatures. The instrument has a built-in temperature sensor that can detect the actual temperature of the water sample in real time. It is linked with the temperature compensation coefficient table of the data processing unit to automatically select the compensation coefficient corresponding to the temperature and perform temperature correction on the measured conductivity to obtain the standard conductivity at 45℃.

[0114] The data processing unit, connected to the detection and analysis unit, receives the total salt content and conductivity detection data transmitted by the detection and analysis unit, performs data processing, model fitting, and salt conductivity coefficient calculation, and is the core computing unit of the device. The data processing unit is an industrial-grade computer with built-in data processing software, a salt conductivity function fitting module, a temperature compensation module, and a salt conductivity coefficient calculation module. The data processing unit receives and stores real-time detection data, establishes a concentrated brine parameter database, matches the high-salt conductivity temperature compensation coefficient through the temperature compensation module to complete the temperature correction of conductivity, uses the salt conductivity function fitting module to perform power function fitting on the normal operation data using the least squares method to establish and update the salt conductivity function model, and calculates the real-time salt conductivity coefficient based on the real-time detection data through the salt conductivity coefficient calculation module, updating the calculation results in real-time.

[0115] The early warning judgment unit, connected to the data processing unit, is used to analyze and judge the real-time salt conductivity coefficient transmitted by the data processing unit to determine the scaling state of the concentration tower. It is the core judgment unit of the device. The early warning judgment unit has a built-in scaling state judgment standard library, which stores the salt conductivity coefficient threshold for normal operation (K>2200), the initial scaling judgment standard (K drops below 2000 and decreases rapidly), and the severe scaling judgment standard (K is stable between 800-1000). It can compare the real-time salt conductivity coefficient with the judgment standard in real time, automatically determine the operating state of the concentration tower (normal, initial scaling, severe scaling), and transmit the scaling state signal to the execution unit.

[0116] The execution unit, connected to the early warning judgment unit, receives the scaling status signal transmitted by the early warning judgment unit and issues corresponding graded early warnings; it is the output unit of the device. This unit includes a primary early warning module and a secondary early warning module. Both modules are equipped with an audible and visual alarm, an SMS sending module, and a system background prompt module. Specifically: the primary early warning module triggers a primary early warning upon receiving an initial scaling signal; the audible and visual alarm emits a yellow audible and visual alarm, the SMS sending module sends an initial scaling warning SMS to maintenance personnel, and the system background prompt module displays a yellow warning pop-up in the power plant's environmental protection maintenance backend. The secondary early warning module triggers a secondary early warning upon receiving a severe scaling signal; the audible and visual alarm emits a red audible and visual alarm, the SMS sending module sends a severe scaling warning SMS to maintenance personnel and the power plant's environmental protection manager, and the system background prompt module simultaneously displays a red warning pop-up in both the power plant's environmental protection maintenance backend and the central control backend. The warning signal persists until manual confirmation and is then cleared.

[0117] The present invention also provides a memory that stores multiple instructions for implementing the method as described in Embodiment 1.

[0118] like Figure 6 As shown, the present invention also provides an electronic device, including a processor 301 and a memory 302 connected to the processor 301. The memory 302 stores a plurality of instructions, which can be loaded and executed by the processor to enable the processor to perform the method as described in Embodiment 1.

[0119] Application Examples

[0120] The scaling early warning method and system based on the salt conductivity function of the flue gas thickener in thermal power plants of the present invention have been tested and applied in multiple thermal power plants, including Unit 1 of Laicheng Power Plant and the flue gas thickener system of L Plant. The following are two typical specific embodiments to illustrate the implementation process and application effect of the present invention in detail. Embodiment 1 is the establishment and verification of the salt conductivity function model under normal operating conditions, and Embodiment 2 is the application of early warning and prevention under scaling conditions.

[0121] Application Example 1: Establishment and Verification of the Salt Derivative Function Model under Normal Operating Conditions

[0122] Implementation target: Flue gas thickening tower system of 300MW unit in Plant L. The system adopts the process flow of bypass flue gas thickening tower + main flue gas evaporation and drying. The desulfurization wastewater to be treated is a CaSO4 saturated solution. Under normal operation, the concentration ratio is 5-8 times, and the total salt content of concentrated brine is in the range of 80000mg / L~200000mg / L.

[0123] Implementation process:

[0124] 1. Water Sample Collection and Pretreatment: Following the standardized collection procedures in step S1 of this invention, concentrated brine under normal operating conditions of the concentration tower was sampled continuously for three months, once a day, for a total of 90 valid water samples. 1L polyethylene plastic bottles were used for sampling, with a transport distance of 800m. The sampling and pretreatment time was approximately 30 minutes. The water sample temperature decreased by approximately 2℃ in summer and approximately 3℃ in winter, with the actual water sample temperature remaining within the range of 40℃-48℃.

[0125] Total salinity testing: Based on the total salinity range of the water samples, 10.00 ml of water sample was diluted to 100.00 ml and tested using a gravimetric total salinity analyzer. Two parallel samples were measured for each group of water samples, and the relative error was calculated. The relative error of the parallel samples of all water samples was between 0.2% and 0.4%, which meets the requirement of ≤0.5%.

[0126] Conductivity detection: The conductivity of the water sample at the actual temperature is measured using a high-precision conductivity meter. The temperature compensation coefficients of step S2 of this invention (0.0191 for 45℃, 0.0190 for 46℃, and 0.0188 for 47℃) are matched to the actual temperature of the water sample to correct the measured conductivity for temperature, thus obtaining the standard conductivity at 45℃.

[0127] 2. Salt derivative function model fitting

[0128] The total salt content (denoted as y, unit: mg / L) and standard conductivity at 45℃ (denoted as x, unit: mS / cm) of 90 effective water samples were imported into the data processing unit. Power function fitting was performed using the least squares method to obtain the salt conductivity function under normal operating conditions of the concentration tower: y = 473.72x 1.3033 .

[0129] The fitting results were verified, and the goodness of fit of the power function to the original data was R²=95.98%, which is higher than the minimum requirement of 93.14%. The residual analysis of the fitting results showed that the residuals were randomly distributed around the trend line between -50000mg / L and 50000mg / L, without obvious pattern, indicating that the power function model can accurately reflect the intrinsic relationship between total salt content and conductivity under normal operating conditions.

[0130] 3. Salt conductivity coefficient calculation and threshold verification

[0131] Based on the power function data obtained from the fitting, the salt conductivity coefficient k was calculated according to the calculation method of the present invention. The salt conductivity coefficient K values ​​of the 90 water samples in the system were distributed between 2250 and 2800, all of which were greater than the normal threshold of 2200, verifying the rationality of the salt conductivity coefficient threshold set by the present invention.

[0132] 4. Long-term model validation

[0133] The established salt conductivity function model was applied to monitor the normal operation of the concentration tower. The salt conductivity coefficient was calculated in real time for six consecutive months. All real-time salt conductivity coefficients were stable above 2200, and the total salt content and conductivity always maintained a power function relationship. This indicates that the salt conductivity function model has good stability and applicability and can be used as a benchmark for judging the normal operation of the concentration tower.

[0134] This embodiment successfully established a salt conductivity function model under normal operating conditions for the flue gas thickener system of the 300MW unit at Plant L. The model exhibits high goodness of fit and good stability, providing a reliable judgment benchmark for subsequent scaling early warning. Standardized data acquisition and testing procedures ensured data accuracy; the relative errors of all parallel samples met requirements, and the conductivity data after temperature correction accurately reflected the actual conductivity characteristics of the concentrated brine.

[0135] Application Example 2: Early Warning and Prevention in Scaling Conditions

[0136] Implementation target: The flue gas thickening tower system of Unit 1 of Laicheng Power Plant. The system adopts the bypass flue gas thickening tower + bypass flue gas evaporation and drying process. The initial total salt content of the desulfurization wastewater to be treated is 30,000 mg / L. The normal operating concentration ratio is 6-9 times. Due to the excessively high concentration ratio in the early stage, CaSO4 precipitation crystallization and scaling trend appeared.

[0137] Implementation process

[0138] 1. Real-time monitoring and data processing

[0139] The scaling early warning system of this invention is used to monitor the concentration tower in real time. The sampling frequency is once every 2 hours. Water samples are collected and pretreated according to the collection specifications in step S1. For total salt content detection, 10.00 ml of water sample is diluted to 100.00 ml, and the relative error of parallel samples is controlled within 0.5%. For conductivity detection, the water sample temperature is adjusted to 45°C by a temperature adjustment device, and the standard conductivity at 45°C is directly measured without additional temperature correction.

[0140] The total salt content and conductivity data detected in real time are transmitted to the data processing unit, the salt conductivity coefficient K is calculated in real time, and the calculation result is transmitted to the early warning judgment unit.

[0141] 2. Early warning and response to initial scaling

[0142] By the 5th day of monitoring, the early warning judgment unit found that the real-time salt conductivity coefficient of the concentration tower dropped rapidly from 2500 to 1950, which is below the initial scaling threshold of 2000, and continued to drop to 1800 within 8 hours. According to the scaling status judgment standard of the present invention, the concentration tower was determined to have entered the initial scaling stage. The early warning judgment unit immediately sent an initial scaling signal to the execution unit, and the execution unit triggered a first-level early warning: the on-site audible and visual alarm issued a yellow audible and visual alarm, sent a warning text message to the operation and maintenance personnel, and a yellow warning pop-up window appeared in the power plant's environmental protection operation and maintenance background.

[0143] Upon receiving the Level 1 warning, the maintenance personnel immediately took countermeasures: reducing the concentration ratio of the concentration tower from 9 times to 5 times to decrease the concentration rate of high-salt wastewater, and at the same time appropriately increasing the spray flow rate to alleviate the formation of CaSO4 supersaturated solution.

[0144] 3. Monitoring the effectiveness of early warning

[0145] After taking countermeasures, the concentration tower was monitored in real time. It was found that the downward trend of the salt conductivity coefficient was significantly suppressed, slowly rising from 1800 to 2100 and stabilizing between 2100 and 2200. This indicates that the control measures in the early stage of scaling were effective, the process of CaSO4 precipitation and crystallization was slowed down, and no obvious scaling accumulation was found in the concentration tower. There was no need to shut down the tower for cleaning.

[0146] 4. Simulation, early warning, and prevention of severe scaling

[0147] To verify the early warning effect of this invention on severe scaling, a scaling simulation test was conducted on the concentration tower: the concentration ratio was artificially increased to 12 times and operated continuously for 24 hours. Monitoring showed that the salt conductivity coefficient dropped rapidly from 2100 to 950 and stabilized between 900 and 950, which met the severe scaling threshold of 800-1000. Moreover, the power function relationship between total salt content and conductivity failed and instead showed a linear function relationship. The early warning judgment unit determined it to be severe scaling, and the execution unit triggered a secondary early warning: the on-site audible and visual alarm issued a red audible and visual alarm, sent a warning text message to the operation and maintenance personnel and the power plant's environmental protection manager, and the power plant's environmental protection operation and maintenance backend and the central control backend simultaneously displayed a red warning pop-up window.

[0148] The test was immediately stopped, and the maintenance personnel shut down the thickener for inspection. They found a small amount of CaSO4 crystal scale deposits at the outlet of the circulating pump and the interface of the spray pipe, which was an early stage of severe scaling. The scaled areas were then cleaned with high-pressure water jet. After cleaning, the concentration ratio was restored to 6 times, and the thickener returned to normal operation without causing equipment failure or economic loss.

[0149] This embodiment successfully implemented graded early warning for initial and severe scaling in the flue gas thickener system of Unit 1 at Laicheng Power Plant. The first-level warning promptly suppressed the scaling trend, preventing scale buildup. The second-level warning accurately identified severe scaling, providing a basis for timely shutdown and cleaning, thus preventing equipment failure. Experiments show that the scaling early warning method of this invention can accurately determine the scaling status, with an accuracy rate of 98%. The graded prevention and control measures can effectively delay or eliminate scaling risks, significantly reducing the number of system shutdowns for emergency repairs and lowering operation and maintenance costs. After applying the early warning system of this invention, the thickener did not experience any downtime due to scaling for six consecutive months, demonstrating significantly improved operational stability.

[0150] The scaling early warning method and system based on the salt conductivity function of flue gas thickeners in thermal power plants of the present invention are not limited to the implementation objects and parameters of the above two embodiments. Appropriate parameter adjustments and model optimizations can be made according to the actual operating conditions of different thermal power plant flue gas thickeners, such as process flow, treated water volume, and wastewater composition. These adjustments include:

[0151] 1. Sampling frequency adjustment: For thickening tower systems with large water volume, high concentration ratio, and high risk of scaling, the sampling frequency can be appropriately increased (e.g., once every 1 hour); for thickening tower systems with small water volume and stable operation, the sampling frequency can be appropriately reduced (e.g., twice a day) to ensure that the changing trend of the salt conductivity coefficient can be captured in real time.

[0152] 2. Salt derivative function model optimization: For high-salt wastewater with different compositions (such as Mg...) 2+ For desulfurization wastewater with high content of certain components, based on this invention, ion component detection data can be added to optimize the salt derivative function model, further improving the model's fit and early warning accuracy.

[0153] 3. Temperature compensation coefficient extension: If the temperature of the concentrated brine in the flue gas concentration tower of a thermal power plant exceeds the range of 40℃-48℃, the temperature compensation coefficient in other temperature ranges can be determined according to the temperature compensation coefficient determination method of this invention, thereby extending the applicable range of the temperature compensation system.

[0154] 4. Expanded Early Warning Methods: The execution unit of this invention can add early warning methods according to the actual needs of the power plant, such as on-site large screen display, power plant internal communication software reminders, etc., to ensure that operation and maintenance personnel can receive early warning signals in a timely manner.

[0155] 5. System Automation Upgrade: The scaling early warning system of this invention can be linked with the DCS distributed control system of thermal power plants to realize the automatic linkage between early warning signals and the operating parameters of the thickening tower, such as automatically reducing the concentration ratio and closing the feed valve in the early stage of scaling, thereby further improving the automation level of the system and reducing manual intervention.

[0156] The scaling early warning method and system based on the salt conductivity function of flue gas thickeners in thermal power plants of this invention have significant industrial applicability. They are applicable to various types of flue gas thickeners in thermal power plants employing flue gas thickening and drying processes, including thickener systems with different unit capacities such as 300MW, 600MW, and 1000MW, as well as thickener systems with different process flows such as bypass flue gas thickener + main flue gas evaporation and drying, and bypass flue gas thickener + bypass flue gas evaporation and drying. The method of this invention does not require large-scale modification of existing thickener equipment; only sampling, testing, and data processing equipment are needed for application, resulting in low modification costs and short construction periods. The system of this invention features a modular design, making installation, commissioning, and maintenance convenient, with a low failure rate. It can adapt to the high-temperature, high-dust industrial environment of thermal power plants and exhibits good operational stability. The application of this invention can effectively solve the problem of scaling early warning in flue gas concentration towers of thermal power plants, realize early identification and graded prevention and control of scaling, significantly reduce the number of system shutdowns and emergency repairs caused by scaling, reduce equipment and labor maintenance costs, improve the continuous and stable operation capability of the zero-discharge system for high-salt wastewater in thermal power plants, meet the requirements of national ecological civilization construction and environmental protection compliance of thermal power plants, and has broad prospects for industrial promotion and significant economic and environmental benefits.

[0157] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A scaling early warning method based on the salt derivative function of a flue gas thickening tower in a thermal power plant, characterized in that, include: S1. Establish standardized sampling specifications for total salt content and conductivity of concentrated brine; S2, Construct a high-salt conductivity temperature compensation system; S3, Establish the salt derivative function model under normal operating conditions; S4, real-time monitoring of the total salt content and standard conductivity of the concentrated brine in the concentration tower; S5, determine the scaling state based on the change in salt conductivity coefficient; S6, classify and issue early warnings based on the scaling status, including: classifying and issuing early warnings on the scaling risk of the concentration tower based on the judgment result of the scaling status, and providing corresponding countermeasures to achieve precise control of scaling.

2. The scaling early warning method based on the salt derivative function of a flue gas thickening tower in a thermal power plant according to claim 1, characterized in that, S1 includes: S11. The total salinity of concentrated brine is measured according to the measurement method of "Determination of Total Salinity in Water - Gravimetric Method" (HJ / T51-1999). The sampling volume is determined based on the actual total salinity range of the water sample, and standardized dilution is performed. When the total salinity of the water sample is in the range of 20000 mg to 50000 mg / L, an accurate 50.00 ml sample is taken, diluted to 100.00 ml, and then the total salinity is measured. When the total salinity of the water sample is ≥50000 mg / L, an accurate 10.00 ml sample is taken, diluted to 100.00 ml, and then the total salinity is measured. All water samples are measured in parallel. If the relative error of the parallel sample measurement results is >0.5%, it is determined that there is an error in the sampling or detection, and resampling and measurement are required. S12, conductivity measurement includes: direct measurement of the actual conductivity of high saline sample at 45℃.

3. The scaling early warning method based on the salt derivative function of a flue gas thickening tower in a thermal power plant according to claim 2, characterized in that, S2 includes: S21. High-salinity water samples with a total salt content in the range of 80,000 mg / L to 250,000 mg / L were selected as test water samples. S22, the temperature compensation coefficient of 6 sets of parallel data was determined. The determination process was as follows: first, the initial conductivity of the test water sample at 25℃ was measured, then the water sample was heated to a predetermined temperature in the range of 40℃-48℃, and then the water sample was allowed to cool naturally to the predetermined temperature. The actual conductivity of the water sample at the predetermined temperature was measured. The conductivity temperature compensation coefficient at the corresponding temperature was obtained by calculating the initial conductivity and the actual conductivity. S23, obtains the standardized temperature compensation coefficients for each temperature in the range of 40℃-48℃; S24, Set temperature adjustment requirements: If the actual temperature of the collected concentrated saline sample exceeds the range of 40℃-48℃, adjust the water sample temperature to the specified temperature range by stirring and heating or cooling before conducting conductivity measurement to ensure the matching of the test data with the temperature compensation coefficient.

4. The scaling early warning method based on the salt derivative function of a flue gas thickening tower in a thermal power plant according to claim 3, characterized in that, The specific values ​​of the standardized temperature compensation coefficients corresponding to each temperature within the range of 40℃-48℃ in S23 are as follows: 0.0188 for 48℃ and 47℃, 0.0190 for 46℃, 0.0191 for 45℃, 0.0192 for 44℃, 0.0193 for 43℃, 0.0194 for 42℃, and 0.0195 for 41℃ and 40℃.

5. A scaling early warning method based on the salt derivative function of a flue gas thickening tower in a thermal power plant according to claim 4, characterized in that, S3 includes: S31, collect data, including: collect data on the total salt content and conductivity of concentrated brine at 45℃ under normal operating conditions of flue gas concentration towers in thermal power plants, without precipitation crystals or scaling. Data collection needs to cover different operating periods and different concentration ratios. S32, Model fitting is performed, including: using the least squares method to fit the collected total salt content and conductivity data to obtain the power function relationship between total salt content and conductivity under normal operating conditions. This power function is the salt conductivity function of the concentration tower under normal operating conditions. S33, Model validation, including: conducting tests and validations in the flue gas enrichment tower systems of three or more different thermal power plants, ensuring that the total salt content and conductivity of each system exhibit a stable power function relationship, and that the goodness of fit R² of the power function formula to the original data is between 93.14% and 95.8%; and performing residual analysis on the fitting results. S34, Determine the salt conductivity threshold, including: calculating the salt conductivity K based on the fitted data; under normal operating conditions, setting the salt conductivity K > 2200 as the salt conductivity threshold for normal operation of the concentration tower; the calculation formula for the salt conductivity K is shown in the following formula (1): （1）。 6. A scaling early warning method based on the salt derivative function of a flue gas thickening tower in a thermal power plant, as described in claim 5, is characterized in that... S4 includes: S41, in accordance with the standardized collection specifications established in S1, the concentrated brine in the concentration tower is sampled in real time. The total salt content detection strictly follows the requirements of sampling, dilution, and parallel sample determination. The conductivity detection first determines whether the actual temperature of the water sample is within the range of 40℃-48℃. If it exceeds this range, it is adjusted to this range by a temperature regulating device. S42, combined with the high-salt conductivity temperature compensation system constructed by S2, selects the corresponding temperature compensation coefficient according to the actual temperature of the water sample, and performs temperature correction on the measured conductivity to obtain the standard conductivity at 45℃.

7. A scaling early warning method based on the salt derivative function of a flue gas thickening tower in a thermal power plant according to claim 6, characterized in that, S5 includes: S51, Calculate the real-time salt conductivity coefficient, including: based on the total salt content monitored in real time in S4 and the standard conductivity at 45°C, obtain the real-time salt conductivity coefficient during the operation of the concentration tower according to the same calculation method as in S3; S52, determine the scaling state judgment criteria and determine the scaling state judgment result based on the scaling state judgment criteria, wherein the scaling state judgment criteria include: In the early stage of scaling, if the real-time salt conductivity coefficient drops from the normal threshold of K > 2200 to below 2000 and shows a rapid decreasing trend in a short period of time, it is determined that the concentration tower has entered the early stage of scaling. At this time, CaSO4 begins to precipitate and crystallize in the concentration tower, and the power function relationship between total salt content and conductivity begins to fail. In the case of severe scaling, if the real-time salt conductivity coefficient K continues to decrease and eventually stabilizes between 800-1000, it is determined that severe scaling has occurred in the concentration tower. At this time, the power function relationship between total salt content and conductivity completely fails and instead shows obvious linear function characteristics. Moreover, the higher the concentration ratio, the lower the salt conductivity coefficient.

8. A scaling early warning method based on the salt derivative function of a flue gas thickening tower in a thermal power plant according to claim 7, characterized in that, The classification and early warning system for scaling risk in the concentration tower includes: When it is determined to be the initial stage of scaling, a Level 1 warning is issued. The warning methods include on-site audible and visual alarms, SMS reminders from maintenance personnel, and pop-up notifications in the system background. The response measures for the Level 1 warning are: immediately reduce the concentration ratio of the concentration tower, reduce the concentration rate of high-salt wastewater, inhibit the formation of CaSO4 supersaturated solution, and delay the process of precipitating crystallization. When severe scaling is detected, a Level II warning is issued. The warning method is based on the Level I warning, with the addition of a central control alarm from the power plant's environmental protection operation and maintenance center. The response measures for the Level II warning are: immediately stop the operation of the thickening tower and carry out a comprehensive scaling cleaning of the thickening tower's circulating pump outlet, spray pipes and nozzles, disturbance pump, tower walls, and tower bottom.

9. A scaling early warning system based on the salt derivative function of a flue gas thickening tower in a thermal power plant, used to implement the method described in any one of claims 1-8, characterized in that, include: The standardized data acquisition module (101) is used to develop standardized data acquisition specifications for total salt content and conductivity of concentrated brine. A high-salt conductivity temperature compensation system construction module (102) is used to construct a high-salt conductivity temperature compensation system; The salt derivative function model establishment module (103) is used to establish the salt derivative function model under normal operating conditions; A total salt content and standard conductivity monitoring module (104) is used to monitor the total salt content and standard conductivity of the concentrated brine in the concentration tower in real time. The scaling condition judgment module (105) is used to judge the scaling condition based on the change in salt conductivity coefficient; The graded early warning module (106) is used to provide graded early warning based on the scaling status, including: providing graded early warning for the scaling risk of the concentration tower based on the judgment result of the scaling status, and providing corresponding countermeasures to achieve precise control of scaling.

10. A scaling early warning device based on the salt derivative function of a flue gas thickening tower in a thermal power plant, used to implement the method described in any one of claims 1-8, characterized in that, include: The water sampling unit is used to sample and pretreat concentrated brine in the flue gas concentration tower of a thermal power plant in real time according to the standardized sampling specifications in step S1. The water sampling unit is equipped with a sampling bottle, a dilution device, a temperature control device, and sampling tubing. The sampling bottle is a 1L glass bottle or a polyethylene plastic bottle. The dilution device is a high-precision quantitative dilution instrument. The temperature control device includes a stirrer, a heating module, and a cooling module, used to precisely adjust the temperature of the concentrated brine sample to a specified range of 40℃-48℃. The sampling tubing is made of anti-scaling material. The detection and analysis unit, connected to the water sample collection unit, is used for the accurate detection of total salinity and conductivity of the pretreated concentrated saline sample. The detection and analysis unit includes a gravimetric total salinity analyzer and a conductivity analyzer. The gravimetric total salinity analyzer is designed according to the testing standard "Determination of Total Salinity in Water - Gravimetric Method" (HJ / T51-1999), supporting automatic sampling, automatic drying, and automatic weighing. It can achieve synchronous measurement of parallel samples and automatically calculate the relative error of parallel samples. When the relative error > 0.5%, the instrument automatically issues a prompt signal for resampling. The conductivity analyzer is a high-precision portable conductivity meter that measures the conductivity of concentrated saline samples at different temperatures. The instrument has a built-in temperature sensor to detect the actual temperature of the water sample in real time and is linked with the temperature compensation coefficient table of the data processing unit to automatically select the corresponding temperature compensation coefficient to correct the measured conductivity for temperature, obtaining the standard conductivity at 45℃. A data processing unit, connected to the detection and analysis unit, is used to receive total salt content and conductivity detection data transmitted by the detection and analysis unit, and to perform data processing, model fitting, and salt conductivity coefficient calculation. The data processing unit is an industrial-grade computer with built-in data processing software, a salt conductivity function fitting module, a temperature compensation module, and a salt conductivity coefficient calculation module. The data processing unit receives and stores real-time detection data, establishes a concentrated brine parameter database, matches a high-salt conductivity temperature compensation coefficient using the temperature compensation module to complete the temperature correction of conductivity, uses the salt conductivity function fitting module to perform power function fitting on the normal operating data using the least squares method to establish and update the salt conductivity function model, and uses the salt conductivity coefficient calculation module to calculate the real-time salt conductivity coefficient based on the real-time detection data and update the calculation results in real-time. The early warning judgment unit, connected to the data processing unit, is used to analyze and judge the real-time salt conductivity coefficient transmitted by the data processing unit to determine the scaling status of the concentration tower. The early warning judgment unit has a built-in scaling status judgment standard library, which stores the salt conductivity coefficient threshold for normal operation, the initial scaling judgment standard, and the severe scaling judgment standard. It is used to compare the real-time salt conductivity coefficient with the judgment standard in real time, automatically determine the operating status of the concentration tower as normal, initial scaling, or severe scaling, and transmit the scaling status signal to the execution unit. An execution unit, connected to the early warning judgment unit, is used to receive the scaling status signal transmitted by the early warning judgment unit and issue corresponding graded early warnings. The execution unit includes a first-level early warning module and a second-level early warning module. Both modules are equipped with an audible and visual alarm, an SMS sending module, and a system background prompt module. Specifically: the first-level early warning module triggers a first-level early warning upon receiving an initial scaling signal, the audible and visual alarm emits a yellow audible and visual alarm, the SMS sending module sends an initial scaling warning SMS to maintenance personnel, and the system background prompt module displays a yellow warning pop-up window in the power plant's environmental protection maintenance backend. The second-level early warning module triggers a second-level early warning upon receiving a severe scaling signal, the audible and visual alarm emits a red audible and visual alarm, the SMS sending module sends a severe scaling warning SMS to maintenance personnel and the power plant's environmental protection manager, and the system background prompt module simultaneously displays a red warning pop-up window in both the power plant's environmental protection maintenance backend and the central control backend. The warning signal continues until manual confirmation and then disappears.

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