A water quality control method and system for a once-through boiler

Abstract

The present invention relates to the field of automation control technology, and particularly to a water quality control method and system for a once-through boiler. The method includes the following steps: collecting liquid sensing signals and temperature sensing signals in the once-through boiler; performing preliminary liquid resistance value calculation processing according to the liquid sensing signals to generate preliminary liquid resistance value data; performing temperature compensation-based liquid resistance value correction processing on the preliminary liquid resistance value data based on the temperature sensing signals to generate liquid resistance value data; performing the water supply operation of the feed water pump of the once-through boiler; performing immediate analysis processing of the liquid conductivity and dissolved solids concentration on the liquid resistance value data according to the water supply operation of the feed water pump to respectively obtain an immediate liquid conductivity signal and immediate dissolved solids concentration data; and performing the sewage discharge control operation of the once-through boiler according to the immediate liquid conductivity signal and the immediate dissolved solids concentration data. The present invention realizes intelligent and efficient water quality sewage discharge control by analyzing the water quality characteristics of the once-through boiler.

Description

Technical Field

[0001] The present invention relates to the technical field of automatic control, and particularly relates to a water quality control method and system for a once-through boiler. Background Art

[0002] A once-through boiler is a vertical boiler in which the boiler body adopts an arrangement form of connecting tube bundles between upper and lower headers. Under the rated working pressure condition, feed water is input from the lower header of the body, flows through more than 2 straight tube bundles connected between the upper and lower headers and is fully heated and then rises to generate rated parameter steam or hot water, and is output from the upper header of the body. The once-through boiler has the characteristics of no steam drum, small water capacity, and low circulation ratio. Since the once-through boiler can complete heating to evaporation in one tube and its circulation ratio is very low, about one percent of that of a natural circulation boiler, it has high requirements for water quality. If water quality management is not emphasized, consequences such as scaling, corrosion, and steam carrying water will occur. Furthermore, it will cause low boiler thermal efficiency, and even burst pipes and cause accidents, affecting the safe operation of the boiler. The boiler water of the once-through boiler mainly controls indicators such as dissolved solids and pH. In order to avoid steam carrying water, it is necessary to control the total dissolved solids (TDS) of the boiler water within a reasonable range. In addition, the dissolved solids concentration (TDS) of the aqueous solution is proportional to the conductivity. The boiler indirectly obtains the TDS value of the water by detecting the conductivity of the aqueous solution through a conductivity sensor to control the TDS value of the boiler water within a reasonable range. However, how to improve the intelligence and automation level of the system while ensuring the accuracy of water quality control for the existing water quality control method of the once-through boiler has become a technical problem to be solved in the field of once-through boiler water quality management. Especially in the case of large temperature changes of the water, how to accurately monitor the conductivity and perform temperature compensation to dynamically adjust the TDS value of the boiler water to avoid problems such as boiler scaling and corrosion and ensure the efficient and safe operation of the boiler is still an important direction of current technological development. Summary of the Invention

[0003] Based on this, the present invention provides a water quality control method and system for a once-through boiler to solve at least one of the above technical problems.

[0004] To achieve the above object, a water quality control method for a once-through boiler includes the following steps:

[0005] Step S1: Use the liquid monitoring sensor and temperature monitoring sensor built in the once-through boiler to monitor and process the liquid sensing signal and temperature sensing signal of the once-through boiler, respectively generate the liquid sensing signal and temperature sensing signal; perform preliminary liquid resistance value calculation processing according to the liquid sensing signal to generate preliminary liquid resistance value data;

[0006] Step S2: Perform temperature compensation-based liquid resistance value correction processing on the preliminary liquid resistance value data based on the temperature sensing signal to generate liquid resistance value data;

[0007] Step S3: Perform the water supply operation of the once-through boiler feed pump; analyze and process the liquid resistance data for the instantaneous liquid conductivity and dissolved solids concentration according to the water supply operation of the feed pump, and obtain the instantaneous liquid conductivity signal and the instantaneous dissolved solids concentration data respectively;

[0008] Step S4: Perform the blowdown control operation of the once-through boiler according to the instantaneous liquid conductivity signal and the instantaneous dissolved solids concentration data; analyze the water quality blowdown control feedback data according to the blowdown control operation, and generate the water quality blowdown control feedback data.

[0009] Further, step S1 includes the following steps:

[0010] Step S11: Use the liquid monitoring sensor and temperature monitoring sensor built in the once-through boiler to monitor and process the liquid sensing signal and temperature sensing signal of the once-through boiler, and generate the liquid sensing signal and temperature sensing signal respectively;

[0011] Step S12: Perform liquid current detection processing on the liquid sensing signal to generate a liquid current signal;

[0012] Step S13: Perform preliminary liquid resistance calculation processing according to the liquid current signal to generate preliminary liquid resistance data.

[0013] Further, step S2 includes the following steps:

[0014] Step S21: Perform temperature electro-variable signal conversion processing on the temperature sensing signal to generate a temperature electro-variable signal; analyze the boiler temperature data according to the temperature electro-variable signal to generate boiler temperature data;

[0015] Step S22: Obtain the historical liquid resistance-thermodynamics correlation data of the once-through boiler;

[0016] Step S23: Design a correlation influence prediction model for liquid resistance and temperature compensation based on the historical liquid resistance-thermodynamics correlation data of the once-through boiler, and generate a liquid resistance temperature compensation correlation model;

[0017] Step S24: Use the liquid resistance temperature compensation correlation model to analyze the temperature-compensated liquid resistance correction data of the boiler temperature data, and generate temperature-compensated liquid resistance correction data;

[0018] Step S25: Perform temperature-compensated liquid resistance correction processing on the preliminary liquid resistance data through the temperature-compensated liquid resistance correction data to generate liquid resistance data.

[0019] Further, step S23 includes the following steps:

[0020] Step S231: Perform division processing on the resistance values of the liquid samples according to the historical liquid resistance-thermal correlation data to generate divided liquid sample resistance data; perform specific analysis on the resistance values of the divided liquid sample resistance data to generate liquid sample resistance specificity data;

[0021] Step S232: Perform analysis processing on the temperature influence coefficient of resistance specificity for the historical through-flow boiler liquid resistance-thermal correlation data through the liquid sample resistance specificity data to generate the temperature influence coefficient of resistance specificity;

[0022] Step S233: Perform non-linear temperature influence characteristic analysis on the resistance values of each specific type of liquid according to the temperature influence coefficient of resistance specificity to generate liquid resistance non-linear temperature influence characteristic data;

[0023] Step S234: Use the liquid resistance non-linear temperature influence characteristic data as the radial basis kernel parameter, and perform analysis on the correlation influence mapping relationship between the liquid resistance and temperature compensation by using the support vector machine algorithm and the radial basis kernel parameter to generate a liquid resistance temperature compensation correlation model.

[0024] Further, step S3 includes the following steps:

[0025] Step S31: Perform digital signal conversion processing on the liquid conductivity according to the liquid resistance data to generate a liquid conductivity signal;

[0026] Step S32: Perform analysis on the dissolved solids concentration according to the liquid conductivity digital signal to generate dissolved solids concentration data;

[0027] Step S33: Perform the water supply operation of the feed pump of the through-flow boiler, and perform real-time update processing on the liquid conductivity digital signal and the dissolved solids concentration data according to the water supply operation of the feed pump to obtain the real-time liquid conductivity signal and the real-time dissolved solids concentration data respectively.

[0028] Further, wherein the continuous blowdown liquid conductivity threshold is greater than the continuous blowdown start conductivity threshold, and the continuous blowdown start conductivity threshold is greater than the continuous blowdown stop conductivity threshold, step S4 includes the following steps:

[0029] Wherein the execution of the blowdown control operation of the through-flow boiler includes steps S41 to S46, and the water quality blowdown control feedback data analysis is step S47;

[0030] Step S41: When the real-time liquid conductivity signal is not less than the preset continuous blowdown start conductivity threshold and the dissolved solids concentration data is not less than the preset dissolved solids concentration threshold, perform the continuous blowdown control operation of the through-flow boiler;

[0031] Step S42: Monitor and process the liquid conductivity signal and the instantaneous dissolved solids concentration data for continuous blowdown according to the continuous blowdown control operation, to obtain the continuous blowdown liquid conductivity signal and the continuous blowdown dissolved solids concentration data;

[0032] Step S43: Conduct a time-series trend analysis on the continuous blowdown conductivity signal to generate continuous blowdown conductivity trend data;

[0033] Step S44: When the continuous blowdown conductivity trend data is in an increasing trend, execute Step S45; or, when the continuous blowdown conductivity trend data is in a decreasing trend, execute Step S46;

[0034] Step S45: Continuously monitor the continuous blowdown liquid conductivity signal until the continuous blowdown liquid conductivity signal is not less than the preset continuous blowdown liquid conductivity threshold: Conduct auxiliary blowdown control processing on the continuous blowdown control operation to obtain an auxiliary blowdown control operation; Conduct the first water quality blowdown control feedback data analysis according to the auxiliary blowdown control operation to generate the first water quality blowdown control feedback data;

[0035] Step S46: When the continuous blowdown liquid conductivity signal is less than the preset continuous blowdown stop conductivity threshold or the continuous blowdown dissolved solids concentration data is less than the preset dissolved solids concentration threshold: Conduct blowdown end control processing on the continuous blowdown control operation to obtain a second blowdown end control operation; Conduct the second water quality blowdown control feedback data analysis on the corresponding continuous blowdown liquid conductivity signal and the continuous blowdown dissolved solids concentration data through the second blowdown end control operation to generate the second water quality blowdown control feedback data;

[0036] Step S47: Conduct water quality blowdown control feedback data analysis according to the first water quality blowdown control feedback data or the second water quality blowdown control feedback data to generate water quality blowdown control feedback data.

[0037] Further, the execution of the continuous blowdown control operation of the once-through boiler in Step S41 includes the following steps:

[0038] Conduct blowdown demand quantification assessment processing according to the instantaneous liquid conductivity signal and the instantaneous dissolved solids concentration data to generate blowdown demand quantification assessment data; Conduct adaptive blowdown throttle orifice adjustment parameter analysis according to the blowdown demand quantification assessment data to generate adaptive blowdown throttle orifice adjustment parameters; Execute the continuous blowdown control operation of the once-through boiler based on the adaptive blowdown throttle orifice adjustment parameters.

[0039] Further, the conduct of auxiliary blowdown control processing on the continuous blowdown control operation to obtain an auxiliary blowdown control operation in Step S45 includes the following steps:

[0040] Execute feed water synchronous stop control for the feed water operation of the feed water pump, and maintain sewage control for the continuous sewage control operation; perform auxiliary sewage control operation marking based on the feed water operation of the feed water pump under feed water synchronous stop control and the continuous sewage control operation of sewage control to obtain an auxiliary sewage control operation.

[0041] Further, the first water quality sewage control feedback data analysis according to the auxiliary sewage control operation in step S45 includes the following steps:

[0042] Monitor and process the liquid conductivity and dissolved solids concentration of auxiliary sewage for the continuous sewage liquid conductivity signal and continuous sewage dissolved solids concentration data according to the auxiliary sewage control operation to obtain an auxiliary sewage liquid conductivity signal and auxiliary sewage dissolved solids concentration data;

[0043] When the auxiliary sewage liquid conductivity signal is less than the preset continuous sewage stop conductivity threshold or the auxiliary sewage dissolved solids concentration data is less than the preset dissolved solids concentration threshold, perform sewage end control processing on the auxiliary sewage control operation to obtain a first sewage end control operation, and generate first water quality sewage control feedback data by performing first water quality sewage control feedback data analysis on the corresponding auxiliary sewage liquid conductivity signal and auxiliary sewage dissolved solids concentration data through the first sewage end control operation.

[0044] This specification provides a water quality control system for a once-through boiler, which is used to execute the water quality control method of the once-through boiler as described above. The water quality control system of the once-through boiler includes:

[0045] A preliminary liquid resistance analysis module, which is used to monitor and process the liquid perception signal and temperature perception signal of the once-through boiler by using the liquid monitoring sensor and temperature monitoring sensor built in the once-through boiler, and generate a liquid perception signal and a temperature perception signal respectively; perform preliminary liquid resistance calculation processing according to the liquid perception signal to generate preliminary liquid resistance data;

[0046] A liquid resistance temperature compensation analysis module, which is used to perform temperature compensation liquid resistance correction processing on the preliminary liquid resistance data based on the temperature perception signal to generate liquid resistance data;

[0047] A once-through boiler feed water analysis module, which is used to execute the feed water operation of the feed water pump of the once-through boiler; perform instant liquid conductivity and dissolved solids concentration analysis processing on the liquid resistance data according to the feed water operation of the feed water pump to obtain an instant liquid conductivity signal and instant dissolved solids concentration data respectively;

[0048] A once-through boiler blowdown control module is used to perform the blowdown control operation of the once-through boiler according to the instant liquid conductivity signal and the instant dissolved solids concentration data; analyze the water quality blowdown control feedback data according to the blowdown control operation, and generate the water quality blowdown control feedback data.

[0049] The beneficial effects of this application are as follows. By combining the use of a liquid monitoring sensor and a temperature monitoring sensor, the present invention realizes the real-time monitoring and precise control of the water quality of a once-through boiler. The built-in liquid monitoring sensor is used to collect liquid sensing signals, and in combination with the temperature monitoring sensor, temperature sensing signals are generated to reflect the state and temperature changes of the boiler water. This enables the monitoring of water quality changes at any time during the operation of the boiler, ensuring a rapid response to water quality management. The liquid sensing signals are processed through current detection to generate liquid current signals, effectively converting the conductivity of the liquid into current signals and providing accurate inputs for subsequent liquid resistance calculations. Based on the real-time liquid current signals, a preliminary estimate of the water resistance is made, which preliminarily reflects the concentration of dissolved solids in the boiler water. The temperature sensing signals are converted into temperature electrical variable signals to generate boiler temperature data. The temperature change of the boiler directly affects the conductivity and dissolved solid concentration of water. Therefore, through the real-time monitoring of temperature data, the changes in water quality can be accurately judged, and errors caused by temperature fluctuations can be avoided. By obtaining the historical liquid resistance-thermal correlation data of the once-through boiler, the system is helped to identify the correlation law between temperature and liquid resistance, and a theoretical basis is provided for resistance correction based on temperature changes. Through the analysis of liquid sample resistance specificity, temperature influence coefficient analysis, non-linear temperature influence characteristic analysis, and support vector machine algorithm analysis of radial basis kernel parameters, a correlation influence prediction model of liquid resistance and temperature compensation is accurately designed. Through in-depth exploration of the relationship between liquid resistance and temperature, the temperature compensation of liquid resistance can be carried out more precisely, avoiding water quality control errors caused by temperature changes, being able to compensate for temperature effects in real time and accurately, and improving the level of intelligence and automation. Based on the liquid resistance temperature compensation correlation model, the boiler temperature data is compensated, greatly improving the sensitivity of the system to water quality changes, enabling more precise and efficient water quality control. Through the correction of liquid resistance by temperature compensation, the accumulation of errors caused by temperature changes is avoided, ensuring the stable operation of the once-through boiler under various working conditions. The digital signal of the liquid resistance data is converted into a liquid conductivity signal, which intuitively reflects the water quality changes. Conductivity is a common indicator for measuring dissolved solids in water. Therefore, converting the liquid resistance into a conductivity signal provides more accurate basic data for water quality monitoring. The concentration of dissolved solids is further analyzed through the liquid conductivity digital signal. The concentration of dissolved solids is an important parameter in the water quality control of once-through boilers. By real-time monitoring the concentration of dissolved solids, water quality anomalies can be detected in a timely manner. By performing the water supply operation of the feed pump and instantaneously updating the liquid conductivity signal and the concentration data of dissolved solids according to the operation of the feed pump, the real-time and accuracy of water quality monitoring are ensured. Each water supply operation will affect the water quality state in the boiler. Timely updating the liquid conductivity and the concentration data of dissolved solids enables rapid adjustment of the water quality control strategy according to the operating conditions of the boiler.When the liquid conductivity and dissolved solids concentration reach the preset thresholds, the system automatically initiates continuous blowdown control operations, which can timely control the water quality changes inside the boiler and avoid adverse effects such as corrosion and scaling caused by poor water quality. Through precise threshold settings, it ensures that the blowdown operations are only carried out when necessary, improving the blowdown efficiency and reducing energy waste. Also, through quantification and assessment of blowdown requirements and analysis of adaptive blowdown throttle orifice adjustment parameters, the precision of blowdown operations is improved, and the blowdown operation becomes more flexible and intelligent. Through adaptive adjustment, according to the actual water quality situation, the intensity of blowdown operations is timely adjusted, avoiding over-blowdown or insufficient blowdown situations, thus achieving precise control of water quality. Through monitoring of continuous blowdown liquid conductivity and dissolved solids concentration, time-series trend analysis, and trend judgment, the system can react timely to water quality changes. When the conductivity trend rises, the system continuously strengthens blowdown until the conductivity reaches the preset value; when the conductivity drops, the system reduces or stops blowdown. Through trend analysis, intelligent water quality adjustment is achieved, making the blowdown operation not only based on instant data but also combined with historical data and trends, further enhancing the scientificity and rationality of blowdown control. When the continuous blowdown liquid conductivity signal does not meet the conditions for stopping blowdown, the system conducts auxiliary blowdown control to maintain strict control over the boiler water quality and avoid problems of abnormal boiler water quality caused by premature termination of blowdown. Through synchronous stop control of the feed pump water supply operation, the coherence and stability of blowdown control operations are ensured. At the same time, according to the auxiliary blowdown control operation, water quality blowdown control feedback analysis is carried out to optimize blowdown operations. Through precise marking of blowdown behavior and data analysis, water quality control becomes more systematic and automated, and can be adjusted in real time according to water quality feedback data.

[0050] Therefore, the water quality control method of the once-through boiler of the present invention can, through the combined use of the liquid monitoring sensor and the temperature monitoring sensor built in the once-through boiler, monitor the conductivity and temperature changes of the water quality in the boiler in real time, and precisely adjust the resistance value data of the liquid through temperature compensation processing. The correlation compensation model between the liquid resistance and temperature is designed based on historical liquid resistance-thermal correlation data, can dynamically adapt to temperature changes, and accurately calculate the impact of temperature changes on water quality, so as to optimize the TDS (total dissolved solids) value of the boiler water. Through this intelligent dynamic adjustment, the water quality fluctuations caused by temperature fluctuations can be effectively avoided, thereby minimizing the risk of boiler scaling and corrosion to the greatest extent and extending the service life of the boiler. In addition, a blowdown control mechanism based on the instant liquid conductivity and dissolved solids concentration data is introduced. Combining with the liquid conductivity signal corrected by temperature compensation, it can accurately evaluate the blowdown demand and adaptively adjust the blowdown intensity. By continuously monitoring the liquid conductivity and dissolved solids concentration and judging the water quality change trend through time series trend analysis, the system can intelligently adjust the blowdown operation, thereby ensuring the water quality control accuracy while avoiding energy waste or water quality abnormalities caused by excessive or insufficient blowdown. Providing accurate real-time feedback for water quality changes ensures that the boiler is always in the best operating state. The system not only has a high level of automation and can automatically complete water quality monitoring, analysis and control, but also can intelligently adjust the operation strategy according to different working conditions, greatly improving the water quality management efficiency of the boiler. At the same time, the precise blowdown control also effectively reduces the frequency and intensity of the blowdown operation, further improving the energy use efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] Figure 1 It is a schematic flow chart of the steps of a water quality control method for a once-through boiler of the present invention;

[0052] Figure 2 is Figure 1 a detailed implementation step flow chart of step S4 in

[0053] The realization, functional features and advantages of the object of the present invention will be further described with reference to the embodiments and the accompanying drawings. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0054] The technical method of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those skilled in the art within the scope of the present invention without creative work based on the embodiments of the present invention belong to the scope of protection of the present invention.

[0055] In addition, the accompanying drawings are only schematic illustrations of the present invention and are not necessarily drawn to scale. The same reference numerals in the drawings denote the same or similar parts, and thus repeated descriptions thereof will be omitted. Some of the block diagrams shown in the drawings are functional entities and do not necessarily correspond to physically or logically independent entities. The functional entities may be implemented in software form, or in one or more hardware modules or integrated circuits, or in different networks and / or processor methods and / or microcontroller methods.

[0056] It should be understood that although the terms "first", "second", etc. may be used herein to describe various units, these units should not be limited by these terms. These terms are only used to distinguish one unit from another. For example, without departing from the scope of the exemplary embodiments, the first unit may be referred to as the second unit, and similarly the second unit may be referred to as the first unit. The term "and / or" used herein includes any and all combinations of one or more of the associated listed items.

[0057] To achieve the above object, please refer to Figures 1 to 2 , the present invention provides a water quality control method for a once-through boiler. In an embodiment of the present invention, please refer to Figure 1 shown, which is a schematic flowchart of the steps of a water quality control method for a once-through boiler according to the present invention. The water quality control method for the once-through boiler includes the following steps:

[0058] Step S1: Use the liquid monitoring sensor and the temperature monitoring sensor built in the once-through boiler to monitor and process the liquid perception signal and the temperature perception signal of the once-through boiler, respectively generate the liquid perception signal and the temperature perception signal; perform preliminary liquid resistance value calculation processing according to the liquid perception signal to generate preliminary liquid resistance value data;

[0059] In an embodiment of the present invention, the automatic boiler water control system consists of a control panel, a feed water pump, a chemical dosing device, a conductivity sensor, a thermistor, a continuous blowdown solenoid valve, and an orifice. The liquid monitoring sensor and the temperature monitoring sensor are installed at key positions of the boiler, such as the feed water pipeline, the steam pipeline, and the circulating water area inside the boiler. These sensors are respectively connected to the central control system through a wireless or wired network to collect liquid sensing signals and temperature sensing signals in real time. The liquid monitoring sensor includes two mutually insulated electrodes. The electrode material is often type 316 stainless steel, and the electrodes have specific sizes and spacings. By measuring the conductivity or impedance of the water in the boiler, a liquid sensing signal is generated. The processing of the liquid sensing signal is carried out by a data acquisition system, and the data acquisition frequency is set to once per second to ensure a real-time response to water quality changes. The liquid sensing signal is converted into liquid resistance value data through a conductivity measurement circuit. The liquid resistance is detected by connecting to a sensor immersed in the liquid. An alternating voltage is applied to the sensor by the detection circuit, and the magnitude of the generated current is measured, and then converted into a conductivity value through a conductivity detection conversion circuit. The liquid current detection circuit is used to detect the current signal passing through the liquid. The liquid sensing signal is subjected to liquid current detection processing through the liquid current detection circuit to generate a liquid current signal. According to the conductivity detection conversion circuit, a preliminary liquid resistance calculation is performed on the liquid sensing signal. By continuously monitoring the liquid current signal and performing real-time calculations, the accuracy and real-time nature of the boiler water quality data are ensured, and preliminary liquid resistance value data is generated. In this way, the entire liquid resistance calculation process can be completed with very high precision and speed, and since the relationship between the liquid resistance and the dissolved substances in the water is directly related, it can accurately reflect the changes in water quality.

[0060] Step S2: Perform a liquid resistance correction process with temperature compensation on the preliminary liquid resistance value data based on the temperature sensing signal to generate liquid resistance value data;

[0061] In the embodiments of the present invention, the temperature monitoring sensor uses a thermocouple or an RTD sensor, which is installed in the upstream and downstream areas of the water flow in the boiler to accurately record the temperature change of the water in the boiler. The temperature signal output by the sensor is converted into a standard electrical signal through the temperature sensor signal processing module and sent to the central control system. The acquisition frequency of the temperature signal is also once per second, and the temperature signal is converted into boiler temperature data through the temperature compensation detection conversion circuit. The temperature compensation detection conversion circuit includes a temperature sensing power generation circuit, a sensor current detection circuit, and a sensor current conversion circuit. For example, the temperature signal output by the sensor is usually an analog signal. After being processed by the temperature electrical variable signal conversion, it is converted into a standardized electrical variable signal, and an analog-to-digital converter (ADC) is used to convert the analog signal into a digital signal to determine the actual value of the boiler water temperature. The historical liquid resistance-thermal correlation data of the once-through boiler is collected and stored in the database. Based on the historical liquid resistance-thermal correlation data, a correlation influence prediction model of liquid resistance and temperature compensation is designed. The design of this model requires analyzing the non-linear relationship between liquid resistance and temperature in order to account for the change of liquid resistance with different temperature compensations. For example, it is assumed that through historical data analysis, it is found that the liquid resistance shows a non-linear downward trend as the temperature rises. Through regression analysis methods, such as the support vector machine (SVM) algorithm, a liquid resistance temperature compensation model is designed based on this data. The core of the model is to calculate the correction coefficient of the liquid resistance at this temperature according to the temperature change. The model predicts and corrects the liquid resistance by calculating the correlation coefficient between the liquid resistance and the temperature. The designed model can be applied to different boiler types and operating conditions, providing an accurate basis for subsequent liquid resistance compensation processing. By applying the designed liquid resistance temperature compensation correlation model, the temperature compensation liquid resistance correction data analysis of the temperature data of the boiler is carried out. During this process, the system uses the model to output the correction coefficient according to the current boiler water temperature and historical data for the temperature compensation of the liquid resistance. Through the temperature compensation liquid resistance correction data, the preliminary liquid resistance data is subjected to temperature compensation liquid resistance correction processing to generate liquid resistance data. The purpose of this processing is to further improve the accuracy of the liquid resistance data to avoid scaling and corrosion problems caused by water quality changes in the boiler. The entire temperature compensation and liquid resistance correction process, combined with real-time data and historical experience, ensures the water quality control accuracy of the once-through boiler, and can dynamically adapt to the changes in water quality and temperature during boiler operation, thereby improving the automation and intelligence level of the boiler system and ensuring its efficient and safe operation.

[0062] Step S3: Perform the water supply operation of the feed pump of the once-through boiler; perform immediate analysis and processing of the liquid conductivity and dissolved solids concentration on the liquid resistance data according to the water supply operation of the feed pump, and obtain the immediate liquid conductivity signal and the immediate dissolved solids concentration data respectively;

[0063] In the embodiments of the present invention, digital signal conversion processing of the liquid conductivity is performed based on the liquid resistance data. The liquid resistance signal is usually collected by a sensor and then processed to be converted into a conductivity signal. Conductivity is the ability of dissolved ions in a liquid to conduct current, and the conductivity of a liquid is inversely proportional to its resistance. In practical applications, the liquid resistance sensor outputs the resistance data in the form of an analog signal. Through the single-chip microcomputer conversion module, the standard voltage signal corresponding to the liquid resistance converted by the conductivity detection conversion circuit is converted into a digital conductivity value signal and provided for the internal control program to use, generating a liquid conductivity signal. The dissolved solids concentration is analyzed according to the liquid conductivity digital signal. The concentration of total dissolved solids (TDS) is usually linearly correlated with the liquid conductivity. The higher the conductivity, the greater the concentration of dissolved solids. Therefore, the dissolved solids are calculated through the historical environmental assessment factors, the TDS concentration calculation formula, and the empirical constants obtained through experiments. The water supply operation of the feed pump of the once-through boiler is performed, and the liquid conductivity digital signal and the dissolved solids concentration data are updated immediately according to the water supply operation of the feed pump. During the operation of the feed pump, the water quality of the boiler may fluctuate due to the change of the water volume. Therefore, it is necessary to continuously update the liquid conductivity and the dissolved solids concentration data. During the real-time data update process, the liquid conductivity and TDS concentration data will be transmitted to the control system for necessary analysis and feedback adjustment. For example, if it is detected that the liquid conductivity exceeds the preset threshold, the system can start sewage discharge or adjust the water supply volume to reduce the concentration of dissolved solids in the liquid, avoiding problems such as boiler scaling or corrosion.

[0064] Step S4: Perform the sewage discharge control operation of the once-through boiler according to the instant liquid conductivity signal and the instant dissolved solids concentration data; perform data analysis on the water quality sewage discharge control feedback according to the sewage discharge control operation, and generate water quality sewage discharge control feedback data.

[0065] In the embodiment of the present invention, the blowdown control operation of the once-through boiler is performed according to the instant liquid conductivity signal and the instant dissolved solid concentration data. The blowdown control operation of the once-through boiler includes: the opening condition of the continuous blowdown solenoid valve. For example, during water supply, the dissolved solid concentration data is not less than 1800 mg / L (the preset dissolved solid concentration threshold), and the conductivity of the boiler water is not less than the set value of the starting conductivity of continuous blowdown. (The set value of the starting conductivity of continuous blowdown K1 = 3000 μs / cm). The closing condition of the continuous blowdown solenoid valve. For example, during water supply, the dissolved solid concentration data is less than 1500 mg / L (the preset dissolved solid concentration threshold) or the conductivity of the boiler water is less than the set value of the ending conductivity of continuous blowdown. (The set value of the ending conductivity of continuous blowdown K2 = 2500 μs / cm). The auxiliary continuous blowdown function. For example, when the normal continuous blowdown is opened and the conductivity of the boiler water does not decrease and reaches above (K1 + 500) μs / cm, the water supply synchronization of the continuous blowdown is released, and the continuous blowdown continues for the water supply time (the on-off time of water supply) even when the water supply stops, ensuring the blowdown volume. In the case of the normal continuous blowdown function, the continuous blowdown valve is opened simultaneously during water supply, and the continuous blowdown solenoid valve is closed when the water supply pump stops. When the auxiliary continuous blowdown function operates, the water supply synchronization condition of the continuous blowdown is released, and the continuous blowdown valve continues to be opened after the water supply stops for the water supply time (the on-off time of water supply), and then the continuous blowdown valve is closed. (Since the opening time of the blowdown valve is twice that of the previous continuous blowdown time, the blowdown rate can also reach twice). This operation is released after the conductivity of the boiler water drops below the set value of the ending conductivity of continuous blowdown and returns to the normal continuous blowdown operation. According to the change trend of the instant liquid conductivity signal and the instant dissolved solid concentration data corresponding to the monitored blowdown control operation, the system generates water quality blowdown control feedback data. Specifically, when the liquid conductivity and the dissolved solid concentration continue to decrease and tend to be stable, the system considers that the blowdown effect has reached the best state, and then summarizes the water quality blowdown control feedback data. These data not only provide an evaluation of the current blowdown operation effect, but also provide data support and optimization basis for the next round of blowdown control operation.

[0066] Further, step S1 includes the following steps:

[0067] Step S11: Use the liquid monitoring sensor and the temperature monitoring sensor built in the once-through boiler to monitor and process the liquid perception signal and the temperature perception signal of the once-through boiler, and generate the liquid perception signal and the temperature perception signal respectively;

[0068] Step S12: Perform liquid current detection processing on the liquid perception signal to generate a liquid current signal;

[0069] Step S13: Perform preliminary liquid resistance value calculation processing based on the liquid current signal to generate preliminary liquid resistance value data.

[0070] In the embodiment of the present invention, the automatic boiler water control system consists of a control panel, a feed water pump, a chemical dosing device, a conductivity sensor, a thermistor, a continuous blowdown solenoid valve, and an orifice. The liquid monitoring sensor and the temperature monitoring sensor are installed at key positions of the boiler, such as the feed water pipe, the steam pipe, and the circulating water area inside the boiler. These sensors are respectively connected to the central control system through wireless or wired networks to collect liquid perception signals and temperature perception signals in real time. The liquid monitoring sensor includes two mutually insulated electrodes. The electrode material is often type 316 stainless steel. The electrodes have specific sizes and spacings. By measuring the conductivity or impedance of the water in the boiler, a liquid perception signal is generated. The processing of the liquid perception signal is carried out by a data acquisition system. The data acquisition frequency is set to once per second to ensure a real-time response to water quality changes. The liquid perception signal is converted into liquid resistance value data through a conductivity measurement circuit. The liquid resistance value is detected by connecting to a sensor immersed in the liquid. An alternating voltage is applied to the sensor by the detection circuit, and the magnitude of the generated current is measured, and then converted into a conductivity value through a conductivity detection conversion circuit. The liquid current detection circuit is used to detect the current signal passing through the liquid. The liquid perception signal is subjected to liquid current detection processing through the liquid current detection circuit to generate a liquid current signal. According to the conductivity detection conversion circuit, the liquid perception signal is subjected to preliminary liquid resistance value calculation. By continuously monitoring the liquid current signal and performing real-time calculation, the accuracy and real-time nature of the boiler water quality data are ensured, and preliminary liquid resistance value data is generated. In this way, the entire liquid resistance value calculation process can be completed with very high precision and speed, and since the relationship between the liquid resistance value and the dissolved substances in the water is directly related, it can accurately reflect the change of water quality.

[0071] Further, step S2 includes the following steps:

[0072] Step S21: Perform temperature-electric variable signal conversion processing on the temperature perception signal to generate a temperature-electric variable signal; perform boiler temperature data analysis based on the temperature-electric variable signal to generate boiler temperature data;

[0073] Step S22: Obtain the historical liquid resistance value-thermal correlation data of the once-through boiler;

[0074] Step S23: Design a correlation influence prediction model for liquid resistance value and temperature compensation based on the historical liquid resistance value-thermal correlation data of the once-through boiler to generate a liquid resistance value temperature compensation correlation model;

[0075] Step S24: Perform temperature compensation liquid resistance value correction data analysis on the boiler temperature data by using the liquid resistance value temperature compensation correlation model to generate temperature compensation liquid resistance value correction data;

[0076] Step S25: Perform liquid resistance calibration processing on the preliminary liquid resistance data through temperature compensation of the liquid resistance correction data to generate liquid resistance data.

[0077] In the embodiments of the present invention, the temperature monitoring sensor uses a thermocouple or an RTD sensor, which is installed in the upstream and downstream areas of the water flow in the boiler to accurately record the temperature change of the water in the boiler. The temperature signal output by the sensor is converted into a standard electrical signal through the temperature sensor signal processing module and sent to the central control system. The acquisition frequency of the temperature signal is also once per second, and the temperature signal is converted into boiler temperature data through the temperature compensation detection conversion circuit. The temperature compensation detection conversion circuit includes a temperature sensing power generation circuit, a sensor current detection circuit, and a sensor current conversion circuit. For example, the temperature signal output by the sensor is usually an analog signal, which is converted into a standardized electrical variable signal after being processed by the temperature electrical variable signal conversion. The conversion process of the temperature signal uses an analog-to-digital converter (ADC) to convert the analog signal into a digital signal. The range of the converted temperature electrical variable signal is usually 0 - 10V, indicating the change in the water temperature of the boiler. In a certain working environment, when the actual water temperature of the boiler is 150°C, the temperature electrical variable signal generated after the conversion of the temperature sensing signal is 5V. The system analyzes the boiler temperature data based on this temperature electrical variable signal to determine the actual value of the boiler water temperature. The historical liquid resistance - thermal correlation data of the once-through boiler is collected and stored in the database. These historical data include the liquid resistance (deduced from the liquid sensing signal and the liquid current signal) under different boiler operating conditions and the corresponding boiler temperature data. These data are accumulated and formed through long-term monitoring of the boiler operating state, based on experimental and on-site data. For example, the historical data of a certain once-through boiler includes the following content: when the temperature is 140°C, the liquid resistance is 300Ω; when the temperature is 160°C, the liquid resistance is 250Ω; when the temperature is 180°C, the liquid resistance is 220Ω. The collection of the historical liquid resistance - thermal correlation data is completed by regularly monitoring, analyzing, and recording the boiler water quality. This dataset will be used for subsequent modeling of the relationship between the liquid resistance and the temperature, and provide a basis for generating the liquid resistance temperature compensation correlation model. By based on the historical liquid resistance - thermal correlation data, a correlation influence prediction model of the liquid resistance and the temperature compensation is designed. The design of this model requires analyzing the non-linear relationship between the liquid resistance and the temperature, so as to determine the change of the liquid resistance according to different temperature compensations. For example, it is assumed that through historical data analysis, it is found that the liquid resistance shows a non-linear decreasing trend as the temperature increases. Through regression analysis methods, such as the support vector machine (SVM) algorithm, a liquid resistance temperature compensation model is designed based on these data. The core of the model is to calculate the correction coefficient of the liquid resistance at this temperature according to the temperature change. Specifically, if the temperature changes by 10°C, the liquid resistance may need to be corrected by 5Ω. The model predicts and corrects the liquid resistance by calculating the correlation coefficient between the liquid resistance and the temperature. The designed model can be applied to different boiler types and operating conditions, providing an accurate basis for the subsequent compensation processing of the liquid resistance.By applying the designed liquid resistance-temperature compensation correlation model, the data analysis of the liquid resistance correction for temperature compensation of the boiler's temperature data is carried out. During this process, the system uses the current boiler water temperature and historical data, and utilizes the model to output a correction coefficient for the temperature compensation of the liquid resistance. For example, assuming the current temperature of the boiler is 150 °C, through model calculation, the predicted liquid resistance correction coefficient at this temperature is 5 Ω. Based on this correction coefficient, the initially measured liquid resistance of the boiler (such as 250 Ω) is corrected to generate the corrected liquid resistance data after temperature compensation, and the new liquid resistance is obtained as 245 Ω. This corrected data more accurately reflects the influence of temperature on the liquid resistance, providing a reliable data basis for subsequent water quality control and adjustment. Through the temperature-compensated liquid resistance correction data, the liquid resistance correction process for temperature compensation of the initially measured liquid resistance data is carried out. The purpose of this processing is to further improve the accuracy of the liquid resistance data to avoid problems such as scaling and corrosion caused by water quality changes in the boiler. For example, the initially measured liquid resistance is 250 Ω. When the boiler water temperature is 150 °C, after temperature compensation, the corrected value of the liquid resistance is 245 Ω. Subsequently, by comparing historical data and current corrected data, the corrected model is used to further correct the liquid resistance, and finally, accurate liquid resistance data (such as 243 Ω) is obtained. This accurate liquid resistance data can be used as the core parameter for boiler water quality control, helping to adjust the water quality during the operation of the boiler and timely adjusting the blowdown or water supply volume, thereby avoiding the deterioration of water quality from affecting the operation efficiency and safety of the boiler. Finally, the entire process of temperature compensation and liquid resistance correction, combined with real-time data and historical experience, ensures the water quality control accuracy of the once-through boiler and can dynamically adapt to the changes in water quality and temperature during the operation of the boiler, thereby improving the automation and intelligent level of the boiler system and ensuring its efficient and safe operation.

[0078] Further, step S23 includes the following steps:

[0079] Step S231: Perform liquid sample resistance division processing based on historical liquid resistance-thermal correlation data to generate divided liquid sample resistance data; perform liquid sample resistance specificity analysis on the divided liquid sample resistance data to generate liquid sample resistance specificity data;

[0080] Step S232: Perform resistance-specific temperature influence coefficient analysis processing on the historical once-through boiler liquid resistance-thermal correlation data through the liquid sample resistance specificity data to generate resistance-specific temperature influence coefficients;

[0081] Step S233: Perform non-linear temperature influence characteristic analysis on the liquid resistance of each specific type according to the resistance-specific temperature influence coefficient to generate liquid resistance non-linear temperature influence characteristic data;

[0082] Step S234: Use the characteristic data of the non-linear temperature influence on the liquid resistance value as the radial basis kernel parameter, and analyze the correlation influence mapping relationship between the liquid resistance value and temperature compensation by using the support vector machine algorithm and the radial basis kernel parameter, so as to generate a liquid resistance value temperature compensation correlation model.

[0083] In the embodiments of the present invention, the resistance values of liquid samples are divided based on the historical liquid resistance - thermal correlation data. First, the historical liquid resistance data are grouped according to different temperature ranges. For example, a temperature range can be set from 100°C to 200°C, and the liquid resistance range is from 100Ω to 400Ω. According to these conditions, the liquid resistance data are divided into multiple sub - intervals, and each sub - interval represents a different group of liquid sample resistance data. For example, in a practical application scenario, when the temperature of the boiler is between 150°C and 160°C, the liquid resistance range is from 250Ω to 270Ω. According to this interval, all the liquid resistance data measured within this temperature range are grouped together, that is, a group of liquid sample resistance data is generated. The division of these data groups helps in subsequent resistance specificity analysis. Next, the liquid sample resistance specificity analysis is carried out on these divided liquid sample resistance data. This analysis is used to reveal the specific characteristics corresponding to different liquid resistances, such as the rate of change of the resistance of a certain liquid within a certain temperature range. By using statistical analysis methods, such as analysis of variance or cluster analysis, the resistance characteristics of the liquid samples can be obtained. For example, within the above - mentioned 150°C to 160°C interval, the rate of change of the liquid resistance is 2Ω per degree Celsius. After generating this characteristic data, it will provide the necessary basic data for subsequent analysis. The temperature influence coefficient analysis of resistance specificity is carried out on the historical cross - flow boiler liquid resistance - thermal correlation data by using the liquid sample resistance specificity data. The analysis process first identifies the relationship between different liquid sample resistance characteristics and temperature changes. Through regression analysis methods (such as polynomial regression or weighted regression), according to the relationship between the liquid sample resistance specificity data and the historical temperature data, the specific influence coefficient of temperature on liquid resistance is calculated. For example, through analysis, it is found that when the temperature increases by 10°C, the change coefficient of the liquid resistance is 0.3Ω per degree Celsius. These calculated temperature influence coefficients will be used in subsequent temperature compensation calculations. For example, if the boiler temperature rises from 160°C to 170°C, the expected change in the liquid resistance is 3Ω. In this way, the influence of temperature changes on liquid resistance can be accurately predicted, so as to ensure that the water quality control of the boiler can make corresponding adjustments according to the real - time temperature. According to the temperature influence coefficient of resistance specificity, the non - linear temperature influence characteristics of the resistance values of each specific type of liquid are analyzed. By analyzing the non - linear relationship between the resistance values and temperatures of different liquid samples, it is revealed how the liquid resistance changes non - linearly at different temperatures. For example, in a certain specific liquid sample, the change of the liquid resistance with the increase of temperature is not linear, but shows a more complex curve change. By fitting these data, the non - linear temperature influence characteristics of the liquid resistance changing with temperature are generated. For example, within the temperature range of 150°C to 200°C, the change curve of the liquid resistance can be fitted with a quadratic polynomial: Resistance = 200 + 0.5 * Temperature - 0.01 * Temperature squared.According to this fitting equation, the resistance value of the liquid at any temperature can be accurately calculated, thus providing more accurate data for subsequent compensation operations. The non-linear temperature influence characteristic data of the liquid resistance value is used as the radial basis kernel parameter, and the support vector machine (SVM) algorithm is adopted to analyze the correlation influence mapping relationship between the liquid resistance value and temperature compensation. The non-linear influence characteristics of the liquid resistance value and temperature are used as input data, and kernel mapping is performed through the radial basis function (RBF) to transform to a higher-dimensional space. Then, the SVM algorithm is used to train the data to generate a correlation influence model between the liquid resistance value and temperature compensation. Specifically, assume that the data obtained through the previous non-linear temperature influence characteristic analysis is as follows: when the temperature rises from 150 °C to 160 °C, the change in the liquid resistance value is 5 Ω. By inputting these data into the SVM model and training, a mapping relationship is obtained. Based on this model, the compensation correction value of the liquid resistance value brought about by each temperature change can be accurately calculated according to the actually measured boiler temperature data, thus ensuring the accuracy of boiler water quality control. These models are not only applicable to the current boiler water quality adjustment but can also be dynamically adjusted during the operation of the boiler to adapt to different water quality and temperature changes. Effectively taking into account the non-linear influence of temperature changes on the liquid resistance value and adjusting the boiler water quality control measures according to this complex relationship, thereby improving the accuracy and stability of water quality management.

[0084] Further, step S3 includes the following steps:

[0085] Step S31: Perform digital signal conversion processing on the liquid conductivity according to the liquid resistance value data to generate a liquid conductivity signal;

[0086] Step S32: Analyze the concentration of dissolved solids according to the liquid conductivity digital signal to generate dissolved solid concentration data;

[0087] Step S33: Perform the water supply operation of the feed pump for the once-through boiler, and perform real-time update processing on the liquid conductivity digital signal and the dissolved solid concentration data according to the water supply operation of the feed pump to obtain the real-time liquid conductivity signal and the real-time dissolved solid concentration data respectively.

[0088] In the embodiments of the present invention, digital signal conversion processing of liquid conductivity is performed based on liquid resistance data. The liquid resistance signal is usually collected by a sensor and then processed to be converted into a conductivity signal. Conductivity is the ability of dissolved ions in a liquid to conduct current, and the conductivity of a liquid is inversely proportional to its resistance. In practical applications, the liquid resistance sensor outputs resistance data in the form of an analog signal. Through the single-chip microcomputer conversion module, the standard voltage signal corresponding to the liquid resistance converted by the conductivity detection conversion circuit is converted into a digital conductivity value signal and provided for the internal control program to use, generating a liquid conductivity signal. The dissolved solids concentration is analyzed based on the liquid conductivity digital signal. The concentration of total dissolved solids (TDS) is usually linearly correlated with the liquid conductivity. The higher the conductivity, the greater the concentration of dissolved solids. Therefore, the dissolved solids are calculated through historical environmental evaluation factors, the TDS concentration calculation formula, and the empirical constants obtained through experiments. The water supply operation of the feed pump of the once-through boiler is performed, and the liquid conductivity digital signal and the dissolved solids concentration data are updated immediately according to the water supply operation of the feed pump. During the operation of the feed pump, the water quality of the boiler may fluctuate due to changes in the water volume. Therefore, it is necessary to continuously update the liquid conductivity and the dissolved solids concentration data. Assume that the flow rate of the feed pump is 500 liters per minute, and as the water flow increases, the conductivity and TDS concentration of the liquid will gradually change. After the feed pump is started, by real-time monitoring the liquid conductivity sensor and the dissolved solids concentration sensor, the system can obtain the liquid conductivity and TDS concentration in real time. For example, after the feed pump has been operating for 10 minutes, the liquid conductivity signal changes from 3300 μs / cm to 3500 μs / cm, and the dissolved solids concentration increases from 1980 mg / L to 2100 mg / L. Specifically, by updating the liquid conductivity and the dissolved solids concentration, the system can adjust the boiler water quality control strategy to ensure that the water quality meets the preset standards. During the real-time data update process, the liquid conductivity and TDS concentration data will be transmitted to the control system for necessary analysis and feedback adjustment. For example, if it is detected that the liquid conductivity exceeds the preset threshold, the system can start sewage discharge or adjust the water supply volume to reduce the concentration of dissolved solids in the liquid, avoiding problems such as boiler scaling or corrosion.

[0089] Further, as an embodiment of the present invention, refer to Figure 2 shown in Figure 1 is a detailed step flow schematic diagram of step S4 in

[0090] wherein the sewage discharge control operation of the once-through boiler includes steps S41 to S46, and the water quality sewage discharge control feedback data analysis is step S47;

[0091] Step S41: When the instantaneous liquid conductivity signal is not less than the preset continuous blowdown start conductivity threshold and the dissolved solids concentration data is not less than the preset dissolved solids concentration threshold, perform the continuous blowdown control operation of the once-through boiler;

[0092] In the embodiment of the present invention, when performing the continuous blowdown control operation of the once-through boiler, it is necessary to judge according to the real-time values of the liquid conductivity signal and the dissolved solids concentration data. When the instantaneous liquid conductivity signal is not less than the preset continuous blowdown start conductivity threshold and the dissolved solids concentration data is not less than the preset dissolved solids concentration threshold, the continuous blowdown operation is triggered. For example, during water supply, when the dissolved solids concentration data is not less than 1800 mg / L (the preset continuous blowdown start dissolved solids concentration threshold), and the instantaneous liquid conductivity signal is not less than the continuous blowdown start conductivity threshold (the continuous blowdown start conductivity threshold K1 = 3000 μs / cm), the continuous blowdown solenoid valve is opened to perform the continuous blowdown control operation.

[0093] Step S42: According to the continuous blowdown control operation, monitor and process the liquid conductivity and dissolved solids concentration during continuous blowdown for the instantaneous liquid conductivity signal and the instantaneous dissolved solids concentration data, and obtain the continuous blowdown liquid conductivity signal and the continuous blowdown dissolved solids concentration data;

[0094] In the embodiment of the present invention, continuously monitor the instantaneous liquid conductivity signal and the instantaneous dissolved solids concentration data during the continuous blowdown control operation of the once-through boiler, and perform real-time monitoring and label update. The system continuously adjusts the blowdown operation according to the real-time monitoring data, and keeps the water quality within the safe range through the automatic control system to ensure that the boiler equipment does not cause performance degradation due to excessive scaling, so as to obtain the continuous blowdown liquid conductivity signal and the continuous blowdown dissolved solids concentration data.

[0095] Step S43: Perform a time-series trend analysis on the continuous blowdown conductivity signal to generate continuous blowdown conductivity trend data;

[0096] In the embodiment of the present invention, collect time-series window data of the continuous blowdown conductivity signal, analyze the conductivity trend of the continuous blowdown conductivity signal, and generate continuous blowdown conductivity trend data for identifying whether the blowdown rate reaches the new pollution rate.

[0097] Step S44: When the continuous blowdown conductivity trend data is in an increasing trend, perform Step S45; or when the continuous blowdown conductivity trend data is in a decreasing trend, perform Step S46;

[0098] In the embodiment of the present invention, when the continuous blowdown conductivity trend data is in an increasing trend, that is, when the conventional continuous blowdown cannot control the water quality at the water quality safety level, step S45 is executed; or when the continuous blowdown conductivity trend data is in a decreasing trend, that is, when the conventional continuous blowdown can control the water quality at the water quality safety level, step S46 is executed.

[0099] Step S45: Continuously monitor the continuous blowdown liquid conductivity signal until the continuous blowdown liquid conductivity signal is not less than the preset continuous blowdown liquid conductivity threshold: perform auxiliary blowdown control processing on the continuous blowdown control operation to obtain an auxiliary blowdown control operation; perform first water quality blowdown control feedback data analysis according to the auxiliary blowdown control operation, and generate first water quality blowdown control feedback data;

[0100] In the embodiment of the present invention, when continuous blowdown is started and the boiler water conductivity does not decrease until the continuous blowdown liquid conductivity signal reaches above the continuous blowdown liquid conductivity threshold (K1 + 500) μs / cm, the feed water synchronization of continuous blowdown is released, that is, continuous blowdown with a continuous feed water time (the on-off time of feed water) is still carried out even when the feed water stops, to ensure the blowdown volume. During the continuous blowdown function, the continuous blowdown valve is opened simultaneously when feeding water, and the continuous blowdown solenoid valve is closed when the feed water pump stops. When the auxiliary continuous blowdown function acts, the feed water synchronization condition of continuous blowdown is released, and the continuous blowdown valve continues to be opened after the feed water stops for a duration of the feed water time (the on-off time of feed water), and then the continuous blowdown valve is closed. (Since the opening time of the blowdown valve is twice that of the previous continuous blowdown time, the blowdown rate can also reach twice). This action is released after the boiler water conductivity drops below the continuous blowdown end conductivity threshold (the continuous blowdown end conductivity threshold K2 = 2500 μs / cm), and returns to the conventional continuous blowdown operation. And perform first water quality blowdown control feedback data on the auxiliary blowdown control operation after completion, that is, analyze the liquid conductivity and TDS concentration of the water quality blowdown at the end of blowdown, and generate first water quality blowdown control feedback data.

[0101] Step S46: When the continuous blowdown liquid conductivity signal is less than the preset continuous blowdown stop conductivity threshold or the continuous blowdown dissolved solids concentration data is less than the preset dissolved solids concentration threshold: perform blowdown end control processing on the continuous blowdown control operation to obtain a second blowdown end control operation; perform second water quality blowdown control feedback data analysis on the corresponding continuous blowdown liquid conductivity signal and continuous blowdown dissolved solids concentration data through the second blowdown end control operation, and generate second water quality blowdown control feedback data;

[0102] In an embodiment of the present invention, during water supply, for continuous blowdown control, when the dissolved solids concentration data of the continuous blowdown dissolved solids concentration is less than 1500 mg / L (the preset continuous blowdown end dissolved solids concentration threshold) or the continuous blowdown liquid conductivity signal is less than the continuous blowdown end conductivity threshold (the continuous blowdown end conductivity threshold K2 = 2500 μs / cm), blowdown end control processing is performed on the continuous blowdown control operation, that is, the blowdown valve is closed to obtain the second blowdown end control operation. Through the second blowdown end control operation, the corresponding continuous blowdown liquid conductivity signal and the continuous blowdown dissolved solids concentration data are subjected to second water quality blowdown control feedback data analysis, that is, the liquid conductivity and dissolved solids concentration after blowdown are obtained, and second water quality blowdown control feedback data is generated.

[0103] Step S47: Perform water quality blowdown control feedback data analysis based on the first water quality blowdown control feedback data or the second water quality blowdown control feedback data to generate water quality blowdown control feedback data.

[0104] In an embodiment of the present invention, water quality blowdown control feedback is performed according to the corresponding first water quality blowdown control feedback data or the second water quality blowdown control feedback data by automatic execution to generate water quality blowdown control feedback data.

[0105] Further, the continuous blowdown control operation of the once-through boiler described in step S41 includes the following steps:

[0106] Perform blowdown demand quantification assessment processing according to the instant liquid conductivity signal and the instant dissolved solids concentration data to generate blowdown demand quantification assessment data; perform adaptive blowdown throttle orifice adjustment parameter analysis according to the blowdown demand quantification assessment data to generate adaptive blowdown throttle orifice adjustment parameters; perform the continuous blowdown control operation of the once-through boiler based on the adaptive blowdown throttle orifice adjustment parameters.

[0107] In the embodiment of the present invention, during the water quality control of the once-through boiler, the primary task of performing continuous blowdown control operation is to evaluate the blowdown requirement based on the instantaneous liquid conductivity signal and the instantaneous dissolved solids concentration data. First, the instantaneous conductivity signal and the dissolved solids concentration data are obtained through the conductivity sensor and the dissolved solids sensor installed in the boiler. Assume the real-time data is as follows: instantaneous liquid conductivity signal: 3300 μs / cm, instantaneous dissolved solids concentration data: 1980 mg / L. Based on these data, the system will perform a quantification evaluation process of the blowdown requirement, and analyze the adaptive blowdown throttle orifice adjustment parameters using the quantification evaluation data of the blowdown requirement. According to the blowdown volume requirement and the blowdown capacity of the system, the adjustment range of the throttle orifice is analyzed and determined. For example, if the current blowdown requirement is 10 tons per hour and the maximum opening of the throttle orifice is 100%, then according to the analysis result, the adjustment parameter of the throttle orifice is 75%. This parameter ensures that the blowdown speed can effectively reduce the dissolved solids concentration in the boiler water without causing excessive emissions, ensuring the rational use of resources. Based on the adaptive blowdown throttle orifice adjustment parameters, the continuous blowdown control operation of the once-through boiler is performed. The specific operation is to control the opening of the blowdown valve and adjust the flow rate of the feed water pump to make the blowdown process match the real-time water quality monitoring data. Assume that in this example, the throttle orifice opening is adjusted to 75%, and the system will continuously monitor the changes in the liquid conductivity and the dissolved solids concentration to ensure that the blowdown operation proceeds as expected. If the conductivity or the dissolved solids concentration continues to rise, the system will further increase the blowdown volume according to the adaptive control strategy, such as an auxiliary blowdown control operation.

[0108] Further, the auxiliary blowdown control process for the continuous blowdown control operation in step S45 to obtain the auxiliary blowdown control operation includes the following steps:

[0109] Execute the feed water synchronous stop control for the feed water pump operation, and maintain the blowdown control for the continuous blowdown control operation; perform an auxiliary blowdown control operation marking based on the feed water pump operation with the feed water synchronous stop control and the continuous blowdown control operation with the blowdown control to obtain the auxiliary blowdown control operation.

[0110] In an embodiment of the present invention, when performing the continuous blowdown control operation of a once-through boiler, when the conductivity signal of the blowdown liquid is not less than the preset continuous blowdown liquid conductivity threshold value of (K1 + 500) μs / cm or more, or the dissolved solids concentration data is not less than the corresponding dissolved solids concentration, it enters the auxiliary blowdown control processing stage. The goal of this stage is to avoid the boiler water quality from rising due to premature termination of blowdown, thereby affecting the safety and efficiency of the boiler. In the specific implementation process, first, the feed water synchronous stop control is executed, that is, the feed water operation of the feed water pump is temporarily stopped. This operation is to control the rising speed of the water quality and avoid the influence of the newly added feed water on the dissolved solids concentration in the boiler. After executing the feed water synchronous stop control, the original continuous blowdown control operation is continued. At this time, the blowdown valve maintains a certain opening degree and continues the blowdown operation according to the previous blowdown strategy. To better manage and control the blowdown process, the system will mark this operation as an auxiliary blowdown control operation. Specifically, the system marks it as an auxiliary blowdown control operation by recording data such as the blowdown control state, feed water stop time, and blowdown flow rate at each moment. This mark will help the subsequent system analyze whether there are any links that need to be adjusted during the blowdown process to ensure that the boiler water quality can be maintained at a safe level before the end of the blowdown control operation. The implementation mark of the auxiliary blowdown control operation helps the system automatically adjust the blowdown strategy during the review and analysis of the boiler water quality management process. If it is found through real-time monitoring that the dissolved solids concentration further decreases or the water quality recovers prematurely, the system will automatically adjust the blowdown flow rate in the next control cycle to avoid unnecessary energy consumption caused by excessive blowdown.

[0111] Further, the first water quality blowdown control feedback data analysis according to the auxiliary blowdown control operation in step S45 includes the following steps:

[0112] Monitor and process the conductivity of the auxiliary blowdown liquid and the dissolved solids concentration of the continuous blowdown liquid conductivity signal and the continuous blowdown dissolved solids concentration data according to the auxiliary blowdown control operation to obtain the auxiliary blowdown liquid conductivity signal and the auxiliary blowdown dissolved solids concentration data;

[0113] When the auxiliary blowdown liquid conductivity signal is less than the preset continuous blowdown stop conductivity threshold value or the auxiliary blowdown dissolved solids concentration data is less than the preset dissolved solids concentration threshold value, perform blowdown end control processing on the auxiliary blowdown control operation to obtain the first blowdown end control operation, and perform the first water quality blowdown control feedback data analysis on the corresponding auxiliary blowdown liquid conductivity signal and the auxiliary blowdown dissolved solids concentration data through the first blowdown end control operation to generate the first water quality blowdown control feedback data.

[0114] In an embodiment of the present invention, during the execution of the auxiliary sewage discharge control operation, the system first monitors and analyzes the continuous sewage discharge liquid conductivity signal and the dissolved solids concentration data in real time. At this time, the liquid conductivity signal and the dissolved solids concentration data are respectively referred to as the auxiliary sewage discharge liquid conductivity signal and the auxiliary sewage discharge dissolved solids concentration data. The acquisition frequency of these data is usually once per second to ensure that the water quality changes during the sewage discharge operation can be reflected in real time. By monitoring these parameters, the system can accurately judge the effectiveness of the auxiliary sewage discharge control operation. When the auxiliary sewage discharge liquid conductivity signal is lower than the preset continuous sewage discharge end conductivity threshold, or the auxiliary sewage discharge dissolved solids concentration data is lower than the preset dissolved solids concentration threshold, the system considers that the sewage discharge operation has achieved the expected effect, and at this time, the sewage discharge end control process is triggered. Specifically, when the liquid conductivity signal drops to less than 2500 μs / cm (the preset continuous sewage discharge end conductivity threshold) or the dissolved solids concentration is lower than 1500 mg / L (the preset continuous sewage discharge end dissolved solids concentration threshold), the sewage discharge end operation starts. During this process, the opening degree of the sewage discharge valve will gradually decrease until the sewage discharge operation stops. After completing the sewage discharge end control, the system analyzes the first water quality sewage discharge control feedback data of the collected auxiliary sewage discharge liquid conductivity signal and the dissolved solids concentration data. By analyzing these data, the system can evaluate whether the sewage discharge process has effectively achieved the purpose of reducing the dissolved solids concentration in the water quality and adjusting the conductivity, and generate the first water quality sewage discharge control feedback data. This feedback data will be used as a reference for the system to help adjust the water quality sewage discharge strategy in the future to optimize the entire water quality control process. In addition, the first water quality sewage discharge control feedback data is also used to analyze the efficiency and optimization space of the sewage discharge operation. If the system detects that the liquid conductivity or the dissolved solids concentration fails to meet the expected requirements, the system will make corresponding adjustments in the subsequent sewage discharge control strategy, such as increasing the sewage discharge flow or extending the sewage discharge time, so as to ensure that the boiler water quality is always within the best control range.

[0115] This specification provides a water quality control system for a once-through boiler, which is used to execute the water quality control method of the once-through boiler as described above. The water quality control system of the once-through boiler includes:

[0116] A preliminary liquid resistance analysis module, which is used to use the liquid monitoring sensor and the temperature monitoring sensor built in the once-through boiler to monitor and process the liquid perception signal and the temperature perception signal of the once-through boiler, and respectively generate the liquid perception signal and the temperature perception signal; perform preliminary liquid resistance calculation processing according to the liquid perception signal to generate preliminary liquid resistance data;

[0117] A liquid resistance temperature compensation analysis module, which is used to perform liquid resistance correction processing for temperature compensation of the preliminary liquid resistance data based on the temperature perception signal to generate liquid resistance data;

[0118] The once-through boiler feed water analysis module is used to perform the feed water operation of the feed pump of the once-through boiler; according to the feed water operation of the feed pump, it instantaneously analyzes and processes the liquid resistance value data for the liquid conductivity and the dissolved solids concentration, and respectively obtains the instantaneous liquid conductivity signal and the instantaneous dissolved solids concentration data;

[0119] The once-through boiler blowdown control module is used to perform the blowdown control operation of the once-through boiler according to the instantaneous liquid conductivity signal and the instantaneous dissolved solids concentration data; it analyzes the water quality blowdown control feedback data according to the blowdown control operation and generates the water quality blowdown control feedback data.

[0120] Therefore, from any point of view, the embodiments should be regarded as exemplary and non-limiting. The scope of the present invention is defined by the appended claims rather than the above description. Therefore, it is intended to embrace all changes that fall within the meaning and scope of the equivalent elements of the application document within the present invention.

[0121] The above are only specific embodiments of the present invention, enabling those skilled in the art to understand or implement the present invention. Various modifications to these embodiments will be obvious to those skilled in the art. The general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to these embodiments shown herein, but rather to the widest scope consistent with the principles and novel features invented herein.

Claims

1. A water quality control method for a once-through boiler, characterized in that, It includes the following steps: Step S1: Use the liquid monitoring sensor and temperature monitoring sensor built in the once-through boiler to monitor and process the liquid sensing signal and temperature sensing signal of the once-through boiler, and generate the liquid sensing signal and temperature sensing signal respectively; perform preliminary liquid resistance value calculation processing according to the liquid sensing signal to generate preliminary liquid resistance value data; Step S2: Perform liquid resistance correction processing with temperature compensation on the preliminary liquid resistance value data based on the temperature sensing signal to generate liquid resistance value data; Step S3: Execute the water supply operation of the feed pump of the once-through boiler; perform immediate analysis processing on the liquid resistance value data for the liquid conductivity and dissolved solids concentration according to the water supply operation of the feed pump, and obtain the immediate liquid conductivity signal and immediate dissolved solids concentration data respectively; Step S4: Execute the blowdown control operation of the once-through boiler according to the immediate liquid conductivity signal and immediate dissolved solids concentration data; Perform water quality blowdown control feedback data analysis according to the blowdown control operation to generate water quality blowdown control feedback data; Among them, Step S4 includes the following steps: Among them, the execution of the blowdown control operation of the once-through boiler includes Steps S41 to S46, and the water quality blowdown control feedback data analysis is Step S47; Step S41: When the immediate liquid conductivity signal is not less than the preset continuous blowdown start conductivity threshold and the dissolved solids concentration data is not less than the preset dissolved solids concentration threshold, execute the continuous blowdown control operation of the once-through boiler; Step S42: Perform monitoring processing on the immediate liquid conductivity signal and immediate dissolved solids concentration data for continuous blowdown according to the continuous blowdown control operation to obtain the continuous blowdown liquid conductivity signal and continuous blowdown dissolved solids concentration data; Step S43: Perform time-series trend analysis on the continuous blowdown conductivity signal to generate continuous blowdown conductivity trend data; Step S44: When the continuous blowdown conductivity trend data is in an increasing trend, execute Step S45; or when the continuous blowdown conductivity trend data is in a decreasing trend, execute Step S46; Step S45: Continuously monitor the continuous blowdown liquid conductivity signal until the continuous blowdown liquid conductivity signal is not less than the preset continuous blowdown liquid conductivity threshold: perform auxiliary blowdown control processing on the continuous blowdown control operation to obtain the auxiliary blowdown control operation; perform first water quality blowdown control feedback data analysis according to the auxiliary blowdown control operation to generate first water quality blowdown control feedback data; Step S46: When the continuous blowdown liquid conductivity signal is less than the preset continuous blowdown stop conductivity threshold or the continuous blowdown dissolved solids concentration data is less than the preset dissolved solids concentration threshold: perform blowdown end control processing on the continuous blowdown control operation to obtain the second blowdown end control operation; perform second water quality blowdown control feedback data analysis on the corresponding continuous blowdown liquid conductivity signal and continuous blowdown dissolved solids concentration data through the second blowdown end control operation to generate second water quality blowdown control feedback data; Step S47: Analyze the water quality sewage control feedback data based on the first water quality sewage control feedback data or the second water quality sewage control feedback data to generate the water quality sewage control feedback data.

2. The water quality control method of the once-through boiler according to claim 1, characterized in that, Step S1 includes the following steps: Step S11: Use the liquid monitoring sensor and temperature monitoring sensor built in the once-through boiler to monitor and process the liquid perception signal and temperature perception signal of the once-through boiler, and generate the liquid perception signal and temperature perception signal respectively; Step S12: Perform liquid current detection processing on the liquid perception signal to generate a liquid current signal; Step S13: Perform preliminary liquid resistance value calculation processing based on the liquid current signal to generate preliminary liquid resistance value data.

3. The water quality control method of the once-through boiler according to claim 1, characterized in that, Step S2 includes the following steps: Step S21: Perform temperature electro-variable signal conversion processing on the temperature perception signal to generate a temperature electro-variable signal; analyze the boiler temperature data based on the temperature electro-variable signal to generate boiler temperature data; Step S22: Obtain the historical liquid resistance-thermal correlation data of the once-through boiler; Step S23: Design a correlation influence prediction model for liquid resistance and temperature compensation based on the historical liquid resistance-thermal correlation data of the once-through boiler to generate a liquid resistance temperature compensation correlation model; Step S24: Use the liquid resistance temperature compensation correlation model to analyze the temperature-compensated liquid resistance correction data of the boiler temperature data to generate temperature-compensated liquid resistance correction data; Step S25: Perform temperature-compensated liquid resistance correction processing on the preliminary liquid resistance data through the temperature-compensated liquid resistance correction data to generate liquid resistance data.

4. The water quality control method of the cross-flow boiler according to claim 3, characterized in that, Step S23 includes the following steps: Step S231: Perform liquid sample resistance value division processing based on the historical liquid resistance-thermal correlation data to generate divided liquid sample resistance value data; perform liquid sample resistance value specificity analysis on the divided liquid sample resistance value data to generate liquid sample resistance value specificity data; Step S232: Perform resistance-specific temperature influence coefficient analysis processing on the historical once-through boiler liquid resistance-thermal correlation data through the liquid sample resistance value specificity data to generate a resistance-specific temperature influence coefficient; Step S233: Analyze the non-linear temperature influence characteristics of each specific type of liquid resistance based on the resistance-specific temperature influence coefficient to generate liquid resistance non-linear temperature influence characteristic data; Step S234: Use the liquid resistance non-linear temperature influence characteristic data as the radial basis kernel parameter, and use the support vector machine algorithm and the radial basis kernel parameter to analyze the correlation influence mapping relationship between the liquid resistance and temperature compensation to generate a liquid resistance temperature compensation correlation model.

5. The water quality control method of the cross-flow boiler according to claim 1, characterized in that, Step S3 includes the following steps: Step S31: Perform digital signal conversion processing on the liquid conductivity based on the liquid resistance data to generate a liquid conductivity signal; Step S32: Analyze the dissolved solids concentration based on the liquid conductivity digital signal to generate dissolved solids concentration data; Step S33: Perform the water feeding operation of the once-through boiler feed pump, and instantaneously update and process the liquid conductivity digital signal and the dissolved solids concentration data according to the water feeding operation of the feed pump to obtain an instantaneous liquid conductivity signal and an instantaneous dissolved solids concentration data respectively.

6. The water quality control method of the once-through boiler according to claim 1, characterized in that The continuous blowdown control operation of the once-through boiler described in step S41 includes the following steps: Perform a blowdown demand quantification and evaluation process based on the instantaneous liquid conductivity signal and the instantaneous dissolved solids concentration data to generate blowdown demand quantification and evaluation data; perform an adaptive blowdown throttle orifice adjustment parameter analysis based on the blowdown demand quantification and evaluation data to generate an adaptive blowdown throttle orifice adjustment parameter; perform the continuous blowdown control operation of the once-through boiler based on the adaptive blowdown throttle orifice adjustment parameter.

7. The water quality control method of the cross-flow boiler according to claim 1, characterized in that, The auxiliary blowdown control process for the continuous blowdown control operation described in step S45 to obtain the auxiliary blowdown control operation includes the following steps: Perform a water feeding synchronous stop control on the water feeding operation of the feed pump and maintain the blowdown control on the continuous blowdown control operation; perform an auxiliary blowdown control operation marking based on the water feeding operation of the feed pump with the water feeding synchronous stop control and the continuous blowdown control operation with the blowdown control to obtain the auxiliary blowdown control operation.

8. The water quality control method of the cross-flow boiler according to claim 1, characterized in that The analysis of the first water quality blowdown control feedback data according to the auxiliary blowdown control operation described in step S45 includes the following steps: Perform a monitoring process of the liquid conductivity and the dissolved solids concentration of the auxiliary blowdown on the continuous blowdown liquid conductivity signal and the continuous blowdown dissolved solids concentration data according to the auxiliary blowdown control operation to obtain an auxiliary blowdown liquid conductivity signal and an auxiliary blowdown dissolved solids concentration data; When the auxiliary blowdown liquid conductivity signal is less than a preset continuous blowdown stop conductivity threshold or the auxiliary blowdown dissolved solids concentration data is less than a preset dissolved solids concentration threshold, perform a blowdown end control process on the auxiliary blowdown control operation to obtain a first blowdown end control operation, and generate first water quality blowdown control feedback data by performing a first water quality blowdown control feedback data analysis on the corresponding auxiliary blowdown liquid conductivity signal and the auxiliary blowdown dissolved solids concentration data through the first blowdown end control operation.

9. A water quality control system for a once-through boiler, characterized in that, For performing the water quality control method of the once-through boiler as described in claim 1, the water quality control system of the once-through boiler includes: A preliminary liquid resistance analysis module for using the liquid monitoring sensor and the temperature monitoring sensor built in the once-through boiler to perform a monitoring process on the liquid sensing signal and the temperature sensing signal of the once-through boiler, and generating a liquid sensing signal and a temperature sensing signal respectively; performing a preliminary liquid resistance calculation process based on the liquid sensing signal to generate preliminary liquid resistance data; A liquid resistance temperature compensation analysis module for performing a temperature compensation-based liquid resistance correction process on the preliminary liquid resistance data based on the temperature sensing signal to generate liquid resistance data; A once-through boiler water feeding analysis module for performing the water feeding operation of the once-through boiler feed pump; performing an instantaneous liquid conductivity and dissolved solids concentration analysis process on the liquid resistance data according to the water feeding operation of the feed pump to obtain an instantaneous liquid conductivity signal and an instantaneous dissolved solids concentration data respectively; A once-through boiler blowdown control module is used to perform the blowdown control operation of the once-through boiler according to the instantaneous liquid conductivity signal and the instantaneous dissolved solids concentration data; analyze the water quality blowdown control feedback data according to the blowdown control operation, and generate the water quality blowdown control feedback data.

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