Water vapor system dynamic regulation and control method based on iron corrosion product migration

Abstract

The invention relates to the technical field of water vapor systems, and particularly provides a water vapor system dynamic regulation and control method based on iron corrosion product migration. The method comprises the following steps: performing real-time dynamic monitoring through a distributed sensor to obtain a source of an iron corrosion product; evaluating the corrosion risk degree, and determining a corrosion risk grade; by adopting a differential dynamic regulation and control strategy, the method realizes optimal control on the iron corrosion product of the water vapor system, and ensures safe operation of the boiler under deep peak regulation of the unit.

Description

Technical Field

[0001] This invention relates to the field of water vapor system technology, and in particular to a dynamic control method for water vapor systems based on the migration of iron corrosion products. Background Technology

[0002] With the large-scale grid connection of new energy sources, deep peak-shaving operation of thermal power units has become the norm. However, under low load and variable load conditions, the iron corrosion and corrosion product migration behavior of boiler water-steam systems are significantly aggravated, leading to increased iron content in feedwater, increased scaling and under-deposit corrosion risks in thermal equipment, and seriously affecting the safety and economy of the unit.

[0003] Traditional water and steam quality control methods are mainly based on steady-state operating conditions and rely on fixed-cycle chemical dosing and sampling, making them difficult to adapt to transient corrosion changes under deep peak shaving. Especially when the load fluctuates rapidly, the response of water chemical parameters (such as pH and dissolved oxygen) is not timely, leading to deterioration of water and steam quality and poor unit operating economy. Traditional iron content analysis methods rely on offline sampling and cannot reflect the dynamic characteristics of iron corrosion product migration in real time. While chemical dosing and blowdown operations and adjustments are being adapted to deep peak shaving conditions, differentiated control methods for each stage of peak shaving are still lacking.

[0004] In recent years, some researchers have attempted to mitigate corrosion by optimizing water chemistry conditions (such as dynamic oxygenation and pH adjustment). However, existing sensors are mostly limited to single-parameter detection and lack multi-parameter fusion analysis capabilities; the corrosion window period (a sensitive period of 30-90 minutes after load change) in the water-steam system during peak shaving is not covered by existing methods. Moreover, current studies have not clearly explored the relationship between corrosion product migration and unit load, especially the correlation between the particle size distribution, corrosion degree, and deposition tendency of iron corrosion products, which makes precise control difficult to achieve. Summary of the Invention

[0005] In view of this, the present invention provides a dynamic control method for a water-steam system based on the migration of iron corrosion products, so as to achieve optimized control of iron corrosion products in the water-steam system and ensure the safe operation of the boiler under deep peak shaving of the unit.

[0006] In a first aspect, the present invention provides a method for dynamic control of a water vapor system based on the migration of iron corrosion products, the method comprising: Step 1: Real-time dynamic monitoring using distributed sensors to obtain the source of iron corrosion products; Step 2: Based on Step 1, evaluate the degree of corrosion risk and determine the corrosion risk level; Step 3: Based on Step 2, adopt a differentiated dynamic control strategy.

[0007] Optionally, step 1 includes: Distributed sensors are deployed in the water supply and steam systems to monitor the concentration and size distribution of iron corrosion product particles, as well as pH and dissolved oxygen water quality parameters in real time, so as to understand the migration process of iron corrosion products. The locations for deploying distributed sensors include the deaerator inlet and outlet, the economizer inlet, and the superheater inlet. Online pH meters, dissolved oxygen sensors, and online particle counters are installed at the superheater inlet.

[0008] Optionally, real-time dynamic monitoring includes: Multi-parameter synchronous acquisition: Data is uploaded to the programmable control system via industrial fieldbus; Dynamic threshold alarm: Set upper and lower limit thresholds for pH, dissolved oxygen, and online particle count; trigger an audible and visual alarm when the limits are exceeded. Collaborative analysis of migration pathways: Collaborative analysis of sensor data from different locations to trace the source of iron corrosion products.

[0009] Optionally, step 2 includes: establishing a corrosion-deposition state assessment matrix and converting monitoring parameters into corrosion risk levels. Level I indicates normal: particles smaller than 5μm account for more than 80%; Grade II indicates that particles with a size of 5μm to 10μm account for more than 30%; Level III indicates a warning: Particles with a size of 10μm to 25μm account for more than 20%; Level IV indicates danger: an increase in particles larger than 25 μm.

[0010] Optionally, corrosion intensification points can be determined by the migration of iron corrosion products: Deposition: The number of particles of all sizes decreases; Corrosion: The number of particles of all sizes increases; Significant corrosion: The number of particles of all sizes increases by more than a factor of 1; Coexistence of deposition and corrosion: The number of large-size particles increases, while the number of small-size particles decreases.

[0011] Optionally, step 3 includes: A dynamic correlation model between unit load changes and corrosion behavior was established to analyze the impact of different peak-shaving stages on corrosion and deposition of thermal equipment. Differentiated dynamic control strategies were adopted through deep learning.

[0012] Optionally, differentiated dynamic control strategies include: pre-protective dosing, enhanced wastewater discharge, and dynamic regulation.

[0013] Optionally, it includes: Pre-protective dosing: Adjust the dosage in advance before the load decreases to inhibit the aggravation of corrosion; Enhanced sewage discharge: Optimize the timing and intensity of sewage discharge and increase the frequency by 3 times to reduce sediment accumulation, taking into account the easy deposition of corrosion products during low-load operation; Dynamic control: Automatically adjust the parameters of oxygenation and ammonia addition based on real-time monitoring data to maintain optimal water chemistry conditions.

[0014] In a second aspect, embodiments of the present invention provide a computer-readable storage medium comprising a stored program, wherein, when the program is executed, the device on which the computer-readable storage medium is located executes the dynamic control method for a water vapor system based on the migration of iron corrosion products, as described in the first aspect or any possible implementation thereof.

[0015] Thirdly, embodiments of the present invention provide an electronic device, including: one or more processors; a memory; and one or more computer programs, wherein the one or more computer programs are stored in the memory, and the one or more computer programs include instructions that, when executed by the device, cause the device to perform the dynamic control method for a water vapor system based on the migration of iron corrosion products in the first aspect or any possible implementation of the first aspect.

[0016] The technical solution provided by this invention includes a method that uses distributed sensors for real-time dynamic monitoring to obtain the source of iron corrosion products; evaluates the degree of corrosion risk to determine the corrosion risk level; and adopts a differentiated dynamic control strategy. This method achieves optimized control of iron corrosion products in the water-steam system, ensuring the safe operation of the boiler under deep peak shaving of the unit. Attached Figure Description

[0017] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 A flowchart of a dynamic control method for a water vapor system based on the migration of iron corrosion products provided in an embodiment of the present invention; Figure 2 A bar chart showing the particulate matter detection results of various parts of the water vapor system in the first quarter, provided as an embodiment of the present invention; Figure 3 A bar chart showing the particulate matter detection results of various parts of the water vapor system in the second quarter, provided as an embodiment of the present invention; Figure 4 A bar chart showing the particulate matter detection results of various parts of the water vapor system in the third quarter, provided as an embodiment of the present invention; Figure 5 A graph showing the particulate matter detection results of condensate from the first quarter to the third quarter, provided for an embodiment of the present invention; Figure 6 A schematic diagram illustrating the results of suspended particulate matter content determination in the influent of the pre-filter provided in an embodiment of the present invention; Figure 7 A schematic diagram illustrating the results of suspended particulate matter content determination in the effluent of the pre-filter provided in an embodiment of the present invention; Figure 8 This is a schematic diagram illustrating the measurement results of suspended particulate matter in a water vapor system provided in an embodiment of the present invention. Figure 9 This is a schematic diagram of an electronic device provided in an embodiment of the present invention. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0020] It should be understood that the described embodiments are merely some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0021] The terminology used in the embodiments of this invention is for the purpose of describing particular embodiments only and is not intended to limit the invention. The singular forms “a,” “the,” and “the” used in the embodiments of this invention are also intended to include the plural forms unless the context clearly indicates otherwise.

[0022] It should be understood that the term "and / or" used in this article is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, the character " / " in this article generally indicates that the preceding and following related objects have an "or" relationship.

[0023] Depending on the context, the word "if" as used here can be interpreted as "when," "when," "in response to determination," or "in response to detection." Similarly, depending on the context, the phrase "if determination" or "if detection (of the stated condition or event)" can be interpreted as "when determination," "in response to determination," "when detection (of the stated condition or event)," or "in response to detection (of the stated condition or event)."

[0024] Figure 1 A flowchart of the dynamic control method for a water vapor system based on the migration of iron corrosion products provided in an embodiment of the present invention is shown below. Figure 1 As shown, the method includes: Step 1: Real-time dynamic monitoring using distributed sensors to obtain the source of iron corrosion products.

[0025] In this embodiment of the invention, step 1 includes: Distributed sensors are deployed in the water supply system and steam system (deaerator, economizer, superheater) to monitor the concentration and size distribution of iron corrosion product particles, as well as pH and dissolved oxygen water quality parameters in real time, so as to understand the migration process of iron corrosion products. The locations of the distributed sensors include the deaerator inlet and outlet, the economizer inlet, the superheater inlet, and online pH meters, dissolved oxygen sensors, and online particle counters are installed at the superheater inlet.

[0026] In this embodiment of the invention, real-time dynamic monitoring includes: Multi-parameter synchronous acquisition: Data is uploaded to the programmable control system via industrial fieldbus (such as Modbus RS485 or Modbus RS232 communication protocols); Dynamic threshold alarm: Set upper and lower limit thresholds for pH, dissolved oxygen, and online particle count; trigger an audible and visual alarm when the limits are exceeded. Collaborative analysis of migration pathways: Collaborative analysis of sensor data from different locations to trace the source of iron corrosion products.

[0027] Step 2: Based on Step 1, evaluate the degree of corrosion risk and determine the corrosion risk level.

[0028] In this embodiment of the invention, step 2 includes: establishing a corrosion-deposition state assessment matrix and converting monitoring parameters into corrosion risk levels. Level I indicates normal: particles smaller than 5μm account for more than 80%; Grade II indicates that particles with a size of 5μm to 10μm account for more than 30%; Level III indicates a warning: Particles with a size of 10μm to 25μm account for more than 20%; Level IV indicates danger: an increase in particles larger than 25 μm.

[0029] In this embodiment of the invention, the corrosion intensification point is determined by the migration of iron corrosion products: Deposition: The number of particles of all sizes decreases; Corrosion: The number of particles of all sizes increases; Significant corrosion: The number of particles of all sizes increases by more than a factor of 1; Coexistence of deposition and corrosion: The number of large-size particles increases, while the number of small-size particles decreases.

[0030] Step 3: Based on Step 2, adopt a differentiated dynamic control strategy.

[0031] In this embodiment of the invention, step 3 includes: A dynamic correlation model between unit load changes and corrosion behavior was established to analyze the impact of different peak-shaving stages (such as load reduction, low-load stable operation, and load increase) on corrosion and deposition of thermal equipment. Differentiated dynamic control strategies were adopted through deep learning functions.

[0032] In this embodiment of the invention, the differentiated dynamic control strategy includes: pre-protective dosing, enhanced sewage discharge, and dynamic regulation.

[0033] In this embodiment of the invention, it includes: Pre-protective dosing: Adjust the dosage in advance (e.g., increase the pH buffer concentration) before the load decreases to inhibit the aggravation of corrosion; Enhanced sewage discharge: Optimize the timing and intensity of sewage discharge and increase the frequency by 3 times to reduce sediment accumulation, taking into account the tendency of corrosion products to deposit during low-load operation; Dynamic control: Automatically adjust the parameters of oxygenation and ammonia addition based on real-time monitoring data to maintain optimal water chemistry conditions.

[0034] Example 1 of this invention describes the iron corrosion situation in the water-steam system of a 600MW supercritical once-through boiler unit: Online monitoring was conducted on different water and steam qualities of the 600MW unit. Particulate matter detection results at various points during the water and steam circulation process are as follows: Figures 2 to 4 As shown in Table 1, the corrosion and deposition of iron in each part are as follows.

[0035] Table 1. Corrosion and deposition of iron in various parts of the water vapor system. ; The quarterly changes in the content of iron corrosion products in various parts of the water-steam system indicate that significant corrosion occurred from the reheater outlet to the condensate pump outlet in the second quarter, and the operating cycle of the fine treatment equipment was shortened. By accurately locating the parts of the thermal equipment where corrosion is aggravated, dynamic control methods by adjusting parameters can be adopted.

[0036] Example 2 of this invention: Abnormal adjustment of the condensate polishing system of a 630MW supercritical unit: Problem: The pre-filter is malfunctioning, and the differential pressure is rising extremely rapidly; Problem Diagnosis: Monitoring the inlet and outlet water of the pre-filter: (1) During continuous monitoring of the inlet water of the pre-filter, the maximum value of the suspended particulate matter volume concentration was 28.0 ppb, the minimum value was 0.1 ppb, and the average value was 1.0 ppb; the maximum value was about 28 times the average value. However, since the volume concentration of suspended particulate matter was low in about 80% of the samples, the data of these 80% that are more representative of the normal level of the power plant were analyzed. The average volume concentration of suspended particulate matter was 0.5 ppb, and the maximum value (28.0 ppb) reached 56 times the average value (particulate matter with a frequency of 80%).

[0037] (2) The contribution of suspended particulate matter with a volume concentration less than the average value (average value is 0.5 ppb) to the filter element’s dirt-holding capacity is 17%, but the contribution of suspended particulate matter with a volume concentration greater than the average value to the filter element’s dirt-holding capacity reaches 83%. In other words, the contribution of particulate matter with a volume concentration greater than the average value to the filter element’s dirt-holding capacity is about 5 times that of particulate matter with a volume concentration less than the average value, thus greatly shortening the filter’s operating time. (3) There are six main time periods when suspended particulate matter in the influent of the pre-filter shows a relatively large peak, such as Figure 6 From points A to F, the particle size distribution of the particles at the maximum peak value D was analyzed first, and it was found that there were large suspended particles that were different from the normal size, which lasted for a total of 107 minutes.

[0038] Since the particle size distribution of particulate matter in the normal condensate influent of the power plant is stable (basically below 15μm), when large-diameter (above 25μm) suspended particles appear and the number of small-diameter suspended particles increases significantly, it is inferred that this may be due to the concentrated flushing of flow-accelerated corrosion (FAC) products when the system load fluctuates significantly.

[0039] (4) When the number of suspended particles in the influent increases significantly, the number of suspended particles in the effluent also increases significantly, such as Figure 7 As shown, the significant increase in suspended particulate matter in the filter influent (at point D1 corresponding to the maximum peak time D of the influent) caused instantaneous penetration of the pre-filter, contaminating the internal filter layer. Since the filter layer of the pleated filter element is composed of multiple layers of filter cloth, the conventional backwashing process can only wash away contaminants on the surface of the pleated filter element, but cannot wash away contaminants trapped between the filter cloths, resulting in an excessively rapid increase in the operating pressure differential of the pre-filter.

[0040] (5) The variation of suspended particulate matter in the influent is large, which may result in the failure to obtain the water sample with the worst operating conditions during routine sampling and monitoring of the power plant, while the laboratory water quality monitoring results meet the standards, but in reality the water vapor quality is poor.

[0041] In embodiments of the present invention, such as Figure 8 As shown, the number of suspended particles in the effluent of the pre-filter 1A, the effluent of the mixed bed, the economizer inlet, the deaerator inlet, the deaerator outlet, the main steam, the reheat steam inlet and outlet, the condensate pump outlet, and the filter inlet were continuously monitored. It can be seen that: (1) The number of suspended particles in the high-speed mixed bed effluent is greater than that in the filter effluent. The reason may be that the mixed bed resin decomposes into organic matter; (2) The number of suspended particles in the economizer inlet, the deaerator inlet, the deaerator outlet, and the main steam is comparable to the steam quality of other 600MW units; (3) The number of suspended particles in the reheat steam outlet is more than ten times higher than that in the reheat steam inlet, indicating that the reheat steam section has severe corrosion, resulting in a large number of suspended particles in the condensate of the steam after condensation and the boiler feedwater as the main components.

[0042] This invention uses distributed sensors to collect migration characteristic parameters of iron corrosion products in a water-vapor system in real time, analyzes and quantifies the degree of corrosion risk by using corrosion-deposition state, and adopts synergistic optimization of chemical dosing / discharge to solve the problem of transient corrosion control under deep peak shaving conditions, shortening the corrosion risk response time from the traditional 168 hours (daily weekly inspection) to less than 1 hour.

[0043] The technical solution provided by this invention includes a method that uses distributed sensors for real-time dynamic monitoring to obtain the source of iron corrosion products; evaluates the degree of corrosion risk to determine the corrosion risk level; and adopts a differentiated dynamic control strategy. This method achieves optimized control of iron corrosion products in the water-steam system, ensuring the safe operation of the boiler under deep peak shaving of the unit.

[0044] The various steps in the embodiments of the present invention can be performed by an electronic device. This electronic device includes, but is not limited to, tablet computers, portable PCs, and desktop computers.

[0045] This invention provides a computer-readable storage medium including a stored program, wherein, when the program is running, it controls the electronic device containing the computer-readable storage medium to execute the above-described embodiment of the dynamic control method for water vapor system based on the migration of iron corrosion products.

[0046] Figure 9 A schematic diagram of an electronic device provided in an embodiment of the present invention, such as... Figure 9 As shown, the electronic device 21 includes a processor 211, a memory 212, and a computer program 213 stored in the memory 212 and executable on the processor 211. When the computer program 213 is executed by the processor 211, it implements the dynamic control method of the water vapor system based on the migration of iron corrosion products in the embodiment. To avoid repetition, it will not be described in detail here.

[0047] Electronic device 21 includes, but is not limited to, processor 211 and memory 212. Those skilled in the art will understand that... Figure 9 This is merely an example of electronic device 21 and does not constitute a limitation on electronic device 21. It may include more or fewer components than shown, or combine certain components, or different components. For example, electronic device may also include input / output devices, network access devices, buses, etc.

[0048] The processor 211 may be a Central Processing Unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor may be a microprocessor or any conventional processor.

[0049] The memory 212 can be an internal storage unit of the electronic device 21, such as a hard disk or RAM of the electronic device 21. The memory 212 can also be an external storage device of the electronic device 21, such as a plug-in hard disk, Smart Media Card (SMC), Secure Digital (SD) card, or FlashCard equipped on the electronic device 21. Furthermore, the memory 212 can include both internal and external storage units of the electronic device 21. The memory 212 is used to store computer programs and other programs and data required by network devices. The memory 212 can also be used to temporarily store data that has been output or will be output.

[0050] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0051] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for dynamic control of a water vapor system based on the migration of iron corrosion products, characterized in that, The method includes: Step 1: Real-time dynamic monitoring using distributed sensors to obtain the source of iron corrosion products; Step 2: Based on Step 1, evaluate the degree of corrosion risk and determine the corrosion risk level; Step 3: Based on Step 2, adopt a differentiated dynamic control strategy.

2. The method according to claim 1, characterized in that, Step 1 includes: Distributed sensors are deployed in the water supply and steam systems to monitor the concentration and size distribution of iron corrosion product particles, as well as pH and dissolved oxygen water quality parameters in real time, so as to understand the migration process of iron corrosion products. The locations for deploying distributed sensors include the deaerator inlet and outlet, the economizer inlet, and the superheater inlet. Online pH meters, dissolved oxygen sensors, and online particle counters are installed at the superheater inlet.

3. The method according to claim 2, characterized in that, Real-time dynamic monitoring includes: Multi-parameter synchronous acquisition: Data is uploaded to the programmable control system via industrial fieldbus; Dynamic threshold alarm: Set upper and lower limit thresholds for pH, dissolved oxygen, and online particle count; trigger an audible and visual alarm when the limits are exceeded. Collaborative analysis of migration pathways: Collaborative analysis of sensor data from different locations to trace the source of iron corrosion products.

4. The method according to claim 3, characterized in that, Step 2 includes: establishing a corrosion-deposition state assessment matrix and converting monitoring parameters into corrosion risk levels. Level I indicates normal: particles smaller than 5μm account for more than 80%; Grade II indicates that particles with a size of 5μm to 10μm account for more than 30%; Level III indicates a warning: Particles with a size of 10μm to 25μm account for more than 20%; Level IV indicates danger: an increase in particles larger than 25 μm.

5. The method according to claim 4, characterized in that, Determining corrosion intensification points by the migration of iron corrosion products: Deposition: The number of particles of all sizes decreases; Corrosion: The number of particles of all sizes increases; Significant corrosion: The number of particles of all sizes increases by more than a factor of 1; Coexistence of deposition and corrosion: The number of large-size particles increases, while the number of small-size particles decreases.

6. The method according to claim 5, characterized in that, Step 3 includes: A dynamic correlation model between unit load changes and corrosion behavior was established to analyze the impact of different peak-shaving stages on corrosion and deposition of thermal equipment. Differentiated dynamic control strategies were adopted through deep learning.

7. The method according to claim 6, characterized in that, Differentiated dynamic control strategies include: pre-protective chemical dosing, enhanced wastewater discharge, and dynamic regulation.

8. The method according to claim 7, characterized in that, include: Pre-protective chemical dosing: Adjust the dosage in advance before the load decreases to inhibit the aggravation of corrosion; Enhanced sewage discharge: Optimizes the timing and intensity of sewage discharge, increasing the frequency by 3 times to reduce sediment accumulation, addressing the tendency of corrosion products to deposit during low-load operation; Dynamic control: Automatically adjusts oxygenation and ammonia addition parameters based on real-time monitoring data to maintain optimal water chemistry conditions.

9. A computer-readable storage medium, characterized in that, The computer-readable storage medium includes a stored program, wherein, when the program is executed, it controls the device containing the computer-readable storage medium to perform the dynamic control method for a water vapor system based on the migration of iron corrosion products as described in any one of claims 1 to 8.

10. An electronic device, characterized in that, include: One or more processors; Memory; And one or more computer programs, wherein the one or more computer programs are stored in the memory, and the one or more computer programs include instructions that, when executed by the device, cause the device to perform the dynamic control method for water vapor system based on the migration of iron corrosion products according to any one of claims 1 to 8.

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