Oxide skin separation and active control method, system, equipment and medium

Abstract

The invention discloses an oxide skin separation and active prevention and treatment method, system, equipment and medium, and belongs to the technical field of oxide skin separation. The method comprises the steps that online monitoring of oxide skin in a steam pipeline is achieved through a magneto-dependent sensor array, and an upper computer calculates the accumulated height of the oxide skin based on a magnetic induction signal; and a critical peeling thickness model related to the attributes of the pipe is constructed. Under the condition that stripping conditions are met, steam temperature, pressure or medium composition parameters are adjusted, and controlled stripping of the oxide skin in a small particle form is achieved; and the formed gas-solid two-phase flow is guided to a pre-separation device and is separated from a filter screen through rotating flow and gravity, oxide skin particles are discharged and collected, and steam flows back or is discharged. The method realizes active intervention and batch discharge of the oxide skin, and reduces the pipe explosion risk and the maintenance cost.

Description

Technical Field

[0001] The present invention relates to the technical field of oxide scale separation, and in particular to an oxide scale separation and active prevention method, system, equipment and medium. Background Art

[0002] In modern supercritical and ultra-supercritical coal-fired power plants, boiler superheater and reheater pipes are exposed to high-temperature, high-pressure steam for extended periods, causing oxide scale to form and accumulate on the metal pipe surfaces. This naturally occurring oxide layer within the pipes is an inevitable process. Without timely intervention, the scale can flake off and flow with the high-speed steam, forming a gas-solid two-phase flow. This can easily accumulate in bends, headers, desuperheaters, and other locations, causing localized blockages, steam flow deviations, and even, in severe cases, boiler tube bursts and other safety incidents, posing a significant threat to the stable operation of the unit.

[0003] Currently, the industry's primary approach to addressing scale issues is passive cleaning, using methods such as regular downtime inspections, pipe cutting and sampling, offline testing, and manual purging. These methods are not only labor-intensive and time-consuming, but also lack real-time and predictive control, suffering from the systemic flaws of "detection lag, sudden spalling, and uncontrollable blockage." Furthermore, some existing online detection technologies rely on temperature sensing, electrical resistance methods, or acoustic emission, which have poor anti-interference capabilities and low resolution, making it difficult to accurately quantify scale thickness and failing to meet the demands of precise control and safety prediction.

[0004] On the other hand, even if scale accumulation can be identified, existing systems generally lack effective, controlled exfoliation mechanisms and supporting high-efficiency gas-solid separation equipment. Most purge operations fail to achieve controlled thermal disturbances, resulting in concentrated scale exfoliation and excessively large particles, which can easily induce secondary blockage. Furthermore, traditional bypass separation systems generally have simple structures and low separation efficiency, making them difficult to effectively remove scale particles of varying particle sizes and flow rates.

[0005] Therefore, there is an urgent need for an active prevention and control system that integrates online monitoring of oxide scale, critical spalling judgment, thermal parameter control and efficient pre-separation functions to achieve early identification, precise intervention and dynamic removal of oxide scale risks, thereby ensuring the safe operation of boiler pipelines and reducing maintenance costs. Summary of the Invention

[0006] In view of the above-mentioned problems, the present invention is proposed.

[0007] Therefore, the technical problem solved by the present invention is:

[0008] How to build an active prevention and control method and system that can realize online real-time monitoring of oxide scale in steam pipelines, critical spalling judgment, parameter control of spalling and linkage with efficient gas-solid pre-separation, so as to effectively reduce the risk of oxide scale blockage and improve the safety and economy of unit operation.

[0009] In order to solve the above technical problems, the present invention provides the following technical solutions: a method for separating and actively preventing oxide scale, which comprises:

[0010] A magnetic sensor array arranged on the outer wall of a steam pipe collects magnetic induction intensity signals caused by scale accumulation within the pipe and transmits the signals to a host computer for feature extraction and data processing to obtain information on the cumulative height of scale within the steam pipe. Based on the cumulative scale height information and in combination with the pipe material type and steam operating parameters, a critical spalling thickness model related to the pipe wall material properties is constructed to determine whether the scale currently meets the set critical spalling condition. When the critical spalling condition is determined to have been met, a parameter control operation is executed to adjust at least one of the steam temperature, pressure, or medium composition to create a thermal disturbance condition, thereby promoting the controlled spalling of scale in the form of small particles from the surface of the metal substrate before reaching a dangerous thickness. The steam-solid two-phase flow containing scale particles formed by the spalling is directed to a bypass channel equipped with a pre-separation device. Within the pre-separation device, the scale particles are separated from the steam through the synergistic effects of fluid rotation, gravity settling, and filter filtration. The separated scale is introduced into a collection device through a discharge channel, while the steam portion is returned to the thermal system through an outlet or discharged to a safe path.

[0011] As a preferred solution of the oxide scale separation and active prevention method described in the present invention, the magnetic sensor array includes multiple magnetic sensor channels arranged along the length of the steam pipe, each channel is connected to an independent signal acquisition module, and the collected signal is transmitted to the host computer through the communication interface for data processing.

[0012] As a preferred embodiment of the oxide scale separation and active prevention method described in the present invention, the host computer compares the magnetic induction intensity signal collected by each channel with a preset empty pipe reference signal, extracts the change in magnetic induction intensity, and calculates the accumulated height of the oxide scale at each detection position based on the conversion relationship between the change and the oxide scale thickness.

[0013] As a preferred embodiment of the oxide scale separation and active prevention method described in the present invention, the critical spalling thickness model is constructed based on the oxide scale cumulative height data, the thermal expansion coefficient of the pipeline material, the steam temperature change rate, and the historical oxide scale spalling data, and is used to determine whether the oxide scale reaches a safe thickness threshold for controllable spalling at different operating stages.

[0014] As a preferred embodiment of the oxide scale separation and active prevention method described in the present invention, the controlled peeling process adopts a variable temperature steam purge method, and by controlling the rate of change of steam temperature and introducing non-steady-state disturbance steam, the oxide scale is caused to detach from the tube wall in the form of small particles and multiple peelings.

[0015] As a preferred embodiment of the scale separation and active prevention method of the present invention, the pre-separation device includes a steam-solid two-phase flow inlet, a separation chamber, a filter structure, a scale discharge channel and a steam outlet, which are sequentially connected.

[0016] The vapor-solid two-phase flow inlet is connected to the steam bypass channel and is configured to introduce a steam flow containing oxide scale particles into the separation chamber; the separation chamber is configured to form a rotating flow field in the gas-solid mixed fluid to enhance the movement of particles toward the outer diameter; the filter structure is installed on the rotating path of the separation chamber to block and intercept the oxide scale particles moving radially; the oxide scale discharge channel is located at the bottom of the separation chamber and is connected to the oxide scale collection device to guide the separated oxide scale; the steam outlet is arranged at the top or side wall of the separation chamber to guide the separated steam back to the system or discharge it to a safe path.

[0017] As a preferred solution of the oxide scale separation and active prevention method described in the present invention, the oxide scale discharge channel is sequentially connected to the oxide scale discharge primary door and the secondary door, and the two doors are opened sequentially to release the separated oxide scale particles in batches. A separator connected to the oxide scale collection device is provided downstream of the channel, and the discharge channel and the steam outlet passage are respectively provided with electric isolation valves for controlling the discharge path during system operation.

[0018] Another object of the present invention is to provide an oxide scale separation and active prevention system.

[0019] In order to solve the above technical problems, the present invention provides the following technical solutions: an oxide scale separation and active prevention system, comprising: a magnetic sensor array, arranged on the outer wall of a steam pipe, for collecting magnetic induction intensity signals caused by oxide scale accumulation; a signal acquisition module, respectively connected to a plurality of channels of the magnetic sensor array, for transmitting signals to a host computer; a host computer, configured to receive magnetic induction intensity data from the signal acquisition module, and calculate the cumulative height information of the oxide scale through feature extraction and conversion algorithms; a spalling condition judgment module, for constructing a critical spalling thickness model based on the cumulative height information, pipeline material parameters and operating conditions, and judging whether the spalling condition is Satisfy the spalling triggering conditions; a steam regulating device, used to adjust the steam temperature, pressure or medium composition when it is judged that the spalling conditions are met, so as to control the controlled spalling of the oxide scale; a gas-solid two-phase guiding structure, used to guide the oxide scale-containing steam flow generated by spalling to the pre-separation device; the pre-separation device, comprising: a gas-solid two-phase flow inlet, a separation cavity, a filter structure, a discharge channel and a steam outlet, configured to achieve gas-solid separation based on centrifugal, gravity and filtration effects; an oxide scale collecting device, arranged at the end of the discharge channel, for collecting separated oxide scale particles; a steam path control valve, connected to the steam outlet, for controlling the discharge or reflux of the steam path when the system is in operation.

[0020] The present invention provides a computer device, comprising a memory and a processor, wherein the memory stores a computer program, and is characterized in that when the processor executes the computer program, the steps of the oxide scale separation and active prevention method are implemented.

[0021] The present invention provides a computer-readable storage medium having a computer program stored thereon, characterized in that when the computer program is executed by a processor, the steps of the oxide scale separation and active prevention method are implemented.

[0022] The beneficial effects of the present invention are as follows: by arranging a magnetic sensor array on the outer wall of the steam pipe, a signal of a change in magnetic induction intensity caused by oxide scale accumulation is obtained, and combined with the feature extraction and conversion algorithm of the host computer, the quantitative calculation of the oxide scale accumulation height in the pipe is achieved, thereby avoiding the errors and periodic lags caused by traditional offline pipe cutting detection, and effectively improving the monitoring accuracy and real-time performance.

[0023] By introducing key parameters such as the thermal expansion coefficient of the pipe, the steam temperature change rate, and historical oxide scale peeling data, the present invention constructs a critical peeling thickness model associated with operating conditions. This model can dynamically determine the timing of peeling and avoid the risk of pipe burst caused by excessive oxide scale thickness. At the same time, it supports differentiated control strategies and improves control reliability and engineering adaptability.

[0024] By controlling the steam temperature, pressure or medium composition, thermal disturbance conditions are achieved, allowing the oxide scale to fall off in a controlled manner in small particles and multiple times before reaching a dangerous thickness. This avoids the secondary blockage and operational impact caused by traditional large-scale sudden peeling, and significantly enhances the stability and safety margin of the system.

[0025] The pre-separation device of the present invention combines a rotating flow field, gravity sedimentation and a filter screen filtration mechanism, which can efficiently separate oxide scale particles in a gas-solid two-phase flow, and avoid particle recirculation through a graded discharge and collection structure, thereby achieving stable batch cleaning, and solving the problems of low separation efficiency and simple structure of the existing bypass system.

[0026] Compared with the traditional management model that relies on manual inspection and shutdown for pipe cutting, the present invention achieves a closed-loop response for the entire process through a system-integrated automated control mechanism. While effectively ensuring the safe operation of the thermal system, it significantly reduces the labor cost and shutdown losses of oxide scale cleaning. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0028] Figure 1 An overall flow chart of an oxide scale separation and active prevention method provided by one embodiment of the present invention.

[0029] Figure 2 A flow chart for online measurement of the oxide scale accumulation state in a supercritical boiler tube according to an oxide scale separation and active prevention method provided by one embodiment of the present invention.

[0030] Figure 3 This is a functional diagram of software for online detection of oxide scale accumulation in an oxide scale separation and active prevention method provided by one embodiment of the present invention.

[0031] Figure 4 A flowchart for online detection of oxide scale accumulation in an oxide scale separation and active prevention method provided by one embodiment of the present invention.

[0032] Figure 5 A schematic diagram of an oxide scale bypass separation device for an oxide scale separation and active prevention method provided by one embodiment of the present invention.

[0033] Figure 6 A schematic diagram of an oxide scale bypass separation device for an oxide scale separation and active prevention method provided by one embodiment of the present invention.

[0034] In the figure: 1. Separation device body, 2. Inlet pipe, 3. Outlet pipe, 4. Filter, 5. Oxide scale discharge primary door, 6. Oxide scale discharge secondary door, 7. Oxide scale separator, 8. Hydrophobic filter, 9. Guard plate. DETAILED DESCRIPTION

[0035] To make the above-mentioned objects, features, and advantages of the present invention more clearly understood, the following detailed description of the specific embodiments of the present invention is given in conjunction with the accompanying drawings. It is obvious that the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary persons in this field without creative work should fall within the scope of protection of the present invention.

[0036] Example 1, with reference to Figure 1 , is an embodiment of the present invention, which provides a method for separating and actively preventing oxide scale, comprising:

[0037] Step 1: A magnetic sensor array arranged on the outer wall of the steam pipe is used to collect the magnetic induction intensity signal caused by the accumulation of oxide scale in the pipe, and the signal is transmitted to the host computer for feature extraction and data processing to obtain the accumulated height information of the oxide scale in the steam pipe.

[0038] Step 2: Based on the cumulative height information of the oxide scale, and in combination with the pipe material type and steam operation parameters, a critical spalling thickness model related to the pipe wall material properties is constructed, and it is determined whether the current oxide scale reaches the set critical spalling condition.

[0039] Step 3: When it is determined that the critical spalling condition is reached, a parameter control operation is performed to adjust at least one of the temperature, pressure or medium composition of the steam to form a thermal disturbance condition, thereby promoting the controlled spalling of the oxide scale in the form of small particles from the surface of the metal substrate before reaching a dangerous thickness.

[0040] Step 4: The steam-gas-solid two-phase flow containing oxide scale particles formed by the above-mentioned peeling is guided to a bypass channel equipped with a pre-separation device. In the pre-separation device, the oxide scale particles are separated from the steam through the synergistic effect of fluid rotation, gravity sedimentation and filter filtration.

[0041] Step 5: The separated oxide scale is introduced into the collection device through the discharge channel, and the steam portion is returned to the thermal system through the outlet or discharged to a safe path.

[0042] In step 1, the magnetic sensor array includes multiple magnetic sensor channels arranged along the length of the steam pipe. Each channel is connected to an independent signal acquisition module, and the collected signal is transmitted to the host computer through the communication interface for data processing.

[0043] In step 1, the host computer compares the magnetic induction intensity signal collected by each channel with the preset empty tube reference signal, extracts the change in magnetic induction intensity, and calculates the accumulated height of the oxide scale at each detection position based on the conversion relationship between the change and the oxide scale thickness.

[0044] In step 2, the critical spalling thickness model is constructed based on the oxide scale accumulation height data, the thermal expansion coefficient of the pipeline material, the steam temperature change rate, and the historical oxide scale spalling data, and is used to determine whether the oxide scale reaches a safe thickness threshold for controllable spalling at different operating stages.

[0045] In step 3, the controlled exfoliation process adopts a variable temperature steam purge mode, and by controlling the rate of change of the steam temperature and introducing unsteady-state disturbance steam, the oxide scale is caused to separate from the tube wall in the form of small particles and multiple exfoliations.

[0046] In step 4, the pre-separation device includes a steam-solid two-phase flow inlet, a separation chamber, a filter structure, an oxide scale discharge channel and a steam outlet which are sequentially connected.

[0047] The vapor-solid two-phase flow inlet is connected to the steam bypass channel and is configured to introduce a steam flow containing oxide scale particles into the separation chamber; the separation chamber is configured to form a rotating flow field in the gas-solid mixed fluid to enhance the movement of particles toward the outer diameter; the filter structure is installed on the rotating path of the separation chamber to block and intercept the oxide scale particles moving radially; the oxide scale discharge channel is located at the bottom of the separation chamber and is connected to the oxide scale collection device to guide the separated oxide scale; the steam outlet is arranged at the top or side wall of the separation chamber to guide the separated steam back to the system or discharge it to a safe path.

[0048] In step 5, the oxide scale discharge channel is connected to the oxide scale discharge primary door and the secondary door in sequence. The two doors are opened sequentially to release the separated oxide scale particles in batches. A separator connected to the oxide scale collection device is provided downstream of the channel, and the discharge channel and the steam outlet passage are respectively provided with electric isolation valves for controlling the discharge path during system operation.

[0049] In step 1, in an optional embodiment of the present invention, the magnetic sensor array is constructed using a linear array of Hall elements. The sensor spacing is preset to 20-30 mm based on the pipe diameter and desired resolution. Each sensor channel is connected to the central processing unit via an integrated acquisition circuit. The acquisition system periodically scans the magnetic induction intensity of each channel and smoothes the data to generate an initial magnetic induction map. By using the initial empty pipe baseline map as a comparison template, the system can estimate the trend of local magnetic field changes, providing basic data support for subsequent determination of scale distribution changes.

[0050] In a preferred embodiment of the present invention, the magnetic sensor array includes 48 independent detection channels, which are arranged in the typical fouling-sensitive area of ​​the boiler reheater section. Each sensor channel collects the magnetic induction intensity signal outside the pipe and transmits it to the host computer via a multi-channel data acquisition card. The host computer software platform has functional modules such as raw signal visualization, empty pipe comparison analysis, magnetic induction intensity change calculation, oxide scale height conversion, trend alarm, data archiving and historical query. The system calculates the change in magnetic induction intensity by comparing the current collected value with the reference benchmark under the empty pipe state, and estimates the cumulative height of oxide scale at each monitoring point in combination with a pre-established conversion model. The oxide scale status results are displayed in real time in the form of a graphical interface, support the export of analysis reports and the linkage of alarm threshold strategies, realizing the combination of real-time monitoring and trend prediction.

[0051] The beneficial effects of this preferred technical solution are: through the combination of multi-channel high-density deployment and real-time conversion analysis, the system can accurately perceive the state of oxide scale accumulation without destructive testing. Compared with traditional periodic pipe cutting detection methods, this method is non-contact, highly real-time, high-resolution, and requires minimal human intervention. It can continuously track the dynamic accumulation of oxide scale, identify abnormal growth trends in advance, and provide quantitative decision-making basis for subsequent spalling control and pre-separation operations, thereby reducing the risk of equipment pipe bursts, improving unit operational stability, and significantly saving operation and maintenance costs.

[0052] In step 2, in an optional embodiment of the present invention, the critical spalling thickness model is implemented using a table lookup. The thermal expansion coefficients and scale adhesion strengths corresponding to different pipe materials are categorized, and critical spalling thickness thresholds for multiple temperature-pressure combinations are preset. The host computer compares the current cumulative scale height with the model matching parameters. If the scale thickness approaches or reaches the critical spalling range set in the model, the control logic is triggered to proceed to the next stage of operation. This model can be constructed through manual calibration or experimental pre-setting, making it suitable for rapid engineering deployment.

[0053] In a preferred embodiment of the present invention, the critical spalling thickness model is established by combining historical operating data and experimental parameters, taking the reheater section of the supercritical unit as the research object, and performing statistical regression on the scale formation rate, spalling morphology and adhesion to the metal matrix. The thermal expansion coefficient of the fusion material, the steam temperature rise rate, the tube wall stress distribution and the historical spalling event data are used as input variables to form a dynamic and updateable multivariate discriminant model. During the operation of the model, the system receives the scale height information from step 1 in real time, and introduces the current operating parameters as evaluation conditions. It performs predictive calculations through formulas or neural networks, and outputs the current spalling risk level and the recommended intervention time window. The method is based on the research results of the spalling mechanism of different materials in the briefing book for modeling training, combined with industrial actual verification to ensure the accuracy of the model and engineering applicability.

[0054] The beneficial effects of this preferred technical solution include: by incorporating a multi-parameter dynamic modeling approach into scale management, it overcomes the limitations of traditional empirical judgment and achieves predictable and controllable spalling behavior. This model effectively shortens response time, avoids overly conservative cleaning or insufficient spalling, and enhances the scientific and safe nature of proactive system intervention. Furthermore, the model is scalable, continuously learning from new data to automatically optimize parameters, adapting to a variety of pipeline structures and operating conditions. It possesses high versatility and engineering value, significantly improving the operational economy and stability of thermal systems.

[0055] It should be noted that the critical spalling thickness model is constructed based on the following parameters: the accumulated oxide scale height, which is measured in real time by a magnetic sensor array; the thermal expansion coefficient α of the pipe wall material, which is obtained by looking up the material manual based on material selection or by a high-temperature thermal expansion test; the steam temperature rise rate, which is directly derived from the steam temperature-time curve recorded by the operation control system; the equivalent thermal stress of the pipe wall, which is calculated by finite element simulation or a simplified analytical model, combined with parameters such as material modulus, wall thickness, and temperature difference; and the historical oxide scale spalling data set, including the oxide scale spalling time, particle size, and corresponding temperature and pressure conditions for different pipe sections and different loads in the past, which is derived from the regular inspection and accident record database.

[0056] The model is constructed using multivariate nonlinear regression fitting or shallow neural network training, so that when the system receives the current steam parameters and scale height in real time, it can calculate whether the current scale is close to the critical or optimal peeling range and give intervention suggestions.

[0057] In step 3, in an optional embodiment of the present invention, the controlled exfoliation operation utilizes a timed variable temperature purge strategy. This involves periodically adjusting the steam pressure regulating device during normal load operation to briefly raise the steam temperature to a preset range (e.g., 10°C to 20°C above the normal operating temperature), maintaining the temperature for a set duration, and then returning to normal, thereby achieving a rhythmic perturbation of the steam temperature. This process leverages thermal interaction between the steam and the pipe wall to induce thermal stress differences in the oxide scale, thereby causing the oxide scale to flake off in small particles before reaching its maximum thickness.

[0058] In a preferred embodiment of the present invention, the system uses real-time monitoring of the scale's accumulated height to determine whether it approaches the threshold conditions set by the spalling model. Once the trigger condition is met, the system automatically executes a variable-temperature steam purge sequence. By adjusting the steam valve group to achieve a temperature rise rate of 5°C / min to 15°C / min, it introduces an unsteady steam flow with a temperature disturbance amplitude of ±10°C, creating a periodic stress field within the thermally disturbed zone within the tube. This disturbance exploits the mismatch in thermal expansion coefficients between the scale and the metal substrate, forming microcracks at the scale's attachment interface and inducing a granular exfoliation process, effectively achieving controlled, active scale shedding.

[0059] The beneficial effects of this preferred technical solution include: through a disturbance control strategy triggered by monitoring data, the scale removal process is quantified, predictable, and controllable, avoiding pipe blockage and system impact caused by large-scale scale removal, and improving the safety and stability of system operation. Furthermore, this solution is faster and more automated than traditional manual cleaning methods, helping to extend the service life of thermal equipment and significantly reducing maintenance costs.

[0060] In step 4, in an optional embodiment of the present invention, the gas-solid two-phase flow formed by the steam after the oxide scale is exfoliated is directed through a drainage pipe into a bypass system located outside the main pipeline. This bypass system includes a pre-separation device with a rotating cylindrical structure. The cylinder cavity has an inlet arranged tangentially. Steam carrying oxide scale particles enters the cylinder cavity, forming a spiral upward flow. The fluid is filtered by multiple layers of filter screens installed on the inner wall of the rotating path to classify the particles by particle size. Coarse particles settle to the bottom due to gravity and centrifugal forces and are then directed to a collection tank through a discharge channel. Fine particles undergo secondary separation in subsequent filters.

[0061] In a preferred embodiment of the present invention, a pre-separation device is provided at the bypass of the steam pipe, and the device includes a steam-solid two-phase flow inlet, a separation chamber, a filter structure, an oxide scale discharge channel and a steam outlet that are connected in sequence. The steam containing oxide scale particles flows through the inlet into the separation chamber, and a spiral guide structure is designed inside the chamber to form a stable rotating flow field, so that the particles are deflected toward the inner wall of the chamber under the action of centrifugal force; a precision filter structure is arranged at the bottom of the chamber to further intercept tiny particles; after the particles converge, they are discharged through the discharge channel and enter the collector; and the steam is discharged or refluxed into the system at the steam outlet on the upper part or side wall of the chamber. The various components are connected and sealed, have high temperature and pressure resistance capabilities, and are suitable for industrial operating environments.

[0062] The beneficial effects of this preferred technical solution are: the pre-separation device synergistically improves the gas-solid separation efficiency through fluid mechanics and structural design, effectively avoids the blockage of the main system by oxide scale, and improves the recovery rate of particles after peeling; at the same time, bypass guidance and independent discharge mechanisms are set to ensure the stable operation of the main steam path, reduce system resistance and thermal efficiency loss, and realize continuous online separation without interruption of equipment operation, which significantly improves the maintainability and operation safety of the system.

[0063] In step 5, in an optional embodiment of the present invention, the separated scale particles are discharged through a discharge channel at the bottom of the separation chamber. A conventional collection tank is located downstream of the discharge channel for temporary storage of the scale particles. A mechanical one-way check valve and a pneumatic control valve are installed in the channel to ensure unidirectional flow and safety isolation during the discharge process. A bypass valve is installed on the steam side of the system. When the collection tank is full, the valve can be controlled to switch to an alternate path or activate a manual discharge mechanism, achieving periodic ash removal under continuous operation conditions.

[0064] In a preferred embodiment of the present invention, the scale discharge channel is connected to an electrically controlled primary and secondary scale discharge gate, which operate sequentially to achieve intermittent, segmented particle discharge, preventing pressure fluctuations during discharge from impacting system stability. A cyclone collector is located downstream of the channel, providing a sedimentation buffer, overtemperature alarm, and particle density monitoring capabilities, ensuring real-time control of the collector capacity and operating status. The steam outlet and discharge channel are each equipped with an electric isolation valve, which automatically closes or opens according to the system's operating mode to accommodate emission requirements under different operating conditions and ensure the adjustability and safety of the airflow path.

[0065] The beneficial effects of this preferred technical solution are: the structure realizes precise control and efficient collection of the oxide scale emission process, avoiding equipment wear and blockage caused by particle impact; the introduction of graded gating and real-time monitoring enables the system to have adaptive operation adjustment capabilities, improving the intelligence level of the operation process; effectively controls steam reflux and emission paths, enhances the overall stability and safety of the thermal system, and reduces the potential secondary pollution risk caused by particle reflux.

[0066] Example 2, reference Figures 1-6 , which is an embodiment of the present invention, provides a method for separating and actively preventing oxide scale. In order to verify the beneficial effects of the present invention, scientific demonstration is carried out through experiments.

[0067] The method of this embodiment is to construct Figure 1 The three-in-one proactive prevention and control system of online monitoring, controlled exfoliation, and pre-separation, shown here, fundamentally solves the problems of scale shedding and blockage through the synergy of intelligent monitoring, thermodynamic regulation, and efficient separation technologies. This technology abandons the traditional passive management model and prioritizes prevention, supplemented by proactive intervention. Combining multidisciplinary theoretical innovation with engineering practice, it forms a scientific and systematic solution.

[0068] First, by developing an online monitoring system based on magnetic detection, the spectrum of the liquid-solid two-phase flow electrical signal is analyzed in real time to qualitatively determine the oxide scale concentration, providing a basis for adjusting the unit's operating status and steam purging. Second, a critical spalling thickness model is established. By manipulating steam temperature and medium parameters and exploiting the difference in thermal expansion coefficient between the oxide scale and the metal matrix, active spalling of small, repeated, and small particles of oxide scale is achieved, thus avoiding the risk of sudden, large-scale spalling and tube bursts. Furthermore, a multi-tube bundle steam-solid two-phase flow pre-separation device is designed, combining centrifugal force and gravity to separate oxide scale particles, effectively improving oxide scale separation efficiency and reducing the occurrence of blockage accidents. By integrating the full "monitoring-stripping-separation" technology chain, a breakthrough is made in the traditional passive cleaning model, establishing an active spalling mechanism based on thermodynamic regulation. This not only shifts the safety hazard prevention and control threshold forward but also reduces the cost of oxide scale treatment, providing a systematic solution for the safe, efficient, and low-carbon operation of coal-fired units.

[0069] like Figure 2 As shown in the figure, the multi-channel magnetic induction intensity shows that the designed magnetic induction intensity acquisition system includes 48-channel magnetic sensors, which can obtain the magnetic induction intensity distribution on the deposition tube side and the magnetic induction intensity changes caused by the accumulation of oxide scale particles.

[0070] Designed an online monitoring platform for oxide scale accumulation. Figure 3 As shown. The system interface needs to display the original signal of magnetic induction intensity and the change in magnetic induction intensity compared with the empty pipe. The data of the accumulated amount of oxide scale particles is displayed. After the magnetic induction intensity information is processed and calculated, the host computer needs to display the accumulated height of the oxide scale. Historical data query display. The collected magnetic induction intensity signal data must not only be displayed in real time, but also recorded and saved. According to the saved historical data, you can view the needs, and a historical data query function is designed. The software process is as follows Figure 4 shown.

[0071] Based on two-phase flow test research with complementary multiple testing technologies, the numerical simulation method of the movement law of oxide scale particles applicable to the three-dimensional piping layout, structural characteristics and inner wall characteristics of the superheater / reheater is improved, and the critical size for deposition is determined; the relationship between oxide scale peeling, deposition and particle morphology, tube bundle structure, layout method and steam parameters is analyzed, and the critical aerodynamic conditions and key parameters of tube wall properties for blockage are obtained. The deposition distribution law of oxide scale particles in the superheater and reheater tube bundles and the formation mechanism of the blockage phenomenon are systematically revealed, providing a technical basis for the application of controlled oxide scale shedding and online separation technology.

[0072] Compare and study the oxidation resistance of typical domestic and foreign pipes at different temperatures in air and air + steam environments; study the differences in the physical and chemical properties of the same brand materials at home and abroad, and the mechanisms of oxide scale formation and exfoliation of materials in different heat treatment states, to develop material selection or acceptance standards for superheater and reheater pipes, as well as operating temperature control indicators;

[0073] Research and develop a new variable temperature steam purging process: Based on the investigation of the advantages and disadvantages of traditional steam purging of various units, study the process of variable temperature purging, confirm the applicable conditions of variable temperature steam purging in relevant units, summarize the industrial experimental results and propose a research report on a new variable temperature steam purging process.

[0074] An industrial application experiment was conducted on a supercritical unit, installing a pre-separator in the reheater piping. By adjusting the unit's chemical water conditions and optimizing its operating mode, the superheater / reheater oxide scale peeled off while still relatively thin, carried out by steam disturbances, and captured by the pre-separator. A multi-parameter online oxide scale concentration monitoring device was also installed, and the unit's operating mode was adjusted and optimized based on the test results. Analysis of operational test data over the next 1-2 years optimized these research results, ultimately resulting in the development of key technologies and equipment for online oxide scale monitoring, controlled peeling, and pre-separation.

[0075] Study the effects of particle size distribution, gravity, centrifugal force, rebound effect, etc. of oxide scale particles on separation efficiency; study the effects of separator shape, installation position, and internal structure on the local resistance coefficient, thermal efficiency, pipeline stress, expansion changes, etc. of the thermal system; and develop oxide scale separation equipment.

[0076] In order to achieve effective online separation, the following scheme is adopted: a gas-solid two-phase flow of high concentration scale / steam is taken out from the steam pipeline and enters a scale bypass separation device (such as Figure 5 In the steam bypass system (shown in Figure 1), the gas-solid two-phase flow in the scale bypass separation device is separated by a filter screen using a combination of gravity and centrifugal force to remove scale. The separated scale and hydrophobicity are collected in a scale collector, while the hydrophobicity is discharged through a hydrophobic filter. The separated steam enters the original bypass system. To facilitate the discharge of the separated scale from the system during unit operation, the scale bypass separation device is equipped with electric or start-up isolation valves at the front and rear.

[0077] Before the overhaul of the unit, take measures such as rapid cooling to shut down the unit to control the degree and amount of scale peeling; and confirm the degree of scale accumulation in the superheater or reheater tubes; study the method of separating scale by bypass steam purge, and use the startup bypass separation (flow chart as shown in the figure) Figure 6 Oxide scale accumulated in the superheater or reheater (as shown).

[0078] For example, at a power plant in Anyuan, research data shows that before implementing online scale detection, controlled scale removal, and pre-separation technology, two units underwent six scale inspections within four years of commissioning, each costing 138,000 yuan, for a total of 828,000 yuan. A total of 1,692 pipes were cut and treated during these six inspections, resulting in a total cleaning cost of 405,500 yuan. Therefore, the total cost of these six scale removal operations was 1,233,500 yuan, averaging 308,400 yuan per year after commissioning. However, after implementing online scale detection, controlled scale removal, and pre-separation technology, the proactive removal, online monitoring, and timely treatment of scale-related blockages have significantly reduced the need for treatment. Calculated at an annual cost of 20,000 yuan, including equipment costs, the annual scale removal cost is 70,000 yuan. This represents a 77% reduction in cleaning costs compared to traditional treatment methods. This significant cost savings not only demonstrates the economic benefits of this technology but also provides a more efficient and cost-effective solution for future operations management.

[0079] Taking a power plant in Anyuan as an example, compared with existing technologies, the scale separation method and three-in-one active prevention and control system proposed in this patent have the following advantages:

[0080] This technology achieves real-time monitoring of oxide scale through online detection. This intelligent monitoring provides a strong data basis for the scientific treatment of oxide scale in power plants, reduces manual intervention and errors, reduces maintenance costs, makes unit operation more efficient and reliable, effectively improves the timeliness and removal rate of oxide scale cleaning, and reduces the workload and time of oxide scale cleaning from 12 days before the application of the technology to 2-3 days. The oxide scale removal rate has reached more than 90%, and the pipe blockage rate has dropped by 96%. This key technology has been successfully applied in supercritical units and is suitable for different load conditions and unit types. The modular design of the technical device facilitates installation and maintenance, and can be quickly promoted to existing units and new projects, with wide industry applicability.

[0081] The application of this technology effectively reduces the oxide scale blockage rate. The timely monitoring and cleaning have reduced the oxide scale treatment costs by 55.84%, and reduced the frequency of pipe bursts and unplanned unit shutdowns. It saves the power plant an average of 1.0988 million yuan in start-up and shutdown costs and 32.974 million yuan in production costs each year, as well as non-shutdown grid assessment costs.

[0082] The application of this technology, on the one hand, changes the traditional pipe cutting method into purging, reducing the possibility of accidents, reducing potential safety hazards, ensuring the safety of workers, and improving the safety level; on the other hand, it reduces the number of unplanned shutdowns of units, making the power supply more stable and providing a strong guarantee for the smooth operation of the power system.

[0083] This technology helps improve energy efficiency, reduce the waste of coal and other energy sources, and conserve resources while reducing waste and pollutant emissions. This not only helps protect the environment but also promotes sustainable development.

[0084] Example 3 is an embodiment of the present invention, which provides an oxide scale separation and active prevention system, including:

[0085] A magnetic sensor array is installed on the outer wall of the steam pipe to collect magnetic induction intensity signals caused by scale accumulation;

[0086] A signal acquisition module, connected to the multiple channels of the magnetic sensor array respectively, for transmitting the signal to the host computer;

[0087] The host computer is configured to receive the magnetic induction intensity data from the signal acquisition module and calculate the cumulative height information of the oxide scale through feature extraction and conversion algorithms;

[0088] a spalling condition judgment module, configured to construct a critical spalling thickness model based on the accumulated height information, pipeline material parameters, and operating conditions, and to judge whether spalling trigger conditions are met;

[0089] A steam control device is used to adjust the steam temperature, pressure or medium composition when it is judged that the spalling conditions are met, so as to control the controlled spalling of the oxide scale;

[0090] A gas-solid two-phase guiding structure is used to guide the scale-containing vapor flow generated by exfoliation to a pre-separation device;

[0091] a pre-separation device comprising: a vapor-solid two-phase flow inlet, a separation chamber, a filter structure, a discharge channel and a steam outlet, configured to achieve gas-solid separation based on centrifugal, gravity and filtration effects;

[0092] An oxide scale collection device is provided at the end of the discharge channel for collecting separated oxide scale particles;

[0093] The steam passage control valve is connected to the steam outlet and is used to control the discharge or reflux of the steam passage when the system is in operation.

[0094] This embodiment also provides an electronic device suitable for a method for separating and actively preventing oxide scale, comprising: a memory and a processor; the memory is used to store computer-executable instructions, and the processor is used to execute computer-executable instructions to implement a method for separating and actively preventing oxide scale as proposed in the above embodiment.

[0095] This embodiment also provides a storage medium on which a computer program is stored. When the program is executed by a processor, an oxide scale separation and active prevention method as proposed in the above embodiment is implemented.

[0096] The storage medium proposed in this embodiment and the method for realizing oxide scale separation and active prevention proposed in the above embodiment belong to the same inventive concept. The technical details not fully described in this embodiment can be referred to the above embodiment, and this embodiment has the same beneficial effects as the above embodiment.

[0097] Through the above description of the implementation methods, those skilled in the art can clearly understand that the present invention can be implemented with the help of software and necessary general-purpose hardware, and of course it can also be implemented by hardware, but in many cases the former is a better implementation method. Based on this understanding, the technical solution of the present invention is essentially or the part that contributes to the prior art can be embodied in the form of a software product, and the computer software product can be stored in a computer-readable storage medium, such as a computer's floppy disk, read-only memory (ROM), random access memory (RAM), flash memory (FLASH), hard disk or optical disk, etc., including a number of instructions for enabling a computer device (which can be a personal computer, server, or network device, etc.) to execute the methods of various embodiments of the present invention.

[0098] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A method for separating and actively preventing oxide scale, characterized in that: include, A magnetic sensor array arranged on the outer wall of the steam pipe collects magnetic induction intensity signals caused by the accumulation of oxide scale in the pipe, and transmits the signals to a host computer for feature extraction and data processing to obtain information on the accumulated height of oxide scale in the steam pipe. Based on the accumulated height information of the oxide scale, combined with the pipe material type and steam operation parameters, a critical spalling thickness model related to the pipe wall material properties is constructed, and it is determined whether the current oxide scale reaches the set critical spalling condition; When it is determined that a critical spalling condition is reached, a parameter control operation is performed to adjust at least one of the temperature, pressure or medium composition of the steam to form a thermal disturbance condition, thereby promoting controlled spalling of the oxide scale in the form of small particles from the surface of the metal substrate before reaching a dangerous thickness; The steam-gas-solid two-phase flow containing oxide scale particles formed by the above-mentioned exfoliation is guided to a bypass channel provided with a pre-separation device, and the oxide scale particles are separated from the steam in the pre-separation device through the synergistic effect of fluid rotation, gravity sedimentation and filter filtration; The separated oxide scale is introduced into the collection device through the discharge channel, and the steam part is returned to the thermal system through the outlet or discharged to a safe path.

2. The method for separating and actively preventing oxide scale according to claim 1, wherein: The magnetic sensor array includes multiple magnetic sensor channels arranged along the length of the steam pipe. Each channel is connected to an independent signal acquisition module and transmits the collected signal to the host computer through a communication interface for data processing.

3. The method for separating and actively preventing oxide scale according to claim 2, wherein: The host computer compares the magnetic induction intensity signal collected by each channel with the preset empty pipe reference signal, extracts the change in magnetic induction intensity, and calculates the accumulated height of the oxide scale at each detection position based on the conversion relationship between the change and the oxide scale thickness.

4. The method for separating and actively preventing oxide scale according to claim 3, wherein: The critical spalling thickness model is constructed based on the oxide scale accumulation height data, the thermal expansion coefficient of the pipeline material, the steam temperature change rate, and the historical oxide scale spalling data, and is used to determine whether the oxide scale reaches a safe thickness threshold for controllable spalling at different operating stages.

5. The method for separating and actively preventing oxide scale according to claim 4, wherein: The controlled spalling process adopts a variable temperature steam purge mode, and by controlling the rate of change of steam temperature and introducing non-steady-state disturbance steam, the oxide scale is caused to separate from the tube wall in the form of small particles and multiple spalling.

6. The method for separating and actively preventing oxide scale according to claim 5, wherein: The pre-separation device includes a steam-solid two-phase flow inlet, a separation chamber, a filter structure, an oxide scale discharge channel and a steam outlet which are connected in sequence. The steam-solid two-phase flow inlet is connected to the steam bypass channel and is configured to introduce the steam flow containing oxide scale particles into the separation chamber; The separation chamber is configured to form a rotating flow field in the gas-solid mixed fluid to enhance the movement of particles toward the outer diameter; The filter structure is installed on the rotation path of the separation chamber to block and intercept scale particles moving in the radial direction; The oxide scale discharge channel is located at the bottom of the separation chamber and is connected to the oxide scale collection device for discharging the separated oxide scale; The steam outlet is arranged on the top or side wall of the separation chamber to guide the separated steam to flow back to the system or be discharged to a safe path.

7. The method for separating and actively preventing oxide scale according to claim 6, wherein: The oxide scale discharge channel is connected to the oxide scale discharge primary door and the secondary door in sequence. The two doors are opened sequentially to release the separated oxide scale particles in batches. A separator connected to the oxide scale collection device is provided downstream of the channel, and the discharge channel and the steam outlet passage are respectively provided with electric isolation valves for controlling the discharge path during system operation.

8. An oxide scale separation and active prevention system, using an oxide scale separation and active prevention method according to any one of claims 1 to 7, characterized in that: include: A magnetic sensor array is installed on the outer wall of the steam pipe to collect magnetic induction intensity signals caused by scale accumulation; A signal acquisition module, connected to the multiple channels of the magnetic sensor array respectively, for transmitting the signal to the host computer; The host computer is configured to receive the magnetic induction intensity data from the signal acquisition module and calculate the cumulative height information of the oxide scale through feature extraction and conversion algorithms; a spalling condition judgment module, configured to construct a critical spalling thickness model based on the accumulated height information, pipeline material parameters, and operating conditions, and to judge whether spalling trigger conditions are met; A steam control device is used to adjust the steam temperature, pressure or medium composition when it is judged that the spalling conditions are met, so as to control the controlled spalling of the oxide scale; A gas-solid two-phase guiding structure is used to guide the scale-containing vapor flow generated by exfoliation to a pre-separation device; a pre-separation device comprising: a vapor-solid two-phase flow inlet, a separation chamber, a filter structure, a discharge channel and a steam outlet, configured to achieve gas-solid separation based on centrifugal, gravity and filtration effects; An oxide scale collection device is provided at the end of the discharge channel for collecting separated oxide scale particles; The steam passage control valve is connected to the steam outlet and is used to control the discharge or reflux of the steam passage when the system is in operation.

9. A computer device comprising a memory and a processor, wherein the memory stores a computer program, wherein: When the processor executes the computer program, the steps of the oxide scale separation and active prevention method according to any one of claims 1 to 7 are implemented.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the oxide scale separation and active prevention method according to any one of claims 1 to 7 are implemented.

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