A scale separation and active prevention method, system, device and medium

Abstract

The application discloses a kind of oxide skin separation and active prevention and control method, system, equipment and medium, belong to oxide skin separation technical field, including: through magnetic sensor array realizes the on-line monitoring of oxide skin in steam pipeline, host computer is based on magnetic induction signal calculation oxide skin cumulative height, and constructs and the critical peeling thickness model related to pipe material attribute.Under the condition of meeting peeling, steam temperature, pressure or medium composition parameter is adjusted, and oxide skin is controlled to peel off in the form of small particle;The gas-solid two-phase flow formed is guided to a pre-separation device, separated by rotating flow, gravity and filter screen, and oxide skin particles are discharged and collected, and steam is returned or discharged.The application realizes active intervention of oxide skin, batch discharge, reduces the risk of pipe explosion and maintenance cost.

Description

Technical Field

[0001] This invention relates to the field of oxide scale separation technology, specifically to an oxide scale separation and active prevention method, system, equipment and medium. Background Technology

[0002] In modern supercritical and ultra-supercritical coal-fired power generating units, boiler superheater and reheater pipes are constantly exposed to high-temperature, high-pressure steam environments, making it easy for oxide scale to form and accumulate on the metal pipe surfaces. As a naturally occurring oxide layer inside the pipes, the accumulation of oxide scale is unavoidable. Without timely intervention, the scale, after peeling off, will flow at high speed with the steam, forming a gas-solid two-phase flow. This easily accumulates in bends, headers, desuperheaters, and other areas, causing localized blockages, steam flow deviation, and in severe cases, even boiler tube rupture and other safety accidents, posing a significant threat to the stable operation of the unit.

[0003] Currently, the industry's approach to oxide scale issues remains primarily reactive, mainly involving methods such as periodic shutdowns for inspection, pipe cutting for sampling, offline testing, and manual purging. These methods are not only labor-intensive and time-consuming, but also lack real-time and predictive control, exhibiting a systemic flaw: "detection lag – sudden peeling – uncontrollable blockage." Furthermore, existing online detection technologies largely rely on temperature sensing, resistance methods, or acoustic emission, which have poor anti-interference capabilities, low resolution, and difficulty in accurately quantifying oxide scale thickness, failing to meet the demands for precise control and safety prediction.

[0004] On the other hand, even if the state of oxide scale accumulation can be identified, existing systems generally lack effective controlled shedding mechanisms and supporting high-efficiency gas-solid separation devices. Most purging operations fail to achieve controllable thermal disturbance, resulting in concentrated oxide scale shedding and excessively large particles, which easily induces secondary blockage. In addition, traditional bypass separation systems are generally simple in structure and have low separation efficiency, making it difficult to effectively remove oxide scale particles under different 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, so as 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 construct an active prevention and control method and system that can realize online real-time monitoring of oxide scale in steam pipelines, critical peeling judgment, parameter control peeling and efficient gas-solid pre-separation linkage, so as to effectively reduce the risk of oxide scale blockage and improve the safety and economy of unit operation.

[0009] To solve the above-mentioned technical problems, the present invention provides the following technical solution: a method for separating and actively preventing oxide scale, comprising,

[0010] A magnetic sensor array deployed on the outer wall of the steam pipe collects magnetic induction intensity signals caused by oxide scale accumulation inside the pipe. These signals are transmitted to a host computer for feature extraction and data processing to obtain the cumulative height information of the oxide scale inside the steam pipe. Based on this cumulative height information, and combined with the pipe material type and steam operating parameters, a critical spalling thickness model related to the pipe wall material properties is constructed, and it is determined whether the current oxide scale has reached the set critical spalling condition. When the critical spalling condition is reached, parameter control operations are executed, adjusting at least one of the steam temperature, pressure, or medium composition to create thermal disturbance conditions, causing the oxide scale to peel off from the metal substrate surface in small particles before reaching a dangerous thickness. The steam-solid two-phase flow containing oxide scale particles formed by the 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 combined action of fluid rotation, gravity settling, and filter screen filtration. The separated oxide scale is introduced into a collection device through a discharge channel, while the steam portion is returned to the thermal system or discharged to a safe path through the outlet.

[0011] As a preferred embodiment of the oxide scale separation and active prevention method of 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 transmits the acquired signal to the host computer for data processing through a communication interface.

[0012] As a preferred embodiment of the oxide scale separation and active prevention method described in this invention, the host computer compares the magnetic induction intensity signal collected from each channel with the preset empty pipe reference signal, extracts the change in magnetic induction intensity, and calculates the cumulative height of 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 this invention, the critical peeling thickness model is constructed based on the cumulative height data of oxide scale, the thermal expansion coefficient of the pipeline material, the steam temperature change rate, and historical oxide scale peeling data, and is used to determine whether the oxide scale has reached the safe thickness threshold for controlled peeling under different operating stages.

[0014] As a preferred embodiment of the oxide scale separation and active prevention method described in this invention, the controlled peeling process adopts a variable temperature steam purging method, and by controlling the rate of change of steam temperature and introducing unsteady disturbance steam, the oxide scale is detached from the pipe wall in the form of small particles and multiple peelings.

[0015] As a preferred embodiment of the oxide scale separation and active prevention method described in this invention, the pre-separation device includes a vapor-solid two-phase flow inlet, a separation chamber, a filter structure, an oxide 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 the steam flow containing oxide scale particles into the separation chamber. The separation chamber is configured to create a rotating flow field within the gas-solid mixture to enhance the outward movement of the particles. The filter structure is installed on the rotation path of the separation chamber to block and intercept 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 discharge the separated oxide scale. The steam outlet is located 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 embodiment of the oxide scale separation and active prevention method of the present invention, the oxide scale discharge channel is sequentially connected to an oxide scale discharge primary gate and a secondary gate, which are opened sequentially to release the separated oxide scale particles in batches. A separator connected to an oxide scale collection device is provided downstream of the channel, and an electric isolation valve is provided in the discharge channel and the steam outlet passage respectively to control the discharge path during system operation.

[0018] Another objective of this invention is to provide a system for separating and actively preventing oxide scale.

[0019] To solve the above-mentioned technical problems, the present invention provides the following technical solution: a scale separation and active prevention system, comprising: a magnetic sensor array disposed on the outer wall of a steam pipe for collecting magnetic induction intensity signals caused by scale accumulation; a signal acquisition module connected to multiple channels of the magnetic sensor array for transmitting signals to a host computer; a host computer configured to receive the magnetic induction intensity data from the signal acquisition module and calculate the cumulative height information of the scale through feature extraction and conversion algorithms; and a peeling condition judgment module for constructing a critical peeling thickness model based on the cumulative height information, pipe material parameters, and operating conditions, and determining whether... The system includes: a steam control device for adjusting steam temperature, pressure, or medium composition when the peeling conditions are met, to control the controlled peeling of oxide scale; a gas-solid two-phase guiding structure for guiding the oxide scale-containing steam flow generated during peeling to a pre-separation device; a pre-separation device comprising: a gas-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 force, gravity, and filtration; an oxide scale collection device located at the end of the discharge channel for collecting the separated oxide scale particles; and a steam passage control valve connected to the steam outlet for controlling the discharge or recirculation of the steam passage during system operation.

[0020] The present invention provides a computer device, including a memory and a processor, wherein the memory stores a computer program, characterized in that the processor executes the computer program to implement the steps of the aforementioned method for separating and actively preventing oxide scale.

[0021] The present invention provides a computer-readable storage medium having a computer program stored thereon, characterized in that the computer program, when executed by a processor, implements the steps of the aforementioned method for separating and actively preventing oxide scale.

[0022] The beneficial effects of this invention are as follows: by arranging a magnetic sensor array on the outer wall of the steam pipe, the change signal of 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 accumulated height of oxide scale in the pipe is realized, avoiding the errors and periodic lag caused by traditional offline pipe cutting detection, and effectively improving the monitoring accuracy and real-time performance.

[0023] This invention introduces key parameters such as the thermal expansion coefficient of pipe, steam temperature change rate, and historical oxide scale peeling data to construct a critical peeling thickness model related to operating conditions. This model can dynamically determine the timing of peeling, avoid the risk of pipe bursting caused by excessive oxide scale, and support differentiated control strategies, thereby improving the reliability and engineering adaptability of the control.

[0024] By controlling the steam temperature, pressure, or medium composition, thermal disturbance conditions are achieved, allowing the oxide scale to detach in controlled, multiple small particles before reaching a dangerous thickness. This avoids the secondary blockage and operational shocks caused by traditional large-area sudden peeling, significantly enhancing the system's stability and safety boundaries.

[0025] The pre-separation device of the present invention combines a rotating flow field, gravity settling and filter screen filtration mechanism, which can efficiently separate oxide scale particles in a gas-solid two-phase flow. It also avoids particle reflow through a graded discharge and collection structure, and achieves stable batch cleaning, thus solving the problems of low separation efficiency and simple structure of existing bypass systems.

[0026] Compared to the traditional treatment model that relies on manual inspection and shutdown for pipe cutting, this invention achieves a closed-loop response throughout 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 costs and downtime losses associated with oxide scale cleaning. Attached Figure Description

[0027] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying 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.

[0028] Figure 1 This is an overall flowchart of a method for separating and actively preventing oxide scale, provided as an embodiment of the present invention.

[0029] Figure 2 This is a flowchart illustrating the online measurement of oxide scale accumulation in supercritical boiler tubes, as provided in one embodiment of the present invention, for an oxide scale separation and active prevention method.

[0030] Figure 3 This is a functional diagram of online detection software for oxide scale accumulation in an embodiment of the present invention, which provides a method for separating and actively preventing oxide scale.

[0031] Figure 4 This is a flowchart illustrating the online detection process for the cumulative amount of oxide scale in an embodiment of the present invention, which provides a method for separating and actively preventing oxide scale.

[0032] Figure 5 This is a schematic diagram of an oxide scale bypass separation device provided in an embodiment of the present invention for an oxide scale separation and active prevention method.

[0033] Figure 6 This is a schematic diagram of an oxide scale bypass separation device provided in an embodiment of the present invention for an oxide scale separation and active prevention method.

[0034] In the diagram: 1. Separator body, 2. Inlet pipe, 3. Outlet pipe, 4. Filter screen, 5. Primary oxide scale discharge valve, 6. Secondary oxide scale discharge valve, 7. Oxide scale separator, 8. Hydrophobic filter, 9. Protective plate. Detailed Implementation

[0035] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the protection scope of the present invention.

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

[0037] Step 1: By using a magnetic sensor array arranged on the outer wall of the steam pipe, the magnetic induction intensity signal caused by the accumulation of oxide scale inside the pipe is collected, and the signal is transmitted to the host computer for feature extraction and data processing to obtain the cumulative height information of oxide scale inside the steam pipe.

[0038] Step 2: Based on the accumulated height information of the oxide scale, and combined with the pipe material type and steam operation parameters, construct a critical spalling thickness model related to the pipe wall material properties, and determine whether the current oxide scale has reached the set critical spalling condition.

[0039] Step 3: When the critical peeling condition is determined to be reached, execute parameter control operation to adjust at least one of the steam temperature, pressure or medium composition to create thermal disturbance conditions, so that the oxide scale is peeled off from the metal substrate surface in the form of small particles before the dangerous thickness is reached.

[0040] Step 4: Guide the steam-solid two-phase flow containing oxide scale particles formed by the above peeling to the 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 settling and filter screen filtration.

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

[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 transmits the acquired signals to a host computer for data processing via a communication interface.

[0043] In step 1, the host computer compares the magnetic induction intensity signals collected by each channel with the preset empty tube reference signal, extracts the change in magnetic induction intensity, and calculates the cumulative height of 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 peeling thickness model is constructed based on the cumulative height data of oxide scale, the thermal expansion coefficient of the pipe material, the steam temperature change rate, and historical peeling data of oxide scale, and is used to determine whether the oxide scale has reached the safe thickness threshold for controlled peeling under different operating stages.

[0045] In step 3, the controlled peeling process adopts a variable temperature steam purging method, and by controlling the rate of change of steam temperature and introducing unsteady disturbance steam, the oxide scale is detached from the pipe wall in the form of small particles and multiple peelings.

[0046] In step 4, the pre-separation device includes a vapor-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 the steam flow containing oxide scale particles into the separation chamber. The separation chamber is configured to create a rotating flow field within the gas-solid mixture to enhance the outward movement of the particles. The filter structure is installed on the rotation path of the separation chamber to block and intercept 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 discharge the separated oxide scale. The steam outlet is located 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 scale discharge channel is connected in sequence to a primary scale discharge gate and a secondary scale discharge gate. The two gates are opened sequentially to release the separated scale particles in batches. A separator connected to the scale collection device is installed downstream of the channel, and an electric isolation valve is installed in both the discharge channel and the steam outlet passage to control 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 generates an initial magnetic induction spectrum after data smoothing. By setting an initial empty pipe baseline spectrum as a comparison template, the system can estimate the local magnetic field change trend, providing basic data support for subsequent determination of oxide scale distribution changes.

[0050] In a preferred embodiment of the present invention, the magnetic sensor array comprises 48 independent detection channels, deployed in typical fouling-sensitive areas of the boiler reheater section. Each sensor channel collects the magnetic induction intensity signal outside the tube 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 tube 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 a reference benchmark under empty tube conditions, and estimates the cumulative height of oxide scale at each monitoring point by combining it with a pre-established conversion model. The oxide scale status results are displayed in real time in a graphical interface, supporting the export of analysis reports and linkage with alarm threshold strategies, realizing a combination of real-time monitoring and trend prediction.

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

[0052] In step 2, in an optional embodiment of the present invention, the critical peeling thickness model is implemented by a lookup table, classifying the thermal expansion coefficients and oxide scale adhesion strength corresponding to different pipe materials, and pre-setting multiple sets of critical peeling thickness thresholds under temperature-pressure combinations. The host computer compares the current cumulative height of the oxide scale with the model matching parameters. If the oxide scale thickness is close to or reaches the critical peeling range set in the model, the control logic is triggered to enter the next stage of operation. This model can be constructed through manual calibration or experimental pre-setting, and is 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 a supercritical unit as the research object, statistical regression is performed on the formation rate, spalling morphology, and adhesion to the metal matrix of the oxide scale. The model incorporates the material's thermal expansion coefficient, steam temperature rise rate, pipe wall stress distribution, and historical spalling event data as input variables to form a dynamically updatable multivariate discriminant model. During model operation, the system receives the oxide scale height information from step 1 in real time and incorporates current operating parameters as evaluation conditions. Predictive calculations are performed using formulas or neural networks to output the current spalling risk level and recommended intervention time window. The method is based on the research results on spalling mechanisms of different materials in the disclosure document for model training, and is further validated in industrial practice to ensure the model's accuracy and engineering applicability.

[0054] The beneficial effects of this preferred technical solution are as follows: By introducing a multi-parameter dynamic modeling method into scale management, the limitations of traditional experience-based judgment are overcome, enabling predictable and controllable scaling behavior. This model effectively shortens response time, avoids overly conservative cleaning or insufficient scaling, and improves the scientific rigor and safety of proactive system intervention. Simultaneously, the model is scalable, continuously learning from new data to automatically optimize parameters, adapting to various pipeline structures and operating conditions. It possesses high versatility and engineering transfer value, significantly improving the operational economy and stability of the thermal system.

[0055] It should be noted that the critical spalling thickness model is constructed based on the following parameters: cumulative oxide scale height, measured in real time by a magnetic sensor array; thermal expansion coefficient α of the pipe wall material, obtained from the material handbook or through high-temperature thermal expansion tests; steam temperature rise rate, obtained by direct differentiation of the steam temperature-time curve recorded by the operation control system; equivalent thermal stress of the pipe wall, calculated by finite element simulation or simplified analytical model, combined with parameters such as material modulus, wall thickness, and temperature difference; and historical oxide scale spalling dataset, including oxide scale spalling time, particle size, and corresponding temperature and pressure conditions under different pipe sections and loads, derived from the periodic inspection and accident record database.

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

[0057] In step 3, in an optional embodiment of the present invention, the controlled peeling operation employs a timed variable-temperature purging strategy. That is, during normal load operation, the steam temperature is periodically increased to a preset range (e.g., 10°C to 20°C higher than the normal operating temperature) by adjusting the steam pressure regulating device, maintained for a set duration, and then returned to normal, thus achieving rhythmic fluctuations in the steam temperature. This process utilizes the thermal interaction between steam and the pipe wall to induce differences in the thermal stress of the oxide scale, thereby prompting the oxide scale to peel off in small particles before reaching its maximum thickness.

[0058] In a preferred embodiment of the present invention, the system determines whether the accumulated height of the oxide scale, obtained through real-time monitoring, is close to the threshold condition set by the peeling model. Once the trigger condition is met, the system automatically executes a variable-temperature steam purging procedure, adjusting the steam valve group to achieve a temperature rise rate of 5°C / min to 15°C / min, introducing an unsteady steam flow with a temperature disturbance amplitude of ±10°C, thereby creating a periodic stress field in the thermal disturbance zone inside the pipe. This disturbance fully utilizes the mismatch in thermal expansion coefficients between the oxide scale and the metal substrate, forming microcracks at the oxide scale adhesion interface and inducing a granular peeling process, effectively achieving controlled and active oxide scale removal.

[0059] The beneficial effects of this preferred technical solution are as follows: By employing a disturbance control strategy triggered by monitoring data, the oxide scale peeling process is quantified, predictable, and controllable, avoiding pipe blockage or system impact problems caused by large-area peeling, thus improving the safety and stability of system operation. Furthermore, this solution offers faster response and a higher level of automation compared to traditional manual cleaning methods, helping to extend the service life of thermal equipment and significantly reduce maintenance costs.

[0060] In step 4, in an optional embodiment of the present invention, the gas-solid two-phase flow formed by the oxide scale after peeling off and the steam is introduced into a bypass system located outside the main pipeline through a diversion pipe. This bypass system is equipped with a pre-separation device with a rotating cylindrical structure. The inner cavity of the cylinder has an inlet along the tangential direction. After the steam carrying the oxide scale particles enters, it forms a spiral upward flow inside. The fluid is filtered by particle size classification through a multi-layer filter screen set on the inner wall of the rotating path. Coarse particles are deposited to the bottom under gravity and centrifugal force and are introduced into a collection tank through the discharge channel. Fine particles undergo secondary separation in a subsequent filter screen.

[0061] In a preferred embodiment of the invention, a pre-separation device is installed at the steam pipeline bypass. This device includes a steam-solid two-phase flow inlet, a separation chamber, a filter structure, an oxide scale discharge channel, and a steam outlet connected in sequence. Steam containing oxide scale particles enters the separation chamber through the inlet. A spiral flow guiding structure is designed inside the chamber to form a stable rotating flow field, causing the particles to be deflected towards the inner wall of the chamber by centrifugal force. A precision filter structure is arranged at the bottom of the chamber to further intercept small particles. After the particles converge, they are discharged through the discharge channel and enter a collector. Steam is discharged or returned to the system through the steam outlet on the upper part or side wall of the chamber. All components are sealed and have high-temperature and pressure resistance capabilities, making them suitable for industrial operating environments.

[0062] The beneficial effects of this preferred technical solution are as follows: the pre-separation device improves the gas-solid separation efficiency through the synergistic effect of fluid mechanics and structural design, effectively avoids oxide scale clogging the main system, and improves the recovery rate of the stripped particles; at the same time, the bypass guidance and independent discharge mechanism ensures the stable operation of the main steam passage, reduces system resistance and thermal efficiency loss, and realizes continuous online separation without interruption of equipment operation, significantly improving the maintainability and operational safety of the system.

[0063] In step 5, in an optional embodiment of the invention, the separated oxide scale particles are discharged through a discharge channel at the bottom of the separation chamber. A standard collection box structure is provided downstream of the discharge channel for temporary storage of oxide scale. The channel is equipped with a mechanical one-way check valve and a pneumatic control valve to ensure unidirectional flow and safety isolation during the discharge process. The system is equipped with a bypass valve on the steam side. When the collection box is full, the system can switch to a backup path or activate a manual discharge mechanism to achieve periodic ash removal under continuous operation conditions.

[0064] In a preferred embodiment of the invention, the scale discharge channel is sequentially connected to an electrically controlled primary and secondary scale discharge gate. The two gates operate sequentially to achieve intermittent, segmented particle discharge, avoiding the impact of instantaneous pressure fluctuations on system stability. A cyclone separator collector is installed downstream of the channel, featuring settling buffering capabilities, over-temperature alarms, and particle density monitoring to ensure real-time controllability of the collector's capacity and operating status. The steam outlet and discharge channel are each equipped with electrically operated isolation valves, which automatically close or open according to the system's operating mode to adapt to different operating conditions and ensure the adjustability and safety of the airflow path.

[0065] The beneficial effects of this preferred technical solution are as follows: 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 and adjustment capabilities, improving the level of intelligence in the operation process; it effectively controls the steam recirculation and emission path, enhances the overall stability and safety of the thermal system, and reduces the potential secondary pollution risk caused by particle recirculation.

[0066] Example 2, refer to Figures 1-6 This invention provides a method for separating and actively preventing oxide scale, and scientific demonstration is carried out through experiments to verify the beneficial effects of the invention.

[0067] The method in this embodiment constructs, as follows: Figure 1 The online monitoring-controlled peeling-pre-separation integrated proactive prevention system, as shown, fundamentally solves the problems of oxide scale shedding and blockage through the synergistic effect of intelligent monitoring, thermodynamic regulation, and efficient separation technology. This technology abandons the traditional passive treatment model, prioritizing prevention and supplementing it with 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 peeling thickness model is established. By controlling the steam temperature and medium parameters, and utilizing the difference in thermal expansion coefficients between the oxide scale and the metal matrix, the active peeling of small amounts of small particles of oxide scale is achieved, avoiding the risk of tube rupture caused by large-area sudden peeling. Third, 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 the separation efficiency of oxide scale and reducing the occurrence of blockage accidents. Through the integration of the entire "monitoring-peeling-separation" technology chain, the traditional passive cleaning mode is broken through, and an active peeling mechanism based on thermodynamic control is established. This not only moves the prevention and control of safety hazards 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, the multi-channel magnetic induction intensity display shows that the designed magnetic induction intensity acquisition system contains 48 channels of magnetic sensors, which can acquire the magnetic induction intensity distribution on the deposition tube side and the changes in magnetic induction intensity caused by the accumulation of oxide scale particles.

[0070] An online monitoring platform for oxide scale accumulation was designed, such as... Figure 3 As shown. The system interface needs to display the original magnetic induction intensity signal and the change in magnetic induction intensity compared to when the tube is empty. Data on the accumulated oxide scale particles should be displayed. After processing and calculating the magnetic induction intensity information, the host computer needs to display the accumulated oxide scale height. Historical data query and display are also required. The collected magnetic induction intensity signal data not only needs to be displayed in real time but also needs to be recorded and saved. A historical data query function has been designed to allow viewing of the saved historical data. The software flow is as follows: Figure 4 As shown.

[0071] Based on two-phase flow experimental research using complementary testing techniques, this study improves the numerical simulation method for the movement of oxide scale particles, applicable to the three-dimensional piping layout, structural characteristics, and inner wall features of superheaters / reheaters. It determines the critical size for deposition; analyzes the relationship between oxide scale peeling, deposition, particle morphology, tube bundle structure, layout, and steam parameters; obtains the critical aerodynamic conditions for tube blockage and key parameters of tube wall properties; and systematically reveals the deposition distribution pattern of oxide scale particles within the tube bundles of superheaters and reheaters and the formation mechanism of tube blockage, providing a technical basis for the application of controlled oxide scale removal and online separation technologies.

[0072] Comparative studies were conducted on typical pipe materials at home and abroad to assess their oxidation resistance at different temperatures in air and air + steam environments. The differences in physicochemical properties of the same grade of materials at home and abroad were studied, as well as the formation and peeling mechanisms of oxide scale in materials under different heat treatment states. This led to the development of material selection or acceptance standards and operating temperature control indicators for superheater and reheater pipes.

[0073] Research and development of a new variable-temperature steam purging process: Based on a survey of the advantages and disadvantages of traditional steam purging for various units, this study investigates the variable-temperature purging process, confirms the applicable conditions for variable-temperature steam purging in relevant units, summarizes the results of industrial experiments, and proposes a research report on the new variable-temperature steam purging process.

[0074] Industrial application experiments were conducted using a supercritical (ultra-supercritical) unit as an example. A pre-separator was installed in the reheater pipeline. By adjusting the unit's chemical water conditions and optimizing the operating mode, the oxide scale in the superheater / reheater was sloughed off at a relatively thin state, carried away by steam disturbance, and captured by the pre-separator. Simultaneously, a multi-parameter online oxide scale concentration monitoring device was installed, and the unit's operating mode was adjusted and optimized based on the monitoring results. Operational monitoring data from 1-2 years were analyzed to optimize the above research results, ultimately obtaining key technologies and equipment for online monitoring, controlled sloughing, and pre-separation of oxide scale.

[0075] This study investigates the effects of oxide scale particle size distribution, gravity, centrifugal force, and rebound on separation efficiency; it also studies the effects of separator shape, installation location, and internal structure on the local resistance coefficient, thermal efficiency, pipeline stress, and expansion changes of the thermal system; and it aims to develop an oxide scale separation device.

[0076] To achieve effective online separation, the following scheme is adopted: a high-concentration oxide scale / steam gas-solid two-phase flow is taken from the steam pipeline and enters a device equipped with an oxide scale bypass separator (e.g., Figure 5 In the steam bypass system shown, the gas-solid two-phase flow passes through the scale bypass separator, where scale is separated by a combination of a filter screen, gravity, and centrifugal force. The separated scale and condensate are collected in a scale collector, while the condensate is discharged through a condensate filter. The separated steam then enters the original bypass system. To facilitate the removal of the separated scale from the system during unit operation, the scale bypass separator is equipped with electrically operated or manually operated isolation valves before and after its operation.

[0077] Before the unit overhaul, measures such as rapid cooling were taken to shut down the unit and control the degree and amount of oxide scale peeling; this was confirmed by detecting the degree of oxide scale accumulation inside the superheater or reheater tubes; a method for separating oxide scale by bypass steam purging was studied, utilizing start-up bypass separation (flowchart shown in...). Figure 6 (As shown) Oxide scale accumulated in the superheater or reheater.

[0078] Taking a power plant in Anyuan as an example, according to survey data, before the application of online detection, controlled peeling, and pre-separation technology for oxide scale, the two units underwent six oxide scale inspections within four years of commissioning, with each inspection costing 138,000 yuan, totaling 828,000 yuan. A total of 1,692 pipes were cut and treated during the six inspections, with cleaning costs totaling 405,500 yuan. Therefore, the total cost of oxide scale cleaning for the six inspections was 1,233,500 yuan, averaging 308,400 yuan per year after commissioning. After the application of online detection, controlled peeling, and pre-separation technology for oxide scale, the active peeling of oxide scale and online monitoring and timely treatment significantly reduced the blockage problem caused by oxide scale, essentially eliminating the need for treatment. If calculated at 20,000 yuan per year, plus equipment costs, the annual oxide scale cleaning cost would be 70,000 yuan. This means that compared to traditional methods, the introduction of online detection, controlled peeling, and pre-separation technology for oxide scale reduced cleaning costs by approximately 77%. This significant cost saving not only demonstrates the economic benefits of this technology but also provides a more efficient and economical solution for our future operation and management.

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

[0080] This technology enables real-time monitoring of oxide scale through online detection. This intelligent monitoring provides strong data support for power plants to scientifically handle oxide scale, reducing manual intervention and errors, lowering maintenance costs, and making unit operation more efficient and reliable. It effectively improves the timeliness and removal rate of oxide scale cleaning, reducing the workload and time from 12 days before the technology's application to 2-3 days. The oxide scale removal rate reaches over 90%, and the pipe blockage rate decreases by 96%. This key technology has been successfully applied in ultra-supercritical units and is adaptable to different load conditions and unit types. The modular design of the technology facilitates installation and maintenance, and can be quickly promoted to existing units and new projects, demonstrating broad industry applicability.

[0081] The application of this technology effectively reduces the rate of oxide scale blockage. The timeliness of monitoring and cleaning reduces oxide scale treatment costs by 55.84%, and reduces the frequency of pipe bursts and unplanned unit shutdowns. On average, it saves power plants RMB 1.0988 million in start-up and shutdown costs and RMB 32.974 million in production costs annually, as well as grid assessment costs for unplanned shutdowns.

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

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

[0084] Example 3 is an embodiment of the present invention, which provides a system for separating and actively preventing oxide scale, comprising:

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

[0086] The signal acquisition module is connected to multiple channels of the magnetic sensor array and is used to transmit signals to the host computer.

[0087] The host computer is 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.

[0088] The spalling condition judgment module is used to construct a critical spalling thickness model based on the accumulated height information, pipe material parameters and operating conditions, and to determine whether the spalling triggering conditions are met.

[0089] Steam control device is used to adjust steam temperature, pressure or medium composition when it is determined that the peeling conditions are met, so as to control the controlled peeling of oxide scale.

[0090] A gas-solid two-phase guiding structure is used to guide the oxide scale-containing vapor stream generated during peeling to the pre-separation device;

[0091] The pre-separation device includes: a vapor-solid two-phase flow inlet, a separation chamber, a filter structure, an exhaust channel, and a steam outlet, configured to achieve gas-solid separation based on centrifugation, gravity, and filtration.

[0092] An oxide scale collection device is installed at the end of the discharge channel to collect the separated oxide scale particles;

[0093] A steam passage control valve, connected to the steam outlet, is used to control the discharge or backflow of steam in the system operating state.

[0094] This embodiment also provides an electronic device applicable to 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 the 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 storing a computer program that, when executed by a processor, implements a method for separating and actively preventing oxide scale as described in the above embodiments.

[0096] The storage medium proposed in this embodiment belongs to the same inventive concept as the method for separating and actively preventing oxide scale proposed in the above embodiments. Technical details not described in detail in this embodiment can be found in the above embodiments, and this embodiment has the same beneficial effects as the above embodiments.

[0097] Based on the above description of the implementation methods, those skilled in the art can clearly understand that the present invention can be implemented using software and necessary general-purpose hardware, and of course, it can also be implemented using hardware, but in many cases the former is a better implementation method. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as a computer floppy disk, read-only memory (ROM), random access memory (RAM), flash memory, hard disk, or optical disk, etc., including several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute the methods of the 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 not to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A method for separating and actively preventing oxide scale, characterized in that: include, By using an array of magnetic sensors arranged on the outer wall of the steam pipe, the magnetic induction intensity signal caused by the accumulation of oxide scale inside the pipe is collected, and the signal is transmitted to the host computer for feature extraction and data processing to obtain the cumulative height information of oxide scale inside the steam pipe. Based on the accumulated height information of the oxide scale, and 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 has reached the set critical spalling condition. When the critical spalling condition is determined to be reached, parameter control operation is performed to adjust at least one of the steam temperature, pressure or medium composition to create thermal disturbance conditions, so that the oxide scale is spalled off from the metal substrate surface in the form of small particles before the dangerous thickness is reached. The vapor-solid two-phase flow containing oxide scale particles formed by 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 vapor through the synergistic effect of fluid rotation, gravity settling and filter screen filtration. The separated oxide scale is introduced into a collection device through an emission channel, while the steam is returned to the thermal system or discharged to a safe path through the outlet. The critical spalling thickness model is constructed based on the cumulative height data of oxide scale, the thermal expansion coefficient of the pipe material, the steam temperature change rate, and historical spalling data of oxide scale, and is used to determine whether the oxide scale has reached the safe thickness threshold for controlled spalling under different operating stages. The controlled peeling process uses variable temperature steam purging, and by controlling the rate of change of steam temperature and introducing unsteady disturbance steam, the oxide scale is detached from the pipe wall in the form of small particles and multiple peelings. The pre-separation device includes a vapor-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 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 create a rotating flow field within the gas-solid mixture to enhance the outward movement of particles; The filter structure is installed on the rotation path of the separation chamber to block and trap 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 for discharging the separated oxide scale. The steam outlet is located at the top or side wall of the separation chamber and is used to guide the separated steam back to the system or to a safe path.

2. The method for separating and actively preventing oxide scale as described in claim 1, characterized in that: 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 acquired signals to a host computer for data processing via a communication interface.

3. The method for separating and actively preventing oxide scale as described in claim 2, characterized in that: The host computer compares the magnetic induction intensity signals collected from each channel with the preset empty pipe reference signal, extracts the change in magnetic induction intensity, and calculates the cumulative height of oxide scale at each detection location based on the conversion relationship between the change and the oxide scale thickness.

4. The method for separating and actively preventing oxide scale as described in claim 3, characterized in that: The oxide scale discharge channel is connected in sequence to an oxide scale discharge primary gate and a secondary gate. The two gates open sequentially to release the separated oxide scale particles in batches. A separator connected to an oxide scale collection device is installed downstream of the channel. The discharge channel and the steam outlet passage are respectively equipped with electric isolation valves to control the discharge path during system operation.

5. A system for separating and actively preventing oxide scale, using the method for separating and actively preventing oxide scale as described in any one of claims 1 to 4, characterized in that, include: A magnetic sensor array is installed on the outer wall of the steam pipe to collect the magnetic induction intensity signal caused by oxide scale accumulation; The signal acquisition module is connected to multiple channels of the magnetic sensor array and is used to transmit signals to the host computer. The host computer is 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. The spalling condition judgment module is used to construct a critical spalling thickness model based on the accumulated height information, pipe material parameters and operating conditions, and to determine whether the spalling triggering conditions are met. Steam control device is used to adjust steam temperature, pressure or medium composition when it is determined that the peeling conditions are met, so as to control the controlled peeling of oxide scale. A gas-solid two-phase guiding structure is used to guide the oxide scale-containing vapor stream generated during peeling to the pre-separation device; The pre-separation device includes: a vapor-solid two-phase flow inlet, a separation chamber, a filter structure, an exhaust channel, and a steam outlet, configured to achieve gas-solid separation based on centrifugation, gravity, and filtration. An oxide scale collection device is installed at the end of the discharge channel to collect the separated oxide scale particles; A steam passage control valve, connected to the steam outlet, is used to control the discharge or backflow of steam in the system operating state.

6. A computer device comprising a memory and a processor, wherein the memory stores a computer program, characterized in that, When the processor executes the computer program, it implements the steps of the oxide scale separation and active prevention method according to any one of claims 1 to 4.

7. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the steps of the oxide scale separation and active prevention method according to any one of claims 1 to 4.

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