Water-cooled wall local deformation early warning system and method based on differential relative deformation acquisition

Abstract

The present application relates to the technical field of boiler operation monitoring, and discloses a water-cooled wall local deformation early warning system and method based on differential relative deformation collection, which comprises field data collection modules, a reference establishment module and an early warning output module connected in sequence; the field data collection module comprises wall temperature collection devices and differential relative deformation collection devices arranged on the water-cooled wall pipe and the outer wall of the membrane fin, and is used for collecting live operation data of the monitoring area; the reference establishment module constructs a water-cooled wall local deformation discrimination reference; and the early warning output module fuses the measured data and the discrimination reference to complete local deformation risk judgment and early warning. The present application synchronously collects wall temperature and differential relative deformation information, takes into account pipe material and fin deformation monitoring, solves the problem of insufficient recognition accuracy of single parameter monitoring, and effectively improves the local deformation risk recognition capability of the water-cooled wall.

Description

Technical Field

[0001] This invention relates to the field of boiler operation monitoring technology, specifically to a water-cooled wall local deformation early warning system and method based on differential relative deformation acquisition. Background Technology

[0002] Water-cooled walls are the core heating surface and pressure-bearing critical components of the boiler furnace. During operation, they must simultaneously withstand multiple factors, including high-temperature radiative heat exchange in the furnace, working fluid pressure within the tubes, steam-water flow disturbances, and tube panel support constraints. During long-term boiler service, factors such as combustion deviation, localized coking, soot blowing disturbances, load fluctuations, changes in support connection status, uneven tube panel splicing stiffness, and abnormal membrane fin connections can easily lead to problems such as uncoordinated local thermal expansion of the water-cooled wall, differences in expansion between adjacent pipes, obstructed stress release in the supports, tube panel warping, and accumulated deformation. These early anomalies usually do not present obvious overheating phenomena and are difficult to detect by visual inspection. However, if they continue to develop, they can lead to localized stress concentration, fin cracking, accelerated tube panel deformation, and tube wall fatigue damage, ultimately causing water-cooled wall leakage and seriously affecting the safety and stability of boiler operation.

[0003] Currently, the mainstream monitoring methods for water-cooled walls mainly include wall temperature detection, stress inversion, thermal expansion monitoring, and regular shutdown maintenance. Existing technologies can monitor the fire-facing wall temperature of the water-cooled wall using temperature measuring components, adapting to the temperature measurement needs under fluctuating furnace heat loads; they can also rely on dedicated stress monitoring devices to collect water-cooled wall depth and temperature data to achieve stress detection; and they can monitor the overall thermal expansion state of the boiler through a three-dimensional expansion detection unit and an acoustic measurement system to determine the overall operating condition of the equipment. The above solutions can effectively monitor wall temperature, stress, and overall expansion state, but they lack dedicated mechanical differential data acquisition and risk warning identification methods for small relative displacements, relative rotations, and local warping trends between local reference positions in key areas of the water-cooled wall, making it impossible to accurately capture early minor deformation anomalies.

[0004] Existing patent CN116481679B proposes a boiler water-cooled wall stress monitoring device on the fire-facing side. This device uses a distance-measuring and temperature-measuring heat collector in conjunction with fiber optic data acquisition to solve the problem of difficult stress detection in the harsh furnace environment. However, the accuracy of this solution is highly dependent on the blind hole placement and construction precision, and is easily affected by local temperature gradients, the thermal conductivity of the heat collector, and installation deviations. It cannot continuously and comprehensively reflect the dynamic development process of local deformation in the water-cooled wall. Furthermore, this solution only focuses on stress data monitoring, making it difficult to distinguish between normal thermal expansion fluctuations and abnormal local deformation trends. It lacks the ability to predict early-stage hidden risks such as poor support, differences in pipe expansion, and local warping of the tube panel, failing to meet the operational and maintenance needs for accurate early warning of early water-cooled wall faults. Summary of the Invention

[0005] In order to overcome the shortcomings of the existing technology, the purpose of this invention is to provide a water-cooled wall local deformation early warning system and method based on differential relative deformation acquisition, so as to solve the technical problem of how to improve the ability to identify local deformation risks of water-cooled walls.

[0006] This invention is achieved through the following technical solution: In a first aspect, the present invention provides a water-cooled wall local deformation early warning system based on differential relative deformation acquisition, including a field data acquisition module, a benchmark establishment module and an early warning output module; The field data acquisition module, benchmark establishment module, and early warning output module are electrically connected in sequence; The on-site data acquisition module is used to collect real-time operational data of key monitoring areas of the water-cooled wall. The benchmark establishment module is used to establish a local deformation discrimination benchmark for the key monitoring area of ​​the water-cooled wall; The early warning output module is used to combine real-time operating data with local deformation discrimination criteria to make early warning and discrimination of local deformation risk in key monitoring areas of water-cooled walls; The on-site data acquisition module includes a wall temperature acquisition device and a differential relative deformation acquisition device; The wall temperature acquisition device and the differential relative deformation acquisition device are both installed on the outer wall of the water-cooled wall monitoring area. The water-cooled wall monitoring area is provided with water-cooled wall tubes and membrane fins. The wall temperature acquisition device and the differential relative deformation acquisition device are both distributed on the water-cooled wall tubes and membrane fins.

[0007] Preferably, the wall temperature acquisition device includes a temperature contact column, a pre-tightening spring, a heat insulation sleeve, a temperature measuring element, and a protective box; The preload spring is sleeved on the outside of the temperature contact post; The heat insulation sleeve is coaxially wrapped around the outer wall of the temperature contact column; The temperature sensing element is embedded and fixed inside the temperature contact column; The protective box sealing cover is located on the outer side of the temperature contact column, the pre-tightening spring and the heat insulation sleeve.

[0008] Furthermore, the bottom end of the temperature contact column abuts against the outer wall of the water-cooled wall tube or the surface of the membrane fin; The protective box is a closed shell structure, and there is no rigid connection between the protective box and the water-cooled wall tubes or membrane fins.

[0009] Preferably, the differential relative deformation acquisition device includes a reference measuring seat, a follower measuring seat, an elongated sliding hole, a low-stiffness elastic bridge, a differential amplification arm, a flexible hinge, and a strain-sensitive beam; The reference measuring seat and the follower measuring seat are fixed at intervals to the surface of the water-cooled wall tube or membrane fin; The low-stiffness elastic bridge is installed between the top of the reference measuring base and the servo measuring base; The differential amplifier arm is hinged to both ends of a low-stiffness elastic bridge via flexible hinges. The differential amplifier arm is fixedly connected to the strain-sensitive beam at its bottom, and a differential strain acquisition element is fixedly installed on the strain-sensitive beam.

[0010] Furthermore, at least one of the reference measuring seat and the follower measuring seat is provided with an elongated sliding hole, which is an elongated adjustable mounting hole structure. The structural stiffness of the low-stiffness elastic cable tray is less than the overall structural stiffness of the water-cooled wall tube panel.

[0011] Furthermore, the reference measuring seat and the follow-up measuring seat can be arranged in any one of the following positions: two positions along the same water-cooled wall tube, corresponding positions of adjacent water-cooled wall tubes, positions on both sides of the membrane fin, positions on both sides of the tube-screen splicing structure, and positions on both sides of the support connector.

[0012] Furthermore, the benchmark establishment module has built-in storage of differential relative deformation discrimination benchmark and temperature change discrimination benchmark. The differential relative deformation discrimination benchmark and temperature change discrimination benchmark are both associated with the operating parameters of the water-cooled wall at different operating stages and different load ranges.

[0013] Secondly, the present invention also provides a method for early warning of local deformation of a water-cooled wall based on differential relative deformation acquisition, which, based on the aforementioned system for early warning of local deformation of a water-cooled wall based on differential relative deformation acquisition, includes the following steps: Wall temperature data of key monitoring areas of water-cooled walls are collected through the wall temperature acquisition device of the on-site data acquisition module, and bending strain data of strain-sensitive beams are collected through the differential relative deformation acquisition device. The benchmark establishment module retrieves wall temperature and bending strain data corresponding to stable operating conditions of water-cooled walls at different operating stages and load ranges, and constructs a local deformation discrimination benchmark for key monitoring areas of water-cooled walls. The early warning output module matches the real-time collected data with the local deformation discrimination benchmark of the corresponding working condition range, and calculates the local deformation early warning index of the key monitoring area of ​​the water-cooled wall. The local deformation early warning index is compared with the preset early warning threshold to complete the risk assessment of local deformation of the water-cooled wall and output the corresponding early warning result.

[0014] Preferably, differential relative deformation data is obtained by converting bending strain data, and the specific conversion formula is as follows:

[0015] in, For the first Each differential relative deformation acquisition device at time The acquired differential relative deformation data is used to characterize the relative displacement, relative rotation angle and local warping trend between two reference positions in the key monitoring area of ​​the corresponding water-cooled wall; For the first In a differential relative deformation acquisition device, the differential strain acquisition element at time... The collected bending strain of the strain-sensitive beam; For the first The initial bending strain of a differential relative deformation acquisition device; For the first The strain differential deformation conversion coefficient of the differential relative deformation acquisition device.

[0016] Preferably, the differential relative deformation acquisition process includes: When relative displacement or relative rotation occurs in the water-cooled wall monitoring area, the reference measuring seat and the follow-up measuring seat form a positional deviation. The positional deviation is transmitted to the differential amplifier arm through the low-stiffness elastic bridge. The differential amplifier arm undergoes adaptive deflection based on the flexible hinge, which in turn drives the strain-sensitive beam to produce bending deformation. The real-time bending strain data of the strain-sensitive beam is collected through the differential strain acquisition element.

[0017] Compared with the prior art, the present invention has the following beneficial technical effects: This invention provides a local deformation early warning system for water-cooled walls based on differential relative deformation acquisition. By building a complete system architecture integrating acquisition, benchmark construction, and risk early warning, it realizes the synchronous acquisition and linkage analysis of water-cooled wall temperature parameters and local differential deformation parameters. It can effectively distinguish between normal thermal expansion fluctuations, load fluctuations, and abnormal local deformation states of water-cooled walls. From the top level of the system, it solves the technical defects of traditional monitoring methods that can only acquire a single parameter and cannot identify local expansion incoordination, and significantly improves the overall identification coverage of early deformation risks in key areas of water-cooled walls.

[0018] Furthermore, through the layered structure of pre-tensioning springs, heat insulation sleeves, and protective boxes, a closed-loop protection and stable temperature measurement layout for the temperature contact column and temperature measuring element are achieved. This structure effectively isolates the temperature measuring components from thermal disturbances of the furnace wall, external radiation, ambient temperature changes, and equipment compression and collisions, ensuring high-precision and high-stability acquisition of wall temperature data in key monitoring areas of the water-cooled wall. This provides accurate basic temperature data support for distinguishing between normal temperature fluctuations and temperature distortions accompanied by abnormal deformation, avoiding misjudgments and omissions of deformation risks caused by distorted temperature measurement data, and helping to improve the accuracy of local deformation risk identification.

[0019] Furthermore, by utilizing the contact installation method of the wall temperature acquisition device and its non-rigid connection with the protective box, the temperature contact column precisely adheres to the outer wall of the water-cooled wall tube or the surface of the membrane fins, ensuring accurate temperature measurement. Simultaneously, the protective box does not form a rigid load-bearing structure with the water-cooled wall and does not participate in deformation transmission. This structural design completely avoids the problems of additional constraints, assembly stress, and interference with the normal thermal expansion of the water-cooled wall caused by traditional external temperature measurement devices. It eliminates the influence of the device's own structure on the deformation state of the monitored area, ensuring that the collected wall temperature data perfectly matches the actual operating state of the water-cooled wall, guaranteeing the authenticity of the linkage analysis between temperature and deformation parameters, and optimizing the accuracy of early identification of minor deformation risks.

[0020] Furthermore, through the assembly, positioning, and connection structure of the differential relative deformation acquisition device, a fixed measurement span is formed by the reference measuring seat and the follower measuring seat. Relying on the linkage mechanical structure of the low-stiffness elastic bridge, differential amplification arm, flexible hinge, and strain-sensitive beam, the mechanical conversion and acquisition of relative deformation at the two reference positions is realized. Compared with the traditional single-point strain acquisition method, this structure abandons the reliance on single-point surface strain and back-calculation of complex structural models. It directly converts the small relative displacement, relative rotation angle, and local warping of the two reference positions of the water-cooled wall into the quantified bending strain signal of the strain-sensitive beam. It can accurately capture early hidden defects such as local expansion incoordination, tube screen warping, and constraint stagnation that cannot be identified by single-point monitoring methods, fundamentally improving the ability to identify the risk of local small deformation of the water-cooled wall from the hardware structure level.

[0021] Furthermore, by utilizing the adjustable mounting structure with its elongated sliding holes and the stiffness characteristics of its low-stiffness elastic cable tray, the adjustable mounting structure can accommodate assembly errors such as deviations in water-cooled wall tube diameter, weld height deviations, and unevenness on the tube panel surface. This effectively reduces the interference of assembly deviations on initial strain data, ensuring equipment installation accuracy and the stability of the acquisition baseline. Simultaneously, the low-stiffness elastic cable tray has a stiffness lower than that of the water-cooled wall tube panel, serving only as a force-transmitting structure without generating additional constraints. It does not restrict the normal thermal expansion of the water-cooled wall or generate additional monitoring stress, ensuring a sensitive response to minute local deformations while avoiding monitoring distortions caused by the device's own structure, thus achieving accurate differentiation between normal thermal expansion and abnormal deformation.

[0022] Furthermore, through the multi-scenario deployment structure of dual measurement reference bases, it can adapt to the monitoring layout of various key risk areas such as the axial direction of the same water-cooled wall tube, adjacent tubes, membrane fins, tube-panel splicing areas, and support connectors. This structure is adapted to the deformation defect characteristics of different locations of the water-cooled wall, and can specifically collect different types of local abnormal deformations such as restricted axial expansion, differential expansion of adjacent tubes, fin deformation, splicing area misalignment, and support obstruction. It covers weak areas such as furnace corners, tube-panel splicing areas, support connection areas, and historical over-temperature areas that are difficult to cover by traditional inspection and monitoring methods, thus comprehensively expanding the monitoring and identification range of local deformation risks of the water-cooled wall.

[0023] Furthermore, through the dual-benchmark database storage and operating condition matching structure of the benchmark establishment module, a dual discrimination benchmark of temperature and differential deformation is constructed based on stable operating condition data of different operating stages and load ranges. This structure breaks through the limitations of the traditional fixed threshold discrimination method, can adapt to the dynamic operating characteristics of boilers with varying loads and operating conditions, accurately match the normal thermal expansion and temperature fluctuation ranges under different operating conditions, effectively eliminate monitoring interference caused by operating condition fluctuations, accurately screen out abnormal local deformation data that deviates from the normal operating condition benchmark, realize the accurate identification of early hidden deformation risks of water-cooled walls, and significantly improve the reliability of risk identification under complex operating conditions.

[0024] This invention also provides a method for early warning of local deformation of water-cooled walls based on differential relative deformation acquisition. This method relies on a hardware system to achieve a full-process early warning and discrimination mechanism, including simultaneous acquisition of multiple parameters, benchmark construction, index calculation, and threshold comparison. This method integrates independent wall temperature monitoring and deformation monitoring into a unified discrimination logic. By matching and analyzing real-time data with dynamic benchmarks, it replaces the traditional extensive monitoring mode of manual inspection and single-threshold judgment. It can promptly capture the early accumulation trend of small deformations in water-cooled walls, achieving early warning of deformation risks. This provides timely and effective data for boiler operation adjustments, targeted inspections of key areas, and shutdown repair and verification, thus improving the early risk identification and early warning system from a process perspective.

[0025] Furthermore, a precise calibration relationship between bending strain and relative deformation data was established, enabling the accurate conversion of collected strain signals into quantitative deformation data that characterizes relative displacement, relative rotation, and local warping. This quantification method achieves visualization and data-driven determination of localized, invisible, minute deformations in water-cooled walls, solving the problem that traditional monitoring can only qualitatively judge and cannot quantitatively identify minute deformation defects. It can accurately quantify the degree of deformation anomalies, distinguish between minor deformations caused by normal thermal expansion and abnormal cumulative deformation, greatly improving the accuracy and professionalism of local deformation risk identification.

[0026] Furthermore, the complete process of the step-by-step transmission, amplification, and transformation of the dual-reference position deviation was clarified. This acquisition principle specifically responds to asynchronous deformation caused by water-cooled wall support obstruction, uneven heating, asynchronous expansion, and local warping. It has no obvious response to normal thermal expansion that is uniform and synchronous. It can accurately distinguish between the normal thermal expansion behavior of water-cooled walls and abnormal local deformation defects from the deformation mechanism level. It completely solves the technical problems of traditional monitoring methods that easily misjudge normal expansion as faults and cannot identify minor abnormal deformations. It significantly improves the ability to identify early, hidden, and minor deformation risks in key areas of water-cooled walls. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the water-cooled wall local deformation early warning system in an embodiment of the present invention; Figure 2 This is a schematic diagram of the internal structure of the field data acquisition module in an embodiment of the present invention; Figure 3 This is a schematic diagram comparing the system of the present invention with the traditional system in terms of key indicators; Figure 4 This is a schematic diagram comparing the performance improvement of the system of the present invention with that of the traditional system in various key indicators; In the figure: 1. Water-cooled wall tube; 2. Membrane fin; 3. Reference measuring seat; 4. Follow-up measuring seat; 5. Low-stiffness elastic bridge; 6. Differential amplifier arm; 7. Flexible hinge; 8. Strain-sensitive beam; 9. Temperature contact column; 10. Preload spring; 11. Heat insulation sleeve; 12. Protective box; 13. Long oval sliding hole. Detailed Implementation

[0028] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. 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 scope of protection of the present invention.

[0029] The purpose of this invention is to provide a water-cooled wall local deformation early warning system and method based on differential relative deformation acquisition, so as to solve the technical problem of how to improve the ability to identify local deformation risks of water-cooled walls.

[0030] The present invention will now be described in further detail with reference to the accompanying drawings: See Figure 1 In one embodiment of the present invention, a local deformation early warning system for a water-cooled wall based on differential relative deformation acquisition is provided. The system includes a field data acquisition module, a benchmark establishment module, and an early warning output module. The field data acquisition module is used to acquire real-time operating data of the key monitoring area of ​​the water-cooled wall. The benchmark establishment module is used to establish a local deformation discrimination benchmark for the key monitoring area of ​​the water-cooled wall. The early warning output module is used to combine the real-time operating data with the local deformation discrimination benchmark to make an early warning judgment on the risk of local deformation in the key monitoring area of ​​the water-cooled wall.

[0031] like Figure 2As shown, the field data acquisition module includes a wall temperature acquisition device and a differential relative deformation acquisition device; the wall temperature acquisition device includes a temperature contact column 9, a pre-tightening spring 10, a heat insulation sleeve 11, a temperature measuring element, and a protective box 12; the temperature contact column 9 maintains thermally conductive contact with the temperature measuring area under the compression of the pre-tightening spring 10, and the temperature measuring area can be the outer wall of the water-cooled wall tube 1, the root of the membrane fin 2, the fin reinforcing plate, or a thermally conductive contact element set at the temperature measuring position; the temperature measuring element is set inside the temperature contact column 9 and is used to collect data on the corresponding key monitoring points of the water-cooled wall. The wall temperature data of the measurement area; the heat insulation sleeve 11 is set outside the temperature contact column 9 to reduce the influence of temperature rise inside the protective box 12, thermal disturbance of the furnace wall insulation layer, external radiation and changes in ambient temperature on the temperature measurement results, so that the temperature collected by the temperature measuring element is closer to the actual wall temperature of the measurement area; the protective box 12 is set outside the temperature contact column 9, the pre-tightening spring 10 and the heat insulation sleeve 11 to provide dustproof, collision-proof and insulation material compression protection for its internal components, and the protective box 12 does not serve as a force support component of the water-cooled wall and does not participate in the differential relative deformation transmission.

[0032] The differential relative deformation acquisition device includes a reference measuring seat 3, a follower measuring seat 4, an elongated sliding hole 13, a low-stiffness elastic bridge 5, a differential amplification arm 6, a flexible hinge 7, and a strain-sensitive beam 8. The reference measuring seat 3 and the follower measuring seat 4 are respectively fixed at two reference positions within the same key monitoring area of ​​the water-cooled wall, forming a local deformation measurement span between them. The two reference positions can be located at different axial positions of the same water-cooled wall tube 1, corresponding positions of adjacent water-cooled wall tubes 1, positions on both sides of the membrane fins 2, positions on both sides of the tube-screen splicing structure, or positions on both sides of the support connector. At least one of the reference measuring seat 3 and the follower measuring seat 4 is provided with an elongated sliding hole 13, so that the device can be finely adjusted in position according to the deviation of the water-cooled wall tube 1, the deviation of the weld height of the membrane fins 2, the unevenness of the tube-screen surface, and the deviation of the installation posture during installation, and locked after adjustment to reduce the influence of assembly errors on the initial bending strain.

[0033] The low-stiffness elastic cable tray 5 is straddling the reference measuring base 3 and the follow-up measuring base 4, and the low-stiffness elastic cable tray 5 only serves as a force transmission structure for measurement, not as a support structure for the water-cooled wall; the stiffness of the low-stiffness elastic cable tray 5 is lower than the local structural stiffness of the water-cooled wall tube screen, so that it can respond to the small relative deformation between the two reference positions, but will not impose significant additional constraints on the thermal expansion of the water-cooled wall; through this setting, the acquisition device itself can be prevented from restricting the expansion of the water-cooled wall tube screen in the opposite direction, reducing the additional stress and measurement distortion caused by the installation of the device.

[0034] The differential amplification arm 6 is connected to the low-stiffness elastic bridge 5 via a flexible hinge 7. The strain-sensitive beam 8 is connected to the differential amplification arm 6, and a differential strain acquisition element is provided on the strain-sensitive beam 8. The differential strain acquisition element is used to acquire the bending strain of the strain-sensitive beam 8. When the key monitoring area of ​​the water-cooled wall experiences localized uneven heating, poor support release, inconsistent thermal expansion of adjacent tubes, or localized warping of the tube screen during operation, a small relative displacement or relative rotation will occur between the reference measuring seat 3 and the follow-up measuring seat 4. This small relative deformation is transmitted to the differential amplification arm 6 via the low-stiffness elastic bridge 5. Under the guidance of the flexible hinge 7, the differential amplification arm 6 converts it into the bending deformation of the strain-sensitive beam 8. The differential strain acquisition element acquires the bending strain corresponding to the bending deformation and outputs a signal to characterize the local differential relative deformation.

[0035] Specifically, the differential relative deformation acquisition device does not directly use the strain on the surface of a single tube wall as the basis for judging local deformation. Instead, it reflects the local deformation state through the relative movement between two mechanical reference positions. When the two reference positions move synchronously with the uniform thermal expansion of the water-cooled wall as a whole, the relative displacement between them is small, and the output change of the strain-sensitive beam 8 is weak. When one of the reference positions moves asynchronously relative to the other reference position due to support obstruction, local warping, heating differences between adjacent tubes, or tube-screen connection constraints, the differential relative deformation acquisition device can convert this asynchronous movement into a significant change in the bending strain of the strain-sensitive beam 8, thereby identifying local expansion incoordination phenomena that are not easily reflected directly by ordinary wall temperature measuring points or single-point strain measuring points.

[0036] Specifically, the key monitoring areas of the water-cooled wall include locations where local deformation, inconsistent expansion, or abnormal constraint are likely to occur, such as areas near support connections, furnace corners, historical over-temperature areas, tube panel splicing areas, and tube panel deformation-sensitive areas. Among these, areas near support connections are prone to limited thermal expansion release due to insufficient support clearance, poor sliding, or stuck connectors; furnace corners are prone to local torsion or warping due to inconsistent thermal expansion directions of different wall surfaces; historical over-temperature areas are prone to accumulated local deformation due to long-term thermal fatigue, local coking, or heating deviations; tube panel splicing areas are prone to local misalignment due to uneven connection stiffness or residual welding stress; and tube panel deformation-sensitive areas can be determined based on shutdown maintenance records, visual inspection records, wall thickness re-measurement records, or historical alarm records.

[0037] Specifically, the two reference positions can be arranged according to different monitoring purposes. When the two reference positions are located at different axial positions of the same water-cooled wall tube 1, the differential relative deformation acquisition device is mainly used to collect the elongation difference, local bending, or axial expansion restriction trend of a single tube segment along the axial direction. When the two reference positions are located at corresponding positions of adjacent water-cooled wall tubes 1, the differential relative deformation acquisition device is mainly used to collect the lateral misalignment, differential expansion, or local tube screen warping trend between adjacent tubes. When the two reference positions are located on both sides of the membrane fin 2, the differential relative deformation acquisition device is mainly used to collect the deformation inconsistency between the water-cooled wall tubes 1 on both sides of the fin. When the two reference positions are located on both sides of the tube screen splicing structure or on both sides of the support connector, the differential relative deformation acquisition device is mainly used to collect the unsmooth release and local constraint deformation on both sides of the splicing structure or support structure.

[0038] Compared to the single-point strain acquisition by directly attaching ordinary resistance strain gauges, high-temperature strain gauges, or fiber optic strain sensors to the surface of the water-cooled wall tube 1, the differential relative deformation acquisition device in this scheme has stronger local deformation identification targeting. Ordinary strain acquisition elements mainly reflect the surface strain in a certain direction at the installation position. Their output is easily affected by adhesive layer aging, thermal cycling drift, installation prestress, local oxide layer, stress concentration near the weld, and temperature compensation error. Moreover, it is necessary to combine multiple measuring points and structural models to indirectly deduce the relative displacement or warping trend between two positions. In this embodiment, the local deformation measurement span is directly established through the reference measuring seat 3 and the follower measuring seat 4. The relative motion between the two reference positions is converted into the bending strain of the strain-sensitive beam 8 through the mechanical structure. This transforms the acquisition object from "single-point surface strain" to "differential relative deformation between two reference positions", thereby reducing the dependence on multi-point strain integration, complex boundary condition assumptions, and the accuracy of structural model back-calculation.

[0039] Example 2 This embodiment should be understood to include at least all the features of any of the foregoing embodiments, and to further improve upon them; This embodiment provides a method for early warning of local deformation of a water-cooled wall based on differential relative deformation acquisition. Based on the aforementioned system for early warning of local deformation of a water-cooled wall based on differential relative deformation acquisition, the method includes the following steps: Wall temperature data of key monitoring areas of water-cooled walls are collected through the wall temperature acquisition device of the on-site data acquisition module, and bending strain data of strain-sensitive beams are collected through the differential relative deformation acquisition device. The benchmark establishment module retrieves wall temperature and bending strain data corresponding to stable operating conditions of water-cooled walls at different operating stages and load ranges, and constructs a local deformation discrimination benchmark for key monitoring areas of water-cooled walls. The early warning output module matches the real-time collected data with the local deformation discrimination benchmark of the corresponding working condition range, and calculates the local deformation early warning index of the key monitoring area of ​​the water-cooled wall. The local deformation early warning index is compared with the preset early warning threshold to complete the risk assessment of local deformation of the water-cooled wall and output the corresponding early warning result.

[0040] Furthermore, the differential relative deformation acquisition device converts the collected bending strain of the strain-sensitive beam 8 into differential relative deformation data through a pre-calibrated structural transformation relationship. The differential relative deformation data is obtained in the following way:

[0041] Where Δd_i(t) represents the differential relative deformation data acquired by the i-th differential relative deformation acquisition device at time t, used to characterize the relative displacement, relative rotation angle, and local warping trend between two reference positions within the key monitoring area of ​​the corresponding water-cooled wall; ε_(b,i) (t) represents the bending strain of the strain-sensitive beam acquired by the differential strain acquisition element in the i-th differential relative deformation acquisition device at time t; ε_(b,i0) represents the initial bending strain of the i-th differential relative deformation acquisition device, which is obtained through cold-state no-load calibration, multiple sampling averages under the initial stable operation condition of the boiler, or verification calibration during boiler shutdown and maintenance after the differential relative deformation acquisition device is installed and the reference measuring seat, follow-up measuring seat and elongated sliding hole are locked, and stored as the zero-point reference of the differential relative deformation acquisition device. It is used to deduct the influence of installation prestress, assembly deviation and initial bending state of the strain-sensitive beam on the differential relative deformation data; K_(d,i) represents the strain differential deformation conversion coefficient of the i-th differential relative deformation acquisition device, which is obtained through calibration loading test, known relative displacement loading test, known relative rotation angle loading test or finite element structural simulation correction. It is used to characterize the correspondence between the change in bending strain of the strain-sensitive beam and the equivalent differential relative deformation between the two reference positions.

[0042] Specifically, the benchmark establishment module establishes a local deformation discrimination benchmark based on the wall temperature data and differential relative deformation data of the key monitoring area of ​​the water-cooled wall under stable operating conditions at different operating stages and load ranges. The stable operating conditions include the operating conditions where the boiler load is within a preset stable range, the burner operation status remains unchanged, the soot blowing status has not been switched, the wall temperature change rate does not exceed the preset temperature change rate threshold, and the differential relative deformation data does not show any abnormal sudden changes. The local deformation discrimination benchmark includes the differential relative deformation discrimination benchmark and the temperature change discrimination benchmark.

[0043] Specifically, the differential relative deformation discrimination criterion includes a stable differential relative deformation criterion value and an allowable differential deformation fluctuation criterion; the stable differential relative deformation criterion value is obtained based on the mean, median, or moving average of the differential relative deformation data under stable operating conditions; the allowable differential deformation fluctuation criterion is obtained based on the standard deviation, quantile difference, cold loading test results, or inspection and verification results of the differential relative deformation data under stable operating conditions.

[0044] Specifically, the temperature change discrimination criteria include a stable wall temperature reference value and an allowable temperature change reference value; the stable wall temperature reference value is obtained based on the mean, median, or moving average of wall temperature data under stable operating conditions; the allowable temperature change reference value is obtained based on the rate of change, standard deviation, or normal temperature response range of wall temperature data under stable operating conditions during historical load changes.

[0045] Specifically, the early warning output module calculates the local deformation early warning index of the key monitoring area of ​​the water-cooled wall corresponding to the current operating stage and load range by combining real-time operating data with local deformation discrimination criteria:

[0046] in, For the first Key monitoring areas of the water-cooled wall at all times The local deformation early warning index is used to determine whether there is local deformation anomaly or thermal deformation risk in the corresponding area. For the first The benchmark values ​​of stable differential relative deformation of key monitoring areas under current operating conditions; For the first The allowable differential deformation fluctuation benchmark for key monitoring areas under current operating conditions; For the wall temperature acquisition device at all times Collected wall temperature data; For the wall temperature acquisition device at all times The wall temperature data at the previous sampling time. This is a preset time interval; For the first The baseline for permissible temperature variation in key monitoring areas under current operating conditions; The temperature change enhancement coefficient is preset based on the degree of influence of wall temperature change on the risk of local thermal deformation. To prevent extremely small constants with a denominator of zero.

[0047] Specifically, the early warning output module compares the local deformation early warning index with the preset early warning threshold. When the local deformation early warning index reaches the preset early warning threshold and continues to reach the preset duration, it outputs the local deformation early warning information of the key monitoring area of ​​the corresponding water-cooled wall. The local deformation early warning information includes the location of the key monitoring area, differential relative deformation data, wall temperature data, and local deformation early warning index.

[0048] This solution establishes local deformation discrimination benchmarks for different operating stages and load ranges, allowing differential relative deformation data to be compared with normal deformation responses under current operating conditions instead of a single fixed threshold, thus improving the adaptability and accuracy of local deformation early warning. By simultaneously introducing differential relative deformation discrimination benchmarks and temperature change discrimination benchmarks, it can distinguish between predictable thermal deformation caused by normal load changes and deformation deviations caused by abnormal expansion incoordination, local warping, or abnormal support constraints, reducing the probability of false alarms. By setting the early warning index to continuously reach a preset duration before outputting early warning information, it avoids misjudgments caused by instantaneous vibration, measurement disturbances, or short-term operating condition fluctuations, making the local deformation early warning results of water-cooled walls more stable. It also provides operators with clear key monitoring area locations, differential relative deformation data, and wall temperature data, facilitating subsequent inspections and repair verifications.

[0049] Example 3 This embodiment should be understood to include at least all the features of any of the foregoing embodiments, and to further improve upon them; this embodiment provides a water-cooled wall local deformation early warning system based on differential relative deformation acquisition. The system is applied to the key area of ​​the backfire side of the water-cooled wall of a certain type of pulverized coal boiler. The outer diameter of the water-cooled wall tube 1 is 63.5 mm, the wall thickness is 7.5 mm, the center distance between adjacent water-cooled wall tubes 1 is 76 mm, and the width of the membrane fin 2 is 12.5 mm. The key monitoring area includes the furnace corner area, the area near the rigid beam support connection, the sootblower action area, the historical over-temperature area, and the tube-screen splicing area. A total of 32 sets of wall temperature acquisition devices and 32 sets of differential relative deformation acquisition devices are set on site, of which 10 sets are set in the area near the support connection, 6 sets are set in the furnace corner area, 8 sets are set in the historical over-temperature area, 5 sets are set in the tube-screen splicing area, and 3 sets are set in the sootblower action area.

[0050] In this embodiment, the wall temperature acquisition device adopts an insert-type temperature contact post 9 structure. The temperature contact post 9 has an outer diameter of 8mm and a length of 42mm, with an arc-shaped thermally conductive contact end at its end. The radius of curvature of the arc-shaped thermally conductive contact end is adapted to the curvature of the outer wall of the water-cooled wall tube 1. The temperature-sensing optical fiber is disposed inside the temperature contact post 9, with the temperature-sensing section of the optical fiber arranged close to the arc-shaped thermally conductive contact end, and is used to collect wall temperature data of the corresponding temperature-sensing area. The temperature-sensing optical fiber can be a fiber Bragg grating temperature-sensing optical fiber, a distributed temperature-sensing optical fiber, or a high-temperature resistant packaged optical fiber temperature probe, with a temperature measurement range of 0℃ to 650℃. The temperature measurement resolution is not less than 0.5℃, and the single-point temperature measurement response time is not greater than 8s. The pre-tightening spring 10 adopts a disc spring group or a helical compression spring, and the pre-tightening force is set to 18N to 35N, so that the temperature contact column 9 can still maintain stable thermal contact with the temperature measurement area during thermal cycling. The heat insulation sleeve 11 adopts a ceramic sleeve or a composite heat insulation sleeve, and the thickness of the heat insulation sleeve 11 is 2mm to 5mm. The protective box 12 adopts a heat-resistant metal shell with a thickness of 1.5mm to 3mm. The protective box 12 is provided with an inspection cover on the outside to facilitate the replacement of the temperature measuring fiber and the verification of the pre-tightening spring 10 status.

[0051] In this embodiment, the local deformation measurement span between the reference measuring seat 3 and the follower measuring seat 4 in the differential relative deformation acquisition device is set to 120mm to 260mm. For axial monitoring of the same water-cooled wall tube 1, the measurement span is preferably 180mm; for lateral displacement monitoring of adjacent water-cooled wall tubes 1, the measurement span is preferably 150mm; and for monitoring the release state of both sides of the support connector, the measurement span is preferably 220mm. The low-stiffness elastic bridge 5 uses an elastic metal plate or heat-resistant alloy elastic element with a thickness of 2mm to 3.5mm, and the bridge width is 18mm to 28mm. The flexible hinge 7 has a thickness of 0.8mm to 1.5mm and a hinge radius of 2mm to 4mm. The differential amplifying arm 6 has a length of 35mm to 60mm, and its end is connected to the strain-sensitive beam 8. The strain-sensitive beam 8 has a length of 28mm to 45mm, a width of 5mm to 8mm, and a thickness of 0.6mm to 1.2mm. The differential strain acquisition element is located at the position of maximum bending response of the strain-sensitive beam 8.

[0052] In this embodiment, the differential relative deformation acquisition device is first calibrated on a calibration platform before installation. The calibration platform applies known small relative displacements of 0.02mm, 0.05mm, 0.10mm, 0.20mm, 0.40mm and 0.80mm to the reference measuring seat 3 and the follower measuring seat 4, respectively, and applies known small relative rotation angles of 0.05°, 0.10°, 0.20° and 0.40°, respectively. The bending strain response and hysteresis error of the strain-sensitive beam 8 are recorded. In the calibration results, the repeatability error of the differential relative displacement in the range of 0.02mm to 0.80mm is no greater than ±0.015mm, the hysteresis error is no greater than 1.8% of the full scale, and the zero-point drift is no greater than 0.03mm equivalent differential relative deformation under continuous 8h constant temperature calibration conditions, which meets the requirements for identifying the local early deformation trend of the water-cooled wall.

[0053] In this embodiment, during on-site installation, a maintenance and installation window with a length of 260mm to 380mm and a width of 160mm to 220mm is first opened on the insulation layer on the back-fire side of the water-cooled wall. The surface dust, oxide layer, and loose insulation material of the area to be installed are cleaned. The reference measuring seat 3 and the follow-up measuring seat 4 can be fixed to the corresponding reference position by means of welding pads, clamping saddles, fin pressure plates, or support connectors. When the installation area is located on the outer wall of the water-cooled wall tube 1, an arc-shaped clamping saddle is preferred. When the installation area is located near the membrane fin 2 or the tube-screen splicing structure, it is preferable to use a fin pressure plate or a welding pad; when the installation area is located near the support connector, it is preferable to use a support connector auxiliary mounting base; the elongated sliding hole 13 is used to adjust the relative position of the reference measuring base 3 and the follow-up measuring base 4 before locking. The length of the elongated sliding hole 13 is set to 12mm to 24mm, and the width is set to 6mm to 10mm. After locking, anti-loosening gaskets, double nuts or heat-resistant locking pressure plates are used to prevent loosening due to thermal cycling.

[0054] In this embodiment, the working process of the differential relative deformation acquisition device is as follows: When the key monitoring area of ​​the water-cooled wall undergoes uniform thermal expansion as the boiler heats up, the reference measuring seat 3 and the follower measuring seat 4 move basically synchronously, and the low-stiffness elastic bridge 5 only produces a small follower deformation, and the output of the strain-sensitive beam 8 changes little; when there is poor sliding near the support connection, torsional deformation in the corner area, uneven heating of adjacent tubes leading to asynchronous expansion, or local misalignment in the tube-panel splicing area, differential relative motion is generated between the reference measuring seat 3 and the follower measuring seat 4. The low-stiffness elastic bridge 5 transmits this relative motion to the differential amplification arm 6. Under the constraint of the flexible hinge 7, the differential amplification arm 6 converts the small relative displacement or relative rotation angle into the bending deformation of the strain-sensitive beam 8. The differential strain acquisition element outputs the corresponding bending strain signal, and the acquisition terminal obtains the differential relative deformation data according to the pre-calibrated structural transformation relationship.

[0055] In this embodiment, the benchmark establishment module stores data according to the boiler start-up and heating stage, the stable load stage, the load increase and decrease stage, and the shutdown and cooling stage, and divides the load range into 50% to 65% of the rated load, 65% to 80% of the rated load, 80% to 95% of the rated load, and above 95% of the rated load. Within each load range, only data with a continuous stable time of not less than 40 minutes, a load change rate of not more than 1.5% of the rated load every 10 minutes, a wall temperature change rate of not more than 2°C per minute, and data after the burner has not been switched and the soot blowing action has ended for more than 30 minutes are selected as benchmark samples. At least 300 sets of valid benchmark samples are accumulated for each key monitoring area to establish a local deformation discrimination benchmark, and the benchmark is reviewed every 30 days. After each shutdown maintenance, the initial zero point and the installation locking status are reconfirmed.

[0056] In this embodiment, the early warning output module outputs local deformation risk information in three levels: attention, early warning, and severe early warning. When the differential relative deformation data exceeds the allowable fluctuation range of the current load interval but the duration is less than 10 minutes, a attention prompt is output. When the differential relative deformation data continuously exceeds the allowable fluctuation range and the wall temperature rises synchronously or the rate of change of differential relative deformation continues to increase, an early warning prompt is output. When the differential relative deformation data exceeds more than twice the allowable fluctuation range and continues for 20 minutes, or when two or more adjacent differential relative deformation acquisition devices simultaneously show abnormalities in the same direction, a severe early warning prompt is output. The early warning information includes the measuring point number, the number of the water-cooled wall tube 1, the height position, the differential relative deformation data, the wall temperature data, the duration, the early warning level, and the review suggestion.

[0057] like Figure 3 , Figure 4 As shown, in this embodiment, to verify the technical effect, comparative experiments were conducted using Comparative Example 1 and Comparative Example 2. Comparative Example 1 uses a traditional wall temperature threshold alarm scheme, which judges local risks only by whether the wall temperature exceeds a set threshold or whether the wall temperature change rate exceeds a set threshold, without collecting differential relative deformation data or establishing a local deformation discrimination benchmark. Comparative Example 2 uses a common single-point strain monitoring scheme, which sets a high-temperature resistant strain gauge on the outer wall of the water-cooled wall tube 1 and judges local deformation risks by single-point surface strain changes, without setting a reference measuring seat 3, a follow-up measuring seat 4, a low-stiffness elastic bridge 5, a differential amplification arm 6, or a flexible hinge 7, and without establishing a differential relative deformation discrimination benchmark according to different load ranges. This embodiment uses a wall temperature acquisition device, a differential relative deformation acquisition device, a local deformation discrimination benchmark for different load ranges, and a duration warning rule for joint early warning.

[0058] In this embodiment, all three schemes were continuously operated in the same water-cooled wall area for 90 days. The verification samples included 720 samples under stable load, 180 samples under increased load, 160 samples under decreased load, 96 samples before and after soot blowing, 120 samples near the support connection, 140 samples from historical over-temperature areas, and 32 samples for shutdown maintenance and verification. During the shutdown maintenance, all key monitoring areas were inspected for appearance deformation, verification of support sliding clearance, re-measurement of local tube panel flatness, and verification of mounting seat locking status. The verification results were used as the basis for judging the accuracy of the early warning.

[0059] The test results show that Comparative Example 1 has an accuracy rate of 67.8% in identifying the risk of local deformation of the water-cooled wall, an average early warning time of 1.2 hours, a false alarm rate of 18.6%, and a missed alarm rate of 21.4%; Comparative Example 2 has an accuracy rate of 79.5%, an average early warning time of 2.4 hours, a false alarm rate of 11.8%, and a missed alarm rate of 13.7%; This embodiment has an accuracy rate of 93.1%, an average early warning time of 5.6 hours, a false alarm rate of 4.3%, and a missed alarm rate of 4.9%. Among them, in the area near the support connection, this embodiment identified 4 instances of poor sliding release in advance. During the shutdown review, it was found that 3 of these instances had insufficient support clearance or slip surface jamming, and 1 instance had measurement interference caused by the external insulation material of the mounting base. After review, these were not treated as risks of the water-cooled wall body.

[0060] Furthermore, during a load increase operation, Comparative Example 1 only detected a wall temperature increase from 389℃ to 412℃, which did not reach the wall temperature alarm threshold, so no alarm was output; Comparative Example 2 showed fluctuations in the single-point strain signal at the corresponding location, but due to the inconsistent trends of adjacent measuring points, it was judged as a normal strain disturbance; In this embodiment, the differential relative deformation acquisition device located on both sides of the support connector detected that the equivalent differential relative deformation increased from 0.06mm to 0.43mm within 68 minutes, while the wall temperature increased by 7.5℃. The early warning output module determined that there was a risk of poor local expansion release in this area and output an early warning. The furnace shutdown review found that the support sliding clearance in this area decreased from 6mm under the design state to 1.8mm, and there was local ash accumulation and sliding surface jamming phenomenon. This shows that this embodiment can identify the risk of local deformation in advance before the wall temperature significantly exceeds the limit.

[0061] Furthermore, during a normal load increase, the wall temperature in the historical over-temperature zone of the water-cooled wall rose from 365℃ to 384℃. Comparative Example 1 issued one alarm due to the wall temperature change rate briefly exceeding the threshold, and Comparative Example 2 issued two abnormal alerts due to single-point strain gauge thermal drift. In this embodiment, the differential relative deformation data of the corresponding area remained within the range of 0.04mm to 0.09mm, not exceeding the allowable differential deformation fluctuation benchmark of the current load range. The warning output module only recorded the normal thermal response process and did not output a local deformation warning, indicating that this embodiment can effectively distinguish between normal thermal expansion and abnormal local deformation, reducing false alarms caused by wall temperature fluctuations and single-point strain gauge drift during normal load increases.

[0062] In this embodiment, the differential relative deformation acquisition device can also be deformed and replaced according to the installation space and the monitoring object; when the installation space is narrow, the low stiffness elastic cable tray 5 can be replaced with a leaf spring type cable tray, a bent beam type cable tray or a double thin beam parallel cable tray; when the vibration in the measurement area is obvious, the flexible hinge 7 can be replaced with a cross spring hinge or a double flexible hinge; when it is necessary to improve the sensitivity of the response to small deformations, the differential amplification arm 6 can be set as a single-arm amplification structure, a double-arm symmetrical amplification structure or a lever amplification structure; when the on-site temperature is high or the electromagnetic interference is strong, the differential strain acquisition element can be a welded resistance strain gauge, a high-temperature resistant thin film strain gauge or a fiber optic grating strain element; when the installation position is not suitable for fixing on the outer wall of the water-cooled wall tube 1, the reference measuring seat 3 and the follow-up measuring seat 4 can be fixed on the reinforcing plate of the membrane fin 2, the tube screen splicing connection plate or the auxiliary pad of the support connector.

[0063] With the setup in this embodiment, the early warning of local deformation of water-cooled walls no longer relies on a single wall temperature threshold, single-point surface strain, or manual inspection results. Instead, it uses the differential relative deformation data between two reference positions as a direct representation of the abnormal development of local structures, and combines it with the local deformation discrimination criteria under different operating stages and different load ranges for judgment. This method can improve the accuracy of identifying early risks such as poor support release, differential expansion of adjacent tubes, misalignment of tube panel splicing, and local warping of furnace corners, reduce false alarms caused by thermal cycle drift, installation prestress, and normal load changes, and provide operators with clearer key review locations and maintenance basis.

[0064] In summary, the present invention provides a water-cooled wall local deformation early warning system and method based on differential relative deformation acquisition. By converting the minute relative displacement, relative rotation angle, or local warping trend between two reference positions in the key monitoring area of ​​the water-cooled wall into quantifiable differential relative deformation data, and combining it with the wall temperature data of the corresponding area to establish a local deformation discrimination benchmark, the system can distinguish between normal thermal expansion, normal load fluctuations, and abnormal local deformation. Compared with relying solely on wall temperature thresholds, single-point strain, or manual inspection, this solution can more directly reflect the uncoordinated state of local expansion of the water-cooled wall, improve the ability to identify early deformation risks in key areas such as near support connections, furnace corners, historical over-temperature zones, and tube panel splicing areas, and thus provide more timely and reliable early warning basis for operation adjustments, key inspections, and shutdown repair and verification.

[0065] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A water-cooled wall local deformation early warning system based on differential relative deformation acquisition, characterized in that, It includes a field data acquisition module, a baseline establishment module, and an early warning output module; The field data acquisition module, benchmark establishment module, and early warning output module are electrically connected in sequence; The on-site data acquisition module is used to collect real-time operational data of key monitoring areas of the water-cooled wall. The benchmark establishment module is used to establish a local deformation discrimination benchmark for the key monitoring area of ​​the water-cooled wall; The early warning output module is used to combine real-time operating data with local deformation discrimination criteria to make early warning and discrimination of local deformation risk in key monitoring areas of water-cooled walls; The on-site data acquisition module includes a wall temperature acquisition device and a differential relative deformation acquisition device; The wall temperature acquisition device and the differential relative deformation acquisition device are both installed on the outer wall of the water-cooled wall monitoring area. The water-cooled wall monitoring area is provided with water-cooled wall tubes (1) and membrane fins (2). The wall temperature acquisition device and the differential relative deformation acquisition device are both distributed on the water-cooled wall tubes (1) and membrane fins (2).

2. The water-cooled wall local deformation early warning system based on differential relative deformation acquisition according to claim 1, characterized in that, The wall temperature acquisition device includes a temperature contact column (9), a pre-tightening spring (10), a heat insulation sleeve (11), a temperature measuring element, and a protective box (12). The preload spring (10) is sleeved on the outside of the temperature contact post (9); The heat insulation sleeve (11) is coaxially wrapped around the outer wall of the temperature contact column (9); The temperature sensing element is embedded and fixed inside the temperature contact column (9); The protective box (12) is sealed on the outside of the temperature contact column (9), the pre-tightening spring (10) and the heat insulation sleeve (11).

3. The water-cooled wall local deformation early warning system based on differential relative deformation acquisition according to claim 2, characterized in that, The bottom end of the temperature contact column (9) abuts against the outer wall of the water-cooled wall tube (1) or the surface of the membrane fin (2); The protective box (12) is a closed shell structure, and the protective box (12) is not rigidly connected to the water-cooled wall tube (1) and the membrane fin (2).

4. The water-cooled wall local deformation early warning system based on differential relative deformation acquisition according to claim 1, characterized in that, The differential relative deformation acquisition device includes a reference measuring seat (3), a follower measuring seat (4), an elongated sliding hole (13), a low-stiffness elastic bridge (5), a differential amplification arm (6), a flexible hinge (7), and a strain-sensitive beam (8). The reference measuring seat (3) and the follow-up measuring seat (4) are fixed at intervals on the surface of the water-cooled wall tube (1) or the membrane fin (2); The low-stiffness elastic bridge (5) is installed between the top of the reference measuring seat (3) and the follow-up measuring seat (4); The differential amplifier arm (6) is hinged to both ends of the low-stiffness elastic bridge (5) via a flexible hinge (7); The differential amplifier arm (6) is fixedly connected to the strain-sensitive beam (8) at its bottom end, and a differential strain acquisition element is fixedly installed on the strain-sensitive beam (8).

5. A water-cooled wall local deformation early warning system based on differential relative deformation acquisition according to claim 4, characterized in that, At least one of the reference measuring seat (3) and the follow-up measuring seat (4) is provided with an elongated sliding hole (13), which is an elongated adjustable mounting hole structure. The structural stiffness of the low-stiffness elastic cable tray (5) is less than the overall structural stiffness of the water-cooled wall tube screen.

6. The water-cooled wall local deformation early warning system based on differential relative deformation acquisition according to claim 4, characterized in that, The placement of the reference measuring seat (3) and the follow-up measuring seat (4) can be any one of the following: two positions along the same water-cooled wall tube (1), corresponding positions of adjacent water-cooled wall tubes (1), positions on both sides of the membrane fin (2), positions on both sides of the tube-screen splicing structure, or positions on both sides of the support connector.

7. A water-cooled wall local deformation early warning system based on differential relative deformation acquisition according to claim 1, characterized in that, The benchmark establishment module has built-in storage of differential relative deformation discrimination benchmark and temperature change discrimination benchmark. The differential relative deformation discrimination benchmark and temperature change discrimination benchmark are both associated with the operating parameters of the water-cooled wall at different operating stages and different load ranges.

8. A method for early warning of local deformation of a water-cooled wall based on differential relative deformation acquisition, characterized in that, A local deformation early warning system for a water-cooled wall based on differential relative deformation acquisition, according to any one of claims 1-7, includes the following steps: Wall temperature data of key monitoring areas of water-cooled walls are collected through the wall temperature acquisition device of the on-site data acquisition module, and bending strain data of strain-sensitive beams are collected through the differential relative deformation acquisition device. The benchmark establishment module retrieves wall temperature and bending strain data corresponding to stable operating conditions of water-cooled walls at different operating stages and load ranges, and constructs a local deformation discrimination benchmark for key monitoring areas of water-cooled walls. The early warning output module matches the real-time collected data with the local deformation discrimination benchmark of the corresponding working condition range, and calculates the local deformation early warning index of the key monitoring area of ​​the water-cooled wall. The local deformation early warning index is compared with the preset early warning threshold to complete the risk assessment of local deformation of the water-cooled wall and output the corresponding early warning result.

9. A method for early warning of local deformation of a water-cooled wall based on differential relative deformation acquisition according to claim 8, characterized in that, Differential relative deformation data are obtained by converting bending strain data. The specific conversion formula is as follows: in, For the first Each differential relative deformation acquisition device at time The acquired differential relative deformation data is used to characterize the relative displacement, relative rotation angle and local warping trend between two reference positions in the key monitoring area of ​​the corresponding water-cooled wall; For the first In a differential relative deformation acquisition device, the differential strain acquisition element at time... The collected bending strain of the strain-sensitive beam; For the first The initial bending strain of a differential relative deformation acquisition device; For the first The strain differential deformation conversion coefficient of the differential relative deformation acquisition device.

10. A method for early warning of local deformation of a water-cooled wall based on differential relative deformation acquisition according to claim 8, characterized in that, The process of acquiring differential relative deformation includes: When relative displacement or relative rotation occurs in the water-cooled wall monitoring area, the reference measuring seat and the follow-up measuring seat form a positional deviation. The positional deviation is transmitted to the differential amplifier arm through the low-stiffness elastic bridge. The differential amplifier arm undergoes adaptive deflection based on the flexible hinge, which in turn drives the strain-sensitive beam to produce bending deformation. The real-time bending strain data of the strain-sensitive beam is collected through the differential strain acquisition element.

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