Boiler water wall scaling reference system establishing system and pipe cutting monitoring method

Abstract

The invention discloses a boiler water-cooled wall scaling reference system establishing system and a pipe cutting monitoring method. The system comprises a plurality of deposited corrosion-resistant fixed ring sections FRRS; the FRRSs are mounted in pairs in a key scaling monitoring area of the boiler water-cooled wall, and each pair of FRRSs is welded and fixed on the same water-cooled wall tube to form a reference system unit RU; at least two RUs are established in each key scaling monitoring area, and the multiple RUs in the same area are dispersedly distributed in space; in each RU, a replaceable common water-cooled wall pipe section is arranged between the two FRRSs; the pipe cutting monitoring method comprises the steps of benchmark establishment, periodic pipe cutting monitoring and data analysis. Zero drifting of the pipe cutting position is achieved; the consistency of original states is ensured; the historical scale amount data is directly comparable, and the scale formation trend analysis error is reduced to lt; 5%; and a traditional pipe cutting weighing method is compatible, and the detection standard does not need to be changed.

Description

Technical Field

[0001] This invention belongs to the field of power plant boiler water-cooled wall condition monitoring technology, specifically involving a boiler water-cooled wall scaling reference system establishment system and tube cutting monitoring method. Background Technology

[0002] In the high-load zone of the boiler (burner zone, shield zone, etc.), water-cooled wall tubes are frequently thinned and replaced due to high-temperature corrosion and erosion. The original reference tube section location used for periodic tube cutting monitoring of internal wall scaling disappears due to tube replacement. The newly replaced tube section cannot be directly compared with historical tube cutting data due to differences in service time and original condition. This leads to interruptions in scaling trend analysis, inaccurate prediction of cleaning cycle, and difficulties in evaluating water quality control effectiveness.

[0003] Traditional pipe cutting methods make it difficult to accurately reproduce the cutting location each time (spatial position deviation). Differences in the condition of new and old pipe sections (original inner diameter, surface condition, service time) make it impossible to compare scale data, and frequent pipe cutting weakens the strength of the pipe screen. Summary of the Invention

[0004] The purpose of this invention is to provide a system for establishing a reference system for scale formation on boiler water-cooled walls and a method for monitoring pipe cutting. This ensures that all pipe cutting sampling is carried out in a strictly fixed spatial location throughout the entire life cycle of the boiler, and that the original state (inner diameter, material) of the pipe section at that location remains consistent with the initial benchmark. This enables direct, accurate, and comparable comparison of pipe cutting data from different periods, thereby solving the problem of lost reference pipe sections and incomparable historical data caused by frequent pipe replacements in high-load water-cooled walls in traditional pipe cutting methods.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A system for establishing a boiler water-cooled wall scaling reference system includes:

[0007] Multiple FRRS (Fallen Corrosion-Resistant Fixed Rings) are formed by pipe sections made of the same material as the boiler water-cooled wall base pipe. The outer surface of the FRRS is coated with a corrosion-resistant alloy layer, while the inner surface retains the original state of the base pipe. The two ends of the FRRS have pre-fabricated welded bevels, and the outer surface is laser-engraved with a unique code.

[0008] FRRS are installed in pairs in the key scaling monitoring area of ​​the boiler water-cooled wall. Each pair of FRRS is welded and fixed on the same water-cooled wall tube, and the spacing is fixed at S, forming a reference unit RU.

[0009] At least two RUs should be established in each critical scaling monitoring area, and multiple RUs in the same area should be spatially dispersed.

[0010] Within each RU, a replaceable standard water-cooled wall tube section of length S is installed between the two FRRS.

[0011] A further improvement of the present invention is that the corrosion-resistant alloy layer is a nickel-based or iron-nickel-based alloy layer containing 20-30wt% Cr, 5-10wt% Mo and 0.5-4wt% Nb, with a deposition thickness ≥0.8mm.

[0012] A further improvement of the present invention is that the key scaling monitoring area includes at least: Zone A of high heat flux density burner and Zone B of working fluid vaporization critical zone / high heat load screen zone.

[0013] A further improvement of the present invention is that the key scaling monitoring area also includes: the flame deflector / furnace outlet area Zone C.

[0014] A further improvement of the present invention is that the high heat flux density burner zone ZoneA refers to the water-cooled wall area of ​​the front wall and / or side wall within 1-2 meters above the centerline of the main burner.

[0015] A further improvement of the present invention is that the spacing S = 1000mm-2000mm.

[0016] A method for monitoring scale formation on boiler water-cooled walls by cutting tubes includes the following steps:

[0017] 1) Establishing a baseline: Immediately after the RU is installed, cut off the ordinary pipe section in between, measure and record the baseline scale amount Q0;

[0018] 2) Periodic tube cutting monitoring: During subsequent boiler operation, monitoring will be conducted according to a predetermined cycle, including:

[0019] Locate the target RU;

[0020] Cut off the currently installed conventional water-cooled wall tube section inside the RU;

[0021] Replace it with a brand new ordinary water-cooled wall tube section of the same material, specification and length, and weld it to the original FRRS;

[0022] Measure the current scale buildup Q_current on the cut pipe section using standard methods;

[0023] 3) Data analysis: Compare the scale amount (Q0, Q_current1, Q_current2,...) obtained from previous measurements of the same RU to analyze the scale trend at that location.

[0024] A further improvement of the present invention is that, in the periodic pipe cutting monitoring step, each pipe segment cut is a newly replaced pipe segment within the previous monitoring cycle, and its actual running time is equal to the length of the monitoring cycle.

[0025] A further improvement of the present invention is that the predetermined monitoring period is 1 to 3 years.

[0026] A further improvement of this invention is that the baseline scale amount Q0 is the weight of a normal pipe section, and after cleaning all scale samples, it is weighed again to calculate the scale amount before and after cleaning.

[0027] Compared with the prior art, the present invention has at least the following beneficial technical effects:

[0028] This invention provides a boiler water-cooled wall scaling reference system. The FRRS (Flag Regulator System) is composed of pipe sections made of the same material as the boiler water-cooled wall base tube, with its inner surface maintaining the original state of the base tube. This ensures that the FRRS's internal physicochemical properties are essentially consistent with the water-cooled wall base tube in the boiler operating environment, more realistically simulating the working conditions of the water-cooled wall base tube within the boiler and providing an accurate basic reference for scaling monitoring. The outer surface of the FRRS is coated with a corrosion-resistant alloy layer, effectively improving its resistance to corrosive media erosion within the boiler. Compared to ordinary water-cooled wall tubes, the FRRS can maintain its structural stability and integrity over a long period, reducing interference from structural changes caused by corrosion on scaling monitoring and ensuring reliable operation of the reference system over a longer time. Pre-fabricated welded bevels at both ends of the FRRS facilitate welding and fixing with other components, ensuring accurate and secure installation. A unique laser-engraved code on the outer surface provides a unique identifier for each FRRS, facilitating accurate identification and tracking management during installation, maintenance, and monitoring, improving the system's operability and management efficiency. FRRS (Flag Retention Resistors) are installed in pairs in key scaling monitoring areas of the boiler water-cooled wall. Each pair of FRRS is welded and fixed to the same water-cooled wall tube with a fixed spacing of S, forming a reference unit RU. This layout allows the RU to function as a relatively independent monitoring unit, exhibiting spatial regularity and stability, facilitating accurate comparison and analysis of scaling conditions. At least two RUs are established within each key scaling monitoring area, with multiple RUs within the same area spatially dispersed. This dispersed layout covers different locations within the monitoring area, fully considering the differences in water flow, temperature, and pressure within the boiler in different areas, and can more comprehensively and accurately reflect the scaling condition of the entire key scaling monitoring area, avoiding monitoring deviations caused by local special circumstances.

[0029] This invention provides a tube-cutting monitoring method for establishing a boiler water-cooled wall scaling reference system. Immediately after the RU (Ruler Unit) is installed, a section of ordinary pipe is cut and the baseline scaling amount Q0 is measured and recorded. This initial scaling data provides an accurate reference for subsequent monitoring. Since the ordinary pipe section is newly installed, its scaling condition represents the initial state before boiler operation. Subsequent scaling measurements can be compared with this baseline, allowing for a more accurate assessment of scaling growth and effectively eliminating interference from other uncertainties in scaling monitoring. The unified reference establishment method ensures comparability of monitoring data from different locations and times. Whether comparing scaling conditions in different key scaling monitoring areas of the same boiler or between different boilers, the same baseline scaling amount Q0 can be used to assess the degree and trend of scaling, providing a reliable data foundation for in-depth research on boiler water-cooled wall scaling. This invention can accurately locate the specific reference unit requiring monitoring, ensuring that each tube-cutting monitoring targets a pre-defined key scaling monitoring area, avoiding blind and arbitrary monitoring, and improving the targeting and effectiveness of monitoring. This invention, by comparing the scale accumulation (Q0, Q_current1, Q_current2, ...) measured at the same RU over multiple measurements, provides a clear visual representation of the scale accumulation at that location over time, clearly revealing the scaling trend. For example, it can determine whether the scaling exhibits linear growth, exponential growth, or periodic fluctuations, providing crucial information for in-depth analysis of scaling mechanisms and influencing factors. Furthermore, based on the analysis of scaling trends, targeted maintenance strategies for boiler water-cooled walls can be developed. If the scaling trend indicates a rapid scaling rate, it may be necessary to schedule chemical cleaning or other descaling measures in advance; if the scaling trend is relatively stable, the maintenance cycle can be appropriately extended, optimizing the allocation of maintenance resources and improving the economy and reliability of boiler operation.

[0030] In summary, the advantages of this invention are as follows: Completely eliminates reference system drift: The FRRS serves as a permanent "anchor point," ensuring zero physical deviation in the cut tube location throughout the boiler's entire lifespan. Ensures comparable original conditions: Each cut tube segment is a new tube (experiencing only a single monitoring cycle), with highly consistent original inner diameter, surface condition, and service time, minimizing the impact of differences in the tube segment's condition on scale measurement. Excellent longitudinal data comparability: Scale data (Q1, Q2, Q3...) from different cycles on the same RU are highly directly comparable, accurately reflecting the scale development trend at that point. Retains the gold standard method: Adopting the industry-recognized tube-cutting and scale-washing weighing method, the data is authoritative and requires no changes to existing testing standards and procedures. High operational feasibility: Only the initial installation of the FRRS increases workload; subsequent tube-cutting operations are almost identical to traditional methods (requiring only precise RU positioning), making it easy to promote in power plants. Long-term economic benefits: Optimizing cleaning and tube replacement strategies through precise monitoring reduces unnecessary downtime losses. Attached Figure Description

[0031] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0032] Figure 1 This is a structural diagram of the FRRS pipe section.

[0033] Figure 2 This is a schematic diagram of RU installation. Detailed Implementation

[0034] In the following description, only certain exemplary embodiments are briefly described. As those skilled in the art will recognize, the described embodiments can be modified in various ways without departing from the spirit or scope of the invention. Therefore, the drawings and description are considered to be exemplary in nature and not restrictive.

[0035] In the description of this invention, it should be understood that, when used in this specification and the appended claims, the terms "comprising" and "including" indicate the presence of the described features, integrals, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components and / or collections thereof.

[0036] It should also be understood that the terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the invention. As used in this specification and the appended claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms unless the context clearly indicates otherwise.

[0037] It should also be further understood that the term "and / or" as used in this specification and the appended claims refers to any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0038] The accompanying drawings illustrate various structural schematic diagrams according to embodiments disclosed in this invention. These drawings are not to scale, and some details have been enlarged for clarity, and some details may have been omitted. The shapes of the various regions and layers shown in the drawings, as well as their relative sizes and positional relationships, are merely exemplary and may deviate from reality due to manufacturing tolerances or technical limitations. Furthermore, those skilled in the art can design regions / layers with different shapes, sizes, and relative positions as needed.

[0039] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0040] Example 1

[0041] like Figure 1 As shown, the present invention provides a boiler water-cooled wall scaling reference system establishment system, comprising:

[0042] Multiple fused corrosion-resistant fixed ring segments (FRRS) are constructed from pipe segments made of the same material as the boiler water-cooled wall base tube. The outer surface of each FRRS is fused with a corrosion-resistant alloy layer, while the inner surface retains the original state of the base tube. The two ends of each FRRS have pre-fabricated welded bevels, and the outer surface is laser-engraved with a unique code.

[0043] The FRRS are installed in pairs in the critical scaling monitoring area of ​​the boiler water-cooled wall. Each pair of FRRS is welded and fixed on the same water-cooled wall tube, and the spacing is fixed at S to form a reference unit RU. The critical scaling monitoring area includes at least: the high heat flux density burner area Zone A and the working fluid vaporization critical zone / high heat load screen area Zone B.

[0044] At least two RUs should be established in each critical scaling monitoring area, and multiple RUs in the same area should be spatially dispersed.

[0045] Within each RU, a replaceable standard water-cooled wall tube section of length S is installed between the two FRRS.

[0046] In this embodiment, the key scaling monitoring area also includes: the flame deflector / furnace outlet zone, Zone C.

[0047] In this embodiment, the corrosion-resistant alloy layer is a nickel-based or iron-nickel-based alloy layer containing 20-30wt% Cr, 5-10wt% Mo and 0.5-4wt% Nb, with a deposition thickness ≥0.8mm.

[0048] In this embodiment, the high heat flux density burner zone Zone A refers to the water-cooled wall area of ​​the front wall and / or side wall within 1-2 meters above the centerline of the main burner.

[0049] In this embodiment, the spacing S = 1000mm-2000mm.

[0050] Example 2

[0051] This invention provides a tube-cutting monitoring method for establishing a boiler water-cooled wall scaling reference system, comprising the following steps:

[0052] 1) Establishing a baseline: Immediately after the RU is installed, cut off the ordinary pipe section in between, measure and record the baseline scale amount Q0;

[0053] 2) Periodic tube cutting monitoring: During subsequent boiler operation, monitoring will be conducted according to a predetermined cycle, including:

[0054] Locate the target RU;

[0055] Cut off the currently installed conventional water-cooled wall tube section inside the RU;

[0056] Replace it with a brand new ordinary water-cooled wall tube section of the same material, specification and length, and weld it to the original FRRS;

[0057] Measure the current scale buildup Q_current on the cut pipe section using standard methods;

[0058] 3) Data analysis: Compare the scale amount (Q0, Q_current1, Q_current2,...) obtained from previous measurements of the same RU to analyze the scale trend at that location.

[0059] In this embodiment, in the periodic pipe cutting monitoring step, each pipe segment cut is a newly replaced pipe segment within the previous monitoring cycle, and its actual running time is equal to the length of the monitoring cycle.

[0060] In this embodiment, the predetermined monitoring period is 1 to 3 years.

[0061] In this embodiment, the baseline scale amount Q0 is the weight of a normal pipe section. After cleaning all scale samples, the scale is weighed again, and the scale amount before and after cleaning is calculated.

[0062] Example 3

[0063] This invention provides a tube-cutting monitoring method for establishing a boiler water-cooled wall scaling reference system, comprising:

[0064] Step 1. Preparation and installation of the fused corrosion-resistant fixing ring (FRRS)

[0065] 1. FRRS structural parameters

[0066] Base tube material: consistent with the boiler water-cooled wall base tube (such as SA-210C, 15CrMoG) to ensure that the coefficient of thermal expansion and mechanical properties are matched.

[0067] Dimensions: Length 450mm, outer diameter / wall thickness same as the original water-cooled wall tube (Example: ).

[0068] Melt layer design:

[0069] Area: Outer surface of the base tube.

[0070] Material: Inconel 625 nickel-based alloy powder (composition: Ni-based, Cr 22%, Mo 9%, Nb 3.5%).

[0071] Thickness: 1.2mm (tolerance ±0.1mm), porosity <1%.

[0072] Process: Laser cladding (power 4.5kW, scanning speed 1.0m / min, argon protection).

[0073] Identification: A unique code is laser-engraved on the outer surface (e.g., “FRRS-Front Wall-A1”), with a temperature resistance of >1000℃.

[0074] 2. Layout of key scaling monitoring areas (taking a 600MW supercritical boiler as an example)

[0075]

[0076] Total: 6 pairs of FRRS (12 roots), forming 6 reference unit (RU).

[0077] 3. Installation Process

[0078] Step 1: Shut down the boiler and cool it down to below 50°C.

[0079] Step 2: Cut the original water-cooled wall tubes according to the design position, and grind the cut edges.

[0080] Step 3: Solder the FRRS to its original position (see...) Figure 2 ):

[0081] [Original Pipe Section]—(Welding)—[FRRS-A1]—(Welding)—[Ordinary Pipe Section S=1500mm]—(Welding)—[FRRS-A2]—(Welding)—[Original Pipe Section]

[0082] Step 4: Welding is performed using full argon arc welding, and 100% radiographic testing (RT) is qualified.

[0083] Step 5: Record the three-dimensional coordinates of each FRRS (e.g., FRRS-A1: X = 5m from the steel frame column, Y = elevation 28.3m, Z = 2.4m to the left of the center line of the front wall).

[0084] Step 2. Construction of Reference Frame (RU) and Establishment of Baseline

[0085] 1. RU structural parameters

[0086] Length S: The spacing between the two FRRS is fixed at 1500mm (ordinary pipe section length can be replaced).

[0087] Standard pipe section: Material / specifications are the same as the original water-cooled wall pipe, with an original inner diameter tolerance of ±0.3mm.

[0088] 2. Standard pipe cutting operation (after initial installation)

[0089] Step 1: Locate the RU (e.g., RU-A1 corresponds to FRRS-A1 and FRRS-A2).

[0090] Step 2: Cut off the middle 1500mm ordinary pipe section (mechanical cutting to avoid the heat-affected zone).

[0091] Step 3: Measure the baseline data:

[0092] Reference inner diameter D0: Measured with an inside micrometer at both ends and the midpoint of the pipe section, for example:

[0093] Baseline scale amount Q0: Weigh a 1500mm long ordinary pipe section, clean all scale samples, weigh again, and calculate the scale amount before and after cleaning (e.g., 120g / m). 2 ).

[0094] Step 4: Replace with a new pipe section of the same specification and weld it back in place.

[0095] Step 5: Record the data and associate it with the RU number.

[0096] Step 3. Periodic pipe cutting monitoring (taking a 2-year cycle as an example)

[0097] 1. Operating Procedures

[0098] Step 1: Shut down the boiler and cool it down. Locate the target RU (e.g., RU-A1) according to the boiler reference map.

[0099] Step 2: Cut the ordinary pipe section in the current RU (this pipe section is a new pipe that was replaced 2 years ago).

[0100] Step 3: Immediately install a brand new standard pipe section (1500mm in length, inner diameter...) (Deviation from D0 < 0.1%).

[0101] Step 4: Measure the amount of scale on the cut pipe section:

[0102] Cleaning area: Avoid the middle 1000mm pipe section with weld seams ≥50mm.

[0103] Weigh the scale to obtain the current scale amount Q_current (e.g., 285 g / m³). 2 ).

[0104] Example 4: A 300MW subcritical coal-fired boiler.

[0105] This implementation method fully presents the details of technical implementation, covering material selection, positioning rules, operation steps, and data verification, ensuring that technicians in the relevant field can implement it accordingly. The core innovation—the "permanent FRRS anchor point + consumable sampling section" structure—fundamentally solves the reference system drift problem while remaining compatible with traditional pipe cutting standards.

[0106] FRRS:

[0107] Material: SA-210C (same as water-cooled wall base tube).

[0108] Length: 450mm.

[0109] The outer surface is laser-coated with Inconel 625 (Cr 22%, Mo 9%, Nb 3.5%), with a thickness of 1.2 mm.

[0110] Marking: Laser engraving "FRRS-Front Wall-A1".

[0111] RU Layout:

[0112] Zone A (Burner Zone - Front Wall): 3 RUs are arranged: RU-A1 (pipe bank 5, elevation 28m), RU-A2 (pipe bank 15, elevation 28.5m), RU-A3 (pipe bank 25, elevation 29m). The length of the ordinary pipe section in the middle of each RU is S = 1500mm.

[0113] Zone B (High Heat Load Zone): 2 RUs (RU-B1, RU-B2) are arranged.

[0114] Total: 5 RUs (requires 10 FRRSs).

[0115] Monitoring cycle: Pipe cutting monitoring shall be carried out every 2 years, and the procedure is as follows:

[0116] First pipe cutting cycle: Install FRRS and RU, and perform the first reference pipe cutting for each RU (measure Q0_A1, Q0_A2, Q0_A3, Q0_B1, Q0_B2).

[0117] Second pipe cutting cycle: Locate RU-A1, cut off the pipe section that has been in operation for 2 years, and measure Q_2027_A1; replace with a new pipe section. Perform the same operation on RU-A2, A3, B1, and B2.

[0118] The third pipe cutting cycle: Repeat the cutting of RU-A1 (this time the new pipe to be replaced in 2027 is being cut)...and so on.

[0119] In summary, the boiler water-cooled wall scaling reference system and tube cutting monitoring method provided by this invention have the following advantages:

[0120] 1. Structural innovation: In the high corrosion / scaling areas of the boiler (burner area, vaporization critical area, etc.), a corrosion-resistant fixed ring segment (FRRS) is welded and deposited. The outer surface and ends are coated with a corrosion-resistant alloy layer (such as Ni-Cr-Mo alloy), while the inner surface retains the original state of the base tube.

[0121] 2. Reference system construction: Pairs of FRRS (1000–2000 mm spacing) form permanent "anchor points", and replaceable ordinary pipe sections are installed in the middle to form a reference unit (RU);

[0122] 3. Monitoring method: The first time, a normal pipe section in the RU is cut to establish a baseline (D0, Q0); in subsequent cycles, the newly replaced pipe section at the same location is precisely cut (only a single monitoring cycle is performed) and the scale content (Q_current) is measured.

[0123] The advantages of this invention are: zero drift in the tube cutting position (FRRS never needs to be replaced); consistent original state (each time a "new tube" is cut); direct comparability of historical scale data, and reduction of scaling trend analysis error to <5%; and compatibility with traditional tube cutting and weighing methods, without the need to change the testing standards.

[0124] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the scope of the invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0125] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can be appropriately combined to form other embodiments that can be understood by those skilled in the art. The above content is only for illustrating the technical concept of the present invention and should not be construed as limiting the scope of protection of the present invention. Any modifications made based on the technical concept proposed in this invention shall fall within the scope of protection of the claims of this invention.

Claims

1. A system for establishing a reference system for scale formation on boiler water-cooled walls, characterized in that, include: Multiple FRRS (Fallen Corrosion-Resistant Fixed Rings) are formed by pipe sections made of the same material as the boiler water-cooled wall base pipe. The outer surface of the FRRS is coated with a corrosion-resistant alloy layer, while the inner surface retains the original state of the base pipe. The two ends of the FRRS have pre-fabricated welded bevels, and the outer surface is laser-engraved with a unique code. FRRS are installed in pairs in the key scaling monitoring area of ​​the boiler water-cooled wall. Each pair of FRRS is welded and fixed on the same water-cooled wall tube, and the spacing is fixed at S, forming a reference unit RU. At least two RUs should be established in each critical scaling monitoring area, and multiple RUs in the same area should be spatially dispersed. Within each RU, a replaceable standard water-cooled wall tube section of length S is installed between the two FRRS.

2. The boiler water-cooled wall scaling reference system establishment system according to claim 1, characterized in that, The corrosion-resistant alloy layer is a nickel-based or iron-nickel-based alloy layer containing 20-30wt% Cr, 5-10wt% Mo and 0.5-4wt% Nb, with a deposition thickness ≥0.8mm.

3. The boiler water-cooled wall scaling reference system establishment system according to claim 1, characterized in that, The key fouling monitoring areas include at least: Zone A, the high heat flux density burner zone, and Zone B, the critical working fluid vaporization zone / high heat load screen zone.

4. A boiler water-cooled wall scaling reference system establishment system according to claim 3, characterized in that, Key scaling monitoring areas also include: Zone C, the area at the flame deflector / furnace outlet.

5. A boiler water-cooled wall scaling reference system establishment system according to claim 3, characterized in that, The high heat flux density burner zone, Zone A, refers to the water-cooled wall area of ​​the front and / or side walls within 1-2 meters above the centerline of the main burner.

6. A boiler water-cooled wall scaling reference system establishment system according to claim 1, characterized in that, Spacing S = 1000mm - 2000mm.

7. A tube-cutting monitoring method for establishing a boiler water-cooled wall scaling reference system according to any one of claims 1-6, characterized in that, Includes the following steps: 1) Establishing a baseline: Immediately after the RU is installed, cut off the ordinary pipe section in between, measure and record the baseline scale amount Q0; 2) Periodic tube cutting monitoring: During subsequent boiler operation, monitoring will be conducted according to a predetermined cycle, including: Locate the target RU; Cut off the currently installed conventional water-cooled wall tube section inside the RU; Replace it with a brand new ordinary water-cooled wall tube section of the same material, specification and length, and weld it to the original FRRS; Measure the current scale buildup Q_current on the cut pipe section using standard methods; 3) Data analysis: Compare the scale amount (Q0, Q_current1, Q_current2,...) obtained from previous measurements of the same RU to analyze the scale trend at that location.

8. The method for monitoring scale formation in a boiler water-cooled wall according to claim 7, characterized in that, In the periodic pipe cutting monitoring step, each pipe segment cut is a newly replaced pipe segment within the previous monitoring cycle, and its actual running time is equal to the length of that monitoring cycle.

9. The method for monitoring scale formation in a boiler water-cooled wall according to claim 7, characterized in that, The planned monitoring period is 1 to 3 years.

10. The method for monitoring scale formation in a boiler water-cooled wall according to claim 7, characterized in that, The baseline scale amount Q0 is the weight of a normal pipe section. After cleaning all scale samples, the scale is weighed again, and the scale amount before and after cleaning is calculated.

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