A method for evaluating the state of a supercritical or ultra-supercritical boiler steam-water separator body

Abstract

A state assessment method for a supercritical or ultra-supercritical boiler water separator body comprises the following steps: 1) clarifying the assessment object and basic information; 2) clarifying the specific stage of the full life cycle of the assessment object; 3) calculating the state factor; 4) calculating the correction factor; 5) clarifying the detailed assessment points; 6) formulating and implementing a metal inspection plan; 7) obtaining metal inspection results; 8) assessing the state of the assessment point; 9) assessing the state of the assessment object; 10) archiving and feedback of the assessment results. The present invention can help thermal power plant technicians to better formulate maintenance strategies.

Description

Technical Field

[0001] The invention belongs to the technical field of equipment status assessment in thermal power plants, and in particular relates to a method for assessing the status of a supercritical or ultra-supercritical boiler steam-water separator body. Background Art

[0002] The steam-water separator of a supercritical or ultra-supercritical boiler is an important component of the boiler system of a thermal power plant. In recent years, large-scale high-parameter supercritical or ultra-supercritical thermal power units have frequently participated in the peak load operation of the power grid, which makes the steam-water separator of a supercritical or ultra-supercritical boiler in a relatively harsh working condition during operation and is easily affected by the action of thermal alternating loads. In particular, as a thick-walled component, the steam-water separator body has a relatively high temperature difference stress. The temperature difference between the inner and outer walls of the cylinder is linearly distributed along the wall thickness. The greater the thickness, the greater the temperature difference, and the greater the stress. Since the steam-water separator of a supercritical or ultra-supercritical boiler is located outside the boiler, if a leakage accident occurs in the body, there is a risk of causing major personal safety and economic losses. Therefore, it is necessary to more accurately evaluate the status of the supercritical or ultra-supercritical boiler steam-water separator body.

[0003] For supercritical or ultra-supercritical boiler steam-water separators, there are literature reports on transient stress analysis of steam-water separators based on three-dimensional finite element models, such as the literature "Transient stress finite element analysis of 1000MW boiler steam-water separators, Boiler Technology, 2013 (1)". There are also literature reports on the life loss calculation method of the steam-water separator under fatigue-creep interaction based on elastic analysis, such as the literature "Cold start safety analysis of steam-water separators of ultra-supercritical 1000MW units, Thermal Power Generation, 2015 (2)". Whether it is stress analysis or life loss calculation, the following conditions are required: the evaluator needs to have rich basic knowledge of mathematical analysis, basic knowledge of metal materials, knowledge of mechanical calculation, knowledge and experience of life assessment; it is necessary to collect complete design information and design data; it is necessary to collect complete operation history data; it is necessary to collect complete and comprehensive metal inspection related data; it is necessary to construct stress field and temperature field models; it is necessary to conduct comprehensive laboratory analysis data of samples of the same material as a reference group, etc. These complex conditions determine that the development of technologies such as stress analysis and life loss calculation is limited to professional technical institutions and personnel, and the collection of these basic information and data, complete and comprehensive metal inspection and laboratory analysis will lead to an increase in power plant maintenance costs and labor costs.

[0004] Therefore, it is necessary to find a universal method that does not require the evaluator to have rich basic knowledge of mathematical analysis, basic knowledge of metal materials, knowledge of mechanical calculation, knowledge and experience of life assessment, nor does it need to bear additional testing costs. Only by obtaining existing metal inspection data, the condition of the supercritical or ultra-supercritical boiler steam-water separator body can be evaluated, thereby directly helping thermal power plant technicians to formulate maintenance strategies. Summary of the invention

[0005] In order to overcome the above technical problems, the purpose of the present invention is to provide a state assessment method for a supercritical or ultra-supercritical boiler steam-water separator body to help thermal power plant technicians better formulate maintenance strategies.

[0006] In order to achieve the above object, the technical solution adopted by the present invention and the beneficial effects of the present invention are:

[0007] A method for evaluating the state of a supercritical or ultra-supercritical boiler steam-water separator body comprises the following steps;

[0008] 1) Clarify the assessment object and basic information;

[0009] 2) Identify the specific stage of the life cycle of the assessment object;

[0010] 3) Calculate the state factor;

[0011] 4) Calculate the correction factor;

[0012] 5) Clarify detailed assessment points;

[0013] 6) Develop and implement metal inspection plans;

[0014] 7) Obtain metal inspection results;

[0015] 8) Assessment point status assessment;

[0016] 9) Assessment of the status of the assessment object;

[0017] 10) Archive and provide feedback on evaluation results.

[0018] The evaluation object of step 1) is the supercritical or ultra-supercritical boiler steam-water separator body, and the basic information includes design drawings, design diameter, design wall thickness, design material and detailed replacement or maintenance record files.

[0019] The specific operation steps of step 2) are:

[0020] It is clear whether the supercritical or ultra-supercritical boiler water separator is in the early stage, middle stage, late stage or final stage of its life cycle;

[0021] All stages of the life cycle Time range of each stage of the life cycle Early stage <![CDATA[(0,0.1L c ]]]> Mid-term <![CDATA[(0.1L c ,0.6L c ]]> Late Stage <![CDATA[(0.6L c ,0.85L c ]]> Terminal stage <![CDATA[(0.85L c ,L c ]]]>

[0022] Among them, L c The design life is defined as the design life of the unit is 30 years.

[0023] The specific operation steps for calculating the state factor in step 3) are:

[0024] Based on the stage of the evaluation object identified in step 2), determine its corresponding status factor C S ;

[0025] All stages of the life cycle <![CDATA[State factor C S > Early stage 1+2s Mid-term 1+1s Late Stage 1+3s Terminal stage 1+5s

[0026] According to the design and manufacturing data collected in step 1), the value of s is found according to the table below.

[0027]

[0028] The specific steps for calculating the correction factor in step 4) are as follows:

[0029] Based on the feedback of the most recent evaluation result of the evaluation object, the correction factor C is determined according to formula (1): f ;

[0030]

[0031] In the formula, the values ​​of parameters δ and f can be found in the table below.

[0032]

[0033] The specific operation steps of step 5) are:

[0034] Identify all assessment points of the assessment object and divide them into: shell assessment point, head assessment point, longitudinal weld assessment point and girth weld assessment point, distinguished by the following subscripts bd, dh, lw and gw respectively.

[0035] The specific operation steps of step 6) are:

[0036] Taking into account the maintenance plan, time and cost, for all the evaluation points determined in step 5), select appropriate items from macro inspection, surface flaw detection, non-destructive testing, metallographic inspection, wall thickness measurement, and hardness inspection to develop and implement a metal inspection plan.

[0037] The specific operation steps of step 7) are:

[0038] According to the metal inspection items determined in step 6), the metal inspection results of each assessment point are obtained, the state parameters are divided into three categories according to the metal inspection results, and the state parameters CP and weights Q corresponding to each metal inspection item at each assessment point are confirmed.

[0039]

[0040]

[0041] The specific operation steps of step 8) are:

[0042] According to the metal inspection results obtained in step 7), the status of a single assessment point is evaluated and the status of the single assessment point is defined as C j , the evaluation model is shown in formula (2);

[0043]

[0044] Status C of the evaluation point j The numerical results of C normally fall within the range of [0,3.2]. j When the value of changes from 0 to 3.2, the status of the evaluation point becomes worse and worse;

[0045] The weights Q of the three types of state parameters in formula (2) are Ai , Q Bi and Q Ci The value of gives the rule of formula (3);

[0046]

[0047] The specific operation steps in step 9) are:

[0048] The evaluation results of all evaluation points obtained in step 8) are counted according to the classification of shell evaluation points, head evaluation points, longitudinal weld evaluation points and girth weld evaluation points (the subscripts are bd, dh, lw and gw respectively), and the number of shell evaluation points k, head evaluation points l, longitudinal weld evaluation points m and girth weld evaluation points n are counted. Then, the evaluation object is evaluated as a whole. The evaluation model of the final state value is shown in formula (10);

[0049]

[0050] If the C value of the status of the evaluation object is 0, the status of the evaluation object is considered to be the best. When the C value changes from 0 to 3.2, the status of the evaluation object gradually deteriorates. When the C value is greater than 2, the status of the evaluation object is general, but some evaluation points are in poor condition, which should attract the attention of technical personnel. When the C value is greater than 2.5, the status of the evaluation object is poor, and most evaluation points are in poor condition. Especially at the end and terminal stage of the entire life cycle, if the status C value of the evaluation object gradually increases after multiple consecutive evaluations, it also confirms that the status of the evaluation object is poor, and the enterprise should be prepared to replace the entire evaluation object. The specific operation steps of step 10) are:

[0051] The status assessment results of the assessment object obtained in step 9) are completely archived and recorded, and are used as feedback for the next assessment to calculate the correction factor in step 4).

[0052] The first type of state parameter in step 8): macroscopic state parameter CP A1-j , according to the results of macroscopic inspection M A1-j : {no defects found, a small number of suspected defects found, obvious defects found} is defined as shown in formula (4):

[0053]

[0054] The first type of state parameter in step 8): surface state parameter CP A2-j , according to the surface flaw detection results M A2-j : {no defects found, surface defects found but eliminated after polishing, surface defects found but still exist after polishing} is defined as shown in formula (5):

[0055]

[0056] The second type of state parameter in step 8): lossless state parameter CP B1-j , according to the results of nondestructive testing M B1-j :{Level I, Level II, Level III, Level IV} definition, as shown in formula (6):

[0057]

[0058] The second type of state parameter in step 8): tissue state parameter CP B2-j , according to the results of metallographic examination B2-j : {level 1, level 2, level 3, level 4, level 5} is defined as shown in formula (7):

[0059]

[0060] The third type of state parameter in step 8): wall thickness state parameter CP C1-j , according to the wall thickness inspection result M C1-j The definition is as shown in formula (8):

[0061]

[0062] In formula (8), d0 is the designed wall thickness, in mm;

[0063] The third type of state parameter in step 8): hardness state parameter CP C2-j , according to the hardness test results M C2-j The definition is as shown in formula (9):

[0064]

[0065] In formula (7), M C2-j The value range of is related to the material.

[0066] Beneficial effects of the present invention:

[0067] The present invention does not require the assessor to have rich basic knowledge of metal materials, mechanical calculation knowledge, life assessment knowledge and experience, nor does it need to bear additional test costs. Based on conventional metal inspection data such as macroscopic inspection, surface flaw detection, non-destructive testing, metallographic inspection, wall thickness measurement, and hardness inspection of the supercritical or ultra-supercritical boiler steam-water separator body, the state of the supercritical or ultra-supercritical boiler steam-water separator body is evaluated by correcting the state factor and the correction factor, thereby directly helping the technical personnel of the thermal power plant to formulate the next maintenance strategy. If the state C value of the supercritical or ultra-supercritical boiler steam-water separator body gradually increases and the state becomes worse and worse after multiple consecutive evaluations, the enterprise should be prepared to replace the entire evaluation object.

[0068] Taking the results of the C repair of the left steam-water separator body of a 660MW supercritical boiler in December 2020 as an example, the status assessment was implemented according to the method of this invention, and the assessment process and final results are shown as follows.

[0069]

[0070]

[0071] BRIEF DESCRIPTION OF THE DRAWINGS

[0072] Figure 1 It is a schematic diagram of the state evaluation process of the present invention. DETAILED DESCRIPTION

[0073] The present invention is further described below in conjunction with the accompanying drawings and implementation examples.

[0074] like Figure 1 As shown:

[0075] 1) Clarify the evaluation object and basic information

[0076] First, it is clear that the evaluation object is the supercritical or ultra-supercritical boiler steam-water separator body. This method can be used to evaluate the cylinder, head, longitudinal weld or girth weld.

[0077] In addition, it is also necessary to collect and clarify the design drawings, design diameter, design wall thickness, design material, and detailed replacement or maintenance record files of the evaluation object.

[0078] 2) Identify the specific stage of the life cycle of the assessment object

[0079] The status of the evaluation object has a certain relationship with the specific stage of its life cycle. In the early stage of the life cycle, the equipment is not in good condition due to design and manufacturing defects and installation legacy hazards. With the stable operation of the unit, the operating personnel gradually become familiar with the equipment. After entering the mid-term stage of the life cycle, the evaluation object reaches the best state and can last for a long time. When entering the final stage of the life cycle, under the influence of the long-term peak-shaving operation of the unit, the state of the evaluation object gradually deteriorates. When entering the final stage of the life cycle, under long-term high temperature and high pressure service conditions, the material gradually accelerates aging, and the state of the evaluation object deteriorates rapidly.

[0080] It is necessary to clearly define the stage of the life cycle in which the assessment object is located: the early stage, mid-stage, late stage, or terminal stage.

[0081]

[0082]

[0083] Among them, L c The design life is generally defined as the design life of the unit is 30 years.

[0084] 3) Calculate the state factor

[0085] Based on 2) the stage of the evaluation object, determine its corresponding status factor C S ;

[0086] All stages of the life cycle <![CDATA[State factor C S > Early stage 1+2s Mid-term 1+1s Late Stage 1+3s Terminal stage 1+5s

[0087] According to the design and manufacturing data collected in 1), the value of s is found according to the table below.

[0088]

[0089] If all indicators in the design and manufacturing data are normal and no major problems are found, c takes a value of 0.01. Otherwise, based on the problems found in the design and manufacturing stages, the evaluator can also make adjustments based on the actual situation of the component.

[0090] 4) Calculate the correction factor

[0091] Based on the feedback of the most recent evaluation result of the evaluation object, the correction factor C is determined according to formula (1): f ;

[0092]

[0093] In the formula, the values ​​of parameters δ and f can be found in the table below.

[0094]

[0095] 5) Clarify detailed evaluation points

[0096] In order to understand the actual status of the evaluation object in detail, it is generally recommended to select multiple positions (cylinder, head, longitudinal weld and girth weld) of the evaluation object for inspection. Since the inspection points will eventually participate in the status assessment, they are also called evaluation points, and the evaluation points are divided into: cylinder evaluation points, head evaluation points, longitudinal weld evaluation points and girth weld evaluation points, which are distinguished by the following subscripts bd, dh, lw and gw respectively.

[0097] 6) Develop and implement metal inspection plans

[0098] Taking into account the maintenance plan, time and cost, for all the evaluation points determined in step 5), select appropriate items from macro inspection, surface flaw detection, non-destructive testing, metallographic inspection, wall thickness measurement, and hardness inspection to develop and implement a metal inspection plan.

[0099]

[0100]

[0101] 7) Obtain metal inspection results

[0102] According to the metal inspection items determined in step 6), the metal inspection results of each assessment point are obtained, the state parameters are divided into three categories according to the metal inspection results, and the state parameters CP and weights Q corresponding to each metal inspection item at each assessment point are confirmed.

[0103]

[0104] 8) Assessment point status assessment

[0105] According to the metal inspection results obtained in 7), the status of a single assessment point is evaluated and the status of the single assessment point is defined as C j , the evaluation model is shown in formula (2).

[0106]

[0107] Status C of the evaluation point j The numerical result of normally falls within the range of [0,3.2]. If C j The value is 0, then the state of the evaluation point is optimal. j When the value of changes from 0 to 3.2, the status of the evaluation point becomes worse and worse.

[0108] Taking into account the importance of various metal inspection items, their implementation frequency, and the accuracy of the results, the weights Q of the three types of state parameters in formula (2) are:Ai , Q Bi and Q Ci The value of gives the rule of formula (3);

[0109]

[0110] The following is a method for evaluating the three types of state parameters at a single evaluation point.

[0111] 8.1) Evaluation of the first type of state parameters

[0112] 8.1.1) Evaluation of macro state parameters corresponding to macro inspection

[0113] Results of macroscopic inspection A1-j Generally, it is one of the items in the set {no defects found, defects found, defects exceeding the standard found}, and its corresponding macro state parameter CP A1-j The definition of is shown in formula (4).

[0114]

[0115] 8.1.2) Evaluation of surface condition parameters corresponding to surface flaw detection

[0116] Surface flaw detection results M A2-j Generally, it is {no defects found, surface defects found but eliminated after polishing, surface defects found but still exist after polishing}, and its corresponding surface state parameter CP A2-j The definition of is shown in formula (5).

[0117]

[0118] 8.2) Evaluation of the second type of state parameters

[0119] 8.2.1) Evaluation of nondestructive state parameters corresponding to nondestructive testing

[0120] Nondestructive testing can be carried out by ultrasonic, magnetic particle, penetrant or radiographic testing according to actual conditions. The results of nondestructive testing are B1-j Generally defined as {Level I, Level II, Level III, Level IV}, if multiple NDT projects are implemented, the highest rating is selected as the NDT result, and its corresponding nondestructive status parameter CP B1-j The definition of is shown in formula (6).

[0121]

[0122] 8.2.2) Evaluation of non-destructive state parameters corresponding to metallographic examination

[0123] Results of metallographic examination B2-jGenerally defined as {level 1, level 2, level 3, level 4, level 5}, the corresponding tissue state parameter CP B2-j The definition of is shown in formula (7).

[0124]

[0125] 8.3) Evaluation of the third type of state parameters

[0126] 8.3.1) Evaluation of wall thickness status parameters corresponding to wall thickness inspection

[0127] During high-temperature operation, the object being evaluated will be subjected to steam erosion and corrosion, which will cause high-temperature oxidation. This process will consume the base metal of the object being evaluated, causing the wall thickness of the object to be thinner, bear greater stress, and be in a worse state. C1-j Corresponding wall thickness state parameter CP C1-j The definition of is shown in formula (8).

[0128]

[0129] In formula (8), d0 is the designed wall thickness, in mm.

[0130] 8.3.2) Evaluation of hardness state parameters corresponding to hardness inspection

[0131] When the object to be evaluated is operated under high temperature conditions, it will gradually age, causing the hardness to gradually decrease. The decrease in hardness will make the state of the object to be evaluated worse, which may lead to failure. C2-j Corresponding hardness state parameter CP C2-j The definition of is shown in formula (9).

[0132]

[0133] In formula (9), M C2-j The value range of is related to the material.

[0134] 9) Evaluation of the status of the evaluation object

[0135] For all the evaluation points obtained in 8), statistics are performed according to the classification of shell evaluation points, head evaluation points, longitudinal weld evaluation points and girth weld evaluation points (the subscripts are bd, dh, lw and gw respectively), and the number of shell evaluation points k, head evaluation points l, longitudinal weld evaluation points m and girth weld evaluation points n are counted. Then, the evaluation object is evaluated as a whole. The evaluation model of the final state value is shown in formula (10).

[0136]

[0137] If the status C value of the evaluation object is 0, the status of the evaluation object is considered to be the best. When the C value changes from 0 to 3.2, the status of the evaluation object gradually deteriorates. When the C value is greater than 2, the status of the evaluation object is general, but some evaluation points are in poor condition, which should attract the attention of technical personnel. When the C value is greater than 2.5, the status of the evaluation object is poor, and most evaluation points are in poor condition. Especially at the end and terminal stages of the entire life cycle, if the status C value of the evaluation object gradually increases after multiple consecutive evaluations, it also confirms that the status of the evaluation object is poor, and the enterprise should be prepared to replace the entire evaluation object.

[0138] 10) Archiving and feedback of evaluation results

[0139] The state evaluation results of the evaluation object obtained in step 9) are fully recorded and fed back for the next evaluation to calculate the correction factor in step 4).

[0140] The above technical scheme is used to evaluate the state of the supercritical or ultra-supercritical boiler steam-water separator body, which can not only help the technical personnel of the thermal power plant understand the actual state of the supercritical or ultra-supercritical boiler steam-water separator body, but also predict the change trend of its state through multiple state evaluation results for the same evaluation point, and can also comprehensively evaluate the overall state of the supercritical or ultra-supercritical boiler steam-water separator body based on the state results of all evaluation points, which is of great significance for formulating maintenance plans and replacement strategies.

Claims

1. A method for evaluating the state of a supercritical or ultra-supercritical boiler steam-water separator body, characterized in that: The steps include: 1) Clarify the assessment object and basic information; 2) Identify the specific stage of the life cycle of the assessment object; 3) Calculate the state factor; 4) Calculate the correction factor; 5) Clarify detailed assessment points; 6) Develop and implement metal inspection plans; 7) Obtain metal inspection results; 8) Assessment point status assessment; 9) Assessment of the status of the assessment object; 10) Archiving and feedback of evaluation results; The specific operation steps of step 2) are: Specify the stage of the supercritical or ultra-supercritical boiler water separator body in the early stage, middle stage, late stage and final stage of the whole life cycle; Among them, L c The design life is generally defined as the design life of the unit is 30 years; The specific operation steps in step 9) are: For all the evaluation points obtained in step 8), statistics are performed according to the classification of shell evaluation points, head evaluation points, longitudinal weld evaluation points and girth weld evaluation points, with the subscripts bd, dh, lw and gw respectively. The number of shell evaluation points k, head evaluation points l, longitudinal weld evaluation points m and girth weld evaluation points n are counted, and then the evaluation object is evaluated as a whole. The evaluation model of the final state value is shown in formula (10); When the C value of the status of the evaluation object is 0, it is considered that the status of the evaluation object is the best. When the P value changes from 0 to 3.2, the status of the evaluation object gradually deteriorates. When the C value is greater than 2, the status of the evaluation object is general, and some evaluation points are in poor condition, which should attract the attention of technical personnel. When the C value is greater than 2.5, the status of the evaluation object is poor, and most evaluation points are in poor condition. Especially at the end and terminal stage of the whole life cycle, if the status C value of the evaluation object gradually increases after multiple consecutive evaluations, it also confirms that the status of the evaluation object is poor, and the enterprise should be prepared to replace the evaluation object as a whole. The specific operation steps in step 10) are: Completely record and archive the status assessment results of the assessment object obtained in step 9) and provide feedback for the next assessment to calculate the correction factor in step 4); The specific operation steps of step 4) are: Based on the feedback of the most recent evaluation result of the evaluation object, the correction factor C is determined according to formula (1): f ; In the formula, the values ​​of parameters δ and f can be found in the following table; The specific operation steps of step 8) are: According to the metal inspection results obtained in step 7), the status of a single assessment point is evaluated and the status of the single assessment point is defined as C j , the evaluation model is shown in formula (2); if Max(CP Ai-j ,CP Bi-j ,CP Ci-j )<1 else C j =3.2×Max(CP Ai-j ,CP Bi-j ,CP Ci-j ) (2) Status C of the evaluation point j The numerical result of normally falls within the range of [0,3.2]. If C j The value is 0, then the state of the evaluation point is optimal. j When the value of changes from 0 to 3.2, the status of the evaluation point becomes worse and worse; The weights of the three types of state parameters in formula (2) are Ai , Q Bi and Q Ci The value of gives the rule of formula (3); The first type of state parameter in step 8): macroscopic state parameter CP A1-j , according to the results of macroscopic inspection M A1-j : {no defects found, a small number of suspected defects found, obvious defects found} is defined as shown in formula (4): The first type of state parameter in step 8): surface state parameter CP A2-j , according to the surface flaw detection results M A2-j : {no defects found, surface defects found but eliminated after polishing, surface defects found but still exist after polishing} is defined as shown in formula (5): The second type of state parameter in step 8): lossless state parameter CP B1-j , according to the results of nondestructive testing M B1-j :{Level I, Level II, Level III, Level IV} definition, as shown in formula (6): The second type of state parameter in step 8): tissue state parameter CP B2-j , according to the results of metallographic examination B2-j : {level 1, level 2, level 3, level 4, level 5} is defined as shown in formula (7): The third type of state parameter in step 8): wall thickness state parameter CP C1-j , according to the wall thickness inspection result M C1-j The definition is as shown in formula (8): In formula (8), d0 is the designed wall thickness, in mm; The third type of state parameter in step 8): hardness state parameter CP C2-j , according to the hardness test results M C2-j The definition is as shown in formula (9): The specific operation steps of step 5) are: Identify all assessment points of the assessment object and divide them into: shell assessment point, head assessment point, longitudinal weld assessment point and girth weld assessment point, distinguished by the following subscripts bd, dh, lw and gw respectively.

2. The state assessment method of a supercritical or ultra-supercritical boiler steam-water separator body according to claim 1, characterized in that: The evaluation object of step 1) is the supercritical or ultra-supercritical boiler steam-water separator body, and the basic information includes design drawings, design diameter, design wall thickness, design material, and detailed replacement or repair processing record files.

3. The state assessment method of a supercritical or ultra-supercritical boiler steam-water separator body according to claim 1, characterized in that: The specific operation steps in step 3) are: Based on the stage of the evaluation object identified in step 2), determine its corresponding status factor C S ; According to the design and manufacturing data collected in step 1), the value of S is found according to the following table; 4. The state assessment method of a supercritical or ultra-supercritical boiler steam-water separator body according to claim 1, characterized in that: The specific operation steps of step 6) are: Taking into account the maintenance plan, time and cost, for all the evaluation points determined in step 5), select appropriate items from macro inspection, surface flaw detection, non-destructive testing, metallographic inspection, wall thickness measurement, and hardness inspection to develop and implement a metal inspection plan.

5. The state assessment method of a supercritical or ultra-supercritical boiler steam-water separator body according to claim 1, characterized in that: The specific operation steps of step 7) are: According to the metal inspection items determined in step 6), obtain the metal inspection results of each assessment point, classify the state parameters into three categories according to the metal inspection results, and confirm the state parameters CP and weights Q corresponding to each metal inspection item at each assessment point;

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