A method for evaluating the service life and safety of a water-cooled wall of a coal-fired boiler

Abstract

The application discloses a kind of for coal-fired boiler water-cooled wall life and safety evaluation method, it is related to coal-fired boiler state evaluation field.Solve the problem that prior art cannot be carried out comprehensive evaluation to the service life and safety condition of water-cooled wall.Method includes: the step of calculating the over-temperature degree of water-cooled wall;The step of calculating the wear degree of water-cooled wall region;The step of calculating the creep life value of water-cooled wall pipe outer wall;The step of calculating the corrosion degree of sulfide high-temperature corrosion and sulfide type high-temperature corrosion;The step of calculating the coking degree of water-cooled wall pipe section;The step of calculating the stress influence degree of water-cooled wall pipe;According to water-cooled wall over-temperature degree, water-cooled wall region wear degree, water-cooled wall pipe outer wall creep life value, sulfide high-temperature corrosion and sulfide type high-temperature corrosion corrosion degree, water-cooled wall pipe section coking degree, water-cooled wall pipe stress influence degree and water-cooled wall pipe stress influence degree calculate cold wall life and safety.Application is carried out in water-cooled wall safety evaluation field.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of coal-fired boiler state evaluation, and particularly relates to a method for evaluating the service life and safety of a water-cooled wall of a coal-fired boiler. BACKGROUND

[0002] The combustion in the furnace of a coal-fired boiler is relatively complex, and various risks such as over-temperature, wear, creep, corrosion, coking and stress exist in some areas of the water-cooled wall, which will cause the water-cooled wall to be thinned and cracked, thereby affecting the service life and safety of the water-cooled wall. In actual operation of the boiler, only a limited number of temperature measuring points and H2S gas composition measuring points are provided on the four water-cooled walls for monitoring. Due to the black-box nature of the coal-fired boiler, the information provided by these measuring points is very limited, and the service life and safety of the water-cooled wall cannot be comprehensively evaluated. As a result, the operation personnel of the coal-fired boiler still have to rely on experience to make judgments in actual operation, which is not conducive to the safe and stable operation of the coal-fired unit. In the recent context of deep peak shaving operation, the unit is operated at a low load for a long time, and the load is frequently changed, which brings greater safety risks to the boiler. Therefore, there is an urgent need for a method for comprehensively evaluating the service life and safety of the water-cooled wall. SUMMARY

[0003] The present application is directed to the problem that the prior art cannot comprehensively evaluate the service life and safety of the water-cooled wall. A method for evaluating the service life and safety of the water-cooled wall of a coal-fired boiler is provided, which comprises the following steps:

[0004] a step of calculating the over-temperature degree of the water-cooled wall;

[0005] a step of calculating the wear degree of the water-cooled wall area;

[0006] a step of calculating the creep life value of the outer wall of the water-cooled wall pipe;

[0007] a step of calculating the corrosion degree of sulfide high-temperature corrosion and sulfide type high-temperature corrosion;

[0008] a step of calculating the coking degree of the water-cooled wall pipe section;

[0009] a step of calculating the stress influence degree of the water-cooled wall pipe;

[0010] The service life and safety of the water-cooled wall are calculated according to the over-temperature degree of the water-cooled wall, the wear degree of the water-cooled wall area, the creep life value of the outer wall of the water-cooled wall pipe, the corrosion degree of sulfide high-temperature corrosion and sulfide type high-temperature corrosion, the coking degree of the water-cooled wall pipe section, the stress influence degree of the water-cooled wall pipe and the stress influence degree of the water-cooled wall pipe.

[0011] Further, a preferred mode is provided, wherein the step of calculating the over-temperature degree of the water-cooled wall comprises:

[0012] According to the wall heat load data obtained by CFD numerical simulation, wall temperature of the water cooling wall is calculated according to the wall heat load data and the water dynamic force calculation pipe section water cooling wall material, pipe diameter wall thickness and pipe section outer surface wall temperature.

[0013] According to the wall heat load data obtained by CFD numerical simulation, wall temperature of the water cooling wall is calculated according to the wall heat load data and the water dynamic force calculation pipe section water cooling wall material, pipe diameter wall thickness and pipe section outer surface wall temperature.

[0014] The pipe section outer surface wall temperature is subtracted from the water cooling wall alarm temperature to obtain the current pipe section area water cooling wall over-temperature degree.

[0015] According to the over-temperature degree theoretical maximum value and the theoretical minimum value calculated according to the pipe section material, the pipe section area water cooling wall over-temperature degree is standardized.

[0016] Further, an optimal mode is also proposed, wherein the step of calculating the water cooling wall area wear degree comprises:

[0017] According to the coal powder concentration and particle trajectory data obtained by CFD numerical simulation, the water cooling wall area particle wear degree is calculated according to the coal powder concentration and particle trajectory data and the pipe section water cooling wall material.

[0018] According to the coal powder concentration and particle trajectory data obtained by CFD numerical simulation, the water cooling wall area particle wear degree is calculated according to the coal powder concentration and particle trajectory data and the pipe section water cooling wall material.

[0019] According to the pipe section material and the coal powder flow field, the water cooling wall area particle wear degree theoretical maximum value and the theoretical minimum value are calculated, and the water cooling wall area particle wear degree is standardized.

[0020] Further, an optimal mode is also proposed, wherein the step of calculating the water cooling wall pipe outer wall creep life value comprises:

[0021] According to the water cooling wall pipe outer wall temperature and pressure data calculated by CFD numerical simulation;

[0022] The water cooling wall pipe outer wall temperature and pressure data are combined with the laboratory creep life calculation constant table of different materials;

[0023] The Larson-Miller equation is used to calculate the water cooling wall creep life value at the current average temperature.

[0024] Further, an optimal mode is also proposed, wherein the step of calculating the sulfide high-temperature corrosion and sulfide type high-temperature corrosion corrosion degree comprises:

[0025] According to the H2S online measurement system measurement point data and CFD numerical simulation H2S distribution concentration field data, combined with the wall temperature calculation in the over-temperature degree, the corrosion degree of the current water cooling wall pipe section is obtained.

[0026] Further, an optimal mode is also proposed, wherein the step of calculating the water cooling wall pipe section coking degree comprises:

[0027] Based on the coal quality data of the power plant combustion, a three-dimensional visualization model of the boiler coking is obtained by combining CFD numerical simulation, and the coking degree of the current water-cooled wall pipe section is calculated.

[0028] Further, a preferred mode is also proposed, wherein the step of calculating the stress influence degree of the water-cooled wall pipe comprises:

[0029] According to the methods of thermal calculation, CFD numerical calculation and FEM stress calculation, the heat transfer and stress conditions under the conditions of combustion + convection, radiation + metal heat conduction + gas-solid heat transfer between the working medium and the water-cooled wall pipe are analyzed and studied;

[0030] According to the heat transfer and stress conditions and fatigue calculation, the stress influence degree is calculated.

[0031] Further, a preferred mode is also proposed, wherein the step of calculating the stress influence degree of the water-cooled wall pipe comprises:

[0032] L = λ1C + λ2M + λ3R + λ4F + λ5J + λ6Y

[0033] Wherein, C represents the over-temperature degree of the water-cooled wall pipe section, M represents the wear degree, R represents the creep degree, F represents the corrosion degree, J represents the coking degree, Y represents the stress influence degree, λ i , i = 1, 2, 3, 4, 5, 6 are weight coefficients of each index.

[0034] Based on the same inventive concept, the present application also proposes a computer device comprising a memory and a processor, wherein the memory stores a computer program, and when the processor runs the computer program stored in the memory, the processor executes the method for evaluating the service life and safety of the water-cooled wall of the coal-fired boiler according to any one of the above.

[0035] Based on the same inventive concept, the present application also proposes a computer readable storage medium, wherein the computer readable storage medium stores a computer program, and when the computer program is run by a processor, the steps of the method for evaluating the service life and safety of the water-cooled wall of the coal-fired boiler according to any one of the above are executed.

[0036] The present application has the following advantages:

[0037] 1、The method for evaluating the service life and safety of the water-cooled wall of the coal-fired boiler proposed in the present application fully considers various factors influencing the actual service life and safety of the water-cooled wall of the coal-fired boiler, such as over-temperature, wear, creep, corrosion, coking and stress, can comprehensively and truly reflect the service life loss of the boiler water-cooled wall, and realizes comprehensive analysis and evaluation of various factors.

[0038] 2. The method for evaluating the service life and safety of the water-cooled wall of a coal-fired boiler according to the present application can sort the factors affecting the safety of the current boiler operation based on the index weight, thereby guiding the subsequent operation.

[0039] 3. The method for evaluating the service life and safety of the water-cooled wall of a coal-fired boiler according to the present application can perform instant early warning on the water-cooled wall of the boiler, accurately estimate the service life of the water-cooled wall pipe, remind the power plant maintenance personnel to replace the pipe in time during the shutdown period, reduce the non-stop of the unit, and improve the safety and economy of the operation of the unit.

[0040] The present application is applied to the field of safety evaluation of water-cooled walls. BRIEF DESCRIPTION OF DRAWINGS

[0041] Figure 1 A flow chart of the method for evaluating the service life and safety of the water-cooled wall of a coal-fired boiler according to the first embodiment. DETAILED DESCRIPTION

[0042] In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described in detail below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are some but not all of the embodiments of the present application.

[0043] In the first embodiment, the method for evaluating the service life and safety of the water-cooled wall of a coal-fired boiler comprises the following steps.

[0044] calculating the over-temperature degree of the water-cooled wall;

[0045] calculating the wear degree of the water-cooled wall region;

[0046] calculating the creep life value of the outer wall of the water-cooled wall pipe;

[0047] calculating the corrosion degree of sulfide high-temperature corrosion and sulfide type high-temperature corrosion;

[0048] calculating the coking degree of the water-cooled wall pipe section;

[0049] calculating the stress influence degree of the water-cooled wall pipe;

[0050] calculating the service life and safety of the water-cooled wall based on the over-temperature degree of the water-cooled wall, the wear degree of the water-cooled wall region, the creep life value of the outer wall of the water-cooled wall pipe, the corrosion degree of sulfide high-temperature corrosion and sulfide type high-temperature corrosion, the coking degree of the water-cooled wall pipe section, the stress influence degree of the water-cooled wall pipe, and the stress influence degree of the water-cooled wall pipe.

[0051] In this embodiment, by accurately calculating the over-temperature degree of the water-cooled wall, potential problems caused by high temperature, such as cracks and deformation, can be discovered and evaluated in a timely manner. Considering the wear and tear of different areas of the water-cooled wall helps to determine the parts that need to be focused on, improving the efficiency of maintenance and repair. By calculating the creep life value of the outer wall of the tube, the life of the material in a high-temperature environment can be predicted, which helps to avoid structural loosening or cracking caused by creep. Considering the degree of sulfide and non-sulfide high-temperature corrosion, the durability of the tube wall material in a corrosive environment can be effectively evaluated, and protective measures can be taken in a timely manner. The degree of coking of the water-cooled wall tube section is evaluated to predict the impact of coking on heat exchange efficiency, and measures to prevent coking can be taken in a timely manner. Considering the impact of stress on the water-cooled wall tube wall, including thermal stress and mechanical stress, it helps to prevent cracks and material fatigue caused by stress.

[0052] By considering various factors and combining actual monitoring data, the expected life and safety score of the water-cooled wall can be calculated. This comprehensive evaluation can help operators and managers understand the health of the equipment and take necessary preventive and maintenance measures in a timely manner, thereby reducing the risk of accidents and improving the safety and reliability of the equipment. Through this method, operators can make decisions based on scientific data and algorithms rather than relying solely on experience. This data-driven approach effectively improves the accuracy of evaluation and the precision of prediction, making maintenance and operation strategies more scientific and effective. Especially in challenging operating conditions such as deep peak shaving, the application of this method can better cope with the challenges of rapidly changing loads and frequent start-stop, ensuring the long-term stable operation of the equipment.

[0053] In the second embodiment, the method for evaluating the life and safety of the water-cooled wall of a coal-fired boiler is further limited to the first embodiment. The step of calculating the over-temperature degree of the water-cooled wall includes:

[0054] Obtain wall heat load data from CFD numerical simulation;

[0055] Calculate the water-cooled wall material, tube diameter, wall thickness, and outer surface wall temperature of the tube section based on the wall heat load data and hydrodynamic calculations;

[0056] Subtract the water-cooled wall alarm temperature from the outer surface wall temperature of the tube section to obtain the over-temperature degree of the water-cooled wall in the current tube section area;

[0057] Calculate the theoretical maximum and minimum values of the over-temperature degree based on the tube section material, and perform data standardization processing on the over-temperature degree of the water-cooled wall in the tube section area.

[0058] The CFD numerical simulation used in this embodiment can more accurately obtain the thermal load data of the water-cooled wall surface without relying on simplified models or empirical formulas. This can more accurately simulate the thermal load distribution under actual working conditions, thereby improving the accuracy of the evaluation. By calculating the material, pipe diameter, wall thickness, and outer surface wall temperature of the water-cooled wall of the pipe section through hydrodynamic calculation, multiple key parameters of the water-cooled wall structure are considered, making the evaluation more comprehensive and systematic. The degree of water-cooled wall overheating in the pipe section area can be obtained in a timely manner, reflecting the actual situation under the current operating state. This real-time nature allows for quick action when necessary to ensure the safe operation of the equipment. By standardizing the data of the overheating degree, it is more convenient to compare and analyze under different conditions, providing more intuitive and operable evaluation results.

[0059] Embodiment three, this embodiment is a further limitation of the method for evaluating the service life and safety of the water-cooled wall of a coal-fired boiler according to embodiment one, wherein the step of calculating the wear degree of the water-cooled wall region comprises:

[0060] obtaining coal powder concentration and particle trajectory data according to CFD numerical simulation;

[0061] calculating the particle wear degree of the water-cooled wall region according to the coal powder concentration and particle trajectory data and the material of the water-cooled wall of the pipe section;

[0062] calculating the theoretical maximum and minimum values of the particle wear degree of the water-cooled wall region according to the material of the pipe section and the coal powder flow field, and standardizing the data of the particle wear degree of the water-cooled wall region.

[0063] This embodiment obtains coal powder concentration and particle trajectory data through CFD numerical simulation, and combines with the material information of the water-cooled wall of the pipe section, to accurately calculate the particle wear degree of the water-cooled wall region. This method not only considers the existence and distribution of particles, but also analyzes the actual impact of particles on the material of the water-cooled wall, making the evaluation more realistic and comprehensive. By calculating the theoretical maximum and minimum values of the particle wear degree under the condition of the material of the pipe section and the coal powder flow field, the wear of the water-cooled wall can be evaluated in a range. This can better understand the possible extreme conditions of wear, and provide a basis for developing preventive measures and maintenance plans. Standardizing the data of the particle wear degree of the water-cooled wall region makes the evaluation results under different conditions comparable. This standardization can help operators or engineers more intuitively understand the wear degree, and help them make timely decisions and adjustments. Since the coal powder concentration, particle trajectory, and water-cooled wall material are considered, this method has strong predictability and responsiveness. Using this method can foresee possible wear conditions, so that preventive measures can be taken in advance to avoid equipment damage or increased downtime.

[0064] Embodiment four, the embodiment is one kind for coal-fired boiler water wall life and safety evaluation method of further limitation to the method for evaluating the life and safety of the water wall of a coal-fired boiler described in embodiment one, the step of calculating the creep life value of the outer wall of the water wall pipe comprises:

[0065] According to the water wall pipe outer wall temperature and pressure data calculated by CFD numerical simulation;

[0066] Water wall pipe outer wall temperature and pressure data combined with laboratory creep life calculation constant table of different materials;

[0067] The Larson-Miller equation is used to calculate the creep life value of the water wall at the current average temperature.

[0068] The water wall pipe outer wall temperature and pressure data calculated by CFD numerical simulation can more accurately reflect the temperature and stress state of the pipe outer wall under actual working conditions. Such data is more realistic and accurate, which helps to accurately evaluate the creep life. Combined with the laboratory creep life calculation constant table, the creep characteristics and durability of different materials are considered, and the creep life of the water wall can be quantitatively evaluated according to the specific material selection. This method can more accurately predict the creep behavior of different materials under actual operating conditions. The Larson-Miller equation is used to calculate the creep life value of the water wall at the current average temperature, which combines the effects of temperature and time to give the predicted value of the creep life. Make the evaluation more comprehensive and reliable. This comprehensive analysis capability not only improves the scientificity of the evaluation, but also enhances the comprehensive understanding of the life and safety of the water wall.

[0069] Embodiment five, the embodiment is one kind for coal-fired boiler water wall life and safety evaluation method of further limitation to the method for evaluating the life and safety of the water wall of a coal-fired boiler described in embodiment one, the step of calculating the creep life value of the outer wall of the water wall pipe comprises:

[0070] According to the H2S online measurement system measurement point data and CFD numerical simulation H2S distribution concentration field data, combined with wall temperature calculation in over-temperature degree, the corrosion degree of the current water wall pipe section is obtained.

[0071] The measurement point data obtained by the H2S online measurement system in this embodiment can monitor the concentration distribution of H2S in the coal-fired boiler in real time. Combined with the H2S distribution concentration field data obtained by CFD numerical simulation, the H2S concentration distribution in the water wall pipe section can be more accurately understood, so as to accurately evaluate the possibility and degree of sulfide high-temperature corrosion and sulfide type high-temperature corrosion.

[0072] By combining the wall temperature calculation in the superheat degree, the actual temperature state of the pipe wall can be considered. This comprehensive analysis not only considers the distribution of corrosive agents such as H2S, but also considers the importance of temperature on the corrosion of water-cooled wall pipes, so the evaluation results are more comprehensive and reliable.

[0073] By accurately assessing the corrosion degree of sulfide high-temperature corrosion and sulfide high-temperature corrosion, potential problems can be forewarned, and corresponding maintenance plans and measures can be developed. This preventive maintenance guidance can greatly reduce the risk of accidents and downtime, and improve the safety and reliability of the boiler.

[0074] Based on the measured data and numerical simulation results, this method provides scientific data support to help decision-makers make more accurate and effective operation and maintenance management. This decision support helps optimize the operation efficiency of the equipment, prolong the service life of the water-cooled wall, and helps avoid potential environmental pollution risks.

[0075] Embodiment six, this embodiment is a further limitation of the method for evaluating the service life and safety of the water-cooled wall of a coal-fired boiler described in embodiment one, the step of calculating the coking degree of the water-cooled wall pipe section, comprising:

[0076] Based on the coal quality data of the power plant and the CFD numerical simulation, a three-dimensional visualization model of boiler coking is obtained, and the coking degree of the current water-cooled wall pipe section is calculated.

[0077] Through analysis based on coal quality data of the power plant, combined with CFD numerical simulation, the influence of coal quality on the coking process of the boiler can be more comprehensively understood. The characteristics of different coal types (such as ash content, volatile content, etc.) have important influence on the coking process, and through this method, the coking degree of the water-cooled wall pipe section can be more accurately evaluated.

[0078] The three-dimensional visualization model of boiler coking obtained by CFD numerical simulation can directly display the distribution of coking in the water-cooled wall pipe section. This visualization model not only helps engineers and operators understand the spatial distribution characteristics of coking, but also helps determine the most serious coking area, so that targeted cleaning and maintenance strategies can be developed.

[0079] Compared with traditional empirical methods or simplified models, the use of CFD numerical simulation can more accurately simulate the fluid and heat transfer process in the boiler, thereby more accurately predicting the degree and location of coking. This high-precision calculation helps to discover possible coking problems in a timely manner and take preventive measures to avoid equipment damage or downtime caused by coking.

[0080] By monitoring and periodically evaluating the coking condition of the water-cooled wall tube section in real time, effective preventive maintenance plans can be developed. These plans include regular cleaning and inspection to ensure the efficient operation of the water-cooled wall and extend its service life.

[0081] Embodiment seven, this embodiment is a further limitation of the method for evaluating the service life and safety of the water-cooled wall of a coal-fired boiler according to embodiment one, wherein the step of calculating the degree of stress influence on the water-cooled wall tube comprises:

[0082] According to the methods of thermal calculation, CFD numerical calculation and FEM stress calculation, the heat transfer and stress conditions under the conditions of combustion + convection, radiation + metal heat conduction + gas-solid heat transfer between the working medium and the water-cooled wall tube are analyzed and studied;

[0083] According to the heat transfer and stress conditions and fatigue calculation, the degree of stress influence is calculated.

[0084] By combining thermal calculation, CFD numerical calculation and finite element method (FEM) stress calculation, multi-physical field coupling analysis can be realized. The coal-fired boiler water-cooled wall is affected by multiple forces such as combustion, convection, radiation, metal heat conduction and gas-solid heat transfer between the working medium and the water-cooled wall tube during operation. The comprehensive effect of these factors has a complex influence on the heat transfer and stress conditions of the water-cooled wall tube. By considering these influencing factors comprehensively, the stress conditions of the water-cooled wall tube can be more accurately simulated and evaluated.

[0085] CFD numerical calculation can be used to simulate the fluid flow conditions during combustion and gas-solid heat transfer, including the complex interaction of thermal flow, convection and radiation heat transfer. This detailed heat transfer simulation helps to accurately determine the temperature distribution of the water-cooled wall tube wall, so as to more accurately calculate the stress distribution and influence degree.

[0086] By applying FEM for stress calculation, the stress distribution of the water-cooled wall tube under operating conditions can be calculated based on the actual heat transfer conditions and material properties. Combined with the heat transfer simulation results and material fatigue performance data, the specific influence degree of the water-cooled wall tube under stress can be quantified and evaluated. This method not only can detect potential stress concentration areas, but also can predict possible fatigue damage risks, which helps to take necessary maintenance and repair measures in advance.

[0087] By accurately evaluating the stress influence degree of the water-cooled wall tube, more detailed and effective maintenance strategies can be developed. These strategies include regular inspection, reinforcement and repair measures to ensure the safe operation of the water-cooled wall and extend its service life.

[0088] Combining thermal calculation, CFD numerical calculation and FEM stress calculation, the comprehensive analysis provides scientific data support and decision basis for management and engineers. The decision support helps to optimize the boiler operation management strategy and improve the reliability and safety of the equipment.

[0089] Embodiment eight, the embodiment is a further limitation of the method for evaluating the service life and safety of the water-cooled wall of a coal-fired boiler according to embodiment one, wherein the calculation of the service life and safety of the water-cooled wall comprises:

[0090] L = λ1C + λ2M + λ3R + λ4F + λ5J + λ6Y

[0091] wherein C represents the over-temperature degree of the water-cooled wall pipe section, M represents the wear degree thereof, R represents the creep degree thereof, F represents the corrosion degree thereof (mainly H2S), J represents the coking degree thereof, and Y represents the stress influence degree thereof, λ i , i = 1, 2, 3, 4, 5, 6 are weight coefficients of the indexes.

[0092] Embodiment nine, the computer device according to the embodiment comprises a memory and a processor, and the memory stores a computer program, wherein when the processor runs the computer program stored in the memory, the processor executes the method for evaluating the service life and safety of the water-cooled wall of a coal-fired boiler according to any one of embodiments one to eight.

[0093] Embodiment ten, the computer readable storage medium according to the embodiment stores a computer program, and when the processor runs the computer program, the processor executes the steps of the method for evaluating the service life and safety of the water-cooled wall of a coal-fired boiler according to any one of embodiments one to eight.

[0094] The method is mainly based on the service life and safety evaluation index L of the water-cooled wall, and the calculation method is as follows:

[0095] L = λ1C + λ2M + λ3R + λ4F + λ5J + λ6Y

[0096] wherein C represents the over-temperature degree of the water-cooled wall pipe section, M represents the wear degree thereof, R represents the creep degree thereof, F represents the corrosion degree thereof (mainly H2S), J represents the coking degree thereof, and Y represents the stress influence degree thereof, λ i (i = 1, 2, 3, 4, 5, 6) are weight coefficients of the indexes.

[0097] The calculation method of C (over-temperature degree): the local over-temperature of the water wall during the boiler load change is an important factor affecting the service life of the pipe, the wall heat load data are obtained through the CFD numerical simulation, and the water power calculation and the pipe diameter, wall thickness and other information of the water wall material of the pipe section are combined to calculate the pipe outer surface wall temperature, and the difference between the wall temperature and the water wall alarm temperature is obtained to obtain the over-temperature degree of the water wall in the region. The theoretical maximum and minimum values of the over-temperature degree based on the pipe material are calculated, and the data are standardized to convert them into values in the interval (0, 1), and the standardization method is

[0098]

[0099] wherein C is the standardized over-temperature degree, C1 is the over-temperature degree calculated based on the CFD heat load data and the pipe wall material, C max and C min are the theoretical maximum and minimum values of the over-temperature degree calculated based on the pipe material, and the standardization methods of M, R, F, J and Y are the same and will not be repeated.

[0100] The calculation method of M (abrasion degree): the water wall region abrasion often occurs in the burner region, and the direct scouring of the unburned coal particles (ash-containing gas flow) on the water wall is the main cause of the abrasion, the coal particle concentration and particle trajectory data are obtained through the CFD numerical simulation, and the particle abrasion degree is calculated in combination with the water wall material of the pipe section. The theoretical maximum and minimum values are calculated based on the pipe material and the coal flow field, and the data are standardized to convert them into values in the interval (0, 1).

[0101] The calculation method of R (creep degree): the water wall pipe outer wall temperature and pressure data calculated through the CFD numerical simulation are combined with the laboratory creep life calculation constant table of different materials to calculate the creep life value of the water wall at the current average temperature by using the Larson-Miller equation. The theoretical maximum and minimum values are calculated based on the pipe material, and the data are standardized to convert them into values in the interval (0, 1).

[0102] The calculation method of F (corrosion degree): only the high-temperature corrosion caused by the reducing gas and the sulfide high-temperature corrosion are considered here. The sulfide high-temperature corrosion is mainly divided into the high-temperature corrosion caused by the atomic state [S] and H2S gas. Based on the measured point data of the H2S online measurement system and the H2S distribution concentration field data calculated through the CFD numerical simulation, the wall temperature calculation in the above C (over-temperature degree) is combined to obtain the corrosion degree of the current water wall pipe section. The theoretical maximum and minimum values are calculated based on the pipe material and the sulfur content in the coal used in the power plant, and the data are standardized to convert them into values in the interval (0, 1).

[0103] The calculation method of J (coking degree): Coking involves the processes of coal combustion, heat transfer in the furnace, coking characteristics of coal quality, movement of coal ash particles in the furnace, and adhesion between coal ash and the tube wall, etc. Based on the data of coal quality used in power plants combined with CFD numerical simulation, a three-dimensional visualization model of boiler coking is obtained to comprehensively show the coking state in the furnace and calculate the coking degree of the current water-cooled wall tube section. The theoretical maximum and minimum values are calculated based on the tube material and the data of coal quality used in power plants, and the data is standardized to be converted into a value in the interval (0, 1).

[0104] The calculation method of Y (stress influence degree): Since the water-cooled wall crack is a fatigue crack, it is mainly caused by the fatigue factor caused by temperature alternation. Therefore, the alternation of water-cooled wall tube metal temperature and stress is the direct cause of fatigue. The method of conventional thermodynamic calculation + CFD numerical calculation + FEM stress calculation is adopted for analysis to study the heat transfer and stress under the condition of replicated heat transfer of combustion + convection, radiation + metal heat conduction + gas-solid heat transfer between working medium and water-cooled wall tube, reveal the mechanism of causing water-cooled wall temperature alternation and producing alternating stress, and calculate the stress influence degree combined with fatigue calculation. The theoretical maximum and minimum values are calculated based on the tube material and operating temperature and pressure, and the data is standardized to be converted into a value in the interval (0, 1).

[0105] λ i (i = 1, 2, 3, 4, 5, 6) are real numbers in the interval (0, 1), which are selected according to expert experience and actual operation, for example, if the tube section often over-temperature in actual operation, the parameter λ1 corresponding to the over-temperature degree is larger, if the flow field in the furnace is not good, the parameter λ2 corresponding to the particle wear degree is larger, if the boiler frequently changes load during operation, the parameters λ3 and λ6 corresponding to creep and stress influence are larger.

[0106] When the boiler is shut down, the wall thickness of the water-cooled wall tube can be measured by artificial or robotic means, and the wall thickness thinning rate between two shutdowns can be used to represent the damage of the tube section during this period of operation. The wall thickness thinning rate calculation formula is as follows:

[0107]

[0108] Wherein, V represents the wall thickness thinning rate between two shutdowns, L1 is the wall thickness of the tube section measured at the last shutdown, L2 is the wall thickness of the tube section measured at this shutdown, and t is the interval time between two shutdowns.

[0109] The tube wall thinning rate can be used to represent the tube life and safety. The faster the tube thins, the shorter the life and the lower the safety, and the more prone to accidents such as tube burst. Combined with the measured tube wall thinning rate, the parameters λ i (i = 1, 2, 3, 4, 5, 6) selected according to experience and operation data are calibrated and calibrated, and at the same time, λ i(i = 1, 2, 3, 4, 5, 6) represents the weight of each damage such as corrosion, wear and creep on the life and safety of the pipe, and the largest weight is the factor that has the greatest impact on the current pipe segment life and safety.

[0110] Traditionally, the evaluation method for coal-fired boiler water wall is often limited to the analysis of single or partial parameters, such as over-temperature condition or creep life. The present application includes multiple key factors such as over-temperature degree, wear degree, creep life, high-temperature corrosion degree, coking degree and stress effect in the evaluation system, thereby realizing comprehensive evaluation of the water wall. By calculating and comprehensively analyzing the effects of different factors, including physical wear, chemical corrosion and structural stress of the pipe wall, the present application can more accurately predict the life and safety of the water wall. This comprehensive analysis method makes the evaluation of the water wall under complex working conditions more reliable and accurate.

[0111] Traditional evaluation methods often fail to comprehensively consider the combined effects of multiple factors during the operation of the water wall, such as the influence of stress on the pipe wall and the creep effect under high-temperature environment. The present application overcomes the limitations of traditional evaluation methods by introducing advanced calculation methods and models, thereby improving the reliability and practicality of the evaluation results.

[0112] The method of the present application not only provides detailed analysis of various damages and influencing factors of the water wall, but also can dynamically adjust and optimize the evaluation according to real-time data and historical data, thereby improving the safety and efficiency of the boiler operation. This comprehensive evaluation method has important application prospects in industrial production, which can effectively prolong the service life of the equipment, reduce maintenance costs, and improve production efficiency and safety.

[0113] Those skilled in the art will understand that the embodiments of the present disclosure can be provided as a method, a system or a computer program product. Therefore, the present disclosure can take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Moreover, the present disclosure can take the form of a computer program product implemented on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0114] The present disclosure is described with reference to flowcharts and / or block diagrams of methods, devices (systems) and computer program products according to embodiments of the present disclosure. It should be understood that each flow and / or block in the flowcharts and / or block diagrams, as well as combinations of flows and / or blocks in the flowcharts and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a general-purpose computer, a special-purpose computer, an embedded processor or other programmable data processing apparatus to produce a machine, so that the instructions executed by the computer or other programmable data processing apparatus produce a device that implements the flowcharts and / or block diagrams. Figure 1apparatuses that implement the functions specified in the flowchart or flowcharts and / or blocks Figure 1 These computer program instructions can also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instructions which implement the flowchart or flowcharts and / or blocks Figure 1 These computer program instructions can also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instructions which implement the flowchart or flowcharts and / or blocks Figure 1 These computer program instructions can also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instructions which implement the flowchart or flowcharts and / or blocks

[0115] These computer program instructions can also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the flowchart or flowcharts and / or blocks Figure 1 These computer program instructions can also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instructions which implement the flowchart or flowcharts and / or blocks Figure 1 These computer program instructions can also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instructions which implement the flowchart or flowcharts and / or blocks

[0116] Finally, it should be noted that the above embodiments are merely used to illustrate the technical solutions of the present disclosure, rather than limiting the scope of protection of the present disclosure. Although the present disclosure has been described in detail with reference to the above embodiments, those skilled in the art should understand that after reading the present disclosure, they can make various changes, modifications or equivalent replacements to the specific embodiments. However, these changes, modifications or equivalent replacements still fall within the scope of protection of the appended claims.

Claims

1. A method for evaluating the life and safety of a water-cooled wall of a coal-fired boiler, characterized by, The method comprises: a step of calculating the over-temperature degree of the water wall; a step of calculating the wear degree of the water wall area; a step of calculating the creep life value of the outer wall of the water wall tube; a step of calculating the corrosion degree of sulfide high-temperature corrosion and sulfide type high-temperature corrosion; a step of calculating the coking degree of the water wall tube section; a step of calculating the stress-affected degree of the water wall tube; calculating the water wall life and safety according to the over-temperature degree of the water wall, the wear degree of the water wall area, the creep life value of the outer wall of the water wall tube, the corrosion degree of sulfide high-temperature corrosion and sulfide type high-temperature corrosion, the coking degree of the water wall tube section, the stress-affected degree of the water wall tube and the stress-affected degree of the water wall tube; the step of calculating the over-temperature degree of the water wall comprises: obtaining wall heat load data according to CFD numerical simulation; calculating the water wall tube section material, pipe diameter, wall thickness and outer surface wall temperature according to the wall heat load data and water dynamics; obtaining the current water wall over-temperature degree of the tube section area by subtracting the water wall alarm temperature from the outer surface wall temperature of the tube section; calculating the theoretical maximum value and the theoretical minimum value of the over-temperature degree according to the tube section material, and performing data standardization processing on the water wall over-temperature degree of the tube section area; the step of calculating the wear degree of the water wall area comprises: obtaining coal dust concentration and particle trajectory data according to CFD numerical simulation; calculating the water wall area particle wear degree according to the coal dust concentration and particle trajectory data and the water wall tube section material; calculating the theoretical maximum value and the theoretical minimum value of the water wall area particle wear degree according to the tube section material and the coal dust flow field, and performing data standardization processing on the water wall area particle wear degree; the step of calculating the creep life value of the outer wall of the water wall tube comprises: water wall tube outer wall temperature and pressure data obtained by CFD numerical simulation; water wall tube outer wall temperature and pressure data combined with a laboratory creep life calculation constant table of different materials; calculating the creep life value of the water wall at the current average temperature by using the Larson-Miller equation.

2. A method for evaluating the service life and safety of a water-cooled wall of a coal-fired boiler according to claim 1, characterized in that, the step of calculating the corrosion degree of sulfide high-temperature corrosion and sulfide type high-temperature corrosion comprises: obtaining the corrosion degree of the current water wall tube section by combining the wall temperature calculation in the over-temperature degree according to the measurement point data of the H2S online measurement system and the H2S distribution concentration field data of the CFD numerical simulation.

3. A method for evaluating the service life and safety of a water-cooled wall of a coal-fired boiler according to claim 1, characterized in that, the step of calculating the coking degree of the water wall tube section comprises: calculating the coking degree of the current water wall tube section based on the coal quality data of the power plant combined with the CFD numerical simulation to obtain a three-dimensional visualization model of boiler coking.

4. The method for evaluating the service life and safety of a water-cooled wall of a coal-fired boiler according to claim 1, characterized in that, the step of calculating the stress-affected degree of the water wall tube comprises: analyzing and researching the heat transfer and stress under the conditions of replicated heat transfer of combustion + convection, radiation + metal heat conduction + gas-solid heat transfer of the working medium and the water wall tube according to the methods of thermal calculation, CFD numerical calculation and FEM stress calculation; calculating the stress-affected degree according to the heat transfer and stress and fatigue calculation.

5. A method for evaluating the service life and safety of a water-cooled wall of a coal-fired boiler according to claim 1, characterized in that, the calculation of the water wall life and safety comprises: Wherein, C represents the over-temperature degree of the water-cooled wall pipe section, M represents the wear degree thereof, R represents the creep degree thereof, F represents the corrosion degree thereof, J represents the coking degree thereof, and Y represents the stress influence degree thereof, is a weight coefficient of each index.

6. A computer device, comprising: The application relates to a computer program product for a method for evaluating the service life and safety of a water-cooled wall of a coal-fired boiler, comprising a memory and a processor, wherein the memory stores a computer program, and when the processor runs the computer program stored in the memory, the processor executes the method for evaluating the service life and safety of a water-cooled wall of a coal-fired boiler according to any one of claims 1-5.

7. A computer-readable storage medium, characterized in that, The computer readable storage medium stores a computer program, and when the computer program is run by a processor, the steps of the method for evaluating the service life and safety of a water-cooled wall of a coal-fired boiler according to any one of claims 1-5 are executed.

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