Method, system and equipment for calculating resistance of coal pipeline in thermal power plant

Abstract

The application provides a method, system and equipment for calculating the resistance of a coal pipeline in a thermal power plant. The method comprises: collecting the structural parameters of each coal pipeline in a target coal pulverizing system, and obtaining the operating state data and coal quality characteristic data of each coal pipeline under the current working condition; inputting the structural parameters and operating state data of each coal pipeline into a preset gas-solid two-phase flow dynamics model, combining the coal flow pattern boundary result calculated according to the operating state data, and calculating the gas-solid two-phase resistance along the pipeline and the local resistance under the current suspension state; obtaining the historical cumulative operating data of each coal pipeline, combining the coal quality characteristic data, and calculating the current pipe wall roughness correction value of each coal pipeline through a pipe wall wear evolution model; constructing the wind network topology structure of the target coal pulverizing system, jointly and cooperatively solving the initial resistance drop of each coal pipeline, and outputting the calibrated resistance calculation result of each coal pipeline.

Description

Technical Field

[0001] This application relates to the field of transportation capacity scheduling technology, and in particular to a method, system and equipment for calculating the resistance of pulverized coal pipelines in thermal power plants. Background Technology

[0002] As thermal power equipment develops towards larger capacity, higher parameters, and deeper peak shaving, the operational stability and economy of boiler pulverizing systems place higher demands on the safe and efficient operation of the entire plant. During boiler operation in thermal power plants, pulverized coal pipelines, as key transport channels connecting the coal mill and burners, directly affect the balance of air-coal distribution among burners due to their internal gas-solid two-phase flow resistance characteristics. Uneven air-coal distribution not only leads to deteriorated boiler combustion, localized overheating, or coking, but can also cause serious safety accidents such as pulverized coal accumulation, blockage, or even pipe rupture in the pipelines. Therefore, accurately acquiring and real-time monitoring the resistance status of pulverized coal pipelines is of great significance for optimizing boiler combustion control, achieving air-coal balance regulation, and ensuring the safety of the pulverizing system.

[0003] In related technologies, the acquisition of resistance in pulverized coal pipelines in thermal power plants mainly relies on empirical formulas estimated during the design phase, or on periodic offline testing using manually installed pressure measuring points under specific operating conditions. However, empirical formulas typically assume ideal single-phase flow or steady gas-solid flow inside the pipeline, failing to accurately reflect the nonlinear effects of fluctuations in pulverized coal concentration, changes in coal quality, and frequent adjustments in primary air temperature and volume on resistance during actual operation. Furthermore, traditional offline testing methods suffer from data lag and incomplete coverage of operating conditions. Additionally, pulverized coal pipelines are prone to internal wall wear and localized dust accumulation due to high-concentration dust erosion during long-term operation, leading to dynamic evolution of actual resistance characteristics. Existing technologies struggle to achieve real-time, high-precision continuous measurement of pulverized coal pipeline resistance under complex and variable peak-shaving conditions, thus failing to provide timely and effective resistance feedback data for intelligent combustion optimization in thermal power plants. Summary of the Invention

[0004] In view of this, it is necessary to provide a method, system and equipment for calculating the resistance of pulverized coal pipelines in thermal power plants, which can at least overcome one of the above-mentioned defects.

[0005] In a first aspect, embodiments of this application provide a method for calculating the resistance of pulverized coal pipelines in thermal power plants, the method comprising:

[0006] Collect the structural parameters of each pulverized coal pipeline in the target pulverizing system, and obtain the operating status data and coal quality characteristic data of each pulverized coal pipeline under the current working conditions;

[0007] The structural parameters and operating status data of each pulverized coal pipeline are input into a preset gas-solid two-phase flow dynamics model. Combined with the pulverized coal flow pattern definition results derived from the operating status data, the basic values ​​of the gas-solid two-phase friction resistance and the basic values ​​of the local resistance of each pulverized coal pipeline under the current suspension state are calculated.

[0008] The historical cumulative operating data of each of the pulverized coal pipelines is obtained, and the current pipe wall roughness correction value of each of the pulverized coal pipelines is calculated by combining the coal quality characteristic data and the pipe wall wear evolution model.

[0009] Using the current pipe wall roughness correction value and the coal powder concentration calculated from the operating status data, the friction resistance base value and local resistance base value of each coal powder pipeline are nonlinearly coupled and corrected to obtain the corrected resistance coefficient of each coal powder pipeline under the current operating conditions.

[0010] Based on the corrected resistance coefficient and operating status data of each pulverized coal pipeline, the initial resistance drop of each pulverized coal pipeline is initially calculated.

[0011] The air network topology of the target pulverizing system is constructed. Using the pressure field data of each pulverized coal pipeline outlet and the total air volume conservation constraint of the pulverizing system, the initial resistance drop of each pulverized coal pipeline is solved jointly and collaboratively, and the calibrated resistance calculation results of each pulverized coal pipeline are output.

[0012] In one embodiment, the calculation of the basic values ​​of the gas-solid two-phase friction resistance and the basic values ​​of the local resistance of each of the pulverized coal pipelines in the current suspension state includes:

[0013] Obtain the primary air volume, primary air temperature, and coal feed rate from the operating status data, and calculate the current cross-sectional average wind speed and solid-gas mass ratio in each of the pulverized coal pipelines.

[0014] The motion pattern of pulverized coal particles in the pipeline is determined by the average wind speed and solid-gas mass ratio of the current cross section. When the motion pattern is a non-uniform suspended flow, a gas-solid phase change sedimentation correction factor is introduced through the pulverized coal flow pattern definition result. The single-phase air resistance base value calculated based on the structural parameters is nonlinearly superimposed to obtain the gas-solid two-phase friction resistance base value and local resistance base value of each pulverized coal pipeline in the current suspended state.

[0015] In one embodiment, the step of using the current pipe wall roughness correction value and the coal powder concentration calculated from the operating status data to perform nonlinear coupling correction on the baseline values ​​of the friction resistance and local resistance of each coal powder pipeline, to obtain the corrected resistance coefficient of each coal powder pipeline under the current operating conditions, includes:

[0016] The real-time coal powder concentration in each of the coal powder pipelines is calculated using the solid-gas mass ratio.

[0017] The real-time coal powder concentration, the current pipe wall roughness correction value, and the motion flow pattern are input into the resistance coefficient correction model to calculate the first correction coefficient of pipe wall roughness and coal powder particle collision friction on the frictional resistance, and the second local resistance correction coefficient of high-concentration coal powder at elbows and valves.

[0018] The first correction coefficient and the second local resistance correction coefficient are multiplied by the basic values ​​of the gas-solid two-phase friction resistance and local resistance, respectively, to obtain the corrected resistance coefficients for each of the pulverized coal pipelines under the current operating conditions.

[0019] In one embodiment, the construction of the air network topology of the target pulverizing system involves using the outlet pressure field data of each pulverized coal pipeline and the total air volume conservation constraint of the pulverizing system to jointly and collaboratively solve the initial resistance drop of each pulverized coal pipeline, and outputting the final calibrated resistance calculation results of each pulverized coal pipeline, including:

[0020] Each of the pulverized coal pipelines is taken as a branch of the air network, and an air network topology matrix including the inlet node of the pulverizing system and the outlet nodes of each pipeline is constructed.

[0021] Calculate the initial resistance drop of each of the pulverized coal pipeline branches based on the corrected resistance coefficient and the current average wind speed at the cross section.

[0022] Using the real-time pressure difference at the outlet nodes of each pulverized coal pipeline as the boundary condition, and combining the conservation equations of the total air volume of the pulverizing system and the air volume of each branch, the topology matrix of the air network is iteratively solved. The initial resistance drop is dynamically calibrated using the obtained air volume distribution deviation value, and the final calibrated resistance calculation results of each pulverized coal pipeline are output.

[0023] In one embodiment, the step of acquiring the historical cumulative operating data of each of the pulverized coal pipelines and, in conjunction with the coal quality characteristic data, calculating the current pipe wall roughness correction value of each of the pulverized coal pipelines using a pipe wall wear evolution model includes:

[0024] Extract the cumulative operating time and historical average wind speed of each pulverized coal pipeline from the historical cumulative operating data, and obtain the ash content and hardness index of pulverized coal from the coal quality characteristic data;

[0025] Based on the cumulative operating time, historical average wind speed, pulverized coal ash content and hardness index, calculate the cumulative metal erosion wear of the inner wall of each pulverized coal pipeline;

[0026] The cumulative metal erosion wear is mapped to the pipe wall micromorphology evolution curve, and the current pipe wall roughness correction value that matches the current cumulative wear state of each pulverized coal pipeline is calculated.

[0027] In one embodiment, the step of using the current pipe wall roughness correction value and the coal powder concentration calculated from the operating status data to perform nonlinear coupling correction on the baseline values ​​of the friction resistance and local resistance of each coal powder pipeline, to obtain the corrected resistance coefficient of each coal powder pipeline under the current operating conditions, includes:

[0028] The current pipe wall roughness correction value is input into the anti-wear lining spalling discrimination model to determine the local abrupt roughness of the pipe wall of each of the pulverized coal pipelines;

[0029] When the local abrupt roughness of the pipe wall exceeds the preset abrupt threshold, the coal powder concentration estimated by combining the operating status data is used to calculate the local eddy current resistance increment of the pipe wall. The local eddy current resistance increment of the pipe wall is then superimposed on the nonlinear coupling correction process of the friction resistance base value and the local resistance base value to obtain the corrected resistance coefficient of each coal powder pipeline under the current operating condition.

[0030] In one embodiment, the method further includes:

[0031] Based on the resistance calculation results of each pulverized coal pipeline after calibration, calculate the resistance deviation value between each pulverized coal pipeline and the resistance change rate of a single pulverized coal pipeline within a set time window.

[0032] The resistance deviation value is compared with a preset air-powder imbalance threshold. When the resistance deviation value exceeds the preset air-powder imbalance threshold, the air-powder distribution imbalance state of the target pulverizing system is determined.

[0033] Simultaneously, the resistance change rate is compared with a preset critical threshold for dust accumulation and blockage. When the resistance change rate exceeds the preset critical threshold for dust accumulation and blockage, the coal pulverized pipe with abnormal resistance is located and a dust accumulation and blockage warning signal is output.

[0034] In one embodiment, the method further includes:

[0035] After outputting the resistance calculation results of each pulverized coal pipeline after calibration, the actual measured pressure drop at the outlet of each pulverized coal pipeline is obtained;

[0036] Calculate the residual value between the calibrated resistance measurement result and the actual measured pressure drop;

[0037] When the residual value exceeds the preset deviation threshold, the residual value is used to perform reverse gradient updates on the flow resistance coefficient in the preset gas-solid two-phase flow dynamics model and the wear rate parameter in the pipe wall wear evolution model.

[0038] Secondly, embodiments of this application provide a system for calculating the resistance of pulverized coal pipelines in thermal power plants, applied to implement the method described in the first aspect, the system comprising:

[0039] The data acquisition module is used to collect the structural parameters of each coal powder pipeline in the target pulverizing system, and to obtain the operating status data and coal quality characteristic data of each coal powder pipeline under the current working conditions.

[0040] The basic resistance calculation module is used to input the structural parameters and operating status data of each pulverized coal pipeline into a preset gas-solid two-phase flow dynamics model, and calculate the basic value of the gas-solid two-phase friction resistance and the basic value of the local resistance of each pulverized coal pipeline in the current suspension state.

[0041] The wear correction module is used to acquire the historical cumulative operating data of each of the pulverized coal pipelines, and combine the coal quality characteristic data to calculate the current pipe wall roughness correction value of each of the pulverized coal pipelines through the pipe wall wear evolution model.

[0042] The dynamic coupling correction module is used to perform nonlinear coupling correction on the basic values ​​of friction resistance and local resistance of each of the coal powder pipelines by using the current pipe wall roughness correction value and the coal powder concentration calculated by the operating status data, so as to obtain the correction resistance coefficient of each of the coal powder pipelines under the current operating conditions.

[0043] The initial resistance calculation module is used to calculate the initial resistance drop of each pulverized coal pipeline based on the corrected resistance coefficient and operating status data of each pulverized coal pipeline.

[0044] The wind network collaborative solution module is used to construct the wind network topology of the target pulverizing system. It uses the pressure field data of each pulverized coal pipeline outlet and the total air volume conservation constraint of the pulverizing system to jointly solve the initial resistance drop of each pulverized coal pipeline and output the calibrated resistance calculation results of each pulverized coal pipeline.

[0045] Thirdly, embodiments of this application provide an electronic device, including:

[0046] Processor; and

[0047] A memory having computer-readable instructions stored thereon for controlling the processor to perform the method as described in the first aspect.

[0048] This application provides a method, system, and equipment for calculating the resistance of pulverized coal pipelines in thermal power plants. By deeply integrating a gas-solid two-phase flow dynamics model, a pipe wall wear evolution model, and a system-level air network topology solution, it overcomes the data lag and accuracy deviation problems caused by traditional methods relying solely on empirical formulas or offline single-phase flow tests. By introducing the pulverized coal flow pattern definition results, it achieves an accurate characterization of the gas-solid two-phase suspension state inside the pipeline. Combined with a wear evolution model constructed based on historical operating data and coal quality characteristics, it dynamically corrects the long-term evolutionary impact of pipe wall roughness on resistance. Furthermore, by using the total air volume conservation constraint of the pulverizing system and outlet pressure field data to construct an air network topology structure for joint collaborative solution, it breaks through the technical limitations of isolated calculation of a single pipeline, achieves self-calibration of the resistance drop of multiple pipelines in the entire system, and significantly improves the real-time performance and accuracy of pulverized coal pipeline resistance calculation under complex peak-shaving conditions. Attached Figure Description

[0049] Figure 1 This is a schematic flowchart of a method for calculating the resistance of pulverized coal pipelines in thermal power plants, provided in one embodiment of this application.

[0050] Figure 2 This is a schematic diagram of the module of a measurement system provided in an embodiment of this application.

[0051] Figure 3 This is a schematic diagram of the modules of an electronic device provided in an embodiment of this application. Detailed Implementation

[0052] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them.

[0053] It should be noted that, in the embodiments of this application, "at least one" refers to one or more, and "more than one" refers to two or more. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in the specification of this application is for the purpose of describing particular embodiments only and is not intended to be limiting of this application.

[0054] It should be noted that in the embodiments of this application, the terms "first," "second," etc., are used only for descriptive purposes and should not be construed as indicating or implying relative importance, nor as indicating or implying order. Features specified as "first" or "second" may explicitly or implicitly include one or more of the stated features. In the description of the embodiments of this application, words such as "exemplary" or "for example" are used to indicate examples, illustrations, or explanations. Any embodiment or design scheme described as "exemplary" or "for example" in the embodiments of this application should not be construed as being more preferred or advantageous than other embodiments or design schemes. Specifically, the use of words such as "exemplary" or "for example" is intended to present the relevant concepts in a concrete manner.

[0055] Based on the embodiments described in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0056] As thermal power equipment develops towards larger capacity, higher parameters, and deeper peak shaving, the operational stability and economy of boiler pulverizing systems place higher demands on the safe and efficient operation of the entire plant. During boiler operation in thermal power plants, pulverized coal pipelines, as key transport channels connecting the coal mill and burners, directly affect the balance of air-coal distribution among burners due to their internal gas-solid two-phase flow resistance characteristics. Uneven air-coal distribution not only leads to deteriorated boiler combustion, localized overheating, or coking, but can also cause serious safety accidents such as pulverized coal accumulation, blockage, or even pipe rupture in the pipelines. Therefore, accurately acquiring and real-time monitoring the resistance status of pulverized coal pipelines is of great significance for optimizing boiler combustion control, achieving air-coal balance regulation, and ensuring the safety of the pulverizing system.

[0057] In related technologies, the acquisition of resistance in pulverized coal pipelines in thermal power plants mainly relies on empirical formulas estimated during the design phase, or on periodic offline testing using manually installed pressure measuring points under specific operating conditions. However, empirical formulas typically assume ideal single-phase flow or steady gas-solid flow inside the pipeline, failing to accurately reflect the nonlinear effects of fluctuations in pulverized coal concentration, changes in coal quality, and frequent adjustments in primary air temperature and volume on resistance during actual operation. Furthermore, traditional offline testing methods suffer from data lag and incomplete coverage of operating conditions. Additionally, pulverized coal pipelines are prone to internal wall wear and localized dust accumulation due to high-concentration dust erosion during long-term operation, leading to dynamic evolution of actual resistance characteristics. Existing technologies struggle to achieve real-time, high-precision continuous measurement of pulverized coal pipeline resistance under complex and variable peak-shaving conditions, thus failing to provide timely and effective resistance feedback data for intelligent combustion optimization in thermal power plants.

[0058] In view of this, the method, system, and equipment provided in this application for calculating the resistance of pulverized coal pipelines in thermal power plants overcome the data lag and accuracy deviation problems caused by traditional methods that rely solely on empirical formulas or offline single-phase flow tests by deeply integrating the gas-solid two-phase flow dynamics model, the pipe wall wear evolution model, and the system-level air network topology solution. By introducing the pulverized coal flow pattern definition results, the accurate characterization of the gas-solid two-phase suspension state inside the pipeline is achieved; combined with the wear evolution model constructed based on historical operating data and coal quality characteristics, the long-term evolution effect of pipe wall roughness on resistance is dynamically corrected; furthermore, the air network topology structure is constructed using the total air volume conservation constraint of the pulverizing system and the outlet pressure field data for joint collaborative solution, breaking the technical limitations of isolated calculation of a single pipeline, realizing self-calibration of the resistance drop of multiple pipelines in the whole system, and significantly improving the real-time performance and accuracy of pulverized coal pipeline resistance calculation under complex peak-shaving conditions.

[0059] This application constructs a high-precision resistance calculation system covering the entire chain from microscopic gas-solid phase change sedimentation to macroscopic wind network topology coordination by further refining mechanisms such as wind speed and flow pattern definition, mapping of wear metal erosion, correction of abrupt local spalling of wear-resistant linings, and adaptive updating of reverse residuals. Based on this, automated data integration is achieved by combining a distributed control system (DCS) and an online analysis terminal, resulting in functions for diagnosing air-coal distribution imbalance and providing early warning of coal accumulation and pipe blockage based on dynamic resistance deviation and rate of change. The entire solution not only provides timely and reliable resistance feedback benchmarks for optimized combustion control in thermal power plants, effectively avoiding safety hazards such as boiler coking, localized overheating, and pipe blockage and rupture caused by uneven air-coal distribution, but also possesses online self-iterative evolution capabilities for the model, significantly reducing system maintenance costs and demonstrating high engineering practical value and promising prospects for widespread application.

[0060] Figure 1 This is a schematic flowchart illustrating a method for calculating the resistance of pulverized coal pipelines in thermal power plants, provided in one embodiment of this application. Figure 1The method for calculating the resistance of pulverized coal pipelines in thermal power plants, as shown, includes at least the following steps: S100: Collect the structural parameters of each pulverized coal pipeline in the target pulverizing system, and obtain the operating status data and coal quality characteristic data of each pulverized coal pipeline under the current operating conditions; S200: Input the structural parameters and operating status data of each pulverized coal pipeline into a preset gas-solid two-phase flow dynamics model, and combine the pulverized coal flow pattern definition results derived from the operating status data to calculate the basic value of the gas-solid two-phase friction resistance and the basic value of the local resistance of each pulverized coal pipeline under the current suspension state; S300: Obtain the historical cumulative operating data of each pulverized coal pipeline, and combine the coal quality characteristic data to calculate the resistance of each pulverized coal pipeline using a pipe wall wear evolution model. S400: Using the current pipe wall roughness correction value and the coal powder concentration calculated from the operating status data, nonlinear coupling correction is performed on the friction resistance base value and local resistance base value of each coal powder pipeline to obtain the correction resistance coefficient of each coal powder pipeline under the current operating conditions; S500: Based on the correction resistance coefficient of each coal powder pipeline and the operating status data, the initial resistance drop of each coal powder pipeline is initially calculated; S600: Construct the air network topology of the target pulverizing system, and use the outlet pressure field data of each coal powder pipeline and the total air volume conservation constraint of the pulverizing system to jointly and collaboratively solve the initial resistance drop of each coal powder pipeline, and output the calibrated resistance calculation results of each coal powder pipeline.

[0061] S100: Collect the structural parameters of each pulverized coal pipeline in the target pulverizing system, and obtain the operating status data and coal quality characteristic data of each pulverized coal pipeline under the current working conditions.

[0062] In this embodiment of the application, the method for calculating the resistance of pulverized coal pipelines in thermal power plants includes, in step S100, collecting the structural parameters of each pulverized coal pipeline in the target pulverizing system, and obtaining the operating status data and coal quality characteristic data of each pulverized coal pipeline under the current operating conditions.

[0063] Specifically, the structural parameters include the pipe diameter of each pulverized coal pipeline, the length of each straight pipe section, the bending radius and bending angle of elbows, the dimensions of the transition section between the reduced and expanded diameters, the opening degree of the throttling valve, and the structural type; the operating status data is retrieved in real time through communication with the distributed control system (DCS), including the primary air volume, primary air temperature, real-time coal feed rate of the coal feeder, and pipeline inlet pressure of each pulverized coal pipeline; the coal quality characteristic data is obtained through an online coal analyzer or a periodic testing database, including pulverized coal moisture, ash content, volatile matter, Hardgrove Grindability Index (HGI), and average particle size of pulverized coal (…). ).

[0064] It is understandable that the gas-solid two-phase flow resistance within a pulverizing system depends not only on the inherent geometric constraints (structural parameters) of the pipeline, but also on the drastic influence of the medium's thermodynamic state and solid phase properties. By comprehensively collecting three-dimensional fundamental data encompassing geometry, operation, and properties, high-fidelity input parameters can be provided for subsequent gas-solid two-phase flow dynamics calculations and nonlinear evolution corrections, avoiding the source errors caused by simply treating pulverized coal as a homogeneous fluid or ignoring differences in coal quality in traditional calculations.

[0065] S200: Input the structural parameters and operating status data of each pulverized coal pipeline into the preset gas-solid two-phase flow dynamics model, and combine the pulverized coal flow pattern definition results derived from the operating status data to calculate the basic values ​​of the gas-solid two-phase friction resistance and the basic values ​​of the local resistance of each pulverized coal pipeline under the current suspension state.

[0066] In this embodiment of the application, the method for calculating the resistance of pulverized coal pipelines in thermal power plants includes step S200, which involves inputting the structural parameters and operating status data of each pulverized coal pipeline into a preset gas-solid two-phase flow dynamics model, and combining the pulverized coal flow pattern definition results derived from the operating status data to calculate the basic value of the gas-solid two-phase friction resistance and the basic value of the local resistance of each pulverized coal pipeline in the current suspension state.

[0067] Specifically, the density and kinematic viscosity of the gaseous medium are calculated based on the primary air volume and air temperature, and then the cross-sectional average wind speed and solid-gas mass ratio (solid-gas ratio) are derived. Combining the current average wind speed and solid-gas ratio at the cross-section, and utilizing the preset Froude number... The flow pattern of pulverized coal particles in the pipeline (such as uniform suspension flow, non-uniform suspension flow, or bottom-sliding aggregate) is determined using a particle settling terminal velocity model. When the flow pattern is determined to be non-uniform suspension flow, a gas-solid phase change settling correction factor is introduced, and the basic values ​​of pure air single-phase resistance (using the Darcy-Weisbach equation) are nonlinearly superimposed to obtain the basic values ​​of friction resistance of each pulverized coal pipeline under the current gas-solid suspension phase. With local resistance base value .

[0068] It is understandable that the gas-solid two-phase flow in pulverized coal pipelines is prone to phase change from "uniform suspension" to "non-uniform deposition" under low wind speeds or high concentrations. The phase change process causes abrupt changes in the gas-solid collision frequency and slip velocity, resulting in significant nonlinearity in the drag characteristics. By defining the flow pattern and incorporating the "phase change sedimentation correction factor" into the physical dynamics model, the drastic impact of flow pattern changes on drag can be accurately captured, significantly improving the computational accuracy of the physical foundation model.

[0069] S300: Obtain historical cumulative operating data for each pulverized coal pipeline, and calculate the current pipe wall roughness correction value for each pulverized coal pipeline by combining coal quality characteristic data and using a pipe wall wear evolution model.

[0070] In this embodiment of the application, the method for calculating the resistance of pulverized coal pipelines in thermal power plants includes, in step S300, obtaining the historical cumulative operating data of each pulverized coal pipeline, and combining the coal quality characteristic data to calculate the current pipe wall roughness correction value of each pulverized coal pipeline through a pipe wall wear evolution model.

[0071] Specifically, the historical cumulative operating time of each pulverized coal pipeline since the last major overhaul is extracted from the historical database. Compared with historical average scour wind speed By combining the ash content and hardness indicators from coal quality data, the cumulative metal erosion wear depth of the pipeline inner wall is calculated using the micro-cutting wear equation. This will further increase the wear depth. Mapped to the pipe wall micromorphology evolution function, the equivalent absolute roughness of the pipe wall under the current working conditions is calculated. and the initial roughness of the pipe By comparison, the current pipe wall roughness correction value is calculated. .

[0072] Understandably, during long-term operation, the walls of pulverized coal pipelines in thermal power plants are subjected to high-speed erosion by high-hardness pulverized coal particles. The inner wall gradually evolves from an initially smooth state to a rough morphology with wavy pits or longitudinal grooves. This morphological change continuously increases the near-wall frictional resistance between the pipe wall and the gas-solid-fluid mixture. By establishing a "wear evolution model" based on historical operating parameters and coal hardness, the dynamic tracking of the pipe wall roughness decay process is achieved, overcoming the limitation of traditional static resistance models in correcting long-term wear degradation.

[0073] S400: Using the current pipe wall roughness correction value and the coal powder concentration calculated from the operating status data, nonlinear coupling correction is performed on the basic value of friction resistance and the basic value of local resistance of each coal powder pipeline to obtain the correction resistance coefficient of each coal powder pipeline under the current operating conditions.

[0074] In this embodiment of the application, the method for calculating the resistance of pulverized coal pipelines in thermal power plants includes, in step S400, using the current pipe wall roughness correction value and the pulverized coal concentration calculated from the operating status data, performing nonlinear coupling correction on the basic value of the friction resistance and the basic value of the local resistance of each pulverized coal pipeline, to obtain the corrected resistance coefficient of each pulverized coal pipeline under the current operating conditions.

[0075] Specifically, the calculated real-time coal powder concentration Pipe wall roughness correction value The flow pattern definition results are input into the multivariate nonlinear response surface model. The first correction coefficient is calculated. (characterizing the amplification effect of the collision friction between the rough pipe wall and high-concentration coal powder particles on the friction coefficient along the pipe), and the second correction factor. (This characterizes the amplification effect of local resistance caused by secondary flow and particle aggregation at elbows and throttling valves due to high-concentration pulverized coal). Using the formula... as well as The corrected friction coefficients for each pulverized coal pipeline under the current operating conditions were obtained. With the corrected local drag coefficient .

[0076] It is understandable that there is a strong nonlinear coupling effect of "roughness-particle collision" between the rough pipe wall and the high-concentration pulverized coal fluid: the rougher the pipe wall, the greater the rebound angle and momentum loss of near-wall particles, resulting in an additional resistance increase far exceeding the sum of single factors. By using multivariate nonlinear response surfaces for coupling correction, the actual frictional resistance characteristics under the interaction of high-concentration gas-solid fluid and rough inner wall can be realistically reproduced.

[0077] S500: Based on the corrected resistance coefficient and operating status data of each pulverized coal pipeline, the initial resistance drop of each pulverized coal pipeline is initially calculated.

[0078] In this embodiment of the application, the method for calculating the resistance of pulverized coal pipelines in thermal power plants includes, in step S500, the initial resistance drop of each pulverized coal pipeline being initially calculated based on the corrected resistance coefficient and operating status data of each pulverized coal pipeline.

[0079] Specifically, the corrected friction coefficient under current operating conditions is considered. Corrected local drag coefficient Current cross-sectional average wind speed and the density of the mixed medium Using the extended fluid dynamics drag equation:

[0080]

[0081] Calculate the initial resistance reduction of each pulverized coal pipeline in the target pulverizing system under the assumption of independent operation. (in Representing the A coal powder pipeline, For the length of the pipe, (Pipe diameter).

[0082] Understandably, step S500 completes the mathematical deduction closed loop from physical parameters to the final resistance value under the "single pipe dimension". It integrates the calculation results of fluid dynamics, flow pattern change, wear attenuation and nonlinear coupling effect, and provides a high-precision single pipe initial iteration benchmark for subsequent topology collaborative solution of multiple pipes in the entire pulverizing air network.

[0083] S600: Construct the air network topology of the target pulverizing system, utilize the outlet pressure field data of each pulverized coal pipeline and the total air volume conservation constraint of the pulverizing system, jointly and collaboratively solve the initial resistance drop of each pulverized coal pipeline, and output the calibrated resistance calculation results of each pulverized coal pipeline.

[0084] In this embodiment of the application, the method for calculating the resistance of pulverized coal pipelines in thermal power plants includes, in step S600, constructing the wind network topology of the target pulverizing system, using the outlet pressure field data of each pulverized coal pipeline and the total air volume conservation constraint of the pulverizing system, jointly and collaboratively solving the initial resistance drop of each pulverized coal pipeline, and outputting the calibrated resistance calculation results of each pulverized coal pipeline.

[0085] Specifically, taking the pulverized coal system outlet mixing explosion-proof door / distributor as the starting node and the pulverized coal pipeline outlet burners as the ending nodes, multiple parallel pulverized coal pipelines are abstracted as air network branches, constructing an air network topology structure including an association matrix and a loop matrix. The real-time pressure field of the furnace at each burner outlet is used as the terminal pressure boundary condition to reduce the initial resistance of each pipeline. As the initial value for branch resistance, Kirchhoff's first law (total air volume conservation) is introduced. Based on Kirchhoff's second law (pressure difference balance in parallel loops), the Hardy-Cross iterative algorithm or the Newton-Raphson method is used to jointly solve the wind network equations, dynamically correcting the airflow distribution deviations in each branch, and finally outputting the accurate resistance calculation results of each pulverized coal pipeline after joint calibration. .

[0086] Understandably, in actual power plant operation, multiple pulverized coal pipelines do not exist in isolation, but rather share the same pulverizing system inlet and are affected by the reverse impact of the furnace outlet pressure field. Even the most precise single-pipe calculations cannot completely eliminate system-level pressure difference disturbances caused by cross-distribution of airflow. By constructing a "wind network topology" and introducing "total airflow conservation and network coordination constraints," a technological leap from "isolated single-pipe calculations" to "full network coordinated calculations" has been achieved, significantly improving the system-level robustness and absolute accuracy of resistance calculation results under multi-pipe coordinated operation conditions.

[0087] In this embodiment, the calculation of the basic values ​​of the gas-solid two-phase friction resistance and the basic values ​​of the local resistance of each pulverized coal pipeline under the current suspension state includes: acquiring the primary air volume, primary air temperature, and coal feed rate from the operating status data, and calculating the current cross-sectional average wind speed and solid-gas mass ratio in each pulverized coal pipeline. The motion pattern of pulverized coal particles within the pipeline is determined using the current cross-sectional average wind speed and the solid-gas mass ratio. When the motion pattern is a non-uniform suspension flow, a gas-solid phase change sedimentation correction factor is introduced based on the pulverized coal flow pattern definition result. The basic values ​​of the single-phase air resistance calculated based on the structural parameters are then nonlinearly superimposed to obtain the basic values ​​of the gas-solid two-phase friction resistance and the basic values ​​of the local resistance of each pulverized coal pipeline under the current suspension state.

[0088] Specifically, the gas density is calculated using the primary air temperature and the current pipeline pressure. Combined with primary air volume With pipe cross-sectional area The average wind speed at the current cross section is calculated. Meanwhile, based on the coal feed rate Gas mass flow rate Calculate the solid-to-gas mass ratio (solid-to-gas ratio) ).

[0089] Average wind speed at the current cross section Compared to solid-gas ratio Substitute into the Froude number calculation equation (in It is the acceleration due to gravity. (Equivalent inner diameter of the pipe), combined with the final settling velocity of pulverized coal particles. Determine the motion state of particles:

[0090] when At that time, the flow pattern was determined to be a uniform suspended flow;

[0091] when When the flow pattern is determined to be non-uniform suspension flow (partial settling and bottom slippage of particles occurs).

[0092] In non-uniform suspension flow, due to particle settling and aggregation, a gas-solid phase change sedimentation effect occurs. Therefore, a gas-solid phase change sedimentation correction factor is introduced. (in (These are fitting constants). The basic values ​​of single-phase air resistance are calculated using the Darcy-Weisbach equation. Based on this, by superimposing the solid phase additional drag term, we obtain the basic value of the gas-solid two-phase friction drag:

[0093]

[0094] Similarly, for elbows and valves, based on the local resistance coefficient... The basic value of local resistance is calculated by superimposing the solid phase additional coefficient. .

[0095] Understandably, in gas-solid two-phase flow transport, a decrease in wind speed or an increase in concentration can cause coal particles to transition from a fully suspended state to a non-uniform settling state (phase change), resulting in a non-linear increase in collisions between particles and the pipe wall, as well as in the viscous resistance between particles. By accurately determining the flow pattern through real-time calculation of wind speed and solid-gas ratio, and by precisely introducing a "gas-solid phase change settling correction factor" in the non-uniform suspension state, the limitations of traditional single-phase flow or fixed solid-gas ratio assumptions can be overcome, and the basic resistance of gas-solid two-phase flow under different flow phase states can be accurately reproduced.

[0096] In this embodiment, the friction loss and local resistance of each pulverized coal pipeline are nonlinearly coupled and corrected using the current pipe wall roughness correction value and the pulverized coal concentration calculated from the operating status data. This results in a corrected resistance coefficient for each pipeline under its current operating condition. The correction includes: calculating the real-time pulverized coal concentration in each pipeline using the solid-gas mass ratio; inputting the real-time pulverized coal concentration, the current pipe wall roughness correction value, and the motion flow pattern into the resistance coefficient correction model to calculate the first correction coefficient for friction loss due to pipe wall roughness and pulverized coal particle collision friction, and the second local resistance correction coefficient for high-concentration pulverized coal at bends and valves; and multiplying the first and second local resistance correction coefficients by the gas-solid two-phase friction loss and local resistance base values, respectively, to obtain the corrected resistance coefficient for each pulverized coal pipeline under its current operating condition.

[0097] Specifically, based on the solid-to-gas mass ratio The real-time pulverized coal volume concentration in the pipeline was calculated based on the relative slip velocity between the gas and solid phases. ;

[0098] Real-time coal powder concentration The current pipe wall roughness correction value calculated in step S300 And the current motion flow pattern is substituted into the three-dimensional response surface correction model:

[0099] First correction factor (Friction correction along the path):

[0100]

[0101] (in The empirical index characterizes the amplification effect of micro-pits near the rough pipe wall on the reflected momentum loss of high-concentration coal powder particles.

[0102] Second local resistance correction factor (Local resistance correction):

[0103] Based on the elbow curvature radius / valve throttling ratio and the flow pattern, the local agglomeration degree of high-concentration pulverized coal under centrifugal force is calculated using the following formula:

[0104]

[0105] (in For correction factor, (For bends and turns).

[0106] The first correction factor Compared with the basic value of friction resistance Multiplying the corresponding base coefficients yields the corrected friction coefficient for the current operating condition. The second local resistance correction factor With local resistance base value Multiplying the corresponding basic coefficients yields the corrected local drag coefficient. .

[0107] It is understandable that the increased micro-roughness caused by pipe wall wear is not an isolated effect, but rather a strong nonlinear coupling between the high concentration of pulverized coal particles and the roughness-particle collision. The greater the roughness, the more violent the disordered motion after particle collision and rebound, and the more flow energy is consumed. Simultaneously, high-concentration pulverized coal will cause secondary particle aggregation due to centrifugal force when passing through bends or valves, exacerbating local energy loss. The solution obtained through a multivariate nonlinear coupling correction model is... and This enables precise calibration of the resistance coefficient under the combined effects of long-cycle wear and high-concentration fluid.

[0108] In this embodiment, the wind network topology of the target pulverizing system is constructed. Using the pressure field data at the outlet of each pulverized coal pipeline and the conservation constraint of the total airflow of the pulverizing system, the initial resistance drop of each pulverized coal pipeline is jointly and collaboratively solved, outputting the final calibrated resistance calculation results for each pulverized coal pipeline. This includes: treating each pulverized coal pipeline as a branch of the wind network, constructing a wind network topology matrix including the inlet node of the pulverizing system and the outlet nodes of each pipeline; calculating the initial resistance drop of each pulverized coal pipeline branch based on the corrected resistance coefficient and the current average wind speed at the cross-section; using the real-time pressure difference at the outlet node of each pulverized coal pipeline as the boundary condition, and combining the conservation equations of the total airflow of the pulverizing system and the airflow of each branch, iteratively solving the wind network topology matrix; using the obtained airflow distribution deviation value to dynamically calibrate the initial resistance drop; and outputting the final calibrated resistance calculation results for each pulverized coal pipeline.

[0109] Specifically, the target powder-making system includes A series of parallel pulverized coal pipelines, with the distributor inlet as the node. Each pipe outlet (burner inlet) is a node. :

[0110] Constructing the topological matrix and initial calculations: Constructing The wind network correlation matrix is ​​based on the corrected resistance coefficient of each pipeline. With cross-sectional average wind speed The initial resistance drop of each branch was calculated. ;

[0111] Establish boundary conditions: Acquire pressure sensor data deployed at the inlet of each burner in the furnace. The real-time pressure difference between each exit node is obtained. ;

[0112] Collaborative Iterative Solution: Establishing the Wind Network Conservation Equations:

[0113]

[0114] Using the Hardy-Cross iterative algorithm, with the initial drag drop... The corresponding air volume is used as the initial value for iterative iteration to solve for the true calibrated air volume of each branch. and air volume distribution deviation value ;

[0115] Output calibration resistance: using the calibrated airflow Back-calculate the actual resistance drop of each branch pipe:

[0116]

[0117] Output This serves as the resistance calculation result after the final calibration of each pulverized coal pipeline.

[0118] Understandably, in a multi-pipe parallel pulverizing system, changes in the resistance of a single pipe can cause a redistribution of airflow and pressure across the entire system. Furthermore, the furnace interiors connected to each pipe outlet exhibit complex flow field pressure differences (the outlet boundaries are not independent). By constructing a "wind network topology matrix" and using "total airflow conservation" and "furnace outlet pressure difference" as collaborative constraints for joint iterative solutions, the problem of backflow and distribution deviations between pipes, which is neglected in isolated calculations of single pipes, is eliminated. This achieves extremely high-precision resistance calculation under a closed-loop network.

[0119] In this embodiment, historical cumulative operating data of each pulverized coal pipeline is obtained. Combined with coal quality characteristic data, the current pipe wall roughness correction value of each pulverized coal pipeline is calculated using a pipe wall wear evolution model. This includes: extracting the cumulative operating time and historical average wind speed of each pulverized coal pipeline from the historical cumulative operating data, and obtaining the pulverized coal ash content and hardness index from the coal quality characteristic data. Based on the cumulative operating time, historical average wind speed, pulverized coal ash content, and hardness index, the cumulative metal erosion wear of the inner wall of each pulverized coal pipeline is calculated. The cumulative metal erosion wear is mapped to the pipe wall microstructure evolution curve to calculate the current pipe wall roughness correction value that matches the current cumulative wear state of each pulverized coal pipeline.

[0120] Specifically, the cumulative operating time of each pulverized coal pipeline since the last overhaul is retrieved from the historical database. Compared with historical average scour wind speed Simultaneously retrieve the ash content mass fraction of pulverized coal from the coal quality analysis data. and Mohs hardness or quartz equivalent hardness index .

[0121] Using the gas-solid erosion wear theory formula, the cumulative erosion wear depth of the pipe inner wall metal is calculated. :

[0122]

[0123] (in The erosion resistance coefficient of the pipe material. The wind speed abrasion index is usually taken as... ).

[0124] A fitting evolution curve equation for "metal wear depth - pipe wall micro-roughness" is established in advance. The calculated cumulative erosion wear depth Substituting the values ​​into the fitted curve equation, the absolute roughness under the current cumulative wear state can be calculated. and compare it with the initial roughness of the pipe at the factory. By performing the difference calculation, the current pipe wall roughness correction value can be obtained. .

[0125] It is understandable that the wear of the pipeline inner wall by pulverized coal is a physical process influenced by wind speed, operating time, and coal hardness. Higher wind speeds and greater ash hardness result in more intense microscopic cutting forces on the pipe wall. By establishing a "wear evolution model" based on the principle of microscopic cutting, combining macroscopic historical operating indicators with microscopic coal hardness parameters, it is possible to quantify the morphological degradation of the inner surface of the pipe wall caused by long-term erosion with high precision. This provides a reliable roughness parameter benchmark for subsequent dynamic correction of the resistance coefficient.

[0126] In this embodiment, the pulverized coal concentration calculated from the current pipe wall roughness correction value and operating status data is used to perform nonlinear coupling correction on the baseline values ​​of friction resistance and local resistance of each pulverized coal pipeline, obtaining the corrected resistance coefficient of each pulverized coal pipeline under the current operating conditions. This includes: inputting the current pipe wall roughness correction value into the anti-wear lining spalling discrimination model to determine the local abrupt roughness of the pipe wall for each pulverized coal pipeline; when the local abrupt roughness exceeds a preset abrupt threshold, calculating the increment of local eddy current resistance of the pipe wall based on the pulverized coal concentration calculated from the operating status data, and then superimposing the increment of local eddy current resistance onto the nonlinear coupling correction process of the baseline values ​​of friction resistance and local resistance to obtain the corrected resistance coefficient of each pulverized coal pipeline under the current operating conditions.

[0127] Specifically, the calculated current pipe wall roughness correction value The cumulative erosion stress input is used to develop a spalling discrimination model for wear-resistant liners (such as hexagonal mesh ceramic or high-chromium cast iron liners). When the calculated local erosion depth of the liner reaches the critical thickness of the wear-resistant layer, the discrimination model outputs a local spalling signal for the liner and updates the roughness at that location to a locally abrupt roughness containing step-like faults. .

[0128] when Exceeding the preset mutation threshold At that time, it was determined that there was a local geometric discontinuity on the inner wall of the pipeline. Using a dimensionality-reduced surrogate model based on numerical fluid dynamics (CFD), and according to the current coal powder volume concentration... With cross-sectional wind speed The local flow separation and secondary eddy energy loss caused by the fluid passing through the stepped fault are calculated to obtain the increase in local eddy resistance of the pipe wall. :

[0129]

[0130] (in (This is the eddy current enhancement coefficient). The increment of this local eddy current drag... In the process of superimposing the friction and local resistance corrections obtained in step S400, the corrected resistance coefficients of each pulverized coal pipeline under the lining damage condition are recalculated and updated. and .

[0131] It is understandable that after long-term operation, the wear-resistant lining of pulverized coal pipelines in thermal power plants may experience localized spalling or pitting. This localized geometric change can trigger intense fluid disintegration and eddy currents within the pipeline, resulting in additional resistance far exceeding that of normal uniform wear. By accurately capturing this abrupt change state through the "wear-resistant lining spalling discrimination model" and calculating the "local eddy current resistance increment," the model can accurately characterize the dramatic increase in actual resistance of the pipeline under abnormal damage conditions, greatly enhancing its ability to detect sudden pipeline failures.

[0132] In this embodiment, the method further includes: calculating the resistance deviation between each pulverized coal pipeline and the resistance change rate of a single pulverized coal pipeline within a set time window based on the resistance measurement results after calibration of each pipeline. The resistance deviation is compared with a preset air-coal imbalance threshold; when the resistance deviation exceeds the preset air-coal imbalance threshold, the air-coal distribution imbalance state of the target pulverizing system is determined. Simultaneously, the resistance change rate is compared with a preset critical threshold for pulverized coal accumulation and blockage; when the resistance change rate exceeds the preset critical threshold for pulverized coal accumulation and blockage, the pulverized coal pipeline with abnormal resistance is located and a pulverized coal accumulation and blockage warning signal is output.

[0133] Specifically, obtain the calibrated resistance calculation results of each pulverized coal pipeline output in step S600. ( ):

[0134] Diagnosis of air-powder distribution imbalance: Calculate the average resistance of each pipe. And solve for the resistance deviation of each pipe relative to the average value. When there exists a certain Exceeding the preset wind-powder imbalance threshold When the powder-making system is in a state of imbalance in air-powder distribution, a guide command for damper balance adjustment is output.

[0135] Dust accumulation and pipe blockage early warning and positioning: Set sliding time window (For example Real-time calculation of the first Rate of change of resistance over time in a pipe within a sliding window .when Exceeding the preset critical threshold for powder accumulation and pipe blockage And when it shows a continuous upward trend, determine the first If coal powder deposits, coke, or shows signs of blockage inside a coal powder pipeline, the system will automatically and accurately locate the abnormal pipeline and trigger a high-brightness warning and alarm on the monitoring interface.

[0136] Understandably, accurate resistance calculations can not only be used for condition monitoring but also provide diagnostic basis for safe production. The resistance deviation between pipes directly reflects the uniformity of the burner's airflow distribution, while an abnormally rapid increase in the resistance of a single pipe (excessive resistance change rate) is a precursor to pipe blockage caused by pulverized coal due to low airflow velocity or localized pulverization. By calculating the "resistance deviation value" and "resistance change rate," we have extended our functions from simple data calculation to advanced functions such as "combustion optimization diagnosis" and "proactive early warning of major safety hazards."

[0137] In this embodiment, the method further includes: after outputting the calibrated resistance calculation results for each pulverized coal pipeline, obtaining the actual measured pressure drop at the outlet of each pulverized coal pipeline. The residual value between the calibrated resistance calculation results and the actual measured pressure drop is calculated. When the residual value exceeds a preset deviation threshold, the residual value is used to perform a reverse gradient update on the flow resistance coefficient in the preset gas-solid two-phase flow dynamics model and the wear rate parameter in the pipe wall wear evolution model.

[0138] Specifically, during system operation, high-precision differential pressure sensors at both ends of the pipeline are used to obtain the actual measured pressure drop at the outlet and inlet of each pulverized coal pipeline in real time. .

[0139] Calculate the calibrated resistance measurement results Compared with the actual measured pressure drop Error residual value between .

[0140] like Exceeding the preset deviation threshold Then, construct a loss function with the objective of minimizing the residual variance:

[0141]

[0142] in To include the basic flow resistance coefficient and wear rate parameters The parameter set. The loss function with respect to the parameters is obtained using stochastic gradient descent (SGD) or the Levenberg-Marquardt algorithm. The gradient is calculated, and the parameters are updated along the negative gradient direction:

[0143]

[0144] (in (This is the learning rate). The updated parameters automatically replace the corresponding constants in the original dynamic model and wear model for drag calculation in the next cycle.

[0145] Understandably, during long-term operation of a power plant, coal type drift, equipment aging, or sensor drift can all lead to cumulative deviations in the preset physical model and wear parameters. By introducing a "residual calculation and reverse gradient update mechanism," a data feedback closed loop is established. When discrepancies arise between the actual measured pressure difference and the model's calculation results, the system can adaptively correct the dynamic drag coefficient and wear rate parameters in reverse, giving the calculation model the ability to "learn online" and "evolve itself," ensuring the sustained high accuracy of the drag calculation method during long-term operation.

[0146] The complete workflow of the method for calculating the resistance of pulverized coal pipelines in thermal power plants provided in this application is described below with an exemplary embodiment.

[0147] In a certain In the actual operation of a coal pulverizing system in a thermal power plant boiler, the system is equipped with a coal mill and burners extending from the distributor to different layers of the boiler. A series of parallel pulverized coal pipelines (labeled sequentially as pipeline A, pipeline B, pipeline C, and pipeline D). The complete workflow of the method for calculating the resistance of pulverized coal pipelines in thermal power plants provided in this application embodiment is as follows:

[0148] First, perform data acquisition and basic parameter initialization.

[0149] The system retrieves the pipe geometry parameters (such as pipe diameter) of pipes A to D in the pulverizing system. (Length of each straight pipe section, radius of curvature of elbows, and opening of throttle valves). Simultaneously, it retrieves real-time operating status data under current conditions, including the primary air volume of each pipeline, through a communication interface with the field distributed control system (DCS). Primary air temperature Real-time coal feed rate of coal feeder and pipeline inlet pressure It also retrieves data from the online coal analyzer to obtain the current moisture and ash content of the pulverized coal. Quartz equivalent hardness index and average particle size of coal powder .

[0150] Secondly, perform basic resistance calculations and flow pattern definition for gas-solid two-phase flow.

[0151] The system is based on the primary air temperature With air volume Calculate the density of the gaseous medium Average wind speed of the pipe cross section (For example, the measured value is) ), and calculate the solid-gas mass ratio. Average wind speed of the cross section Compared to solid-gas ratio The flow pattern is determined by substituting the Froude number into the calculation model. Assuming that the wind speed at section C of the pipe is low, the flow pattern is determined to be "non-uniform suspended flow," and the system automatically introduces a gas-solid phase change settling correction factor. By nonlinearly superimposing the basic values ​​of single-phase air resistance obtained from the Darcy-Weisbach equation, the basic values ​​of gas-solid two-phase friction resistance of pipes A to D under the current suspended phase state are calculated. With local resistance base value .

[0152] Furthermore, calculations were performed to estimate long-cycle pipe wall wear and localized abrupt roughness changes.

[0153] The system retrieves the cumulative operating time of pipelines A through D since the last major overhaul from the historical database. Hourly and historical average wind speeds, combined with coal dust ash content and hardness The cumulative erosion wear depth of the inner wall metal of each pipe was calculated using a pipe wall wear evolution model. The wear depth By mapping the microstructure evolution curve of the pipe wall, the absolute roughness under the current cumulative wear state can be obtained. and roughness correction value During this process, the anti-wear lining spalling discrimination model detected that due to long-term erosion by high-concentration coal dust, the local lining of pipe B reached a critical value and spalled off, resulting in a step-like abrupt roughness. The system automatically invokes a CFD dimensionality reduction surrogate model to calculate the local flow separation and secondary eddy energy loss generated when the fluid passes through the spalling fault, and solves for the increase in local eddy resistance of the pipe wall. .

[0154] Subsequently, the multivariate nonlinear coupling correction and initial drag drop solution were performed.

[0155] The system is based on the solid-gas ratio Solving for real-time pulverized coal volume concentration The concentration of pulverized coal Pipe wall roughness correction value The flow pattern definition results, along with the input flow pattern definition, are substituted into the multivariate nonlinear response surface model to calculate the first correction coefficient. (Friction correction along the path) and second correction factor (Local correction for elbows / valve). For pipe B, the previously calculated local eddy current resistance increment of the pipe wall is further superimposed. The corrected friction coefficients for pipelines A through D under the current operating conditions are calculated and updated. With the corrected local drag coefficient Furthermore, this is combined with the cross-sectional average wind speed. Based on the density of the mixed medium, the initial resistance drop of each pipe under the assumption of independent operation of a single pipe was initially calculated. .

[0156] Next, the wind network topology is constructed and a system-level joint collaborative solution is performed.

[0157] The system is constructed with the distributor inlet as the source node and the outlets of pipes A through D as the terminal nodes. Branch ventilation network topology matrix. Data from pressure sensors deployed at the burner inlets in each corner of the furnace is retrieved to obtain the real-time pressure difference between each outlet node. As a boundary condition, the initial resistance decreases. The corresponding air volume is used as the initial value for iteration, and the total air volume conservation equation of the pulverizing system is introduced ( The Hardy-Cross algorithm is used to iteratively solve the loop pressure difference balance equation, eliminating airflow distribution deviations, and finally back-calculating the true and accurate resistance measurement results of each pipeline after calibration. .

[0158] Finally, the system performs wind-dust imbalance diagnosis, dust accumulation early warning, and online adaptive model updates.

[0159] Imbalance and Early Warning: The system calculates the resistance deviation between the resistance drop measured in pipelines A through D in real time. And in Rate of change of resistance within the sliding time window When the rate of change of resistance in pipe B is detected... It shows a continuous and sharp upward trend and exceeds the preset critical threshold for powder accumulation and pipe blockage. At that time, the system immediately identified pipe B as an abnormal object and triggered a "highlight warning signal for localized powder accumulation and blockage in pipe B" on the DCS human-machine interface;

[0160] Model adaptive update: The system simultaneously acquires the actual pressure drop in the pipeline measured by the field differential pressure transmitter. Calculate the residual value between the measured resistance result and the actual pressure difference. If the residual value If the deviation exceeds the preset threshold, the system automatically constructs a loss function with the goal of minimizing the residual variance, and uses the stochastic gradient descent method to perform reverse gradient updates on the flow resistance coefficient in the gas-solid two-phase flow model and the wear rate parameter in the wear evolution model, thus completing the online self-evolution and adaptive calibration of the resistance calculation model.

[0161] Through the complete workflow described above, the embodiments of this application realize a closed-loop chain from "basic parameter acquisition - flow pattern and wear physical modeling - multivariate nonlinear correction - whole-network topology collaborative solution - fault diagnosis and early warning and model adaptive evolution", which significantly improves the real-time performance, accuracy and safety of pulverized coal pipeline resistance calculation under complex peak-shaving conditions in thermal power plants.

[0162] Figure 2 This is a schematic diagram of the modules of a measurement system provided in an embodiment of this application. For example... Figure 2 The measurement system 10 shown includes at least the following components: a data acquisition module 11, a basic resistance calculation module 12, a wear correction module 13, a dynamic coupling correction module 14, an initial resistance estimation module 15, and a wind network collaborative solution module 16.

[0163] In this embodiment, the data acquisition module 11 is used to collect the structural parameters of each pulverized coal pipeline in the target pulverizing system, and to obtain the operating status data and coal quality characteristic data of each pulverized coal pipeline under the current operating conditions. Please refer to the following for details. Figure 1 The details and their corresponding descriptions are not repeated here.

[0164] In this embodiment, the basic resistance calculation module 12 is used to input the structural parameters and operating status data of each pulverized coal pipeline into a preset gas-solid two-phase flow dynamics model, and calculate the basic value of the gas-solid two-phase friction resistance and the basic value of the local resistance of each pulverized coal pipeline in the current suspension state. Please refer to the following for details. Figure 1 The details and their corresponding descriptions are not repeated here.

[0165] In this embodiment, the wear correction module 13 is used to acquire historical cumulative operating data of each pulverized coal pipeline, and calculate the current pipe wall roughness correction value of each pulverized coal pipeline by combining coal quality characteristic data and using a pipe wall wear evolution model. Please refer to the following for details. Figure 1 The details and their corresponding descriptions are not repeated here.

[0166] In this embodiment, the dynamic coupling correction module 14 is used to perform nonlinear coupling correction on the basic values ​​of friction resistance and local resistance of each pulverized coal pipeline using the current pipe wall roughness correction value and the pulverized coal concentration calculated from the operating status data, to obtain the corrected resistance coefficient of each pulverized coal pipeline under the current operating conditions. Please refer to the following for details. Figure 1 The details and their corresponding descriptions are not repeated here.

[0167] In this embodiment, the initial resistance calculation module 15 is used to initially calculate the initial resistance drop of each pulverized coal pipeline based on the corrected resistance coefficient and operating status data of each pipeline. Please refer to the following for details. Figure 1 The details and their corresponding descriptions are not repeated here.

[0168] In this embodiment, the wind network collaborative solution module 16 is used to construct the wind network topology of the target pulverizing system. Utilizing the outlet pressure field data of each pulverized coal pipeline and the total airflow conservation constraint of the pulverizing system, it performs a joint collaborative solution for the initial resistance drop of each pulverized coal pipeline, outputting the calibrated resistance calculation results for each pipeline. Please refer to the following for details. Figure 1 The details and their corresponding descriptions are not repeated here.

[0169] Figure 3 This is an electronic device 20 provided in one embodiment of this application. For example... Figure 3 As shown, the electronic device 20 includes at least the following components: a processor 21 and a memory 22.

[0170] In this embodiment, the memory 22 is used to store executable instructions of the processor 21, which, when configured to execute instructions, implement... Figure 1 The method shown in the figure.

[0171] In one embodiment of this application, the program operating in the electronic device 20 may be a program that controls a central processing unit (CPU) or similar device to achieve the functions of the above-described embodiments of the present invention (a program that enables the computer to function). The information processed by these devices is then temporarily stored in random access memory (RAM) during processing, and subsequently stored in various ROMs such as read-only memory (Flash ROM) and hard disk drives (HDDs), and read, corrected, and written by the CPU as needed.

[0172] It should be noted that a portion of the electronic device 20 described above can also be implemented using a computer. In this case, the program for implementing the control function can be recorded on a computer-readable recording medium, and the program recorded on the recording medium can be read into the computer and executed.

[0173] It should be noted that the term "computer" as used here refers to a computer built into electronic device 20, employing hardware including an operating system and peripheral devices. Furthermore, "computer-readable recording media" refers to removable media such as floppy disks, magneto-optical disks, ROMs, and CD-ROMs, as well as storage devices such as hard drives built into the computer.

[0174] Furthermore, a "computer-readable recording medium" can include: a medium that dynamically stores a program for a short period of time, such as a communication line used when transmitting a program via a network such as the Internet or a communication line such as a telephone line; or a medium that stores a program for a fixed period of time, such as volatile memory inside a computer that serves as a server or client in this case. In addition, the aforementioned program can be a program used to implement the above-mentioned functions, or it can be a program that can implement the above-mentioned functions by combining with programs already recorded in the computer.

[0175] It is understood that the method, system, and equipment for calculating the resistance of pulverized coal pipelines in thermal power plants provided in this application overcome the data lag and accuracy deviation problems caused by traditional methods that rely solely on empirical formulas or offline single-phase flow tests by deeply integrating the gas-solid two-phase flow dynamics model, the pipe wall wear evolution model, and the system-level air network topology solution. By introducing the pulverized coal flow pattern definition results, a precise characterization of the gas-solid two-phase suspension state inside the pipeline is achieved; combined with the wear evolution model constructed based on historical operating data and coal quality characteristics, the long-term evolutionary influence of pipe wall roughness on resistance is dynamically corrected; furthermore, by using the total air volume conservation constraint of the pulverizing system and the outlet pressure field data to construct the air network topology structure for joint collaborative solution, the technical limitations of isolated calculation of a single pipeline are broken, and self-calibration of the resistance drop of multiple pipelines in the whole system is achieved, significantly improving the real-time performance and accuracy of pulverized coal pipeline resistance calculation under complex peak-shaving conditions.

[0176] Those skilled in the art should recognize that the above embodiments are only used to illustrate this application and are not intended to limit this application. Any appropriate changes and variations made to the above embodiments within the essential spirit and scope of this application fall within the scope of protection claimed in this application.

Claims

1. A method for calculating the resistance of pulverized coal pipelines in thermal power plants, characterized in that, The method includes: Collect the structural parameters of each pulverized coal pipeline in the target pulverizing system, and obtain the operating status data and coal quality characteristic data of each pulverized coal pipeline under the current working conditions; The structural parameters and operating status data of each pulverized coal pipeline are input into a preset gas-solid two-phase flow dynamics model. Combined with the pulverized coal flow pattern definition results derived from the operating status data, the basic values ​​of the gas-solid two-phase friction resistance and the basic values ​​of the local resistance of each pulverized coal pipeline under the current suspension state are calculated. The historical cumulative operating data of each of the pulverized coal pipelines is obtained, and the current pipe wall roughness correction value of each of the pulverized coal pipelines is calculated by combining the coal quality characteristic data and the pipe wall wear evolution model. Using the current pipe wall roughness correction value and the coal powder concentration calculated from the operating status data, the friction resistance base value and local resistance base value of each coal powder pipeline are nonlinearly coupled and corrected to obtain the corrected resistance coefficient of each coal powder pipeline under the current operating conditions. Based on the corrected resistance coefficient and operating status data of each pulverized coal pipeline, the initial resistance drop of each pulverized coal pipeline is initially calculated. The air network topology of the target pulverizing system is constructed. Using the pressure field data of each pulverized coal pipeline outlet and the total air volume conservation constraint of the pulverizing system, the initial resistance drop of each pulverized coal pipeline is solved jointly and collaboratively, and the calibrated resistance calculation results of each pulverized coal pipeline are output.

2. The method for calculating the resistance of pulverized coal pipelines in thermal power plants according to claim 1, characterized in that, The calculations yield the baseline values ​​of the gas-solid two-phase friction resistance and the baseline values ​​of the local resistance for each of the pulverized coal pipelines under the current suspension state, including: Obtain the primary air volume, primary air temperature, and coal feed rate from the operating status data, and calculate the current cross-sectional average wind speed and solid-gas mass ratio in each of the pulverized coal pipelines. The motion pattern of pulverized coal particles in the pipeline is determined by the average wind speed and solid-gas mass ratio of the current cross section. When the motion pattern is a non-uniform suspended flow, a gas-solid phase change sedimentation correction factor is introduced through the pulverized coal flow pattern definition result. The single-phase air resistance base value calculated based on the structural parameters is nonlinearly superimposed to obtain the gas-solid two-phase friction resistance base value and local resistance base value of each pulverized coal pipeline in the current suspended state.

3. The method for calculating the resistance of pulverized coal pipelines in thermal power plants according to claim 2, characterized in that, The method involves using the current pipe wall roughness correction value and the coal powder concentration calculated from the operating status data to perform nonlinear coupling correction on the baseline values ​​of the friction resistance and local resistance of each coal powder pipeline, thereby obtaining the corrected resistance coefficient of each coal powder pipeline under the current operating conditions, including: The real-time coal powder concentration in each of the coal powder pipelines is calculated using the solid-gas mass ratio. The real-time coal powder concentration, the current pipe wall roughness correction value, and the motion flow pattern are input into the resistance coefficient correction model to calculate the first correction coefficient of pipe wall roughness and coal powder particle collision friction on the frictional resistance, and the second local resistance correction coefficient of high-concentration coal powder at elbows and valves. The first correction coefficient and the second local resistance correction coefficient are multiplied by the basic values ​​of the gas-solid two-phase friction resistance and local resistance, respectively, to obtain the corrected resistance coefficients for each of the pulverized coal pipelines under the current operating conditions.

4. The method for calculating the resistance of pulverized coal pipelines in thermal power plants according to claim 3, characterized in that, The construction of the air network topology of the target pulverizing system utilizes the outlet pressure field data of each pulverized coal pipeline and the total air volume conservation constraint of the pulverizing system to jointly and collaboratively solve the initial resistance drop of each pulverized coal pipeline, outputting the final calibrated resistance calculation results of each pulverized coal pipeline, including: Each of the pulverized coal pipelines is taken as a branch of the air network, and an air network topology matrix including the inlet node of the pulverizing system and the outlet nodes of each pipeline is constructed. Calculate the initial resistance drop of each of the pulverized coal pipeline branches based on the corrected resistance coefficient and the current average wind speed at the cross section. Using the real-time pressure difference at the outlet nodes of each pulverized coal pipeline as the boundary condition, and combining the conservation equations of the total air volume of the pulverizing system and the air volume of each branch, the topology matrix of the air network is iteratively solved. The initial resistance drop is dynamically calibrated using the obtained air volume distribution deviation value, and the final calibrated resistance calculation results of each pulverized coal pipeline are output.

5. The method for calculating the resistance of pulverized coal pipelines in thermal power plants according to claim 1, characterized in that, The process of acquiring historical cumulative operating data for each of the pulverized coal pipelines and, in conjunction with the coal quality characteristic data, calculating the current pipe wall roughness correction value for each of the pulverized coal pipelines using a pipe wall wear evolution model includes: Extract the cumulative operating time and historical average wind speed of each pulverized coal pipeline from the historical cumulative operating data, and obtain the ash content and hardness index of pulverized coal from the coal quality characteristic data; Based on the cumulative operating time, historical average wind speed, pulverized coal ash content and hardness index, calculate the cumulative metal erosion wear of the inner wall of each pulverized coal pipeline; The cumulative metal erosion wear is mapped to the pipe wall micromorphology evolution curve, and the current pipe wall roughness correction value that matches the current cumulative wear state of each pulverized coal pipeline is calculated.

6. The method for calculating the resistance of pulverized coal pipelines in thermal power plants according to claim 5, characterized in that, The method involves using the current pipe wall roughness correction value and the coal powder concentration calculated from the operating status data to perform nonlinear coupling correction on the baseline values ​​of the friction resistance and local resistance of each coal powder pipeline, thereby obtaining the corrected resistance coefficient of each coal powder pipeline under the current operating conditions, including: The current pipe wall roughness correction value is input into the anti-wear lining spalling discrimination model to determine the local abrupt roughness of the pipe wall of each of the pulverized coal pipelines; When the local abrupt roughness of the pipe wall exceeds the preset abrupt threshold, the coal powder concentration estimated by combining the operating status data is used to calculate the local eddy current resistance increment of the pipe wall. The local eddy current resistance increment of the pipe wall is then superimposed on the nonlinear coupling correction process of the friction resistance base value and the local resistance base value to obtain the corrected resistance coefficient of each coal powder pipeline under the current operating condition.

7. The method for calculating the resistance of pulverized coal pipelines in thermal power plants according to claim 1, characterized in that, The method further includes: Based on the resistance calculation results of each pulverized coal pipeline after calibration, calculate the resistance deviation value between each pulverized coal pipeline and the resistance change rate of a single pulverized coal pipeline within a set time window. The resistance deviation value is compared with a preset air-powder imbalance threshold. When the resistance deviation value exceeds the preset air-powder imbalance threshold, the air-powder distribution imbalance state of the target pulverizing system is determined. Simultaneously, the resistance change rate is compared with a preset critical threshold for dust accumulation and blockage. When the resistance change rate exceeds the preset critical threshold for dust accumulation and blockage, the coal pulverized pipe with abnormal resistance is located and a dust accumulation and blockage warning signal is output.

8. The method for calculating the resistance of pulverized coal pipelines in thermal power plants according to claim 1, characterized in that, The method further includes: After outputting the resistance calculation results of each pulverized coal pipeline after calibration, the actual measured pressure drop at the outlet of each pulverized coal pipeline is obtained; Calculate the residual value between the calibrated resistance measurement result and the actual measured pressure drop; When the residual value exceeds the preset deviation threshold, the residual value is used to perform reverse gradient updates on the flow resistance coefficient in the preset gas-solid two-phase flow dynamics model and the wear rate parameter in the pipe wall wear evolution model.

9. A system for calculating the resistance of pulverized coal pipelines in thermal power plants, characterized in that, The system is adapted to implement the method as described in any one of claims 1 to 8, the system comprising: The data acquisition module is used to collect the structural parameters of each coal powder pipeline in the target pulverizing system, and to obtain the operating status data and coal quality characteristic data of each coal powder pipeline under the current working conditions. The basic resistance calculation module is used to input the structural parameters and operating status data of each pulverized coal pipeline into a preset gas-solid two-phase flow dynamics model, and calculate the basic value of the gas-solid two-phase friction resistance and the basic value of the local resistance of each pulverized coal pipeline in the current suspension state. The wear correction module is used to acquire the historical cumulative operating data of each of the pulverized coal pipelines, and combine the coal quality characteristic data to calculate the current pipe wall roughness correction value of each of the pulverized coal pipelines through the pipe wall wear evolution model. The dynamic coupling correction module is used to perform nonlinear coupling correction on the basic values ​​of friction resistance and local resistance of each of the coal powder pipelines by using the current pipe wall roughness correction value and the coal powder concentration calculated by the operating status data, so as to obtain the correction resistance coefficient of each of the coal powder pipelines under the current operating conditions. The initial resistance calculation module is used to calculate the initial resistance drop of each pulverized coal pipeline based on the corrected resistance coefficient and operating status data of each pulverized coal pipeline. The wind network collaborative solution module is used to construct the wind network topology of the target pulverizing system. It uses the pressure field data of each pulverized coal pipeline outlet and the total air volume conservation constraint of the pulverizing system to jointly solve the initial resistance drop of each pulverized coal pipeline and output the calibrated resistance calculation results of each pulverized coal pipeline.

10. An electronic device, characterized in that, include: processor; as well as A memory having computer-readable instructions stored thereon for controlling the processor to perform the method as described in any one of claims 1 to 8.

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