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CN-121996941-A - Boiler pipeline stress monitoring system

CN121996941ACN 121996941 ACN121996941 ACN 121996941ACN-121996941-A

Abstract

The invention discloses a boiler pipeline stress monitoring system, in particular to the field of pipeline stress analysis, the system comprises a multi-physical-field acquisition module, an uncertainty quantization module, a transient numerical simulation module, an evaluation prediction module and a model self-adaptive updating module. The boiler pipeline stress monitoring system generates a structured first pipeline characteristic containing uncertainty indexes through an uncertainty quantification module, achieves uncertainty quantification of multi-physical-field data, fully considers strong time-varying coupling relation of the multi-physical-field data in a flexible peak regulation process through a transient numerical simulation module, improves the precision of a numerical calculation model, relieves the defect of insufficient numerical simulation accuracy in the prior art, reduces deviation of life prediction results through an evaluation prediction module, improves accuracy of unit peak regulation operation safety margin evaluation, and relieves the defect of inaccurate safety margin evaluation in the prior art.

Inventors

  • CAO TENG
  • ZHOU PENG
  • HAN SHUNSHUN

Assignees

  • 华电伊犁煤电有限公司

Dates

Publication Date
20260508
Application Date
20251219

Claims (8)

  1. 1. A boiler tube stress monitoring system, comprising: the multi-physical-field acquisition module is used for responding to a sensing device deployed at a preset position of the thick-wall part and acquiring first pipeline data in real time, wherein the first pipeline data comprises temperature, strain and pressure; an uncertainty quantization module for performing a preprocessing operation on the first pipeline data to generate a first pipeline feature including an uncertainty indicator; The transient numerical simulation module is used for carrying out transient numerical simulation by taking the first pipeline characteristic as a boundary condition based on a preset three-dimensional geometric model, and calculating and outputting a second pipeline characteristic representing time-varying characteristics; The evaluation prediction module is used for calculating interaction of fatigue damage and creep damage based on the second pipeline characteristics so as to acquire third pipeline characteristics comprising damage cost and safety margin; And the model self-adaptive updating module is used for comparing the first pipeline characteristics with the second pipeline characteristics and generating error indexes and dynamically adjusting the operation parameters of the transient numerical simulation module.
  2. 2. A boiler duct stress monitoring system as set forth in claim 1 wherein said multi-physical acquisition module, said thick wall component comprises a final superheater outlet header and a final reheater outlet header, said predetermined locations comprising an intersection line region of header pipe joints with the drum, a chamfer location at header openings, and a tee connection location in the duct system.
  3. 3. The system for monitoring the stress of a boiler pipe according to claim 1, wherein said uncertainty quantization module generates said first pipe characteristic comprising: calculating the statistical standard deviation of the first pipeline data as a first uncertainty component by adopting a Bessel formula within a preset time window; evaluating the standard uncertainty of the sensing device through normal distribution hypothesis according to the accuracy index of the sensing device, and taking the standard uncertainty as a second uncertainty component; And synthesizing the first uncertainty component and the second uncertainty component to generate an uncertainty interval.
  4. 4. The system for monitoring the stress of a boiler pipeline according to claim 1, wherein the transient numerical simulation module is configured to obtain the second pipeline characteristic, and the system specifically comprises: Reading a physical quantity value in the first pipeline characteristic and an uncertainty interval of the physical quantity value; Generating N groups of boundary condition samples in the uncertainty interval, wherein N is more than or equal to 1000; performing multiple parallel simulation on N groups of samples; Carrying out statistical analysis on the set of all simulation results, and taking 5% quantiles, median and 95% quantiles of the results of each time point so as to obtain the second pipeline characteristics expressed in a probability distribution form; the second pipe feature comprises at least a time series, a median and a quantile of equivalent stress, and a median and a quantile of damage variable.
  5. 5. The system for monitoring the stress of a boiler pipeline according to claim 4, wherein said transient numerical simulation module is configured to employ said damage variable in an isotropically damaged state Quantifying the microscopic defect density, specifically expressed as: Wherein, the Expressed as a tensor of stress, Expressed as the intrinsic modulus of elasticity in the high temperature environment within the insulating volume of the bale, Expressed as elastic strain tensors.
  6. 6. The system for monitoring the stress of a boiler pipeline according to claim 1, wherein the evaluation prediction module is configured to obtain the third pipeline characteristic, and specifically comprises: Extracting stress-time history and temperature-time history from preset monitoring points based on time-varying stress field, strain field and temperature field data contained in the second pipeline characteristics; respectively calculating fatigue damage caused by cyclic load and creep damage caused by combined action of steady-state load and high temperature in a target monitoring time period; by coupling the fatigue damage and the creep damage, a third pipe characteristic comprising the remaining life is calculated.
  7. 7. The system for monitoring the stress of a boiler pipe according to claim 6, wherein said evaluation prediction module calculates the interaction of fatigue damage and creep damage, and specifically comprises: Respectively calculating total fatigue damage caused by cyclic load in preset time And total creep damage caused by steady state load retention : The total fatigue damage The rain flow count is carried out on the stress-time history of the monitoring point to obtain Stress cycle of the first Cycle by cycle, fatigue damage is Wherein Indicating that this cycle has taken place once, Expressed as the number of cycles allowed for the corresponding material at the cyclic stress level, and total fatigue damage is the sum of all cycle damage, specifically expressed as: The total creep damage By dividing time into A steady state load holding section for the first For a time period of time of The creep rupture time of the material at the corresponding temperature and stress level in the time period is Creep damage generated in the time period is Total creep damage The sum of the damage for all time periods is specifically expressed as: The calculated total fatigue damage And total creep damage Comparing with an envelope determined by material experiments, the envelope is obtained by Is a transverse axis, In a coordinate system with a vertical axis, boundaries of the safety and failure regions are defined.
  8. 8. A boiler duct stress monitoring system as set forth in claim 6 wherein said assessment prediction module is based on an average temperature in said second duct feature under steady state operating conditions Equivalent to average stress The interaction of fatigue damage with creep damage provides a prediction of long-term creep life, specifically expressed as: Wherein, the Expressed as a constant of the material of the pipe, Represented as a predicted lifetime, which is indicated as a predicted lifetime, The thermal strength parameter, expressed as a pipe material, is determined by a polynomial equation fitted from the material high temperature creep test data: Wherein, the Are all fitting constants for the target monitoring material.

Description

Boiler pipeline stress monitoring system Technical Field The invention relates to the technical field of pipeline stress analysis, in particular to a boiler pipeline stress monitoring system. Background Along with the increasing of stress monitoring requirements under strong transient working conditions, the numerical solution precision of the transient multi-physical field coupling problem becomes a core bottleneck for limiting the accuracy of life prediction, the traditional technology generally carries out mechanical stress calculation and thermal stress estimation by measuring physical parameters of key nodes and relying on a simplified calculation model under steady-state working conditions, but actual measurement shows that the simulation is difficult to accurately capture the multi-physical field strength time-varying characteristic due to the lack of a coupling calculation model aiming at the transient temperature gradient and the dynamic alternating thermal stress in a thick-wall part, so that the calculation evaluation result of fatigue damage in a stress concentration area is seriously misaligned, and reliable calculation data support cannot be provided for safety risk early warning. In order to overcome the defects of the traditional technology, the prior art builds a three-dimensional geometric model through computer assistance and loads thermophysical attribute parameters, adopts a computational fluid dynamics and structural mechanics coupling solving algorithm, relies on a numerical simulation technology to simulate the internal transient temperature field and stress field distribution caused by fluid temperature change under the transient working condition, remarkably improves the calculation and analysis precision of the dangerous point stress-strain evolution rule from an algorithm level, and optimizes the suitability and reliability of the numerical simulation algorithm. However, in practical use, the method still has some defects, such as lack of measured data of multiple physical fields in a high-temperature environment, lack of effective verification data set support for convergence and precision of a coupling algorithm, difficulty in quantification of uncertainty of a numerical solution, and insufficient precision of a numerical calculation model for capturing time-varying coupling characteristics of multiple physical fields under a strong transient working condition, failure to fully consider a strong time-varying coupling relation of multiple physical fields in a flexible peak regulation process, insufficient accuracy of numerical simulation, deviation of life prediction results, and influence on evaluation accuracy of safety margin of unit peak regulation operation. Disclosure of Invention In order to overcome the above-mentioned drawbacks of the prior art, the present invention provides a boiler pipeline stress monitoring system, which solves the problems set forth in the above-mentioned background art through the following schemes. In order to achieve the above purpose, the present invention provides the following technical solutions: a boiler tube stress monitoring system, comprising: the multi-physical-field acquisition module is used for responding to a sensing device deployed at a preset position of the thick-wall part and acquiring first pipeline data in real time, wherein the first pipeline data comprises temperature, strain and pressure; an uncertainty quantization module for performing a preprocessing operation on the first pipeline data to generate a first pipeline feature including an uncertainty indicator; The transient numerical simulation module is used for carrying out transient numerical simulation by taking the first pipeline characteristic as a boundary condition based on a preset three-dimensional geometric model, and calculating and outputting a second pipeline characteristic representing time-varying characteristics; The evaluation prediction module is used for calculating interaction of fatigue damage and creep damage based on the second pipeline characteristics so as to acquire third pipeline characteristics comprising damage cost and safety margin; And the model self-adaptive updating module is used for comparing the first pipeline characteristics with the second pipeline characteristics and generating error indexes and dynamically adjusting the operation parameters of the transient numerical simulation module. Preferably, the multi-physical acquisition module comprises a final superheater outlet header and a final reheater outlet header, and the preset position comprises an intersecting line area of a header pipe joint and a cylinder body, a chamfering part at an opening of the header and a three-way connection part in a pipeline system. Preferably, the uncertainty quantization module generates the first pipeline feature, specifically including: calculating the statistical standard deviation of the first pipeline data as a first uncertainty component by ad