CN-122015070-A - Hierarchical differential soot blowing control method and system for boiler

CN122015070ACN 122015070 ACN122015070 ACN 122015070ACN-122015070-A

Abstract

The invention relates to a hierarchical differential soot blowing control method and system for a boiler, which comprises the steps of obtaining soot deposition rate grid coordinate distribution of a hearth wall, screening by a first threshold value to obtain effective statistical data, screening by a second threshold value to determine dangerous deposition points, mapping the effective statistical data and the dangerous deposition points to corresponding soot blowing working areas according to space coordinates, respectively calculating dangerous deposition proportion of each soot blowing working area, judging whether the corresponding soot blowing working areas need to execute soot blowing, calculating average nearest neighbor distance of the dangerous deposition points in the soot blowing working areas needing to execute soot blowing, determining soot blowing grades, correcting the corresponding soot blowing grades according to operation parameters of each soot blowing working area, controlling each corresponding soot blower to execute differential soot blowing according to the corrected soot blowing grades, and updating each threshold value and the soot blowing grade according to soot blowing execution results to realize closed loop optimization. The boiler soot blowing control device realizes the fine control of boiler soot blowing and improves the operation safety and economy of the boiler.

Inventors

LIU XUEJIAO
Lai Hengkang
ZHOU GUANWEN
CHEN XI
LI YUANLU
LIU LI
ZHONG WENQI

Assignees

东南大学

Dates

Publication Date: 20260512
Application Date: 20260403

Claims (10)

1. The differential soot blowing control method for the boiler is characterized by comprising the following steps of: Acquiring grid coordinate distribution of ash deposition rate of a hearth wall surface, extracting an ash deposition rate value R corresponding to each grid point in a unified coordinate space, determining data meeting R not less than T 1 as effective statistical data, wherein T 1 is a set first threshold value used for representing an effective starting value of ash deposition, determining grid points meeting R not less than T 2 as dangerous deposition points, and T 2 is a second threshold value determined based on the distribution characteristics of the effective statistical data; Dividing the wall surface of the hearth into a plurality of soot blowing working areas according to the action coverage range of the soot blower, and mapping the effective statistical data and dangerous deposition points to the corresponding soot blowing working areas according to space coordinates; respectively calculating the ratio of the number of dangerous deposition points to the number of effective statistical data in each soot blowing working area to obtain the dangerous deposition proportion P of each soot blowing working area, comparing the P with a preset soot blowing threshold value, and judging whether the corresponding soot blowing working area needs to execute soot blowing or not; calculating an average nearest neighbor distance I of dangerous deposition points in a soot blowing working area where soot blowing is required to be performed, comparing the I with a plurality of preset grading thresholds, and determining soot blowing grades; correcting the corresponding soot blowing grade according to the operation parameters of each soot blowing working area; controlling each corresponding soot blower to execute differential soot blowing according to the corrected soot blowing grade; Continuously collecting an ash deposition rate value R and an operation parameter after the soot blowing is executed, and updating the T 1 、T 2 , the soot blowing threshold value, the grading threshold value and the soot blowing grade according to the soot blowing execution result and the working condition change; the calculating of the average nearest neighbor distance I comprises the following steps: Where N h is the total number of dangerous deposit points in the current soot blowing working area, and d i is the distance between the ith dangerous deposit point and its nearest dangerous deposit point.
2. The method according to claim 1, wherein the second threshold T 2 is determined by taking the effective statistics of all soot blowing operation areas as samples, or the second threshold T 2 of the respective area is determined by taking the effective statistics corresponding to each soot blowing operation area as samples.
3. The method according to claim 1, wherein the ash deposition rate grid coordinate distribution of the furnace wall surface is a CFD simulation result, an experimental test result or a final result of fusion correction of the CFD simulation and the experimental test result; the CFD simulation result is obtained by constructing a boiler CFD model, coupling a wall ash deposition model and calculating; And the experimental test result is obtained through on-site actual measurement, and the original data related to the deposition of the wall surface of the hearth is mapped into grid distribution after data processing.
4. The method of claim 3, wherein the on-site measurement comprises measuring a deposition state of a wall surface of the furnace to obtain a temperature field, a thermal field, image information and deposition thickness information of the wall surface of the furnace, and converting the obtained information into ash deposition rate values on a grid of the corresponding wall surface by image recognition, machine learning or artificial intelligence inversion.
5. The method of claim 1, wherein the step-wise differential soot blowing comprises increasing or decreasing soot blowing parameters of the respective soot blowing operating areas based on a reference soot blowing parameter preset by the soot blower, the soot blowing parameters comprising a number of soot blowing times, a single soot blowing duration, a soot blowing medium pressure, a soot blowing medium flow, a soot blowing inspection cycle.
6. The method of claim 1, wherein the operating parameters include physical parameters affecting slagging including CO concentration, wall temperature differential, smoke temperature adjacent to a soot blowing operating area.
7. The method of claim 1, wherein the operating condition changes include one or more of coal type, load, fuel charge location, and air distribution.
8. The method of claim 1, wherein the initial set of the first threshold T 1 , the sootblowing threshold, the classification threshold is set based on historical operational data of the boiler relating to soot deposition.
9. The method of claim 1, wherein the distribution characteristics of the effective statistics include high-scoring characteristics, frequency decay trends.
10. A hierarchical differentiated soot blowing control system for a boiler, applied to the method of any one of claims 1 to 9, said system comprising: The system comprises an acquisition and screening module, a data acquisition and screening module, a dangerous deposition point acquisition and screening module, a calculation module and a calculation module, wherein the acquisition and screening module is used for acquiring the grid coordinate distribution of the ash deposition rate of the wall surface of a hearth, extracting an ash deposition rate value R corresponding to each grid point in a unified coordinate space, determining data meeting R not less than T 1 as effective statistical data, T 1 as a set first threshold value used for representing the effective starting value of ash deposition, determining grid points meeting R not less than T 2 as dangerous deposition points, and T 2 as a second threshold value determined based on the distribution characteristics of the effective statistical data; The coordinate mapping module is used for dividing the hearth wall surface into a plurality of soot blowing working areas according to the action coverage range of the soot blower, and mapping the effective statistical data and dangerous deposition points to the corresponding soot blowing working areas according to space coordinates; The execution judging module is used for respectively calculating the ratio of the number of dangerous deposition points in each soot blowing working area to the number of effective statistical data to obtain the dangerous deposition proportion P of each soot blowing working area, comparing the P with a preset soot blowing threshold value and judging whether the corresponding soot blowing working area needs to execute soot blowing or not; The classification module is used for calculating the average nearest neighbor distance I of dangerous deposition points in a soot blowing working area where soot blowing is required to be performed, comparing the I with a plurality of preset classification thresholds and determining soot blowing grades; the correction module corrects the corresponding soot blowing grade according to the operation parameters of each soot blowing working area; The execution module is used for controlling each corresponding soot blower to execute differential soot blowing according to the corrected soot blowing grade; The updating module is used for continuously collecting the ash deposition rate value R and the operation parameters after the soot blowing is carried out, and updating the T 1 、T 2 , the soot blowing threshold value, the grading threshold value and the soot blowing grade according to the soot blowing execution result and the working condition change; the calculating of the average nearest neighbor distance I comprises the following steps: Where N h is the total number of dangerous deposit points in the current soot blowing working area, and d i is the distance between the ith dangerous deposit point and its nearest dangerous deposit point.

Description

Hierarchical differential soot blowing control method and system for boiler Technical Field The invention relates to the technical field of boiler soot blowing control, in particular to a method and a system for controlling boiler grading differentiation soot blowing. Background In the operation process of the coal-fired boiler of the power station, ash particles are deposited on the wall surface of the hearth to form accumulated ash and slag, so that the heat exchange of a heating surface is deteriorated, the wall temperature is increased, the efficiency of the boiler is reduced, and the safety risk is brought. In order to inhibit boiler slagging, a power station boiler adopts a hearth soot blower fixed on the wall surface of a hearth to perform soot blowing operation so as to clean the slagging. In the actual operation process, the utility boiler always performs regular and periodic full-hearth soot blowing, and often works according to the operation experience of staff, the soot blowing is difficult to adjust according to the complex uneven distribution of ash deposition slagging in the hearth, the problems that the local slagging of the hearth is seriously not treated in time and the low risk area is excessively soot blowing easily occur, and the steam consumption is increased and the abrasion of the metal pipe wall of the heating surface is aggravated. Therefore, the boiler slagging condition is necessarily evaluated by reasonable and accurate technical indexes, and meanwhile, the reasonable partition is carried out on the wall surface of the hearth to distinguish soot blowing, so that the method has important significance for safe and stable operation of the boiler. In the prior art, a patent CN106352320A divides a hearth into three sections of a main combustion area, a burnout area and a heat exchange area according to combustion properties, and water wall heat efficiency coefficients of different sections of the hearth are used as slagging monitoring indexes to guide soot blowing. The patent CN120145923A trains the neural network by taking the wall ash deposition rate as a technical index to predict the slagging of the hearth so as to provide a foundation for accurate soot blowing. The methods focus on the detection and prediction methods of boiler slagging, and how to use technical indexes to determine whether to perform soot blowing and how to perform graded differential soot blowing do not currently have a clear strategy and control method, and the soot blowing operation in actual operation still has difficulties. Disclosure of Invention Aiming at the defects of the prior art, the invention provides a hierarchical differential soot blowing control method and system for a boiler, which solve the problems of high energy consumption and heating surface abrasion caused by ineffective soot blowing and excessive soot blowing in the lack of pertinence of soot blowing control for the boiler in the prior art. The technical scheme adopted by the invention is as follows: The invention provides a hierarchical differential soot blowing control method for a boiler, which comprises the following steps: Acquiring grid coordinate distribution of ash deposition rate of a hearth wall surface, extracting an ash deposition rate value R corresponding to each grid point in a unified coordinate space, determining data meeting R not less than T 1 as effective statistical data, wherein T 1 is a set first threshold value used for representing an effective starting value of ash deposition, determining grid points meeting R not less than T 2 as dangerous deposition points, and T 2 is a second threshold value determined based on the distribution characteristics of the effective statistical data; Dividing the wall surface of the hearth into a plurality of soot blowing working areas according to the action coverage range of the soot blower, and mapping the effective statistical data and dangerous deposition points to the corresponding soot blowing working areas according to space coordinates; respectively calculating the ratio of the number of dangerous deposition points to the number of effective statistical data in each soot blowing working area to obtain the dangerous deposition proportion P of each soot blowing working area, comparing the P with a preset soot blowing threshold value, and judging whether the corresponding soot blowing working area needs to execute soot blowing or not; the method comprises the steps of comparing an average nearest neighbor distance I of dangerous deposition points in a soot blowing working area where soot blowing is required to be performed with a plurality of preset grading thresholds to determine soot blowing grades; correcting the corresponding soot blowing grade according to the operation parameters of each soot blowing working area; controlling each corresponding soot blower to execute differential soot blowing according to the corrected soot blowing grade; Continuously collecting an ash