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CN-122019917-A - Modeling and online inversion method for inner wall erosion of Isa furnace

CN122019917ACN 122019917 ACN122019917 ACN 122019917ACN-122019917-A

Abstract

The invention discloses a modeling and on-line inversion method for erosion of an inner wall of an Isa furnace, which belongs to the field of Ai Sa furnace wall thickness calculation and comprises the steps of establishing a furnace wall temperature dynamic model, uniformly merging inner liner thickness change, parameter time varying and unmodeled disturbance into an equivalent unknown dynamic item, estimating the unknown dynamic item on line only by using a furnace wall temperature measured value based on a first-order low-pass filtering and algebraic reconstruction technology, and performing inverse solution to obtain equivalent thermal resistance and inner liner real-time thickness, and outputting a thickness curve conforming to an erosion physical trend through engineering constraint and smoothing treatment. The invention has the advantages of no need of temperature derivative signals, simple algorithm structure, small calculated amount and strong robustness, is suitable for real-time monitoring and early warning of high-temperature metallurgy sites, and provides reliable basis for safe production and maintenance decision.

Inventors

  • ZHANG FAXIANG
  • LU BINGJIANG
  • YANG CHUNXI

Assignees

  • 昆明理工大学

Dates

Publication Date
20260512
Application Date
20260113

Claims (9)

  1. 1. A modeling and on-line inversion method for the erosion of the inner wall of an Isa furnace is characterized in that the solving process firstly establishes an energy balance model of the outer wall temperature measuring node based on the outer wall temperature, the temperature of the inner side of the furnace, the ambient temperature, the equivalent heat capacity at the outer wall temperature measuring node, the equivalent convection heat exchange coefficient between the outer wall and the environment, the outer wall heat exchange area and the equivalent thermal resistance items of three layers of materials, and derives the energy balance model of the outer wall temperature measuring node after setting state variables, and obtains three layers of heat conduction equivalent thermal resistance items, heat transfer parameter items related to the thermal resistance and outer wall heat dissipation parameter items; Defining a nominal coefficient item and constructing a nominal model item so as to simplify an energy balance model of the derived outer wall temperature measurement node, and obtaining filtered outer wall temperature and the nominal model item by introducing first-order low-pass filtering calculation; inverse solution of equivalent unknown dynamic terms is carried out according to the filtered outer wall temperature and nominal model terms; According to the equivalent unknown dynamic term after inverse solution and the heat transfer parameter term relevant to the inverse solution thermal resistance of the equivalent unknown dynamic term; Reversely solving equivalent thermal resistance items of the three-layer material according to heat transfer parameter items related to the reversely solved thermal resistance; And (5) reversely solving the real-time thickness of the lining according to the equivalent thermal resistance term of the reversely solved three-layer material to finish calculation.
  2. 2. The method for modeling and on-line inversion of erosion of inner wall of Isa furnace according to claim 1, wherein the energy balance model of the temperature measuring node of furnace wall has the following expression: In the formula, For the temperature of the outer wall, Is the temperature of the hot surface inside the furnace, In order to be at the temperature of the environment, Is the equivalent convective heat transfer coefficient between the outer wall and the environment, Is the heat exchange area of the outer wall, Is equivalent heat capacity at the temperature measuring node of the outer wall, The time of day is indicated as such, The equivalent thermal resistance of the three layers of materials is expressed as: In the formula, For the coefficient of thermal conductivity of the first layer, For the thickness of the first layer, Is the thickness of the second layer and the third layer, The heat conductivity coefficients of the second layer and the third layer are respectively.
  3. 3. The method for modeling and on-line inversion of inner wall erosion of Isa furnace according to claim 2, wherein said expression for deriving the energy balance model of the outer wall temperature measurement node after setting the state variables comprises: Let state variables ; The expression for deriving the energy balance model of the outer wall temperature measuring node is as follows: In the formula, Is a heat transfer parameter related to thermal resistance; The heat dissipation parameter is the outer wall heat dissipation parameter; Is an equivalent unknown dynamic term.
  4. 4. The method for modeling and on-line inversion of erosion of inner wall of Isa furnace according to claim 3, wherein said heat transfer parameters related to thermal resistance are expressed as follows: The expression of the outer wall heat dissipation parameters is as follows: the expression of the equivalent unknown dynamic term is as follows: In the formula, For the nominal coefficient of the model, , To an initial thickness of The equivalent thermal resistance below.
  5. 5. The method for modeling and on-line inversion of erosion of inner wall of Isa furnace according to claim 4, wherein said nominal model term has the expression: The expression after simplifying the energy balance model of the derived outer wall temperature measurement node is as follows: 。
  6. 6. the method for modeling and on-line inversion of Isa furnace inner wall erosion according to claim 5, wherein the expression of the inverse solution equivalent unknown dynamic term is as follows: In the formula, Representing the state variable after the filtering, Representing the nominal model after the filtering, In order to filter the parameters of the filter, 。
  7. 7. The method for modeling and on-line inversion of erosion of inner wall of Isa furnace according to claim 6, wherein the expression of heat transfer parameter term related to inverse solution thermal resistance is as follows: 。
  8. 8. the method for modeling and on-line inversion of erosion of inner wall of Isa furnace according to claim 7, wherein the expression of equivalent thermal resistance term of the anti-solution three-layer material is as follows: 。
  9. 9. The method for modeling and on-line inversion of Isa furnace inner wall erosion according to claim 8, wherein the expression of the inverse solution liner real-time thickness is as follows: 。

Description

Modeling and online inversion method for inner wall erosion of Isa furnace Technical Field The invention relates to the field of Ai Sa furnace wall thickness calculation, in particular to an Isa furnace inner wall erosion-oriented modeling and on-line inversion method. Background The Isa furnace is a reaction vessel for high-temperature smelting, has the remarkable characteristics of high temperature resistance, corrosion resistance, complex structure and the like, and is widely applied to nonferrous smelting and complex smelting processes. The inner wall of the furnace lining can be continuously eroded under the actions of high temperature, slag scouring, chemical corrosion, thermal stress circulation and the like, the thickness reduction of the furnace lining can lead to the reduction of equivalent thermal resistance of the furnace body, the increase of the temperature of the outer wall and the reduction of structural safety margin, and the furnace shell can be overheated or even burnt out when serious. Therefore, the thickness and the change trend of the inner wall of the furnace lining can be continuously and reliably estimated, and the method is an important foundation for guaranteeing safe production, making a maintenance plan and optimizing working conditions. In actual production, the furnace reaction and the heat load show remarkable time variability and uncertainty, namely, the heat transfer process can be changed by the fluctuation of raw material components and granularity, the change of blowing/charging rhythm, the change of the molten pool state and slag layer thickness, the change of the outer wall heat exchange condition and the like, so that the model which only depends on fixed parameters is difficult to accurately describe the outer wall temperature dynamics for a long time. Meanwhile, the problems of noise, difference of installation positions, poor thermal contact and the like exist in the on-site temperature measurement signals, so that a solving method based on temperature derivatives is easy to interfere. There is therefore a need for an online solution that can stabilize the output thickness trend in the presence of model mismatch and disturbances. The existing erosion evaluation method mainly comprises an offline finite element analysis, an empirical formula calculation and a regression/identification method based on historical data. The offline finite element analysis has large calculation amount and difficult real-time updating, the empirical formula depends on specific working conditions and empirical constants, the application range is limited, the traditional regression or parameter identification is easy to drift under strong noise and time-varying disturbance, and frequent parameter adjustment is often needed to compromise between convergence speed and stability. In summary, a modeling and solving method with low calculation amount, on-line operation, compensation of model uncertainty and output of thickness curves conforming to erosion physical trend is needed. Disclosure of Invention In order to solve the technical problems, the invention provides a modeling and online inversion method for erosion of the inner wall of an Isa furnace. In order to realize the technology, the specific modes are as follows: an energy balance model of an outer wall temperature measurement node is established based on a heat conduction principle, and the expression is as follows: In the formula, For the temperature of the outer wall,Is the temperature of the hot surface inside the furnace,In order to be at the temperature of the environment,Is the equivalent heat capacity at the temperature measuring node of the outer wall and is used for representing the thermal inertia of the temperature of the outer wall,Is the equivalent convective heat transfer coefficient between the outer wall and the environment,Is the heat exchange area of the outer wall,The equivalent thermal resistance of the three layers of materials can be written as: In the formula, Is the thermal conductivity of the first layer (liner layer),For the first layer (liner layer) thickness,Is the thickness of the second layer and the third layer,The heat conductivity coefficients of the second layer and the third layer are respectively; Order state variables for facilitating subsequent solution The energy balance model of the outer wall temperature measuring node is derived and then is arranged as follows: Wherein, the Is a heat transfer parameter related to thermal resistance; The heat dissipation parameter is the outer wall heat dissipation parameter; Is an equivalent unknown dynamic term; further, the heat transfer parameter is related to the heat resistance The expression of (2) is as follows: further, the outer wall heat dissipation parameter The expression of (2) is as follows: Order the WhereinTo an initial thickness ofThe equivalent unknown dynamic term can be associated with the equivalent thermal resistance: Constructing a