Precise control method for transverse temperature of furnace rollers in the entrance area of ​​heating section of continuous annealing furnace

Abstract

The invention discloses a method for accurately controlling the transverse temperature of furnace rollers in an entrance area of ​​a heating section of a continuous annealing furnace, which is characterized in that the method comprises the following steps: establishing a temperature model, tracking and detecting data of the furnace roller temperature at the entrance of the heating section of the annealing furnace, the temperature in the furnace and the temperature of the strip, and using data simulation to establish temperature models of the furnace roller temperature at the entrance of the heating section, the temperature in the furnace and the temperature of the strip; establishing an automatic control system, measuring the strip temperature, the temperature in the furnace and the furnace roller temperature respectively through measuring elements, inputting the measured values ​​of corresponding temperature signals into the automatic control system, and comparing them with the set values ​​of the temperature control model, and inputting the obtained deviation values ​​into a controller, and the controller controls the hot crown fan in the furnace through an actuator, adjusts the air volume, and accurately controls the temperature of the area near the furnace roller, thereby realizing accurate control of the transverse temperature of the furnace roller, preventing the strip from deviating, and ensuring the stable operation of the strip in the annealing furnace.

Description

Technical Field

[0001] The invention belongs to the technical field of continuous annealing, and in particular relates to a method for accurately controlling the transverse temperature of a furnace roller in an inlet area of ​​a heating section of a continuous annealing furnace. Background Art

[0002] When the strip enters the entrance of the heating section of the annealing furnace, there is a large temperature difference between the cold strip and the furnace area. The heat exchange between the strip and the furnace roller in contact causes the temperature of the middle part of the furnace roller to drop, resulting in a large temperature difference in the lateral temperature of the furnace roller. Excessive lateral temperature difference of the furnace roller will cause different degrees of thermal convexity changes in the edge and center of the furnace roller, resulting in the failure of the annealing furnace roller convexity design and control effect, causing the strip to deviate in the furnace. Therefore, the precise control of the lateral temperature of the furnace roller in the entrance area of ​​the heating section of the annealing furnace has become a difficult problem for the stable operation of the strip. Summary of the invention

[0003] The object of the present invention is to provide a method for accurately controlling the transverse temperature of furnace rollers in an inlet area of ​​a heating section of a continuous annealing furnace.

[0004] The technical solution adopted by the present invention to solve the technical problem is: a method for accurately controlling the transverse temperature of a furnace roller in the entrance area of ​​a heating section of a continuous annealing furnace, characterized in that it comprises the following steps:

[0005] 1) Temperature collection: a high temperature radiometer is set at the entrance of the heating section of the annealing furnace to measure the temperature inside the furnace as T f , Strip temperature T s The protective gas in the furnace enters the furnace from the bottom of the furnace, is stirred by the movement of the strip, and heat is transferred between the strip and the radiation tube. The temperature at the end of the furnace roller is T e =1 / 2(T f +T s ), the middle of the furnace roller is in direct contact with the strip steel to generate heat conduction, and heat radiation occurs with the ambient temperature in the furnace. The temperature of the middle of the furnace roller is T c =f(T f , T s );

[0006] 2) Establish a temperature model by setting the temperature of the annealing furnace heating section entrance to T f , Strip temperature T s , furnace roller end temperature T e , furnace roller middle temperature T c Track and detect the data, and use data simulation to establish the temperature model of the heating section entrance furnace roller temperature, furnace temperature, and strip temperature;

[0007] 3) Determine the transverse temperature difference between the end and the middle of the furnace roller under the condition of positive convexity of the furnace roller. Through thermodynamic calculation, ensure that the temperature difference between the end and the middle of the furnace roller convexity is △T=T under the condition of ensuring that the strip does not deviate. e -Tc ≤120℃, ensuring stable operation of the strip;

[0008] 4) Establish an automatic control system, measure the strip temperature, furnace temperature and furnace roller temperature respectively through measuring elements, input the measured values ​​of the corresponding temperature signals into the automatic control system, and compare them with the set values ​​of the temperature control model, and input the obtained deviation values ​​into the controller. The controller controls the thermal crown fan in the furnace through the actuator, adjusts the air volume, and accurately controls the temperature of the area near the furnace roller, thereby realizing accurate control of the transverse temperature of the furnace roller;

[0009] 5) Accurate transverse temperature control of furnace rollers, transverse temperature difference of furnace rollers △T=T e -T c When △T>120℃, the measuring element feeds back the temperature signal to the automatic control system, and the actuator adjusts the fan air volume until △T=120℃, then the automatic control system stops adjusting to keep the parameters stable; when △T≤120℃, the automatic control system operates normally to keep the strip running stably.

[0010] The present invention has the following beneficial effects: a temperature control model is fitted by analyzing the relationship between the strip temperature, the temperature in the furnace and the furnace roller temperature and the strip operation; an automatic control system is established, the strip temperature is detected by a radiation pyrometer, the furnace temperature is detected by a thermocouple, and a fitting formula for the transverse temperature difference of the furnace roller is obtained, and the measured value of the corresponding temperature signal is input into the automatic control system, and compared with the set value of the temperature control model, and the obtained deviation value is input into the controller, and the controller controls the thermal crown fan in the furnace through the actuator to adjust the air volume, and the temperature of the area near the furnace roller is accurately controlled in combination with the actual operating parameters of the annealing furnace, so as to achieve the target control effect of the transverse temperature deviation of the furnace roller, ensure the actual roller crown under the thermal working state of the annealing furnace, and prevent the strip from running off. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 It is a schematic diagram of the structure of the automatic control system of the present invention.

[0012] Figure 2 This is a flow chart of precise control of the transverse temperature of the furnace rollers of the present invention.

[0013] In the figure: 1-sensor; 2-controller; 3-actuator; 4-fan control. DETAILED DESCRIPTION

[0014] The present invention will now be described in further detail with reference to the accompanying drawings.

[0015] like Figure 1-2The present invention fits the temperature control model by analyzing the relationship between the strip temperature, the furnace temperature and the furnace roller temperature and the strip operation; establishes an automatic control system, measures the strip temperature, the furnace temperature and the furnace roller temperature through measuring elements, specifically, a radiation pyrometer detects the strip temperature, a thermocouple detects the furnace temperature, and a furnace roller transverse temperature difference fitting formula is used, the measured value of the corresponding temperature signal is input into the automatic control system, and compared with the set value of the temperature control model, and the obtained deviation value is input into the controller 2, and the controller 2 controls the thermal crown fan in the furnace through the actuator 3 to adjust the air volume n f , accurately control the temperature of the area near the furnace roller, thereby achieving accurate control of the lateral temperature of the furnace roller, ensuring the actual roller crown under the thermal state of the annealing furnace, and preventing the strip from running off.

[0016] A method for accurately controlling the transverse temperature of a furnace roller in an entrance area of ​​a heating section of a continuous annealing furnace comprises the following steps:

[0017] 1) Temperature collection: a high temperature radiometer is set at the entrance of the heating section of the annealing furnace to measure the temperature inside the furnace as T f , Strip temperature T s The protective gas in the furnace enters the furnace from the bottom of the furnace, is stirred by the movement of the strip, and heat is transferred between the strip and the radiation tube. The temperature at the end of the furnace roller is T e =1 / 2(T f +T s ), the middle of the furnace roller is in direct contact with the strip steel to generate heat conduction, and heat radiation occurs with the ambient temperature in the furnace. The temperature of the middle of the furnace roller is T c =f(T f , T s );

[0018] 2) Establish a temperature model by setting the temperature of the annealing furnace heating section entrance to T f , Strip temperature T s , furnace roller end temperature T e , furnace roller middle temperature T c Track and detect the data, and use data simulation to establish the temperature model of the heating section entrance furnace roller temperature, furnace temperature, and strip temperature;

[0019] 3) Determine the transverse temperature difference between the end and the middle of the furnace roller under the condition of positive convexity of the furnace roller. Through thermodynamic calculation, ensure that the temperature difference between the end and the middle of the furnace roller convexity is △T=T under the condition of ensuring that the strip does not deviate. e -T c ≤120℃, ensuring stable operation of the strip;

[0020] 4) Establish an automatic control system, measure the strip temperature, furnace temperature and furnace roller temperature respectively through measuring elements, input the measured values ​​of the corresponding temperature signals into the automatic control system, and compare them with the set values ​​of the temperature control model, and input the obtained deviation values ​​into the controller 2. The controller 2 controls the thermal crown fan in the furnace through the actuator 3, adjusts the air volume, and accurately controls the temperature of the area near the furnace roller, thereby realizing accurate control of the lateral temperature of the furnace roller;

[0021] 5) Accurate transverse temperature control of furnace rollers, transverse temperature difference of furnace rollers △T=T e -T c When △T>120℃, the measuring element feeds back the temperature signal to the automatic control system, and the actuator 3 adjusts the fan air volume until △T=120℃, and the automatic control system stops adjusting to keep the parameters stable; when △T≤120℃, the automatic control system operates normally to keep the strip running stably.

[0022] The present invention establishes a temperature control model, clarifies the lateral temperature difference standard of the furnace roller, and realizes precise control of the lateral temperature of the furnace roller through dynamic target value control and adjustment of the thermal crown fan power frequency conversion, thereby preventing the strip from deviating and ensuring the stable operation of the strip in the annealing furnace.

[0023] The present invention is not limited to the above-mentioned implementation modes, and anyone should be aware of the structural changes made under the enlightenment of the present invention, and all those having the same or similar technical solutions as the present invention fall within the protection scope of the present invention.

[0024] The techniques, shapes, and structural parts not described in detail in the present invention are all well-known techniques.

Claims

1. A method for accurately controlling the transverse temperature of furnace rollers in the entrance area of ​​the heating section of a continuous annealing furnace, characterized in that: The following steps are involved: 1) Temperature collection: a high temperature radiometer is set at the entrance of the heating section of the annealing furnace to measure the temperature inside the furnace as T f , Strip temperature T s The protective gas in the furnace enters the furnace from the bottom of the furnace, is stirred by the movement of the strip, and heat is transferred between the strip and the radiation tube. The temperature at the end of the furnace roller is T e =1 / 2(T f +T s ), the middle of the furnace roller is in direct contact with the strip steel to generate heat conduction, and heat radiation occurs with the ambient temperature in the furnace. The temperature of the middle of the furnace roller is T c =f(T f , T s ); 2) Establish a temperature model by setting the temperature of the annealing furnace heating section entrance to T f , Strip temperature T s , furnace roller end temperature T e , furnace roller middle temperature T c Track and detect the data, and use data simulation to establish the temperature model of the heating section entrance furnace roller temperature, furnace temperature, and strip temperature; 3) Determine the transverse temperature difference between the end and the middle of the furnace roller under the condition of positive convexity of the furnace roller. Through thermodynamic calculation, ensure that the temperature difference between the end and the middle of the furnace roller convexity is △T=T under the condition of ensuring that the strip does not deviate. e -T c ≤120℃, ensuring stable operation of the strip; 4) Establish an automatic control system, measure the strip temperature, furnace temperature and furnace roller temperature respectively through measuring elements, input the measured values ​​of the corresponding temperature signals into the automatic control system, and compare them with the set values ​​of the temperature control model, and input the obtained deviation values ​​into the controller. The controller controls the thermal crown fan in the furnace through the actuator, adjusts the air volume, and accurately controls the temperature of the area near the furnace roller, thereby realizing accurate control of the lateral temperature of the furnace roller; 5) Accurate transverse temperature control of furnace rollers, transverse temperature difference of furnace rollers △T=T e -T c When △T>120℃, the measuring element feeds back the temperature signal to the automatic control system, and the actuator adjusts the fan air volume until △T=120℃, then the automatic control system stops adjusting to keep the parameters stable; when △T≤120℃, the automatic control system operates normally to keep the strip running stably.

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