Steel belt drying waste heat recovery method, system, equipment and medium

Abstract

The invention relates to a steel belt drying waste heat recovery method, system and device and a medium, and relates to the technical field of steel belt machining, and the method comprises the steps that a rolling temperature compensation value needed by a tail rolling module for eliminating steel belt deformation is calculated according to the steel belt deformation quantity; according to the real-time hot air temperature and the heat loss of the fan, the hot air estimated temperature is obtained through calculation; comparing the hot air estimated temperature with the calendering temperature compensation value, and judging and selecting a drying oven waste heat circulation target; if the hot air estimated temperature is smaller than the calendaring temperature compensation value, hot air of a fan is circulated to the position of an inlet of the drying oven; and if the hot air estimated temperature is not smaller than the calendaring temperature compensation value, the draught fan sends the hot air with the temperature equal to the calendaring temperature compensation value to the steel belt inlet position of the tail calendaring module. According to the system, efficient cyclic utilization of drying waste heat can be achieved, and the energy consumption cost is reduced.

Description

Technical Field

[0001] The present application relates to the field of steel strip processing, and in particular to a method, system, equipment and medium for recovering waste heat from steel strip drying. Background Art

[0002] The production and processing of stainless steel strip has experienced rapid growth in recent years. As a key branch of metal products, it is widely used in industries such as industrial manufacturing, architectural decoration, and automotive manufacturing. During the production process, the steel strip undergoes multiple processing steps, including rolling, cleaning, drying, annealing, and calendering, to meet the performance and surface quality requirements of various downstream customers. The drying process, which primarily removes residual moisture or coating solvents from the surface of the steel strip during cleaning, provides a dry substrate for subsequent annealing or surface treatment, and is a key step in ensuring the quality of the steel strip.

[0003] In existing drying technology, drying equipment typically uses gas or electric heating to generate high-temperature hot air to quickly dry the steel strip. After drying, the large amount of high-temperature waste heat, such as the waste hot air at the oven outlet, is primarily handled in two ways: directly discharged to the outside environment through a chimney; or passively cooled using simple heat dissipation devices such as heat sinks or cooling fans.

[0004] While existing technologies have attempted to recover drying waste heat to some extent, significant deficiencies remain. First, waste heat recovery efficiency is low, with most of the heat energy still wasted through emissions or dissipation, failing to form a closed-loop system with the production process. Second, there is a lack of dynamic monitoring and control mechanisms for waste heat temperature, making it impossible to optimize recovery strategies based on real-time operating conditions, such as hot air flow and temperature fluctuations. Third, heat losses during waste heat transport are not accurately quantified, resulting in a mismatch between the actual usable temperature of recovered heat and the target demand. These issues not only increase energy consumption costs but also fall short of the sustainable development goals of green manufacturing. A controllable drying waste heat recovery technology is urgently needed to improve resource utilization. Summary of the Invention

[0005] The first purpose of this application is to provide a method for recovering waste heat from steel strip drying, which can reasonably allocate the waste heat circulation path of the oven, utilize the waste heat from the oven in other processing procedures or recover it into the oven to improve the heating efficiency of the oven, realize the efficient recycling of the waste heat from drying, and reduce energy consumption costs.

[0006] In the first aspect, the present application provides a method for recovering waste heat from steel strip drying, which adopts the following technical solution: A method for recovering waste heat from steel strip drying, comprising: The hot air from the oven outlet is sent to the steel strip outlet of the middle rolling module and then to the fan; According to the steel strip deformation at the steel strip outlet position of the middle rolling module, the rolling temperature compensation value required by the tail rolling module to eliminate the steel strip deformation is calculated; Calculate the estimated hot air temperature based on the real-time hot air temperature of the fan and the heat loss at the entrance of the steel strip sent to the tail rolling module; Compare the estimated hot air temperature and the calendering temperature compensation value to determine the target of the oven waste heat circulation; If the estimated hot air temperature is lower than the calendering temperature compensation value, the hot air from the fan is circulated to the oven inlet; If the estimated hot air temperature is not less than the calendering temperature compensation value, the fan will send hot air with a temperature equal to the calendering temperature compensation value to the steel strip inlet position of the tail calendering module.

[0007] By adopting the above technical solution, the calendering temperature compensation value can be dynamically adjusted according to the deformation of the steel strip, and the comparison result between the temperature of the hot air entering the tail calendering module and the calendering temperature compensation value can be estimated, and a suitable circulation path of the waste heat of the oven can be selected. When the temperature of the hot air is sufficient to cause the steel strip to deform, the surface of the steel strip is smoothed by heating and calendering, which effectively improves the utilization rate of waste heat, improves the effect of steel strip calendering, and improves product quality; when the hot air temperature does not reach the calendering temperature compensation value, the hot air is circulated back to the inside of the oven, which enhances the heating efficiency of the oven and reduces the waste in the tail calendering module due to the hot air temperature not meeting the requirements for steel strip deformation, thereby reducing the energy consumption of waste heat.

[0008] In a preferred example, the present application may be further configured as follows: the step of calculating the rolling temperature compensation value required to eliminate the steel strip deformation based on the steel strip deformation at the steel strip outlet position of the middle rolling module includes: Establish the mapping relationship between the deformation variable δ of the middle calendering module and the calendering temperature compensation value T, using the formula: T=δ·E / (α·d²), Where E is the elastic modulus of the steel strip, α is the thermal expansion coefficient, and d is the set thickness of the steel strip; When it is detected that the local deformation of the steel strip exceeds the reference value, the gradient compensation mode is triggered and the threshold of the rolling temperature compensation value is increased.

[0009] By adopting the above technical solution, a mapping relationship between the steel strip deformation and the rolling temperature compensation value is established, and a formula is calculated in combination with the steel strip elastic modulus, thermal expansion coefficient and set thickness, thereby achieving accurate quantification of the rolling temperature compensation value, thereby effectively improving the accuracy of steel strip deformation correction; when it is detected that the local deformation of the steel strip exceeds the reference value, the gradient compensation mode is triggered to increase the threshold of the rolling temperature compensation value, further enhancing the adaptability to abnormal deformation of the steel strip and improving the quality stability and consistency of the steel strip during the rolling process.

[0010] In a preferred example, the present application may be further configured as follows: before the step of calculating and obtaining the estimated hot air temperature based on the real-time hot air temperature of the fan and the heat loss at the inlet of the steel strip delivered to the tail rolling module, the step further includes: Calculate the initial temperature T_out of the hot air at the steel strip inlet of the tail rolling module using the formula: T_out=T_in−ΔT=T_in-(U·A·τ·(T_in−T_out)·(1 / (m·c)), Among them, T_in is the real-time hot air temperature, ΔT is the pipeline heat loss, U is the heat transfer coefficient, A is the heat transfer area, τ is the transmission time of hot air in the pipeline, m is the mass of hot air, and c is the specific heat capacity of hot air.

[0011] By adopting the above technical solution, the actual temperature of the steel strip inlet at the tail rolling module when the hot air reaches it is calculated, and the temperature change of the hot air after the pipeline transmission process is quantified, thereby providing reference data for the subsequent selection of the waste heat circulation target.

[0012] In a preferred example, the present application may be further configured as follows: before the step of comparing the hot air estimated temperature and the calendering temperature compensation value to determine and select the oven waste heat circulation target, the step includes: If the initial temperature of the hot air is lower than the calendering temperature compensation value, the heat loss of the pipeline is compensated by changing the fan speed so that the temperature of the hot air at the steel strip inlet of the tail calendering module meets the calendering temperature compensation value; Determine whether the fan speed for compensating for pipeline heat loss exceeds the allowable speed range. If not, update the hot air estimated temperature to the same temperature as the calendering temperature compensation value. If exceeded, update the hot air estimated temperature to the same temperature as the hot air initial temperature.

[0013] By adopting the above technical solution, the actual temperature of the steel strip inlet at the tail calendering module when the hot air reaches the latter is compared with the calendering temperature compensation value. When the hot air temperature is not high enough to cause deformation of the steel strip, the heat loss of the hot air in the transmission pipeline is compensated in combination with the adjustment of the fan speed, so that the hot air reaches the calendering temperature compensation value when it is transmitted to the tail calendering module as much as possible. At the same time, when the fan speed exceeds the allowable range and the fan cannot heat to the calendering temperature compensation value, the hot air is circulated back to the inside of the oven, thereby reducing the waste of hot air in the tail calendering module due to the hot air temperature not meeting the requirements for steel strip deformation, thereby reducing energy consumption.

[0014] In a preferred example, the present application may be further configured as follows: before the step of delivering the hot air from the oven outlet to the steel strip outlet of the middle rolling module and then to the fan, the step further includes: According to the steel strip deformation detection data of the head rolling module set at the steel strip entrance position of the middle rolling module, the rolling pressure of the middle rolling module is dynamically corrected using the formula: P=P0+ΔP=P0+K∫(δ_max-δ_avg)dt, Wherein, P is the rolling pressure value of the middle rolling module, P0 is the pressure value required to roll the steel strip to the set thickness, ΔP is the pressure compensation value, K is the material hardening coefficient, δ_max is the maximum deformation, and δ_avg is the average deformation; The steel strip deformation at the steel strip outlet position of the middle rolling module is updated in real time.

[0015] By adopting the above technical solution and utilizing the integral control method, the rolling pressure of the middle rolling module is adjusted in real time according to the deformation of the steel strip first rolled by the head rolling module. After the secondary rolling, product defects caused by deformation are reduced, and the degree of deformation of the steel strip entering the tail rolling module is reduced, thereby improving the rolling accuracy and surface quality of the steel strip.

[0016] In a preferred example, the present application may be further configured as follows: before the step of delivering the hot air from the oven outlet to the steel strip outlet of the middle rolling module and then to the fan, the step further includes: To establish an oven temperature stability index, use the formula: S=σ(T) / T_avg, Where σ(T) is the standard deviation of temperature, T_avg is the average temperature in the oven; When S is greater than the preset index, if the estimated hot air temperature is not less than the rolling temperature compensation value, the fan is allowed to send hot air with a temperature equal to the rolling temperature compensation value to the steel strip inlet position of the tail rolling module; When S is not greater than the preset index, the hot air from the fan is circulated to the oven inlet, and only the heating device of the tail calendering module is adjusted to heat the steel strip so that the temperature of the steel strip inlet of the tail calendering module reaches the calendering temperature compensation value.

[0017] By adopting the above technical solution, an oven temperature stability index is established and based on the comparison result with the preset index, the hot air conveying path and the heating method of the tail calendering module are dynamically adjusted. Only when the temperature in the oven is stable will the waste heat be circulated to the steel strip inlet position of the tail calendering module, so that the deformation of the steel strip due to heating can be carried out stably, thereby improving the quality of the steel strip.

[0018] In a preferred example, the present application may be further configured as follows: when it is detected that the local deformation of the steel strip exceeds the reference value, the step of triggering the gradient compensation mode and increasing the threshold of the rolling temperature compensation value includes: Obtain the deformation quantity and degree of the steel strip within the detection time and generate a change curve; The fluctuation value of the variation curve is calculated and obtained. If the fluctuation value exceeds a reference value, a gradient compensation mode is triggered to increase the threshold of the rolling temperature compensation value.

[0019] By adopting the above technical solution, comprehensive monitoring of the steel strip deformation trend is achieved, and the gradient compensation mode is triggered in time when the deformation is abnormal, effectively avoiding product quality problems caused by excessive local deformation, and enabling the tail rolling module to be adjusted according to actual needs, thereby improving the accuracy and stability of steel strip deformation repair.

[0020] In a second aspect, the present application provides a steel strip drying waste heat recovery system, which adopts the following technical solution: A steel strip drying waste heat recovery system, comprising: Heat transfer module: used to deliver the hot air from the oven outlet to the steel strip outlet of the middle rolling module and then to the fan; Compensation calculation module: used to calculate the rolling temperature compensation value required by the tail rolling module to eliminate the steel strip deformation according to the steel strip deformation at the steel strip outlet position of the middle rolling module; Temperature estimation module: used to calculate the estimated hot air temperature based on the real-time hot air temperature of the fan and the heat loss at the entrance of the steel strip sent to the tail rolling module; Target selection module: used to compare the hot air estimated temperature and the calendering temperature compensation value to determine and select the oven waste heat circulation target; Oven circulation module: used to circulate the hot air from the fan to the oven inlet if the estimated hot air temperature is lower than the calendering temperature compensation value; Calendering circulation module: If the estimated hot air temperature is not less than the calendering temperature compensation value, the fan will send hot air with a temperature of the calendering temperature compensation value to the steel strip inlet position of the tail calendering module.

[0021] In a third aspect, the present application provides an electronic device, which adopts the following technical solution: An electronic device includes a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the steps of the above-mentioned method for recovering waste heat from drying a steel strip are implemented.

[0022] In a fourth aspect, the present application provides a computer storage medium, including the following technical solutions: A computer-readable storage medium stores a computer program, which, when executed by a processor, implements the steps of the above-mentioned steel strip drying waste heat recovery method.

[0023] In summary, this application has the following beneficial technical effects: This application reasonably distributes the hot air at the outlet of the oven to the tail rolling module according to the temperature of the hot air entering the tail rolling module to improve the effect of eliminating deformation of the steel strip, or directly circulates it back to the inside of the oven to increase the heating efficiency of the oven, thereby realizing efficient recycling of the waste heat from drying, improving the waste heat recovery efficiency, and reducing energy consumption costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a flow chart of a method for recovering waste heat from steel strip drying in one embodiment of the present application.

[0025] Figure 2 This is a flowchart of the sub-steps of step S2 in one embodiment of the present application.

[0026] Figure 3 This is a flowchart of the sub-steps of step S3 in one embodiment of the present application.

[0027] Figure 4 This is a flowchart of the steps added before step S4 in one embodiment of the present application.

[0028] Figure 5 This is a step process added before step S1 in one embodiment of the present application. Figure 1 .

[0029] Figure 6 This is a step process added before step S1 in one embodiment of the present application. Figure 2 .

[0030] Figure 7 This is a flowchart of the sub-steps of step S21 in one embodiment of the present application.

[0031] Figure 8 This is a structural diagram of a steel strip drying waste heat recovery system according to one embodiment of the present application.

[0032] Figure 9 It is a principle block diagram of an electronic device in one embodiment of the present application.

[0033] Reference numerals: 1. heat transfer module; 2. compensation calculation module; 3. temperature estimation module; 4. target selection module; 5. oven circulation module; 6. calendering circulation module. DETAILED DESCRIPTION

[0034] The following is combined with Figure 1-9 This application is described in further detail.

[0035] It should be noted that all actions of obtaining data or information or data in this application are carried out in compliance with the relevant data protection laws and policies of the country where they are located and with the authorization of the corresponding users.

[0036] refer to Figure 1 A method for recovering waste heat from steel strip drying, comprising: S1. Send the hot air from the oven outlet to the steel strip outlet of the middle rolling module and then to the fan.

[0037] Specifically, hot air first enters the steel strip outlet of the central rolling module, preheating the strip. This preheating process, while not requiring a specific hot air temperature, essentially maintains the strip's basic thermal state. Since the strip has already completed its primary forming process, preheating only serves to prevent microstructural degradation caused by a sudden drop in material temperature. This requirement is met by utilizing the residual heat from the oven, representing passive thermal compensation.

[0038] S2. Calculate the rolling temperature compensation value required by the tail rolling module to eliminate the steel strip deformation according to the steel strip deformation at the steel strip outlet position of the middle rolling module.

[0039] Specifically, because deformation at the edges of the steel strip affects product quality, temperature compensation in the final rolling module of the final rolling process must actively intervene in the material's phase transition. The strip deformation directly reflects the stress distribution within the material, and the rolling temperature compensation value must precisely match the material's dynamic rheological properties. The hot air temperature must reach the thermodynamic threshold necessary to eliminate residual stress and reconstruct the lattice structure.

[0040] S3. Calculate and obtain the estimated hot air temperature based on the real-time hot air temperature of the fan and the heat loss at the inlet of the steel strip delivered to the tail rolling module.

[0041] Specifically, the estimated hot air temperature is the estimated hot air temperature from the hot air transmission pipeline at the steel strip outlet position of the middle rolling module to the steel strip inlet position of the tail rolling module, which is calculated based on the heat loss of the hot air in the pipeline.

[0042] S4. Compare the hot air estimated temperature and the calendering temperature compensation value to determine the target of the oven waste heat circulation.

[0043] Specifically, determine whether the waste heat from the oven can be used in the tail calendering step, reasonably adjust the destination of the waste heat, maximize the use of the waste heat from the oven, and improve resource utilization.

[0044] S5. If the estimated hot air temperature is lower than the calendering temperature compensation value, the hot air from the fan is circulated to the oven inlet.

[0045] Specifically, when the hot air reaches the steel strip inlet position of the tail calendering module at a temperature sufficient to cause deformation of the steel strip, the surface of the steel strip is smoothed by heating and calendering, effectively improving the utilization rate of waste heat, the effect of steel strip calendering, and the quality of the product. At the same time, because the steel strip outlet position of the middle calendering module has already preheated the steel strip, when the hot air reaches the calendering temperature compensation value at the steel strip inlet position of the tail calendering module, it can be confirmed that the temperature at the steel strip inlet position of the tail calendering module is sufficient to cause deformation of the steel strip, assisting the tail calendering module to perform a more precise final calendering process on the deformation of the steel strip surface.

[0046] In addition, after the hot air enters the steel strip entrance position of the tail rolling module, it is recycled into the oven through the transmission pipeline. The oven uses the hot air that still has a certain amount of heat to heat it, forming a closed heat circulation loop.

[0047] S6. If the estimated hot air temperature is not less than the rolling temperature compensation value, the fan is used to deliver hot air having a temperature equal to the rolling temperature compensation value to the steel strip inlet position of the rear rolling module.

[0048] Specifically, when the hot air temperature does not reach the rolling temperature compensation value, although the steel strip is preheated at the steel strip exit of the middle rolling module, some heat will be lost from the steel strip exit of the middle rolling module to the steel strip entrance of the rear rolling module. At this time, the superposition of the estimated hot air temperature and the preheated steel strip temperature may not necessarily meet the rolling temperature compensation value. In order to reduce the waste of hot air in the rear rolling module due to the hot air temperature not meeting the steel strip deformation requirements, the hot air is recycled back into the oven. The oven uses the returned hot air to continue heating, thereby enhancing the oven's heating efficiency, forming a closed heat circulation loop, and reducing the energy consumption of waste heat.

[0049] refer to Figure 2 Furthermore, in one embodiment, step S2 is further divided into the following sub-steps: S20, establish a mapping relationship between the deformation variable δ of the middle calendering module and the calendering temperature compensation value T, using the formula: T=δ·E / (α·d²), Where E is the elastic modulus of the steel strip, α is the thermal expansion coefficient, and d is the set thickness of the steel strip.

[0050] Specifically, the local deformation of the steel strip is monitored in real time to obtain δ. The elastic modulus E is the ratio of stress to strain during the elastic deformation phase of a material, defined as E = ϵ / σ, where σ is the applied stress (in Pa) and ϵ is the resulting strain. For various steel strip materials, E generally ≈ 200 GPa for carbon steel and ≈ 190–210 GPa for stainless steel. The specific value needs to be adjusted based on the steel type and heat treatment status.

[0051] By establishing a mapping relationship between the steel strip deformation and the rolling temperature compensation value, and combining the steel strip elastic modulus, thermal expansion coefficient and set thickness to calculate the formula, the rolling temperature compensation value obtained is the thermodynamic threshold to achieve the maximum possible elimination of residual stress and reconstruction of the lattice structure. The thermal expansion coefficient α is a thermodynamic characteristic parameter of the material, which describes the sensitivity of the material to dimensional changes when heated. Generally, the thermal expansion coefficient of steel is α. α ≈11·10−6℃ −1 .

[0052] S21. When it is detected that the local deformation of the steel strip exceeds the reference value, the gradient compensation mode is triggered and the threshold of the rolling temperature compensation value is increased.

[0053] Specifically, the reference value δ0 = k·d, where k is the deformation coefficient allowed by the process. In this embodiment, k is set to 0.01 to 0.05. When δ>δ0, the gradient compensation mode is triggered.

[0054] In this embodiment, β is the gradient compensation coefficient. When the deformation excess ratio δ / δ0≤1.2, the compensation coefficient β=1.1; when 1.2<δ / δ0≤1.5, the compensation coefficient β=1.3; when δ / δ0>1.5, the compensation coefficient β=1.5, and so on, increasing as the deformation excess ratio increases.

[0055] The calculation formula of the original rolling temperature compensation value is adjusted to: T=β·(δ·E) / (α·d²).

[0056] Triggering the gradient compensation mode to increase the threshold of the rolling temperature compensation value can further enhance the adaptability to abnormal deformation of the steel strip and improve the quality stability and consistency of the steel strip during the rolling process.

[0057] In addition, reference Figure 3 Furthermore, in one embodiment, step S3 is further divided into the following sub-steps: S30, calculate and obtain the initial temperature T_out of the hot air actually reaching the steel strip inlet position of the tail rolling module, using the formula: T_out=T_in−ΔT=T_in-(U·A·τ·(T_in−T_out)·(1 / (m·c)), Among them, T_in is the real-time hot air temperature, ΔT is the pipeline heat loss, U is the heat transfer coefficient, A is the heat transfer area, τ is the transmission time of hot air in the pipeline, m is the mass of hot air, and c is the specific heat capacity of hot air.

[0058] Specifically, temperature sensors are installed at the fan and the steel strip inlet of the tail rolling module. The temperature sensors at both locations can provide accurate temperature data to predict in advance the actual temperature of the steel strip inlet where the hot air arrives at the tail rolling module, and provide reference data for selecting the waste heat circulation target in advance.

[0059] In addition, reference Figure 4 Furthermore, in one embodiment, before step S4, steps S40 and S41 are added: S40: If the initial temperature of the hot air is lower than the rolling temperature compensation value, the heat loss of the pipeline is compensated by changing the fan speed so that the temperature of the hot air when it is transmitted to the steel strip inlet position of the rear rolling module meets the rolling temperature compensation value.

[0060] Specifically, if the initial hot air temperature is lower than the rolling temperature compensation value, it will not meet the thermodynamic threshold for eliminating residual stress and reconstructing the lattice structure of the steel strip. Therefore, by adjusting the fan speed, the ability to capture the oven's residual heat is changed, so that the hot air reaches the rolling temperature compensation value as much as possible by the time it is transmitted to the rear rolling module.

[0061] S41. Determine whether the fan speed for compensating for pipeline heat loss exceeds the allowable speed range. If not, update the hot air estimated temperature to the same temperature as the rolling temperature compensation value. If exceeded, update the hot air estimated temperature to the same temperature as the hot air initial temperature.

[0062] Specifically, if the change in fan speed causes the temperature in the oven to fail to meet the desired level, the speed is outside the permissible range. Alternatively, if the fan speed reaches the maximum permissible power, the permissible range is also exceeded.

[0063] When the fan speed exceeds the allowable range, the fan cannot heat the hot air to the calendering temperature compensation value. In this case, the hot air is circulated back into the oven, and the oven heats the hot air at a certain temperature to achieve heat recycling, reducing the waste of hot air in the tail calendering module due to the hot air temperature not meeting the steel strip deformation requirements, thereby reducing heat consumption.

[0064] In addition, reference Figure 5 Furthermore, in one embodiment, before step S1, steps S10 and S11 are added: S10, dynamically correcting the rolling pressure of the middle rolling module according to the steel strip deformation detection data of the head rolling module located at the steel strip entrance of the middle rolling module, using the formula: P=P0+ΔP=P0+K∫(δ_max-δ_avg)dt, Among them, P is the rolling pressure value of the middle rolling module, P0 is the pressure value required to roll the steel strip to the set thickness, ΔP is the pressure compensation value, K is the material hardening coefficient, δ_max is the maximum deformation, and δ_avg is the average deformation.

[0065] Specifically, δ_max is the maximum deformation, and δ_avg is the average deformation, obtained by setting up a sensor array in the middle rolling module. The first rolling process is performed in the head rolling module. After the first rolling process, the steel strip enters the middle rolling module for the second rolling process. This second rolling process can further reduce deformation of the steel strip by reducing product defects caused by deformation.

[0066] S11. Update the steel strip deformation at the steel strip outlet position of the middle rolling module in real time.

[0067] Specifically, after dynamically correcting the rolling pressure of the middle rolling module, the steel strip deformation δ at the steel strip outlet position of the middle rolling module is synchronously updated, and then the rolling temperature compensation value T is adjusted to improve the rolling accuracy and surface quality of the steel strip.

[0068] In addition, reference Figure 6 Furthermore, in one embodiment, before step S1, steps S12, S13, and S14 are added: S12. Establish an oven temperature stability index using the formula: S=σ(T) / T_avg, Where σ(T) is the standard deviation of temperature and T_avg is the average temperature in the oven.

[0069] S13. When S is greater than the preset index, if the estimated hot air temperature is not less than the rolling temperature compensation value, the fan is allowed to deliver hot air with a temperature of the rolling temperature compensation value to the steel strip inlet position of the tail rolling module.

[0070] Specifically, the preset index is user-defined. When S is greater than the preset index, indicating that the current oven temperature is sufficiently stable to support normal operation, the waste heat is circulated to the steel strip inlet of the tail rolling module to assist the tail rolling module in the third rolling of the steel strip. This ensures stable deformation of the steel strip due to heating, thereby improving the quality of the steel strip and increasing the utilization rate of the oven's waste heat. Furthermore, the hot air returned from the tail rolling module does not affect the normal operation of the oven.

[0071] S14. When S is not greater than the preset index, the hot air from the fan is circulated to the oven inlet position, and only the heating device of the tail rolling module is adjusted to heat the steel strip, so that the temperature of the steel strip inlet position of the tail rolling module reaches the rolling temperature compensation value.

[0072] Specifically, when S is not greater than the preset index, if the residual heat of the oven is passed through the tail calendering module which needs to dynamically adjust the hot air temperature, it may affect the normal operation of the oven. By adopting the above technical solution, an oven temperature stability index is established and based on the comparison result with the preset index, the hot air conveying path and the heating method of the tail calendering module are dynamically adjusted. Only when the temperature in the oven is stable will the waste heat be circulated to the steel strip inlet position of the tail calendering module, so that the deformation of the steel strip due to heating can be carried out stably, thereby improving the quality of the steel strip.

[0073] In addition, reference Figure 7 Furthermore, in one embodiment, step S21 is further divided into the following sub-steps: S210. Obtain the deformation amount and deformation degree of the steel strip within the detection time, and generate a change curve.

[0074] Specifically, three sensors are installed at the steel strip exit position of the middle rolling module, one at the center line in the width direction of the steel strip, recorded as the center point; 10% of the width from the left edge of the steel strip, recorded as the left point; and 10% of the width from the right edge of the steel strip, recorded as the right point.

[0075] Furthermore, the deformation variables of three points are collected in real time at a fixed frequency. Combined with the running speed of the steel belt, the time data is converted into position data to generate the horizontal (left point, center point, right point) and longitudinal (changing with time) deformation curves.

[0076] S211. Calculate and obtain the fluctuation value of the change curve. If the fluctuation value exceeds the reference value, trigger the gradient compensation mode and increase the threshold of the rolling temperature compensation value.

[0077] Specifically, the standard deviation of the deformation variables at the three points is calculated to measure the difference in lateral deformation. The standard deviation of the data at the center point over 10 consecutive seconds is taken to measure the fluctuation in the time dimension. A baseline value for fluctuation is also set. In this example, the baseline value is set at 0.3% of the steel strip thickness for lateral fluctuation and 0.5% for longitudinal fluctuation.

[0078] If the lateral or longitudinal fluctuation exceeds the reference value, it is judged as abnormal. Among them, the lateral excess is to locate the compensation area according to the left / right side data; the longitudinal excess is to expand the compensation area along the direction of steel strip movement.

[0079] Next, temperature compensation is performed according to the calculation formula of the rolling temperature compensation value in the gradient compensation mode, so as to effectively avoid product quality problems caused by excessive local deformation, so that the tail rolling module can be adjusted according to the actual steel strip deformation, thereby improving the accuracy and stability of steel strip deformation elimination.

[0080] It should be understood that the size of the serial numbers of the steps in the above embodiments does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

[0081] The embodiment of the present application also provides a steel strip drying waste heat recovery system, which corresponds one-to-one to the steel strip drying waste heat recovery method in the embodiment.

[0082] refer to Figure 8 A steel strip drying waste heat recovery system includes: a heat transfer module 1, a compensation calculation module 2, a temperature estimation module 3, a target selection module 4, an oven circulation module 5, and a calendering circulation module 6. The functional modules are described in detail as follows: A steel strip drying waste heat recovery system, comprising: Heat transfer module 1: used to deliver the hot air from the oven outlet to the steel strip outlet of the middle rolling module and then to the fan.

[0083] Compensation calculation module 2: used to calculate the rolling temperature compensation value required by the tail rolling module to eliminate the steel strip deformation based on the steel strip deformation at the steel strip outlet position of the middle rolling module.

[0084] Temperature estimation module 3: used to calculate and obtain the estimated hot air temperature based on the real-time hot air temperature of the fan and the heat loss at the inlet position of the steel strip sent to the tail rolling module.

[0085] Target selection module 4: used to compare the hot air estimated temperature and the calendering temperature compensation value to determine and select the oven waste heat circulation target.

[0086] Oven circulation module 5: used to circulate the hot air from the fan to the oven inlet if the estimated hot air temperature is lower than the calendering temperature compensation value.

[0087] Calendering circulation module 6: used to make the fan deliver hot air with a temperature equal to the calendering temperature compensation value to the steel strip inlet position of the tail calendering module if the estimated hot air temperature is not less than the calendering temperature compensation value.

[0088] Among them, the heat transfer module 1 can send the hot air from the oven outlet to the steel strip outlet position of the middle rolling module and transport it to the fan, and wait for the diversion decision of the heat circulation path of the target selection module 4 from the fan, so that the waste heat of the oven can be reasonably and effectively transferred and circulated; the compensation calculation module 2 dynamically adjusts the rolling temperature compensation value required by the tail rolling module according to the deformation of the steel strip, so as to improve the accuracy of eliminating the deformation of the steel strip; the temperature estimation module 3 combines the real-time hot air temperature and heat loss of the fan, and calculates the steel strip inlet position of the hot air entering the tail rolling module The estimated temperature at the time of the hot air heating is used to provide a basis for the subsequent circulation path diversion decision; the target selection module 4 selects the appropriate oven waste heat circulation path by comparing the hot air estimated temperature with the calendering temperature compensation value, thereby improving the utilization efficiency of the oven waste heat; when the hot air temperature meets the calendering requirements, the calendering circulation module 5 sends the hot air to the steel strip entrance position of the tail calendering module, using the waste heat to assist in calendering, improving the flatness and processing quality of the steel strip; and when the hot air temperature is insufficient, the oven circulation module 6 re-introduces the hot air to the oven entrance, enhancing the oven heating effect and minimizing heat waste. Through the combination of these modules, the utilization rate of the oven waste heat is effectively improved, and the steel strip calendering process is optimized by heating the steel strip, reducing energy consumption, and improving the surface quality of the steel strip and production stability.

[0089] For the specific definition of the steel strip drying waste heat recovery system, please refer to the definition of the steel strip drying waste heat recovery method in the context, which will not be repeated here. Each module in the above-mentioned steel strip drying waste heat recovery system can be implemented in whole or in part by software, hardware and their combination. The above-mentioned modules can be embedded in or independent of the processor in the electronic device in the form of hardware, or can be stored in the memory of the electronic device in the form of software, so that the processor can call and execute the operations corresponding to the above modules. In one embodiment, an electronic device is provided, which is a user terminal. Reference Figure 9 The electronic device includes a processor, a memory, a network interface, and a database connected via a system bus. The processor of the electronic device is used to provide computing and control capabilities. The memory of the electronic device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system, a computer program, and a database. The internal memory provides an environment for the operation of the operating system and computer program in the non-volatile storage medium. The database of the electronic device is used to store a detection data table. The network interface of the electronic device is used to communicate with an external terminal via a network connection. When the computer program is executed by the processor, a method for recovering waste heat from drying a steel strip is implemented.

[0090] In one embodiment, an electronic device is provided, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the following steps are performed: S1. Send the hot air from the oven outlet to the steel strip outlet of the middle rolling module and then to the fan.

[0091] S2. Calculate the rolling temperature compensation value required by the tail rolling module to eliminate the steel strip deformation according to the steel strip deformation at the steel strip outlet position of the middle rolling module.

[0092] S3. Calculate and obtain the estimated hot air temperature based on the real-time hot air temperature of the fan and the heat loss at the inlet of the steel strip delivered to the tail rolling module.

[0093] S4. Compare the hot air estimated temperature and the calendering temperature compensation value to determine the target of the oven waste heat circulation.

[0094] S5. If the estimated hot air temperature is lower than the calendering temperature compensation value, the hot air from the fan is circulated to the oven inlet.

[0095] S6. If the estimated hot air temperature is not less than the rolling temperature compensation value, the fan is used to deliver hot air having a temperature equal to the rolling temperature compensation value to the steel strip inlet position of the rear rolling module.

[0096] In one embodiment, the sub-steps of step S2 include: S20, establish a mapping relationship between the deformation variable δ of the middle calendering module and the calendering temperature compensation value T, using the formula: T=δ·E / (α·d²), Where E is the elastic modulus of the steel strip, α is the thermal expansion coefficient, and d is the set thickness of the steel strip.

[0097] S21. When it is detected that the local deformation of the steel strip exceeds the reference value, the gradient compensation mode is triggered and the threshold of the rolling temperature compensation value is increased.

[0098] In one embodiment, the detailed sub-steps of step S3 include: S30, calculate and obtain the initial temperature T_out of the hot air actually reaching the steel strip inlet position of the tail rolling module, using the formula: T_out=T_in−ΔT=T_in-(U·A·τ·(T_in−T_out)·(1 / (m·c)), Among them, T_in is the real-time hot air temperature, ΔT is the pipeline heat loss, U is the heat transfer coefficient, A is the heat transfer area, τ is the transmission time of hot air in the pipeline, m is the mass of hot air, and c is the specific heat capacity of hot air.

[0099] In one embodiment, the steps added before step S4 include: S40: If the initial temperature of the hot air is lower than the rolling temperature compensation value, the heat loss of the pipeline is compensated by changing the fan speed so that the temperature of the hot air when it is transmitted to the steel strip inlet position of the rear rolling module meets the rolling temperature compensation value.

[0100] S41. Determine whether the fan speed for compensating for pipeline heat loss exceeds the allowable speed range. If not, update the hot air estimated temperature to the same temperature as the rolling temperature compensation value. If exceeded, update the hot air estimated temperature to the same temperature as the hot air initial temperature.

[0101] In one embodiment, the steps added before step S1 include: S10, dynamically correcting the rolling pressure of the middle rolling module according to the steel strip deformation detection data of the head rolling module located at the steel strip entrance of the middle rolling module, using the formula: P=P0+ΔP=P0+K∫(δ_max-δ_avg)dt, Among them, P is the rolling pressure value of the middle rolling module, P0 is the pressure value required to roll the steel strip to the set thickness, ΔP is the pressure compensation value, K is the material hardening coefficient, δ_max is the maximum deformation, and δ_avg is the average deformation.

[0102] S11. Update the steel strip deformation at the steel strip outlet position of the middle rolling module in real time.

[0103] In one embodiment, the steps added before step S1 include: S12. Establish an oven temperature stability index using the formula: S=σ(T) / T_avg, Where σ(T) is the standard deviation of temperature and T_avg is the average temperature in the oven.

[0104] S13. When S is greater than the preset index, if the estimated hot air temperature is not less than the rolling temperature compensation value, the fan is allowed to deliver hot air with a temperature of the rolling temperature compensation value to the steel strip inlet position of the tail rolling module.

[0105] S14. When S is not greater than the preset index, the hot air from the fan is circulated to the oven inlet position, and only the heating device of the tail rolling module is adjusted to heat the steel strip, so that the temperature of the steel strip inlet position of the tail rolling module reaches the rolling temperature compensation value.

[0106] In one embodiment, the sub-steps of step S21 include: S210. Obtain the deformation amount and deformation degree of the steel strip within the detection time, and generate a change curve.

[0107] S211. Calculate and obtain the fluctuation value of the change curve. If the fluctuation value exceeds the reference value, trigger the gradient compensation mode and increase the threshold of the rolling temperature compensation value.

[0108] Those skilled in the art will appreciate that all or part of the processes in the above-described method embodiments can be implemented by instructing the relevant hardware through a computer program. The computer program can be stored in a non-volatile computer-readable storage medium. When executed, the computer program can include the processes of the above-described method embodiments. Any reference to memory, storage, database, or other media used in the various embodiments provided herein may include non-volatile and / or volatile memory. Non-volatile memory may include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM), or flash memory. Volatile memory may include random access memory (RAM) or external cache memory. By way of illustration and not limitation, RAM is available in various forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDRSDRAM), enhanced SDRAM (ESDRAM), synchronous link DRAM (SLDRAM), RAMbus direct RAM (RDRAM), direct RAMbus dynamic RAM (DRDRAM), and RAMbus dynamic RAM (RDRAM).

[0109] Those skilled in the art will clearly understand that for the sake of convenience and brevity of description, only the division of the above-mentioned functional units and modules is used as an example. In actual applications, the above-mentioned functions can be distributed and completed by different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above.

Claims

1. A method for recovering waste heat from steel strip rolling and drying, characterized in that: include: The hot air from the oven outlet is sent to the steel strip outlet of the middle rolling module and then to the fan; According to the steel strip deformation at the steel strip outlet position of the middle rolling module, the rolling temperature compensation value required by the tail rolling module to eliminate the steel strip deformation is calculated; Calculate the estimated hot air temperature based on the real-time hot air temperature of the fan and the heat loss at the entrance of the steel strip sent to the tail rolling module; Compare the estimated hot air temperature and the calendering temperature compensation value to determine the target of the oven waste heat circulation; If the estimated hot air temperature is lower than the calendering temperature compensation value, the hot air from the fan is circulated to the oven inlet; If the estimated hot air temperature is not less than the calendering temperature compensation value, the fan will send hot air with a temperature equal to the calendering temperature compensation value to the steel strip inlet position of the tail calendering module.

2. The method according to claim 1, characterized in that The step of calculating the rolling temperature compensation value required to eliminate the steel strip deformation based on the steel strip deformation at the steel strip outlet position of the middle rolling module includes: Establish the mapping relationship between the deformation variable δ of the middle calendering module and the calendering temperature compensation value T, using the formula: T=δ·E / (α·d²), Where E is the elastic modulus of the steel strip, α is the thermal expansion coefficient, and d is the set thickness of the steel strip; When it is detected that the local deformation of the steel strip exceeds the reference value, the gradient compensation mode is triggered and the threshold of the rolling temperature compensation value is increased.

3. The method according to claim 2, characterized in that Before the step of calculating and obtaining the estimated hot air temperature based on the real-time hot air temperature of the fan and the heat loss at the inlet position of the steel strip delivered to the tail rolling module, the method further includes: Calculate the initial temperature T_out of the hot air at the steel strip inlet of the tail rolling module using the formula: T_out=T_in−ΔT=T_in-(U·A·τ·(T_in−T_out)·(1 / (m·c)), Among them, T_in is the real-time hot air temperature, ΔT is the pipeline heat loss, U is the heat transfer coefficient, A is the heat transfer area, τ is the transmission time of hot air in the pipeline, m is the mass of hot air, and c is the specific heat capacity of hot air.

4. The method according to claim 3, characterized in that Before the step of comparing the hot air estimated temperature and the calendering temperature compensation value to determine and select the oven waste heat circulation target, the method includes: If the initial temperature of the hot air is lower than the calendering temperature compensation value, the heat loss in the pipeline is compensated by changing the fan speed so that the temperature of the hot air at the steel strip inlet of the tail calendering module meets the calendering temperature compensation value; Determine whether the fan speed for compensating for pipeline heat loss exceeds the allowable speed range. If not, update the hot air estimated temperature to the same temperature value as the calendering temperature compensation value. If exceeded, update the hot air estimated temperature to the same temperature value as the hot air initial temperature.

5. The method according to claim 1, wherein Before the step of delivering the hot air from the oven outlet to the steel strip outlet of the middle rolling module and then to the fan, the method further includes: According to the steel strip deformation detection data of the head rolling module set at the steel strip entrance position of the middle rolling module, the rolling pressure of the middle rolling module is dynamically corrected using the formula: P=P0+ΔP=P0+K∫(δ_max-δ_avg)dt, Wherein, P is the rolling pressure value of the middle rolling module, P0 is the pressure value required to roll the steel strip to the set thickness, ΔP is the pressure compensation value, K is the material hardening coefficient, δ_max is the maximum deformation, and δ_avg is the average deformation; The steel strip deformation at the steel strip outlet position of the middle rolling module is updated in real time.

6. The method according to claim 1, characterized in that Before the step of delivering the hot air from the oven outlet to the steel strip outlet of the middle rolling module and then to the fan, the method further includes: To establish an oven temperature stability index, use the formula: S=σ(T) / T_avg, Where σ(T) is the standard deviation of temperature, T_avg is the average temperature in the oven; When S is greater than the preset index, if the estimated hot air temperature is not less than the rolling temperature compensation value, the fan is allowed to send hot air with a temperature equal to the rolling temperature compensation value to the steel strip inlet position of the tail rolling module; When S is not greater than the preset index, the hot air from the fan is circulated to the oven inlet, and only the heating device of the tail calendering module is adjusted to heat the steel strip so that the temperature of the steel strip inlet of the tail calendering module reaches the calendering temperature compensation value.

7. The method according to claim 2, characterized in that The step of triggering the gradient compensation mode and increasing the threshold of the rolling temperature compensation value when detecting that the local deformation of the steel strip exceeds the reference value includes: Obtain the deformation amount and degree of the steel strip within the detection time and generate a change curve; The fluctuation value of the variation curve is calculated and obtained. If the fluctuation value exceeds a reference value, a gradient compensation mode is triggered to increase the threshold of the rolling temperature compensation value.

8. A steel strip rolling and drying waste heat recovery system, characterized in that: include: Heat transfer module (1): used to transfer the hot air from the oven outlet to the steel strip outlet of the middle rolling module and then to the fan; Compensation calculation module (2): used to calculate the rolling temperature compensation value required by the tail rolling module to eliminate the steel strip deformation according to the steel strip deformation at the steel strip outlet position of the middle rolling module; Temperature estimation module (3): used to calculate and obtain the estimated hot air temperature based on the real-time hot air temperature of the fan and the heat loss at the inlet position of the steel strip sent to the tail rolling module; Target selection module (4): used to compare the hot air estimated temperature and the calendering temperature compensation value, and determine and select the oven waste heat circulation target; Oven circulation module (5): used for circulating the hot air from the fan to the oven inlet position if the estimated hot air temperature is lower than the calendering temperature compensation value; Calendering circulation module (6): used to make the fan deliver hot air with a temperature equal to the calendering temperature compensation value to the steel strip inlet position of the tail calendering module if the estimated temperature of the hot air is not less than the calendering temperature compensation value.

9. An electronic device, characterized in that: The method comprises a memory and a processor, wherein the memory stores a computer program that can be loaded by the processor and executes the method for recovering waste heat from steel strip rolling and drying as claimed in any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that A computer program is stored which can be loaded by a processor and executes the method for recovering waste heat from steel strip rolling and drying as claimed in any one of claims 1 to 7.

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