Method for predicting LF target temperature and dynamically calculating power-on duration of ladle furnace

Abstract

The invention relates to a method for predicting the LF target temperature and dynamically calculating the power-on duration of a ladle furnace. The method comprises the following steps that S1, the large ladle continuous casting remaining pouring time is calculated in real time; s2, the large ladle casting temperature of the continuous casting pouring position is predicted; s3, calculating the maximum time from LF leaving to continuous casting top pouring; s4, LF smelting completion processing bit waiting rhythm time is recommended; s5, calculating the maximum smelting time of the LF; s6, predicting the LF target temperature in real time; s7, during each time of temperature measurement, triggering dynamic calculation of the time from the current temperature measurement to the station leaving moment; s8, during temperature measurement each time, the temperature needing to be increased during electrode heating is triggered and dynamically calculated; s9, during each time of temperature measurement, triggering dynamic calculation of electrifying duration of electrode heating; and S10, the calculated power-on duration is issued to the first-level PLC. According to the method, the electrifying duration can be dynamically calculated, it is guaranteed that the steel ladle reaches the temperature required by continuous casting, and the situations that casting is stopped due to insufficient temperature, and production is not stable and smooth are avoided.

Description

Technical Field

[0001] The invention relates to the field of steelmaking ladle furnace production, and more specifically to a method for predicting LF target temperature and dynamically calculating power-on time of a ladle furnace. Background Art

[0002] Refining furnace is a kind of smelting equipment in the hot processing industry. It is mostly used in the process of final deoxidation and alloying of molten steel in ferrous metallurgy, molten steel refining, and can adjust the temperature of molten steel, process buffer, and meet the requirements of continuous casting and continuous rolling. LF refining is an important link in steelmaking production and is of great significance to the production of low-sulfur steel.

[0003] LF is the ladle refining furnace, which uses electrode heating to adjust the composition and temperature. From refining furnace to continuous casting. Since the continuous casting process is the continuous casting of molten steel from multiple furnaces, the supply of molten steel cannot be interrupted. Therefore, before the current casting furnace is finished, the overhead crane must lift the molten steel that has been processed in the previous process and meet the molten steel temperature and composition requirements for continuous casting, otherwise a pouring interruption accident will occur. Of course, in the production process, if the molten steel in the previous process cannot reach the continuous casting, you can consider reducing the continuous casting speed, but this will cause the continuous casting speed to be unstable, affect the quality of the ingot, and cannot meet the typical constant pulling speed requirements. When there are water changes or other abnormal problems in continuous casting, and the pulling speed must be adjusted, the previous process must adjust the exit temperature according to the pulling speed.

[0004] In summary, in the existing steelmaking production process, the poor quality of the ingot is caused by the poor control of the production rhythm from the refining furnace to the continuous casting process. In the current steelmaking production process, especially in the process from the refining furnace to the continuous casting process, there are the following technical problems that need to be solved urgently:

[0005] (1) The ladle furnace is processed too early, and the waiting time is too long during continuous casting, resulting in the pouring temperature not meeting the casting requirements.

[0006] (2) The ladle furnace is treated too late and for too long, resulting in the interruption of continuous casting molten steel.

[0007] (3) When an abnormal speed reduction occurs, the exit target temperature cannot be automatically predicted, and the power-on time cannot be dynamically calculated.

[0008] (4) Generally, the production rhythm is controlled manually or semi-automatically in real time, which not only affects the concentration of vacuum furnace operation, but also may lead to wrong decisions due to various other matters, resulting in unstable production in the steel plant. Summary of the invention

[0009] The technical problem to be solved by the present invention is to provide a method for predicting the LF target temperature of a ladle furnace and dynamically calculating the power-on time. The dynamic calculation of the power-on time can be used to ensure that the ladle reaches the temperature required for continuous casting, thereby avoiding the situation where the casting is interrupted due to insufficient temperature and unstable production.

[0010] The technical solution adopted by the present invention to solve the technical problem is: constructing a method for predicting the LF target temperature of a ladle furnace and dynamically calculating the power-on time, comprising the following steps:

[0011] S1. Real-time calculation of the remaining pouring time of ladle continuous casting;

[0012] S2, predict the pouring temperature of the ladle at the continuous casting pouring position;

[0013] S3, calculate the maximum time from LF leaving the station to continuous casting pouring;

[0014] S4, recommended waiting time for LF smelting completion processing position;

[0015] S5. Calculate the maximum smelting time of LF;

[0016] S6, real-time prediction of LF target temperature;

[0017] S7. Each time the temperature is measured, the time from the current temperature measurement to the departure time is triggered to be dynamically calculated;

[0018] S8, each time the temperature is measured, triggering the dynamic calculation of the temperature that needs to be raised for electrode heating;

[0019] S9, each time the temperature is measured, trigger the dynamic calculation of the power-on time of the electrode heating;

[0020] S10, sending the calculated power-on time to the first-level PLC.

[0021] According to the above scheme, in step S1, the method for real-time calculation of the remaining pouring time of ladle continuous casting includes:

[0022] Get the corresponding continuous casting process according to the continuous casting machine number in the current furnace plan information, and then query the pouring remaining weight W, total casting speed V, billet thickness H, bottom width L, billet density P of the continuous casting furnace; calculate the remaining pouring time t of the large ladle continuous casting 连铸剩余 The formula is as follows:

[0023] t 连铸剩余 =W / (V*H*L*P).

[0024] According to the above scheme, in step S2, the continuous casting pouring position ladle pouring temperature T is predicted. 浇注 The methods include:

[0025] According to the steel grade of the current furnace, query the steel grade standard and obtain the liquidus temperature T of continuous casting. 液相温度 and superheat T 过热度 , and then through historical data machine learning, the natural temperature drop y during the process of pouring molten steel from the large ladle into the medium ladle is obtained 大包-中包温降 ; Dynamically calculate the pouring temperature T of the ladle at regular intervals 开浇温度 , the formula is as follows:

[0026] T 开浇温度 =T 液相温度 +T 过热度 +t 连铸剩余 y 大包-中包温降 .

[0027] According to the above scheme, in step S3, the maximum time t from LF leaving the station to continuous casting pouring is calculated. ccm The methods include:

[0028] According to the historical big data analysis, the transfer time t from LF to the corresponding continuous casting 转运 , if the remaining pouring time of ladle continuous casting is t 连铸剩余 >t 转运 , then t ccm =t 连铸剩余 .

[0029] According to the above scheme, in step S4, it is necessary to wait for the rhythm time t 等待 =t 连铸剩余 -t 转运 .

[0030] According to the above scheme, in step S5, the maximum smelting time t LF最大冶炼 =t ccm .

[0031] According to the above scheme, in step S6, the method for real-time prediction of the LF target temperature includes:

[0032] Through machine learning of a large amount of historical data, it is found that the temperature drop from LF leaving the station to continuous casting pouring is y LF-CMM转运温降 , and then dynamically calculate the LF target temperature T in real time LF目标温度 , the formula is as follows:

[0033] T LF目标温度 =T 开浇温度+ t ccm y LF-CMM转运温降 .

[0034] According to the above scheme, in step S7, each time the temperature is measured, the time from the current temperature measurement to the time of leaving the station is triggered to dynamically calculate tcurrent temperature measurement to leaving the station. First, the smelting time tentrance to temperature measurement time during the temperature measurement is calculated by subtracting the temperature measurement time from the current time. The formula is as follows:

[0035] t 当前测温到离站 =t LF最大冶炼 -t 进站到测温时刻 .

[0036] According to the above scheme, in step S8, each time the temperature is measured, the temperature T required to be raised for electrode heating is triggered to be dynamically calculated. 电极要升温的温度 , get the current temperature T 当前温度 , and after collecting a large amount of historical data, the average natural temperature drop of the smelting process can be obtained through machine learning parameters 平均自然温降 ;

[0037] The temperature rise required for electrode heating is calculated by the following formula:

[0038] T 电极要升温的温度 =T LF目标温度 -T 当前温度 +t 当前测温到离站 *y 平均自然温降 .

[0039] According to the above scheme, in step S9, the power-on time t of electrode heating is calculated by the following formula:

[0040] t=(T 液相温度 +T 过热度 +t 连铸剩余 y 大包-中包温降 +t ccm y LF-CMM转运温降 -T 当前温度 +t 当前测温到离站 *y 平均自然温降 ) / D 电机升温效率

[0041] Among them, D 电机升温效率 Electrode heating efficiency for each electrification strategy.

[0042] The method for predicting the LF target temperature and dynamically calculating the power-on time of the ladle furnace of the present invention has the following beneficial effects:

[0043] 1. The present invention can realize dynamic prediction of the maximum smelting time of LF, avoid errors caused by manual calculation and manual verification, and guide operators to complete LF production within an effective time.

[0044] 2. The present invention can automatically recommend and adjust the waiting time of the ladle furnace after the LF smelting is completed when the production rhythm is sufficient, so as to avoid excessive temperature drop caused by too long waiting time for the completion of LF smelting. It also considers automatically compressing the time of subsequent process steps when the production rhythm is tight, and automatically adjusting the departure target temperature and power-on time.

[0045] 3. The present invention can dynamically adjust the LF departure target and automatically calculate the power-on time, while taking into account the temperature influence of production rhythm adjustment, to avoid the problem of insufficient temperature rise and failure to meet the continuous casting start temperature due to manual calculation. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] The present invention will be further described below with reference to the accompanying drawings and embodiments, in which:

[0047] Figure 1 It is a flow chart of the method for predicting LF target temperature and dynamically calculating power-on time of a ladle furnace according to the present invention. DETAILED DESCRIPTION

[0048] In order to have a clearer understanding of the technical features, purposes and effects of the present invention, specific embodiments of the present invention are now described in detail with reference to the accompanying drawings.

[0049] like Figure 1 As shown, the method for predicting the LF target temperature and dynamically calculating the power-on time of the ladle furnace of the present invention comprises the following steps:

[0050] S1: Real-time calculation of the remaining pouring time t of ladle continuous casting 连铸剩余 According to the continuous casting machine number in the current furnace plan information, the corresponding continuous casting process can be obtained, and then the pouring remaining weight W, total casting speed V, billet thickness H, bottom width L, and billet density P of the continuous casting furnace can be queried. Since the background program calculates the continuous casting remaining pouring time every 5 seconds,

[0051] Formula: t 连铸剩余 =W / (V*H*L*P). From the formula, we can know that the remaining time of continuous casting is proportional to the remaining weight of the casting and inversely proportional to the casting speed. And if there is an abnormality in production that makes it impossible to cast or other abnormalities, t 连铸剩余 Still continue to calculate in real time.

[0052] S2: Predict the pouring temperature T of the continuous casting ladle 浇注 , query the steel grade standard according to the current furnace steel grade, and obtain the liquidus temperature T of continuous casting 液相温度 and superheat T 过热度 , and then through a large amount of historical data machine learning, the natural temperature drop y of the process of pouring molten steel from the large ladle into the medium ladle is obtained 大包-中包温降 (Unit: °C / min). The ladle pouring temperature T is calculated dynamically at a fixed time. 开浇温度 ,

[0053] Formula:T 开浇温度 =T 液相温度 +T 过热度 +t 连铸剩余 y 大包-中包温降 , it can be seen from the formula that due to the remaining time t 连铸剩余It decreases with time, so the temperature of pouring large bags also decreases with time.

[0054] S3: Calculate the maximum time t from LF leaving the station to continuous casting pouring ccm , according to the historical big data analysis, the transfer time t from LF to the corresponding continuous casting 转运 ,

[0055] If the remaining pouring time of ladle continuous casting is t 连铸剩余 >t 转运 , then t ccm =t 连铸剩余 If the LF leaves the station at this time, the transfer time does not need to be considered. And the remaining pouring time of the ladle continuous casting must be greater than the transfer time, otherwise the pouring will be interrupted. 连铸剩余 >t 转运 It also shows that the LF production rhythm is sufficient and there is enough time to transfer. After the LF smelting is completed, the ladle furnace needs to wait for a certain rhythm time at the processing position before leaving the station for continuous casting. It needs to wait for a rhythm time t 等待 =t 连铸剩余 -t 转运 During the waiting period, the ladle also has a certain drop in molten steel temperature.

[0056] S4: Recommended waiting time t for LF smelting completion processing 等待 , if t 连铸剩余 >t 转运 It also shows that the LF production rhythm is sufficient and there is enough time to transfer. After the LF smelting is completed, the ladle furnace needs to wait for a certain rhythm time at the processing position before leaving the station for continuous casting. It needs to wait for a rhythm time t 等待 =t 连铸剩余 -t 转运 During the waiting period, the ladle also has a certain drop in molten steel temperature.

[0057] S5: Calculate the maximum smelting time t of LF LF最大冶炼 , formula: t LF最大冶炼 =t ccm , it means that the LF smelting time must be the maximum time t from LF leaving the station to continuous casting. ccm The smelting must be completed within the time, otherwise the casting will be interrupted.

[0058] S6: Real-time prediction of LF target temperature T LF目标温度 Through a large amount of historical data machine learning, it is found that the temperature drop from LF leaving the station to continuous casting pouring is y LF-CMM转运温降 (Unit: °C / min), and then dynamically calculate the LF target temperature in real time.

[0059] Formula: T LF目标温度 =T 开浇温度+ t ccm y LF-CMM转运温降, due to the pouring temperature T 开浇温度 It decreases with time, so the LF target temperature decreases with time.

[0060] S7: Each time the temperature is measured, the time t from the current temperature measurement to the time of leaving the station is triggered to be dynamically calculated 当前测温到离站 First, calculate the smelting time t when measuring temperature 进站到测温时刻 Subtract the temperature measurement time from the current time.

[0061] Formula: t 当前测温到离站 =t LF最大冶炼 -t 进站到测温时刻 ; if t 进站到测温时刻 >0 indicates that there is a temperature drop during the LF smelting process. If t 进站到测温时刻 <0 indicates that the LF smelting rhythm is tight, the temperature measurement from t to leaving the station is a negative value, the subsequent smelting steps are shortened, and the LF leaving station target temperature increases dynamically.

[0062] S8: Each time the temperature is measured, the temperature T required for electrode heating is dynamically calculated. 电极要升温的温度 , get the current temperature T 当前温度 , and after collecting a large amount of historical data, the average natural temperature drop of the smelting process can be obtained through machine learning parameters 平均自然温降 (Unit: °C / min).

[0063] Formula: T 电极要升温的温度 =T LF目标温度 -T 当前温度 +t 当前测温到离站 *y 平均自然温降

[0064] S9: Each time the temperature is measured, the power-on time t of the electrode heating is dynamically calculated.

[0065] Formula: T 要升温的温度 =D 电机升温效率 *t, where LF smelting electrode heating generally adopts stable fixed voltage block, current block, electrode block or impedance, so after collecting a large amount of historical data, machine learning can be used to learn the electrode heating efficiency of each power-on strategy D 电机升温效率 (Unit: °C / min). Calculate the power-on time required to increase the temperature of the electrode.

[0066] Formula: t = T 要升温的温度 / D 电机升温效率 .

[0067] Combining the above formulas, each time the temperature is measured, the electrode power-on time is calculated.

[0068] t=(T 液相温度 +T 过热度 +t 连铸剩余 y 大包-中包温降 +tccm y LF-CMM转运温降 -T 当前温度 +t 当前测温到离站 *y 平均自然温降 ) / D 电机升温效率

[0069] S10: The calculated power-on time is automatically sent to the first-level PLC. After the first-level PLC receives the instruction and confirms it by the operator, it automatically starts heating according to the set power-on time.

[0070] The embodiments of the present invention are described above in conjunction with the accompanying drawings, but the present invention is not limited to the above-mentioned specific implementation modes, which are merely illustrative rather than restrictive. Under the guidance of the present invention, ordinary technicians in this field can also make many forms without departing from the scope of protection of the present invention and the claims, all of which are within the protection of the present invention.

Claims

1. A method for predicting LF target temperature and dynamically calculating power-on time of a ladle furnace, characterized in that: The following steps are involved: S1. Real-time calculation of the remaining pouring time of ladle continuous casting; S2, predict the pouring temperature of the ladle at the continuous casting pouring position; S3, calculate the maximum time from LF leaving the station to continuous casting pouring; S4, recommended waiting time for LF smelting completion processing position; S5. Calculate the maximum smelting time of LF; S6, real-time prediction of LF target temperature; S7. Each time the temperature is measured, the time from the current temperature measurement to the time of leaving the station is triggered to be dynamically calculated; S8, each time the temperature is measured, triggering the dynamic calculation of the temperature that needs to be raised for electrode heating; S9, each time the temperature is measured, trigger the dynamic calculation of the power-on time of the electrode heating; S10, sending the calculated power-on time to the first-level PLC.

2. The method for predicting LF target temperature and dynamically calculating power-on duration of a ladle furnace according to claim 1, characterized in that: In step S1, the method for calculating the remaining pouring time of ladle continuous casting in real time includes: Get the corresponding continuous casting process according to the continuous casting machine number in the current furnace plan information, and then query the pouring remaining weight W, total casting speed V, billet thickness H, bottom width L, billet density P of the continuous casting furnace; calculate the remaining pouring time t of the large ladle continuous casting 连铸剩余 The formula is as follows: t 连铸剩余＝ W / (V*H*L*P)。 3. The method for predicting LF target temperature and dynamically calculating power-on duration of a ladle furnace according to claim 2, characterized in that: In step S2, the pouring temperature T of the continuous casting ladle is predicted. 浇注 The methods include: According to the steel grade of the current furnace, query the steel grade standard and obtain the liquidus temperature T of continuous casting. 液相温度 and superheat T 过热度 , and then through historical data machine learning, the natural temperature drop y during the process of pouring molten steel from the large ladle into the medium ladle is obtained 大包-中包温降 ; Dynamically calculate the ladle pouring temperature T at regular intervals 开浇温度 , the formula is as follows: T 开浇温度 =T 液相温度 +T 过热度 +t 连铸剩余 y 大包-中包温降 。 4. The method for predicting LF target temperature and dynamically calculating power-on duration of a ladle furnace according to claim 3, characterized in that: In step S3, the maximum time t from LF leaving the station to continuous casting pouring is calculated. ccm The methods include: According to the historical big data analysis, the transfer time t from LF to the corresponding continuous casting 转运 , if the remaining pouring time of ladle continuous casting is t 连铸剩余 >t 转运 , then t ccm =t 连铸剩余 .

5. The method for predicting LF target temperature and dynamically calculating power-on duration of a ladle furnace according to claim 4, characterized in that: In step S4, it is necessary to wait for the rhythm time t 等待 =t 连铸剩余 -t 转运 .

6. The method for predicting LF target temperature and dynamically calculating power-on time of a ladle furnace according to claim 5, characterized in that: In step S5, the maximum smelting time t LF最大冶炼 =t ccm .

7. The method for predicting LF target temperature and dynamically calculating power-on duration of a ladle furnace according to claim 6, characterized in that: In step S6, the method for real-time prediction of the LF target temperature includes: Through machine learning of a large amount of historical data, it is found that the temperature drop from LF leaving the station to continuous casting pouring is y LF-CMM转运温降 , and then dynamically calculate the LF target temperature T in real time LF目标温度 , the formula is as follows: T LF目标温度＝ T 开浇温度+ t ccm y LF-CMM转运温降 。 8. The method for predicting LF target temperature and dynamically calculating power-on duration of a ladle furnace according to claim 7, characterized in that: In step S7, each time the temperature is measured, the time from the current temperature measurement to the time of leaving the station is triggered to dynamically calculate tcurrent temperature measurement to leaving the station. First, the smelting time tentrance to temperature measurement time during the temperature measurement is calculated by subtracting the temperature measurement time from the current time. The formula is as follows: t 当前测温到离站 =t LF最大冶炼 -t 进站到测温时刻 。 9. The method for predicting LF target temperature and dynamically calculating power-on duration of a ladle furnace according to claim 8, characterized in that: In step S8, each time the temperature is measured, the temperature T required to be raised for electrode heating is triggered to be dynamically calculated. 电极要升温的温度 , get the current temperature T 当前温度 , and after collecting a large amount of historical data, the average natural temperature drop of the smelting process can be obtained through machine learning parameters 平均自然温降 ; The temperature rise required for electrode heating is calculated by the following formula: T 电极要升温的温度 =T LF目标温度 -T 当前温度 +t 当前测温到离站 *y 平均自然温降 。 10. The method for predicting LF target temperature and dynamically calculating power-on time of a ladle furnace according to claim 9, characterized in that: In step S9, the power-on time t of the electrode heating is calculated by the following formula: t=(T 液相温度 +T 过热度 +t 连铸剩余 y 大包-中包温降 +t ccm y LF-CMM转运温降 -T 当前温度 +t 当前测温到离站 *y 平均自然温降 ) / D 电机升温效率 Among them, D 电机升温效率 Electrode heating efficiency for each electrification strategy.

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