Method for triggering a slab heat command in a hot rolling production line

Abstract

A method for triggering a steel demand instruction in a medium-thick plate hot rolling production line includes the following steps: a. Testing the roughing and finishing rolling time of the steel billet, as well as the tapping time and pre-roughing conveying time of each furnace; b. Setting a steel demand timer; c. Selecting the furnace to be tapped and the subsequent tapping furnace; d. Calculating the steel demand time; e. Inputting a steel demand instruction trigger signal, starting the tapping machine of the furnace to be tapped, and setting the timing of the steel demand timer to a specific value; f. After the steel billet is transported, starting the steel demand timer, using the original subsequent tapping furnace as the furnace to be tapped, and selecting a new subsequent tapping furnace; g. Recalculating the steel demand time; h. After the timing expires, starting the tapping machine of the furnace to be tapped, and setting the timing of the steel demand timer to a specific value; i. Repeating steps f to h until the steel billet rolling task is completed. This invention achieves precise matching between the tapping rhythm of the heating furnace and the continuous rolling rhythm of the rolling mill, improving the rolling quality of medium-thick plates.

Description

Technical Field

[0001] This invention relates to a method for triggering steel demand instructions in a medium-thick plate hot rolling production line, which can achieve precise matching between the steel output rhythm of the heating furnace and the continuous rolling rhythm of the rolling mill, and belongs to the field of metal rolling technology. Background Technology

[0002] The main equipment for hot rolling production of medium and heavy plates includes a heating furnace, tapping machine, furnace front roller table, roughing mill roller table, roughing mill, finishing mill roller table, finishing mill, high-pressure water descaling box, and control system. For details, please refer to [link to relevant documentation]. Figure 1 Multiple heating furnaces are arranged along the side of the furnace front roller conveyor, sequentially following the billet conveying direction. Each heating furnace is equipped with at least one set of furnace channels (furnace bottom walking channels) to transport the heated billets to the furnace outlet. Each furnace channel is equipped with a corresponding tapping machine to lift the billets transported from that channel to the furnace outlet and place them onto the furnace front roller conveyor for tapping. The beginning of the roughing mill roller conveyor is connected to the end of the furnace front roller conveyor, and the end of the roughing mill roller conveyor is connected to the inlet of the roughing mill. The beginning of the finishing mill roller conveyor is connected to the outlet of the roughing mill, and the end of the finishing mill roller conveyor is connected to the inlet of the finishing mill. After the control system issues a steel demand command for a specific furnace channel, the corresponding tapping machine first completes the tapping action, transporting the billets to the furnace front roller conveyor, and then sending them to the inlet of the roughing mill via the furnace front roller conveyor and the roughing mill roller conveyor. After the billets complete the set number of reciprocating rolling passes in the roughing mill, they are transported to the finishing mill roller conveyor, and finally sent to the finishing mill by the finishing mill roller conveyor to complete the finishing rolling process. The high-pressure water descaling box is installed above the beginning of the roughing mill roll table and is used to remove iron oxide scale from the surface of the steel billet.

[0003] In the existing non-warm-up plate production mode, the billet does not need to wait for warming after being conveyed to the finishing mill roller table. If the number of finishing passes is the same as the number of roughing passes, for example, when rolling a 15mm thick steel plate, both roughing and finishing require 7 passes. Since the length of the finishing billet is greater than that of the roughing billet, the finishing time is longer than the roughing time, and the continuous rolling rhythm of the mill is mainly determined by the finishing time. If the number of finishing passes is less than the number of roughing passes, for example, 7 roughing passes and 5 finishing passes, then the finishing time is less than the roughing time, and the continuous rolling rhythm of the mill is mainly determined by the roughing time. Currently, in the hot rolling production of medium and heavy plates, operators or control systems mainly trigger steel demand commands based on the current number of passes being rolled on the roughing mill. For example, a steel demand command is triggered when the billet is in the second pass of the roughing mill. In actual production operations, on the one hand, the number of roughing passes manually set by different operators are inconsistent, and the steel demand triggering conditions are inconsistent. On the other hand, the roughing rolling control system can only trigger the steel demand command at the beginning of a certain rolling pass, and cannot trigger the steel demand command at other times of the same rolling pass, resulting in the inability to achieve precise control of the steel demand time. In addition, the tapping time of different tapping machines varies, and the conveying distance and conveying time from each furnace to the roughing roll table (or roughing mill) also vary. The existence of the above reasons means that when most of the billets arrive at the entrance of the roughing mill, they can only stay at the entrance of the roughing mill for a long time to wait for the previous billet to finish roughing, resulting in heat loss and a drop in billet temperature, which directly affects the quality of the finished product. There is also the possibility of untimely steel demand, that is, the previous billet has finished roughing rolling, but the subsequent billet has not yet arrived at the entrance of the roughing mill, resulting in the roughing mill having no steel to roll and having to wait for the billet to be transported, which seriously affects the rolling efficiency of the mill.

[0004] In summary, the existing steel-requiring methods for medium and heavy plate hot rolling production lines suffer from problems such as the inability to precisely match the steel output rhythm of the heating furnace with the continuous rolling rhythm of the rolling mill, and the lack of smooth process connection. These issues seriously affect the continuous operation level and overall production efficiency of medium and heavy plate production lines, and reduce product quality. Summary of the Invention

[0005] The purpose of this invention is to address the shortcomings of existing technologies by providing a method for triggering steel demand instructions in a medium-thick plate hot rolling production line, so as to achieve precise matching between the steel output rhythm of the heating furnace and the continuous rolling rhythm of the rolling mill, thereby improving the rolling quality and rolling efficiency of medium-thick plates.

[0006] The problem described in this invention is solved by the following technical solution: A method for triggering a steel demand order in a medium-thick plate hot rolling production line, the method comprising the following steps: a. Test the roughing rolling time, finishing rolling time, tapping time corresponding to each furnace pass, and pre-roughing conveying time of the steel billet. Roughing rolling time refers to the time it takes for the steel billet to complete a set number of reciprocating rolling passes within the roughing mill; finishing rolling time refers to the time it takes for the steel billet to complete a set number of reciprocating rolling passes within the finishing mill; tapping time refers to the time it takes for the steel billet exiting the heating furnace to be transferred from the tapping machine to the furnace front roller conveyor; and pre-roughing conveying time refers to the time it takes for the steel billet placed on the furnace front roller conveyor to be conveyed along the furnace front roller conveyor and the roughing mill roller conveyor to the entrance position of the roughing mill. b. Set a requisition timer in the control system to trigger requisition commands; c. Select the furnace channel to be tapped and the subsequent tapping furnace channel that is adjacent to it in the tapping sequence; d. Calculate the steel demand time : If the finishing rolling time is longer than the rough rolling time, then ; If the finishing rolling time is less than the roughing rolling time, then ; in, For the finishing rolling time of the steel billet, For the rough rolling time of the steel billet, This refers to the pre-roughing conveying time corresponding to the steel tapping furnace passage. This refers to the tapping time corresponding to the subsequent tapping furnace passage. This refers to the pre-roughing conveying time corresponding to the subsequent furnace passage; e. The operator manually inputs the steel demand command trigger signal, and the control system starts the tapping machine corresponding to the steel tapping channel, transferring the steel billet to be tapped from the steel tapping channel to the front roller conveyor. At the same time, the timing of the steel demand timer is set to... ; f. After the tapping machine corresponding to the tapping furnace channel completes the billet transport operation, the control system starts the steel demand timer, and at the same time, the original subsequent tapping furnace channel is used as the tapping furnace channel, and another furnace channel is selected as the subsequent tapping furnace channel of the tapping furnace channel. g. Recalculate the steel demand time according to the method in step d. ; h. After the steel demand timer finishes its countdown, it outputs a steel demand command trigger signal. Upon receiving this signal, the control system starts the tapping machine corresponding to the steel tapping channel, transferring the steel billet to be tapped from the steel tapping channel to the furnace front roller conveyor. Simultaneously, the countdown timer is set to [time value missing]. ; i. Repeat steps f to h until the billet rolling task is completed.

[0007] The above-mentioned method for triggering steel demand instructions in the medium and heavy plate hot rolling production line involves the following steps: After the billet is transported to the furnace front roller conveyor by the tapping machine, it becomes a tapped billet. If the roughing time of the preceding billet is extended for any reason, and the finishing rolling time is shorter than the roughing rolling time, the tapped billet will wait for warming at the roughing mill. To prevent the next billet from continuing to wait for warming at the roughing mill inlet, the current timing of the steel demand timer needs to be corrected. The corrected timing time... for: ; in, This is an estimated value of the waiting time for the billet to be heated before the roughing mill.

[0008] The method for triggering the steel demand order of the above-mentioned medium and heavy plate hot rolling production line, and the method for estimating the waiting time of the billets before the roughing mill, are as follows: The position of the billet after exiting the hot rolling production line is monitored in real time by a micro-tracking control system. When the front end of the billet reaches the descaling box, the roughing rolling control system of the hot rolling production line reads the rolling pass of the previous billet in the roughing mill. The estimated time for the billet to wait for heating before the roughing mill is: ; in, This refers to the total number of passes in the roughing rolling process. The average time for a single pass in a roughing mill. This refers to the time it takes for the steel billet to be transported from the descaling box to the preheating area before the roughing mill.

[0009] The triggering method for the steel demand instruction of the above-mentioned medium and heavy plate hot rolling production line, wherein the testing method for the roughing rolling time, finishing rolling time, tapping time and pre-roughing rolling conveying time is as follows: the roughing rolling time, finishing rolling time, tapping time and pre-roughing rolling conveying time of the steel billet are measured in different production shifts to obtain a dataset of roughing rolling time measurement values, a dataset of finishing rolling time measurement values, a dataset of tapping time measurement values ​​corresponding to each furnace, and a dataset of pre-roughing rolling conveying time measurement values. The normal distribution average of all data in each dataset is calculated to obtain the required roughing rolling time, finishing rolling time and tapping time and pre-roughing rolling conveying time corresponding to each furnace.

[0010] The triggering method for the steel demand instruction of the above-mentioned medium and heavy plate hot rolling production line is as follows: the steel output sequence of multiple furnace channels is set as follows: if all heating furnaces are intact, the multiple furnace channels will output steel in sequence according to their arrangement; when some heating furnaces cannot operate normally, the furnace channels of the remaining heating furnaces will output steel in sequence according to their arrangement.

[0011] This invention determines the timing of sending steel demand instructions based on the roughing and finishing rolling times of the steel billet, as well as the corresponding tapping time and pre-roughing conveying time of each furnace passage. This achieves precise matching between the steel tapping rhythm of the heating furnace and the continuous rolling rhythm of the rolling mill, avoiding heat loss caused by the steel billet waiting for a long time at the entrance of the roughing mill, thereby improving the rolling quality of medium and heavy plates. Attached Figure Description

[0012] The invention will now be described in further detail with reference to the accompanying drawings.

[0013] Figure 1 This is a schematic diagram of the structure of medium and heavy plate hot rolling production equipment; Figure 2 This is a flowchart of the present invention.

[0014] The labels in the diagram are as follows: 1. First heating furnace, 2. Second heating furnace, 3. Third heating furnace, 4. Steel billet to be tapped, 5. Steel billet tapped, 6. High-pressure water descaling box, 7. Roughing mill roller table, 8. Roughing mill, 9. Finishing mill roller table, 10. Finishing mill, 11. Tapping machine, 12. Furnace front roller table, G1. First furnace table, G2. Second furnace table, G3. Third furnace table, G4. Fourth furnace table, G5. Fifth furnace table, G6. Sixth furnace table.

[0015] Symbols used in the text: In order to save time, For the finishing rolling time of the steel billet, For the rough rolling time of the steel billet, This refers to the pre-roughing conveying time corresponding to the steel tapping furnace passage. This refers to the tapping time corresponding to the subsequent tapping furnace passage. This refers to the conveying time before roughing in the subsequent furnace passage. This is the corrected timing. This is an estimated value of the waiting time for the billet to reach the temperature before the roughing mill. This refers to the total number of passes in the roughing rolling process. The average time for a single pass in a roughing mill. This refers to the time it takes for the steel billet to be transported from the descaling box to the preheating area before the roughing mill. Detailed Implementation

[0016] To address the shortcomings of existing technologies, this invention provides a method for triggering steel demand instructions in a medium-thick plate hot rolling production line. This method achieves seamless coupling between steel output and rolling rhythm, meaning that when the tail of the previous steel plate leaves the rolling mill, the head of the next billet just arrives at the rolling mill inlet, achieving "zero waiting time" and making the entire material flow smooth and continuous. This is a hallmark of achieving high-efficiency and low-energy-consumption production.

[0017] This method includes the following steps: a. Test the roughing rolling time, finishing rolling time, tapping time, and pre-roughing conveying time corresponding to each furnace passage. Roughing rolling time refers to the time it takes for the billet to complete a set number of reciprocating rolling passes within the roughing mill; finishing rolling time refers to the time it takes for the billet to complete a set number of reciprocating rolling passes within the finishing mill; tapping time refers to the time it takes for the billet to be transferred from the furnace outlet to the furnace front conveyor; pre-roughing conveying time refers to the time it takes for the billet placed on the furnace front conveyor to be conveyed along the furnace front conveyor and roughing mill rollers to the entrance of the roughing mill. The tapping time and pre-roughing conveying time are different for different furnace passages. The testing method for roughing rolling time, finishing rolling time, tapping time, and pre-roughing rolling conveying time is as follows: The roughing rolling time, finishing rolling time, tapping time, and pre-roughing rolling conveying time of the billet are measured in different production shifts. Data sets of roughing rolling time measurements, finishing rolling time measurements, tapping time measurements corresponding to each furnace run, and pre-roughing rolling conveying time measurements are obtained. The normal distribution average of all data in each dataset is calculated to obtain the required roughing rolling time, finishing rolling time, tapping time, and pre-roughing rolling conveying time corresponding to each furnace run. The obtained roughing rolling time, finishing rolling time, tapping time, and pre-roughing rolling conveying time are stored in memory for recall by the control system.

[0018] b. Set a steel demand timer in the control system to trigger the steel demand command. The control system can set the timing time of the steel demand timer, start the steel demand timer, and output a steel demand command trigger signal when the steel demand timer ends to start the corresponding steel tapping machine. The timing unit of the steel demand timer is seconds. Steps a and b are the preparatory work before starting up the medium and heavy plate hot rolling production line.

[0019] c. Select the furnace channel to be tapped and the subsequent tapping furnace channel adjacent to it in the tapping sequence: Because there are multiple heating furnaces and multiple furnace runs, and the tapping time and pre-roughing conveying time differ for different furnace runs, the tapping sequence must be determined in advance to accurately calculate the steel demand time. Generally, if all heating furnaces are intact, the multiple furnace runs tap steel sequentially in the order they are arranged. For example, in... Figure 1 In the hot rolling mill equipment for medium and heavy plates shown, if all heating furnaces are intact, the steel tapping sequence of multiple furnace runs can be set as: first furnace run G1, second furnace run G2, third furnace run G3, fourth furnace run G4, fifth furnace run G5, sixth furnace run G6, first furnace run G1, ..., that is, steel is tapped sequentially from first furnace run G1 to sixth furnace run G6. Of course, other sequences are also possible. When some heating furnaces cannot operate normally (e.g., due to maintenance), the remaining furnace runs tap steel sequentially according to their arrangement. For example, in... Figure 1In the medium-thick plate hot rolling production equipment shown, if the second heating furnace 2 cannot operate normally due to a malfunction, and the third furnace channel G3 and the fourth furnace channel G4 cannot tap steel, while the other heating furnaces are intact, the steel tapping sequence of the multiple furnace channels can be set as: first furnace channel G1, second furnace channel G2, fifth furnace channel G5, sixth furnace channel G6, first furnace channel G1, ..., that is, except for the third furnace channel G3 and the fourth furnace channel G4, the other furnace channels tap steel in sequence.

[0020] d. Calculate the steel demand time : If the finishing rolling time is longer than the rough rolling time, then ; If the finishing rolling time is less than the roughing rolling time, then ; in, For the finishing rolling time of the steel billet, For the rough rolling time of the steel billet, This refers to the pre-roughing conveying time corresponding to the steel tapping furnace passage. This refers to the tapping time corresponding to the subsequent tapping furnace passage. This refers to the pre-roughing conveying time corresponding to the subsequent furnace passage; e. The operator manually inputs the steel demand command trigger signal, and the control system starts the tapping machine corresponding to the steel tapping channel, transferring the steel billet to be tapped from the steel tapping channel to the front roller conveyor. At the same time, the timing of the steel demand timer is set to... The first steel demand command trigger signal is manually input by the operator, and subsequent steel demand command trigger signals are automatically output by the steel demand timer; f. After the tapping machine corresponding to the tapping furnace channel completes the billet transport operation, the control system starts the steel demand timer, and at the same time, the original subsequent tapping furnace channel is designated as the tapping furnace channel, and another furnace channel is selected as the subsequent tapping furnace channel of the tapping furnace channel.

[0021] After the tapping machine corresponding to the tapping furnace channel completes the billet handling operation, the tapping sequence of the tapping machine and the lower limit switch signal of the tapping machine are used to determine whether the billet has been tapped and whether the billet has been placed on the front roller conveyor. Once it is detected that the billet has been placed on the front roller conveyor, the billet timer is started immediately. g. Recalculate the steel demand time according to the method in step d. ; h. After the steel demand timer finishes its countdown, it outputs a steel demand command trigger signal. Upon receiving this signal, the control system starts the tapping machine corresponding to the steel tapping channel, transferring the steel billet to be tapped from the steel tapping channel to the furnace front roller conveyor. Simultaneously, the countdown timer is set to [time value missing]. ; i. Repeat steps f to h until the billet rolling task is completed.

[0022] When issuing a steel demand order according to this method, the head of the subsequent steel billet arrives at the entrance of the roughing mill just as the tail of the rolled steel billet leaves the roughing mill, achieving "zero waiting time". After leaving the roughing mill, the steel billet is fed into the finishing mill through the finishing mill roller table to complete the finishing rolling process.

[0023] When the total number of finishing rolling passes equals the total number of roughing rolling passes, the finishing rolling time for the same non-warming plate is greater than the roughing rolling time, and the continuous rolling rhythm of the mill is mainly determined by the finishing rolling time. This represents the conveying time of the steel billet on the finishing mill roller table, that is, the time it takes for the steel billet to be conveyed from the roughing mill exit through the finishing mill roller table into the finishing mill. Therefore, the total time for the steel billet to complete conveying via the furnace front roller table and roughing mill roller table, roughing mill rolling, finishing mill roller table conveying, and finishing mill rolling after exiting the steel mill, without waiting for it to heat up, is: The total time for the billets in the subsequent tapping furnace to complete tapping, conveying on the furnace front roller table and roughing mill roller table, rolling on the roughing mill, and conveying on the finishing mill roller table without waiting for them to reach a certain temperature is: To achieve continuous rolling in the finishing mill without waiting for the temperature to rise during the entire rolling process, the waiting time for billets to tap from the subsequent tapping furnace after the billet tapping should be: Therefore, when the finishing rolling time is longer than the roughing rolling time, the present invention will reduce the steel rolling time. Set to: This allows for precise matching of the steel tapping rhythm from the heating furnace with the continuous rolling rhythm of the rolling mill. In this production mode, the finishing mill rolls continuously, while the roughing mill rolls intermittently, with the interval equal to the difference between the finishing and roughing rolling times. Throughout the entire rolling process, the steel billet does not require heating on either the roughing or finishing mill runners.

[0024] Similarly, when the total number of finishing passes is less than the total number of roughing passes, the finishing time for the same non-warming plate is less than the roughing time, and the continuous rolling rhythm of the mill is mainly determined by the roughing time. After the billet exits the mill, the total time for conveying the billet via the furnace front roller table and the roughing roller table, and for the roughing mill to roll the billet without waiting for it to warm up, is... The total time for billet conveying from the subsequent tapping furnace channel to the furnace front roller conveyor and roughing mill roller conveyor is: To achieve continuous rolling in the roughing mill without waiting for the temperature to rise during the entire rolling process, the waiting time for billets to tap from the subsequent tapping furnace after the billets have been tapped should be: Therefore, when the finishing rolling time is less than the roughing rolling time, the present invention will reduce the steel rolling time. Set to: This allows for precise matching of the steel tapping rhythm from the heating furnace with the continuous rolling rhythm of the rolling mill. In this production mode, the roughing mill rolls continuously, while the finishing mill rolls intermittently, with the interval time equal to the difference between the roughing and finishing rolling times. Throughout the entire rolling process, the steel billet does not require heating on either the roughing or finishing mill runners.

[0025] The following section uses our factory's 2100mm wide steel billet as an example to explain in detail the triggering method of steel demand instructions for the medium and heavy plate hot rolling production line.

[0026] like Figure 1 As shown, three heating furnaces (first heating furnace 1 to third heating furnace 3) are arranged on the side of the front roller conveyor and are arranged sequentially along the billet conveying direction of the front roller conveyor. Each heating furnace is equipped with two sets of furnace channels, for a total of six sets of furnace channels (first furnace channel G1 to sixth furnace channel G6).

[0027] The first step was to test the roughing time of a 2100mm wide steel billet, as well as the tapping time and pre-roughing conveying time corresponding to each furnace passage.

[0028] In different production shifts, the roughing rolling time, finishing rolling time, tapping time, and pre-roughing rolling conveying time of 2100mm wide steel billets were measured. Data sets of finishing rolling time measurements, roughing rolling time measurements, tapping time measurements corresponding to each furnace pass, and pre-roughing rolling conveying time measurements were obtained. The normal distribution mean of all data in each dataset was calculated to obtain the required roughing rolling time and the corresponding tapping and pre-roughing rolling conveying times for each furnace pass. The finishing rolling time for a 2100mm wide steel billet is calculated using 5 passes for finishing rolling and 7 passes for rough rolling. The roughing time is 80 seconds. The average time for a single pass of the roughing mill is 14 seconds, which is 98 seconds. The tapping time corresponding to each furnace channel: The tapping time for the first furnace channel G1 is 62 seconds; The tapping time for the second furnace channel G2 is 62 seconds; The tapping time for the third furnace channel G3 is 58 seconds. The tapping time for the fourth furnace channel G4 is 67 seconds; The tapping time for the fifth furnace channel G5 is 56 seconds; The tapping time for the sixth furnace, G6, is 52 seconds. Pre-rolling conveying time corresponding to each furnace passage: The conveying time before roughing rolling corresponding to the first furnace channel G1 is 15 seconds; The conveying time before roughing rolling corresponding to the second furnace channel G2 is 18 seconds; The conveying time before roughing rolling corresponding to the third furnace channel G3 is 28 seconds; The conveying time before roughing milling corresponding to the fourth furnace channel G4 is 31 seconds; The conveying time before roughing milling corresponding to the fifth furnace channel G5 is 42 seconds; The conveying time before roughing milling corresponding to the sixth furnace channel G6 is 44 seconds; The second step is to set the steel timer in the control system, and set the timing unit of the steel timer to seconds; Step 3: Select the furnace channel to be tapped and the subsequent furnace channel adjacent to it in the tapping sequence: Because the third heating furnace 3 is out of service for maintenance, only the first heating furnace 1 and the second heating furnace 2 are used to heat the steel billets. The steel tapping sequence of the four furnace channels is: first furnace channel G1, second furnace channel G2, third furnace channel G3, fourth furnace channel G4, first furnace channel G1, ..., that is, steel is tapped in a cyclical manner from first furnace channel G1 to fourth furnace channel G4. The steel billet tapping sequence is: first furnace channel billet, second furnace channel billet, third furnace channel billet, fourth furnace channel billet, first furnace channel billet, ...

[0029] Therefore, in the first control cycle, the first furnace channel G1 is selected as the furnace channel to be tapped, and the second furnace channel G2 is selected as the subsequent tapping furnace channel. At this time, =98 seconds, =15 seconds, =62 seconds, =18 seconds.

[0030] Step 4: Calculate the steel demand time:

[0031] Step 5: The operator manually inputs the steel demand command trigger signal, and the control system starts the tapping machine corresponding to the steel tapping channel (i.e., the first channel G1), transferring the steel billets to be tapped from the channel to the front roller conveyor. At the same time, the timing of the steel demand timer is set to... =33 seconds; Step 6: After the tapping machine corresponding to the steel billet to be tapped in the first tapping channel (G1) completes the billet transport operation, the control system starts the steel demand timer. Simultaneously, the original subsequent tapping channel, G2 (the second tapping channel), is designated as the next tapping channel, and G3 (the third tapping channel) is selected as the next tapping channel for this channel. =98 seconds, =18 seconds, =58 seconds, =28 seconds. After the steel billet from the first furnace pass G1 falls onto the furnace front roller conveyor, it is transported from the furnace front roller conveyor to the roughing roller conveyor, and then from the roughing roller conveyor to the roughing mill for roughing.

[0032] Step 7: Recalculate the steel demand time. :

[0033] Step 8: After the steel demand timer finishes timing, it outputs a steel demand command trigger signal. Upon receiving this signal, the control system starts the steel tapping machine corresponding to the second steel tapping channel G2, transferring the steel billets to be tapped from the second steel tapping channel G2 to the front roller conveyor. At the same time, the timing of the steel demand timer is set to... =30 seconds; Step 9: After the tapping machine corresponding to the steel billet to be tapped in the steel tapping channel (i.e., the second channel G2) completes the billet transport operation, the control system starts the steel demand timer. The steel demand timer begins timing, and at the same time, the original subsequent tapping channel, i.e., the third channel G3, is designated as the steel tapping channel, and the fourth channel G4 is selected as the subsequent tapping channel for this steel tapping channel. At this time, =98 seconds, =28 seconds, =67 seconds, =31 seconds.

[0034] Step 10: Recalculate the steel demand time. :

[0035] Step 11: After the steel demand timer finishes timing, it outputs a steel demand command trigger signal. Upon receiving this signal, the control system starts the steel tapping machine corresponding to the third furnace channel G3, transferring the steel billet to be tapped from the third furnace channel G3 to the front roller conveyor. At the same time, the timing of the steel demand timer is set to... =28 seconds; Step 12: After the tapping machine corresponding to the steel billet to be tapped in the steel tapping channel (i.e., the third channel G3) completes the billet transport operation, the control system starts the steel demand timer. Simultaneously, the original subsequent tapping channel, i.e., the fourth channel G4, is designated as the steel tapping channel, and the first channel G1 is selected as the subsequent tapping channel for this steel tapping channel. At this time... =98 seconds, =31 seconds, =62 seconds, =15 seconds.

[0036] Step 13: Recalculate the steel demand time. :

[0037] Step 14: After the steel demand timer finishes timing, it outputs a steel demand command trigger signal. Upon receiving this signal, the control system starts the tapping machine corresponding to the fourth furnace channel G4, transferring the steel billet to be tapped from G4 to the furnace front roller conveyor. Simultaneously, the timing of the steel demand timer is set to... =52 seconds; Step 15: After the tapping machine corresponding to the steel billet to be tapped in the fourth tapping furnace (G4) completes the billet transport operation, the control system starts the steel demand timer. Simultaneously, the original subsequent tapping furnace, namely the first tapping furnace (G1), is designated as the next tapping furnace, and the second tapping furnace (G2) is selected as the next tapping furnace. At this time... =98 seconds, =15 seconds, =62 seconds, =18 seconds.

[0038] Step 16: Recalculate the steel demand time. :

[0039] Step 17: After the steel demand timer finishes timing, it outputs a steel demand command trigger signal. Upon receiving this signal, the control system starts the steel tapping machine corresponding to the first steel tapping channel G1, transferring the steel billet to be tapped from the first steel tapping channel G1 to the front roller conveyor. At the same time, the timing of the steel demand timer is set to... =33 seconds; Step 18: After the tapping machine corresponding to the steel billet to be tapped in the first tapping channel (G1) completes the billet transport operation, the control system starts the steel demand timer. Simultaneously, the original subsequent tapping channel, G2 (the second tapping channel), is designated as the next tapping channel, and G3 (the third tapping channel) is selected as the next tapping channel for this channel. =98 seconds, =18 seconds, =58 seconds, =28 seconds.

[0040] This process is repeated until the billet rolling task is completed.

[0041] After the billet is transported to the furnace front roller conveyor by the tapping machine, it becomes a tapped billet. Under normal circumstances, when this tapped billet reaches the entrance of the roughing mill, the previous billet has just completed its roughing rolling. If the finishing rolling time is shorter than the roughing rolling time, and if the previous billet experienced issues such as poor steel transfer or iron bridging during roughing rolling, causing its roughing rolling time to be extended, then this tapped billet will wait for heating before the roughing mill. To prevent the next billet from also waiting for heating at the roughing mill entrance, the current timing of the billet timer needs to be corrected. The corrected timing time... for:

[0042] in, This is an estimated value of the waiting time for the billet to be heated before the roughing mill.

[0043] Since the roughing of the previous billet has not yet been completed, the waiting time of the billet before the roughing mill is still uncertain. Therefore, only an estimated value can be used to correct the current timing of the billet timer. The method for estimating the waiting time of the billet before the roughing mill is as follows: The position of the billet after exiting the hot rolling production line is monitored in real time by a micro-tracking control system. When the front end of the billet reaches the descaling box, the roughing rolling control system of the hot rolling production line reads the rolling pass of the previous billet in the roughing mill. The estimated time for the billet to wait for heating before the roughing mill is:

[0044] in, This refers to the total number of passes in the roughing rolling process. The average time for a single pass in a roughing mill. This refers to the time it takes for the steel billet to be transported from the descaling box to the preheating area before the roughing mill.

[0045] The roughing rolling control system can detect the number of reciprocating rolling passes of the billet in the roughing mill using a hot metal detector, indicating the current rolling pass of the billet in the roughing mill. This can be calculated using the rolling logic of steel rolling. Each time the hot metal detector detects a steel billet, the rolling pass number is incremented by one. Total number of roughing rolling passes. Provided by the secondary rolling model of the control system, when the hot metal detector... When the billet is detected for the first time, the number of rolling passes of the billet in the roughing mill is [number missing]. The number of passes required for rough rolling is 10. Since the roughing billet is relatively short, the rolling time for each pass is roughly the same. Therefore, the average time for a single pass of the roughing mill is used in the calculation. Because the billet reading from the roughing rolling control system is in the roughing mill during the rolling passes... It can only indicate that the current rolling pass is... However, it cannot be determined whether the current time is the start time, end time, or some time between the start and end times of the nth rolling pass. Therefore, to prevent the next billet from waiting to warm up at the inlet of the roughing mill, it is assumed that the current time is the start time of the nth rolling pass, and the remaining time for the entire roughing process is... This calculation of the remaining time, while potentially extending the heating time of already produced billets, ensures that subsequent billets will not require further heating. Assume a total of [number] passes in the roughing mill. The value is 7, which refers to the number of rolling passes of the previous billet in the roughing mill. =4, the average time for a single pass in the roughing mill is . =14 seconds, the time it takes for the steel billet to be transported from the descaling box to the preheating area in front of the roughing mill was measured on site. =7 seconds, then the estimated time for the billet to wait for warming in front of the roughing mill is:

[0046] After this system is put into use, it will have the following main advantages: 1) Energy conservation and consumption reduction: • The temperature drop is minimal after the slab exits the furnace (due to the extremely short waiting time).

[0047] • Hot loading and hot delivery maximize the effect and significantly reduce gas consumption.

[0048] • Reducing the waiting time lowers the energy consumption of the waiting roller conveyor.

[0049] 2) Improve quality and stabilize production: • Stable rolling temperature results in high product quality consistency.

[0050] • Reduces fluctuations in production rhythm, stabilizes equipment load, and lowers failure rate.

[0051] 3) Maximize capacity: Achieve the highest effective operating rate (rolling mill utilization).

Claims

1. A method of triggering of steel orders for a medium plate hot rolling line, characterized in that, The method includes the following steps: a. Test the roughing rolling time, finishing rolling time, tapping time corresponding to each furnace pass, and pre-roughing conveying time of the steel billet. Roughing rolling time refers to the time it takes for the steel billet to complete a set number of reciprocating rolling passes within the roughing mill; finishing rolling time refers to the time it takes for the steel billet to complete a set number of reciprocating rolling passes within the finishing mill; tapping time refers to the time it takes for the steel billet exiting the heating furnace to be transferred from the tapping machine to the furnace front roller conveyor; and pre-roughing conveying time refers to the time it takes for the steel billet placed on the furnace front roller conveyor to be conveyed along the furnace front roller conveyor and the roughing mill roller conveyor to the entrance position of the roughing mill. b. Set a requisition timer in the control system to trigger requisition commands; c. Select the furnace channel to be tapped and the subsequent tapping furnace channel that is adjacent to it in the tapping sequence; d. Calculate the time to steel : If the finish rolling time is greater than the rough rolling time, then ; If the finish rolling time is less than the rough rolling time, then ; in, For the finishing rolling time of the steel billet, For the rough rolling time of the steel billet, This refers to the pre-roughing conveying time corresponding to the steel tapping furnace passage. This refers to the tapping time corresponding to the subsequent tapping furnace passage. This refers to the pre-roughing conveying time corresponding to the subsequent furnace passage; e.The operator manually inputs the steel tapping instruction trigger signal, and the control system starts the tapping machine corresponding to the tapping furnace channel to be tapped, and carries the tapping billet on the tapping furnace channel to be tapped to the furnace front roller way, and sets the timing time of the steel tapping timer to ; f. After the tapping machine corresponding to the tapping furnace channel completes the billet transport operation, the control system starts the steel demand timer, and at the same time, the original subsequent tapping furnace channel is used as the tapping furnace channel, and another furnace channel is selected as the subsequent tapping furnace channel of the tapping furnace channel. g. Recalculate lead time for steel as per step d ; h.the output of the steel command trigger signal after the steel timer ends, and the control system receives the signal to start the tundish corresponding to the tundish on the tundish, and the tundish on the tundish is transported to the roller way, and the timing of the steel timer is set to ; i. Repeat steps f to h until the billet rolling task is completed.

2. The method for triggering a steel demand instruction in a medium-thick plate hot rolling production line according to claim 1, characterized in that, after the billet to be tapped is transported to the furnace front roller conveyor by the tapping machine, it becomes a tapped billet. If the roughing time of the preceding billet is extended for any reason when the finishing rolling time is less than the roughing rolling time, the tapped billet will wait for heating in front of the roughing mill. To prevent the next billet from continuing to wait for heating at the roughing mill inlet, the current timing of the steel demand timer needs to be corrected. The corrected timing time... for: ； in, This is an estimated value of the waiting time for the billet to be heated before the roughing mill.

3. The method for triggering a steel demand instruction in a medium-thick plate hot rolling production line according to claim 2, characterized in that, The method for estimating the waiting time of the billet before the roughing mill is as follows: The position of the billet after exiting the hot rolling production line is monitored in real time by a micro-tracking control system. When the front end of the billet reaches the descaling box, the roughing rolling control system of the hot rolling production line reads the rolling pass of the previous billet in the roughing mill. The estimated time for the billet to wait for heating before the roughing mill is: ； in, This refers to the total number of passes in the roughing rolling process. The average time for a single pass in a roughing mill. This refers to the time it takes for the steel billet to be transported from the descaling box to the preheating area before the roughing mill.

4. A method for triggering a steel demand instruction for a medium-thick plate hot rolling production line according to any one of claims 1-3, characterized in that, The testing method for roughing rolling time, finishing rolling time, tapping time, and pre-roughing conveying time is as follows: The roughing rolling time, finishing rolling time, tapping time, and pre-roughing conveying time of the billet are measured in different production shifts to obtain datasets of roughing rolling time measurements, finishing rolling time measurements, tapping time measurements corresponding to each furnace, and pre-roughing conveying time measurements. The normal distribution average of all data in each dataset is calculated to obtain the required roughing rolling time, finishing rolling time, tapping time corresponding to each furnace, and pre-roughing conveying time.

5. The method for triggering a steel demand instruction in a medium-thick plate hot rolling production line according to claim 4, characterized in that, The steel tapping sequence of multiple furnace channels is set as follows: if all heating furnaces are intact, the multiple furnace channels will tap steel in sequence according to their arrangement; when some heating furnaces cannot operate normally, the furnace channels of the remaining heating furnaces will tap steel in sequence according to their arrangement.

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