Automatic tapping control method based on rolling rhythm

Abstract

The invention relates to an automatic tapping control method based on a rolling rhythm. The automatic tapping control method comprises the steps of tapping rhythm intelligence, accurate digital control, safety linkage protection and the like. According to different thickness specifications, the tapping interval time of the online input heating furnace is automatically calculated, automatic tapping is achieved, manual intervention is not needed, the production rhythm is more accurately controlled on site, production is more efficiently organized, the higher hourly steel yield is achieved, and therefore energy consumption is reduced; the stacking accident of two front and back coils of steel caused by too fast rhythm is avoided; the labor intensity of operators is reduced, and post requirements are reduced; the product quality tends to be stable, and the quality index hit rate is stably improved.

Description

Technical Field

[0001] The present invention relates to the technical field of intelligent and digital control of hot-rolled strip, and particularly relates to an automatic steel discharging control method based on rolling rhythm. Background Art

[0002] At present, the automation control of hot-rolled production lines put into production before 2007 has fallen seriously behind. Especially in the control of steel discharging rhythm, it is impossible to keep four slabs online for a long time, and various factors restrict the production capacity of hot-rolled strip production lines. Compared with steel enterprises with a relatively high degree of automation of the same kind, the hourly steel output is about 10% lower, and there is a big gap in energy consumption, production capacity utilization rate, etc., and there is a serious lack of competitiveness. Each time a slab is discharged from the reheating furnace, it is completed by the operator's manual jogging. The rhythm is initiated by oral communication between the upstream and downstream processes. The communication process takes a long time, has poor compactness, and low efficiency. Once the rhythm is too fast, it is easy to wait for steel in front of the rolling mill or stack the heads and tails of the front and rear slabs, resulting in potential production accidents, and it is difficult to manually monitor. Summary of the Invention

[0003] In view of the above problems, the purpose of the present invention is to provide an automatic steel discharging control method based on rolling rhythm, which automatically calculates the steel discharging interval time of the reheating furnace put into operation online according to different thickness specifications, and realizes automatic steel discharging without manual intervention, helps to more accurately control the production rhythm on site, organize production more efficiently, achieve a higher hourly steel output, thereby reducing energy consumption; avoid the accident of superposition of the front and rear coils caused by too fast rhythm; reduce the labor intensity of operators, reduce the number of positions required; the product quality tends to be stable, and the hit rate of quality indicators steadily increases.

[0004] The technical solution adopted by the present invention is as follows:

[0005] An automatic steel discharging control method based on rolling rhythm proposed by the present invention includes the following steps:

[0006] S1. Divide the existing hot-rolled production line into six regions 1-6;

[0007] S2. Define the tracking signal points of the six regions;

[0008] S3. Count the rolling time consumed by strip steel with different thickness specifications in the six regions;

[0009] S4. Establish a six-region production time consumption statistical table for each specification of strip steel, and define the region with the longest time consumption in each specification as the bottleneck point for production rhythm control;

[0010] S5. It is stipulated that when the hot detection signal disappears before the billet runs to the No. 1 reheating furnace, it is considered that the tapping is completed. A sequence control program is established, and the tapping sequence is No. 3, No. 1, and No. 2. After the tapping of a slab A is completed, the countdown for the tapping initiation of the next slab B starts, and so on.

[0011] S6. Collect the set thickness of the finished product of slab B, and the one with the longest time consumption in the six - area production time - consumption statistical table is used as the bottleneck point for production rhythm control.

[0012] S7. Statistically calculate the time interval from the tapping initiation to the tapping completion of each of the three reheating furnaces. Among them, the No. 3 furnace is used as the reference time interval for tapping, marked as "No. 3 furnace reference". The other two furnaces also have interval correction times, which are the corresponding trigger times extended due to the time - consumption difference, marked as "No. 1 furnace correction" and "No. 2 furnace correction".

[0013] S8. If the bottleneck point time exceeds the interval reference time of the No. 3 furnace, the difference between them is used as the "No. 3 furnace reference"; if the bottleneck point time is equal to the interval reference time of the No. 3 furnace, the "No. 3 furnace reference" is zero.

[0014] S9. Final result: The tapping interval time of the No. 1 furnace: After the tapping of the slab in the No. 3 furnace is completed, the countdown starts, and after a period of time of ["No. 3 furnace reference" + "No. 1 furnace correction value"], the tapping is completed; the tapping interval time of the No. 2 furnace: After the tapping of the slab in the No. 1 furnace is completed, the countdown starts, and after a period of time of ["No. 3 furnace reference" + "No. 2 furnace correction value"], the tapping is completed; the tapping interval time of the No. 3 furnace: After the tapping of the slab in the No. 2 furnace is completed, the countdown starts, and after a period of time of "No. 3 furnace reference", the tapping is completed.

[0015] S10. Set up an interlock protection program.

[0016] Furthermore, in the step S1, the principle of area division is that no two billets are allowed to exist simultaneously within each area to avoid the risk of front - back superposition.

[0017] Furthermore, in the step S2, the tracking signal points of the six areas are respectively: Area 1 is from the tapping request of the No. 3 furnace to the tapping completion; Area 2 is from the tapping completion to the biting of the third pass of R1; Area 3 is from the biting of the third pass of R1 to the biting of the third pass of R2; Area 4 is from the biting of the third pass of R2 to the biting of F1; Area 5 is from the biting of F1 to the throwing of steel by F7; Area 6 is from the throwing of steel by F7 to the coiling completion.

[0018] Furthermore, in the step S10, the interlock protection program includes Protection 1: When receiving the biting signal of the third pass of R1, it allows the next slab to enter the descaling box; Protection 2: When receiving the biting signal of the third pass of R2, it allows the next slab to be bitten by the third pass of R1; Protection 3: When receiving the biting signal of F1, it allows the next slab to be bitten by the third pass of R2.

[0019] The present invention has the following beneficial effects compared with the prior art:

[0020] The present invention can effectively increase the hourly steel output of hot rolling; the risk of the head and tail of two consecutive coils overlapping at the rolling head is reduced to zero; the labor intensity of on-site workers is alleviated, and the number of on-site operators is reduced; the steel output rhythm is not manually intervened, eliminating human operation errors, and the production is smoother; the rhythm control is more reasonable, reducing the deviation of the rolling start temperature between strips, and steadily improving the quality precision control. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic diagram of the zoning of the existing hot rolling production process flow according to the present invention;

[0022] Figure 2 It is a schematic diagram of the steel output initiation logic control process according to the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0023] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0024] An automatic steel output control method based on rolling rhythm proposed by the present invention specifically includes the following steps:

[0025] S1. As Figure 1 shown, the existing hot rolling production line is divided into six areas, namely Area 1, Area 2, Area 3, Area 4, Area 5, and Area 6; the principle of area division is that no two pieces of steel are allowed to exist simultaneously within each area to avoid the risk of front-back superposition.

[0026] Among them, the composition of the existing hot rolling production process equipment is: three walking beam reheating furnaces, descaling before rolling, R1 two-high roughing mill, R2 four-high roughing mill, hot coil box, flying shear, finish descaling, F1 - F7 finishing mills, laminar cooling, and coiler; as Figure 1 shown, among them, HF1 - HF3: three reheating furnaces; HSB: roughing descaling; R1D: descaling before R1; R2D: descaling before R2; E1, E2: roughing front vertical rolls; RT: roughing front pyrometer; R1, R2: two roughing mills; CB: hot coil box; CS: flying shear; FET: finishing entrance pyrometer; FSB: finish descaling; F1E: finishing front vertical roll; F1 - F7: seven finishing mills; FDT: finishing exit pyrometer; LCS: laminar cooling mechanism; CT: coiling front pyrometer; DC1 - DC3: three underground coiler take-ups.

[0027] S2. Define the tracking signal points for six areas: Area 1 is from the tapping request of Furnace No. 3 to the completion of tapping; Area 2 is from the completion of tapping to the biting of the third pass of R1; Area 3 is from the biting of the third pass of R1 to the biting of the third pass of R2; Area 4 is from the biting of the third pass of R2 to the biting of F1; Area 5 is from the biting of F1 to the steel throwing of F7; Area 6 is from the steel throwing of F7 to the completion of coiling. Signal tracking is achieved by setting sensors at each tracking signal point.

[0028] S3. According to historical production data, count the rolling time consumed by strip steel of different thickness specifications in the six areas; if necessary, it can be subdivided into steel grades according to the actual situation; considering the actual changes on site, due to equipment reasons or technological updates, the consumption time may increase or decrease, and this data can be updated regularly to establish a self-learning mechanism; it can also be updated manually.

[0029] S4. Establish a six-area production time consumption statistical table for the hot rolling production line of each specification of strip steel, and identify the area with the longest time consumption among each specification as the bottleneck point for production rhythm control.

[0030] S5. It is stipulated that the disappearance of the hot inspection signal in front of the 1# heating furnace when the billet runs is regarded as the completion of tapping. A sequence control program is established, and the tapping sequence is 3#, 1#, 2#; after the tapping of a slab A is completed, a countdown starts for the initiation of the tapping of the next slab B, and so on.

[0031] S6. Collect the set thickness of the finished product of slab B, and the area with the longest time consumption corresponding to the six-area production time consumption statistical table is the bottleneck point for production rhythm control.

[0032] S7. Statistically calculate the time interval from the initiation of tapping to the completion of tapping for each of the three heating furnaces. Among them, Furnace No. 3 is the farthest from the hot inspection signal and has the longest time consumption, which is used as the reference time for the tapping interval and marked as "Furnace No. 3 reference"; the other two furnaces also have interval correction times, which are the corresponding trigger times extended due to the time consumption difference and marked as "Furnace No. 1 correction" and "Furnace No. 2 correction"; this correction value is related to the equipment operation time. Since the operation sequence and actions of the tapping machine are fixed, and the running distance and speed of the billet are also basically fixed, it is a fixed value and has nothing to do with the rhythm change after the rolling line changes specifications.

[0033] S8. If the bottleneck point time exceeds the interval reference time of Furnace No. 3, then the difference between them is used as the "Furnace No. 3 reference"; if the bottleneck point time is equal to the interval reference time of Furnace No. 3, then the "Furnace No. 3 reference" is zero.

[0034] S9. Final result: Tapping interval for Furnace 1: When the tapping of the slab in Furnace 3 is completed, the countdown starts. After ["Benchmark of Furnace 3" + "Correction value of Furnace 1"] time, the tapping is completed; Tapping interval for Furnace 2: When the tapping of the slab in Furnace 1 is completed, the countdown starts. After ["Benchmark of Furnace 3" + "Correction value of Furnace 2"] time, the tapping is completed; Tapping interval for Furnace 3: When the tapping of the slab in Furnace 2 is completed, the countdown starts. After "Benchmark of Furnace 3" time, the tapping is completed.

[0035] S10. Set up an interlock protection program to establish a safety interlock protection between two adjacent slabs through the action permission between sequence control signals.

[0036] The interlock protection program includes Protection 1: When the biting signal of the third pass of R1 is received, the next slab is allowed to enter the descaling box; Protection 2: When the biting signal of the third pass of R2 is received, the next slab is allowed to bite into the third pass of R1; Protection 3: When the biting signal of F1 is received, the next slab is allowed to bite into the third pass of R2.

[0037] The following further illustrates the present invention by substituting specific examples:

[0038] When the tapping of the slab with a thickness specification of 2.5 mm is completed, after comparison, the bottleneck point in the area is 175 seconds in Zone 5. At this time, the tapping time corresponding to Zone 1 is 90 seconds, "Correction of Furnace 1" is 68 seconds (the tapping time of Furnace 1 is 22 seconds); "Correction of Furnace 2" is 42 seconds (the tapping time of Furnace 2 is 48 seconds). At this time, the "Benchmark of Furnace 3" for automatic tapping is 175 - 90 = 85 seconds. If Furnace 1 taps steel, the interval time from the previous "tapping completed" to triggering "tapping initiation" is 85 + 68 = 153 seconds; if Furnace 2 taps steel, the interval time is 85 + 42 = 127 seconds; if Furnace 3 taps steel, the interval time is 85 seconds.

[0039] When the tapping of the slab with a thickness specification of 5.5 mm is completed, after comparison, the bottleneck point in the area is 90 seconds in Zone 1. At this time, the tapping interval time corresponding to Zone 1 is 90 seconds, "Correction of Furnace 1" is 68 seconds; "Correction of Furnace 2" is 42 seconds. At this time, the "Benchmark of Furnace 3" for automatic tapping is 0 seconds. If Furnace 1 taps steel, the countdown is 0 + 68 = 68 seconds; if Furnace 2 taps steel, the countdown is 0 + 42 = 42 seconds; if Furnace 3 taps steel, the countdown is 0 seconds.

[0040] When the tapping of the slab with a thickness specification of 7.5 mm is completed, after comparison, the bottleneck point in the area is 95 seconds in Zone 2. At this time, the tapping interval time corresponding to Zone 1 is 90 seconds, "Correction of Furnace 1" is 68 seconds; "Correction of Furnace 2" is 42 seconds. At this time, the "Benchmark of Furnace 3" for automatic tapping is 95 - 90 = 5 seconds. If Furnace 1 taps steel, the countdown is 5 + 68 = 73 seconds; if Furnace 2 taps steel, the countdown is 5 + 42 = 47 seconds; if Furnace 3 taps steel, the countdown is 5 seconds.

[0041] In the present invention, by setting strip position sensors and collecting the operating parameters of the rolling mill itself in the rolling mill control system, data such as the rolling speed of the rolling mill, the rolling specifications, the travel time of the strip in each area, and the rolling time are obtained. Since the rolling mill speed of strip of each specification is stable and the slab length is fixed, the rolling time is relatively fixed. Based on these data, the system can construct a basic rolling rhythm pattern. This control method also sets up a feedback adjustment mechanism. When it is detected that the rolling rhythm changes, for example, the rolling speed of the previous piece slows down, the system will timely adjust the tapping time and delay the trigger time of the next tapping to avoid excessive temperature reduction of the billet during the waiting process.

[0042] Matters not detailed in the present invention are all well-known technologies.

[0043] The embodiments described above are only used to describe the preferred embodiments of the present invention, and do not limit the scope of the present invention. Without departing from the design spirit of the present invention, various deformations and improvements made by those of ordinary skill in the art to the technical solutions of the present invention shall fall within the protection scope determined by the claims of the present invention.

Claims

1. An automatic steel tapping control method based on rolling rhythm, characterized in that: The following steps are involved: S1. Divide the existing hot rolling production line into six areas 1-6; S2. Identify tracking signal points in six areas; S3, calculating the rolling time consumed by strip steels of different thickness specifications in six areas; S4. Establish a statistical table of production time consumption in six areas of strip steel of each specification, and identify the area with the longest production time in each specification, which will be used as the bottleneck point for production rhythm control; S5. It is stipulated that the steel billet is discharged when the heat detection signal disappears in front of the 1# heating furnace, and a sequential control program is established, with the discharge sequence of 3#, 1#, and 2#. After the discharge of one slab A is completed, the countdown starts, and the discharge of the next slab B is initiated, and so on. S6. Collect the set thickness of the finished product of slab B, and use the longest production time in the statistical table of six-area production time consumption as the bottleneck point for production rhythm control; S7, counting the time interval from the start of steel tapping to the completion of steel tapping for each of the three heating furnaces, where the No. 3 furnace is used as the steel tapping interval benchmark time, marked as "3# furnace benchmark", and the other two furnaces also have interval correction time, and the corresponding trigger time is extended for the time difference, marked as "1# furnace correction" and "2# furnace correction"; S8. If the bottleneck time exceeds the No. 3 furnace interval benchmark time, the difference between them will be used as the "No. 3 furnace benchmark"; If the bottleneck time is equal to the interval benchmark time of furnace No. 3, then the "furnace No. 3 benchmark" is zero; S9, final result: 1# furnace tapping interval time: the countdown starts when the slab tapping in the 3# furnace is completed, and the tapping is completed after the period of ["3# furnace benchmark" + "1# furnace correction value"]; 2# furnace tapping interval time: the countdown starts when the slab tapping in the 1# furnace is completed, and the tapping is completed after the period of ["3# furnace benchmark" + "2# furnace correction value"]; 3# furnace tapping interval time: the countdown starts when the slab tapping in the 2# furnace is completed, and the tapping is completed after the period of "3# furnace benchmark"; S10. Set up a chain protection program.

2. The automatic steel tapping control method based on rolling rhythm according to claim 1, characterized in that: In step S1, the principle of area division is: no two pieces of steel are allowed to exist in each area at the same time to avoid the risk of front and back overlap.

3. The automatic steel tapping control method based on rolling rhythm according to claim 1, characterized in that: In step S2, the tracking signal points of the six areas are: Area 1 is the steel tapping request of No. 3 furnace-steel tapping is completed; Area 2 is steel tapping completion-R1 third pass bite; Area 3 is R1 third pass bite-R2 third pass bite; Area 4 is R2 third pass bite-F1 bite; Area 5 is F1 bite-F7 steel throwing; Area 6 is F7 steel throwing-coiling completion.

4. The automatic steel tapping control method based on rolling rhythm according to claim 1, characterized in that: In step S10, the interlocking protection procedure includes protection 1: upon receiving the bite signal of the third pass of R1, the next slab is allowed to enter the descaling box; protection 2: upon receiving the bite signal of the third pass of R2, the next slab R1 is allowed to bite in the third pass; protection 3: upon receiving the bite signal of F1, the next slab R2 is allowed to bite in the third pass.

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