LF refining furnace charging precision optimization control method and device and storage medium

Abstract

According to the LF refining furnace feeding precision optimization control method and device and the storage medium, a material type compensation coefficient is set, a proportionality coefficient P in PID parameters is multiplied by K and then output, and the large influence of material types on delay is reduced; on the basis of an original PID (Proportion Integration Differentiation) controller, an anti-parallel Smith pre-estimation compensator is added to form a new controller, and control parameters are optimally set according to pre-estimation deviation, so that the feeding precision of the LF furnace is greatly improved.

Description

Technical Field

[0001] The invention relates to the technical field of iron and steel metallurgy, and in particular to a method and system for optimizing control of charging accuracy of an LF refining furnace. Background Art

[0002] LF ladle refining furnace is an important refining equipment, which has been widely used in recent years. In the production process, the feeding system is the main process equipment for controlling the composition of molten steel. Since there is a significant lag between the weighing weight and the feeding action during the entire feeding process, it is easy to cause abnormal deviations between the actual feeding value and the set value. Ordinary PID algorithms are difficult to meet the feeding speed and accuracy required by the process.

[0003] Smith predictive control is a predictive control method proposed by Swedish scientist Smith to solve the time-delay system control problem. It has been widely used in recent years because it can offset the influence of pure hysteresis characteristics, significantly reduce overshoot, accelerate the adjustment process, and improve control quality.

[0004] Refined steel grades have very strict requirements on grade quality. In order to improve the control accuracy of the feeding system, the development of a frequency dynamic control model in the process of variable frequency control weighing and feeding has become an urgent problem to be solved. Summary of the invention

[0005] The purpose of the present invention is to provide a LF refining furnace charging accuracy optimization control method, equipment and storage medium to overcome the abnormal deviation between the set value and the actual value caused by the time lag in the charging process, and improve the charging control accuracy of the LF refining furnace.

[0006] The present invention specifically adopts the following technical solutions:

[0007] According to a first aspect of the present invention, an embodiment of the present invention provides a method for optimizing the charging accuracy of a LF refining furnace, characterized in that it comprises the following steps:

[0008] Set material compensation coefficient according to material characteristics;

[0009] Design the Smith predictor compensator, whose transfer function is:

[0010]

[0011] Z is a discrete complex frequency domain operator, which is obtained by discrete Z domain transformation of the time domain transfer function that varies with time, based on the feedback of the deviation between the set value and the actual value of the feeding system;

[0012] The new controller is formed by connecting the Smith predictive compensator designed in reverse parallel to the original PID controller.

[0013] The proportional coefficient P in the PID parameters of the new controller is multiplied by the corresponding material compensation coefficient to perform material addition control.

[0014] On the other hand, an embodiment of the present invention further provides an electronic device, comprising a processor and a memory, wherein the memory stores a program that can be run on the processor, and is characterized in that when the program is executed by the processor, the steps of the above-mentioned LF refining furnace charging accuracy optimization control method are implemented.

[0015] On the other hand, an embodiment of the present invention further provides a computer-readable storage medium storing at least one program, characterized in that the at least one program can be executed by at least one processor to implement the steps of the above-mentioned LF refining furnace charging accuracy optimization control method.

[0016] The problem of feeding accuracy is a pain point that troubles metallurgical enterprises. The LF furnace feeding frequency conversion model improves the control accuracy of alloy feeding by estimating and compensating the lag of the actual feeding value, effectively reducing the alloy cost of the enterprise. Without increasing hardware investment, it can achieve significant quality improvement, cost reduction and efficiency improvement.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] (1) The feeding accuracy of the LF furnace was improved from ±15.62% before application to ±10.2%, and the feeding accuracy was improved by 5.42%.

[0019] (2) Eliminate the hidden danger of excessive material addition and abnormal composition caused by the material hanging on the hopper wall and suddenly falling.

[0020] (3) The alloy consumption is reduced by rationally adding materials.

[0021] (4) The number of times alloy is added manually due to insufficient feeding accuracy is reduced, thus ensuring the occupational health of workers.

[0022] (5) Compared with the manual feeding of operators in batches before the application, one-click feeding can be achieved, improving the automation level of the enterprise. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a schematic flow chart of a method for optimizing the control of charging accuracy of a LF refining furnace according to Example 1 of the present invention;

[0024] Figure 2 This is a structural diagram of a control system according to Embodiment 1 of the present invention;

[0025] Figure 3 This is a flow chart of the LF refining furnace charging accuracy optimization control program of Example 1 of the present invention. DETAILED DESCRIPTION

[0026] In order to make the technical solution of the present invention more clearly understood, the technical solution of the present invention is further described in detail below according to specific embodiments and in combination with the accompanying drawings. Obviously, the following embodiments are only part of the embodiments of the present invention and do not constitute a limitation on the technical solution of the present invention. For those of ordinary skill in the art, other embodiments can also be obtained according to the embodiments of the present application without paying creative labor.

[0027] It should be noted that the order of steps described in the method embodiments in the following embodiments does not constitute a limitation on the technical solution of the present invention. For ordinary technicians in this field, without paying any creative labor, they can also reasonably adjust the order of certain steps according to the embodiments of the present application.

[0028] Example 1

[0029] This embodiment provides a method for optimizing the control of charging accuracy of a LF refining furnace. Figure 1 As shown, the following steps are included:

[0030] Step 101, set the corresponding material type compensation coefficient K according to the material type characteristics, as shown in Table 1:

[0031] Table 1 Material compensation coefficient table

[0032] Low Carbon Ferrosilicon Aluminum Ball Ferrotitanium Ferroniobium Low Carbon Ferrochrome Manganese Metal Medium Carbon Ferromanganese High Carbon Ferromanganese 1.0～1.10 1.04～1.08 1.1～1.16 1.25～1.30 1.14～1.20 1.21～1.28 1.19～1.25 1.20～1.25

[0033] Step 102: Design a Smith predictor compensator to compensate for the time lag effect of the feed value, and its transfer function is:

[0034]

[0035] Z is a discrete complex frequency domain operator, which is obtained by discrete Z domain transformation of the time domain transfer function that varies with time, based on the feedback of the deviation between the set value and the actual value of the feeding system.

[0036] Step 103: Based on the original PID controller, a reverse-parallel Smith predictive compensator is added to form a new controller. The control system composed of the new controller (as shown in the dotted box) is as follows: Figure 2 , where X(S) is the set value for feeding and Y(S) is the actual value for feeding.

[0037] The existing conventional controller sets the next control parameter based on the deviation between the actual value of feeding and the set value after the current process is executed; while the controller with the Smith predictor compensator can predict the actual value of feeding before the current process is executed, and optimize the control parameters according to the predicted deviation, thereby reducing the actual deviation value after the process is executed. The new controller outputs the current frequency control parameter to the actuator, controls the feeder inverter, and improves the control accuracy of the weighing and feeding system.

[0038] Step 104: The proportional coefficient P in the PID parameters of the new controller is multiplied by the corresponding material type compensation coefficient K to perform material addition control.

[0039] like Figure 3 The flowchart of the LF refining furnace charging accuracy optimization control program of this embodiment is shown, which specifically includes:

[0040] Collect the set value, actual value and material type of the feeding system;

[0041] Select appropriate material compensation coefficient according to material type;

[0042] The designed Smith predictive compensator (i.e., frequency compensation model) is used to compensate the actual value of the weighing bin charging;

[0043] After compensation, the new controller outputs the given frequency of the frequency converter to control the feeding of the feeder;

[0044] Stop feeding after adding materials;

[0045] After a set delay time (e.g. 5s), the actual value of material addition will be output on the HMI human-machine interface.

[0046] The LF refining furnace charging accuracy optimization control method of the present embodiment sets the material type compensation coefficient K, and the proportional coefficient P in the PID parameter is multiplied by K for output, thereby reducing the significant impact of the material type on the delay; on the basis of the original PID controller, a reverse-parallel Smith predictive compensator is added to form a new controller, and the control parameters are optimized and set according to the estimated deviation, thereby greatly improving the LF furnace charging accuracy.

[0047] Example 2

[0048] This embodiment provides an electronic device, including a processor and a memory, wherein the memory stores a program that can be run on the processor, and when the program is executed by the processor, the steps of the above-mentioned LF refining furnace charging accuracy optimization control method are implemented.

[0049] The above program can be written in one or more programming languages ​​or a combination thereof, including object-oriented programming languages ​​such as Java, Smalltalk, C++, and conventional procedural programming languages ​​such as "C" or similar programming languages. The program code can be executed entirely on the user's computer, partially on the user's computer, as a separate software package, partially on the user's computer and partially on a remote computer, or entirely on the remote computer or server.

[0050] Example 3

[0051] This embodiment provides a computer-readable storage medium storing at least one program, and the at least one program can be executed by at least one processor to implement the steps of the above-mentioned LF refining furnace charging accuracy optimization control method.

[0052] The above storage media include: U disk, mobile hard disk, read-only memory, random access memory, disk or optical disk and other media that can store program code and their combination. With the development of science and technology, the meaning of storage media may become more and more extensive and not limited to tangible media.

[0053] A production test was conducted on a LF furnace in a steel plant, and the accuracy data of the feeding system before and after the application of the method of the present invention were obtained as shown in Tables 2 and 3:

[0054] Table 2 Precision data of feeding system before application (random 10 furnaces)

[0055] Furnace No. Brand Feeding Type Settings Actual value deviation 2345402 HC340LA Ferrotitanium 420 452 0.08 2355025 Q235B Metal Brutal 80 101 0.26 2355305 BG380CL High Carbon Ferromanganese 350 374 0.07 2355310 Q355B Manganese Metal 60 67 0.12 2365340 SCGA440 Aluminum Ball 80 95 0.19 2355200 HC340LA Low Carbon Ferrosilicon 150 165 0.10 2345715 SPHT2 Ferrotitanium 450 486 0.08 2355102 SS400 Aluminum Ball 60 81 0.35 2345797 Q355D Medium Carbon Ferromanganese 135 158 0.17 2355557 45 Low Carbon Ferrochrome 120 138 0.15 Average Deviation 15.62％

[0056] Table 3 Application of the feeding system accuracy data (random 10 furnaces)

[0057] Furnace No. Brand Feeding Type Settings Actual value deviation 2320123 HC340LA Ferrotitanium 450 462 0.03 2321122 Q235B Metal Brutal 100 112 0.12 2331211 BG380CL High Carbon Ferromanganese 250 267 0.07 2338123 Q355B Manganese Metal 80 89 0.11 2348121 SCGA440 Aluminum Ball 30 35 0.17 2351123 HC340LA Low Carbon Ferrosilicon 120 138 0.15 2353120 SPHT2 Ferrotitanium 420 434 0.03 2355102 SS400 Aluminum Ball 40 50 0.25 2366123 Q355D Medium Carbon Ferromanganese 140 148 0.06 2366125 45 Low Carbon Ferrochrome 110 114 0.04 Average Deviation 10.2％

[0058] By comparing the data of the same steel type in the above table, it can be seen that after applying the method of the present invention, the accuracy of the feeding system is improved by 5.42%, and the narrow component hitting of the molten steel and the alloy feeding cost can be effectively controlled. The present invention realizes the compensation of the signal delay of the actual value of the feeding through the frequency model control without adding hardware.

[0059] Those skilled in the art can understand that the above-mentioned embodiments are specific embodiments for implementing the present invention. In addition to the above-mentioned embodiments, the present invention may also have other implementation modes; any technical solutions formed by equivalent replacement or equivalent transformation shall fall within the protection scope required by the present invention.

Claims

1. A method for optimizing the charging accuracy of a LF refining furnace, characterized in that: The steps include: Set material compensation coefficient according to material characteristics; Design the Smith predictor compensator, whose transfer function is: Z is a discrete complex frequency domain operator, which is obtained by discrete Z domain transformation of the time domain transfer function that varies with time, based on the feedback of the deviation between the set value and the actual value of the feeding system; The new controller is formed by connecting the Smith predictive compensator designed in reverse parallel to the original PID controller. The proportional coefficient P in the PID parameters of the new controller is multiplied by the corresponding material compensation coefficient to perform material addition control.

2. The LF refining furnace charging accuracy optimization control method according to claim 1, characterized in that: The material compensation coefficients are shown in the following table: 。 3. An electronic device, comprising a processor and a memory, wherein the memory stores a program that can be run on the processor, characterized in that: When the program is executed by the processor, the steps of the LF refining furnace charging accuracy optimization control method according to any one of claims 1 to 2 are implemented.

4. A computer-readable storage medium storing at least one program, characterized in that: The at least one program can be executed by at least one processor to implement the steps of the LF refining furnace charging accuracy optimization control method described in any one of claims 1-2.

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