Method for optimizing inner diameter of nozzle of secondary cooling chamber of continuous casting machine, nozzle and cooling system

Abstract

The invention relates to the technical field of continuous casting machines, in particular to a nozzle inner diameter optimization method for a secondary cooling chamber of a continuous casting machine, a nozzle and a cooling system. According to the nozzle inner diameter optimization method for the secondary cooling chamber of the continuous casting machine, by collecting the initial inner diameter and the initial spraying amount of the initial nozzle and combining the temperature difference before and after cooling of the casting blank, the optimal inner diameter and the optimal spraying amount of optimal spraying for cooling of the casting blank are calculated, and therefore the cooling effect on the casting blank is further improved. Nozzles with different inner diameters can be designed according to steel type characteristics of casting blanks made of different materials, so that a proper nozzle can be selected when a certain casting blank needs to be cooled, the cooling effect is improved, and then the production efficiency is improved.

Description

Technical Field

[0001] The invention relates to the technical field of continuous casting machines, and in particular to a method for optimizing the inner diameter of a nozzle of a second cooling chamber of a continuous casting machine, a nozzle and a cooling system. Background Art

[0002] The secondary cooling chamber of the continuous casting machine is an important part of the continuous casting machine, which is mainly used for secondary cooling of the ingot pulled out of the crystallizer. During the continuous casting process, the function of the crystallizer is to make the molten steel initially solidify to form a shell with a certain thickness, while the secondary cooling chamber is to further cool the ingot to make it completely solidified and reach a temperature range suitable for subsequent processing.

[0003] However, since the steel properties of different materials are different, if one nozzle is used to cool the ingot, the cooling effect will be poor. Summary of the invention

[0004] The purpose of the present invention includes providing a method for optimizing the inner diameter of a nozzle of a secondary cooling chamber of a continuous casting machine, a nozzle and a cooling system, which can improve the cooling effect.

[0005] The embodiments of the present invention can be implemented as follows:

[0006] In a first aspect, the present invention provides a method for optimizing the inner diameter of a nozzle of a secondary cooling chamber of a continuous casting machine, comprising:

[0007] Collect the initial inner diameter D of the initial nozzle 1 and the initial injection quantity Q 1 ;

[0008] The surface temperature of the ingot is detected by a temperature sensor to collect the temperature change ΔT before and after the ingot is cooled;

[0009] Using the formula ΔT = k·Q 2 + b, calculate the optimal injection amount Q for cooling the billet 2 ;

[0010] Using formula D 2 =D 1 ·√(Q 1 / Q 2 ), calculate the optimal inner diameter D of the cooling billet 2 ;

[0011] Wherein, k represents the proportional coefficient of the influence of the amount of coolant spray on the temperature change of the casting surface;

[0012] b is the change in surface temperature of the ingot when the amount of coolant injection is zero.

[0013] In an optional embodiment, it also includes:

[0014] Select or manufacture an inner diameter of D 2 The best nozzle for

[0015] Replace the initial nozzle with the optimal nozzle;

[0016] Verify the injection amount of the optimal nozzle to obtain the actual injection amount Q 3 .

[0017] In an optional embodiment, it also includes:

[0018] If the optimal injection quantity Q 2 and the actual injection quantity Q 3 The ratio between 3 / Q 2 <70%, then replace the optimal nozzle with the initial nozzle;

[0019] Re-collect the initial inner diameter D of the initial nozzle 1 and the initial injection quantity Q 1 , and use the formula to calculate the optimal injection quantity Q 2 .

[0020] In an optional embodiment, it also includes:

[0021] If the optimal injection quantity Q 2 and the actual injection quantity Q 3 The ratio between 3 / Q 2 <70%, clean the best nozzle.

[0022] In a second aspect, the present invention provides a nozzle for a secondary cooling chamber of a continuous casting machine, wherein the inner diameter of the nozzle is obtained according to the aforementioned method for optimizing the inner diameter of the nozzle for a secondary cooling chamber of a continuous casting machine.

[0023] In an optional embodiment, the nozzle is provided with a slag discharge hole for allowing a cleaning member to pass through to clean iron slag and dirt.

[0024] In an optional embodiment, the inner diameter of the nozzle of the secondary cooling chamber of the continuous casting machine is D, wherein 30 mm ≤ D ≤ 50 mm.

[0025] In a third aspect, the present invention provides a cooling system for a secondary cooling chamber of a continuous casting machine, comprising a temperature sensor, a pipeline assembly, an initial nozzle and the nozzle of the aforementioned secondary cooling chamber of the continuous casting machine, wherein the temperature sensor is connected to the pipeline assembly; the initial nozzle and one of the nozzles are connected to the pipeline assembly and communicated with the pipeline assembly; the temperature sensor is used to detect the surface temperature of the ingot.

[0026] In an optional embodiment, a processor is further included, the processor is electrically connected to the temperature sensor, and is used to receive the surface temperature of the casting billet detected by the temperature sensor, and calculate the temperature change ΔT, the optimal injection amount Q 2And the optimal inner diameter D 2 .

[0027] In an optional embodiment, the cooling system of the secondary cooling chamber of the continuous casting machine further includes an injection amount sensor connected to the nozzle, and the injection amount sensor is used to detect the injection amount of the nozzle.

[0028] The beneficial effects of the method for optimizing the inner diameter of the nozzle of the secondary cooling chamber of the continuous casting machine, the nozzle of the secondary cooling chamber of the continuous casting machine, and the cooling system of the secondary cooling chamber of the continuous casting machine provided by the embodiments of the present invention include:

[0029] The nozzle inner diameter optimization method of the secondary cooling chamber of the continuous casting machine can collect the initial inner diameter and initial injection amount of the initial nozzle, and combine the temperature difference before and after the cooling of the billet to calculate the optimal inner diameter and optimal injection amount for the optimal injection of the billet, thereby further improving the cooling effect of the billet.

[0030] Therefore, the present invention can design nozzles with different inner diameters according to the steel grade characteristics of the ingots of different materials, so that when a certain ingot needs to be cooled, a suitable nozzle can be selected, thereby improving the cooling effect and further improving the production efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0032] Figure 1 A schematic flow chart of a method for optimizing the inner diameter of a nozzle in a second cooling chamber of a continuous casting machine provided in this embodiment;

[0033] Figure 2 A schematic diagram of the flow of the acquisition steps and calculation steps provided in this embodiment;

[0034] Figure 3 A flowchart of the verification steps provided in this embodiment. DETAILED DESCRIPTION

[0035] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0036] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0037] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0038] In the description of the present invention, it should be noted that if the terms "upper", "lower", "inside", "outside", etc. appear to indicate an orientation or position relationship, they are based on the orientation or position relationship shown in the accompanying drawings, or are the orientation or position relationship in which the product of the invention is usually placed when used. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0039] In addition, the terms “first”, “second”, etc., if used, are merely used to distinguish between the descriptions and should not be understood as indicating or implying relative importance.

[0040] It should be noted that, in the absence of conflict, the features in the embodiments of the present invention may be combined with each other.

[0041] After the high-temperature molten steel is poured into the continuous casting machine, the high-temperature molten steel crystallizes in the continuous casting machine to form a billet shell, and the continuous casting machine pulls out the billet shell, and then cools the billet through a cooling system, so that the billet is completely solidified.

[0042] It is understandable that the continuous casting machine can operate on different steel materials. However, the thermal conductivity and solidification speed of different steel materials are different. Therefore, the cooling efficiency of the ingots made of different steel materials using the same cooling system is also different.

[0043] In order to improve the cooling efficiency of the ingot, the present invention optimizes the nozzle of the secondary cooling chamber of the continuous casting machine, and changes the spray amount of the nozzle by adjusting the inner diameter of the nozzle. Therefore, the present invention provides a method for optimizing the inner diameter of the nozzle of the secondary cooling chamber of the continuous casting machine, so as to select or manufacture nozzles with suitable inner diameters according to the characteristics of different steels, thereby improving the cooling effect of the ingot.

[0044] Please refer to Figure 1 , Figure 1 The schematic flow chart of the method for optimizing the inner diameter of the nozzle of the second cooling chamber of the continuous casting machine provided in this embodiment. The method for optimizing the inner diameter of the nozzle of the second cooling chamber of the continuous casting machine includes three main steps:

[0045] S1: Collect relevant data;

[0046] S2: Calculate the optimal inner diameter of the nozzle for the target ingot based on the collected data;

[0047] S3: To verify whether the efficiency of the nozzle with the optimal inner diameter is improved.

[0048] It should be noted that, in order to optimize the inner diameter of the nozzle, the present invention needs to provide a cooling system, which includes a temperature sensor, a pipeline assembly and an original nozzle, the temperature sensor and the original nozzle are both connected to the pipeline assembly, and the coolant in the pipeline assembly is sprayed from the nozzle to cool the ingot; and the temperature sensor is used to collect the temperature change ΔT before and after the ingot is cooled, wherein ΔT can be calculated by formula 1, which is as follows:

[0049] ΔT=T max -T min .

[0050] Among them, T max is the temperature of the ingot before cooling, T min It is the temperature at which the ingot is completely solidified.

[0051] Please refer to Figure 2 , Figure 2 The flowchart of the acquisition step and the calculation step provided in this embodiment. Specifically, S1 also includes the following steps:

[0052] S11: Connect the pipe assembly, temperature sensor and original nozzle;

[0053] S12: Detecting the surface temperature of the ingot by a temperature sensor, and obtaining the temperature change ΔT of the ingot surface by using formula 1;

[0054] S13: Collect the initial inner diameter D of the initial nozzle 1 and the initial injection quantity Q 1 .

[0055] It should be noted that, in other embodiments, S13 may also be performed before S11, and the initial inner diameter D may be collected first. 1 and the initial injection quantity Q 1 , that is, the steps in other embodiments are S13-S11-S12.

[0056] Further, after collecting the initial inner diameter D 1 , initial injection quantity Q 1 And the temperature change of the billet ΔT, the optimal injection amount Q can be calculated based on the collected data 2 and the optimal inner diameter D 2 .

[0057] In this embodiment, a high-precision cooling medium flow rate, pressure and ingot temperature relationship model for casting speeds of different steel grades can be established through a large amount of data collection and in-depth analysis.

[0058] Taking plain carbon steel as an example, please refer to Figure 2 Specifically, S2 further includes the following steps:

[0059] S21: Using formula 2: ΔT = k·Q 2 + b, calculate the optimal injection amount Q for cooling the billet 2 ;

[0060] S22: Using Formula 3: D 2 =D 1 ·√(Q 1 / Q 2 ), calculate the optimal inner diameter D of the cooling billet 2 .

[0061] It can be understood that Formula 2 and Formula 3 can be combined into Formula 4: 2 =D 1 ·√((k·Q 1 ) / (ΔT-b)), so the optimal inner diameter D can be directly calculated using formula 4 2 ;

[0062] It should be noted that k represents the proportional coefficient of the influence of the coolant injection amount on the surface temperature change of the ingot; b is the change in the surface temperature of the ingot when the coolant injection amount is zero. k and b are coefficients obtained by fitting and optimizing hundreds of sets of experimental data.

[0063] Since the spraying amount of the nozzle is affected by its inner diameter, that is, the spraying amount of nozzles with different inner diameters is not the same, the operator can refer to the optimal inner diameter to select or manufacture the nozzle, so that the spraying amount of the selected or manufactured nozzle reaches the optimal spraying amount, thereby improving the cooling effect on the casting.

[0064] The initial nozzle related data is shown in Table 1, which is as follows:

[0065]

[0066] The relevant data of the best nozzle are shown in Table 2. Table 2 is as follows:

[0067]

[0068] It should be noted that, during use, iron slag and scale accumulation may cause partial blockage, resulting in the actual effective injection amount being approximately 70% of the calculated injection amount.

[0069] According to the actual effective injection volume of the optimal nozzle and the actual effective injection volume of the initial nozzle, it can be seen that the injection volume of the optimal nozzle is increased by about 97.9% relative to the initial nozzle. It can be understood that due to the increase in injection volume, the contact area between the billet and the coolant increases, and the flow rate of the coolant will also increase. The coolant can quickly take away a large amount of heat on the surface of the billet, thereby improving the cooling effect. In addition, due to the accelerated flow rate of the coolant, its ability to flush iron slag and scale is enhanced, thereby improving the blockage situation and further improving the cooling effect on the billet.

[0070] Moreover, if the nozzle is larger than 40.2 mm, the pressure will be too high and the spraying range will be wide, so it is impossible to concentrate the strong cold spraying on the ingot. Therefore, the value range of the inner diameter D of the nozzle is 30 mm-50 mm, and the initial nozzle also adopts the minimum inner diameter of 30 mm that can cool the ingot.

[0071] For different steels, due to the different characteristics of the steels such as the melting point ratio, the temperature change ΔT of the ingots of different steels will also be different. Therefore, the optimal inner diameter obtained after calculation will also be different.

[0072] Therefore, suitable nozzles can be selected or manufactured for various ingots made of different steel materials, thereby improving the cooling effect on different ingots.

[0073] It should be noted that after obtaining the optimal inner diameter, the obtained inner diameter must be verified first to avoid errors in the previous steps, which may result in the obtained inner diameter being not the optimal inner diameter, thereby affecting the cooling effect on the ingot.

[0074] Please refer to Figure 3 , Figure 3 A flow chart of the verification steps provided in this embodiment. Specifically, S3 also includes the following steps:

[0075] S31: Select or manufacture inner diameter D 2 The best nozzle for

[0076] S32: replacing the initial nozzle with the optimal nozzle;

[0077] S33: Verify the injection amount of the optimal nozzle to obtain the actual injection amount Q 3 ;

[0078] S34: If the optimal injection quantity Q 2 and the actual injection quantity Q 3 The ratio between 3 / Q 2 <70%, then replace the optimal nozzle with the initial nozzle;

[0079] Re-collect the initial inner diameter D of the initial nozzle 1and the initial injection quantity Q 1 , and use the formula to calculate the optimal injection quantity Q 2 ;

[0080] S35: If the optimal injection quantity Q 2 and the actual injection quantity Q 3 The ratio between 3 / Q 2 <70%, clean the best nozzle.

[0081] It should be noted that the cooling system of the second cooling chamber of the continuous casting machine in this embodiment also includes an injection amount sensor for detecting the injection amount of the optimal nozzle to detect the actual injection amount Q 3 .

[0082] If the optimal injection quantity Q 2 and the actual injection quantity Q 3 The difference between them is greater than 1m 3 / h, you can clean the best nozzle first to remove the dirt and sediment in the best nozzle; if the difference is still greater than 1m 3 / h, there may be an error in the collection and calculation process, and re-collection and calculation are required; if the data obtained by re-collection and calculation are the same as the previous data, there may be an error in the selection of the nozzle, or a large error in the manufacturing process.

[0083] If the actual injection volume Q is 3 and the optimal injection quantity Q 2 The difference between the two is 1m 3 / h; after a period of use, the actual injection volume Q 3 and the optimal injection quantity Q 2 The difference between them is greater than 1m 3 / h, it is possible that during use, sediment has gradually accumulated, thus affecting the injection volume.

[0084] In order to facilitate cleaning of the nozzle, in this embodiment, a slag discharge hole is provided on the nozzle for allowing a cleaning member to pass through to clean iron slag and dirt.

[0085] Based on the above optimization method, this embodiment provides a cooling method for a secondary cooling chamber of a continuous casting machine, which includes a temperature sensor, a processor, an injection amount sensor, a pipeline assembly, an initial nozzle, and a nozzle of a secondary cooling chamber of a continuous casting machine.

[0086] First, connect the initial nozzle to the pipeline assembly and make it communicate with the pipeline assembly. Then, use the initial nozzle to spray coolant to cool a billet. Use a temperature sensor to collect the temperature of the billet before and after cooling, and use an injection amount sensor to collect the injection amount of the initial nozzle.

[0087] In this embodiment, the temperature sensor, injection amount sensor and processor are all connected to the pipeline assembly, so that the temperature sensor is used to detect the temperature of the surface of the ingot, and the injection amount sensor is used to detect the injection amount of the initial nozzle and the nozzle of the second cooling chamber of the continuous casting machine.

[0088] The processor receives the temperature signal from the temperature sensor and the injection amount signal from the injection amount sensor, and calculates the temperature change ΔT and the optimal injection amount Q in combination with the inner diameter of the initial nozzle. 2 And the optimal inner diameter D 2 Subsequently, the nozzle for the secondary cooling chamber of the continuous casting machine is selected or manufactured according to the optimal inner diameter and the optimal injection amount.

[0089] It can be understood that the inner diameter of the nozzle of the second cooling chamber of the continuous casting machine is calculated based on the inner diameter optimization method of the nozzle of the second cooling chamber of the continuous casting machine. Therefore, the nozzle of the second cooling chamber of the continuous casting machine is the optimal nozzle.

[0090] Finally, the original nozzle is removed from the pipe assembly, and the nozzle of the second cooling chamber of the continuous casting machine is connected to the pipe assembly and communicated with it, thereby cooling the remaining ingots. It should be noted that the ingots cooled by the nozzle of the second cooling chamber of the continuous casting machine and the ingots cooled by the initial nozzle are the same batch of ingots, and are formed by the same type of steel.

[0091] In summary, the present invention provides a method for optimizing the inner diameter of the nozzle of the second cooling chamber of a continuous casting machine. By collecting the initial inner diameter and the initial injection amount of the initial nozzle and combining the temperature difference before and after the cooling of the billet, the optimal inner diameter and the optimal injection amount of the optimal injection for cooling the billet are calculated, thereby further improving the cooling effect on the billet.

[0092] Therefore, the present invention can design nozzles with different inner diameters according to the steel grade characteristics of ingots of different materials, so that when a certain ingot needs to be cooled, a suitable nozzle can be selected, thereby improving the cooling effect and further improving production efficiency; and it can save energy costs and avoid waste. According to statistics, energy costs of approximately RMB 3.276 million can be saved each year.

[0093] The above description is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by a technician familiar with the technical field within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention.

Claims

1. A method for optimizing the inner diameter of a nozzle in a secondary cooling chamber of a continuous casting machine, characterized in that: include: Collect the initial inner diameter D1 and initial injection volume Q1 of the initial nozzle; The surface temperature of the ingot is detected by a temperature sensor to collect the temperature change ΔT before and after the ingot is cooled; The optimum injection amount Q2 for cooling the ingot is calculated using the formula ΔT=k·Q2+b; The optimum inner diameter D2 for cooling the ingot is calculated using the formula D2=D1·√(Q1 / Q2); Wherein, k represents the proportional coefficient of the influence of the amount of coolant spray on the temperature change of the casting surface; b is the change in the surface temperature of the ingot when the injection amount of the coolant is zero.

2. The method for optimizing the inner diameter of the nozzle of the secondary cooling chamber of the continuous casting machine according to claim 1, characterized in that: Also includes: Select or manufacture the best nozzle with inner diameter D2; replacing the initial nozzle with the optimal nozzle; The injection amount of the optimal nozzle is verified to obtain the actual injection amount Q3.

3. The method for optimizing the inner diameter of the nozzle of the second cooling chamber of the continuous casting machine according to claim 2, characterized in that: Also includes: If the ratio between the optimal injection amount Q2 and the actual injection amount Q3, Q3 / Q2<70%, then the optimal nozzle is replaced with the initial nozzle; The initial inner diameter D1 and the initial injection amount Q1 of the initial nozzle are collected again, and the optimal injection amount Q2 is calculated using a formula.

4. The method for optimizing the inner diameter of the nozzle of the secondary cooling chamber of the continuous casting machine according to claim 2, characterized in that: Also includes: If the ratio between the optimal injection amount Q2 and the actual injection amount Q3, Q3 / Q2<70%, the optimal nozzle is cleaned.

5. A nozzle for the second cooling chamber of a continuous casting machine, characterized in that: The inner diameter of the nozzle is obtained by the method for optimizing the inner diameter of the nozzle of the secondary cooling chamber of a continuous casting machine according to any one of claims 1-4.

6. The nozzle of the secondary cooling chamber of the continuous casting machine according to claim 5, characterized in that: The nozzle is provided with a slag discharge hole for allowing a cleaning member to pass through to clean iron slag and dirt.

7. The nozzle of the secondary cooling chamber of the continuous casting machine according to claim 5, characterized in that: The inner diameter of the nozzle of the second cooling chamber of the continuous casting machine is D, wherein 30 mm ≤ D ≤ 50 mm.

8. A cooling system for a secondary cooling chamber of a continuous casting machine, characterized in that: It comprises a temperature sensor, a pipeline assembly, an initial nozzle and a nozzle of a secondary cooling chamber of a continuous casting machine according to any one of claims 5 to 7, wherein the temperature sensor is connected to the pipeline assembly; the initial nozzle and one of the nozzles are connected to the pipeline assembly and communicated with the pipeline assembly; the temperature sensor is used to detect the surface temperature of the ingot.

9. The continuous casting machine secondary cooling chamber cooling system according to claim 8, characterized in that: The system further comprises a processor, which is electrically connected to the temperature sensor and is used to receive the surface temperature of the ingot detected by the temperature sensor and calculate the temperature change ΔT, the optimal injection amount Q2 and the optimal inner diameter D2.

10. The continuous casting machine secondary cooling chamber cooling system according to claim 8, characterized in that: The continuous casting machine secondary cooling chamber cooling system further comprises an injection amount sensor connected to the nozzle, and the injection amount sensor is used to detect the injection amount of the nozzle.

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