A total flow control and compensation method for plate zone cooling of aluminum cold rolling mill

Abstract

The present invention provides a method for controlling and compensating the total flow rate of plate-shaped zoned cooling of an aluminum cold rolling mill. A plate-shaped measuring roller is installed on the outlet side of the aluminum cold rolling mill. The plate-shaped I value of each zone is calculated based on the actual plate-shaped radial force measured by the plate-shaped measuring roller. Then, the zoned cooling system is PID controlled according to the size of the plate-shaped I value of each zone, and the given flow rate ratio required for injection of the nozzles in each zone on the injection beam is calculated, wherein the pressure sensors in each zone arranged on the plate-shaped measuring roller correspond one-to-one to the position distribution of the nozzle beams in each zone on the injection beam. The percentage of the given flow rate ratio required for injection of the nozzles in each zone on the injection beam is determined by the given total flow rate of the zoned cooling #imgabs0# and the given flow rate ratio required for injection of each nozzle on the injection beam. Finally, the flow rate is adjusted by controlling the injection valve through a high-speed pulse. The application of this technical solution can realize the adjustment of the roll gap by controlling the cooling speed in different zones, thereby reducing the adverse effects of the change in the roll gap on the plate shape of the strip.

Description

Technical Field

[0001] The invention relates to the technical field of rolling, in particular to a total flow control and compensation method for plate-type zone cooling of an aluminum cold rolling mill. Background Art

[0002] Symmetrical thermal deformation of the rolls during the rolling process of an aluminum cold rolling mill can be controlled through roll bending and roll shifting. However, the random, uneven, and asymmetric thermal expansion of the rolls requires precisely calculated cooling rates to control the asymmetric deformation. Zoned cooling in an aluminum cold rolling mill controls the cooling rate of different sections of the rolls during the rolling process. The aluminum rolling process generates significant heat, which can cause the rolls to expand and deform. Uneven heat distribution can also alter the roll gap, affecting the strip shape. Summary of the Invention

[0003] In view of this, the purpose of the present invention is to provide a method for controlling and compensating the total flow rate of zoned cooling of an aluminum cold rolling mill, thereby adjusting the roll gap by controlling the cooling speed in different areas and reducing the adverse effects of the roll gap changes on the strip shape.

[0004] To achieve the above-mentioned purpose, the present invention adopts the following technical solutions: a method for controlling and compensating the total flow rate of plate-shaped zone cooling of an aluminum cold rolling mill, wherein a plate-shaped measuring roller is installed on the outlet side of the aluminum cold rolling mill, and the plate-shaped I value of each zone is calculated according to the actual plate-shaped radial force measured by the plate-shaped measuring roller, and then the zone cooling system is PID controlled according to the size of the plate-shaped I value of each zone, and the given size ratio of the flow rate required to be sprayed by the nozzle of each zone on the spray beam is calculated, wherein the pressure sensors of each zone arranged on the plate-shaped measuring roller correspond to the position distribution of the nozzle beam of each zone on the spray beam one by one; through the given value L of the total flow rate of the zone cooling 总ref The percentage L of the flow rate given by each nozzle on the spray beam is determined by the given size ratio of the flow rate given by each nozzle in each area of the spray beam. ref [i], the edge area where the rolled coil is pressed against one side of the plate roller is set as zone i, and finally the flow rate is adjusted by the high-speed pulse control injection valve;

[0005] The percentage of the given flow rate required to be sprayed by the nozzles in each zone on the spray beam L ref [i] and the given value of the total cooling flow of the zone L 总ref The following relationship exists: The edge area on the other side of the rolling mill coil pressed against the plate shape measuring roller is set as the i+n area.

[0006] In a preferred embodiment, the roll gap power is calculated based on the rolling speed ν, rolling force F, and strip width W of the aluminum cold rolling mill. Then calculate the percentage of the given value L of the automatic control zone cooling flow according to the roll gap power ratio conversion 自动ref , the calculation formula is as follows:

[0007]

[0008] Among them, P max is the maximum roll gap power, P min is the minimum value of the roll gap power, L max is the maximum cooling flow rate of the partition, L min is the minimum cooling flow rate of the partition, L 自动ref ∈(L min ,L max ).

[0009] In a preferred embodiment, the percentage L of the given value of the compensation zone cooling flow is calculated based on the different alloys and different reduction ratios of the rolled materials. 补偿ref , where the hardness of different alloys corresponds to different partition cooling flow compensation coefficients a (a∈(0,1)), and the greater the hardness, the greater the compensation coefficient; different partition cooling flow compensation coefficients b are calculated by proportional conversion of different reductions h, b∈(0,1), and the calculation formula is as follows:

[0010] h=h 入口 -h 出口

[0011]

[0012] Among them, h 入口 is the strip entrance thickness, h 出口 is the strip outlet thickness, h max is the maximum value of the compression, h min is the minimum value of the reduction, b max is the maximum value of the compensation coefficient, b min is the minimum value of the compensation coefficient, b∈(b min ,b max )∈(0,1);

[0013] According to the different alloys and different reduction ratios of the rolled materials, the percentage L of the given value of the compensation zone cooling flow is calculated. 补偿ref =a*b*10%.

[0014] In a preferred embodiment, the percentage L of the given value of the cooling flow rate of the partition is manually adjusted. 手动ref , then the percentage of the total flow rate of the zone cooling is given by L 总ref =L 自动ref +L 补偿ref +L 手动ref .

[0015] Compared with existing technologies, the present invention offers the following advantages: By controlling the cooling rate in different zones, the roll gap is adjusted, mitigating the adverse effects of roll gap variations on strip shape. On an aluminum cold rolling mill, parallel rolls are equipped with a coolant spray beam with multiple nozzles. Each nozzle is equipped with a control valve. By adjusting the coolant spray rate, the valve regulates the temperature of different roll zones, thereby adjusting and changing the thermal crown of the rolls and, in turn, the strip shape. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 A schematic diagram of zoned cooling control according to a preferred embodiment of the present invention;

[0017] Figure 2 The roll gap power P and the percentage L of the given value of the zone cooling flow rate in the preferred embodiment of the present invention are 自动ref Schematic diagram of the relationship between them;

[0018] Figure 3 Schematic diagram of the relationship between different reduction amounts h and zoned cooling flow compensation coefficients b in a preferred embodiment of the present invention;

[0019] Figure 4 Schematic diagram of percentage of given value of injection flow rate in each partition according to a preferred embodiment of the present invention;

[0020] Figure 5 This is a bar chart of the given values of the injection flow rate in each partition according to the preferred embodiment of the present invention. DETAILED DESCRIPTION

[0021] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0022] It should be noted that the following detailed descriptions are illustrative and intended to provide further explanation of the present application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which the present application belongs.

[0023] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application; as used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form, and it should be understood that when the terms "comprise" and / or "include" are used in this specification, they indicate the presence of features, steps, operations, devices, components and / or their combinations.

[0024] A method for controlling and compensating the total flow rate of plate-shaped zone cooling of an aluminum cold rolling mill is disclosed. A plate-shaped measuring roller is installed on the outlet side of the aluminum cold rolling mill. The plate-shaped I value of each zone is calculated based on the actual plate-shaped radial force measured by the plate-shaped measuring roller. The zone cooling system is then PID-controlled based on the plate-shaped I value of each zone, and the flow rate ratio required for the nozzles of each zone on the spray beam is calculated. The pressure sensors of each zone provided on the plate-shaped measuring roller correspond to the position distribution of the nozzle beams of each zone on the spray beam. The total flow rate of the zone cooling is given by the given value L. 总ref The percentage L of the flow rate given by each nozzle on the spray beam is determined by the given size ratio of the flow rate given by each nozzle in each area of the spray beam. ref [i], the edge area where the rolled coil is pressed against one side of the plate roller is set as zone i, and finally the flow rate is adjusted by high-speed pulse control injection valve. The schematic diagram of zone cooling control is shown in Figure 1 As shown;

[0025] The percentage of the given flow rate required to be sprayed by the nozzles in each zone on the spray beam L ref [i] and the given value of the total cooling flow of the zone L 总ref The following relationship exists: The edge area on the other side of the rolling mill coil pressed against the plate shape measuring roller is set as the i+n area.

[0026] According to the rolling speed ν (unit: m / s), rolling force F (unit: KN), and strip width W (unit: m) of the aluminum cold rolling mill, the roll gap power is calculated. (Unit: KW / m). Then calculate the percentage of the given value L of the automatic control zone cooling flow according to the roll gap power ratio conversion. 自动ref (Unit: %), the calculation formula is as follows:

[0027]

[0028] Among them, P max is the maximum roll gap power, P min is the minimum value of the roll gap power, L max is the maximum cooling flow rate of the partition, L min is the minimum cooling flow rate of the partition, L 自动ref ∈(L min ,L max Roll gap power P and percentage of given value of zone cooling flow L 自动ref The relationship between Figure 2 shown.

[0029] According to the different alloys and different reduction ratios of the rolled materials, the percentage L of the given value of the compensation zone cooling flow is calculated. 补偿ref, where the hardness of different alloys corresponds to different partition cooling flow compensation coefficients a (a∈(0,1)), and the greater the hardness, the greater the compensation coefficient, as shown in Table 1.

[0030] Table 1 - Different zone cooling flow compensation coefficients for different alloy hardness

[0031]

[0032] Different partition cooling flow compensation coefficients b are calculated by proportional conversion of different reduction amounts h (unit: um), b∈(0,1), and the calculation formula is as follows:

[0033] h=h 入口 -h 出口

[0034]

[0035] Among them, h 入口 is the strip entrance thickness, h 出口 is the strip outlet thickness, h max is the maximum value of the compression, h min is the minimum value of the reduction, b max is the maximum value of the compensation coefficient, b min is the minimum value of the compensation coefficient, b∈(b min ,b max )∈(0,1);

[0036] The relationship between different pressure reduction h and partition cooling flow compensation coefficient b, such as Figure 3 shown.

[0037] According to the different alloys and different reduction ratios of the rolled materials, the percentage L of the given value of the compensation zone cooling flow is calculated. 补偿ref =a*b*10%(unit:%,L 补偿ref Maximum value 10%).

[0038] Manually adjust the percentage of the given value of the cooling flow rate of the partition L 手动ref , then the percentage of the total flow rate of the zone cooling is given by L 总ref =L 自动ref +L 补偿ref +L 手动ref .

[0039] Let me explain this with an example:

[0040] 1. Aluminum cold rolling mill rolling alloy 3104, width W: 1.79m, entrance thickness h 入口 : 480um, outlet thickness h 出口: 250um strip, at this time the rolling speed ν is about 14.5m / s, the rolling force F is about 4980KN, and the roll gap power is calculated to be Then calculate the percentage L of the given value of the automatic control zone cooling flow rate according to the roll gap power ratio conversion 自动ref (Unit: %), the calculation formula is as follows:

[0041]

[0042] (where P max The maximum power of the roller gap is 60000kw / m; P min The minimum power of the roller gap is 2000kw / m; L max The maximum cooling flow rate of the partition is 50%. min The minimum cooling flow rate for each zone is 30%.

[0043] 2. According to the different alloys and different reduction ratios of the rolled materials, calculate the percentage of the given value of the compensation zone cooling flow L 补偿ref (Unit: %), where different alloy hardnesses correspond to different zone cooling flow compensation coefficients a (a∈(0,1)). The greater the hardness, the greater the compensation coefficient, as shown in Table 2. When the aluminum cold rolling mill rolls alloy 3104 strip, the zone cooling flow compensation coefficient a=0.625.

[0044] Table 2 - Different zone cooling flow compensation coefficients for different alloy hardness

[0045] alloy 1 series 3 series 5 series 6 series 7 series 8 series coefficient 0.375 0.625 1 0.5 0.75 0.45

[0046] Different partition cooling flow compensation coefficients b (b∈(0,1)) are calculated by proportional conversion of different reductions h (unit: μm). When the aluminum cold rolling mill rolls strip with an inlet thickness of 480 μm and an outlet thickness of 250 μm, the calculation formula of the partition cooling flow compensation coefficient b is as follows:

[0047] h=h 入口 -h 出口 =480-250=230um

[0048]

[0049] Among them, h max The maximum value of the pressing amount is 5000um; h min The minimum value of the pressing amount is 100um; b max is the maximum value of the compensation coefficient, value: 0.9; b min The minimum value of the compensation coefficient is 0.3.

[0050] Thus, the percentage L of the given value of the compensation zone cooling flow is calculated based on the different alloys and different reduction ratios of the rolled materials. 补偿ref =a*b*10=0.625*0.316*10%=1.975% (unit: %).

[0051] The operator manually adjusts the percentage of the given value of the cooling flow rate of the partition on the operation screen. 手动ref =0 (unit:%), then the percentage of the total flow rate of the zone cooling is L 总ref =L 自动ref +L 补偿ref +L 手动ref =43.22+1.975+0≈45.2%.

[0052] Total cooling flow rate setpoint L by zone 总ref The percentage L of the flow rate given by each nozzle on the spray beam can be determined by the given size ratio of the flow rate given by each nozzle on the spray beam. ref [i] (Unit: %), the edge area where the rolled coil is pressed against one side of the plate roller is defined as area i), and finally the flow rate is adjusted by high-speed pulse control of the injection valve. The percentage of the flow rate given by the nozzles in each area of the injection beam is L ref [i] and the given value of the total cooling flow of the zone L 总ref The following relationship exists: (The edge area where the rolled coil is pressed against the other side of the plate roller is called the i+n area).

[0053] The aluminum rolling mill has a total of 66 zones for the plate rollers and zoned spray beams, 50 zones in total from 1 to 25 and 42 to 66, with each zone spaced 26mm apart, and 16 zones in total from 26 to 41, with each zone spaced 52mm apart. The strip width edge coverage area is greater than 85% of the interval, and the zoned cooling spray in this area will be controlled according to the percentage of the given value of the total zone cooling flow rate. For the aluminum cold rolling mill rolling strips with a width of W: 1.79m, the edge areas are zones 8 and 59. The percentage of the given value of the spray flow rate of each zone in the 66 zones of the zoned cooling spray beam (such as Figure 4 As shown) and the histogram of the given value of the injection flow rate of each partition (as shown Figure 5 As shown), calculate the percentage L of the given value of the injection flow of each partition on the injection beam ref [i] Average value:

[0054]

[0055] Wherein, i is equal to 8 and n is 51.

Claims

1. A method for controlling the total flow rate of plate-type zone cooling in an aluminum cold rolling mill, characterized in that: The roll gap power is calculated based on the rolling speed v, rolling force F, and strip width W of the aluminum cold rolling mill. Then calculate the percentage L of the given value of the automatic control zone cooling flow rate according to the roll gap power ratio conversion 自动ref , the calculation formula is as follows: Among them, P max is the maximum roll gap power, P min is the minimum value of the roll gap power, L max is the maximum cooling flow rate of the partition, L min is the minimum cooling flow rate of the partition, L 自动ref ∈(L min , L max ); According to the different alloys and different reduction ratios of the rolled materials, the percentage L of the given value of the compensation zone cooling flow is calculated. 补偿ref , where the hardness of different alloys corresponds to different partition cooling flow compensation coefficients a, a∈(0,1). The greater the hardness, the greater the compensation coefficient. Different partition cooling flow compensation coefficients b, b∈(0,1) are calculated by proportional conversion of different reductions h. The calculation formula is as follows: h=h 入口 -h 出口 Among them, h 入口 is the strip entrance thickness, h 出口 is the strip outlet thickness, h max is the maximum value of the reduction, h min is the minimum value of the reduction, b max is the maximum value of the compensation coefficient, b min is the minimum value of the compensation coefficient, b∈(b min , b max )∈(0,1); According to the different alloys and different reduction ratios of the rolled materials, the percentage L of the given value of the compensation zone cooling flow is calculated. 补偿ref =a*b*10%; Manually adjust the percentage of the given value of the cooling flow rate of the partition L 手动ref , then the percentage of the total flow rate given by the zone cooling is L 总ref =L 自动ref +L 补偿ref +L 手动ref ; A plate shape measuring roller is installed on the outlet side of the aluminum cold rolling mill. According to the actual plate shape radial force measured by the plate shape measuring roller, the plate shape I value of each partition is calculated. Then, the zone cooling system is PID controlled by the size of the plate shape I value of each partition, and the flow rate given size ratio required by the nozzle of each zone on the spray beam is calculated. The pressure sensors of each zone set on the plate shape measuring roller correspond to the position distribution of the nozzle beam of each zone on the spray beam. The total flow rate given value L of the zone cooling is calculated. 总ref The percentage L of the flow rate given by each nozzle on the spray beam is determined by the given size ratio of the flow rate given by each nozzle in each area of the spray beam. ref [i], the edge area where the rolled coil is pressed against one side of the plate shape measuring roller is set as area i, and finally the flow rate is adjusted by the high-speed pulse control injection valve; The percentage of the given flow rate required to be sprayed by the nozzles in each zone on the spray beam L ref [i] and the given value of the total cooling flow of the zone L 总ref The following relationship exists: The edge area on the other side of the rolling mill coil pressed against the plate shape measuring roller is set as the i+n area.

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