Strip cooling device and method using cooling rolls

Abstract

This invention discloses a strip cooling device and method using cooling rollers. The device comprises: a cooling roller assembly (2), a circulating coolant system, a coolant circulation pipeline (4), a flow controller, and a temperature measuring instrument (3); the strip (1) travels around the cooling roller assembly; the coolant circulation pipeline includes several sub-pipelines; the cooling roller assembly is divided into several cooling roller groups, and each cooling roller (21) in each group is connected to a corresponding sub-pipeline; the coolant temperature in the first sub-pipeline is higher than the coolant temperature in the last sub-pipeline. The method comprises: determining a target flow regulating valve; the flow controller controlling the opening of the target flow regulating valve based on the difference ΔT between the strip temperature and the target temperature. The strip cooling device and method of this invention can achieve precise control of the strip temperature, creating favorable conditions for subsequent processes.

Description

Technical Field

[0001] This invention relates to a strip cooling technology, and more particularly to a strip cooling device and method that uses cooling rollers for cooling. Background Technology

[0002] In the steel production industry, strip steel is a very common product. In strip steel production lines, after continuous annealing, the surface of the strip steel needs to be coated. The coating process has certain requirements regarding the temperature of the strip steel being coated; it typically requires the strip steel to be at around room temperature. However, the temperature of the strip steel after continuous annealing and cooling is usually around 70-90 degrees Celsius, which clearly does not meet the process requirements. Therefore, the strip steel must be cooled before the coating process, and the temperature must be controlled within a narrow range to meet the process requirements.

[0003] Currently, there are many methods for cooling strip steel, such as high-speed gas jet cooling (e.g., high-hydrogen gas jet cooling), radiation cooling of radiant tubes, or water quenching with hot or cold water, etc. The characteristic of these cooling technologies is that they can achieve rapid cooling. However, the control precision of the final cooling temperature is not high, making it difficult to meet the process requirements for coating.

[0004] Chinese Patent (CN201120551020.X) discloses a sheet metal cooling device, including a frame, multiple lower cooling rollers mounted on the frame, and multiple upper cooling rollers positioned above the lower cooling rollers. The axes of the lower cooling rollers and the upper cooling rollers are aligned on a straight line, with the lower and upper cooling rollers evenly distributed and intersecting each other. This invention improves upon previous sheet metal cooling devices, increasing production speed, improving cooling efficiency, and reducing production costs. The multi-roller structure provides a leveling function for the sheet metal, resulting in a smoother surface without warping. The upper cooling rollers utilize a single motor for synchronous lifting, and each roller has an individual fine-tuning function to accommodate sheets of varying thicknesses. Each cooling roller has a unique water passage, further enhancing cooling performance and significantly reducing manufacturing costs and processing difficulty. However, the patented technology uses cooling rollers arranged above and below the running line of the plate to cool the plate. However, due to the small contact area between the plate and the cooling rollers, the cooling effect is not good. Since the contact area is changed by the pressure of the rollers, the plate is prone to warping, which affects the product quality.

[0005] In summary, the technical problem to be solved is that the traditional cooling method for strip steel is complex in terms of equipment and process, has low cooling accuracy, and the strip steel is unstable in state during the coating process, which affects the coating process of the strip steel. Summary of the Invention

[0006] The purpose of this invention is to provide a strip cooling device and method that uses cooling rollers for cooling, which enables precise control of strip temperature, thereby creating better conditions for subsequent processes.

[0007] To achieve the above-mentioned technical objectives, the present invention adopts the following technical solution:

[0008] A strip cooling device using cooling rollers for cooling, the strip cooling device comprising a cooling roller assembly, a circulating coolant equipment, a coolant circulation pipeline, a flow controller, and a temperature measuring instrument;

[0009] The cooling roller assembly is set on the moving path of the strip steel production line. The cooling roller assembly includes several cooling rollers, and the cooling rollers have coolant passages inside.

[0010] The coolant circulation pipeline includes several coolant circulation sub-pipelines, all of which are connected to the coolant circulation equipment; the cooling roller assembly is divided into several cooling roller groups, each cooling roller group corresponding to one coolant circulation sub-pipeline, and the coolant passage of the cooling roller in each cooling roller group is connected to the corresponding coolant circulation sub-pipeline.

[0011] Each coolant circulation branch is equipped with a flow regulating valve, which is controlled and connected to a flow controller;

[0012] The coolant temperature in the coolant circulation sub-pipeline corresponding to the cooling roller group that is ranked higher is higher than the coolant temperature in the coolant circulation sub-pipeline corresponding to the cooling roller group that is ranked lower.

[0013] The temperature measuring instrument is installed on the downstream side of the production line of the cooling roller assembly, and the temperature measuring instrument is electrically connected to the flow controller.

[0014] Furthermore, for each coolant circulation branch pipe and its corresponding cooling roller group in the coolant circulation pipeline, the coolant circulation branch pipe includes a main cooling pipe and one or more cooling branch pipes. The main cooling pipe is connected to the circulating coolant equipment. The coolant passage of the cooling roller in the cooling roller group is connected to the main cooling pipe through the cooling branch pipe. A flow regulating valve is provided in the cooling branch pipe, and the flow regulating valve is controlled and connected to the flow controller.

[0015] Furthermore, the coolant circulation pipeline includes two coolant circulation sub-pipelines, namely a first coolant circulation sub-pipeline and a second coolant circulation sub-pipeline; the cooling roller assembly is divided into two groups, namely a first cooling roller group and a second cooling roller group; the coolant passage of the cooling roller in the first cooling roller group is connected to the first coolant circulation sub-pipeline, and the coolant passage of the cooling roller in the second cooling roller group is connected to the second coolant circulation sub-pipeline; the first cooling roller group is ordered before the second cooling roller group, and the coolant temperature in the first coolant circulation sub-pipeline is higher than the coolant temperature in the second coolant circulation sub-pipeline.

[0016] Furthermore, the cooling roller assembly includes six cooling rollers, the first cooling roller group includes the three cooling rollers listed first in the cooling roller assembly, and the second cooling roller group includes the three cooling rollers listed last in the cooling roller assembly; the first coolant circulation branch line includes one cooling branch pipe, and the coolant passages of the three cooling rollers in the first cooling roller group are connected in series and then connected to the cooling main pipe of the first coolant circulation branch line through the cooling branch pipe; the second coolant circulation branch line includes three cooling branch pipes, and the coolant passages of the three cooling rollers in the second cooling roller group are respectively connected to the cooling main pipe of the second coolant circulation branch line through the three cooling branch pipes; for the one cooling branch pipe in the first coolant circulation branch line and the three cooling branch pipes in the second coolant circulation branch line, each cooling branch pipe is equipped with a flow regulating valve, and the flow regulating valve is controlled and connected to a flow controller.

[0017] Furthermore, the number of cooling rollers in the cooling roller assembly is even, and every two cooling rollers form a pair of cooling rollers. In the pair of cooling rollers, one cooling roller is a rear-mounted roller and the other is a front-mounted roller. The rear-mounted roller is located downstream of the front-mounted roller on the production line.

[0018] Furthermore, the flow regulating valve is an electromagnetic regulating valve.

[0019] Furthermore, the thermometer is an infrared thermometer.

[0020] Furthermore, the flow controller is a PID controller.

[0021] A strip cooling method based on the above-mentioned device, wherein the strip moves along the production line direction through the strip cooling device and passes through the strip cooling device, the strip moves around the cooling roller assembly of the strip cooling device;

[0022] The strip cooling method includes the following steps:

[0023] Step 1: The flow controller acquires the strip temperature T measured by the temperature measuring instrument. s;

[0024] Step 2, the flow controller will measure the strip temperature T s With the preset target temperature T t Subtraction, T s -T t =ΔT, thus obtaining the difference ΔT between the two;

[0025] Step 3: Select one or more flow control valves from the flow control valves of each coolant circulation branch line as the target flow control valve;

[0026] Step 4: When ΔT>0, the flow controller controls the target flow regulating valve to increase its opening; otherwise, the flow controller controls the target flow regulating valve to decrease its opening.

[0027] Furthermore, n-1 difference thresholds A are pre-set in the flow controller. i , i=1~n-1, and A i i+1 Where n is the number of all cooling branch pipes in the coolant circulation pipeline, and i is the sequence number of the difference threshold;

[0028] Step 3 further includes: determining the threshold range of |ΔT| based on the obtained ΔT, and then determining the target flow regulating valve based on the threshold range of |ΔT|, including:

[0029] Step 3.1: When 0 < |ΔT| ≤ A1, the flow regulating valve of the nth cooling branch pipe is determined as the target flow regulating valve;

[0030] Step 3.2, when A i <|ΔT|≤A i+1 When i = 1 to n-2, the flow regulating valves of the ni to nth cooling branch pipes are determined as the target flow regulating valves;

[0031] Step 3.3, when |ΔT|>A n-1 When the flow regulating valves of the first to nth cooling branch pipes are determined as the target flow regulating valves;

[0032] In the coolant circulation pipeline, the order of the first to nth cooling branch pipes is positively correlated with the order of the cooling rollers they are connected to.

[0033] ​In the strip cooling device of the present invention, the coolant circulation pipeline includes several coolant circulation sub-pipelines, which correspond to several cooling roller groups in the cooling roller assembly. Furthermore, the coolant temperature in the coolant circulation sub-pipeline corresponding to the cooling roller group that is ranked earlier is higher than the coolant temperature in the coolant circulation sub-pipeline corresponding to the cooling roller group that is ranked later, thereby forming a stepped cooling pattern of weaker front and stronger back in the cooling roller assembly, so as to accurately control the temperature of the strip exiting the cooling roller assembly.

[0034] In the cooling roll group, the coolant passage of the cooling roll is connected to the cooling main pipe through the cooling branch pipe. A flow regulating valve is installed in the cooling branch pipe. The flow regulating valve is controlled by a flow controller. The flow controller automatically controls the opening of the flow regulating valve, so that the coolant flow of each cooling branch pipe can be controlled individually, further improving the accuracy of strip temperature control.

[0035] In the strip cooling device of the present invention, in the cooling roller assembly, every two cooling rollers form a pair of cooling rollers, wherein one cooling roller is a rear-winding roller and the other cooling roller is a front-winding roller. During the process of the strip passing through the cooling roller assembly, when the strip passes through each pair of cooling rollers, the strip first passes around the rear-winding roller and then moves in the opposite direction of the production line, and then passes around the front-winding roller and moves in the direction of the production line. The contact area between the strip and the cooling roller is large, thereby improving the cooling efficiency of the cooling rollers on the strip.

[0036] In the strip cooling method of the present invention, the flow controller is based on the strip temperature T. s With target temperature T t The difference ΔT is used to automatically control the opening of the target flow regulating valve to regulate the flow rate of the coolant. The target flow regulating valve is determined based on the absolute value of ΔT, thereby achieving precise control of the strip temperature.

[0037] Compared with the prior art, the strip cooling device and method of the present invention have the following advantages: In the strip cooling device of the present invention, a stepped cooling pattern of weak front and strong rear is formed in the cooling roller assembly, and the flow controller can control the coolant flow of each cooling branch pipe individually by automatically controlling the opening of the flow regulating valve, thereby enabling precise control of the strip temperature; In the strip cooling method of the present invention, the flow controller adjusts the flow according to the strip temperature T. s With target temperature T t The difference ΔT is used to automatically control the opening of the target flow regulating valve, thereby achieving precise control of the strip temperature. The strip cooling device and method of the present invention have simple equipment processes and high precision in controlling the strip temperature, thus creating better process conditions for subsequent coating processes. Attached Figure Description

[0038] Figure 1 This is a schematic diagram of the strip cooling device of the present invention, which uses cooling rollers for cooling;

[0039] Figure 2 This is a flowchart of the strip cooling method of the present invention, which uses cooling rollers for cooling.

[0040] In the diagram: 1-Strip steel, 2-Cooling roller assembly, 21-Cooling roller, 3-Temperature measuring instrument, 4-Cooling fluid circulation pipeline, 41-First cooling fluid circulation branch pipeline, 42-Second cooling fluid circulation branch pipeline, 45-Cooling main pipe, 46-Cooling branch pipe, 48-Flow regulating valve. Detailed Implementation

[0041] The present invention will be further described below with reference to the accompanying drawings and specific embodiments:

[0042] The upstream and downstream sides mentioned in this article are based on the direction of the production line. The side closer to the preceding process of the production line is the upstream side, and the side closer to the following process of the production line is the downstream side.

[0043] This embodiment provides a strip cooling device that uses cooling rollers for cooling, which enables precise control of strip temperature.

[0044] See Figure 1 The strip cooling device of this embodiment includes a cooling roller assembly 2, a circulating coolant system, a coolant circulation pipeline 4, a flow controller, and a temperature measuring instrument 3. The cooling roller assembly 2 is positioned on the production line path of the strip 1, typically before coating equipment requiring specific surface temperatures for the strip, and after equipment such as annealing furnaces. The cooling roller assembly 2 includes six cooling rollers 21, each mounted on the production line frame via a sliding bearing seat. The central axis of each cooling roller 21 is parallel to the horizontal plane and perpendicular to the production line direction. In the cooling roller assembly 2, every two cooling rollers 21 form a cooling roller pair, such as... Figure 1 There are three pairs of cooling rollers arranged from left to right. In each pair, one cooling roller 21 is a rear-mounted roller, and the other is a front-mounted roller. With reference to the production line direction, the rear-mounted roller is located downstream of the front-mounted roller on the production line. Figure 1 Taking the cooling roller pair consisting of the first and second cooling rollers 21 on the left as an example, arrow A indicates the front roller, and arrow B indicates the rear roller. When the strip 1 moves along the production line direction and passes through the strip cooling device, the strip 1 winds around the cooling roller assembly 2. When passing through each pair of cooling rollers, the strip 1 first winds around the rear roller and then moves in the opposite direction of the production line, and then winds around the front roller and moves in the direction of the production line. During the process of winding around the cooling roller assembly 2, the strip 1 comes into contact with the cooling rollers 21, and the cooling rollers 21 can cool the strip 1.

[0045] In the cooling roller pair, the central axes of the rear roller and the front roller are not on the same horizontal plane; that is, the horizontal planes where their central axes lie are offset, so that the strip 1 can travel between the rear roller and the front roller. For example... Figure 1 As shown, in the first pair of cooling rollers through which strip 1 passes, the horizontal plane where the center axis of the rear roller is located is lower than the horizontal plane where the center axis of the front roller is located, while in the second pair of cooling rollers, the horizontal plane where the center axis of the rear roller is located is higher than the horizontal plane where the center axis of the front roller is located. In summary, in this embodiment, in the odd-numbered pairs of cooling rollers through which strip 1 passes, the horizontal plane where the center axis of the rear roller is located is lower than the horizontal plane where the center axis of the front roller is located, while in the even-numbered pairs of cooling rollers, the horizontal plane where the center axis of the rear roller is located is higher than the horizontal plane where the center axis of the front roller is located.

[0046] In other embodiments of the invention, the number of cooling rollers 21 included in the cooling roller assembly 2 can be determined as needed; the more cooling rollers 21 there are, the better the cooling effect on the strip 1. The number of cooling rollers 21 is preferably even, so that every two cooling rollers 21 form a cooling roller pair.

[0047] The temperature measuring instrument 3 is a non-contact infrared temperature measuring instrument. The temperature measuring instrument 3 is set on the downstream side of the production line of the cooling roller assembly 2. The temperature measuring instrument 3 is electrically connected to the flow controller (not shown in the figure). The temperature measuring end of the temperature measuring instrument 3 faces the strip steel 1 that moves out of the cooling roller assembly 2. The temperature measuring instrument 3 transmits the measured temperature of the strip steel 1 to the flow controller.

[0048] For each cooling roller 21 in the cooling roller assembly 2, the cooling roller 21 has a coolant passage inside, which is connected to the coolant circulation pipe 4. The coolant circulation pipe 4 is circulated in connection with the circulating coolant equipment (not shown in the figure). Thus, the coolant passage of the cooling roller 21 is circulated in connection with the circulating coolant equipment through the coolant circulation pipe 4. The coolant circulation pipe 4 is equipped with a flow regulating valve 48, which is controlled and connected to a flow controller (not shown in the figure). The flow controller can control the adjustment of the flow regulating valve 48 according to the temperature signal of the strip 1 measured by the thermometer 3, so as to control the flow rate of the coolant entering the cooling roller 21.

[0049] The coolant circulation pipeline 4 includes two coolant circulation sub-pipelines, namely a first coolant circulation sub-pipeline 41 and a second coolant circulation sub-pipeline 42. The coolant temperature in the first coolant circulation sub-pipeline 41 is higher than the coolant temperature in the second coolant circulation sub-pipeline 42. In this embodiment, the coolant used in the first coolant circulation sub-pipeline 41 is cooling water with an initial temperature of 20~35℃, while the coolant used in the second coolant circulation sub-pipeline 42 is chilled water with an initial temperature of -7~2℃. The cooling roller assembly 2 is divided into two cooling roller groups, namely a first cooling roller group and a second cooling roller group; the first cooling roller group includes the three cooling rollers 21 that are first in the order (in which the strip passes through) of the cooling roller assembly 2, such as... Figure 1 The three cooling rollers 21 without shadows are in the second cooling roller group, which includes the three cooling rollers 21 that are ordered later in the cooling roller assembly 2, such as... Figure 1 The three cooling rollers 21 are shaded, and the first cooling roller group is ordered before the second cooling roller group. That is, when the strip 1 moves along the production line to the strip cooling device, the strip 1 passes through the first cooling roller group first, and then passes through the second cooling roller group. The coolant passage of the cooling rollers 21 in the first cooling roller group is connected to the first coolant circulation branch pipe 41, and the coolant passage of the cooling rollers 21 in the second cooling roller group is connected to the second coolant circulation branch pipe 42.

[0050] Both coolant circulation branch lines include a main cooling pipe 45. The first coolant circulation branch line 41 also includes a cooling branch pipe 46, while the second coolant circulation branch line 42 includes three cooling branch pipes 46. The main cooling pipes 45 of the first and second coolant circulation branch lines 41 and 42 are independently connected to the circulating coolant equipment (not shown in the figure). The coolant passages of the three cooling rollers 21 of the first cooling roller group are connected in series and then circulate through a cooling branch pipe 46 of the first coolant circulation branch line 41 to the main cooling pipe 45 of the first coolant circulation branch line 41. The coolant passages of the three cooling rollers 21 of the second cooling roller group are respectively circulated through the three cooling branch pipes 46 of the second coolant circulation branch line 42 to the main cooling pipe 45 of the second coolant circulation branch line 42.

[0051] There are four cooling branch pipes 46 in total: one cooling branch pipe 46 in the first coolant circulation branch pipe 41 and three cooling branch pipes 46 in the second coolant circulation branch pipe 42. Each cooling branch pipe 46 is equipped with a flow regulating valve 48. The flow regulating valves 48 are connected to a flow controller, which can control the coolant flow rate of each cooling branch pipe 46 through the flow regulating valves 48.

[0052] In other embodiments of the present invention, the division of the cooling roller groups in the cooling roller assembly 2 and the setting of the corresponding coolant circulation sub-pipes can be determined according to specific circumstances. In general:

[0053] The coolant circulation pipeline 4 may include several coolant circulation sub-pipelines. Correspondingly, the cooling roller assembly 2 is divided into several cooling roller groups, each cooling roller group corresponding to one coolant circulation sub-pipeline. Each of the several coolant circulation sub-pipelines is independently connected to the coolant circulation equipment, and the coolant passage of the cooling roller 21 in each cooling roller group is connected to the corresponding coolant circulation sub-pipeline.

[0054] The coolant temperature in the cooling fluid circulation sub-pipeline corresponding to the earlier-ordered cooling roller group is higher than the coolant temperature in the cooling fluid circulation sub-pipeline corresponding to the later-ordered cooling roller group. In other words, the coolant temperature in the cooling fluid circulation sub-pipeline corresponding to the several cooling roller groups decreases from high to low as the cooling roller groups are ordered (in the order in which the strip passes through).

[0055] For each coolant circulation branch pipe and its corresponding cooling roller group in the coolant circulation pipeline 4, the coolant circulation branch pipe includes a main cooling pipe 45 and one or more cooling branch pipes 46. The main cooling pipe 45 is circulatedly connected to the circulating coolant equipment. The coolant passage of the cooling roller 21 in the cooling roller group is circulatedly connected to the main cooling pipe 45 through the cooling branch pipe 46. A flow regulating valve 48 is provided in the cooling branch pipe 46. The flow regulating valve 48 is controlled and connected to a flow controller. The flow controller regulates the coolant flow rate in the cooling branch pipe 46 through the flow regulating valve 48.

[0056] It should be noted that the order of the cooling roller groups or cooling rollers 21 refers to the sequence in which the strip 1 passes through the cooling roller groups or cooling rollers 21 along the production line. When the strip 1 moves along the production line, the cooling roller groups or cooling rollers 21 that the strip 1 passes through first are listed earlier, and the cooling roller groups or cooling rollers 21 that the strip 1 passes through later are listed later. It is important to note that the order described here is based on the order in which the strip 1 passes through, not the overall sequence on the production line. For example, Figure 1 Although the leftmost two cooling rollers are located downstream of the cooling roller indicated by arrow B, the strip 1 passes through the cooling roller indicated by arrow B before passing through the cooling roller indicated by arrow A. Therefore, the order of the cooling rollers indicated by arrow B is earlier than that of the cooling roller indicated by arrow A.

[0057] In this embodiment, the flow controller is a PID controller. The PID controller (Proportional-Integral-Derivative controller) is a prior art flow controller widely used in various fields. A PID controller consists of a proportional unit (P), an integral unit (I), and a derivative unit (D). The PID controller compares the collected data with a reference value and then uses this difference to calculate a new input value. The purpose of this new input value is to allow the system data to reach or remain at the reference value.

[0058] In this embodiment, the flow regulating valve 48 is an electromagnetic regulating valve. However, in other embodiments, other types of flow regulating valves 48, such as pneumatic regulating valves, may also be used.

[0059] In the strip cooling device of this embodiment, the coolant circulation pipeline 4 includes two coolant circulation sub-pipelines. In the two sub-pipelines, the coolant temperature in the first coolant circulation sub-pipeline 41 is higher than the coolant temperature in the second coolant circulation sub-pipeline 42. In the cooling roller assembly 2, the three cooling rollers 21 of the first cooling roller group are connected to the first coolant circulation sub-pipeline 41, while the three cooling rollers 21 of the second cooling roller group are connected to the cooling main pipe 45 of the second coolant circulation sub-pipeline 42. Thus, a stepped cooling pattern with weak front and strong back is formed in the cooling roller assembly 2, so as to accurately control the temperature of the strip 1 exiting the cooling roller assembly 2. In addition, the three cooling rollers 21 of the first cooling roller group are connected to the cooling main pipe 45 of the first coolant circulation branch pipe 41 through a cooling branch pipe 46, and the three cooling rollers 21 of the second cooling roller group are respectively connected to the cooling main pipe 45 of the second coolant circulation branch pipe 42 through three cooling branch pipes 46. A flow regulating valve 48 is installed on each cooling branch pipe 46, for a total of four flow regulating valves 48. The flow regulating valves 48 are controlled and connected to a flow controller, which automatically controls the opening of the flow regulating valves 48, thereby allowing individual control of the coolant flow of each cooling branch pipe 46, further improving the accuracy of the temperature control of the strip steel 1.

[0060] In the strip cooling device of this embodiment, in the cooling roller assembly 2, every two cooling rollers 21 form a pair of cooling rollers. One cooling roller 21 is a rear-winding roller, and the other cooling roller 21 is a front-winding roller. When the strip 1 passes through the cooling roller assembly 2, the strip 1 first passes around the rear-winding roller and moves in the opposite direction of the production line. Then the strip 1 passes around the front-winding roller and moves in the direction of the production line. The contact area between the strip 1 and the cooling roller 21 is large, thereby improving the cooling efficiency of the cooling roller 21 on the strip 1.

[0061] See Figure 1 and Figure 2 This embodiment also provides a strip cooling method based on the above-mentioned strip cooling device, which uses cooling rollers for cooling. This strip cooling method, based on the strip cooling device, can achieve precise control of strip temperature.

[0062] Specifically, n-1 difference thresholds A are pre-set in the flow controller. i , i=1~n-1, and A i i+1 , where n is the number of all cooling branch pipes in the coolant circulation pipeline, and i is the sorting number of the difference threshold.

[0063] See Figure 2 The strip cooling method includes the following steps:

[0064] Step 1: The flow controller acquires the strip temperature T measured by the temperature measuring instrument 3. s .

[0065] Step 2, the flow controller will measure the strip temperature T s With the preset target temperature T t Subtraction, T s -T t =ΔT, thus obtaining the difference ΔT between the two.

[0066] Step 3: Select one or more flow control valves as target flow control valves from the flow control valves 48 of each coolant circulation branch line; specifically, first determine the threshold range of the absolute value |ΔT| based on the obtained ΔT, and then determine the target flow control valve based on the threshold range of |ΔT|, including:

[0067] Step 3.1: When 0 < |ΔT| ≤ A1, the flow regulating valve 48 of the last nth cooling branch pipe 46 is determined as the target flow regulating valve.

[0068] Step 3.2, when A i <|ΔT|≤A i+1 When i = 1 to n-2, the flow regulating valve 48 of the ni to nth cooling branch pipe 46 is determined as the target flow regulating valve.

[0069] Step 3.3, when |ΔT|>A n-1 At that time, the flow regulating valve 48 of the first to nth cooling branch pipes 46 is determined as the target flow regulating valve.

[0070] ​Step 4: When ΔT>0, the flow controller controls the target flow regulating valve to increase its opening to increase the flow rate of the coolant; otherwise, the flow controller controls the target flow regulating valve to decrease its opening to increase the flow rate of the coolant. The flow controller only controls the target flow regulating valve for adjustment, while the openings of other flow regulating valves 48 remain unchanged.

[0071] It should be noted that, among all the cooling branch pipes 46 in the coolant circulation pipeline 4, the order of the first to the nth cooling branch pipe 46 is positively correlated with the order of the cooling rollers 21 to which it is connected. Specifically, the earlier the cooling roller 21 to which the cooling branch pipe 46 is connected is, the earlier the cooling branch pipe 46 is in the overall sequence; conversely, the later the cooling roller 21 to which the cooling branch pipe 46 is connected is, the later the cooling branch pipe 46 is in the overall sequence.

[0072] The strip cooling method of this embodiment is used to cool strip 1, and the flow controller is based on the strip temperature T. s With target temperature T t The difference ΔT is used to automatically control the opening of the target flow regulating valve to regulate the flow rate of the coolant. The target flow regulating valve is determined based on the absolute value of ΔT, thereby achieving precise control of the temperature of strip 1.

[0073] The following is an embodiment of the strip cooling method:

[0074] If the number of cooling branch pipes 46 in the coolant circulation pipeline 4 is n=4, then 4-1=3 difference thresholds need to be set in advance, namely A1, A2 and A3, where A1=3℃, A2=5℃ and A3=8℃.

[0075] 1) The flow controller acquires the strip temperature T measured by the temperature measuring instrument 3. s .

[0076] 2) The flow controller will measure the strip temperature T s With the preset target temperature T t Subtraction, T s -T t =ΔT, thus obtaining the difference ΔT between the two.

[0077] 3) Based on the obtained ΔT, determine the threshold range within which |ΔT| lies, and then determine the target flow control valve based on the threshold range within which |ΔT| lies, including:

[0078] 3.1) When 0 < |ΔT| ≤ A1, that is, when 0 < |ΔT| ≤ 3, the flow regulating valve 48 of the fourth cooling branch pipe 46 is determined as the target flow regulating valve.

[0079] 3.2) When A1 < |ΔT| ≤ A2, that is, when 3 < |ΔT| ≤ 5, the flow regulating valves 48 of the 3rd and 4th cooling branch pipes 46 are determined as the target flow regulating valves; while when A2 < |ΔT| ≤ A3, that is, when 5 < |ΔT| ≤ 8, the flow regulating valves 48 of the 2nd to 4th cooling branch pipes 46 are determined as the target flow regulating valves.

[0080] 3.3) When |ΔT|>A3, that is, when |ΔT|>8, all the flow regulating valves 48 of the first to fourth cooling branch pipes 46 are determined as target flow regulating valves.

[0081] 4) When ΔT>0, the flow controller controls the target flow regulating valve to increase its opening; otherwise, the flow controller controls the target flow regulating valve to decrease its opening. The flow controller only controls the target flow regulating valve to adjust, while the openings of other flow regulating valves 48 remain unchanged.

[0082] The above are merely preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Therefore, any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A strip cooling device employing a cooling roll, characterized by: The strip steel cooling device comprises a cooling roller combination (2), a circulating cooling liquid device, a cooling liquid circulating pipeline (4), a flow controller and a temperature measuring instrument (3); The cooling roller combination (2) is arranged on a moving path of a production line of the strip steel (1), and the cooling roller combination (2) comprises a plurality of cooling rollers (21); the cooling roller (21) is internally provided with a cooling liquid passage; The cooling liquid circulating pipeline (4) comprises a plurality of cooling liquid circulating sub-pipelines, and the plurality of cooling liquid circulating sub-pipelines are in communication with the circulating cooling liquid device; the cooling roller combination (2) is divided into a plurality of cooling roller groups, each cooling roller group corresponds to one cooling liquid circulating sub-pipeline, and the cooling liquid passage of the cooling roller (21) in each cooling roller group is connected to the corresponding cooling liquid circulating sub-pipeline; A flow regulating valve (48) is arranged in each cooling liquid circulating sub-pipeline, and the flow regulating valve (48) is connected to the flow controller in an electrically controlled mode; The cooling liquid temperature in the cooling liquid circulating sub-pipeline corresponding to a cooling roller group arranged in front is higher than the cooling liquid temperature in the cooling liquid circulating sub-pipeline corresponding to a cooling roller group arranged at the rear; The temperature measuring instrument (3) is arranged on a downstream side of the cooling roller combination (2) in the production line, and the temperature measuring instrument (3) is electrically connected to the flow controller in a signal mode; For each cooling liquid circulating sub-pipeline in the cooling liquid circulating pipeline (4) and the corresponding cooling roller group, the cooling liquid circulating sub-pipeline comprises one cooling main pipe (45) and one or more cooling branch pipes (46), the cooling main pipe (45) is in communication with the circulating cooling liquid device, the cooling liquid passage of the cooling roller (21) in the cooling roller group is connected to the cooling main pipe (45) through the cooling branch pipe (46), and the flow regulating valve (48) is arranged in the cooling branch pipe (46) and connected to the flow controller in an electrically controlled mode; The cooling liquid circulating pipeline (4) comprises two cooling liquid circulating sub-pipelines, namely a first cooling liquid circulating sub-pipeline (41) and a second cooling liquid circulating sub-pipeline (42); the cooling roller combination (2) is divided into two cooling roller groups, namely a first cooling roller group and a second cooling roller group; the cooling liquid passage of the cooling roller (21) in the first cooling roller group is connected to the first cooling liquid circulating sub-pipeline (41), and the cooling liquid passage of the cooling roller (21) in the second cooling roller group is connected to the second cooling liquid circulating sub-pipeline (42); The first cooling roller group is arranged in front of the second cooling roller group, and the cooling liquid temperature in the first cooling liquid circulating sub-pipeline (41) is higher than the cooling liquid temperature in the second cooling liquid circulating sub-pipeline (42).

2. The strip cooling device employing a cooling roll for cooling according to claim 1, characterized in that: The cooling roller combination (2) comprises six cooling rollers (21), the first cooling roller group comprises three cooling rollers (21) arranged in front in the cooling roller combination (2), and the second cooling roller group comprises three cooling rollers (21) arranged at the rear in the cooling roller combination (2). The cooling branch pipe (46) included in the first cooling liquid circulation sub-pipeline (41) is one, and the cooling liquid passages of the three cooling rollers (21) of the first cooling roller group are connected in series and communicated with the cooling main pipe (45) of the first cooling liquid circulation sub-pipeline (41) through the cooling branch pipe (46); the cooling branch pipe (46) included in the second cooling liquid circulation sub-pipeline (42) is three, and the cooling liquid passages of the three cooling rollers (21) of the second cooling roller group are respectively communicated with the cooling main pipe (45) of the second cooling liquid circulation sub-pipeline (42) through the three cooling branch pipes (46); For the one cooling branch pipe (46) in the first cooling liquid circulation sub-pipeline (41) and the three cooling branch pipes (46) in the second cooling liquid circulation sub-pipeline (42), a flow regulating valve (48) is arranged on each cooling branch pipe (46), and the flow regulating valve (48) is controlled and connected to the flow controller.

3. The strip cooling device employing a cooling roll for cooling according to claim 1, characterized in that: The number of cooling rollers (21) in the cooling roller combination (2) is even, and each two cooling rollers (21) form a cooling roller pair, in which one cooling roller (21) is a rear roller and the other cooling roller (21) is a front roller, and the rear roller is located on the downstream side of the front roller in the production line.

4. The strip cooling device employing a cooling roll for cooling according to claim 1, characterized by: The flow regulating valve (48) is an electromagnetic regulating valve.

5. The strip cooling device employing a cooling roll for cooling according to claim 1, characterized by: The temperature measuring instrument (3) is an infrared temperature measuring instrument.

6. The strip cooling device employing a cooling roll for cooling according to claim 1, characterized by: The flow controller is a PID controller.

7. A strip cooling method using a cooling roll in a strip cooling device according to claim 1, characterized by: When the strip steel (1) moves along the production line direction through the strip steel cooling device, the strip steel (1) passes through the cooling roller combination (2) of the strip steel cooling device; The strip steel cooling method comprises the following steps: Step 1, the flow controller acquires the strip temperature T measured by the temperature measuring instrument (3) s ; Step 2, the flow controller will measure the strip temperature T s Subtract the preset target temperature T t , T s -T t = ΔT, the difference between the two is ΔT; Step 3: determining one or more flow regulating valves as target flow regulating valves in the flow regulating valves (48) of each cooling liquid circulation sub-pipeline; Step 4: when ΔT>0, the flow controller controls the target flow regulating valve to increase the opening degree, otherwise, the flow controller controls the target flow regulating valve to decrease the opening degree.

8. The strip cooling method employing a cooling roll for cooling according to claim 7, characterized in that: In the strip steel cooling device, for each cooling liquid circulation sub-pipeline and the corresponding cooling roller group in the cooling liquid circulation pipeline (4), the cooling liquid circulation sub-pipeline includes one cooling main pipe (45) and one or more cooling branch pipes (46), the cooling main pipe (45) is communicated with the circulating cooling liquid equipment, the cooling liquid passages of the cooling rollers (21) in the cooling roller group are communicated with the cooling main pipe (45) through the cooling branch pipes (46), and a flow regulating valve (48) is arranged in the cooling branch pipe (46), and the flow regulating valve (48) is controlled and connected to the flow controller; n-1 difference threshold values A are preset in the flow controller i , i = 1~n-1, and A i <A i+1 wherein n is the number of all cooling branches in the cooling liquid circulation pipeline, and i is the serial number of the difference threshold value. The step 3 further comprises: judging the threshold range in which |ΔT| is located according to the obtained ΔT, and then determining the target flow regulating valve according to the threshold range in which |ΔT| is located, which comprises: Step 3.1: when 0<|ΔT|≤A1, the flow regulating valve (48) of the nth cooling branch pipe (46) is determined as the target flow regulating valve; Step 3.2, when A i <|ΔT|≤A i+1 , and when i = 1~n-2, the flow regulating valve (48) of the n-i-th to n-th cooling branch pipe (46) is determined as the target flow regulating valve; Step 3.3, when |ΔT| > A n-1 the flow regulating valves (48) of the first to nth cooling branch pipes (46) are determined as target flow regulating valves; In all the cooling branch pipes (46) in the cooling liquid circulation pipeline (4), the first to nth cooling branch pipes (46) are positively correlated with the sorting of the cooling rollers (21) connected thereto.

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