Cooling device and method for forming stable temperature gradient by large-scale differential temperature rolling

Abstract

The application discloses a cooling device and method for forming stable temperature gradient by large cylinder segment differential temperature rolling, and relates to the technical field of rolling metallurgy process. The flow of cooling water can be automatically adjusted according to the temperature distribution in the thickness direction of the cylinder segment and the flow fluctuation in the pipeline, thereby reducing the axial temperature difference of the cylinder segment and the risk of surface cracking, and the cooling water can be recycled without filtration. The cooling device comprises a temperature acquisition device, a control unit, an upper cooling support device and a lower cooling support device; the upper cooling support device and the lower cooling support device are respectively supported on the inner and outer wall surfaces of the cylinder segment; the upper cooling support device comprises an upper cooling roller and a cooling system symmetrically arranged on both sides of the upper cooling roller; the upper cooling roller comprises a shell, a reflux cylinder and a center support plate; the lower cooling support device is the same in structure as the upper cooling device; the cooling system comprises a water inlet pipeline, a water return pipeline, a water pump, a water tank and a plurality of spraying assemblies. The application also provides a cooling method based on the device.

Description

Technical Field

[0001] This application relates to the field of steel rolling metallurgical process technology, and in particular to a cooling device and method for forming a stable temperature gradient in large-scale differential temperature rolling. Background Technology

[0002] Large cylindrical sections are core basic components in the petrochemical, nuclear power, and energy sectors, significantly impacting the stable operation of equipment. They often operate in harsh environments such as high temperature and high pressure, thus requiring excellent mechanical properties. With the continuous development of my country's industry, the demand for large cylindrical sections is gradually increasing. As ultra-large and thick components, large cylindrical sections can reach diameters of up to 8 meters, axial widths of up to 3 meters, and thicknesses of up to 0.5 meters, weighing up to hundreds of tons.

[0003] Differential temperature rolling (DTC) is a special rolling process that cools the surface of a workpiece to harden it while maintaining a high-temperature, softened state in the core. This creates a temperature gradient along the workpiece's thickness, causing variations in deformation resistance at different thicknesses. During rolling, deformation penetrates towards the core. DTC can address the challenges of large cylindrical sections with large radial thicknesses, where uneven plastic deformation during rolling can lead to significant surface deformation and minimal core deformation. This results in coarse grains and even cracks in the core structure, ultimately rendering the cylindrical section unusable.

[0004] Existing annular spray assembly has a complex structure and is susceptible to uneven cooling of the cylinder surface due to gravity. Its cooling capacity cannot be automatically adjusted, making it unsuitable for situations where cylinder thickness changes during rolling and cooling capacity requirements change accordingly. It also makes it difficult to ensure uniform internal structure of the cylinder. Furthermore, direct spraying of cooling water onto the cylinder surface is prone to contamination, consumes a large amount of water, and increases the risk of surface cracking. Summary of the Invention

[0005] The embodiments of this application provide a cooling device and method for forming a stable temperature gradient in differential temperature rolling of large cylinder sections. Under the premise that the flow rate of cooling water can be automatically adjusted according to the temperature distribution in the thickness direction of the cylinder section and the flow fluctuation in the pipeline during the rolling process, not only is the axial temperature difference of the cylinder section reduced by bidirectional water inlet, but also the risk of surface cracking of the cylinder section is reduced because the cooling water does not directly contact the cylinder section. At the same time, the cooling water can be directly recycled without filtration.

[0006] To achieve the above objectives, embodiments of this application provide a cooling device for forming a stable temperature gradient in large-scale differential temperature rolling, including a temperature acquisition device, a control unit, an upper cooling support device, and a lower cooling support device; the upper and lower cooling support devices are respectively supported on the inner and outer walls of the roll section; the upper cooling support device includes an upper cooling roller and a cooling system symmetrically arranged on both sides of the upper cooling roller; the upper cooling roller includes a shell, a return cylinder, and a central support plate; the return cylinder is sleeved inside the shell, and a return water annular cavity is formed between the shell and the return cylinder; the central support plate divides both the return water annular cavity and the inner cavity of the return cylinder into two parts; the lower cooling support device includes a lower cooling roller and a cooling system symmetrically arranged on both sides of the upper cooling roller; the lower cooling roller... The structure is the same as the upper cooling roller, but the diameter of the lower cooling roller is larger than that of the upper cooling roller. The cooling system includes an inlet water pipe, a return water pipe, a water pump, a water tank, and multiple spray components. The spray components, inlet water pipe, water pump, and water tank are connected in sequence. The spray components can spray and cool the inner wall surface of the shell. The return water annular cavity is connected to the water tank through the return water pipe. A flow regulating valve is provided on the inlet water pipe. The temperature acquisition device can collect the temperature of the inner and outer wall surfaces, 1 / 4 thickness, and center of the cylinder section in real time. The temperature acquisition device and the flow regulating valve are both communicatively connected to the control unit. The control unit can generate a cylinder section temperature distribution curve based on the temperature value collected by the temperature acquisition device and adjust the opening of the flow regulating valve according to the cylinder section temperature distribution curve.

[0007] Furthermore, the reflux cylinder includes a reflux cylinder body and side support plates disposed at both ends of the reflux cylinder body; the side support plates are annular; the outer circular surface of the side support plates is connected to the inner wall of the shell, and the inner hole is connected to the outer wall of the water inlet pipe; the shell has openings at both ends; the outlet of the water return pipe is connected to the opening of the shell; the water return pipe is sleeved on the outside of the water inlet pipe; the side support plates are provided with flow holes, and the water return annular cavity is connected to the water return pipe through the flow holes; a one-way valve is provided in the flow holes.

[0008] Furthermore, both the inner wall of the shell and the outer wall of the reflux cylinder are sloping surfaces that are higher in the middle and lower on both sides.

[0009] Furthermore, the water inlet pipe is connected to the side of the central support plate; the water inlet pipe includes a rotating water inlet pipe and a fixed water inlet pipe; the return water pipe includes a rotating return water pipe and a fixed return water pipe; the cooling system also includes a converter; the outer ring of the converter is connected to the rotating return water pipe and the fixed return water pipe at both ends, and the inner ring is connected to the rotating water inlet pipe and the fixed water inlet pipe at both ends.

[0010] Furthermore, multiple spray assemblies are evenly layered along the axial direction of the water inlet pipe; spray assemblies located in the same layer are evenly distributed along the circumference of the water inlet pipe; each spray assembly includes a nozzle and a spray pipe disposed between the nozzle and the water inlet pipe; the nozzle is located within the return water ring cavity.

[0011] Furthermore, the nozzle is a conical nozzle, and on the plane of maximum water flow, the water flows sprayed from two adjacent nozzles overlap.

[0012] Furthermore, the central support plate includes a circular support plate and an outer ring plate disposed around the outer periphery of the circular support plate; the outer ring plate is connected to the inner wall of the shell; the thickness of the outer ring plate is less than the thickness of the circular support plate.

[0013] Furthermore, a flow meter is installed on the water inlet pipe, and the flow meter is also communicatively connected to the control unit; the control unit can fine-tune the opening of the flow regulating valve based on the detected value of the flow meter.

[0014] Furthermore, the temperature acquisition device includes two surface temperature sensors, two temperature sensors at 1 / 4 thickness, and a center temperature sensor; the two surface temperature sensors are respectively disposed on the inner and outer surfaces of the cylinder section; the temperature sensors at 1 / 4 thickness and the center temperature sensor are both disposed on the end face of the cylinder section.

[0015] On the other hand, this application embodiment also provides a cooling method based on the cooling device for forming a stable temperature gradient in the above-mentioned large-scale differential temperature rolling of the cylinder section, including the following steps: S1, before the start of rolling, the temperature acquisition device collects the temperature values ​​of the inner and outer walls, 1 / 4 thickness and center of the cylinder section in real time during idling; the control unit generates a temperature distribution curve based on the received temperature values; S2, the control unit adjusts the initial opening of the flow regulating valve according to the temperature distribution curve, and the spray assembly sprays water to cool the inner wall of the upper or lower cooling roller shell; under the combined action of cooling by the upper or lower cooling roller and air cooling, a preset temperature gradient is formed on the cylinder section; S3, after the start of rolling, the control unit continues to receive the temperature values ​​detected by the temperature acquisition device, and adjusts the opening of the flow regulating valve according to the temperature values ​​to maintain the stability of the cylinder section temperature gradient.

[0016] This application has the following advantages over the prior art: 1. This application achieves uniform axial temperature of the upper and lower cooling rollers by symmetrically arranging cooling systems on both sides of the upper and lower cooling rollers during operation, allowing both cooling systems to simultaneously receive and drain water. Since the upper and lower cooling rollers are in contact with the inner and outer walls of the cylinder section, uniform cooling in the axial direction of the cylinder section is achieved.

[0017] 2. This application involves installing a temperature acquisition device on the cylinder section to collect the temperature of the inner and outer walls, 1 / 4 thickness, and center in real time. A flow meter and flow regulating valve are installed on the inlet water pipe. The temperature signal from the temperature acquisition device during rolling is used to adjust the opening of the flow regulating valve, forming a feedback regulation loop. Furthermore, the flow meter detects the cooling water flow rate at the inlet pipe to correct the opening of the flow regulating valve, overcoming interference from flow fluctuations and forming a feedforward regulation loop. Through the combined action of the feedforward and feedback regulation loops, the temperature gradient of the cylinder section is maintained stably, overcoming the problem that existing cooling technologies cannot adapt to changes in cylinder thickness.

[0018] 3. This application cools the surface of the cylinder section by contacting the upper and lower cooling rollers with the cylinder section. The cooling water is not contaminated during use and can be directly recycled without filtration. This overcomes the problems that direct contact between the cooling water and the cylinder section surface can easily cause cracking of the cylinder section surface, and that the cooling water consumption is large and cannot be directly recycled. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a schematic diagram of the cooling device for forming a stable temperature gradient during differential temperature rolling of large cylindrical sections, as described in an embodiment of this application. Figure 2 This is a schematic diagram of the upper cooling support device in the cooling device for forming a stable temperature gradient during differential temperature rolling of large cylindrical sections, as described in an embodiment of this application. Figure 3 This is a schematic diagram of the arrangement of one-way valves in a cooling device for forming a stable temperature gradient during differential temperature rolling of large cylindrical sections, as described in an embodiment of this application. Figure 4 This is a schematic diagram of the arrangement of a single-layer spray assembly in a cooling device for forming a stable temperature gradient during differential temperature rolling of large cylindrical sections, as described in an embodiment of this application. Figure 5 This is a schematic diagram of the axial arrangement of different layers of spray components in a cooling device for forming a stable temperature gradient during differential temperature rolling of large cylindrical sections, as described in an embodiment of this application. Figure 6 This is a schematic diagram of the cooling system in the cooling device for forming a stable temperature gradient during differential temperature rolling of large cylindrical sections, as described in this application embodiment. Detailed Implementation

[0021] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0022] In the description of this application, it should be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0023] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation", "connection" and "joining" should be interpreted broadly, for example, as fixed connection, detachable connection, or integral connection; those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0024] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, unless otherwise stated, "a plurality of" means two or more.

[0025] Reference Figure 1 This application provides a cooling device for forming a stable temperature gradient in large-scale differential temperature rolling, including an upper cooling support device 1, a lower cooling support device 2, a temperature acquisition device 3, and a control unit 4.

[0026] The upper cooling support device 1 and the lower cooling support device 2 are respectively supported on the inner and outer walls of the cylinder section 5 and are located between the two sets of support rollers 6.

[0027] Reference Figures 2 to 6The upper cooling support device 1 includes an upper cooling roller 11 and a cooling system 12 symmetrically arranged on both sides of the upper cooling roller 11. The upper cooling roller 11 includes a shell 111, a return cylinder 112, and a central support plate 113. The return cylinder 112 is fitted inside the shell 111, forming a return water annular cavity 114 between the shell 111 and the return cylinder 112. The central support plate 113 divides both the return water annular cavity 114 and the inner cavity of the return cylinder 112 into two parts of equal volume. To increase the contact heat exchange area between the upper cooling roller 11 and the cylinder section 5 under the same pressure, the size of the upper cooling roller 11 should be larger than that of a conventional cooling roller. Since the upper cooling roller 11 is hollow inside, to maintain the strength requirements of the cylinder section 5 during differential temperature rolling, the material of the upper cooling roller 11 should be a material with excellent mechanical properties.

[0028] The lower cooling support device 2 includes a lower cooling roller and a cooling system 12 symmetrically arranged on both sides of the upper cooling roller. Since the structure of the lower cooling roller is the same as that of the upper cooling roller 11, the only difference between the two is that the diameter of the lower cooling roller is larger than that of the upper cooling roller. Therefore, the structure of the lower cooling roller will not be described in detail here.

[0029] The cooling system 12 includes an inlet water pipe 121, a return water pipe 122, a water pump 123, a water tank 124, and multiple spray components 125. The spray components 125, inlet water pipe 121, water pump 123, and water tank 124 are connected sequentially. The spray components 125 can spray cooling onto the inner wall surface of the housing 111. The return water annular cavity 114 is connected to the water tank 124 via the return water pipe 122. Thus, the spray components 125 can spray cooling onto the inner wall surface of the upper cooling roller 11 from within, causing heat transfer from the outer wall surface of the upper cooling roller 11 inwards, creating a low temperature on the outer wall surface. Before rolling, a preset temperature gradient is formed on the cylinder section 5 through heat exchange between the upper cooling roller 11 and the inner and outer walls of the cylinder section 5, as well as air cooling. During rolling, the temperature gradient of the cylinder section 5 is maintained stable by the cooling effect of the upper cooling roller 11, regulated by the control system.

[0030] Specifically, the housing 111 is a hollow cylinder sealed at both ends, and each end of the housing 111 has an opening 115 at its center that connects to the return water pipe 122.

[0031] The reflux cylinder 112 includes a reflux cylinder body 116 and side support plates 117 located at both ends of the reflux cylinder body 116. The side support plates 117 are annular. The outer circular surface of the side support plates 117 is connected to the inner wall of the shell 111, and the inner hole is connected to the water inlet pipe 121. Both the inner wall surface of the shell 111 and the outer wall surface of the reflux cylinder body 116 are inclined surfaces with a higher center and lower sides, so that the cooling water can quickly flow to both sides and be discharged after contacting and exchanging heat with the inner wall surface. It should be noted that a certain slope can also be provided in the middle area of ​​the inner wall surface of the shell 111 and the outer wall surface of the reflux cylinder body 116, and the slopes of the two are the same. Thus, the distance between them gradually increases from the center to both sides, which facilitates the cooling water to quickly flow to both sides and be discharged after contacting and exchanging heat with the inner wall surface. At the same time, since the outer side of the inner wall surface of the shell 111 remains horizontal, the drainage is smoother, which can prevent the cooling water from accumulating at this point and reduce the risk of corrosion.

[0032] Reference Figure 3 The return cylinder 112 is also provided with baffles 118 that extend axially and are evenly distributed circumferentially. This structure can prevent the cooling water from flowing downward under the action of gravity during rotation and affecting the discharge of the cooling water.

[0033] The thickness of the central support plate 113 and the side support plate 117 needs to be determined by stress calculation to ensure that the upper cooling roller 11 meets the usage conditions. The side support plate 117, the central support plate 113, the housing 111, and the return cylinder 112 are all fixedly connected by welded structures.

[0034] Reference Figure 2 The central support plate 113 includes a circular support plate 1131 and an outer ring plate 1132 disposed on the outer periphery of the circular support plate. The outer ring plate 1132 is connected to the inner wall of the housing 111. In order to increase the contact area between the water sprayed by the spray assembly 125 and the inner wall surface of the upper cooling roller 11 and enhance the heat exchange effect, the thickness of the outer ring plate 1132 in this application is less than the thickness of the circular support plate 1131.

[0035] One end of the inlet pipe 121 extends into the return cylinder 112 and is connected to the side of the central support plate 113, while the other end is connected to the water tank 124 via the water pump 123. The cross-sectional area of ​​the inlet pipe 121 is smaller than the cross-sectional area of ​​the return ring pipe 122 minus the inlet pipe 121, so that the cooling water can be discharged smoothly.

[0036] A water tank 124 has an inlet flange 1241 and a drain flange 1242 installed on one side to ensure a certain water level is maintained in the tank 124 and to allow for water filling or emptying at the start or end of use. The other side of the tank 124 is connected to a water pump 123. The water pump 123 is preferably a common multistage centrifugal pump.

[0037] Reference Figure 2 and Figure 4The spray assembly 125 includes a nozzle and a spray pipe 128 disposed between the nozzle 127 and the water inlet pipe 121. The nozzle 127 is located within the return water annular cavity 114 and faces the inner wall of the housing 111. Multiple spray assemblies 125 are evenly layered along the axial direction of the water inlet pipe 121. Spray assemblies 125 in the same layer are evenly distributed circumferentially along the water inlet pipe 121. The included angle between two adjacent spray assemblies 125 is related to the position of the baffle 118 within the return cylinder 112, and both are determined by the diameters of the water inlet pipe 121 and the spray pipe 128. Preferably, the included angle is 30° to 45°. The nozzle 127 and the spray pipe 128 are welded together. The nozzle 127 is a conical nozzle, and on the plane of maximum water flow, the water streams sprayed from two adjacent nozzles 127 overlap to ensure sufficient cooling of the wall surface and avoid uncooled areas.

[0038] The inlet pipe 121 is equipped with a flow regulating valve 126 and a flow meter 129. The flow meter 129 can collect the flow rate of the cooling water in the inlet pipe 121, and the flow regulating valve 126 can regulate the flow rate of the cooling water in the inlet pipe 121.

[0039] The return water pipe 122 is sleeved outside the inlet water pipe 121. One end of the return water pipe 122 is connected to the opening 115 of the shell 111, and the other end is connected to the water tank 124. A flow passage area is provided between the side support plate 117 and the inner walls at both ends of the shell 111. The side support plate 117 has multiple flow passage holes evenly distributed circumferentially. The return water annular cavity 114 is connected to the return water pipe 122 through the flow passage holes, and a one-way valve 1210 is provided in the flow passage holes. The one-way valve 1210 can ensure that the cooling water flows in one direction, so that the cooling water after heat exchange returns to the water tank 124 after passing through the one-way valve 1210 and the return water pipe 122 under the action of the return cylinder 112 and the inner wall of the shell 111, thus avoiding backflow.

[0040] Reference Figure 2 Since the upper cooling roller 11 needs to rotate while the water pump 123 and water tank 124 need to be fixed during operation, in this embodiment, both the inlet pipe 121 and the return pipe 122 have two parts: a moving pipe and a stationary pipe. Specifically, the inlet pipe 121 includes a rotating inlet pipe 1211 and a fixed inlet pipe 1212. The return pipe 122 includes a rotating return pipe 1221 and a fixed return pipe 1222. The cooling system 12 also includes a converter 1213, whose outer ring is connected to the rotating return pipe 1221 and the fixed return pipe 1222, and whose inner ring is connected to the rotating inlet pipe 1211 and the fixed inlet pipe 1212. Thus, when the rotating inlet pipe 1211 and the rotating return pipe 1221 rotate with the upper cooling roller 11, the water pump 123 and the water tank 124 can remain fixed. In addition, converter 1213 is existing technology and will not be described in detail here.

[0041] Reference Figure 1 The temperature acquisition device 3 can collect the temperature of the inner and outer walls, the 1 / 4 thickness section, and the center of the cylindrical section 5 in real time. Specifically, the temperature acquisition device 3 includes two surface temperature sensors 31, two 1 / 4 thickness temperature sensors 32, and one center temperature sensor 33. The two surface temperature sensors 31 are respectively disposed on the inner and outer surfaces of the cylindrical section 5, while the two 1 / 4 thickness temperature sensors 32 and the center temperature sensor 33 are all disposed on the end face of the cylindrical section 5. It should be noted that the two 1 / 4 thickness temperature sensors 32 detect the temperature at a distance of 1 / 4 thickness from the inner and outer surfaces of the cylindrical section's sidewall. The center temperature sensor 33 detects the temperature at a distance of 1 / 2 thickness from the inner and outer surfaces of the cylindrical section's sidewall.

[0042] Temperature acquisition device 3, flow regulating valve 126, and flow meter 129 are all communicatively connected to control unit 4. Control unit 4 generates a temperature distribution curve for cylinder section 5 based on the temperature values ​​received from temperature acquisition device 3, and adjusts the opening of flow regulating valve 126 according to this curve, forming a feedback regulation loop to adjust the cooling capacity of upper cooling roller 11. Flow meter 129 corrects the opening of flow regulating valve 126 by detecting fluctuations in the flow rate of cooling water in inlet pipe 121, overcoming interference from flow fluctuations and forming a feedforward regulation loop. In summary, the interaction of these components forms a feedforward-feedback regulation loop, adjusting the opening of flow regulating valve 126, thereby regulating the cooling capacity of upper cooling roller 11 and maintaining a stable temperature gradient in cylinder section 5. This improves differential temperature rolling accuracy, enhances the central microstructure distribution of cylinder section 5, and improves the mechanical properties of cylinder section 5.

[0043] Reference Figures 1 to 6 The working principle of this application embodiment is as follows: A certain amount of cooling water is stored in the water tank 124 through the inlet flange 1241. Under the action of the water pump 123, the cooling water flows from the water tank 124 into the inlet pipe 121. After the flow rate is regulated by the flow regulating valve 126, it continues to flow in the pipe. After passing through the converter 1213, it flows to the spray nozzles 128 of each layer, and then is sprayed out through the nozzles 127. The sprayed cooling water directly contacts and cools the inner wall surface of the shell 111, thereby cooling the outer wall surface. Subsequently, under the action of the return cylinder 112 and the inner wall surface of the shell 111, the cooling water flows from the center to both sides. After passing through the one-way valve 1210 on the side support plate 117, it enters the return water pipe 122 and finally returns to the water tank 124. The baffle 118 in the return cylinder 112 can prevent the water from sliding down from top to bottom, ensuring the flow path of the water. The one-way valve 1210 can ensure that backflow does not occur. The circulating flow of cooling water keeps the wall of the upper cooling roller 11 at a low temperature, allowing it to exchange heat with the inner and outer walls of the cylinder section 5. Simultaneously, air cooling helps create a stable temperature gradient on the cylinder section 5 before rolling. After rolling begins, the opening of the flow regulating valve 126 is adjusted by the control unit 3, thereby changing the surface temperature of the upper cooling roller 11, affecting the heat exchange effect, and maintaining the stability of the temperature gradient on the cylinder section 5.

[0044] In this embodiment, the cooling medium is preferably cooling water. The water level in the water tank 124 is maintained at 1 / 2 to 2 / 3 of the height of the water tank 124, and the minimum height is not less than 1m. The maximum temperature that the temperature acquisition device 3 can acquire is 1500℃, and the maximum range of the flow meter 129 is 500m³. 3 / h. The maximum flow rate of each nozzle layer (128) is 100m³ / h. 3 Twelve layers of nozzles 128 are symmetrically arranged axially on both sides of the upper cooling roller 11, with 12 nozzles in each layer. The outer diameter of the cylinder section 5 is 7200mm, the thickness is 600mm, and the pre-rolling temperature is 1000 degrees Celsius. The length of the cylinder section 5 is 2800mm, and the length of the upper cooling roller 11 is 3000mm, ensuring uniform axial cooling of the cylinder section 5. The circumferential speed of the cylinder section 5 is 150mm / s, determined by the upper cooling roller 11 and the lower roller 42. The thickness of the shell 111 at the center is 180mm, the thickness of both sides is 150mm, the thickness of the upper end of the inner wall slope is 100mm, and the thickness of the lower end is 125mm. The thickness of the center support plate 605 is 200mm, the thickness of the outer perimeter is 100mm, and the thickness of the side support plate 117 is 80mm, to ensure the strength of the upper cooling roller 11. Twelve one-way valves 1210 are evenly distributed circumferentially on the side support plate 117.

[0045] The cylinder section 5 is rolled in annular shape under the action of the upper cooling roller 11 and the lower cooling roller. As the diameter of the cylinder section 5 increases, the upper cooling roller 11 gradually moves outward, always maintaining contact with the cylinder section 5. During the rolling process, the outer surface of the upper cooling roller 11 is kept at a low temperature and exchanges heat with the inner and outer surfaces of the cylinder section 5.

[0046] On the other hand, this application also provides a cooling method based on the cooling device for forming a stable temperature gradient in the above-mentioned large-section differential temperature rolling, including the following steps: Step 1: Before rolling begins, the temperature acquisition device 3 collects the temperature values ​​of the inner and outer walls, 1 / 4 thickness, and center of the idling cylinder section 5 in real time; the control unit 4 generates a temperature distribution curve based on the received temperature values.

[0047] Step 2: Control unit 4 adjusts the opening of flow regulating valve 126, and spray assembly 125 sprays water to cool the inner wall of the outer shell 111 of upper cooling roller 11, so that the inner and outer surfaces of upper cooling roller 11 are at low temperature. Under the combined action of cooling of upper cooling roller 11 and air cooling, a preset temperature gradient is formed on cylinder section 5.

[0048] Step 3: After rolling begins, the control unit 4 continues to receive the temperature value detected by the temperature acquisition device 3, and adjusts the opening of the flow regulating valve 126 according to the temperature value, thereby adjusting the temperature of the outer surface of the upper cooling roller 11. The upper cooling roller 11 and the lower cooling roller contact the cylinder section 5 for cooling, maintaining the stability of the temperature gradient between the inner and outer surfaces of the cylinder section 5, refining the core structure of the cylinder section 5, ensuring rolling accuracy, and improving the mechanical properties of the cylinder section 5.

[0049] In summary, the embodiments of this application, through feedforward-feedback control, can effectively resist interference with temperature control during the rolling process, precisely adjust the surface temperatures of the upper cooling roll 11 and the lower cooling roll, thereby maintaining the stability of the temperature gradient of the roll section 5 and helping to achieve the differential temperature rolling process of large roll sections. This helps to promote the penetration of deformation into the center and improve the overall mechanical properties.

[0050] The above are merely specific embodiments of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A cooling device for forming a stable temperature gradient in large-scale differential temperature rolling, characterized in that, It includes a temperature acquisition device, a control unit, an upper cooling support device, and a lower cooling support device; the upper cooling support device and the lower cooling support device are respectively supported on the inner and outer walls of the cylinder section; The upper cooling support device includes an upper cooling roller and a cooling system symmetrically arranged on both sides of the upper cooling roller; the upper cooling roller includes a shell, a return cylinder and a central support plate; the return cylinder is sleeved inside the shell, and a return water annular cavity is formed between the shell and the return cylinder; the central support plate divides both the return water annular cavity and the inner cavity of the return cylinder into two parts; The lower cooling support device includes a lower cooling roller and a cooling system symmetrically arranged on both sides of the upper cooling roller; the structure of the lower cooling roller is the same as that of the upper cooling roller, and the diameter of the lower cooling roller is larger than that of the upper cooling roller. The cooling system includes an inlet water pipe, a return water pipe, a water pump, a water tank, and multiple spray components; the spray components, the inlet water pipe, the water pump, and the water tank are connected in sequence; the spray components can spray cooling onto the inner wall surface of the shell; the return water annular cavity is connected to the water tank through the return water pipe; a flow regulating valve is provided on the inlet water pipe; The temperature acquisition device can collect the temperature of the inner and outer walls, 1 / 4 thickness, and center of the cylinder section in real time; the temperature acquisition device and the flow regulating valve are both connected to the control unit. The control unit can generate a cylinder section temperature distribution curve based on the temperature value collected by the temperature acquisition device, and adjust the opening of the flow regulating valve according to the cylinder section temperature distribution curve. The return cylinder includes a return cylinder body and side support plates disposed at both ends of the return cylinder body; the side support plates are annular; the outer circular surface of the side support plates is connected to the inner wall of the shell, and the inner hole is connected to the outer wall of the inlet pipe; the shell has openings at both ends; the outlet of the return pipe is connected to the opening of the shell; the return pipe is sleeved on the outside of the inlet pipe; the side support plates are provided with flow holes, and the return annular cavity is connected to the return pipe through the flow holes; a one-way valve is provided in the flow holes. Multiple spraying assemblies are evenly arranged in layers along the axial direction of the water inlet pipe; spraying assemblies located in the same layer are evenly distributed along the circumference of the water inlet pipe; each spraying assembly includes a nozzle and a spray pipe disposed between the nozzle and the water inlet pipe; the nozzle is located within the return water ring cavity.

2. The cooling device for forming a stable temperature gradient in large-scale cylindrical section differential temperature rolling according to claim 1, characterized in that, Both the inner wall of the shell and the outer wall of the reflux cylinder are sloping surfaces that are higher in the middle and lower on both sides.

3. The cooling device for forming a stable temperature gradient in large-scale cylindrical section differential temperature rolling according to claim 2, characterized in that, The water inlet pipe is connected to the side of the central support plate; the water inlet pipe includes a rotating water inlet pipe and a fixed water inlet pipe; the return water pipe includes a rotating return water pipe and a fixed return water pipe; the cooling system also includes a converter; the outer ring of the converter is connected to the rotating return water pipe and the fixed return water pipe at both ends, and the inner ring is connected to the rotating water inlet pipe and the fixed water inlet pipe at both ends.

4. The cooling device for forming a stable temperature gradient in large-scale cylindrical section differential temperature rolling according to claim 3, characterized in that, The nozzle is a conical nozzle, and on the plane of maximum water flow, the water flow from two adjacent nozzles overlaps with each other.

5. The cooling device for forming a stable temperature gradient in large-scale cylindrical section differential temperature rolling according to claim 4, characterized in that, The central support plate includes a circular support plate and an outer ring plate disposed on the outer periphery of the circular support plate; the outer ring plate is connected to the inner wall of the shell; the thickness of the outer ring plate is less than the thickness of the circular support plate.

6. The cooling device for forming a stable temperature gradient in large-scale cylindrical section differential temperature rolling according to claim 5, characterized in that, A flow meter is installed on the water inlet pipe, and the flow meter is also connected to the control unit. The control unit can fine-tune the opening of the flow regulating valve according to the detected value of the flow meter.

7. The cooling device for forming a stable temperature gradient in large-scale cylindrical section differential temperature rolling according to claim 6, characterized in that, The temperature acquisition device includes two surface temperature sensors, two temperature sensors at 1 / 4 thickness, and one center temperature sensor; the two surface temperature sensors are respectively set on the inner and outer surfaces of the cylinder section; the two temperature sensors at 1 / 4 thickness and the center temperature sensor are all set on the end face of the cylinder section.

8. A cooling method based on a cooling device for forming a stable temperature gradient in large-scale cylindrical section differential temperature rolling according to any one of claims 1 to 7, characterized in that, Includes the following steps: S1. Before rolling begins, the temperature acquisition device collects the temperature values ​​of the inner and outer walls, 1 / 4 thickness, and center of the idling cylinder section in real time; the control unit generates a temperature distribution curve based on the received temperature values. S2. The control unit adjusts the initial opening of the flow regulating valve according to the temperature distribution curve, and the spray assembly sprays water to cool the inner wall of the upper or lower cooling roller. Under the combined action of cooling by the upper or lower cooling roller and air cooling, a preset temperature gradient is formed on the cylinder section. S3. After rolling begins, the control unit continues to receive the temperature value detected by the temperature acquisition device and adjusts the opening of the flow regulating valve according to the temperature value to maintain a stable temperature gradient in the cylinder section.

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