Annealing furnace pressure control method and system

Abstract

The application relates to the technical field of steel rolling, and discloses an annealing furnace pressure control method and system. The method comprises the following steps: collecting an outlet furnace pressure at an outlet of an annealing furnace and a target furnace pressure at the outlet of the annealing furnace; obtaining an actual furnace condition of the annealing furnace, wherein the actual furnace condition comprises a normal furnace condition and an abnormal furnace condition; and controlling opening and closing of an adjusting valve of the annealing furnace based on the actual furnace condition, the outlet furnace pressure and the target furnace pressure. According to the technical scheme, the furnace pressure in the annealing furnace can be adjusted and controlled by different adjusting valves according to the furnace condition of the annealing furnace, the outlet furnace pressure of the annealing furnace can be accurately controlled, and quality hidden dangers caused by large fluctuations of the furnace pressure of the annealing furnace can be avoided.

Description

Technical Field

[0001] This application relates to the field of steel rolling technology and discloses a method and system for controlling furnace pressure in an annealing furnace. Background Technology

[0002] The existing cold-rolling continuous horizontal annealing furnace is horizontally arranged and consists of a preheating furnace, an open flame burner heating furnace, a radiant tube heating furnace, a soaking furnace, a cooling furnace, and an outlet sealing chamber. The gas flow direction inside the annealing furnace is opposite to the strip running direction, flowing from the annealing furnace outlet to the inlet. Therefore, the furnace outlet pressure needs to be maintained at a certain value higher than the inlet furnace pressure. Stable furnace pressure is a prerequisite for ensuring a stable atmosphere inside the furnace and preventing oxidation of the strip.

[0003] Currently, in existing technologies, the furnace pressure control of annealing furnaces (with open-flame burner heating sections) mainly relies on a combination of exhaust fans and flue gas dampers to control the furnace pressure in the preheating furnace. This ensures a stable furnace pressure that is lower than the pressure in the outlet sealed chamber, preventing backflow of gas from the furnace into the area between the heating and cooling furnaces. Simultaneously, it maintains a furnace pressure higher than atmospheric pressure to prevent outside air from entering the furnace and causing strip oxidation. However, precise furnace pressure control at the annealing furnace outlet is not possible; only a rough control of the furnace pressure can be achieved by opening and closing the outlet nitrogen manual valve to ensure the furnace pressure meets process requirements. Therefore, the above-mentioned technical solutions cannot achieve stable and precise control of the annealing furnace pressure, and this results in the consumption of protective gas within the annealing furnace not being reduced. Summary of the Invention

[0004] This application relates to the field of steel rolling technology and discloses a method and system for controlling the furnace pressure of an annealing furnace. It can achieve stable and precise control of the furnace pressure and, to a certain extent, reduce the consumption of protective gas in the annealing furnace.

[0005] Other features and advantages of this application will become apparent from the following detailed description, or may be learned in part from practice of this application.

[0006] According to one aspect of the embodiments of this application, a method for controlling the furnace pressure of an annealing furnace is provided. The method includes: collecting the outlet furnace pressure and the target furnace pressure at the outlet of the annealing furnace; obtaining the actual furnace condition of the annealing furnace, the actual furnace condition including normal furnace condition and abnormal furnace condition; and controlling the opening and closing of the regulating valve of the annealing furnace based on the actual furnace condition, the outlet furnace pressure, and the target furnace pressure.

[0007] In one embodiment of this application, based on the foregoing scheme, controlling the opening and closing of the regulating valve of the annealing furnace based on the actual furnace condition, the outlet furnace pressure, and the target furnace pressure includes: if the actual furnace condition is normal, controlling the opening of the first regulating valve of the annealing furnace based on the first furnace pressure difference between the outlet furnace pressure and the target furnace pressure, the first regulating valve being used to regulate the furnace pressure of the annealing furnace; if the actual furnace condition is abnormal, controlling the opening and closing of the second regulating valve of the annealing furnace based on the outlet furnace pressure, the second regulating valve being used to regulate the furnace pressure of the annealing furnace.

[0008] In one embodiment of this application, based on the aforementioned scheme, controlling the opening of the first regulating valve of the annealing furnace based on the first furnace pressure difference between the outlet furnace pressure and the target furnace pressure includes: obtaining the valve opening degree of the first regulating valve; calculating the first furnace pressure difference between the outlet furnace pressure and the target furnace pressure; if the first furnace pressure difference is greater than zero, decreasing the valve opening degree and controlling the first regulating valve to remain continuously open according to the decreased valve opening degree; if the first furnace pressure difference is less than zero, increasing the valve opening degree and controlling the first regulating valve to remain continuously open according to the increased valve opening degree.

[0009] In one embodiment of this application, based on the aforementioned scheme, controlling the opening and closing of the second regulating valve of the annealing furnace based on the outlet furnace pressure includes: acquiring the inlet furnace pressure at the inlet of the annealing furnace; calculating the second furnace pressure difference between the target furnace pressure and the inlet furnace pressure; grouping the second regulating valves based on the second furnace pressure difference and a set grouping pressure threshold to obtain a second regulating valve group; determining a set pressure threshold based on the second furnace pressure difference and the number of valve groups in the second regulating valve group, wherein the set pressure threshold corresponds to the second regulating valve group and is used to determine whether the second regulating valve group is open; and controlling the opening and closing of the second regulating valve group based on the outlet furnace pressure and the set pressure threshold.

[0010] In one embodiment of this application, based on the foregoing scheme, the method further includes: if the actual furnace condition is an abnormal furnace condition, then according to the valve opening, controlling the first regulating valve to remain continuously open until the second regulating valve group is closed.

[0011] In one embodiment of this application, based on the aforementioned scheme, the step of grouping the second regulating valves based on the second furnace pressure difference and the set grouping pressure threshold to obtain a second regulating valve group includes: calculating the ratio of the second furnace pressure difference to the set grouping pressure threshold as the number of valve groups in the second regulating valve group; determining the number of regulating valves in each group of the second regulating valve group based on the number of regulating valves in the second regulating valve and the number of valve groups, and obtaining the second regulating valve group.

[0012] In one embodiment of this application, based on the aforementioned scheme, determining the set pressure threshold based on the second furnace pressure difference and the number of valve groups in the second regulating valve group includes: determining the difference between adjacent set pressure thresholds based on the second furnace pressure difference and the number of valve groups; and determining the set pressure threshold based on the difference between the target furnace pressure and the adjacent set pressure thresholds.

[0013] In one embodiment of this application, based on the aforementioned scheme, controlling the opening and closing of the second regulating valve group based on the outlet furnace pressure and the set pressure threshold includes: for each set pressure threshold, if the outlet furnace pressure is less than the target furnace pressure and the outlet furnace pressure is less than the set pressure threshold, then controlling the second regulating valve group corresponding to the set pressure threshold to remain continuously open.

[0014] In one embodiment of this application, based on the foregoing scheme, after controlling the second regulating valve group corresponding to the set pressure threshold to remain continuously open, the method further includes: if the outlet furnace pressure is greater than or equal to a predetermined set furnace pressure, and the duration reaches the set duration, then controlling the second regulating valve group to remain continuously closed.

[0015] According to one aspect of the embodiments of this application, an annealing furnace pressure control system is provided, the system comprising: a pressure monitoring device for collecting the outlet furnace pressure at the outlet of the annealing furnace and the inlet furnace pressure at the inlet of the annealing furnace; a furnace condition monitoring device for monitoring the actual furnace condition of the annealing furnace; a first regulating valve located near the outlet of the annealing furnace for regulating the furnace pressure of the annealing furnace under normal furnace conditions; a second regulating valve located near the cooling section of the annealing furnace for regulating the furnace pressure of the annealing furnace under abnormal furnace conditions; and a controller for controlling the opening and closing of the first regulating valve and the second regulating valve.

[0016] In the technical solution proposed in this application, the outlet furnace pressure and the target furnace pressure at the outlet of the annealing furnace are collected to obtain the actual furnace condition of the annealing furnace. The actual furnace condition includes normal furnace condition and abnormal furnace condition. Based on the actual furnace condition, the outlet furnace pressure, and the target furnace pressure, the regulating valve of the annealing furnace is controlled to open and close. It can be seen that the technical solution proposed in this application can realize automatic stabilization control of furnace pressure during abnormal unit shutdown. When the outlet pressure of the annealing furnace is higher or lower than the set pressure, the outlet pressure of the annealing furnace is automatically adjusted through the regulating valve in the annealing furnace, avoiding frequent fluctuations in the outlet furnace pressure, reducing manual intervention, and to a certain extent reducing the waste of media in the annealing furnace.

[0017] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and do not limit this application. Attached Figure Description

[0018] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application. It is obvious that the drawings described below are merely some embodiments of this application, and those skilled in the art can obtain other drawings based on these drawings without any inventive effort. In the drawings:

[0019] Figure 1 A schematic diagram of the annealing furnace pressure control system in an embodiment of this application is shown;

[0020] Figure 2 A flowchart of the annealing furnace pressure control method in an embodiment of this application is shown;

[0021] Figure 3 A schematic diagram of the second regulating valve assembly in an embodiment of this application is shown;

[0022] The annotations in the attached figures are explained as follows:

[0023] 100—Annealing furnace pressure control system; 101—Pressure monitoring equipment;

[0024] 102—Furnace condition monitoring equipment; 103—First regulating valve;

[0025] 104—Second regulating valve, 105—Controller

[0026] 106—Annealing furnace; 107—Outlet sealing chamber. Detailed Implementation

[0027] Exemplary embodiments will now be described more fully with reference to the accompanying drawings. However, these exemplary embodiments can be implemented in many forms and should not be construed as limited to the examples set forth herein; rather, these embodiments are provided to make this application more comprehensive and complete, and to fully convey the concept of the exemplary embodiments to those skilled in the art.

[0028] Furthermore, the described features, structures, or characteristics can be combined in any suitable manner in one or more embodiments. Numerous specific details are provided in the following description to give a thorough understanding of embodiments of this application. However, those skilled in the art will recognize that the technical solutions of this application can be practiced without one or more of the specific details, or other methods, components, apparatuses, steps, etc., can be employed. In other instances, well-known methods, apparatuses, implementations, or operations are not shown or described in detail to avoid obscuring various aspects of this application.

[0029] It should be noted that "multiple" in this article refers to two or more. "And / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A alone, A and B simultaneously, or B alone. The character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0030] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such uses of these terms can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in orders other than those illustrated or described.

[0031] The implementation details of the technical solutions in the embodiments of this application are described in detail below:

[0032] Figure 1 A schematic diagram of the annealing furnace pressure control system in an embodiment of this application is shown.

[0033] like Figure 1 As shown, in this application, the annealing furnace pressure control system 100 includes: a pressure monitoring device 101, a furnace condition monitoring device 102, a first regulating valve 103, a second regulating valve 104, and a controller 105; wherein,

[0034] The pressure monitoring device 101 is used to collect the outlet furnace pressure at the outlet of the annealing furnace 106 and the inlet furnace pressure at the inlet of the annealing furnace 106.

[0035] The furnace condition monitoring device 102 is used to monitor the actual furnace condition of the annealing furnace 106;

[0036] The first regulating valve 103 is located near the outlet of the annealing furnace 106 and is used to regulate the furnace pressure of the annealing furnace 106 under normal furnace conditions.

[0037] The second regulating valve 104 is located near the cooling section of the annealing furnace 106 and is used to regulate the furnace pressure of the annealing furnace 106 in case of abnormal furnace conditions.

[0038] The controller 105 is used to control the opening and closing of the first regulating valve 103 and the second regulating valve 104.

[0039] In this application, the annealing furnace 106 is structurally distinguished into an inlet sealing chamber (not shown in the figure), a preheating furnace (not shown in the figure), a heating furnace (not shown in the figure), a soaking furnace (not shown in the figure), a cooling furnace (not shown in the figure), and an outlet sealing chamber 107. The inlet furnace pressure at the inlet of the annealing furnace 106 can be considered as the pressure inside the inlet sealing chamber, and the outlet furnace pressure at the outlet of the annealing furnace 106 can be considered as the pressure inside the outlet sealing chamber 107. The pressure in the preheating furnace, heating furnace, soaking furnace, and cooling furnace is negatively correlated with the distance from the outlet sealing chamber 107; that is, the closer the distance to the outlet sealing chamber 107, the greater the pressure inside the corresponding furnace.

[0040] The annealing furnace 106 may include a heating furnace with an open flame burner and a heating furnace with a radiant tube. The internal pressure of the heating furnace with an open flame burner is prone to fluctuations, and it is necessary to control the internal pressure of the heating furnace with an open flame burner in a timely and accurate manner to avoid large fluctuations in furnace pressure that may cause quality problems.

[0041] The pressure monitoring device 101 can be a micro differential pressure transmitter or other pressure sensors. The pressure monitoring device 101 can monitor the inlet pressure at the inlet of the annealing furnace 106 and the outlet pressure at the outlet of the annealing furnace 106 in real time. By comparing the outlet pressure with the predetermined target pressure, it can be determined whether the furnace pressure in the annealing furnace 106 is stable.

[0042] The furnace condition monitoring device 102 can determine whether the furnace condition in the annealing furnace 106 is normal or abnormal by monitoring whether the strip speed in the annealing furnace 106 is stable, and can also determine the furnace condition of the annealing furnace 106 by monitoring whether the process conditions in the annealing furnace 106 have changed.

[0043] The first regulating valve 103 can be a flow regulating valve. The first regulating valve 103 can be installed in the outlet sealing chamber 107 of the annealing furnace 106. Under normal production conditions, that is, when the furnace condition of the annealing furnace 106 is normal, the valve opening of the first regulating valve 103 can be adjusted by the controller 105 to precisely adjust the furnace pressure of the annealing furnace 106 by increasing or decreasing the flow rate of the protective gas introduced into the annealing furnace 106. The protective gas introduced into the annealing furnace 106 can be nitrogen.

[0044] The second regulating valve 104 can be an emergency nitrogen shut-off valve. It can be located in the outlet sealing chamber 107 of the annealing furnace 106 or in the cooling section of the annealing furnace 106. When the annealing furnace 106 is in normal operating condition, the controller 105 can control the first regulating valve 103 to remain continuously open according to its original valve opening. The second regulating valves 104 can be grouped. Based on the pressure difference between the outlet furnace pressure and the target furnace pressure, the controller 105 can control one or more groups of the grouped second regulating valves 104 to remain continuously open, thereby rapidly adjusting the furnace pressure of the annealing furnace 106 within a short time. The number of the first regulating valve 103 and the second regulating valve 104 can be set according to actual needs and is not limited here.

[0045] Figure 2 A flowchart of the annealing furnace pressure control method in an embodiment of this application is shown.

[0046] like Figure 2 As shown, the furnace pressure control method for the annealing furnace includes at least steps 210 to 250.

[0047] The following will be about Figure 2 Steps 210 to 250 are described in detail below:

[0048] In step 210, the outlet furnace pressure at the annealing furnace outlet and the target furnace pressure at the annealing furnace outlet are collected.

[0049] In this application, the outlet furnace pressure and the target furnace pressure at the outlet of the annealing furnace can be obtained by a micro differential pressure transmitter.

[0050] Continue to refer to Figure 2 In step 230, the actual furnace condition of the annealing furnace is obtained, including normal furnace condition and abnormal furnace condition.

[0051] The actual furnace condition of the annealing furnace can be obtained through furnace condition monitoring equipment. The actual furnace condition of the annealing furnace can be divided into normal furnace condition and abnormal furnace condition. Abnormal furnace condition of the annealing furnace can include: abnormal furnace condition caused by changes in the strip speed in the annealing furnace, and abnormal furnace condition caused by changes in the process conditions in the annealing furnace.

[0052] The process conditions within the annealing furnace may include: the annealing temperature, the heating rate, the cooling method, the steel grade of the slab, and the running speed of the slab within the furnace.

[0053] Continue to refer to Figure 2 In step 250, based on the actual furnace conditions, the outlet furnace pressure, and the target furnace pressure, the regulating valve of the annealing furnace is controlled to open and close.

[0054] Depending on the actual furnace conditions, the furnace pressure can be adjusted by controlling the regulating valves at different positions.

[0055] At the same time, based on the pressure difference between the outlet furnace pressure and the target furnace pressure, it can be determined whether the regulating valve is open and the valve opening degree when the regulating valve is open.

[0056] In one embodiment, controlling the opening and closing of the regulating valve of the annealing furnace based on the actual furnace condition, the outlet furnace pressure, and the target furnace pressure includes: if the actual furnace condition is normal, controlling the opening of a first regulating valve of the annealing furnace based on a first furnace pressure difference between the outlet furnace pressure and the target furnace pressure, wherein the first regulating valve is used to regulate the furnace pressure of the annealing furnace; if the actual furnace condition is abnormal, controlling the opening and closing of a second regulating valve of the annealing furnace based on the outlet furnace pressure, wherein the second regulating valve is used to regulate the furnace pressure of the annealing furnace.

[0057] If the actual furnace condition of the annealing furnace is normal, the furnace pressure of the annealing furnace is adjusted by controlling the first regulating valve of the annealing furnace. Based on the first furnace pressure difference between the outlet furnace pressure and the target furnace pressure, the valve opening of the first regulating valve is determined, and the first regulating valve is controlled to remain continuously open according to the valve opening of the first regulating valve.

[0058] In one embodiment, controlling the opening of a first regulating valve of the annealing furnace based on a first furnace pressure difference between the outlet furnace pressure and the target furnace pressure includes: obtaining the valve opening degree of the first regulating valve; calculating the first furnace pressure difference between the outlet furnace pressure and the target furnace pressure; if the first furnace pressure difference is greater than zero, decreasing the valve opening degree and controlling the first regulating valve to remain continuously open according to the decreased valve opening degree; if the first furnace pressure difference is less than zero, increasing the valve opening degree and controlling the first regulating valve to remain continuously open according to the increased valve opening degree.

[0059] In this application, the outlet furnace pressure at the annealing furnace outlet is monitored by a pressure monitoring device, and the valve opening degree of the first regulating valve is obtained when the outlet furnace pressure is equal to the target furnace pressure.

[0060] When the outlet furnace pressure fluctuates, the first furnace pressure difference is calculated by subtracting the target furnace pressure from the outlet furnace pressure. The valve opening of the first regulating valve is adjusted according to the first furnace pressure difference to obtain the updated valve opening. The first regulating valve is then controlled to remain continuously open according to the updated valve opening.

[0061] If the pressure difference in the first furnace is greater than zero, it can be assumed that the outlet pressure of the annealing furnace is greater than the target furnace pressure. In this case, the mixed gas inside the annealing furnace will be discharged from the outlet, causing unnecessary loss of fuel gas or protective gas. Therefore, according to the set valve opening, the valve opening of the first regulating valve is reduced, and the first regulating valve is kept continuously open according to the reduced valve opening. If the pressure difference in the first furnace is still greater than zero, the valve opening of the first regulating valve is further reduced according to the set valve opening, and the first regulating valve is kept continuously open according to the updated valve opening, until the pressure difference in the first furnace equals zero. The set valve opening can be used as the minimum regulating valve opening for either the first or second regulating valve. The specific value of the set valve opening can be set according to actual needs and is not limited here.

[0062] Furthermore, if the pressure difference in the first furnace is less than zero, it can be assumed that the outlet furnace pressure of the annealing furnace is less than the target furnace pressure. In this case, the furnace pressure difference between the outlet and inlet furnace pressures may be too small, leading to furnace roller caking due to high fuel gas content within the annealing furnace. To avoid furnace roller caking, the opening of the first regulating valve is increased according to the set valve opening, and the first regulating valve is kept continuously open according to the increased valve opening. If the pressure difference in the first furnace is still less than zero, the opening of the first regulating valve is further increased according to the set valve opening, and the first regulating valve is kept continuously open according to the updated valve opening until the pressure difference in the first furnace equals zero.

[0063] Furthermore, it can be assumed that under normal furnace conditions, the furnace pressure of the annealing furnace is continuously adjusted and controlled proportionally by the first regulating valve according to the set valve opening.

[0064] If the actual furnace condition of the annealing furnace is abnormal, the furnace pressure of the annealing furnace is adjusted by controlling the second regulating valve of the annealing furnace. Based on the second furnace pressure difference between the inlet furnace pressure and the target furnace pressure, the second regulating valve is grouped and processed. Based on the outlet furnace pressure and a predetermined set pressure threshold, the opening and closing of the second regulating valve group after grouping is controlled.

[0065] If the second regulating valve is in automatic mode, its opening and closing can be controlled based on the outlet furnace pressure and the target furnace pressure to ensure that the furnace pressure of the annealing furnace quickly reaches a stable state. If the second regulating valve is in manual mode (non-automatic mode), it may be due to inspection and maintenance work being performed on the annealing furnace by personnel. In this case, the second regulating valve cannot be automatically controlled by the controller to prevent accidents to personnel and equipment near the annealing furnace.

[0066] In one embodiment, controlling the opening and closing of the second regulating valve of the annealing furnace based on the outlet furnace pressure includes: acquiring the inlet furnace pressure at the inlet of the annealing furnace; calculating the second furnace pressure difference between the target furnace pressure and the inlet furnace pressure; grouping the second regulating valves based on the second furnace pressure difference and a set grouping pressure threshold to obtain second regulating valve groups; determining a set pressure threshold based on the second furnace pressure difference and the number of valve groups in the second regulating valve groups, wherein the set pressure threshold corresponds to the second regulating valve groups and is used to determine whether the second regulating valve groups are open; and controlling the opening and closing of the second regulating valve groups based on the outlet furnace pressure and the set pressure threshold.

[0067] In this application, the inlet furnace pressure at the annealing furnace inlet can be obtained through a furnace pressure monitoring device, and the second furnace pressure difference between the target furnace pressure and the inlet furnace pressure can be calculated. Based on the calculated second furnace pressure difference and the set group pressure threshold, the second regulating valve can be grouped to obtain the second regulating valve group.

[0068] In one embodiment, the step of grouping the second regulating valves based on the second furnace pressure difference and a set grouping pressure threshold to obtain a second regulating valve group includes: calculating the ratio of the second furnace pressure difference to the set grouping pressure threshold as the number of valve groups in the second regulating valve group; determining the number of regulating valves in each group of the second regulating valve group based on the number of regulating valves in the second regulating valve and the number of valve groups, and obtaining the second regulating valve group.

[0069] The pressure threshold for grouping can be set to 10 Pa, 15 Pa, or as needed, and is not restricted here.

[0070] Specifically, the ratio of the differential pressure of the second furnace to the set group pressure threshold is calculated. If the calculated ratio is a decimal, it can be rounded up or down, and the result is used as the number of valve groups in the second regulating valve group. For example, if the differential pressure of the second furnace is 40 Pa and the set group pressure threshold is 10 Pa, the calculated ratio is 4, then the number of valve groups in the second regulating valve group is 4.

[0071] Based on the number of regulating valves and valve groups of the second regulating valve, the number of regulating valves in each second regulating valve group can be determined according to actual needs, resulting in multiple groups of second regulating valves. The number of regulating valves in a second regulating valve group can be related to the distance between the second regulating valve group and the outlet of the annealing furnace. The closer the distance between the second regulating valve group and the outlet of the annealing furnace, the fewer regulating valves are in the second regulating valve group.

[0072] For example, such as Figure 3 As shown, control valves 1-8 are the second control valves, and control valve 9 is the first control valve. The furnace pressure difference between the inlet furnace pressure and the target furnace pressure of the annealing furnace is 40 Pa. The group pressure threshold is set to 10 Pa. Therefore, the number of valve groups in the second control valve group is 4. Second control valves 1-3 can be used as the first second control valve group, group number Z1. Second control valves 4-5 can be used as the first second control valve group, group number Z2. Second control valves 6-7 can be used as the first second control valve group, group number Z3. Second control valve 8 can be used as the first second control valve group, group number Z4.

[0073] In one embodiment, determining the set pressure threshold based on the second furnace pressure difference and the number of valve groups in the second regulating valve group includes: determining the difference between adjacent set pressure thresholds based on the second furnace pressure difference and the number of valve groups; and determining the set pressure threshold based on the difference between the target furnace pressure and the adjacent set pressure thresholds.

[0074] Specifically, the ratio of the differential pressure of the second furnace to the number of valve groups is calculated, and the calculated ratio is used as the difference between adjacent set pressure thresholds. Based on the difference between the differential pressure of the second furnace and the adjacent set pressure thresholds, each set pressure threshold is determined.

[0075] For example, if the inlet furnace pressure is 20 Pa, the target furnace pressure is 60 Pa, the differential pressure of the second furnace is 40 Pa, and the number of valve groups is 4, then the ratio of the differential pressure of the second furnace to the number of valve groups is 10. Therefore, the difference between adjacent set pressure thresholds should be less than the ratio of the differential pressure of the second furnace to the number of valve groups. Thus, the difference between adjacent set pressure thresholds can be considered as 5 Pa, or 7 Pa. Based on the difference between the differential pressure of the second furnace and adjacent set pressure thresholds, multiple set pressure thresholds can be obtained as P1 = 40 Pa, P2 = 45 Pa, P1 = 50 Pa, and P2 = 55 Pa.

[0076] In one embodiment, controlling the opening and closing of the second regulating valve group based on the outlet furnace pressure and the set pressure threshold includes: for each set pressure threshold, if the outlet furnace pressure is less than the target furnace pressure and the outlet furnace pressure is less than the set pressure threshold, then controlling the second regulating valve group corresponding to the set pressure threshold to remain continuously open.

[0077] Specifically, continue as Figure 3 As shown, the inlet furnace pressure is 20 Pa, the target furnace pressure is 60 Pa, and the second regulating valve is divided into 4 groups, namely Z1 to Z4, with 4 set pressure thresholds of P1=40 Pa, P2=45 Pa, P1=50 Pa, and P2=55 Pa. If the outlet furnace pressure is less than 55 Pa, the second regulating valve of group Z4 is controlled to remain open. If the outlet furnace pressure is less than 50 Pa, the second regulating valve of group Z3 is controlled to remain open. If the outlet furnace pressure is less than 45 Pa, the second regulating valve of group Z2 is controlled to remain open. If the outlet furnace pressure is less than 40 Pa, the second regulating valve of group Z1 is controlled to remain open.

[0078] In one embodiment, after controlling the second regulating valve group corresponding to the set pressure threshold to remain continuously open, the method further includes: if the outlet furnace pressure is greater than or equal to a predetermined set furnace pressure, and the duration reaches the set duration, then controlling the second regulating valve group to remain continuously closed.

[0079] Specifically, the set furnace pressure is lower than the target furnace pressure, but higher than the set pressure threshold. For example, if the four set pressure thresholds are P1 = 40 Pa, P2 = 45 Pa, P1 = 50 Pa, and P2 = 55 Pa, then the set furnace pressure can be 57 Pa. The set time can be 3 seconds or 5 seconds. The set furnace pressure and set time can be set according to actual needs and are not restricted here.

[0080] After the second regulating valve group corresponding to the set pressure threshold is kept continuously open, the outlet furnace pressure gradually increases. As the outlet furnace pressure increases, the second regulating valve group needs to be closed to prevent the outlet furnace pressure from rising too quickly, which would cause drastic fluctuations in the atmosphere inside the annealing furnace.

[0081] Continue as Figure 3As shown, the inlet furnace pressure is 20 Pa, the target furnace pressure is 60 Pa, and the second regulating valve is divided into 4 groups, namely Z1 to Z4. The four set pressure thresholds are P1 = 40 Pa, P2 = 45 Pa, P1 = 50 Pa, and P2 = 55 Pa, respectively. The set furnace pressure can be 57 Pa. If the outlet furnace pressure is greater than or equal to 45 Pa, the second regulating valve of group Z1 is controlled to remain continuously closed. If the outlet furnace pressure is greater than or equal to 50 Pa, the second regulating valve of group Z2 is controlled to remain continuously closed. If the outlet furnace pressure is greater than or equal to 55 Pa, the second regulating valve of group Z3 is controlled to remain continuously closed. If the outlet furnace pressure is greater than or equal to 57 Pa and the duration is greater than the set time, the second regulating valve of group Z4 is controlled to remain continuously closed.

[0082] The set pressure thresholds for each group of second regulating valves when open and when closed are different. If the set pressure threshold when open is used, and the outlet furnace pressure reaches a certain set pressure threshold, closing the corresponding second regulating valve group may cause the outlet furnace pressure to fluctuate and drop below that set pressure threshold again, leading to the second regulating valve group reopening. This could result in the second regulating valve group constantly switching between open and closed states, causing the atmosphere inside the annealing furnace to remain unstable.

[0083] In one embodiment, the method further includes: if the actual furnace condition is an abnormal furnace condition, then according to the valve opening, controlling the first regulating valve to remain continuously open until the second regulating valve group is closed.

[0084] If the actual furnace condition of the annealing furnace changes from normal to abnormal, the valve opening of the first regulating valve before the actual furnace condition becomes abnormal is recorded. Based on the obtained valve opening of the first regulating valve, the first regulating valve is controlled to remain continuously open, that is, the valve opening of the first regulating valve is fixed until the valve group of the second regulating valve is completely closed. At the same time, the actual furnace condition of the annealing furnace changes from abnormal to normal. The furnace pressure of the annealing furnace is then adjusted again by controlling the valve opening of the first regulating valve to maintain a stable atmosphere inside the annealing furnace.

[0085] Depending on the actual furnace conditions, the states of the first and second regulating valves will change. If the furnace is in normal condition, the opening of the first regulating valve is adjusted according to the set valve opening to regulate the furnace outlet pressure, while the second regulating valve remains continuously closed. If the furnace is in abnormal condition, the first regulating valve is kept continuously open according to the recorded valve opening before the abnormal condition, and the second regulating valve is opened or closed based on the furnace outlet pressure to regulate the furnace outlet pressure.

[0086] The one or more technical solutions provided in the embodiments of this application have at least the following technical effects or advantages:

[0087] The technical solution of this application can realize automatic and stable control of furnace pressure after abnormal unit shutdown, and reduce the consumption of protective gas in annealing furnace to a certain extent.

[0088] The technical solution of this application can control the furnace pressure of the annealing furnace by adopting different strategies according to the different actual furnace conditions of the annealing furnace and the predetermined target furnace pressure and outlet furnace pressure.

[0089] This application also provides an annealing furnace pressure control device, the device comprising: a data acquisition unit, an acquisition unit, and a control unit. The data acquisition unit is used to acquire the outlet furnace pressure and the target furnace pressure at the outlet of the annealing furnace; the acquisition unit is used to acquire the actual furnace condition of the annealing furnace, including normal furnace condition and abnormal furnace condition; the control unit is used to control the opening and closing of the regulating valve of the annealing furnace based on the actual furnace condition, the outlet furnace pressure, and the target furnace pressure.

[0090] In some embodiments of this application, based on the foregoing scheme, the control unit is configured to: if the actual furnace condition is normal, control the opening of the first regulating valve of the annealing furnace based on the first furnace pressure difference between the outlet furnace pressure and the target furnace pressure, wherein the first regulating valve is used to regulate the furnace pressure of the annealing furnace; if the actual furnace condition is abnormal, control the opening and closing of the second regulating valve of the annealing furnace based on the outlet furnace pressure, wherein the second regulating valve is used to regulate the furnace pressure of the annealing furnace.

[0091] In some embodiments of this application, based on the foregoing scheme, the control unit is further configured to: obtain the valve opening of the first regulating valve; calculate the first furnace pressure difference between the outlet furnace pressure and the target furnace pressure; if the first furnace pressure difference is greater than zero, decrease the valve opening and control the first regulating valve to remain continuously open according to the decreased valve opening; if the first furnace pressure difference is less than zero, increase the valve opening and control the first regulating valve to remain continuously open according to the increased valve opening.

[0092] In some embodiments of this application, based on the foregoing scheme, the control unit is further configured to: collect the inlet furnace pressure at the inlet of the annealing furnace; calculate the second furnace pressure difference between the target furnace pressure and the inlet furnace pressure; group the second regulating valves based on the second furnace pressure difference and a set grouping pressure threshold to obtain a second regulating valve group; determine a set pressure threshold based on the second furnace pressure difference and the number of valve groups in the second regulating valve group, wherein the set pressure threshold corresponds to the second regulating valve group and the set pressure threshold is used to determine whether the second regulating valve group is open; and control the opening and closing of the second regulating valve group based on the outlet furnace pressure and the set pressure threshold.

[0093] In some embodiments of this application, based on the foregoing scheme, the control unit is further configured to: if the actual furnace condition is an abnormal furnace condition, control the first regulating valve to remain continuously open according to the valve opening degree until the second regulating valve group is closed.

[0094] In some embodiments of this application, based on the foregoing scheme, the control unit is further configured to: calculate the ratio of the second furnace pressure difference to the set group pressure threshold as the number of valve groups in the second regulating valve group; determine the number of regulating valves in each group of the second regulating valve group based on the number of regulating valves in the second regulating valve and the number of valve groups, and obtain the second regulating valve group.

[0095] In some embodiments of this application, based on the foregoing scheme, the control unit is further configured to: determine the difference between adjacent set pressure thresholds based on the second furnace pressure difference and the number of valve groups; and determine the set pressure threshold based on the difference between the target furnace pressure and the adjacent set pressure thresholds.

[0096] In some embodiments of this application, based on the foregoing scheme, the control unit is further configured to: for each set pressure threshold, if the outlet furnace pressure is less than the target furnace pressure and the outlet furnace pressure is less than the set pressure threshold, control the second regulating valve group corresponding to the set pressure threshold to remain continuously open.

[0097] In some embodiments of this application, based on the foregoing scheme, the control unit is further configured to: if the outlet furnace pressure is greater than or equal to a predetermined set furnace pressure, and the duration reaches the set duration, then control the second regulating valve group to remain in a continuously closed state.

[0098] This application also provides a computer program product comprising computer instructions stored in a computer-readable storage medium and adapted to be read and executed by a processor to cause a computer device having the processor to perform the annealing furnace pressure control method as described in any of the above embodiments.

[0099] This application also provides a computer-readable medium, which may be included in an electronic device or exist independently without being assembled into an electronic device. The computer-readable storage medium stores at least one line of program code, which is loaded and executed by a processor to implement the annealing furnace pressure control method described in any of the above embodiments.

[0100] This application also provides an electronic device, which includes one or more processors and one or more memories, wherein at least one piece of program code is stored in the one or more memories, and the at least one piece of program code is loaded and executed by the one or more processors to implement the annealing furnace pressure control method described in any of the above embodiments.

[0101] It should be noted that the computer-readable medium shown in the embodiments of this application can be a computer-readable signal medium or a computer-readable storage medium, or any combination of the two. A computer-readable storage medium can be, for example,—but not limited to—an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination thereof. More specific examples of a computer-readable storage medium may include, but are not limited to: an electrical connection having one or more wires, a portable computer disk, a hard disk, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM), flash memory, optical fiber, portable compact disc read-only memory (CD-ROM), optical storage device, magnetic storage device, or any suitable combination thereof. In this application, a computer-readable storage medium can be any tangible medium containing or storing a program that can be used by or in conjunction with an instruction execution system, apparatus, or device. In this application, a computer-readable signal medium can include a data signal propagated in baseband or as part of a carrier wave, carrying computer-readable program code. Such transmitted data signals can take various forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination thereof. The computer-readable signal medium can also be any computer-readable medium other than a computer-readable storage medium, which can send, propagate, or transmit a program for use by or in connection with an instruction execution system, apparatus, or device. The program code contained on the computer-readable medium can be transmitted using any suitable medium, including but not limited to wireless, wired, etc., or any suitable combination thereof.

[0102] The flowcharts and block diagrams in the accompanying drawings illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to various embodiments of this application. Each block in a flowchart or block diagram may represent a module, segment, or portion of code, which contains one or more executable instructions for implementing a specified logical function. It should also be noted that in some alternative implementations, the functions indicated in the blocks may occur in a different order than those indicated in the drawings. For example, two consecutively indicated blocks may actually be executed substantially in parallel, and they may sometimes be executed in reverse order, depending on the functions involved. It should also be noted that each block in a block diagram or flowchart, and combinations of blocks in a block diagram or flowchart, can be implemented using a dedicated hardware-based system that performs the specified function or operation, or using a combination of dedicated hardware and computer instructions.

[0103] The units described in the embodiments of this application can be implemented in software or hardware, and the described units can also be located in a processor. The names of these units do not necessarily limit the specific unit itself.

[0104] It should be noted that although several modules or units for the device used to perform actions have been mentioned in the detailed description above, this division is not mandatory. In fact, according to the embodiments of this application, the features and functions of two or more modules or units described above can be embodied in one module or unit. Conversely, the features and functions of one module or unit described above can be further divided and embodied by multiple modules or units.

[0105] Through the above description of the embodiments, those skilled in the art will readily understand that the exemplary embodiments described herein can be implemented by software or by combining software with necessary hardware. Therefore, the technical solutions according to the embodiments of this application can be embodied in the form of a software product, which can be stored in a non-volatile storage medium (such as a CD-ROM, USB flash drive, external hard drive, etc.) or on a network, including several instructions to cause a computing device (such as a personal computer, server, touch terminal, or network device, etc.) to execute the method according to the embodiments of this application.

[0106] Other embodiments of this application will readily occur to those skilled in the art upon consideration of the specification and practice of the embodiments disclosed herein. This application is intended to cover any variations, uses, or adaptations of this application that follow the general principles of this application and include common knowledge or customary techniques in the art not disclosed herein.

[0107] Furthermore, the above figures are merely illustrative of the processes included in the method according to exemplary embodiments of this application, and are not intended to be limiting. It is readily understood that the processes shown in the above figures do not indicate or limit the temporal order of these processes. Additionally, it is readily understood that these processes may be executed synchronously or asynchronously, for example, in multiple modules.

[0108] It should be understood that this application is not limited to the precise structures described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of this application is limited only by the appended claims.

Claims

1. A method for controlling furnace pressure in an annealing furnace, characterized in that, The method includes: Collect the outlet furnace pressure at the annealing furnace outlet and the target furnace pressure at the annealing furnace outlet; The actual furnace condition of the annealing furnace is obtained. The actual furnace condition includes normal furnace condition and abnormal furnace condition. The abnormal furnace condition includes abnormal furnace condition caused by changes in the strip speed in the annealing furnace and abnormal furnace condition caused by changes in the process conditions in the annealing furnace. If the actual furnace condition is normal, then based on the first furnace pressure difference between the outlet furnace pressure and the target furnace pressure, the first regulating valve of the annealing furnace is controlled to open. The first regulating valve is used to regulate the furnace pressure of the annealing furnace. If the actual furnace condition is abnormal, the opening and closing of the second regulating valve of the annealing furnace is controlled based on the outlet furnace pressure. The second regulating valve is used to regulate the furnace pressure of the annealing furnace. The first regulating valve is located near the outlet of the annealing furnace and is used to regulate the furnace pressure of the annealing furnace under normal furnace conditions. The second regulating valve is located near the cooling section of the annealing furnace and is used to regulate the furnace pressure of the annealing furnace under abnormal furnace conditions. The control of the opening and closing of the second regulating valve of the annealing furnace based on the outlet furnace pressure includes: Collect the inlet furnace pressure at the inlet of the annealing furnace; Calculate the second furnace pressure difference between the target furnace pressure and the inlet furnace pressure; Calculate the ratio of the differential pressure of the second furnace to the set group pressure threshold, and use it as the number of valve groups in the second regulating valve group; Based on the number of regulating valves in the second regulating valve and the number of valve groups, the number of regulating valves in each second regulating valve group is determined, and the second regulating valve group is obtained. Based on the differential pressure of the second furnace and the number of valve groups in the second regulating valve group, a set pressure threshold is determined. The set pressure threshold corresponds to the second regulating valve group and is used to determine whether the second regulating valve group is open. Based on the outlet furnace pressure and the set pressure threshold, the opening and closing of the second regulating valve group are controlled.

2. The method according to claim 1, characterized in that, The step of controlling the opening of the first regulating valve of the annealing furnace based on the first furnace pressure difference between the outlet furnace pressure and the target furnace pressure includes: Obtain the valve opening degree of the first regulating valve; Calculate the first furnace pressure difference between the outlet furnace pressure and the target furnace pressure; If the pressure difference of the first furnace is greater than zero, the valve opening is reduced, and the first regulating valve is controlled to remain continuously open according to the reduced valve opening. If the pressure difference of the first furnace is less than zero, the valve opening is increased, and the first regulating valve is controlled to remain continuously open according to the increased valve opening.

3. The method according to claim 2, characterized in that, The method further includes: If the actual furnace condition is abnormal, the first regulating valve is controlled to remain continuously open according to the valve opening degree until the second regulating valve group is closed.

4. The method according to claim 1, characterized in that, The determination of the set pressure threshold based on the differential pressure of the second furnace and the number of valve groups in the second regulating valve group includes: Based on the pressure difference of the second furnace and the number of valve groups, the difference between adjacent set pressure thresholds is determined; The set pressure threshold is determined based on the difference between the target furnace pressure and the adjacent set pressure threshold.

5. The method according to claim 4, characterized in that, The step of controlling the opening and closing of the second regulating valve group based on the outlet furnace pressure and the set pressure threshold includes: For each set pressure threshold, if the outlet furnace pressure is less than the target furnace pressure and the outlet furnace pressure is less than the set pressure threshold, then the valve group of the second regulating valve corresponding to the set pressure threshold is controlled to remain continuously open.

6. The method according to claim 5, characterized in that, After controlling the second regulating valve group corresponding to the set pressure threshold to remain continuously open, the method further includes: If the outlet furnace pressure is greater than or equal to a predetermined set furnace pressure, and the duration reaches the set duration, then the second regulating valve group is controlled to remain in a continuously closed state.

7. A furnace pressure control system for an annealing furnace, characterized in that, The system executes the annealing furnace pressure control method as described in any one of claims 1 to 6, the system comprising: Pressure monitoring equipment, wherein the pressure monitoring equipment is used to collect the outlet furnace pressure at the outlet of the annealing furnace and the inlet furnace pressure at the inlet of the annealing furnace; Furnace condition monitoring equipment, wherein the furnace condition monitoring equipment is used to monitor the actual furnace condition of the annealing furnace; The first regulating valve, located near the outlet of the annealing furnace, is used to regulate the furnace pressure of the annealing furnace under normal furnace conditions. The second regulating valve, located near the cooling section of the annealing furnace, is used to regulate the furnace pressure of the annealing furnace in case of abnormal furnace conditions. A controller is used to control the opening and closing of the first regulating valve and the second regulating valve.

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