Method for operating an annealing furnace roller motor

Abstract

The application discloses an annealing furnace roller motor operation control method. Through the operation safety evaluation function of an automatic control system and the speed redundancy control function, even if one or a few of the furnace roller motors are faulty, the production line can continue to operate under the premise of ensuring the production process quality after the safe operation evaluation of the control system, so that the production efficiency of the continuous annealing unit is improved.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of annealing furnaces, and particularly relates to a control method for operation of furnace roller motors of an annealing furnace. BACKGROUND

[0002] A continuous annealing unit generally has no less than 100 furnace rollers, and the furnace rollers are generally driven by variable frequency asynchronous motors to heat the strip steel in a moving state. Since the furnace roller motors work in a high-temperature environment for a long time, they are prone to failure, which causes the production line to stop, the strip steel in the furnace to suddenly stop moving at a high speed, and a large number of degraded products to be generated. Especially when producing thin-gauge strip steel below 0.6 mm, the strip steel will be severely warped. Therefore, higher requirements are put forward for the stability of the furnace roller motors. The failure of any furnace roller motor in the current control system will cause the production line to stop quickly, which greatly affects the production line.

[0003] A furnace roller control method and device disclosed in CN 113862456 A control the odd-numbered furnace rollers and the even-numbered furnace rollers in the annealing furnace to rotate in opposite directions after the annealing furnace abnormally stops, so as to solve the problem of deformation and jamming of the furnace rollers in the annealing furnace due to uneven heating caused by stopping.

[0004] To solve the above problems, a control method for operation of furnace roller motors of an annealing furnace is provided. To reduce process downtime caused by furnace roller motor failure and improve the quality of the production process, the speed redundancy control technology is used after the safety evaluation of the control system, so as to solve the problem of downtime caused by furnace roller motor failure and improve the production efficiency of the continuous annealing unit. SUMMARY

[0005] The application aims to provide a control method for operation of furnace roller motors of an annealing furnace.

[0006] The application solves the technical problems by adopting the technical scheme of a control method for operation of furnace roller motors of an annealing furnace, which comprises a running safety evaluation function and a speed redundancy control function.

[0007] The running safety evaluation function is used to acquire the tension value of the vertical annealing furnace area, the torque feedback value and the speed feedback value of the running furnace roller motor.

[0008] When the furnace roller motor fails, the failed furnace roller motor is free to follow as a driven roller, the number of the running furnace roller motors is not equal to the number of the pre-running furnace roller motors, and the running safety evaluation function is started.

[0009] When the number of non-adjacent furnace roller motor fault stations is ≥1, the speed difference |Vref-Vact| of the set speed and the speed feedback value of the running furnace roller motor is <N, and the fluctuation range |(Fref-Fact)|÷Fref of the set tension and the feedback tension value of the annealing furnace area is ≤M, at this time, the running safety evaluation has no risk, and the furnace roller motor fault early warning prompt is popped up on the man-machine interface;

[0010] When the number of non-adjacent furnace roller motor fault stations is ≥1, the speed difference |Vref-Vact| of the set speed and the speed feedback value of the running furnace roller motor is <N, and the fluctuation range |(Fref-Fact)|÷Fref of the set tension and the feedback tension value of the annealing furnace area is >M, and the torque feedback value of the running furnace roller motor is >rated torque, the running safety evaluation has risk, and the system sends a fast stop request;

[0011] When the set speed and the feedback speed value of any one of the running furnace roller motors is N≤|Vref-Vact|<1.5×N, the running safety evaluation has risk, and a fast stop request is sent;

[0012] Wherein Vref: furnace roller motor set speed; Vact: furnace roller motor speed feedback value; Fref: set tension; Fact: feedback value of the tension meter; N: maximum allowable speed difference, taken as 0.2 m / s; M: allowable fluctuation range of tension, taken as 25%

[0013] When two adjacent furnace roller motors fail at the same time, the speed difference of the set speed and the speed feedback value of the furnace roller motor is ≥1.5×N, which will definitely cause scratches on the surface of the strip, and the production line continues to run with hidden dangers, the running safety evaluation has risk, the system sends a fast stop request, and N: maximum allowable speed difference, taken as 0.2 m / s;

[0014] The limit number Limit of the pre-set furnace roller fault motor is reached, the production line continues to run with hidden dangers, the running safety evaluation has risk, and the system sends a fast stop request;

[0015] When the speed redundancy control function is started, the production line continues to run, there is no fast stop request in the running safety evaluation function, the production line is in the running mode, the set line speed of the furnace area is not equal to 0 m / s, the number of running furnace roller motors is not equal to the number of pre-running furnace roller motors, and the speed redundancy control function is started.

[0016] Specific is, the running safety evaluation function, for obtaining vertical annealing furnace area tension value, running in the furnace roll motor torque feedback value and speed feedback value, the above-mentioned value comes from the PLC controller, wherein the vertical annealing furnace area tension value, annealing furnace area ABB tension meter is connected to ABB tension meter controller through cable, ABB tension meter controller is transmitted to the slave PLC controller through Profibus Dp communication protocol;The running furnace roll motor torque feedback value is obtained from the internal parameter value r80 of S120 frequency converter, S120 frequency converter and slave PLC controller adopt ProfiNet communication protocol, and data exchange is carried out through Siemens free message, and the running furnace roll motor speed feedback value is connected to SMC30 encoder signal processor through encoder cable, and is connected to S120 frequency converter through Siemens Drive-Cliq cable, and S120 frequency converter and slave PLC controller adopt ProfiNet communication protocol, and data exchange is carried out through Siemens free message.

[0017] Specific is, the slave PLC controller is connected with the master PLC controller through Profibus Dp communication protocol, the master PLC controller obtains the state signal "operation preparation" and "operation enable" signal of furnace roll motor in slave PLC controller, when the furnace roll motor is normally operated, "operation preparation" and "operation enable" PLC logic value is "1" respectively, in fault state, "operation preparation" and "operation enable" PLC logic value is "0" respectively, and "operation preparation" and "operation enable" signal of running furnace roll motor is stored in the data block of master PLC controller, and the fault motor is retrieved through master PLC controller and counted, whether the number of running motors is equal to the number of pre-operated motors, if equal, all furnace roll motors are fault-free, if not equal, the number of pre-operated furnace roll motors with faults is greater than or equal to 1, and the running safety evaluation function is activated.

[0018] Specific is, the "operation preparation" and "operation enable" signals of furnace roll motor come from S120 frequency converter, S120 frequency converter and slave PLC controller adopt ProfiNet communication protocol, and data exchange is carried out through Siemens free message.

[0019] The application has the following beneficial effects: through the running safety evaluation function of automatic control system, speed redundancy control function is completed, under the premise of ensuring production process quality, even if one or a few furnace roll motors are faulty, the production line can continue to run after the safe running evaluation of control system without risk, thereby the production efficiency of continuous annealing unit is improved. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 It is the distribution schematic diagram of annealing furnace roll in the application.

[0021] Figure 2 The control flow chart of the present application. DETAILED DESCRIPTION

[0022] The present application will now be further described in detail with reference to the accompanying drawings.

[0023] As Figures 1-2 The method for controlling the operation of the furnace roller motor of an annealing furnace comprises a master PLC controller (1) and a slave PLC controller (2), the master PLC controller (1) and the slave PLC controller (2) adopt Profibus Dp communication protocol, and the operation is completed in cooperation with a running safety evaluation function (3) and a speed redundancy control function (4).

[0024] The prerequisite conditions for starting the running safety evaluation function include the following contents:

[0025] The master PLC controller (1) acquires the state signals (5) of the furnace roller motor in the slave PLC controller (2), i.e. the “running preparation” and “running enable” signals, when the motor is normally running, the PLC logic values of the “running preparation” and “running enable” are “1” respectively, and in the fault state, the PLC logic values of the “running preparation” and “running enable” are “0” respectively.

[0026] All the “running preparation” and “running enable” signals of the running furnace roller motor are stored in the data block (6) of the master PLC controller, the master PLC controller (1) retrieves the fault motor and counts, whether the number of the running motors is equal to the number of the pre-running motors (7), if they are equal, it means that all the furnace roller motors are not faulty, if they are not equal, it means that the number of the pre-running furnace roller motors with faults is greater than or equal to 1, and the running safety evaluation judgment is activated (8).

[0027] The pre-running furnace roller motor refers to all the furnace roller motors in the annealing furnace area, and the running furnace roller motor refers to all the furnace roller motors in the annealing furnace area minus the fault motor in the furnace area.

[0028] The acquired tension value of the vertical annealing furnace area, the torque feedback value and the speed feedback value of the running furnace roller motor come from the slave PLC controller (2), and the data acquisition process is as follows:

[0029] The ABB tension meter (9) in the annealing furnace area is connected to the ABB tension meter controller (10) through the special cable of the ABB tension meter, and the ABB tension meter controller (10) is transmitted to the slave PLC controller (2) through the Profibus Dp communication protocol.

[0030] The torque feedback value (11) of the running furnace roller motor is acquired from the internal parameter value r80 of the S120 frequency converter (12), the S120 frequency converter (12) and the slave PLC controller (2) adopt ProfiNet communication protocol, and data exchange is carried out through the Siemens 999 free message.

[0031] The furnace roller motor incremental encoder speed feedback value (13) is connected to the SMC30 encoder signal processor (14) through an encoder cable, connected to the S120 frequency converter (12) through a Siemens Drive-Cliq special cable, and the S120 frequency converter (12) exchanges data with the PLC controller (2) through the ProfiNet communication protocol and the Siemens 999 free message.

[0032] The "operation preparation" and "operation enable" signals of the furnace roller motor come from the S120 frequency converter (12), which exchanges data with the PLC controller (2) through the ProfiNet communication protocol and the Siemens 999 free message.

[0033] The operation safety evaluation judgment (8) principle is as follows:

[0034] When the number of non-adjacent furnace roller motor fault stations is greater than or equal to 1 (15);

[0035] The set speed and feedback speed of the furnace roller motor in operation, the speed difference |Vref-Vact|<N (16);

[0036] The set tension and feedback tension fluctuation range of the annealing furnace area |(Fref-Fact)|÷Fref≤M (17), (16) and (17) are satisfied at the same time, the operation safety evaluation has no risk, and the "furnace roller motor fault" early warning prompt (18) is popped up on the human-machine interface.

[0037] When the set tension and feedback tension fluctuation range of the annealing furnace area |(Fref-Fact)|÷Fref>M, and the torque feedback of the furnace roller motor in operation is greater than the rated torque (19), (16) and (19) are satisfied at the same time, the production line continues to run with hidden dangers, the operation safety evaluation has risks, and the system sends a quick stop request (20).

[0038] The set speed and feedback speed of any one of the furnace roller motors in operation, N≤|Vref-Vact|speed difference<1.5×N (21), the operation safety evaluation has risks, and a quick stop request (20) is sent.

[0039] In the formula, Vref: set speed of the furnace roller motor; Vact: feedback value of the furnace roller motor; Fref: set tension; Fact: feedback value of the tension meter; || represents: absolute value; × represents: multiplication sign; N: maximum allowed speed difference, taking 0.2 m / s; M: tension allowed fluctuation range, taking 25%.

[0040] The running safety evaluation function includes: two adjacent furnace roller motors fail at the same time (22), the strip steel and the furnace roller, the speed difference ≥1.5 times N, i.e. 1.5×N (23), which will inevitably cause the surface of the strip steel to be scratched, the production line continues to run with hidden dangers, the running safety evaluation has risks, and the system sends a fast stop request (20). N: the maximum allowed speed difference, which is 0.2 m / s.

[0041] In order to prevent too many furnace roller motor failures from causing the surface of the strip steel to be scratched, the limit number of furnace roller motor failures Limit (limit is a positive integer greater than 1) is preset, and when the number of furnace roller motor failures reaches the limit value (24), the production line continues to run with hidden dangers, the running safety evaluation has risks, and the system sends a fast stop request (20).

[0042] The speed redundancy control function is associated with the following conditions:

[0043] 1) No fast stop request in the running safety evaluation function (3) (25).

[0044] 2) The production line is in the "running" mode, and the set line speed of the furnace area is not equal to 0 m / s (26).

[0045] 3) The number of furnace roller motors in operation is not equal to the number of pre-operated furnace roller motors (27).

[0046] If the above conditions (25), (26), and (27) are met, the production line continues to run, otherwise the annealing furnace area is stopped (28).

[0047] In order to maintain the tension balance of the annealing furnace area and the speed following of the furnace roller, the furnace roller motor does not include a tension roller.

[0048] The annealing furnace area includes: a preheating section, a heating section, a soaking section, a slow cooling section, a fast cooling section, an overaging section, and a final cooling section, each of which has an ABB tension meter, the controller is a Siemens S7-400 PLC series, the furnace roller motor uses a Siemens S120 frequency converter vector control, and there are 105 variable frequency motor drives with speed feedback encoders.

[0049] In operation, five non-adjacent furnace roller motors and two adjacent furnace roller motors are processed by S7-400 PLC to be in an abnormal state (force the furnace roller motor to fail) in turn, respectively. The number of furnace roller motors in operation is not equal to the number of pre-operated furnace roller motors, the running safety evaluation function is activated, and the technical indicators are as follows:

[0050] Table 1: Non-adjacent furnace roller motor failure, running safety evaluation function technical value

[0051] Serial number Number of motors running in advance Number of motors running Number of non-adjacent motor failure Set speed V_ref m / s Feedback speed V_act m / s Difference in furnace roller speed m / s Running safety evaluation function 1 105 105 0 6 6 0 Not activated 2 105 104 1 6 5.95 0.05 Activated 3 105 103 2 6 5.92 0.08 Activated 4 105 102 3 6 5.87 0.13 Activated 5 105 101 4 6 5.81 0.19 Activated 6 105 100 5 6 5.72 0.28 Activated

[0052] Table 2: Adjacent 2 furnace roller motor failure, running safety evaluation function technical value

[0053] Serial number Number of motors running in advance Number of motors running Number of adjacent furnace roller motor failures Strip speed (V_ref) m / s Furnace roller speed (V_act) m / s Difference in furnace roller speed m / s Running safety evaluation function 1 105 103 2 6 5.63 0.37 Activated

[0054] Table 3: Determine system alarm or stop according to risk of operation safety assessment yes / no

[0055] Adjacent 2 motor failures or not Number of motor failures is / are not to the limit value Limit Number of non-adjacent motor failures Difference in furnace roller speed Difference in tension Motor feedback torque is / are not > rated torque Running safety evaluation risk (yes / no) No No 1 ≤ number of non-adjacent motor failures < 5 < 0.2 m / s ≤25% ≤ rated torque No risk: alarm prompt No No 1 ≤ number of non-adjacent motor failures < 5 < 0.2 m / s ＞25% > rated torque Risk: system rapid shutdown No No 1 ≤ number of non-adjacent motor failures < 5 ≥ 0.2 m / s / / Risk: system rapid shutdown No Yes Number of non-adjacent motor failures ≥ 5 0.28 > 0.2 m / s / / High risk: system rapid shutdown Yes No Adjacent 2 motor failures 0.37 > 0.2 m / s / / Risk: system rapid shutdown

[0056] When the production line is in the "running" mode, the number of furnace roller motors in operation is not equal to the number of pre-operation furnace roller motors, and the set line speed of the annealing furnace area is not equal to 0 m / s:

[0057] If there is a risk in the operation safety assessment in Table 3, the speed redundancy control function is not established, and the system stops; if there is no risk in the operation safety assessment in Table 3, the speed redundancy control function is established, and the system continues to run.

[0058] The present application is not limited to the above-mentioned embodiments, and anyone should know that any structural changes made under the inspiration of the present application fall within the protection scope of the present application.

[0059] The technical, shape, and structure parts not described in detail in the present application are all known technologies.

Claims

1. A method for controlling the operation of a furnace roller motor in an annealing furnace, characterized in that, This includes operational safety assessment functions and speed redundancy control functions; The operational safety assessment function is used to obtain the tension value of the vertical annealing furnace area, the torque feedback value of the furnace roller motor during operation, and the speed feedback value. When a furnace roller motor malfunctions, the malfunctioning furnace roller motor acts as a driven roller and follows freely. The number of furnace roller motors in operation is not equal to the number of furnace roller motors in the pre-operational operation, and the operation safety assessment function is activated. When the number of non-adjacent furnace roller motor failures is ≥1, and the speed difference between the set speed and the speed feedback value of the operating furnace roller motor is |Vref-Vact|<N, the fluctuation range between the set tension and the feedback tension value in the annealing furnace area is |(Fref-Fact)|÷Fref≤M. At this time, the operation safety assessment is risk-free, and the human-machine interface will pop up a furnace roller motor failure warning. When the number of non-adjacent furnace roller motor failures is ≥1, and the speed difference between the set speed and the speed feedback value of the operating furnace roller motor is |Vref-Vact|<N, the fluctuation range between the set tension and the feedback tension value in the annealing furnace area is |(Fref-Fact)|÷Fref>M, and the torque feedback value of the operating furnace roller motor is > rated torque, the operation safety assessment is risky, and the system sends a fast stop request. If the set speed and feedback speed value of any of the operating furnace roller motors are N≤|Vref-Vact|<1.5×N, the operation safety assessment indicates a risk, and a fast stop request is sent. Where Vref: set speed of furnace roller motor; Vact: feedback value of furnace roller motor speed; Fref: set tension; Fact: feedback value of tension gauge; N: maximum allowable speed difference, taken as 0.2m / s; M: Permissible tension fluctuation range, taken as 25%. When two adjacent furnace roller motors fail simultaneously, and the speed difference between the set speed and the speed feedback value of the operating furnace roller motor is ≥1.5×N, it will inevitably cause scratches on the strip surface. There is a hidden danger in continuing to operate the production line, and there is a risk in the operation safety assessment. The system sends a rapid stop request. N: maximum allowable speed difference, taken as 0.2m / s. The system sets a limit on the number of faulty furnace roller motors. If the number of faulty furnace roller motors reaches the limit, there is a risk of the production line continuing to operate and the safety assessment of the operation is risky. The system then sends a rapid stop request. The speed redundancy control function is activated when there is no fast stop request in the operation safety assessment function, the production line is in operation mode, the furnace zone set linear speed is not equal to 0 m / s, and the number of furnace roller motors in operation is not equal to the number of pre-operated furnace roller motors. The production line continues to run.

2. The method for controlling the operation of the furnace roller motor in an annealing furnace according to claim 1, characterized in that, The operational safety assessment function is used to obtain the tension value of the vertical annealing furnace area, the torque feedback value of the operating furnace roller motor, and the speed feedback value. These values ​​are obtained from the slave PLC controller. The tension value of the vertical annealing furnace area is obtained from the ABB tension meter in the annealing furnace area, which is connected to the ABB tension meter controller via a cable. The ABB tension meter controller transmits the data to the slave PLC controller via the Profibus DP communication protocol. The torque feedback value of the operating furnace roller motor is obtained from the internal parameter value r80 of the S120 frequency converter. The S120 frequency converter and the slave PLC controller use the ProfiNet communication protocol and exchange data via Siemens free messages. The speed feedback value of the operating furnace roller motor is obtained from the SMC30 encoder signal processor via an encoder cable, which is then connected to the S120 frequency converter via a Siemens Drive-Cliq cable. The S120 frequency converter and the slave PLC controller use the ProfiNet communication protocol and exchange data via Siemens free messages.

3. The method for controlling the operation of the furnace roller motor in an annealing furnace according to claim 2, characterized in that, The slave PLC controller is connected to the master PLC controller via the Profibus DP communication protocol. The master PLC controller obtains the status signals "Running Preparation" and "Running Enable" signals of the furnace roller motor from the slave PLC controller. When the furnace roller motor is running normally, the PLC logic values ​​of "Running Preparation" and "Running Enable" are "1" respectively. Under fault conditions, the PLC logic values ​​of "Running Preparation" and "Running Enable" are "0" respectively. The "Running Preparation" and "Running Enable" signals of the running furnace roller motor are stored in the data block of the master PLC controller. The master PLC controller retrieves and counts the faulty motors. It checks whether the number of running motors is equal to the number of pre-running motors. If they are equal, all furnace roller motors are fault-free. If they are not equal, the number of pre-running faulty furnace roller motors is ≥1, and the operation safety assessment function is activated.

4. The method for controlling the operation of the furnace roller motor in an annealing furnace according to claim 3, characterized in that, The "Running Preparation" and "Running Enable" signals of the furnace roller motor come from the S120 frequency converter. The S120 frequency converter and the slave PLC controller use the ProfiNet communication protocol to exchange data through Siemens free messages.

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