A method for heating a graphitized cathode carbon block

Abstract

The present application belongs to the technical field of aluminum electrolysis, and relates to a graphitized cathode carbon block heating control method. The present application determines left and right end contact zones and each carbon block section along a heating circuit, and obtains total current and each zone voltage; calculates two end contact resistances and each carbon block section resistance according to the ratio of zone voltage to total current; calculates resistance change rate and adjacent resistance difference according to continuously sampled section resistance, to form carbon block state parameters; superimposes short-time diagnostic pulses and calculates pulse recovery deviation; combines carbon block state parameters, pulse recovery deviation and two end contact resistances to identify carbon block abnormal section and end contact abnormal zone; outputs adjustment instructions and cyclic control until graphitization heating ends. The present application solves the problems of inability to distinguish end contact heat generation from carbon block section heat generation and lack of internal abnormality exploration, and achieves the effects of distinguishing heat generation positions, identifying abnormalities, implementing targeted adjustment and improving carbon block length direction heating uniformity.

Description

Technical Field

[0001] This invention belongs to the field of aluminum electrolysis technology and relates to a method for controlling the heating of a graphitized cathode carbon block. Background Technology

[0002] The graphitized cathode carbon block is a key conductive component of the aluminum electrolysis cell. Its graphitization process requires heating the carbon block to the graphitization temperature range by applying electricity. During the graphitization heating process, the heating current forms a path through the electrodes, and the heating process of the carbon block is controlled by adjusting the heating power.

[0003] Existing heating control methods primarily adjust power based on the total current and voltage of the heating circuit or the temperature of external measuring points, failing to distinguish between the heat generated in the end contact area and the segmented heat generated by the carbon block. When the contact state between the electrode and the carbon block changes due to temperature variations, the heat generated at the end contact fluctuates accordingly. If control is still based on the total circuit output, the heat generated at the end contact can easily be misinterpreted as an overall heating trend of the carbon block, leading to overheating at the end or underheating in the middle, affecting the heating uniformity along the length of the carbon block.

[0004] Furthermore, existing methods lack proactive means to detect the internal electrical response characteristics of the carbon block during heating. The adjustment of the heating current is based solely on steady-state sampling values. When local contact anomalies, microcrack expansion, or abnormal internal temperature gradients occur inside the carbon block, surface temperature measurement cannot reflect the changes in the internal state, causing anomalies to accumulate continuously during heating without timely detection and correction. Summary of the Invention

[0005] In view of this, in order to solve the problems mentioned in the background art, a heating control method for graphitized cathode carbon blocks is proposed.

[0006] The objective of this invention can be achieved through the following technical solution: a heating control method for graphitized cathode carbon blocks, comprising: S1, determining the left and right end contact areas and each carbon block segment along the current direction in the heating circuit of the cathode carbon block, and obtaining the total current and the voltage of each segment.

[0007] S2. Based on the ratio of voltage to total current in each section, obtain the contact resistance at both ends and the segment resistance of each carbon block.

[0008] S3. During the continuous sampling period, calculate the resistance change rate of each carbon block and the resistance difference between adjacent carbon blocks based on the segmented resistance of each carbon block to form the carbon block state parameters.

[0009] S4. Superimpose a short-time diagnostic pulse onto the current heating current, obtain the voltage recovery time and residual voltage difference of the left and right contact areas and each carbon block segment after the pulse is removed, and calculate the pulse recovery deviation.

[0010] S5. Compare the state parameters of each carbon block with the state parameters of the adjacent carbon block segments, and identify abnormal carbon block segments by combining the pulse recovery deviation of the corresponding carbon block segments; identify the corresponding contact areas as abnormal end contact areas based on the contact resistance at both ends and the pulse recovery deviation of the contact areas at the left and right ends.

[0011] S6: Output adjustment commands for abnormal carbon block segments, output power reduction commands for abnormal end contact areas, and return to S1 until graphitization heating ends.

[0012] Furthermore, S1 specifically includes: determining the left contact area based on the contact position between the left electrode and the cathode carbon block, and determining the right contact area based on the contact position between the right electrode and the cathode carbon block.

[0013] Between the left and right contact areas, different segment boundaries are determined along the current direction, and the carbon block region between adjacent segment boundaries is taken as the carbon block segment.

[0014] Read the total current of the heating circuit and obtain the potential difference between the left contact area, the right contact area and the two ends of each carbon block segment as the voltage of each segment.

[0015] Furthermore, S2 specifically includes: reading the total current, the voltage of the left contact area, the voltage of the right contact area, and the segmented voltage of each carbon block at the same sampling time.

[0016] Divide the voltage of the left contact area, the voltage of the right contact area, and the segment voltage of each carbon block by the total current to obtain the contact resistance of the left end, the contact resistance of the right end, and the segment resistance of each carbon block, which can be used as the contact resistance at both ends and the segment resistance of each carbon block.

[0017] Furthermore, S3 specifically includes: reading the segment resistance of each carbon block within two consecutive sampling periods according to the arrangement order of each carbon block segment along the current direction.

[0018] The resistance of the same carbon block segment is differentially divided over two consecutive sampling periods to obtain the resistance change of each carbon block, and the resistance change rate of each carbon block is calculated based on the time difference of the sampling periods.

[0019] The resistance difference between adjacent carbon blocks is obtained by differentially dividing the resistance of adjacent carbon blocks within the same sampling period.

[0020] The resistance change rate of each carbon block and the resistance difference between adjacent carbon blocks are linked to form the carbon block state parameters.

[0021] Furthermore, S4 specifically includes: using the segment voltages of the left and right end contact areas and each carbon block segment before pulse superposition as the reference voltage.

[0022] A short diagnostic pulse is superimposed on the current heating current, and the voltage of each segment is read according to the sampling period after the pulse is removed.

[0023] The time from the pulse removal moment to the voltage of each section returning to the reference voltage is taken as the voltage recovery time.

[0024] The difference between the voltage of each segment and the reference voltage after the pulse is removed is taken as the residual voltage difference. The absolute value of the residual voltage difference is multiplied by the voltage recovery time to obtain the pulse recovery deviation.

[0025] Furthermore, S5 specifically includes: calculating the absolute value of the difference between the carbon block state parameters of each carbon block segment and the carbon block state parameters of adjacent carbon block segments, as the carbon block state deviation.

[0026] Calculate the absolute value of the difference between the pulse recovery deviation of each carbon block segment and the pulse recovery deviation of the adjacent carbon block segment, and use it as the carbon block recovery deviation.

[0027] Based on the deviation of carbon block state and the deviation of carbon block recovery in each carbon block segment, the comprehensive deviation of carbon block is obtained, and the carbon block segment with the largest comprehensive deviation is identified as the abnormal carbon block segment.

[0028] By comparing the contact resistance at the left end with that at the right end, and the pulse recovery deviation of the left contact area with that of the right contact area, the contact area with the largest contact resistance and the largest pulse recovery deviation is identified as the end contact abnormal area.

[0029] Furthermore, the method for obtaining the comprehensive deviation of the carbon block is as follows: extract the maximum value among the state deviations of each carbon block as the state normalization benchmark, and extract the maximum value among the recovery deviations of each carbon block as the recovery normalization benchmark.

[0030] Divide the carbon block state deviation of each carbon block segment by the state normalization benchmark to obtain the state normalization value. Divide the carbon block recovery deviation of each carbon block segment by the recovery normalization benchmark to obtain the recovery normalization value.

[0031] Add the state normalization value and the restoration normalization value of the same carbon block segment to obtain the comprehensive deviation value of the carbon block in the same carbon block segment.

[0032] Furthermore, S6 specifically includes: determining the heating zone corresponding to the abnormal segmentation of the carbon block as the carbon block adjustment target.

[0033] When the rate of change of carbon block resistance in an abnormal segment of the carbon block is less than the minimum rate of change of carbon block resistance in the adjacent segment, a power compensation command is output to the carbon block adjustment target.

[0034] When the rate of change of carbon block resistance in an abnormal segment of the carbon block is greater than the maximum rate of change of carbon block resistance in the adjacent segment, a command to reduce the heating rate is output to the carbon block adjustment object.

[0035] When the pulse recovery deviation of the abnormal segment of the carbon block is the maximum value among all carbon block segments, a heat equalization extension command is output to the carbon block adjustment object.

[0036] The electrode corresponding to the abnormal contact area at the end is identified as the end adjustment target. After outputting a power reduction command to the end adjustment target, the process returns to S1 until the graphitization heating ends.

[0037] Furthermore, the method for obtaining the power reduction command is as follows: read the end contact resistance and pulse recovery deviation of the end contact abnormality area.

[0038] Divide the end contact resistance of the abnormal end contact area by the sum of the left end contact resistance and the right end contact resistance to obtain the contact resistance ratio.

[0039] The recovery deviation ratio is obtained by dividing the pulse recovery deviation of the abnormal contact area at the end by the sum of the pulse recovery deviations of the left contact area and the right contact area.

[0040] The average of the contact resistance ratio and the recovery deviation ratio is used as the adjustment coefficient to generate a power reduction command.

[0041] Furthermore, S6 also includes: maintaining the output instruction when the carbon block comprehensive deviation in the next sampling period is less than the carbon block comprehensive deviation in the previous sampling period.

[0042] When the overall deviation of the carbon block in the next sampling period is not less than the overall deviation of the carbon block in the previous sampling period, the abnormal carbon block segmentation is re-identified and the carbon block adjustment object is updated.

[0043] Compared with the prior art, the beneficial effects of the present invention are as follows: (1) The present invention addresses the problem that the existing methods cannot distinguish between end contact heating and carbon block segment heating. By determining the left and right end contact areas and each carbon block segment in the heating circuit along the current direction, the end contact resistance and each carbon block segment resistance are obtained according to the ratio of the voltage of each segment to the total current. This separates the end contact resistance component from the carbon block segment resistance component, thereby achieving the effect of distinguishing end contact heating and carbon block segment heating and avoiding end overheating or middle underheating.

[0044] (2) In view of the problem that existing methods lack the ability to identify internal anomalies in advance, the present invention calculates the resistance change rate of each carbon block segment and the resistance difference between adjacent carbon block segments within a continuous sampling period to form carbon block state parameters, and superimposes a short-time diagnostic pulse on the current heating current to obtain the pulse recovery deviation. The carbon block state parameters and the pulse recovery deviation are combined to identify abnormal segments and abnormal end contact areas of the carbon block, thereby achieving the effect of detecting internal anomalies in advance and outputting targeted adjustment instructions during the heating process. Attached Figure Description

[0045] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0046] Figure 1 This is a flowchart of a heating control method for a graphitized cathode carbon block according to the present invention;

[0047] Figure 2 This is a schematic diagram of the short-time diagnostic pulse and the segment voltage recovery process in this invention;

[0048] Figure 3 This is a schematic diagram of the abnormal adjustment feedback control in this invention. Detailed Implementation

[0049] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0050] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0051] The specific scheme of the graphitized cathode carbon block heating control method provided by the present invention will be described in detail below with reference to the accompanying drawings.

[0052] Please see Figure 1 As shown, the implementation of this invention includes S1 to S6: During the graphitization heating process, the electrode, contact area, and cathode carbon block together form a series heating circuit. The total current, total voltage, and surface temperature of the carbon block are all affected by the end contact state and the internal state of the carbon block. If power adjustment is only based on the steady-state total, it is impossible to distinguish between end contact heating and segmented heating of each carbon block, and it is also difficult to determine the abnormal location corresponding to the local contact state or internal temperature gradient change based on the surface temperature measurement results. Therefore, it is necessary to divide the heating circuit into segments along the current direction, and combine the resistance change during continuous sampling and the dynamic response after the diagnostic pulse is removed to identify and control the heating state of different segments.

[0053] This invention determines the left and right end contact areas and each carbon block segment along the current direction of the heating circuit. Based on the voltage of each segment and the total current, the contact resistance at both ends and the segment resistance of each carbon block are obtained, and carbon block state parameters are formed based on continuous sampling results. On this basis, a short-time diagnostic pulse is superimposed on the current heating current, and the pulse recovery deviation is calculated based on the voltage recovery process after the pulse is removed. Subsequently, abnormal carbon block segments are identified by combining the carbon block state parameters and the pulse recovery deviation, and abnormal end contact areas are identified by combining the contact resistance at both ends and the corresponding pulse recovery deviation. Corresponding adjustment commands are output for different abnormal objects, and the process returns to the segment parameter acquisition process until the graphitization heating is completed. The above process is based on the segmentation of the heating circuit, enabling the separate identification of end contact abnormalities and carbon block segment abnormalities, and forming feedback control for different abnormal locations.

[0054] S1. In the heating circuit of the cathode carbon block, determine the left and right end contact areas and the segments of each carbon block along the current direction, and obtain the total current and the voltage of each segment.

[0055] Before calculating the resistance of different sections in the heating circuit, it is necessary to first determine the section boundaries between the end contact areas and the carbon block body. Since the total voltage of the heating circuit includes voltage components from both the left and right end contact areas and the carbon block body, without segmentation, it is impossible to establish a correspondence between the collected voltages and the corresponding heating areas. Therefore, it is necessary to divide the left and right end contact areas and each carbon block segment along the current direction, and obtain the voltage of each segment separately, providing basic data for subsequent calculations of the end contact resistance and the resistance of each carbon block segment.

[0056] First, the connection relationship between the power output terminal and the left and right electrodes in the heating circuit is read, and the path of current flowing from the positive terminal of the power supply through one electrode, the cathode carbon block, and the other electrode to the negative terminal of the power supply is determined as the current direction. The contact start and end positions of the left electrode and the cathode carbon block are read from the assembly parameters of the heating equipment, and the area between these two positions is determined as the left contact area; the contact start and end positions of the right electrode and the cathode carbon block are read, and the area between these two positions is determined as the right contact area. The boundaries of the left and right contact areas facing the center of the cathode carbon block are respectively determined as the inner boundaries of the corresponding contact areas.

[0057] Secondly, the positions of the potential acquisition points are read from the current heating process configuration. The inner boundary of the left contact area is taken as the first potential acquisition point, and the inner boundary of the right contact area is taken as the last potential acquisition point. The remaining potential acquisition points are set between the two inner boundaries. The potential acquisition points are sorted according to the current direction. Any two adjacent potential acquisition points are taken as a group of segment boundaries, and the carbon block area between these group of segment boundaries is defined as a carbon block segment. The carbon block segments are numbered sequentially according to their arrangement along the current direction.

[0058] Subsequently, the current detection unit installed in the heating circuit is connected to the current acquisition channel of the heating control system, and potential acquisition terminals are respectively set at the two side boundaries of the left and right contact areas and at the boundaries of each carbon block segment. Following the arrangement order of the boundaries along the current direction, each potential acquisition terminal is sequentially connected to the potential acquisition channel of the heating control system. The heating control system reads the potential values ​​of each potential acquisition channel in the same order and uses each read potential value as the potential value at the corresponding boundary position.

[0059] Finally, at the current sampling moment, the heating control system sends a sampling trigger signal to the current acquisition channel and each potential acquisition channel, reads the current value output by the current detection unit as the total current of the heating circuit, and reads the potential value output by each potential acquisition terminal. For the left and right contact areas, the potential value of the upstream boundary of the corresponding contact area is subtracted from the potential value of the downstream boundary to obtain the voltage of the left and right contact areas, respectively; for any carbon block segment, the potential value of the upstream boundary of the carbon block segment is subtracted from the potential value of the downstream boundary to obtain the voltage of the corresponding carbon block segment. The total current, left contact area voltage, right contact area voltage, and voltage of each carbon block segment at the same sampling moment are written into the sampling record in the order of segment arrangement for subsequent calculation of the contact resistance at both ends and the resistance of each carbon block segment.

[0060] S2. Based on the ratio of voltage to total current in each section, obtain the contact resistance at both ends and the segment resistance of each carbon block.

[0061] After obtaining the total current and voltage of each segment, the voltage of each segment only represents the voltage drop of the corresponding segment under the current heating state. It is also necessary to combine this with the total current flowing through the heating circuit to determine the resistance of the corresponding segment. Since the total current during the graphitization heating process changes with the heating power adjustment, if segment voltages and total currents from different sampling times are used for calculation, the resulting resistances will not correspond to the same heating state. Therefore, it is necessary to match the total current and voltage of each segment according to the sampling time, and calculate the contact resistance at both ends and the segmental resistance of each carbon block separately.

[0062] First, using the current sampling time as an index, locate the corresponding record in the sampling log and read the total current, left-end contact area voltage, and right-end contact area voltage from that record. Then, according to the previously determined carbon block segment numbers, sequentially read the voltage of each carbon block segment from the corresponding record, ensuring that the total current, left and right end contact area voltages, and individual carbon block segment voltages all correspond to the current sampling time. Select sampling records with a total current greater than zero for resistance calculation.

[0063] Next, divide the voltage of the left contact area by the total current at the current sampling moment to obtain the left contact resistance; divide the voltage of the right contact area by the total current at the current sampling moment to obtain the right contact resistance. Save the left and right contact resistances according to their corresponding contact areas, as the contact resistances at both ends at the current sampling moment.

[0064] Subsequently, starting from the first carbon block segment number, the corresponding carbon block segment voltage is read. The read carbon block segment voltage is divided by the total current at the current sampling time to obtain the carbon block segment resistance, and the carbon block segment resistance is bound to the corresponding carbon block segment number. Following the arrangement order of the carbon block segments along the current direction, the same calculation is performed on the remaining carbon block segments until the carbon block segment resistances at the current sampling time are obtained.

[0065] Finally, the current sampling time, the left-end contact resistance, the right-end contact resistance, and the segment resistances of each carbon block arranged according to the segment number are written into the segment resistance record for subsequent reading of the segment resistances of each carbon block within the continuous sampling period and calculation of the resistance change rate and the resistance difference between adjacent carbon blocks.

[0066] S3. During the continuous sampling period, calculate the resistance change rate of each carbon block and the resistance difference between adjacent carbon blocks based on the segmented resistance of each carbon block to form the carbon block state parameters.

[0067] The segmented resistance of the carbon block within a single sampling period can only represent the resistance state of each segment at the current moment. It cannot reflect the direction and rate of change of resistance of the same segment during the heating process, nor can it reflect the resistance difference between the current segment and its adjacent segments. Therefore, it is necessary to read the resistance of each segment within two consecutive sampling periods, calculate the rate of change of resistance in the time direction and the resistance difference between adjacent segments in the spatial direction, and bind the calculation results accordingly to form the carbon block state parameter for each segment.

[0068] First, arrange the segment resistance records from earliest to latest according to the sampling time, and select the segment resistance record corresponding to the current sampling period and the segment resistance record corresponding to the previous sampling period. Compare the number of carbon block segments, carbon block segment numbers, and arrangement order in the two segment resistance records. When the number of carbon block segments, numbers, and arrangement order are consistent, and the current sampling time is greater than the previous sampling time, read the resistance of each carbon block segment in the two sampling periods in sequence according to the carbon block segment number. According to the carbon block segments and current direction determined in the previous sampling period, record the total number of carbon block segments as follows: The carbon blocks arranged along the direction of the current are segmented and numbered as follows: ,in, The current sampling period is denoted as the th sampling period. The sampling period is denoted as the previous sampling period. One sampling period.

[0069] Secondly, the resistance of the same carbon block segment is differentially divided over two consecutive sampling periods, and the resistance change and the rate of change of the corresponding carbon block segment are calculated according to the following formula: In the formula, Indicates the first The carbon block segments are in the... The sampling period up to the first The resistance change between sampling periods; This indicates the number of records read from the current section resistance record. Segmented resistors made of individual carbon blocks; This indicates the number of records read from the previous period's segment resistance record. Segmented resistors made of individual carbon blocks; This indicates the sampling time corresponding to the resistance record of the current section; This indicates the sampling time corresponding to the resistance record of the previous period; This represents the time difference between two consecutive sampling periods; Indicates the first The rate of change of carbon block resistance in each carbon block segment during the current sampling period.

[0070] Used to indicate the direction and amount of resistance change of the same carbon block segment between two consecutive sampling periods. Used to define the time range corresponding to the change in resistance; when When it is positive, it indicates that the resistance of the corresponding carbon block segment increases with the sampling period. When the value is negative, it indicates that the resistance of the corresponding carbon block segment decreases with the sampling period.

[0071] Subsequently, based on the resistance of each carbon block segment within the current sampling period, the resistance difference between each carbon block segment and its left and right adjacent carbon block segments is calculated according to the carbon block segment number. The calculation method is as follows: , In the formula, Indicates the first The resistance difference between the left and right adjacent carbon blocks in each carbon block segment within the current sampling period; Indicates the first The resistance difference between the right adjacent carbon block segments within the current sampling period; This indicates the resistance of the previous carbon block segment within the current sampling period; This indicates the resistance of the next carbon block segment in the current sampling period; the absolute value symbol is used to preserve the resistance difference between adjacent carbon block segments.

[0072] For carbon block segment numbered 1, since it has no preceding carbon block segment, the resistance difference between it and carbon block segment numbered 2 is used as both the resistance difference of the corresponding left adjacent carbon block and the resistance difference of the right adjacent carbon block; for segment numbered... The carbon block segment, since it does not have a subsequent numbered carbon block segment, is associated with the segment numbered... The resistance difference between the carbon block segments is simultaneously used as the corresponding resistance difference between the left and right adjacent carbon blocks.

[0073] Finally, the carbon block resistance change rate, the resistance difference between the left and right adjacent carbon blocks, and the resistance difference between the right adjacent carbon blocks corresponding to the same carbon block segment are bound in a fixed order to form the carbon block state parameters: In the formula, Indicates the first The carbon block segments are in the... Carbon block state parameters within each sampling period; The rate of change of carbon block resistance is used to record the resistance change of corresponding carbon block segments in the time direction. and These are the resistance differences between the left and right adjacent carbon blocks, respectively, used to record the resistance differences between the corresponding carbon block segment and its adjacent segments in the spatial direction. The parentheses indicate that the three calculation results are bound according to a fixed field order, not that the three results are directly added together. The current sampling time, carbon block segment number, and corresponding carbon block state parameters are written into the carbon block state record and saved sequentially according to the arrangement of each carbon block segment along the current direction, for subsequent comparison of the state differences between each carbon block segment and its adjacent segments.

[0074] S4. Superimpose a short-time diagnostic pulse onto the current heating current, obtain the voltage recovery time and residual voltage difference of the left and right contact areas and each carbon block segment after the pulse is removed, and calculate the pulse recovery deviation.

[0075] During graphitization heating, the total current changes with power adjustment, and the segment voltages of the left and right contact areas and each carbon block segment also change accordingly. However, the amplitude and duration of current changes caused by each power adjustment are not the same, making it difficult to compare the voltage recovery process of different segments under the same disturbance conditions. The aforementioned carbon block state parameters are calculated from the segment resistance of the carbon block within a continuous sampling period, mainly reflecting the resistance differences of the carbon block segments in the time and spatial directions, and cannot provide a uniform current disturbance condition. Therefore, it is necessary to superimpose a short-time diagnostic pulse with controlled current increment and duration onto the current heating current, so that the left and right contact areas and each carbon block segment are simultaneously subjected to the same current disturbance; after the pulse is removed, the residual voltage difference and voltage recovery time of each segment are obtained based on the segment voltage before the pulse superposition, forming a pulse recovery deviation that can be compared between segments.

[0076] First, a list of sections to be diagnosed is established in the order of the left contact area, the carbon block segments arranged along the current direction, and the right contact area. At the last sampling moment before the short-time diagnostic pulse is superimposed, the voltage of each section is read sequentially according to the list of sections to be diagnosed. The voltage of the left contact area, the voltage of the right contact area, and the voltage of each carbon block segment are used as the reference voltage for the corresponding section, and the section identifier, reference voltage, and sampling time are saved accordingly.

[0077] Secondly, based on the current cathode carbon block specifications and the current heating stage, the corresponding diagnostic ratio and pulse cycle number are read from the system configuration. The system configuration is established through pulse calibration: under the condition that the target heating current during the pulse does not exceed the allowable current of the heating equipment, the current increment and its maintenance period are adjusted until the voltage change in each segment is not less than the voltage acquisition resolution of the corresponding potential acquisition channel; the ratio of the current increment at this point to the heating current before pulse superposition is determined as the diagnostic ratio, and the number of maintenance periods for the current increment is determined as the pulse cycle number. The determined diagnostic ratio and pulse cycle number are then written into the system configuration according to the cathode carbon block specifications and heating stage.

[0078] Subsequently, the current heating current and sampling interval are read, and the current heating current is saved as the heating current before pulse superposition. The heating current before pulse superposition is multiplied by the diagnostic ratio to obtain the current increment to be superimposed. This current increment is then added to the heating current before pulse superposition to obtain the target heating current during the pulse period. The heating control system outputs a pulse superposition command to the heating power supply, switching the current setpoint from the heating current before pulse superposition to the target heating current, and accumulating the pulse duration according to the sampling interval. When the accumulated number of cycles reaches the number of pulse cycles configured in the system, the heating control system stops outputting the pulse superposition command and outputs a pulse removal command to the heating power supply, switching the current setpoint from the target heating current to the saved heating current before pulse superposition. The moment of this switching is recorded as the pulse removal moment.

[0079] Furthermore, starting from the pulse removal moment, acquisition trigger signals are sent to each potential acquisition channel according to the sampling interval. After each sampling cycle, the voltage of the left contact area, the voltage of the right contact area, and the segment voltage of each carbon block are read once, and saved according to the segment identifier and sampling order. For any segment to be diagnosed, the upstream boundary potential acquisition channel and the downstream boundary potential acquisition channel used to acquire the voltage of that segment are determined. The voltage acquisition resolution of the two potential acquisition channels under the current range is read from the channel parameters of the potential acquisition device, and the maximum value of the two voltage acquisition resolutions is determined as the voltage recovery judgment value for that segment. The current voltage recovery difference of the segment is obtained by subtracting the currently read segment voltage from the reference voltage of that segment and taking the absolute value.

[0080] When the current voltage recovery difference of a certain segment is not greater than the voltage recovery judgment value of that segment for the first time, the current sampling time is determined as the recovery time of that segment, and the time between the pulse removal time and the recovery time is determined as the voltage recovery time of that segment. The segment with the determined recovery time stops updating its voltage recovery time, and the remaining segments continue to read voltage according to the sampling period until the recovery time of all segments to be diagnosed is determined.

[0081] Please see Figure 2 As shown, after a short diagnostic pulse is superimposed on the current heating current, the heating current increases during the pulse duration and returns to the current level before the pulse superposition when the pulse is removed. Taking any segment to be diagnosed as an example, the difference between the segment voltage acquired for the first time after the pulse is removed and the reference voltage is the residual voltage difference of that segment. The time from the moment the pulse is removed to the moment the segment voltage first returns to the error range of the reference voltage is the voltage recovery time of that segment. The residual voltage difference and the voltage recovery time are used to calculate the pulse recovery deviation of that segment.

[0082] Finally, the voltages of each segment collected in the first sampling period after pulse removal are read according to the segment identifier, and the reference voltage corresponding to the same segment identifier is read from the reference voltage record saved before pulse superposition. The reference voltage is the corresponding segment voltage obtained in the last sampling period before the heating control system outputs the pulse superposition command. The residual voltage difference of the segment is obtained by subtracting the reference voltage of the same segment from the first segment voltage after pulse removal; the absolute value of the residual voltage difference is taken and multiplied by the previously determined voltage recovery time of the segment to obtain the pulse recovery deviation of the segment. The segment identifier, reference voltage, first segment voltage after pulse removal, residual voltage difference, voltage recovery time, and pulse recovery deviation of each segment are written into the pulse recovery record for subsequent comparison of pulse recovery deviations between segments.

[0083] S5. Compare the state parameters of each carbon block with the state parameters of the adjacent carbon block segments, and identify abnormal carbon block segments by combining the pulse recovery deviation of the corresponding carbon block segments; identify the corresponding contact areas as abnormal end contact areas based on the contact resistance at both ends and the pulse recovery deviation of the contact areas at the left and right ends.

[0084] Abnormal carbon block segments do not necessarily exhibit the same degree of deviation in continuous heating sampling and diagnostic pulse sampling. When the carbon block state parameters of a certain segment are close to those of adjacent segments, but its pulse recovery deviation deviates significantly from those segments, comparing only the carbon block state parameters may not identify the perturbation recovery difference of that segment. Similarly, when the pulse recovery deviation of a certain segment is close to that of adjacent segments, but its carbon block resistance change rate or the resistance difference between adjacent segments deviates significantly, comparing only the pulse recovery deviation may not reflect the resistance change difference of that segment during continuous heating. Therefore, it is necessary to calculate the carbon block state deviation and carbon block recovery deviation of each segment relative to adjacent segments separately. Since the calculation objects and value scales of the two types of deviations are different, they need to be normalized separately before synthesizing the comprehensive carbon block deviation, and the abnormal carbon block segments are identified based on the comprehensive carbon block deviation.

[0085] First, according to the current sampling time and carbon block segment number, the carbon block state parameters of each carbon block segment are sequentially read from the carbon block state record, and the pulse recovery deviation of each carbon block segment within the same diagnostic cycle is read from the pulse recovery record. The carbon block segments are matched according to their arrangement along the current direction, so that each carbon block segment corresponds to a set of carbon block state parameters and a pulse recovery deviation. The first item in the carbon block state parameters is the carbon block resistance change rate, the second item is the resistance difference between the left and right adjacent carbon blocks, and the third item is the resistance difference between the right and right adjacent carbon blocks.

[0086] Secondly, for any two adjacent carbon block segments, the absolute values ​​of their carbon block resistance change rates, the resistance difference between the left and right adjacent carbon blocks are subtracted to obtain three field differences: , , In the formula, This indicates the carbon block segment number that is first in the current direction when adjacent carbon block segments are aligned, and the number range is from 1 to the total number of carbon block segments minus 1. This indicates the segment of the next numbered carbon block adjacent to it; Indicates the current sampling period; This represents the absolute value of the difference in the rate of change of carbon block resistance between adjacent carbon block segments. This represents the absolute value of the difference in resistance between the left adjacent carbon block segments; This field represents the absolute value of the difference in resistance between the rightmost adjacent carbon block segments. The three fields are calculated separately to avoid directly subtracting the rate of change of carbon block resistance from the resistance difference between adjacent carbon blocks.

[0087] Subsequently, the maximum values ​​of the differences in the resistance change rate of all carbon blocks, the maximum values ​​of the differences in the resistance difference of all left adjacent carbon blocks, and the maximum values ​​of the differences in the resistance difference of all right adjacent carbon blocks were extracted as the field normalization benchmarks for each of the three fields. For any field, when the corresponding field normalization benchmark is greater than zero, the field difference of the adjacent carbon block segment pair is divided by the corresponding field normalization benchmark to obtain the field normalization difference; when the corresponding field normalization benchmark is zero, the field normalization difference of the field is recorded as zero. The three field normalization differences of the same adjacent carbon block segment pair are added together to obtain the state difference of the adjacent carbon block segment pair. In the formula, , and These represent the field normalized differences obtained after the differences of the three fields have been processed by the corresponding field normalization benchmark; Indicates the number is and numbered The state differences between two adjacent carbon block segments. The normalized differences of each field are dimensionless values, and the sum of the three is used to combine the state differences in the time and space directions.

[0088] For the carbon block segment with the first number, the state difference between it and the next numbered carbon block segment is taken as the carbon block state deviation of that segment; for the carbon block segment with the last number, the state difference between it and the previous numbered carbon block segment is taken as the carbon block state deviation of that segment; for the remaining carbon block segments, the state difference between it and the previous numbered carbon block segment and the state difference between it and the next numbered carbon block segment are read respectively, and the maximum value of the two is taken as the carbon block state deviation of that segment.

[0089] Furthermore, for any two adjacent carbon block segments, the pulse recovery deviations of the two segments are subtracted and their absolute values ​​are taken to obtain the recovery difference of the adjacent carbon block segment pair. For carbon block segments whose numbers are at the first or last position, the recovery difference between them and their only adjacent carbon block segment is taken as the carbon block recovery deviation. For the remaining carbon block segments, the recovery differences between them and the preceding and following carbon block segments are calculated respectively, and the maximum value of the two recovery differences is taken as the carbon block recovery deviation of the segment.

[0090] After obtaining the carbon block state deviation and carbon block recovery deviation for each carbon block segment, the maximum value among all carbon block state deviations is extracted as the state normalization benchmark, and the maximum value among all carbon block recovery deviations is extracted as the recovery normalization benchmark. When the state normalization benchmark is greater than zero, the carbon block state deviation for each carbon block segment is divided by the state normalization benchmark to obtain the state normalization value for the corresponding carbon block segment; when the state normalization benchmark is zero, the state normalization value for each carbon block segment is recorded as zero. When the recovery normalization benchmark is greater than zero, the carbon block recovery deviation for each carbon block segment is divided by the recovery normalization benchmark to obtain the recovery normalization value for the corresponding carbon block segment; when the recovery normalization benchmark is zero, the recovery normalization value for each carbon block segment is recorded as zero.

[0091] The state normalization value and recovery normalization value of the same carbon block segment are added together to obtain the comprehensive deviation value of that carbon block segment. The carbon block segments are then sorted from largest to smallest based on their comprehensive deviation values. When the maximum comprehensive deviation value corresponds to only one carbon block segment, that segment is identified as an abnormal segment. When the maximum comprehensive deviation value corresponds to multiple segments, the maximum value of the recovery deviation value is extracted from these segments, and the segment with the recovery deviation value equal to this maximum value is retained; if the retained result is only one segment, it is identified as an abnormal segment. If the retained result still includes multiple segments, the maximum value of the state deviation value is extracted from the retained segments, and the segment with the state deviation value equal to this maximum value is retained; if the retained result is only one segment, it is identified as an abnormal segment. If the retained result still includes multiple segments, the segment with the smallest number along the current direction is identified as an abnormal segment.

[0092] Finally, the left and right contact resistances at the same sampling time are read from the segment resistance record, and the pulse recovery deviations of the left and right contact areas within the same diagnostic cycle are read from the pulse recovery record. The left and right contact resistances, as well as the pulse recovery deviations of the left and right contact areas, are compared respectively.

[0093] When the contact resistance at the left end is greater than that at the right end, and the pulse recovery deviation of the left end contact area is greater than that of the right end contact area, the left end contact area is identified as an abnormal end contact area; when the contact resistance at the right end is greater than that at the left end, and the pulse recovery deviation of the right end contact area is greater than that of the left end contact area, the right end contact area is identified as an abnormal end contact area.

[0094] When the left-end contact resistance is greater than the right-end contact resistance, but the pulse recovery deviation of the left-end contact area is less than the pulse recovery deviation of the right-end contact area, or vice versa, the two maximum values ​​are located in different contact areas, and the current diagnostic cycle does not identify the end contact anomaly area. When the left-end contact resistance is equal to the right-end contact resistance, or the pulse recovery deviation of the left-end contact area is equal to the pulse recovery deviation of the right-end contact area, the corresponding comparison cannot determine the contact area where the maximum value is located, and the current diagnostic cycle does not identify the end contact anomaly area. The comparison results of the contact resistances and pulse recovery deviations at both ends when no end contact anomaly area is identified are saved for re-comparison in the next sampling cycle.

[0095] The abnormal segmentation of the carbon block, the deviation of the carbon block state in each segment, the carbon block recovery deviation, the state normalization, the recovery normalization, and the comprehensive deviation of the carbon block, as well as the comparison results of the contact resistance at both ends, the comparison results of the pulse recovery deviation at both ends, and the identification results of the abnormal contact area at the end are written into the abnormal identification record for subsequent determination of the adjustment object and generation of corresponding control commands.

[0096] S6: Output adjustment commands for abnormal carbon block segments, output power reduction commands for abnormal end contact areas, and return to S1 until graphitization heating ends.

[0097] After identifying abnormal carbon block segments and end contact abnormalities, the identification results need to be converted into corresponding control actions. Specifically, the carbon block resistance change rate of the abnormal segments is used to determine whether to implement power compensation or reduce the heating rate, and the pulse recovery deviation is used to determine whether to extend the soaking time. The end contact resistance and pulse recovery deviation of the end contact abnormality area are used to determine the degree of end power reduction. Therefore, it is necessary to first identify the control target and generate the corresponding command, and then determine whether to maintain or update the command based on the overall deviation change of the carbon block in the next sampling cycle.

[0098] First, the numbers of the abnormal carbon block segments are read, and according to the one-to-one correspondence between the carbon block segment numbers and the heating zone numbers, the heating zones with the same numbers are identified as the carbon block adjustment targets. The current output power is read from the power control unit corresponding to the carbon block adjustment target, and the current target heating rate and the current planned end time of homogenization are read from the process execution record of the current heating stage.

[0099] The standard graphitization heating process curve corresponding to the cathode carbon block specifications, along with the adjustment parameters of the heating equipment and heating control system, are read. The minimum power adjustment amount and the upper limit of the equipment's allowable output power are read from the power control unit corresponding to the carbon block adjustment object, and the minimum power adjustment amount is used as the power compensation step size. The minimum target heating rate adjustment amount is read from the heating control system and used as the heating rate reduction step size. The allowable minimum single-cycle soaking time adjustment amount is read from the heating process program and used as the soaking extension duration. Furthermore, the stage power upper limit and stage heating rate lower limit for the current heating stage are read from the standard graphitization heating process curve. The smaller value between the stage power upper limit and the equipment's allowable output power upper limit is determined as the allowable power upper limit for the heating zone, and the stage heating rate lower limit is determined as the allowable heating rate lower limit. The power compensation step size, heating rate reduction step size, soaking extension duration, allowable power upper limit for the heating zone, and allowable heating rate lower limit are written into the process configuration according to the cathode carbon block specifications and heating stage for subsequent generation of corresponding adjustment instructions.

[0100] Secondly, read the carbon block resistance change rate of the abnormal carbon block segment and its adjacent carbon block segments. For the abnormal carbon block segment located at the first or last position, read the carbon block resistance change rate of its only adjacent carbon block segment; for the remaining abnormal carbon block segments, read the carbon block resistance change rate of the preceding and following carbon block segments respectively, and determine the minimum and maximum values ​​of the adjacent carbon block resistance change rates.

[0101] When the rate of change of resistance of an abnormally segmented carbon block is less than the minimum rate of change of resistance of adjacent carbon blocks, a power compensation step is added to the current output power of the carbon block being adjusted to obtain the target output power. If the target output power exceeds the upper limit of the allowable power of the heating zone, the upper limit of the allowable power of the heating zone is taken as the target output power. Subsequently, a power compensation command is sent to the power control unit corresponding to the carbon block being adjusted, so that the heating zone operates at the target output power until the next sampling period.

[0102] When the rate of change of resistance of an abnormally segmented carbon block exceeds the maximum rate of change of resistance of adjacent carbon blocks, a reduction step size in the heating rate is subtracted from the current target heating rate of the carbon block being regulated, resulting in an updated target heating rate. If the updated target heating rate is lower than the lower limit of the allowable heating rate, the lower limit of the allowable heating rate is used as the updated target heating rate. Subsequently, a heating rate reduction command is sent to the temperature control unit corresponding to the carbon block being regulated, causing the heating zone to operate at the updated target heating rate until the next sampling period.

[0103] Furthermore, the pulse recovery deviation of the abnormal carbon block segment is compared with the pulse recovery deviation of the remaining carbon block segments one by one. When the pulse recovery deviation of the abnormal carbon block segment is the maximum value among all carbon block segments, a heat soaking extension time is added to the current planned heat soaking end time to obtain the updated planned heat soaking end time, and a heat soaking extension command is sent to the heating control unit corresponding to the carbon block adjustment object.

[0104] When the power compensation condition or the heating rate reduction condition and the heat soaking extension condition are both met simultaneously, the corresponding target output power, target heating rate, and planned heat soaking end time are combined and written into the same carbon block adjustment instruction. Unmet control conditions are not written into the corresponding control field. If none of the above control conditions are met, the current control parameters of the carbon block adjustment object are maintained, and the next sampling cycle begins. Already generated adjustment instructions only increase or decrease the corresponding adjustment amount during the first output; subsequent maintenance of the instruction does not repeatedly add the adjustment amount.

[0105] Subsequently, it is determined whether an abnormal end contact area has been identified in the current diagnostic cycle. When an abnormal end contact area exists, its corresponding electrode is identified as the end adjustment target, and the current output power, end contact resistance, and pulse recovery deviation of that electrode are read. At the same time, the contact resistance and pulse recovery deviation of the other electrode are read.

[0106] The contact resistance ratio is obtained by dividing the contact resistance of the abnormal contact area by the sum of the contact resistances of the left and right ends. The pulse recovery deviation ratio is then obtained by dividing the pulse recovery deviation ratio of the abnormal contact area by the sum of the pulse recovery deviations of the left and right contact areas. The contact resistance ratio and the recovery deviation ratio are added together and divided by two to obtain the adjustment coefficient. The current output power of the end-adjusted object is multiplied by the adjustment coefficient to obtain the power reduction amount. Finally, the power reduction amount is subtracted from the current output power to obtain the target output power, and a power reduction command is sent to the power control unit corresponding to the end-adjusted object.

[0107] After outputting the carbon block adjustment command and power reduction command, a sampling cycle is run according to the output target control parameters. After the sampling cycle ends, the parameters of each segment are re-acquired, the overall deviation of the carbon blocks in each segment is calculated, and the maximum value is extracted as the maximum value of the overall deviation of the carbon blocks in the next sampling cycle. At the same time, the maximum value of the overall deviation of the carbon blocks in the previous sampling cycle is read and compared with the previous value.

[0108] If the maximum value of the carbon block's overall deviation in the next sampling period is less than the maximum value of the carbon block's overall deviation in the previous sampling period, then the already output target output power, target heating rate, planned end time of heat soaking, and end target output power will be maintained, and the process will continue for one more sampling period. When maintaining the command, only the generated target values ​​will be retained, and the power compensation step size, heating rate reduction step size, or heat soaking extension time will not be repeatedly increased.

[0109] If the maximum value of the overall deviation of the carbon block in the next sampling period is not less than the maximum value of the overall deviation of the carbon block in the previous sampling period, the abnormal carbon block segment is re-identified. If the re-identified abnormal carbon block segment changes, the adjustment command of the original carbon block adjustment object is released, the heating zone corresponding to the new abnormal carbon block segment is determined as the new carbon block adjustment object, and the adjustment command is regenerated according to the new abnormal state; if the re-identified abnormal carbon block segment does not change, the current carbon block adjustment object and its target control parameters are maintained, and the next sampling period begins.

[0110] Please see Figure 3 As shown, after obtaining the anomaly identification results, the corresponding adjustment object is determined based on the abnormal carbon block segments and the abnormal end contact area, and the corresponding adjustment command is output to the adjustment object. After the adjustment command is executed for one sampling cycle, the comprehensive deviation of each carbon block segment is reacquired, and the maximum value of the comprehensive deviation of the carbon block in the next sampling cycle is compared with the maximum value of the comprehensive deviation of the carbon block in the previous sampling cycle. When the maximum value of the comprehensive deviation of the carbon block in the next sampling cycle decreases, the output adjustment command is maintained; when it does not decrease, the abnormal carbon block segments are reidentified and the adjustment object is updated, thus forming a feedback control between anomaly identification, command output, and periodic evaluation.

[0111] Finally, at the end of each sampling cycle, the graphitization heating end flag in the heating process program is read. If the graphitization heating has not yet ended, the segment parameter acquisition, anomaly identification, and command feedback continue; if the graphitization heating has ended, the anomaly adjustment cycle is stopped, the temporary adjustment command that is still in execution is released, and the final control parameters and heating end time are written into the heating control record.

[0112] The above embodiments can be implemented, in whole or in part, by software, hardware, firmware, or any other combination thereof. When implemented using software, the above embodiments can be implemented, in whole or in part, in the form of a computer program product.

[0113] Those skilled in the art will recognize that the algorithmic steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementations should not be considered beyond the scope of this application.

[0114] In addition, the functional modules in the various embodiments of this application can be integrated into one processing module, or each module can exist physically separately, or two or more modules can be integrated into one module.

[0115] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application.

[0116] Finally, the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for controlling the heating of a graphitized cathode carbon block, characterized in that, include: S1. In the heating circuit of the cathode carbon block, determine the left and right end contact areas and the segments of each carbon block along the current direction, and obtain the total current and the voltage of each segment. S2. Based on the ratio of voltage to total current in each section, obtain the contact resistance at both ends and the segment resistance of each carbon block. S3. During the continuous sampling period, calculate the resistance change rate of each carbon block and the resistance difference between adjacent carbon blocks based on the segmented resistance of each carbon block to form the carbon block state parameters. S4. Superimpose a short-time diagnostic pulse onto the current heating current, obtain the voltage recovery time and residual voltage difference of the left and right end contact areas and each carbon block segment after the pulse is removed, in order to calculate the pulse recovery deviation. S5. Compare the state parameters of each carbon block with the state parameters of the adjacent carbon block segments, and identify abnormal carbon block segments by combining the pulse recovery deviation of the corresponding carbon block segments; identify the corresponding contact areas as abnormal end contact areas based on the contact resistance at both ends and the pulse recovery deviation of the contact areas at the left and right ends. S6: Output adjustment commands for abnormal carbon block segments, output power reduction commands for abnormal end contact areas, and return to S1 until graphitization heating ends.

2. The method for controlling the heating of a graphitized cathode carbon block as described in claim 1, characterized in that, S1 specifically includes: The left contact area is determined based on the contact position between the left electrode and the cathode carbon block, and the right contact area is determined based on the contact position between the right electrode and the cathode carbon block. Between the left and right contact areas, different segment boundaries are determined along the current direction, and the carbon block region between adjacent segment boundaries is taken as the carbon block segment. Read the total current of the heating circuit and obtain the potential difference between the left contact area, the right contact area and the two ends of each carbon block segment as the voltage of each segment.

3. The method for controlling the heating of a graphitized cathode carbon block as described in claim 1, characterized in that, S2 specifically includes: At the same sampling time, the total current, the voltage of the left contact area, the voltage of the right contact area, and the segmental voltage of each carbon block are read; Divide the voltage of the left contact area, the voltage of the right contact area, and the segment voltage of each carbon block by the total current to obtain the contact resistance of the left end, the contact resistance of the right end, and the segment resistance of each carbon block, which can be used as the contact resistance at both ends and the segment resistance of each carbon block.

4. The method for controlling the heating of a graphitized cathode carbon block as described in claim 1, characterized in that, S3 specifically includes: According to the arrangement order of each carbon block segment along the current direction, read the resistance of each carbon block segment in two consecutive sampling periods. The resistance of the same carbon block segment is differentially divided in two consecutive sampling periods to obtain the resistance change of each carbon block, and the resistance change rate of each carbon block is calculated based on the time difference of the sampling periods. The resistance difference between adjacent carbon blocks is obtained by differentially analyzing the resistance of adjacent carbon blocks within the same sampling period. The resistance change rate of each carbon block and the resistance difference between adjacent carbon blocks are linked to form the carbon block state parameters.

5. The method for controlling the heating of a graphitized cathode carbon block as described in claim 1, characterized in that, S4 specifically includes: The voltage of the left and right contact areas and the segment voltage of each carbon block segment before pulse superposition are used as the reference voltage. A short-time diagnostic pulse is superimposed on the current heating current, and the voltage of each segment is read according to the sampling period after the pulse is removed. The time from the pulse removal moment to the voltage of each section returning to the reference voltage is taken as the voltage recovery time. The difference between the voltage of each segment and the reference voltage after the pulse is removed is taken as the residual voltage difference. The absolute value of the residual voltage difference is multiplied by the voltage recovery time to obtain the pulse recovery deviation.

6. The method for controlling the heating of a graphitized cathode carbon block as described in claim 3, characterized in that, S5 specifically includes: Calculate the absolute value of the difference between the carbon block state parameters of each carbon block segment and the carbon block state parameters of adjacent carbon block segments, and use it as the carbon block state deviation. Calculate the absolute value of the difference between the pulse recovery deviation of each carbon block segment and the pulse recovery deviation of the adjacent carbon block segment, and use it as the carbon block recovery deviation. Based on the carbon block state deviation and carbon block recovery deviation of each carbon block segment, the comprehensive deviation of the carbon block is obtained, and the carbon block segment with the largest comprehensive deviation is identified as the abnormal carbon block segment. By comparing the contact resistance at the left end with that at the right end, and the pulse recovery deviation of the left contact area with that of the right contact area, the contact area with the largest contact resistance and the largest pulse recovery deviation is identified as the end contact abnormal area.

7. The method for controlling the heating of a graphitized cathode carbon block as described in claim 6, characterized in that, The method for obtaining the overall deviation of the carbon block is as follows: The maximum value among the state deviations of each carbon block is extracted as the state normalization benchmark, and the maximum value among the recovery deviations of each carbon block is extracted as the recovery normalization benchmark. Divide the carbon block state deviation of each carbon block segment by the state normalization benchmark to obtain the state normalization value. Divide the carbon block recovery deviation of each carbon block segment by the recovery normalization benchmark to obtain the recovery normalization value. Add the state normalization value and the restoration normalization value of the same carbon block segment to obtain the comprehensive deviation value of the carbon block in the same carbon block segment.

8. The method for controlling the heating of a graphitized cathode carbon block as described in claim 6, characterized in that, S6 specifically includes: The heating zone corresponding to the abnormal segmentation of the carbon block is identified as the carbon block adjustment target; When the rate of change of carbon block resistance in an abnormal segment of carbon block is less than the minimum rate of change of carbon block resistance in an adjacent segment of carbon block, a power compensation command is output to the carbon block adjustment object. When the rate of change of carbon block resistance in an abnormal segment of the carbon block is greater than the maximum rate of change of carbon block resistance in the adjacent segment, a command to reduce the heating rate is output to the carbon block adjustment object. When the pulse recovery deviation of the abnormal segment of the carbon block is the maximum value among all segments, a heat equalization extension command is output to the carbon block adjustment object. The electrode corresponding to the abnormal contact area at the end is identified as the end adjustment target. After outputting a power reduction command to the end adjustment target, the process returns to S1 until the graphitization heating ends.

9. The method for controlling the heating of a graphitized cathode carbon block as described in claim 8, characterized in that, The method for obtaining the power reduction command is as follows: Read the end contact resistance and pulse recovery deviation in the end contact abnormality area; Divide the end contact resistance of the abnormal end contact area by the sum of the left end contact resistance and the right end contact resistance to obtain the contact resistance ratio; Divide the pulse recovery deviation of the abnormal contact area at the end by the sum of the pulse recovery deviations of the left contact area and the right contact area to obtain the recovery deviation ratio; The average of the contact resistance ratio and the recovery deviation ratio is used as the adjustment coefficient to generate a power reduction command.

10. The method for controlling the heating of a graphitized cathode carbon block as described in claim 8, characterized in that, The S6 further includes: When the carbon block comprehensive deviation in the next sampling period is less than the carbon block comprehensive deviation in the previous sampling period, the output instructions are maintained. When the overall deviation of the carbon block in the next sampling period is not less than the overall deviation of the carbon block in the previous sampling period, the abnormal carbon block segmentation is re-identified and the carbon block adjustment object is updated.

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