阅读说明：本技术 热镀锌立式退火炉氮气联锁控制系统操作方法 (Operation method of nitrogen interlocking control system of hot galvanizing vertical annealing furnace ) 是由 王海 张国堂 林明涛 詹旭 于 2019-10-18 设计创作，主要内容包括：本发明提出了热镀锌立式退火炉氮气联锁控制系统操作方法,采用氮气压力与炉压、氢气总阀以及生产线急停或快停进行联锁,氮气总阀处的流量和压力的监控。有益效果：采用联锁控制,限制氮气异常情况下对退火炉及其他设备的损害,降低损失。避免产生大量的氧化铁皮对炉膛内重要设备的污染和造成设备损坏。(The invention provides an operation method of a nitrogen interlocking control system of a hot galvanizing vertical annealing furnace, which interlocks by adopting nitrogen pressure and furnace pressure, a hydrogen main valve and production line sudden stop or quick stop, and monitors the flow and the pressure at the nitrogen main valve. Has the advantages that: and the interlocking control is adopted to limit the damage to the annealing furnace and other equipment under the abnormal condition of the nitrogen and reduce the loss. Avoid producing the pollution of a large amount of iron oxide scales to important equipment in the furnace and causing equipment damage.)

1. The operation method of the nitrogen interlocking control system of the hot galvanizing vertical annealing furnace is characterized in that: the method comprises the following steps of interlocking by adopting nitrogen pressure and furnace pressure, a hydrogen main valve and a production line to stop suddenly or stop quickly, monitoring the flow and pressure at the nitrogen main valve, detecting the nitrogen pressure of an inlet seal roller of an annealing furnace, abnormally reducing the furnace pressure of a preheating section, a heating section, a slow cooling section, a rapid cooling section and a horizontal steering section, detecting the oxygen content of the annealing furnace, detecting the dew point of the annealing furnace, interlocking the furnace temperature and the nitrogen flow pressure in a high-temperature mode to prevent manual misoperation or wrong stop, controlling the minimum flow and pressure of nitrogen, and ensuring that the furnace pressure prevents cold air from entering the annealing furnace in a safety range; the method comprises the steps that nitrogen pressure of an annealing furnace inlet sealing roller in an annealing furnace, a detection instrument is arranged in each section of a preheating section, a heating section, a slow cooling section, a rapid cooling section and a horizontal steering section, changes of the furnace pressure and the nitrogen pressure of the inlet sealing roller are detected, oxygen content and dew point are detected, actual data of one section are higher than or lower than set value data, the opening degree of an alarm unit and a nitrogen flow regulating valve is triggered to carry out remedial adjustment, the nitrogen furnace partial pressure is ensured to be normal, the nitrogen flow is regulated to the maximum value to influence production or can influence the limiting threshold value of the nitrogen pressure and the flow of a main pipe to meet production conditions, a shutdown cooling mode is triggered, the air-fuel ratio of a combustion system is regulated, the gas flow is reduced, the rotating speed of a fan of a cooling section is improved to accelerate; if nitrogen gas furnace partial pressure reduces very fast, unable pressurize, a large amount of cold air gets into furnace, causes each section all to be influential, triggers production line scram signal, and the threshold value of furnace pressure and the scram or the scram of production line operation carry out the interlocking, in time stops the production line, prevents that a large amount of cold air from getting into furnace, and what triggered simultaneously also has the control that the hydrogen main valve was closed, stops a large amount of oxygen in hydrogen gas mixture gas and the air and mixes.

2. The method for operating the nitrogen interlocking control system of the hot galvanizing vertical annealing furnace according to claim 1, which is characterized in that: the preheating section, the heating section, the slow cooling section and the quenching section are respectively provided with two furnace pressure detecting instruments.

3. The method for operating the nitrogen interlocking control system of the hot galvanizing vertical annealing furnace according to claim 2, is characterized in that: the two furnace pressure detecting instruments are respectively arranged at the top and the bottom of each section.

4. The method for operating the nitrogen interlocking control system of the hot galvanizing vertical annealing furnace according to claim 1, which is characterized in that: the preheating section, the heating section, the slow cooling section and the quenching section are respectively provided with two furnace temperature detecting instruments.

5. The method for operating a nitrogen interlocking control system of a hot galvanizing vertical annealing furnace according to claim 4, which is characterized in that: the two furnace temperature detecting instruments are respectively arranged at the top and the bottom of each section.

Technical Field

The invention belongs to annealing equipment, and relates to an operation method of a nitrogen interlocking control system of a hot galvanizing vertical annealing furnace.

Background

The temperature of the annealing furnace is high during normal production, generally above 680-850 ℃, nitrogen charging is stopped when the nitrogen flow of the annealing furnace suddenly drops or the nitrogen flow is abnormally and erroneously operated, the furnace pressure of the annealing furnace drops, external cold air enters the annealing furnace, the damage to the annealing furnace is great, important equipment such as a refractory material, a lining, a furnace roller and the like of the annealing furnace are impacted firstly, band steel is quickly oxidized, a large amount of iron scales are generated, secondary impact is generated on the roller surface of the furnace roller and an inspection sensor, equipment in the annealing furnace is damaged permanently, the cost of maintenance and repair equipment is high, the maintenance cost is usually higher than that of purchasing new equipment, the construction time is long, the equipment function is reduced below a normal value, and the influence on production and maintenance is great.

The refractory material in the annealing furnace is contacted with cold air at high temperature, the refractory material and water molecules in the air are condensed, and the refractory material is rapidly cooled under thermal expansion to cause different degrees of damage such as shrinkage deformation, cracking and falling, displacement and the like, important equipment or a matrix in the annealing furnace is exposed under the protection of the refractory material, and the important equipment or the matrix material is damaged after losing the protection of the refractory material. The lining of the annealing furnace is usually made of stainless steel material, and deformation, bulging, local falling, cracking and the like occur in the case of thermal expansion and cold contraction. The annealing furnace radiant tubes are subjected to thermal expansion and cold contraction deformation and crack, and are used as important heating equipment inside the annealing furnace, if gas leakage can cause an annealing furnace explosion accident, the number of the annealing furnace radiant tubes is more than 100, the gas is required to be stopped during inspection or replacement, the gas supply pipelines are disassembled and connected, the construction amount is large, and the replacement detection time is long.

More serious, the strip steel in the annealing furnace is quickly oxidized under the condition of high temperature, a large amount of iron scales are generated, the iron scales are concentrated on the upper surface of the strip steel and adhered on the surface of a roller, and the strip steel generates relative friction with the running strip steel, so that the furnace is damaged. The length of the strip steel is generally more than 400 meters, a large amount of iron scales are concentrated on the bottom of the furnace, and are concentrated on a subsection area along with the operation of the roller and the strip steel, and are accumulated at the joint of a preheating section, a heating section, a slow cooling section, a rapid cooling section and a horizontal turning section, so that a strip breakage accident is caused in serious cases. A large amount of iron scale generated in the annealing furnace is adhered to a detection element in the furnace, and the accuracy of the detection element is influenced.

A large amount of iron oxide scales generated in the annealing furnace need to be cleaned for residues on transverse equipment arranged in the furnace, particularly, the cleaning difficulty between air box nozzles arranged in the furnace is high, the cleaning is not clean or the cleaning is not performed, the machine needs to be stopped for subsequent treatment, otherwise, the iron oxide scales fall onto strip steel or a roller surface during secondary production to cause secondary damage, and the product quality is directly influenced.

Disclosure of Invention

The invention provides an operation method of a nitrogen interlocking control system of a hot galvanizing vertical annealing furnace to solve the problems.

The invention has the technical scheme that the operation method of the nitrogen interlocking control system of the hot galvanizing vertical annealing furnace adopts the nitrogen pressure and the furnace pressure, the hydrogen main valve and the production line to carry out interlocking, the flow and the pressure at the nitrogen main valve are monitored, the nitrogen pressure of a sealing roller at the inlet of the annealing furnace, the abnormal reduction of the furnace pressure of a preheating section, a heating section, a slow cooling section, a rapid cooling section and a horizontal steering section, the oxygen content detection of the annealing furnace, the dew point detection of the annealing furnace, the interlocking of the furnace temperature and the nitrogen flow pressure in a high temperature mode to prevent the manual misoperation or the wrong stop, the minimum flow and the pressure of the nitrogen are controlled, and the furnace pressure is ensured to prevent cold air from entering the annealing furnace in a; the method comprises the steps that nitrogen pressure of an annealing furnace inlet sealing roller in an annealing furnace, a detection instrument is arranged in each section of a preheating section, a heating section, a slow cooling section, a rapid cooling section and a horizontal steering section, changes of the furnace pressure and the nitrogen pressure of the inlet sealing roller are detected, oxygen content and dew point are detected, actual data of one section are higher than or lower than set value data, the opening degree of an alarm unit and a nitrogen flow regulating valve is triggered to carry out remedial adjustment, the nitrogen furnace partial pressure is ensured to be normal, the nitrogen flow is regulated to the maximum value to influence production or can influence the limiting threshold value of the nitrogen pressure and the flow of a main pipe to meet production conditions, a shutdown cooling mode is triggered, the air-fuel ratio of a combustion system is regulated, the gas flow is reduced, the rotating speed of a fan of a cooling section is improved to accelerate; if nitrogen gas furnace partial pressure reduces very fast, unable pressurize, a large amount of cold air gets into furnace, causes each section all to be influential, triggers production line scram signal, and the threshold value of furnace pressure and the scram or the scram of production line operation carry out the interlocking, in time stops the production line, prevents that a large amount of cold air from getting into furnace, and what triggered simultaneously also has the control that the hydrogen main valve was closed, stops a large amount of oxygen in hydrogen gas mixture gas and the air and mixes.

Preferably, two furnace pressure detecting instruments are respectively arranged in the preheating section, the heating section, the slow cooling section and the quenching section.

Further, two furnace pressure detecting instruments are respectively arranged at the top and the bottom of each section.

Preferably, two furnace temperature detecting instruments are respectively arranged in the preheating section, the heating section, the slow cooling section and the fast cooling section.

Furthermore, two furnace temperature detecting instruments are respectively arranged at the top and the bottom of each section.

The invention has the beneficial effects that: the nitrogen pressure is interlocked with the furnace pressure, the hydrogen main valve and the production line sudden stop or quick stop, so that the damage to the annealing furnace and other equipment under the abnormal condition of the nitrogen is limited, and the loss is reduced. The pollution of a large amount of iron scales to important equipment in a hearth and the damage to the equipment are avoided, and the control of closing a hydrogen main valve is triggered at the same time, so that the explosion accident caused by the mixing of hydrogen in the nitrogen mixed gas and a large amount of oxygen in the air is avoided.

Drawings

FIG. 1 is a schematic view of a nitrogen interlock control system for a vertical annealing furnace according to the present invention;

FIG. 2 is a schematic view of the nitrogen control system of the vertical annealing furnace of the present invention;

FIG. 3 is a schematic view of the interlock for nitrogen flow error and misoperation in the vertical annealing furnace of the present invention;

FIG. 4 is a schematic view of the nitrogen pipe network pressure or flow abnormal deceleration shutdown interlock of the vertical annealing furnace of the present invention;

FIG. 5 is a schematic view of an emergency stop interlock for abnormal pressure or flow in a nitrogen pipe network of a vertical annealing furnace according to the present invention;

description of the symbols:

1. annealing furnace

100 annealing furnace body

101. Furnace temperature and pressure display of preheating section

102. Furnace temperature and pressure display of heating section

103. Furnace temperature and pressure display of slow cooling section furnace

104. Furnace temperature and pressure display of quenching zone

105. Furnace temperature and pressure display of horizontal turning section

106. Furnace inlet seal

107. Preheating section diffusing

108. Heating section diffusing

109. Slow cooling stage diffusion

110. Quench zone bleed

2. Nitrogen pipe network

200. Nitrogen manifold

201. Nitrogen quick-cutting valve

202. Nitrogen flow pressure detection

203. Nitrogen flow pressure display

204. Nitrogen-hydrogen mixed three-way regulating valve

205. Nitrogen-hydrogen protective gas main pipe of grate

3. Hydrogen pipe network

300. Hydrogen main pipe

301. Hydrogen fast-cutting valve

302. Hydrogen flow rate pressure detection

303. Hydrogen flow pressure display

400. Interlocking condition of nitrogen flow error or misoperation

401. Nitrogen flow regulating valve

402. Limitation of misoperation

403. Triggering interlock protection

404. Conditions of allowable movement of the apparatus

405. Fault recovery

406. Within the range of adjustment

407. Feedback signal determination of a regulated value

500. Nitrogen exception handling

501. Abnormal monitoring of pressure and flow of nitrogen pipe network

502. Judgment of abnormality caused by abnormal nitrogen in annealing furnace

503. Prompt contact peripheral emergency handling

504. Judgment of pressure trend of nitrogen pipe network of annealing furnace

505. Production with prompt of speed reduction

506. The production line speed reduction and shutdown conditions meet

507. Trigger shutdown interlock signal

600. Relatively abnormal treatment of nitrogen

601. The monitoring of the pressure and the flow of the nitrogen pipe network is relatively abnormal

602. Judgment of abnormality caused by abnormal nitrogen in annealing furnace

603. Immediate contact peripheral emergency handling

604. Annealing furnace nitrogen pipe network pressure fluctuation large trend judgment

605. Recoverable predicted time of alarm residual

606. Production line emergency shutdown

607. Triggering an emergency stop interlock signal

700. Nitrogen interlocking control system

701. Operation end of nitrogen interlocking control system

702. Interlock protection control module

703. Signal acquisition module

704. Two-stage control system

705. Furnace temperature detection

706. Furnace pressure detection

707. Oxygen content detection

708. Dew point detection

709. Gas flow detection

710. Air-fuel ratio variable detection

711. Production specification

712. Line speed

713. Production at reduced speed

714. Stopping at reduced speed

715. Quick stop

716. And (5) emergency shutdown.

Detailed Description

The invention is further described with reference to the following figures and detailed description.

The operation method of the nitrogen interlocking control system of the hot galvanizing vertical annealing furnace comprises the steps of interlocking by adopting nitrogen pressure and furnace pressure, a hydrogen main valve and production line sudden stop or quick stop, monitoring the flow and pressure at the nitrogen main valve, sealing roller nitrogen pressure at the inlet of the annealing furnace, abnormal reduction of furnace pressure of a preheating section, a heating section, a slow cooling section, a fast cooling section and a horizontal turning section, detection of oxygen content of the annealing furnace, detection of dew point of the annealing furnace, interlocking of furnace temperature and nitrogen flow pressure in a high-temperature mode to prevent manual misoperation or wrong stop, controlling the minimum flow and pressure of nitrogen and ensuring that the furnace pressure prevents cold air from entering the annealing furnace in a safety range; the method comprises the steps that nitrogen pressure of an annealing furnace inlet sealing roller in an annealing furnace, a detection instrument is arranged in each section of a preheating section, a heating section, a slow cooling section, a rapid cooling section and a horizontal steering section, changes of the furnace pressure and the nitrogen pressure of the inlet sealing roller are detected, oxygen content and dew point are detected, actual data of one section are higher than or lower than set value data, the opening degree of an alarm unit and a nitrogen flow regulating valve is triggered to carry out remedial adjustment, the nitrogen furnace partial pressure is ensured to be normal, the nitrogen flow is regulated to the maximum value to influence production or can influence the limiting threshold value of the nitrogen pressure and the flow of a main pipe to meet production conditions, a shutdown cooling mode is triggered, the air-fuel ratio of a combustion system is regulated, the gas flow is reduced, the rotating speed of a fan of a cooling section is improved to accelerate; if nitrogen gas furnace partial pressure reduces very fast, unable pressurize, a large amount of cold air gets into furnace, cause each section all to be influential, trigger production line scram signal, the threshold value of furnace pressure and the scram or the scram of production line operation carry out the interlocking, in time stop the production line, prevent that a large amount of cold air from getting into furnace, produce the pollution of a large amount of iron scale to important equipment in the furnace and cause the equipment to damage, the control that the total valve of hydrogen closed in addition that triggers simultaneously, stop the explosion accident after a large amount of oxygen mixes in hydrogen in the nitrogen gas mist and the air.

Preferably, the preheating section, the heating section, the slow cooling section and the quenching section are respectively provided with two furnace pressure detecting instruments and two furnace temperature detecting instruments, and the top and the bottom of each instrument are respectively provided with one instrument.

Referring to the attached figures 1 and 2, the lowest control quantity of nitrogen in a normal production state is interlocked with a production system, and the lowest control quantity of nitrogen in an abnormal state is interlocked with the production system, wherein the lowest control quantity of nitrogen in the normal production state can be compensated by reducing the speed of the nitrogen system, the nitrogen system is slowly reduced and can be recovered, the operation time is short, the abnormal fluctuation of the nitrogen system can be obviously recovered, and the abnormal fluctuation of the nitrogen system cannot be recovered and needs to be processed by emergency shutdown. The annealing furnace 1 is a large-scale device of a continuous hot galvanizing production line, is a main device integrating the detection and control functions based on a heating device and a plurality of instruments, and mainly performs recrystallization annealing and surface residual oil and residual iron oxidation reduction on production materials, and comprises a sealed medium pipeline assembly (the invention is mainly provided by interlocking a nitrogen system and a hydrogen system, and the others are omitted) at the periphery of a furnace body 100 of the annealing furnace, and the pressure maintaining of the annealing furnace consisting of a nitrogen pipe network 2 and a hydrogen pipe network 3 and the control of the atmosphere in the furnace provided by a grate nitrogen-hydrogen protective gas main pipe 205. The invention mainly adds an interlocking protection control module 702 connected with an operating end 701 of the nitrogen interlocking control system in the interlocking nitrogen interlocking control system 700 which is made aiming at the normal and abnormal processing methods and fault types, the interlocking protection control module 702 is connected with a secondary control system 704, a signal acquisition module 703 feeds back acquired data to the interlocking protection control module 702, the acquired feedback signals connected with the signal acquisition module 703 mainly comprise detection elements and sensors related to nitrogen interlocking control, such as furnace temperature detection 705, furnace pressure detection 706, oxygen content detection 707, dew point detection 708, gas quantity detection 709, air-fuel ratio variable detection 710 and the like, real values refreshed from time to time are fed back to the operating system and the interlocking control system, an annealing furnace 1 is connected with the secondary system 704 of the production line and the operating end 701 of the nitrogen interlocking control system to mutually send and transmit monitoring data, the normal operation of a nitrogen and hydrogen system of the annealing furnace is ensured, and the abnormality in the nitrogen control system mainly exists in that the normal production of a production line is impacted by the fluctuation or abnormal reduction or stop of the pressure of operators and peripheral pipe networks. A nitrogen inlet is provided by a nitrogen header pipe 200 in a nitrogen pipe network 2, a nitrogen flow rate and pressure detection 202 is connected through a nitrogen fast-switching valve 201 to detect the pressure and flow rate of nitrogen and display the nitrogen to an HMI picture or a field instrument display, the nitrogen is conveyed to each area of an annealing furnace 1 and displays the furnace temperature and the furnace pressure, five sections of detection and display are generally arranged in the furnace body of the annealing furnace, namely, a preheating section furnace temperature and furnace pressure display 101, a heating section furnace temperature and furnace pressure display 102, a slow cooling section furnace temperature and furnace pressure display 103, a fast cooling section furnace temperature and furnace pressure display 104 and a horizontal turning section furnace temperature and furnace pressure display 105 pass through a small-space strip steel-passing minimum gap in independent areas, the pressure of the whole furnace is measured and displayed, the nitrogen pressure output of a furnace inlet seal 106 is controlled, the sealing performance of the whole furnace is ensured, and the positive pressure control mode of the annealing furnace is. The branch of nitrogen gas pipeline still is connected with mixed three way control valve 204 of nitrogen hydrogen, the mixed three way control valve 204 of nitrogen hydrogen is connected with the hydrogen gas pipeline, through the output of adjusting the mixed hydrogen of mixed three way control valve 204 of nitrogen hydrogen and nitrogen gas, the mixed three way control valve 204 of nitrogen hydrogen and grate nitrogen hydrogen protection gas house steward 205 link to each other, the nitrogen hydrogen protection gas that obtains the required regulation stove atmosphere of annealing stove is carried to the stove nose and is blown through horizontal turning section direction, in proper order through quench zone, slow cooling section, heating section and preheating section. The hydrogen pipe network 3 mainly comprises a hydrogen fast-switching valve 301 and a hydrogen flow rate pressure detection 302 which are connected with a hydrogen main pipe 300, and then the hydrogen is conveyed to a preheating section, a heating section, a slow cooling section, a fast cooling section and a horizontal steering section of the annealing furnace to carry out reduction reaction on iron oxide generated on the surface of strip steel, so that the surface of the strip steel serving as a production material is cleaned, and preparation is made for production of the next procedure.

Referring to the interlocking schematic diagrams of nitrogen flow error or misoperation of the vertical annealing furnace shown in the attached drawings 1 and 2 and fig. 3, in the normal production process, the temperature of the strip steel is higher than 540-860 ℃, the temperature of the annealing furnace is higher than the temperature of the strip steel, and under high temperature, if a nitrogen control system receives serious results caused by misoperation of operators, the interlocking control system formed by connecting the nitrogen fast-cutting valve 201 and a secondary control system 704 of a production line has the advantages that when in normal production, the temperature of the annealing furnace is high, the furnace pressure is normal, the speed of the production line is normal, the oxygen content is normal, the dew point, the coal gas amount and the air-fuel ratio are normal, the adjustment amount of the nitrogen fast-cutting valve 201 is operated by mistake, the secondary control system 704 judges whether the production line is normal, under the normal condition, the input minimum limit adjustment amount is limited under the manual or automatic control mode, and the positive pressure operation of the annealing furnace, as shown in fig. 3, in the nitrogen flow rate error or malfunction interlock condition 400, the operator erroneously controls the nitrogen flow rate regulating valve, the interlock condition determines whether the production line is normal, the malfunction limiting condition 402 operates the detection feedback signal, if the interlock protection 403 is triggered to refuse to execute the operation command normally, and the operator is prompted with the reason for the limitation of the operator, which indicates that the operation fails, ensures the smooth operation of the whole nitrogen system, prevents the serious shutdown accident caused by misoperation, the negative pressure of the annealing furnace is caused by low nitrogen flow at high temperature, a large amount of cold air enters a hearth, the oxygen in the air and high-temperature strip steel generate oxidation reaction, a large amount of iron oxide scales are separated out, the iron oxide scales in the vertical annealing furnace fall to the inside of the hearth and the strip steel, and serious consequences of detection errors occur on detection elements and instruments of the annealing furnace. A large amount of iron scale falls on the surface of the roller in the furnace and adheres to the surface of the roller along with the rotation of the roller, and the iron scale generates friction between the strip steel and the surface of the roller to cause the damage of the surface of the roller. After the program in the interlocking state runs, whether the equipment is in an allowable adjustable variable or can be operated after necessary equipment processing is taken is judged, equipment allowable movable conditions 404 are judged in the interlocking conditions, if the equipment is allowable, the next adjustment is carried out in an adjustment range 406, adjusted parameters are fed back, whether a feedback signal of an adjustment value is normal is judged 407, if the condition is not judged, the fault equipment is listed, an operator is prompted to recover from the equipment fault 405, a next command is allowed after the fault is recovered, and the output of the adjustment range 406 is continued. The method is characterized by comprising the steps of judging whether the production line equipment is normal or not, judging whether the interlock detection of the annealing furnace diffusing equipment is normal or not, normally, displaying preheating section diffusing 107, heating section diffusing 108, slow cooling section diffusing 109 and fast cooling section diffusing 110, displaying preheating section furnace temperature and furnace pressure 101 normally, displaying heating section furnace temperature and furnace pressure 102 normally, displaying slow cooling section furnace temperature and furnace pressure 103 normally, displaying fast cooling section furnace temperature and furnace pressure 104 normally, displaying horizontal turning section furnace temperature and furnace pressure 104 normally, displaying furnace inlet seal 106 normally, enabling the furnace pressure to be at high pressure, and adjusting the nitrogen flow to have an operable allowance.

Referring to attached figures 1, 2 and 4, the interlocking schematic diagram of the vertical annealing furnace for the deceleration stop in case of abnormal nitrogen pipe network pressure or abnormal flow comprises that the nitrogen abnormal processing 500 comprises the impact of the pressure and flow fluctuation of the nitrogen system caused by external factors, the detection element for detecting the pressure and flow of the nitrogen main pipe detects the nitrogen flow pressure 202, the detection data is fed back to the secondary system, the interlocking protection control module 702 is triggered when the detection data is lower than the minimum range value set by the system or is lower than the warning value of the nitrogen pressure and flow, the flow monitoring abnormity 501 starts the execution of the interlocking program, the interlocking condition judges whether the production line is normal, the abnormal annealing furnace nitrogen causes the abnormal judgment 502 to operate the interlocking condition, the feedback signals of the production line and the annealing furnace are detected, the detection signals feed back the acquired data to the interlocking protection control module 702 through the signal acquisition module 703, the signal acquisition module 703 is connected with detection elements and sensors related to nitrogen interlocking control, such as acquisition feedback signal furnace temperature detection 705, furnace pressure detection 706, oxygen content detection 707, dew point detection 708, gas quantity detection 709, air-fuel ratio normal variable detection 710 and the like, which are connected with the signal acquisition module, feeds back real values refreshed from time to an operating system and an interlocking control system, the interlocking program judges that main items have a descending trend, triggers judgment 504 of the pressure trend of the nitrogen pipe network of the annealing furnace to operate, and triggers a prompt to contact with an emergency processing program of peripheral emergency processing 503 operators to perform contact adjustment if other data are detected to be normal, and keeps the pressure and flow of the nitrogen pipe network 2. The judgment 504 of the pressure trend of the nitrogen pipe network of the annealing furnace calculates whether the remaining time of the pressure reduction trend of the nitrogen pipe network from the lowest control standard meets the production conditions, if the condition for triggering the production line to slow down and stop continuously falls below the alarm value meets 506, the production line starts a speed-down stop program and triggers a stop interlocking signal to process the stop, if the judgment 504 of the pressure trend of the nitrogen pipe network of the annealing furnace is triggered and the trend has the remaining time, the operator is prompted to reduce the speed for production, the pressure and flow requirements of the nitrogen pipe network 2 are recovered in a short time in connection with peripheral elimination treatment accidents, the furnace temperature, the oxygen content and the furnace pressure of the annealing furnace are reduced within an effective control range, the production is kept through the reduction of the speed of the production line, the production can be recovered through the recovery of the nitrogen pressure and the flow, after normal production parameters are recovered, the nitrogen interlocking control system operation end 701 can automatically terminate interlocking conditions and feed back the interlocking conditions to the secondary control system.

Referring to attached figures 1, 2 and 5, the interlocking schematic diagram of the abnormal pressure or flow of the nitrogen pipe network of the vertical annealing furnace of the invention is shown, the abnormal handling 600 of nitrogen gas comprises the impact of the pressure and flow of the nitrogen system caused by the fluctuation of the external factors to the production line, the detection component for detecting the pressure and flow of the nitrogen main pipe is the nitrogen flow pressure detection 202, the detection data is fed back to the secondary system, the interlocking protection control module 702 is triggered by the alarm value which is lower than the minimum range value set by the system or lower than the nitrogen pressure and flow, the abnormal monitoring 601 of the pressure and flow of the nitrogen pipe network 2 and the nitrogen main pipe 200 in the interlocking condition starts the execution of the interlocking program, the interlocking condition judges whether the production line is normal or not, the abnormal nitrogen gas causes the abnormal judgment 602 to operate the interlocking condition, and the feedback signals of, the detection signal is fed back to the interlock protection control module 702 through the signal acquisition module 703, the detection elements and sensors related to nitrogen interlock control, such as the acquisition feedback signal furnace temperature detection 705 connected with the signal acquisition module 703, the furnace temperature high, the furnace pressure detection 706 low, the oxygen content detection 707 high, the dew point detection 708 high, the gas quantity detection 709 normal, the air-fuel ratio normal variable detection 710, feed back the actual value refreshed from time to the operating system and the interlock control system, the interlock program judges that the main item has a large descending trend, triggers the nitrogen pipe network pressure fluctuation large trend judgment 604 to operate, if other data are normal, the nitrogen fluctuation large amount triggers to immediately contact peripheral emergency processing 603 operators to emergently contact peripheral nitrogen abnormity, and the nitrogen can not be provided for various reasons such as peripheral equipment abnormal damage or pipeline external force disconnection, the pressure and flow of the nitrogen pipe network 2 cannot be maintained. The judgment 604 of the great pressure fluctuation trend of the nitrogen pipe network of the annealing furnace calculates that the pressure of the nitrogen pipe network is reduced rapidly and can not meet the continuous production condition, directly triggers an emergency stop signal 606 of the production line after the nitrogen flow rate is lower than the alarm value of the emergency stop of the production line, triggers an emergency stop interlocking signal 607, open emergency start to the equipment of relevant shut down after the scram of production line triggers, for example the annealing stove needs operation stove entry seal roller under high temperature, the backup roll of the interior little roller footpath of stove etc. prevents that the roller from bending deformation under high temperature, close hydrogen gas fast cut valve 301 and nitrogen hydrogen mixture three way control valve 204 immediately, less cold air gets into in the stove and mixes the danger that the back emergence was exploded with hydrogen, start annealing stove coal gas fast cut mode rapid cooling, the very big fan rotational speed of slow cooling section and quench section in the stove, improve the cooling capacity of belted steel, close the opening and stopping of emergency stop equipment such as electric heater in the stove. The alarm residual recoverable predicted time 605 is prompted before the nitrogen pipe network pressure fluctuation major trend judgment 604 of the annealing furnace triggers the emergency stop signal, in order to reduce accident loss, in the shortest time, equipment needing manual operation is arranged and operated by personnel, the accident alarm residual recoverable predicted time 605 is also beneficial to the start of the interlocking protection of some important equipment before the emergency stop production line, the interlocking signal of the more important equipment on the production line, such as the equipment of a polishing machine, a withdrawal straightening machine, a roller coater and the like, can be added into the operation end 701 of the nitrogen interlocking control system in the shortest time, the limited emergency stop signal trigger can be adjusted through the production specification 711 and the production line speed 712, the secondary control system 704 directly executes an operation instruction, and the control instruction of the interlocking protection control module 702 can be continued until all the equipment and the production process after the emergency stop operate normally, the accident is not further expanded, and the emergency procedure of 600 for abnormal handling of nitrogen is terminated after proper handling has been performed.

After emergency shutdown, the air-fuel ratio of gas and air is automatically changed, the feedback of the air-fuel ratio variable detection 710 is detected at any time, and the strip steel in the furnace is rapidly cooled. The nitrogen humidification system is immediately shut down after the emergency shutdown, so that a large amount of water vapor is prevented from being generated inside the furnace nose, and the feedback value of the dew point detection 708 fed back from time to time is observed. After the sudden stop signal is triggered, insulation reduction and short circuit tripping accidents of a large amount of iron scales generated in the annealing furnace can be caused to the exposed electric heater, the annealing furnace cannot be put into use, power cut processing is required immediately, power transmission can be recovered after the insulation is tested and meets the conditions after the iron scales are cleaned, and the equipment can be added into the interlocking condition. After the sudden stop signal is triggered, a large amount of iron oxide scales generated in the annealing furnace damage detection equipment of the deviation correction equipment in the furnace, the detection equipment can be restored after the conditions are met, and the equipment can be added into the interlocking conditions.